Calculation and design of thermal networks. Hydraulic calculation of thermal networks. Heat consumption for DHW

18.10.2019

course work

on the course "Heat networks"

on the topic: "Design of thermal networks"

Exercise

for term paper

on the course "Heat networks"

Design and calculate the heat supply system of the district of the city of Volgograd: determine the heat consumption, select the heat supply scheme and the type of heat carrier, and then make hydraulic, mechanical and thermal calculations of the heat scheme. The data for calculating option No. 13 are presented in Table 1, Table 2 and Figure 1.

Table 1 - Initial data

Value Designation Value Value Designation Designation Value Outdoor temperature (heating) -22 Furnace performance 40 Outdoor air temperature (ventilation) -13Kiln operating hours per yearhours8200Number of inhabitants 25 000Specific gas consumption 64Number of residential buildings 85Specific consumption of liquid fuel kg/t38Number of public buildings 10Consumption of oxygen blown into the bath 54Volume of public buildings 155,000Iron ore consumptionkg/t78Volume of industrial buildings 650,000Pig iron consumptionkg/t650Number of steelmaking shops2Scraper consumptionkg/t550Number of machine shops2Batch consumptionkg/t1100Number of repair shops2Exhaust gas temperature to the boiler 600Number of thermal shops2Exhaust gas temperature after the boiler 255Number of railway depots3Air flow rate before the boiler1.5Number of warehouses3Airflow rate after the boiler1.7

Figure 1 - Scheme of heat supply of the district of the city of Volgograd

Table 2 - Initial data

Distances of plots, kmElevation differences on the ground, m 01234567OABVGDEZH 47467666079268997

abstract

Course work: 34 p., 1 fig., 6 tables, 3 sources, 1 appendix.

The object of study is the heating system of the city of Volgograd.

The purpose of the work is to master the calculation methodology for determining the heat consumption for heating, ventilation and hot water supply, the choice of heat supply scheme, calculation of the heat source, hydraulic calculation of heat networks, mechanical calculation, thermal calculation of heat networks.

Research methods - execution and analysis of calculations to determine heat consumption, coolant flow rates, design line, non-design line, number of supports, heat pipe compensators, elevator selection.

As a result of this work, the duration of the heating season, the minimum heat consumption for heating, thermal load for heating, ventilation and air conditioning are seasonal and depend on climatic conditions. Also, the heat of flue gases of open-hearth furnaces was calculated, a waste heat boiler was selected, the economic efficiency of the waste heat boiler and fuel savings were determined, and a hydraulic calculation of heat networks was carried out. The number of supports was also calculated, the elevator was selected, and the calculation was made heater.

Number of inhabitants, elevator, heating, ventilation, pipeline, temperature, pressure, heating networks, hot water supply, plot, main, coolant

Calculation of heat consumption

1 Calculation of thermal loads

1.1 Heat consumption for heating

1.2 Heat consumption for ventilation

1.3 Heat consumption for DHW

2 Annual consumption heat

3 Heat load duration curve

Choice of heat supply scheme and type of heat carrier

Heat source calculation

1 Flue gas heat

2 Selecting a waste heat boiler

3 Determination of fuel economy and economic efficiency of the waste heat boiler

Hydraulic calculation of the heat network

1 Determination of the coolant flow

2 Pipeline diameter calculation

3 Calculation of the pressure drop in the pipeline

4 Building a piezometric graph

Mechanical calculation

Thermal calculation

Link List

Introduction

Heat supply is one of the main subsystems of the energy sector. About 1/3 of all fuel and energy resources used in the country are spent on heat supply to the national economy and the population.

The main directions for improving this subsystem are the concentration and combination of heat and electricity production (cogeneration) and the centralization of heat supply.

Heat consumers are housing and communal services and industrial enterprises. For housing and communal facilities, heat is used for heating and ventilation of buildings, hot water supply; for industrial enterprises, in addition, for technological needs.

1. Calculation of heat consumption

1.1 Calculation of thermal loads

Heat loads for heating, ventilation and air conditioning are seasonal and dependent on climatic conditions. Technological loads can be both seasonal and year-round (hot water supply).

1.1.1 Heat consumption for heating

The main task of heating is to maintain the internal temperature of the premises at a given level. To do this, it is necessary to maintain a balance between the heat losses of the building and the heat gain.

The heat loss of a building mainly depends on heat loss through heat transfer through external enclosures and infiltration.

where - heat loss by heat transfer through external fences, kW;

Infiltration coefficient.

Heat consumption for heating residential buildings determined by the formula (1.1), where the heat loss by heat transfer through external fences is calculated by the formula:

where is the heating characteristic of the building, kW / (m3 K);

External volume of a residential building, m3;

The total volume of residential buildings is determined by the formula:

where - number of inhabitants, persons;

Volumetric coefficient of residential buildings, m3/person. Let's take it equal.

To determine the heating characteristics, it is necessary to know the average volume of one building, then from Appendix 3 we have.

According to Appendix 5, we find that. The infiltration coefficient for this type of building is acceptable. Then the heat consumption for heating residential buildings will be:

Heat consumption for heating public buildings is also calculated by formulas (1.1) and (1.2), where the volume of buildings is assumed to be equal to the volume of public buildings.

The average volume of one public building.

From Appendix 3 we have. According to Appendix 5, we determine that.

The infiltration coefficient for this type of building is acceptable. Then the heat consumption for heating public buildings will be:

Heat consumption for heating industrial buildings calculates according to the formula:

Average volume of one industrial building:

According to this value from Appendix 3, we have the values of heating characteristics, which are given in Table 1.1.

Table 1.1 - Heating characteristics of industrial buildings

We accept the infiltration coefficient. The internal air temperature in the workshops should be , in the depot - , and in the warehouse - .

Heat consumption for heating industrial workshops:

Heat consumption for heating the railway depot and warehouses:

The total heat consumption for heating industrial buildings will be:

Total heat consumption for heating will be:

Heat consumption at the end of the heating period:

where is the outside temperature of the beginning and end of the heating period;

Estimated temperature inside the heated building.

Hourly heat consumption at the end of the heating period:

Hourly heat consumption for heating:

1.1.2 Heat consumption for ventilation

An approximate calculation of the heat consumption for ventilation can be carried out according to the formula:

where is the ventilation characteristic of the building, kW/(m3 K);

External volume of the building, m3;

Internal and external temperatures, °C.

Heat consumption for ventilation of public buildings.

In the absence of a list of public buildings, it can be taken for the total volume of all public buildings. Thus, the heat consumption for ventilation of this type of building will be:

Heat consumption for ventilation of industrial buildings calculated according to the following formula:

The average volume of one industrial building and, accordingly, from Appendix 3 we find the ventilation characteristic of the building (table 1.2).

