The bunker of a fraction of a copper tgm 84 principle of work. Influence of steam load on the heat fluxes of the torch in the boiler furnace. Geometric characteristics of superheaters

Compiled by: M.V. KALMYKOV UDC 621.1 Design and operation of the TGM-84 boiler: Method. ukaz. / Samar. state tech. un-t; Comp. M.V. Kalmykov. Samara, 2006. 12 p. The main technical characteristics, layout and description of the design of the TGM-84 boiler and the principle of its operation are considered. The drawings of the layout of the boiler unit with auxiliary equipment, the general view of the boiler and its components are given. A diagram of the steam-water path of the boiler and a description of its operation are presented. Methodical instructions are intended for students of specialty 140101 "Thermal power plants". Il. 4. Bibliography: 3 titles. Printed by decision of the editorial and publishing council of SamSTU 0 MAIN CHARACTERISTICS OF THE BOILER UNIT Boiler units TGM-84 are designed to produce steam high pressure when burning gaseous fuel or fuel oil and are designed for the following parameters: behind the main steam valve ……………. Superheated steam temperature ………………………………………. Feed water temperature ……………………………………… Hot air temperature a) during fuel oil combustion …………………………………………. b) when burning gas ……………………………………………. 420 t/h 155 ata 140 ata 550 °C 230 °C 268 °C 238 °C It consists of a combustion chamber, which is an ascending gas duct and a descending convective shaft (Fig. 1). The combustion chamber is divided by a two-light screen. The lower part of each side screen passes into a slightly inclined hearth screen, the lower collectors of which are attached to the collectors of the two-light screen and move together with thermal deformations during the firing and shutdown of the boiler. The presence of a two-light screen provides more intensive cooling of flue gases. Accordingly, the thermal stress of the furnace volume of this boiler was chosen to be significantly higher than in pulverized coal units, but lower than in other standard sizes of gas-oil boilers. This facilitated the working conditions of the pipes of the two-light screen, which perceive the largest number heat. In the upper part of the furnace and in the rotary chamber there is a semi-radiation screen superheater. The convective shaft houses a horizontal convective superheater and a water economizer. Behind the water economizer there is a chamber with shot cleaning receiving bins. Two regenerative air heaters of the RVP-54 type, connected in parallel, are installed after the convective shaft. The boiler is equipped with two VDN-26-11 blowers and two D-21 exhaust fans. The boiler was repeatedly reconstructed, as a result of which the TGM-84A model appeared, and then TGM-84B. In particular, unified screens were introduced and a more uniform distribution of steam between the pipes was achieved. The transverse pitch of the pipes in the horizontal stacks of the convective part of the steam superheater was increased, thereby reducing the likelihood of its contamination with black oil. 2 0 R and s. 1. Longitudinal and transverse sections of the gas-oil boiler TGM-84: 1 – combustion chamber; 2 - burners; 3 - drum; 4 - screens; 5 - convective superheater; 6- condensing unit; 7 – economizer; 11 - shot catcher; 12 - remote separation cyclone Boilers of the first modification TGM-84 were equipped with 18 oil-gas burners placed in three rows on the front wall of the combustion chamber. Currently, either four or six burners of higher productivity are installed, which simplifies the maintenance and repair of boilers. BURNER DEVICES The combustion chamber is equipped with 6 oil-gas burners installed in two tiers (in the form of 2 triangles in a row, tops up, on the front wall). The burners of the lower tier are set at 7200 mm, the upper tier at 10200 mm. The burners are designed for separate combustion of gas and fuel oil, vortex, single-flow with central gas distribution. The extreme burners of the lower tier are turned towards the axis of the semi-furnace by 12 degrees. To improve the mixing of fuel with air, the burners have guide vanes, passing through which the air is twisted. Oil nozzles with mechanical spray are installed along the axis of the burners on the boilers, the length of the oil nozzle barrel is 2700 mm. The design of the furnace and the layout of the burners must ensure a stable combustion process, its control, and also exclude the possibility of the formation of poorly ventilated areas. Gas burners must operate stably, without separation and