Table 1.2 - Ventilation characteristics of industrial buildings

WorkshopSteel-smeltingMechanicalRepairThermalDepot RailwayWarehouse 0,980,180,120,950,290,53

Heat consumption for ventilation of the railway depot and warehouses:

Heat consumption for ventilation of industrial workshops:

The total heat consumption for ventilation of public buildings will be:

The total cost of ventilation will be:

The heat consumption for ventilation at the end of the heating period is determined by the formula (1.5):

Hourly heat consumption for ventilation at the end of the heating season:

Hourly heat consumption:

1.1.3 Heat consumption for DHW

Hot water supply is very uneven both during the day and during the week. Average daily heat consumption for domestic hot water supply:

where - the number of inhabitants, people;

Consumption rate hot water s per inhabitant, l/day;

Hot water consumption c for public buildings per resident of the district, l/day;

Heat capacity of water: .

Let's take and. Then we have:

Hourly heat consumption for hot water supply:

Average heat consumption for hot water supply in summer period:

where is the temperature of cold tap water in the summer, ° С ();

Coefficient that takes into account the decrease in water consumption for hot water supply in the summer in relation to the water consumption in the heating period ().

Then:

Hourly heat consumption:

1.2 Annual heat consumption

The annual heat consumption is the sum of all heat loads:

where is the annual heat consumption for heating, kW;

Annual heat consumption for ventilation, kW;

Annual heat consumption for hot water supply, kW.

The annual heat consumption for heating is determined by the formula:

where is the duration of the heating period, s;

Average heat consumption for the heating season, kW:

where is the average outdoor temperature of the heating period, °С

According to Appendix 1, we find and. From Appendix 2 for the city of Volgograd, we write out the standing hours of the average daily temperatures in the year (Table 1.3).

Table 1.3 - Number of hours for the heating period with an average daily outdoor temperature

Temperature, ° С -20 and below -15 and below -10 and below -5 and below 0 and below + 5 and below + 8 and below

Then the annual heat consumption for heating will be:

The annual heat consumption for ventilation is calculated as follows:

where - the duration of ventilation during the heating period, s;

Average heat consumption for ventilation for the heating season, kW:

The duration of ventilation operation is taken for public buildings. Then the annual heat consumption for ventilation will be:

The annual heat consumption for hot water supply is determined by the formula:

where - the duration of the hot water supply during the year, s.

Accept. Then the annual heat consumption for hot water supply will be:

The annual heat consumption for heating, ventilation and hot water supply will be:

1.3Heat Load Duration Graph

The heat load duration graph characterizes the dependence of heat consumption on the outside air temperature, and also illustrates the level of total heat consumption throughout the entire heating period.

The following data is required to plot the heat load graph:

® duration of the heating season

®estimated hourly heat consumption for heating

®minimum hourly heat consumption for heating

®estimated hourly heat consumption for ventilation

®minimum hourly heat consumption for heating

2. Choice of heat supply scheme and type of heat carrier

The main heat pipelines are shown in Figure 2.1. As you can see, this is a beam heating network, in which individual main branches are interconnected (A-B and A-D, A-D and D-C, etc.) in order to avoid interruptions in the supply of heat.

Figure 2.1 - Heat supply scheme of the city of Volgograd

The heat source is a waste heat boiler that uses the secondary resources of an open-hearth furnace. The heat carrier is water.

With district heating, three main schemes are used: independent, dependent with water mixing and dependent direct-flow. In our case, we will install a dependent circuit with water mixing to connect the heating system to external heat pipes. Here, return water from the heating system is mixed with high-temperature water from the outdoor heat supply pipe using an elevator.

3. Heat source calculation

The heat source is an open-hearth furnace, the secondary resources of which are used by the waste heat boiler for heating. The secondary energy resources of steelmaking used for district heating are the heat of flue gases and the heat of the elements of the steelmaking furnace.

An open-hearth furnace operating with a scrap-ore process is heated by a mixture of natural gas and fuel oil with oxygen supplied to the bath. The composition of fuels is given in Table 3.1.

Table 3.1 - Composition of fuel burned in an open-hearth furnace

Gas,% 95.72.850.11.35 Fuel oil, %85.512.40.50.50.11.0

3.1 Flue gas heat

The exhaust gases of the open-hearth furnace after the regenerators have a temperature of 605°C and are used to generate steam in waste heat boilers. The amount of heat of exhaust gases is determined per 1 ton of steel. Therefore, to determine the enthalpy of flue gases, it is necessary to determine the volumes of their individual components per 1 ton of steel. Theoretical oxygen consumption for burning 1 m 3gaseous fuel is calculated by the formula:

We have:

Theoretical oxygen consumption for burning 1 kg of liquid fuel:

The total theoretical oxygen consumption for fuel combustion per 1 ton of steel is calculated by the formula:

where is the consumption of gaseous fuel, ;

Liquid fuel consumption, kg/t.

Also, oxygen is spent on the oxidation of metal impurities and on the afterburning of carbon monoxide released from the bath. The amount thereof, taking into account the oxygen of iron ore, will be:

where - ore consumption per 1 ton of steel, kg;

The amount of burnt carbon per 1 ton of steel, kg:

where is the consumption of cast iron and scrap per 1 ton of steel, kg;

Thus, the amount of burnt carbon will be:

The volume of oxygen in the exhaust gases at the outlet of the regenerator is calculated as:

where is the coefficient of air flow to the waste heat boiler.

Let us determine the volumes of other gases in the combustion products. The volume of triatomic gases in the combustion products of a mixture of gaseous and liquid fuels is calculated by the formula:

Triatomic gases are also separated from the charge:

where is the amount and released from the bath per 100 kg of charge, kg;

Density and ();

Charge consumption per 1 ton of steel, kg.

For scrap ore process

The total volume of triatomic gases is defined as:

The volume of water vapor in the combustion products of the fuel mixture will be:

where is the specific consumption of pure oxygen blown into the bath, .

Isolation of water vapor from the mixture:

where is the amount released from the bath per 100 kg of charge, kg;

Density of water vapor.

For scrap ore process.

The volume of water vapor in the exhaust gases is calculated similarly to the volume of diatomic gases according to formula (3.9):

The volume of nitrogen in the flue gases:

Thus, the enthalpy of gases at the outlet of the regenerator per 1 ton of steel will be:

where is the gas temperature up to the waste heat boiler, °С;

Volumetric heat capacities of the corresponding gases, kJ/(m3 K).

3.2 Selecting a waste heat boiler

The annual heat output with flue gases will be:

where is steel production per year, i.e.

Then the possible utilization of exhaust gases is determined by the formula:

where is the enthalpy of flue gases at the outlet of the waste heat boiler, GJ/t. When determining the enthalpy of flue gases at the outlet of the waste heat boiler, it should be taken into account that there are air leaks in the waste heat boiler, that is, the air flow rate after the boiler is 1.7, which means that the volumes of oxygen and nitrogen will increase:

To select a waste heat boiler, it is necessary to determine the hourly flow rate of flue gases:

where is the operating time of the open-hearth furnace per year, h.

The average hourly consumption of flue gases at the inlet to the waste heat boiler will be:

At the outlet of the waste heat boiler:

According to the application, we select KU-100-1 with a throughput of 100,000 m3 / h.

3.3 Determination of fuel economy and economic efficiency of the waste heat boiler

The enthalpy of gases at the outlet of the waste heat boiler is:

This means that the possible utilization of exhaust gases for the year will be:

With the thermal direction of utilization of secondary energy resources, the possible heat generation is determined by the formula:

where is a coefficient that takes into account the discrepancy between the mode and operating time of the utilization plant and the process unit;

Coefficient that takes into account the heat loss of the utilization plant to the environment.

At and the possible heat generation will be:

Possible fuel economy is calculated by the formula:

where is the utilization factor of the output; - specific fuel consumption for heat generation at the replaced unit, tce/GJ:

where is the efficiency of the replaced power plant, with the indicators of which the efficiency of the use of secondary energy resources is compared.

At and we have the following fuel economy:

Estimated savings from the use of secondary energy resources is determined from the expression:

where is a coefficient that additionally takes into account the reduction in current costs, in addition to fuel savings, caused by a decrease in the capacity of the main power plants as a result of their replacement with utilization plants;

Factory cost of saved fuel at current list prices and tariffs, UAH/tce;

Specific costs for the operation of recycling plants, UAH / GJ;

E - normative coefficient of efficiency of capital investments (0.12-0.14);

Capital investments in replaced power and utilization plants, UAH

Costs are shown in table 3.2

Table 3.2 - Costs

ParameterDesignationValueCapital costs for KU-100-1 UAH 160 million 45 UAH/GJ Cost of reference fuel 33,000 UAH/tce

The investment in a replacement plant to produce the same amount of steam is:

Then the estimated savings from the use of secondary energy resources will be equal to:

4. Hydraulic calculation of the heat network

The task of hydraulic calculation includes determining the diameter of the pipeline, the pressure drop between individual points, determining the pressure at various points, linking all points of the system in order to ensure acceptable pressures and the required pressures in the network and at subscriptions in static and dynamic modes.

4.1 Determining the coolant flow

The coolant consumption in the network can be calculated by the formula:

where - thermal power heating systems, kW;

Estimated supply and return water in the heating system, °С;

Heat capacity of water, kJ/(kg °C).

For section 0, the thermal power will be equal to the sum of heat consumption for heating and ventilation, that is. The calculated temperatures of direct and return water will be 95°С and 70°С. Thus, the water flow for section 0 will be:

For other sections, the calculation of heat carrier flow rates is summarized in Table 4.1 heat supply heat consumption heat carrier load

4.2 Calculation of pipeline diameter

Estimate the preliminary pipeline diameter using the mass flow formula:

where is the coolant velocity, m/s.

We will take the speed of water movement 1.5 m/s, the density of water at an average temperature in the network of 80-85 ° C will be. Then the diameter of the pipeline will be:

From a number of standard diameters, we take a diameter of 68 0x9 mm. We perform the following calculations for it. The initial dependence for determining the specific linear pressure drop in the pipeline is the equation D Arcee:

where is the coefficient of hydraulic friction;

Medium speed, m/s;

Medium density, kg/m3;

Mass flow, kg/s.

The coefficient of hydraulic friction generally depends on the equivalent roughness and the Reynolds criterion. To transport heat, rough steel pipes are used, in which turbulent flow is observed. Empirically obtained dependence of the coefficient of hydraulic friction steel pipes on the Reynolds criterion and relative roughness is well described by the universal equation proposed by A.D. Altshulem:

where is the equivalent roughness, m;

Internal diameter of the pipeline, m;

Reynolds criterion.

The equivalent roughness for water networks operating under normal operating conditions is. The Reynolds criterion is calculated by the formula:

where is kinematic viscosity, m2/s.

For a temperature of 80°C, the kinematic viscosity of water is. Thus, we have:

We assume that the pipeline operates in a quadratic region. Let's find a new diameter value using the formula:

Thus, the previously assumed diameter is correct.

4.3 Calculation of the pressure drop in the pipeline

The pressure drop in the pipeline can be represented as the sum of two terms: the linear drop and the drop in local resistances.

Pressure drop depending on the slope of the pipeline, Pa.

The pressure drop due to friction is calculated by the formula:

where λ =1.96 is the coefficient of friction for new pipes with an absolute roughness of 0.5 mm;

l is the length of the pipeline section, m;

ν - speed in the section, we take 1.5 m / s as a constant for all sections; - pipeline diameter, d = 0.5 m.

The pressure drop depending on the slope of the pipeline is calculated by the formula:

Where m is the mass of water passing through the site, kg / s; is the height difference between the sites, m.

To calculate the coolant flow rates, we will use the second Kirchhoff law, according to which the sum of the pressure losses for a closed circuit is 0.

We set arbitrary values of water consumption by sections:

Let us determine the resistances in the corresponding sections according to the formula:

Let us determine the magnitude of the head loss discrepancy:

Because then a recalculation is needed. To do this, we need a correction flow:

Let us find the discrepancy of pressure losses of the second approximation:

For a more precise definition, let's recalculate:

We find the following water costs:

For a more accurate definition, let's do one more recalculation:

We find the following water costs:

Table 4.1 - Coolant flow rates for sections of the main heating network

PlotIT-AA-BB-DA-GG-ZHB-VV-EG-VHeat power, MW51.52126.90711.54124.84812.34820.73727.62218.271 Water consumption491.85256.8716110.18237.2184117.891963.97162 7174.4284 4.4 Building a piezometric graph

We set the values of pressure (pressure) at the end of the sections:

Residential area E: H=30 m (residential 9-storey building);

Railway depot, warehouses L: H=10 m;

Industrial area Zh: H=20 m.

Find the pressure at point B:

We select the “+” sign, section D where the coolant is transported above section B.

The pressure at point B will be:

Find the pressure at point B:

Find the pressure at point G:

Find the pressure at point A:

Find the pressure at point O:

Based on the data obtained, we build a piezometric graph Appendix A

5. Mechanical calculation

Mechanical calculation includes:

calculation of the number of supports;

calculation of heat pipe compensators;

elevator selection calculation.