flashover of the flame in the range of regulation of the boiler heat load. Applied on boilers gas-burners must be certified and have manufacturer's passports. FURNACE CHAMBER The prismatic chamber is divided by a two-light screen into two semi-furnaces. The volume of the combustion chamber is 1557 m3, the heat stress of the combustion volume is 177000 kcal/m3 hour. The side and rear walls of the chamber are shielded by evaporator tubes 60×6 mm in diameter with a pitch of 64 mm. The side screens in the lower part have slopes towards the middle of the firebox with a slope of 15 degrees to the horizontal and form a hearth. To avoid stratification of the steam-water mixture in pipes slightly inclined to the horizontal, the sections of the side screens forming the hearth are covered with fireclay bricks and chromite mass. The screen system is suspended from the metal structures of the ceiling with the help of rods and has the ability to freely fall down during thermal expansion. The pipes of the evaporation screens are welded together with a D-10 mm rod with a height interval of 4-5 mm. To improve the aerodynamics of the upper part of the combustion chamber and protect the rear screen chambers from radiation, the pipes of the rear screen in the upper part form a ledge into the furnace with an overhang of 1.4 m. The ledge is formed by 70% of the rear screen pipes. 3 In order to reduce the effect of uneven heating on circulation, all screens are sectioned. The two-light and two side screens have three circulation circuits each, the rear screen has six. Boilers TGM-84 operate on a two-stage evaporation scheme. The first stage of evaporation (clean compartment) includes a drum, panels of the rear, two-light screens, 1st and 2nd from the front of the side screen panels. The second evaporation stage (salt compartment) includes 4 remote cyclones (two on each side) and third panels of side screens from the front. To the six lower chambers of the rear screen, water from the drum is supplied through 18 drain pipes, three to each collector. Each of the 6 panels includes 35 screen tubes. The upper ends of the pipes are connected to the chambers, from which the steam-water mixture enters the drum through 18 pipes. The two-light screen has windows formed by piping for pressure equalization in semi-furnaces. To the three lower chambers of the double-height screen, water from the drum enters through 12 culvert pipes (4 pipes for each collector). The end panels have 32 screen tubes each, the middle one has 29 tubes. The upper ends of the pipes are connected to three upper chambers, from which the steam-water mixture is directed to the drum through 18 pipes. Water flows from the drum through 8 drain pipes to the four front lower collectors of the side screens. Each of these panels contains 31 screen tubes. The upper ends of the screen pipes are connected to 4 chambers, from which the steam-water mixture enters the drum through 12 pipes. The lower chambers of the salt compartments are fed from 4 remote cyclones through 4 drain pipes (one pipe from each cyclone). Salt compartment panels contain 31 screen pipes. The upper ends of the screen pipes are connected to the chambers, from which the steam-water mixture enters 4 remote cyclones through 8 pipes. DRUM AND SEPARATION DEVICE The drum has an internal diameter of 1.8 m, a length of 18 m. All drums are made of sheet steel 16 GNM (manganese-nickel-molybdenum steel), wall thickness 115 mm. Drum weight about 96600 kg. The boiler drum is designed to create a natural circulation of water in the boiler, clean and separate the steam produced in the screen pipes. Separation of the steam-water mixture of the 1st stage of evaporation is organized in the drum (separation of the 2nd stage of evaporation is carried out on boilers in 4 remote cyclones), washing of all steam is carried out with feed water, followed by trapping of moisture from the steam. The entire drum is a clean compartment. The steam-water mixture from the upper collectors (except for the collectors of salt compartments) enters the drum from two sides and enters a special distribution box, from which it is sent to cyclones, where the primary separation of steam from water takes place. In the drums of the boilers, 92 cyclones are installed - 46 left and 46 right. 