5.1 Calculation of the number of supports

When calculating the number of pipeline supports, they are considered as a multi-span beam with a uniformly distributed load.

Vertical force;

- horizontal force.

occurs only at elevated pipelines and is determined by wind speed:

Aerodynamic coefficient averages k=1.5. For Volgograd, the velocity head is 0.26 kPa. Sometimes for elevated pipelines it is necessary to take into account the pressure of the snow cover of 0.58-1kPa.

Maximum bending moment:

Bending stress; kPa

W is the equatorial moment of resistance of the pipe.

Then: - distance between supports, m

safety factor,

Pipe weld strength factor,

The number of supports is determined by the formula:

A pipeline resting on two supports bends.

x - deflection arrow:

E is the modulus of longitudinal elasticity.

I - equatorial moment of inertia of the pipe,

5.2 Calculation of heat pipe compensators

In the absence of compensation for severe overheating, the pipe wall becomes stressed.

where E is the modulus of longitudinal elasticity;

Linear expansion coefficient,

- air temperature

In the absence of compensation, stresses may arise in the pipeline that significantly exceed the allowable ones and which can lead to deformation or destruction of the pipes. Therefore, temperature compensators are installed on it various designs. Each compensator is characterized by its functional ability - the length of the section, the elongation of which is compensated by the compensator:

where=250-600mm;

- air temperature

Then the number of compensators on the calculated section of the route:

5.3 Elevator selection calculation

When designing elevator inputs, as a rule, one has to meet the following tasks:

determination of the main dimensions of the elevator;

pressure difference in the nozzle by a given coefficient.

When solving the first problem, the given values are: heat load heating system; calculated outdoor air for designing heating temperature of network water in the falling pipeline and water after the heating system; pressure loss in the heating system in the considered mode.

The calculation of the elevator is performed:

Consumption of network and mixed water, kg / s:

where c is the heat capacity of water, J / (kg; c \u003d 4190 J / (kg.

Consumption of injected water, kg/s:

Elevator mixing ratio:

Conductivity of the heating system:

mixing chamber diameter:

Due to the possible inaccuracy of the dimensions of the elevator, the necessary pressure difference in front of it should be provided with a certain margin of 10-15%.

Nozzle outlet diameter, m

6. Thermal calculation of heat networks

Thermal calculation of thermal networks is one of the most important sections of the design and operation of thermal networks.

Tasks of thermal calculation:

determination of heat losses through the pipeline and insulation to the environment;

calculation of the temperature drop of the coolant when it moves along the heat pipeline;

determination of the efficiency of thermal insulation.

6.1 Above ground installation

For above-ground laying of heat pipelines heat loss calculated by the formulas for a multilayer cylindrical wall:

where t is the average temperature of the coolant; °C

Temperature environment; °C

Total thermal resistance of the heat pipe; m

In an insulated pipeline, heat must pass through four resistances connected in series: the inner surface, the pipe wall, the insulation layer, and the outer surface of the insulation.

cylindrical surface is determined by the formula:

Internal diameter of the pipeline, m;

Outer diameter of insulation, m;

and - heat transfer coefficients, W/.

6.2 underground laying

In underground heat pipelines, one of the inclusions of thermal resistance is soil resistance. When calculating the ambient temperature, the natural temperature of the soil at the depth of the heat pipeline axis is taken as the ambient temperature.

Only at small depths of the heat pipeline axis, when the ratio of the depth h to the pipe diameter is less than d, the natural temperature of the soil surface is taken as the ambient temperature.

The thermal resistance of the soil is determined by the Forheimer formula:

where \u003d 1.2 ... 2.5 W \

General specific heat losses, W/m

first heat pipe:

Second heat pipeline:

6.3 Channelless piping

With channelless laying of heat pipelines, the thermal resistance consists of series-connected resistances of the insulation layer, the outer surface of the insulation, the inner surface of the channel, the walls of the channel and the soil.

6.4 Heat calculation of the heater

The thermal calculation of the heater consists in determining the heat exchange surface of the unit of a given capacity, or in determining the capacity for given design calculations and initial parameters of the coolant. The hydraulic calculation of the heater is also important, which consists in determining the pressure loss of the primary and secondary coolant.

Hydraulic calculation of water heating networks is carried out in order to determine the diameters of pipelines, pressure losses in them, linking the thermal points of the system.

The results of the hydraulic calculation are used to build a piezometric graph, select schemes for local heating points, select pumping equipment and technical and economic calculations.

The pressure in the supply pipelines, through which water with a temperature of more than 100 0 C moves, must be sufficient to prevent vaporization. The temperature of the coolant in the line is assumed to be 150 0 C. The pressure in the supply pipelines is 85 m, which is sufficient to prevent vaporization.

To prevent cavitation, the pressure in the suction pipe of the network pump must be at least 5 m.

With elevator mixing at the subscriber input, the available pressure must be at least 10-15 m.

When the coolant moves along horizontal pipelines, a pressure drop is observed from the beginning to the end of the pipeline, which consists of a linear pressure drop (friction loss) and pressure losses in local resistances:

Linear pressure drop in a pipeline of constant diameter:

Pressure drop in local resistances:

Reduced pipeline length:

Then formula (14) will take the final form:

Let's determine the total length of the settlement highway (sections 1,2,3,4,5,6,7,8):

We will carry out a preliminary calculation (Consists in the determination of diameters and speeds). The share of pressure losses in local resistances can be approximately determined by the formula of B.L. Shifrinson:

where z \u003d 0.01 is the coefficient for water networks; G - coolant flow in the initial section of the branched heat pipeline, t/h.

Knowing the proportion of pressure losses, it is possible to determine the average specific linear pressure drop:

where is the available pressure drop to all subscribers, Pa.

According to the assignment, the available pressure drop is given in meters and is equal to? H \u003d 60 m. pressure losses are distributed evenly between the supply and return lines, then the pressure drop on the supply line will be equal to? H \u003d 30 m. Let's translate this value into Pa as follows:

where = 916.8 kg / m 3 - the density of water at a temperature of 150 0 C.

Using formulas (16) and (17), we determine the proportion of pressure losses in local resistances, as well as the average specific linear pressure drop:

According to the magnitude and flow rates G 1 - G 8, according to the nomogram, we find the diameters of the pipes, the coolant velocity and. The result is entered in table 3.1:

Table 3.1

plot number	Estimation	final settlement

Let's do the final calculation. We specify the hydraulic resistance in all sections of the network with the selected pipe diameters.

We determine the equivalent lengths of local resistances in the design sections according to the table "equivalent lengths of local resistances".

dP \u003d R * (l + l e) * 10 -3, kPa (18)

We determine the total hydraulic resistance for all sections of the design pipeline, which are compared with the pressure drop located in it:

The calculation is satisfactory if the hydraulic resistance does not exceed the available pressure drop and differs from it by no more than 25%. We translate the end result m. Art. to build a piezometric graph. All data is entered in table 3.

We will carry out the final calculation for each settlement area:

Plot 1:

The first section has the following local resistance with their equivalent lengths:

Gate valve: l e \u003d 3.36 m

Tee for dividing flows: l e \u003d 8.4 m

We calculate the total pressure loss in the sections according to the formula (18):

dP \u003d 390 * (5 + 3.36 + 8.4) * 10 -3 \u003d 6.7 kPa

Or m. st.:

H \u003d dP * 10 -3 / 9.81 \u003d 6.7 / 9.81 \u003d 0.7 m

Plot 2:

The second section has the following local resistances with their equivalent lengths:

U-shaped compensator: l e \u003d 19 m

dP \u003d 420 * (62.5 + 19 + 10.9) * 10 -3 \u003d 39 kPa

H= 39/9.81=4 m

Plot 3:

The third section has the following local resistances with their equivalent lengths:

Tee for dividing flows: l e \u003d 10.9 m

dP \u003d 360 * (32.5 + 10.9) * 10 -3 \u003d 15.9 kPa

H= 15.9/9.81=1.6 m

Plot 4:

The fourth section has the following local resistances with their equivalent lengths:

Branch: l e \u003d 3.62 m

Tee for dividing flows: l e \u003d 10.9 m

dP \u003d 340 * (39 + 3.62 + 10.9) * 10 -3 \u003d 18.4 kPa

H=18.4/9.81=1.9 m

Plot 5:

The fifth section has the following local resistances with their equivalent lengths:

U-shaped compensator: l e \u003d 12.5 m

Branch: l e \u003d 2.25 m

Tee for dividing flows: l e \u003d 6.6 m

dP \u003d 590 * (97 + 12.5 + 2.25 + 6.6) * 10 -3 \u003d 70 kPa

H= 70/9.81=7.2 m

Plot 6:

The sixth section has the following local resistances with their equivalent lengths:

U-shaped compensator: l e \u003d 9.8 m

Tee for dividing flows: l e \u003d 4.95 m

dP \u003d 340 * (119 + 9.8 + 4.95) * 10 -3 \u003d 45.9 kPa

H= 45.9/9.81=4.7 m

Plot 7:

The seventh section has the following local resistances with their equivalent lengths:

Two branches: l e \u003d 2 * 0.65 m

Tee for dividing flows: l e \u003d 1.3 m

dP \u003d 190 * (107.5 + 2 * 0.65 + 5.2 + 1.3) * 10 -3 \u003d 22.3 kPa

H= 22.3/9.81=2.3 m

Plot 8:

The eighth section has the following local resistances with their equivalent lengths:

Gate valve: l e \u003d 0.65 m

Branch: l e \u003d 0.65 m

dP \u003d 65 * (87.5 + 0.65 +.065) * 10 -3 \u003d 6.2 kPa

H= 6.2/9.81= 0.6 m

We determine the total hydraulic resistance and compare it with the available differential according to (17=9):

Let's calculate the difference in percentage:

? = ((270-224,4)/270)*100 = 17%

The calculation is satisfactory because hydraulic resistance does not exceed the available pressure drop, and differs from it by less than 25%.

Similarly, we calculate the branches and enter the result in table 3.2:

Table 3.2

plot number	Estimation	final settlement

Plot 22:

Available pressure at the subscriber:? H 22 \u003d 0.6 m

On the 22nd section, there are the following local resistances with their equivalent lengths:

Branch: l e \u003d 0.65 m

U-shaped compensator: l e \u003d 5.2 m

Gate valve: l e \u003d 0.65 m

dP \u003d 32 * (105 + 0.65 + 5.2 + 0.65) * 10 -3 \u003d 3.6 Pa

H= 3.6/9.81=0.4 m

Excess pressure in the branch: ?H 22 - ?H \u003d 0.6-0.4 \u003d 0.2 m

? = ((0,6-0,4)/0,6)*100 = 33,3%

Plot 23:

Available pressure at the subscriber: ?H 23 = ?H 8 +?H 7 = 0.6 + 2.3 = 2.9 m

On the 23rd section, there are the following local resistances with their equivalent lengths:

Branch: l e \u003d 1.65 m

Gate valve: l e \u003d 1.65 m

dP \u003d 230 * (117.5 + 1.65 + 1.65) * 10 -3 \u003d 27.8 kPa

H= 27.8/9.81=2.8 m

Excess pressure in the branch:? H 23 -? H \u003d 2.9-2.8 \u003d 0.1 m<25%

Plot 24:

Available pressure at the subscriber: ?H 24 = ?H 23 +?H 6 = 2.9 + 4.7 = 7.6 m

On the 24th section, there are the following local resistances with their equivalent lengths:

Branch: l e \u003d 1.65 m

Gate valve: l e \u003d 1.65 m

dP \u003d 480 * (141.5 + 1.65 + 1.65) * 10 -3 \u003d 69.5 kPa

H=74.1 /9.81=7.1 m

Excess pressure in the branch: ?H 24 - ?H \u003d 7.6-7.1 \u003d 0.5 m<25%

Plot 25:

Available pressure at the subscriber: ?H 25 = ?H 24 +?H 5 = 7.6 + 7.2 = 14.8 m

On the 25th section, there are the following local resistances with their equivalent lengths:

Branch: l e \u003d 2.25 m

Gate valve: l e \u003d 2.2 m

dP \u003d 580 * (164.5 + 2.25 + 2.2) * 10 -3 \u003d 98 kPa

H= 98/9.81=10 m

Excess pressure in the branch: ?H 25 - ?H \u003d 14.8-10 \u003d 4.8 m

? = ((14,8-10)/14,8)*100 = 32,4%

Because the difference in values is more than 25% and it is not possible to install pipes with a smaller diameter, it is necessary to install a throttle washer.

Plot 26:

Available pressure at the subscriber: ?H 26 = ?H 25 +?H 4 = 14.8 + 1.9 = 16.7 m

On the 26th section, there are the following local resistances with their equivalent lengths:

Branch: l e \u003d 0.65 m

Gate valve: l e \u003d 0.65 m

dP \u003d 120 * (31.5 + 0.65 + 0.65) * 10 -3 \u003d 3.9 kPa

H= 3.9/9.81=0.4 m

Excess pressure in the branch: ?H 26 - ?H \u003d 16.7-0.4 \u003d 16.3 m

? = ((16,7-0,4)/16,7)*100 = 97%

Because the difference in values is more than 25% and it is not possible to install pipes with a smaller diameter, it is necessary to install a throttle washer.

Plot 27:

Available head at the subscriber: ?H 27 = ?H 26 +?H 3 = 16.7 + 1.6 = 18.3 m

On the 27th section, there are the following local resistances with their equivalent lengths:

Withdrawal: l e \u003d 1 m

Gate valve: l e \u003d 1 m

dP \u003d 550 * (40 + 1 + 1) * 10 -3 \u003d 23.1 kPa

H= 23.1/9.81=2.4 m

Excess pressure in the branch: ?H 27 - ?H \u003d 18.3-2.4 \u003d 15.9 m

Reducing the diameter of the pipeline is not possible, so it is necessary to install a throttle washer.

I welcome you, dear and respected readers of the site "site". A necessary step in the design of heat supply systems for enterprises and residential areas is the hydraulic calculation of pipelines for water heating networks. It is necessary to solve the following tasks:

Determination of the inner diameter of the pipeline for each section of the heating network d V, mm. According to the diameters of the pipeline and their lengths, knowing their material and method of laying, it is possible to determine capital investments in heating networks.
Determination of pressure losses of network water or pressure losses of network water Δh, m; ΔР, MPa. These losses are the initial data for successive calculations of the head of network and make-up pumps in heat networks.

Hydraulic calculation of heat networks is also performed for existing operating heat networks, when the task is to calculate their actual throughput, i.e. when there is a diameter, length and you need to find the consumption of network water that will pass through these networks.

Hydraulic calculation of pipelines of heat networks is performed for the following modes of their operation:

A) for the design mode of operation of the heating network (max G O; G B; G DHW);

B) for summer mode, when only G DHW flows through the pipeline

C) for static mode, the network pumps are stopped at the heat supply source, and only make-up pumps are running.

D) for emergency operation, when an accident occurs in one or more sections, the diameter of the jumpers and reserve pipelines.

If heat networks work for a water open heat supply system, then it is also determined:

E) winter mode, when network water for the hot water supply system of buildings is taken from the return pipeline of the heating network.

E) transient mode, when network water for hot water supply of buildings is taken from the supply pipeline of the heating network.

In the hydraulic calculation of pipelines of heat networks, the following quantities must be known:

The maximum load on heating and ventilation and the average hourly load on the hot water supply: max Q O, max Q VENT, Q SR DHW.
Temperature chart of the heat supply system.
Temperature graph of network water, temperature of network water at the break point τ 01 NI, τ 02 NI.
The geometric length of each section of heating networks: L 1 , L 2 , L 3 ...... L N .
The condition of the inner surface of the pipeline in each section of the heating network (the amount of corrosion and scale deposits). k E - equivalent roughness of the pipeline.
The number, type and arrangement of local resistances that are available in each section of the heating network (all gate valves, valves, turns, tees, compensators).
Physical properties of water p V, I V.

How the hydraulic calculation of pipelines of heat networks is performed will be considered using the example of a radial heat network serving 3 heat consumers.

Schematic diagram of a radial heating network that transports thermal energy for 3 heat consumers

1 - heat consumers (residential areas)

2 - sections of the heating network

3 - source of heat supply

Hydraulic calculation of the designed heat networks is performed in the following sequence:

According to the schematic diagram of heat networks, the consumer is determined, which is the most distant from the source of heat supply. The heat network laid from the source of heat supply to the most remote consumer is called the main highway (main highway), in the figure L 1 + L 2 + L 3. Sections 1.1 and 2.1 are branches from the main line (branch).
The estimated direction of movement of network water from the source of heat supply to the most remote consumer is outlined.
The calculated direction of movement of network water is divided into separate sections, on each of which the inner diameter of the pipeline and the flow rate of network water must remain constant.
The estimated consumption of network water is determined in the sections of the heating network to which consumers are connected (2.1; 3; 3.1):

G SUM UCH \u003d G O R + G B R + k 3 * G G SR

G О Р \u003d Q О Р / С В * (τ 01 Р - τ 02 Р) - maximum heating consumption

k 3 - coefficient taking into account the share of consumption of network water supplied to hot water supply

G V R \u003d Q V R / S V * (τ 01 R - τ V2 R) - maximum flow for ventilation

G G SR \u003d Q GW SR / S V * (τ 01 NI - τ G2 NI) - average consumption for hot water supply

k 3 \u003d f (type of heat supply system, heat load of the consumer).

Values k 3 depending on the type of heat supply system and heat loads of connection of heat consumers

According to the reference data, the physical properties of network water in the supply and return pipelines of the heating network are determined:

P IN POD = f (τ 01) V IN POD = f (τ 01)

P IN OBR = f (τ 02) V IN OBR = f (τ 02)

The average values of network water density and its velocity are determined:

P IN SR \u003d (P IN LOD + P IN OBR) / 2; (kg / m 3)

V IN SR \u003d (V IN UNDER + V IN OBR) / 2; (m 2 /s)

Hydraulic calculation of pipelines of each section of heating networks is carried out.

7.1. They are set by the speed of movement of network water in the pipeline: V B \u003d 0.5-3 m / s. The lower limit V B is due to the fact that at lower speeds, the deposition of suspended particles on the walls of the pipeline increases, and also at lower speeds, the circulation of water stops and the pipeline may freeze.

V B \u003d 0.5-3 m / s. - the greater value of the velocity in the pipeline is due to the fact that with an increase in velocity of more than 3.5 m / s, a hydraulic shock may occur in the pipeline (for example, when valves are suddenly closed, or when the pipeline is turned in a section of the heating network).

7.2. The internal diameter of the pipeline is calculated:

d V \u003d sqrt [(G SUM PCH * 4) / (p V SR * V V * π)] (m)

7.3. According to the reference data, the closest values of the inner diameter are taken, which correspond to GOST d V GOST, mm.

7.4. The actual speed of water movement in the pipeline is specified:

V V F \u003d (4 * G SUM UCH) / [π * p V SR * (d V GOST) 2]

7.5. The mode and zone of flow of network water in the pipeline is determined, for this a dimensionless parameter is calculated (Reynolds criterion)

Re = (V V F * d V GOST) / V V F

7.6. Re PR I and Re PR II are calculated.

Re PR I = 10 * d V GOST / k E

Re PR II \u003d 568 * d V GOST / k E

For various types of pipelines and various degrees of wear of the pipeline, k E lies within. 0.01 - if the pipeline is new. When the type of pipeline and the degree of their wear are unknown according to SNiP ”Heat Networks” 41-02-2003. The value of k E is recommended to be chosen equal to 0.5 mm.

7.7. The coefficient of hydraulic friction in the pipeline is calculated:

— if the criterion Re< 2320, то используется формула: λ ТР = 64 / Re.

— if the Re criterion lies within (2320; Re PR I ], then the Blasius formula is used:

λ TP =0.11*(68/Re) 0.25

These two formulas must be used for laminar water flow.

— if the Reynolds criterion lies within (Re PR I< Re < =Re ПР II), то используется формула Альтшуля.

λ TP \u003d 0.11 * (68 / Re + k E / d V GOST) 0.25

This formula is used in the transitional movement of network water.

- if Re > Re PR II, then the Shifrinson formula is used:

λ TP \u003d 0.11 * (k E / d V GOST) 0.25

Δh TP \u003d λ TP * (L * (V V F) 2) / (d V GOST * 2 * g) (m)

ΔP TR = p V SR *g* Δh TR = λ TR * / (d V GOST *2) = R L *L (Pa)

R L \u003d [λ TP * r V SR * (V V F) 2] / (2 * d V GOST) (Pa / m)

R L - specific linear pressure drop

7.9. Pressure losses or pressure losses in local resistances in the pipeline section are calculated:

Δh M.S. = Σ£ M.S. *[(V V F) 2 /(2*g)]

Δp M.S. = p B SR *g* Δh M.S. = Σ£ M.S. *[((V V F) 2 * R V SR)/2]

Σ£ M.S. - the sum of the local resistance coefficients installed on the pipeline. For each type of local resistance £ M.S. taken from reference data.

7.10. The total head loss or total pressure loss in the pipeline section is determined:

h = Δh TR + Δh M.S.

Δp = Δp TR + Δp M.S. = p B SR *g* Δh TP + p B SR *g*Δh M.S.

According to this method, calculations are carried out for each section of the heating network and all values are summarized in a table.

The main results of the hydraulic calculation of pipelines of sections of the water heating network

For indicative calculations of sections of water heating networks when determining R L, Δr TP, Δr M.S. the following expressions are allowed:

R L \u003d / [p V SR * (d V GOST) 5.25] (Pa / m)

R L \u003d / (d V GOST) 5.25 (Pa / m)

A R \u003d 0.0894 * K E 0.25 - an empirical coefficient that is used for an approximate hydraulic calculation in water heating networks

A R B \u003d (0.0894 * K E 0.25) / r B SR \u003d A R / r B SR

These coefficients were derived by Sokolov E.Ya. and are given in the textbook "Heat supply and heat networks".

Given these empirical coefficients, head and pressure losses are defined as:

Δp TR \u003d R L * L \u003d / [p V SR * (d V GOST) 5.25] \u003d

= / (d In GOST) 5.25

Δh TP = Δp TP / (p B SR *g) = (R L *L) / (p B SR *g) =

\u003d / (p V SR) 2 * (d V GOST) 5.25 \u003d

\u003d / p V SR * (d V GOST) 5.25 * g

Also taking into account A R and A R B; Δr M.S. and Δh M.S. will be written like this:

Δr M.S. \u003d R L * L E M \u003d / p V SR * (d V GOST) 5.25 \u003d

\u003d / (d In GOST) 5.25

Δh M.S. = Δp M.S. / (p B SR *g) \u003d (R L *L E M) / (r B SR *g) \u003d

\u003d / p V SR * (d V GOST) 5.25 \u003d

\u003d / (d In GOST) 5.25 * g

L E \u003d Σ (£ M. C. * d V GOST) / λ TR

The peculiarity of the equivalent length is that the head loss of local resistances is represented as a head drop in a straight section with the same inner diameter, and this length is called equivalent.

Total pressure and head losses are calculated as:

Δh = Δh TR + Δh M.S. \u003d [(R L *L) / (p B SR *g)] + [(R L *L E) / (r B SR *g)] =

\u003d * (L + L E) \u003d * (1 + a M. S.)

Δr \u003d Δr TP + Δr M. S. \u003d R L * L + R L * L E \u003d R L (L + L E) \u003d R L * (1 + a M. S.)

and M.S. - coefficient of local losses in the section of the water heating network.

In the absence of accurate data on the number, type and arrangement of local resistances, the value of a M.S. can be taken from 0.3 to 0.5.

I hope that now it has become clear to everyone how to correctly perform the hydraulic calculation of pipelines and you yourself will be able to perform the hydraulic calculation of heat networks. Tell us in the comments what you think, can you calculate the hydraulic calculation of pipelines in excel, or do you use an online calculator for the hydraulic calculation of pipelines or use a nomogram for the hydraulic calculation of pipelines?

Energy is the main product that man has learned to create. It is necessary both for household activity and for industrial enterprises. In this article we will talk about the norms and rules for the design and construction of outdoor heating networks.

What is a heating network

This is a set of pipelines and devices that reproduce, transport, store, regulate and provide all food items with heat through hot water or steam. From the energy source, it enters the transmission lines, and then distributed throughout the premises.

What is included in the design:

pipes that are pre-treated against corrosion, and are also insulated - the sheathing may not be all the way, but only in the area that is located on the street;
compensators - devices that are responsible for the movement, temperature deformations, vibrations and displacements of the substance inside the pipeline;
mounting system - depending on the type of installation, there are different options, but in any case, support mechanisms are needed;
trenches for laying - concrete gutters and tunnels are equipped if the laying takes place on the ground;
shut-off or control valves - temporarily stops the pressure or helps to reduce it, block the flow.

Also, the building heat supply project may contain additional equipment inside the engineering heating system and hot water supply. So the design is divided into two parts - external and internal heating system. The first can come from the central main pipelines, or maybe from a heating unit, a boiler room. There are also systems inside the premises that regulate the amount of heat in individual rooms, workshops - if the question concerns industrial enterprises.

Classification of heating systems according to the main features and basic design methods

There are several criteria by which the system can differ. This is the way they are placed, and the purpose, and the area of \u200b\u200bheat supply, their power, as well as many additional functions. At the time of designing the heat supply system, the designer will definitely find out from the customer how much energy the line should transport daily, how many outlets to have, what operating conditions will be - climatic, meteorological, and also how not to spoil the urban development.

According to these data, one of the gasket types can be selected. Let's look at classifications.

By installation type

Distinguish:

Air, they are above ground.

This solution is not used very often due to the difficulties of installation, maintenance, repair, and also because of the unsightly appearance of such bridges. Unfortunately, the project usually does not include decorative elements. This is due to the fact that boxes and other masking structures often prevent access to pipes, as well as prevent them from seeing a problem, such as a leak or crack, in a timely manner.

The decision to design air heating systems is made after engineering surveys to examine areas with seismic activity, as well as a high level of groundwater. In such cases, it is not possible to dig trenches and carry out ground laying, as this can be unproductive - natural conditions can damage the casing, moisture will affect accelerated corrosion, and soil mobility will lead to pipe breaks.

Another recommendation for carrying out above-ground structures is dense residential development, when it is simply not possible to dig holes, or in the case when one or more lines of existing communications already exist at this place. When carrying out land works in this case, there is a high risk of damaging the engineering systems of the city.

Air heating systems are mounted on metal supports and poles, where they are attached to hoops.

Underground.

They, respectively, are laid underground or on it. There are two options for the design of the heat supply system - when laying is carried out in a channel way and without a channel.

In the first case, a concrete channel or tunnel is laid. Concrete is reinforced, pre-prepared rings can be used. This protects pipes, windings, and also facilitates inspection and maintenance, as the entire system is kept clean and dry. Protection occurs simultaneously from moisture, groundwater and flooding, as well as from corrosion. Including such precautionary measures help to prevent mechanical influence on the line. Channels can be monolithic concrete pouring or prefabricated, their second name is tray.

The channelless method is less preferable, but it takes much less time, labor and material resources. This is a cost-effective way, but the pipes themselves are not used ordinary, but special ones - with or without a protective sheath, but then the material must be made of polyvinyl chloride or with its addition. The process of repair and installation becomes more difficult if it is planned to reconstruct the network, expand the heating network, since it will be necessary to perform land work again.

By type of coolant

Two elements can be transported:

Hot water.

It transmits thermal energy and can simultaneously serve for the purpose of water supply. The peculiarity is that such pipelines do not fit alone, even the main ones. They must be carried out in an amount that is a multiple of two. Usually these are two-pipe and four-pipe systems. This requirement is due to the fact that not only the supply of liquid is needed, but also its removal. Usually the cold flow (return) is returned to the heat point. Secondary treatment takes place in the boiler room - filtration, and then water heating.

These are more difficult in designing a heating network - an example of their typical design contains the conditions for protecting pipes from super-hot temperatures. The fact is that the vapor carrier is much hotter than the liquid. This gives increased efficiency, but contributes to the deformation of the pipeline, its walls. This can be prevented by using quality building materials and regularly monitoring for possible changes in head pressure.

Another phenomenon is also dangerous - the formation of condensate on the walls. It is necessary to make a winding that will remove moisture.

Danger also lurks in connection with possible injuries during maintenance and breakthrough. The steam burn is very strong, and since the substance is transmitted under pressure, it can lead to significant damage to the skin.

According to design schemes

Also, this classification can be called - by value. There are the following objects:

Trunk.

They have only one function - transportation over long distances. Usually this is the transfer of energy from a source, a boiler room, to distribution nodes. There may be heat points that are engaged in branching routes. The mains have powerful indicators - the temperature of the contents is up to 150 degrees, the diameter of the pipes is up to 102 cm.

Distribution.

These are less significant lines, the purpose of which is to deliver hot water or steam to residential buildings and industrial enterprises. According to the cross section, they can be different, it is chosen depending on the permeability of energy per day. For apartment buildings and factories, maximum values \u200b\u200bare usually used - they do not exceed 52.5 cm in diameter. While for private properties, residents usually bring a small pipeline that can satisfy their needs for warmth. The temperature regime usually does not exceed 110 degrees.

quarterly.

This is a subtype of distribution. They have the same technical characteristics, but serve the purpose of distributing the substance among the buildings of one residential area, block.

Branches.

They are designed to connect the highway and the heat point.

By heat source

Distinguish:

Centralized.

The starting point of heat dissipation is a large heating station that feeds the entire city or a large part of it. These can be thermal power plants, large boiler houses, nuclear power plants.

Decentralized.

They are engaged in transportation from small sources - autonomous heating stations that can supply only a small residential area, one apartment building, a specific industrial production. Autonomous power sources, as a rule, do not need sections of highways, since they are located next to the object, structure.

Stages of drawing up a heating network project

Collection of initial data.

The customer provides the terms of reference to the designer and independently or through third-party organizations draws up a list of information that will be needed in the work. This is the amount of heat energy that is required per year and daily, the designation of power points, as well as operating conditions. There may also be preferences for the maximum cost of all work and the materials used. First of all, the order should indicate what the heating network is for - living quarters, production.

Engineering survey.

The work is carried out both on the ground and in laboratories. The engineer then completes the reports. The system of checks includes soil, soil properties, groundwater level, as well as climatic and meteorological conditions, and the seismic characteristics of the area. For work and reporting, you will need a bunch of ++. These programs will ensure the automation of the entire process, as well as compliance with all norms and standards.

Engineering system design.

At this stage, drawings, diagrams of individual nodes are drawn up, calculations are performed. A real designer always uses high-quality software, for example, . The software is designed to work with engineering networks. With its help, it is convenient to trace, create wells, indicate line intersections, as well as mark the pipeline section and make additional marks.

Regulatory documents that guide the designer - SNiP 41-02-2003 "Heat networks" and SNiP 41-03-2003 "Thermal insulation of equipment and devices".

At the same stage, construction and design documentation is drawn up. To comply with all the rules of GOST, SP and SNiP, you must use the program or. They automate the process of filling out paperwork according to legal standards.

Project approval.

First, the layout is offered to the customer. At this point, it is convenient to use the 3D visualization function. The volumetric model of the pipeline is clearer, it shows all the nodes that are not visible in the drawing to a person who is not familiar with the rules of drawing. And for professionals, a three-dimensional layout is necessary to make adjustments, to provide for unwanted intersections. The program has such a function. It is convenient to compile all working and project documentation, draw and perform basic calculations using the built-in calculator.

Then the approval must pass in a number of instances of the city government, as well as undergo an expert assessment by an independent representative. It is convenient to use the electronic document management function. This is especially true when the customer and contractor are in different cities. All ZVSOFT products interact with common engineering, text and graphic formats, so the design team can use this software to process data received from different sources.

The composition of a typical heat network project and an example of heating mains

The main elements of the pipeline are mainly produced by manufacturers in finished form, so it remains only to correctly position and mount them.

Consider the content of the details on the example of a classical system:

Pipes. We discussed their diameter above in connection with the typology of structures. And the length has standard parameters - 6 and 12 meters. You can order individual cutting at the factory, but it will cost much more.
It is important to use new products. It is better to use those that are produced immediately with insulation.
Connection elements. These are knees at an angle of 90, 75, 60, 45 degrees. The same group includes: bends, tees, transitions and caps on the end of the pipe.
Stop valve. Its purpose is to block water. Locks can be in special boxes.
Compensator. It is required on all sections of the turn of the track. They relieve pressure-related expansion and deformation of the pipeline.

Make a quality heating network project together with software products from ZVSOFT.