4 Horizontal plate separators are installed at the steam outlet from the cyclones. The steam, having passed them, enters the bubbling-washing device. Here, under the washing device of the clean compartment, steam is supplied from external cyclones, inside which the separation of the steam-water mixture is also organized. The steam, having passed the bubbling-flushing device, enters the perforated sheet, where the steam is separated and the flow is equalized simultaneously. Having passed the perforated sheet, the steam is discharged through 32 steam outlet pipes to the inlet chambers of the wall-mounted superheater and 8 pipes to the condensate unit. Rice. 2. Two-stage evaporation scheme with remote cyclones: 1 – drum; 2 - remote cyclone; 3 - lower collector of the circulation circuit; 4 - steam generating pipes; 5 - downpipes; 6 - supply of feed water; 7 – purge water outlet; 8 - water bypass pipe from the drum to the cyclone; 9 - steam bypass pipe from the cyclone to the drum; 10 - steam outlet pipe from the unit About 50% of the feed water is supplied to the bubbling-flushing device, and the rest of it is drained through the distribution manifold into the drum under the water level. The average water level in the drum is 200 mm below its geometric axis. Permissible level fluctuations in the drum 75 mm. To equalize the salt content in the salt compartments of the boilers, two culverts were transferred, so the right cyclone feeds the lower left collector of the salt compartment, and the left one feeds the right one. 5 DESIGN OF THE STEAM SUPERHEATER The heating surfaces of the superheater are located in the combustion chamber, the horizontal flue and the drop shaft. The scheme of the superheater is double-flow with multiple mixing and transfer of steam across the width of the boiler, which allows you to equalize the thermal distribution of individual coils. According to the nature of the perception of heat, the superheater is conditionally divided into two parts: radiative and convective. The radiant part includes a wall-mounted superheater (SSH), the first row of screens (SHR) and a part of the ceiling superheater (SHS), shielding the ceiling of the combustion chamber. To the convective - the second row of screens, a part of the ceiling superheater and a convective superheater (KPP). Radiation wall-mounted superheater NPP pipes shield the front wall of the combustion chamber. NPP consists of six panels, two of them have 48 pipes each, and the rest have 49 pipes, the pitch between the pipes is 46 mm. Each panel has 22 down pipes, the rest are up. The inlet and outlet manifolds are located in the non-heated area above the combustion chamber, the intermediate manifolds are located in the non-heated area below the combustion chamber. The upper chambers are suspended from the metal structures of the ceiling with the help of rods. The pipes are fastened in 4 tiers in height and allow vertical movement of the panels. Ceiling superheater Ceiling superheater is located above the furnace and horizontal flue, consists of 394 pipes placed with 35 mm pitch and connected by inlet and outlet collectors. Screen superheater The screen superheater consists of two rows of vertical screens (30 screens in each row) located in the upper part of the combustion chamber and the rotary flue. Step between screens 455 mm. The screen consists of 23 coils of the same length and two manifolds (inlet and outlet) installed horizontally in an unheated area. Convective superheater Horizontal type convective superheater consists of left and right parts located in the downcomer flue above the water economizer. Each side, in turn, is divided into two straight-through steps. 6 STEAM PATH OF THE BOILER Saturated steam from the boiler drum through 12 steam bypass pipes enters the upper collectors of the NPP, from which it moves down through the middle pipes of 6 panels and enters 6 lower collectors, after which it rises up through the outer pipes of 6 panels to the upper collectors, of which 12 unheated pipes are directed to the inlet collectors of the ceiling superheater. Further, the steam moves along the entire width of the boiler along the ceiling pipes and enters the outlet collectors of the superheater located at rear wall convective flue. From these collectors, the steam is divided into two streams and directed to the chambers of the desuperheaters of the 1st stage, and then to the chambers of the outer screens (7 left and 7 right), after passing through which both steam flows enter the intermediate desuperheaters of the 2nd stage, left and right. In desuperheaters of stages I and II, steam is transferred from the left side to the right side and, vice versa, in order to reduce the thermal imbalance caused by gas misalignment. After leaving the intermediate desuperheaters of the second injection, the steam enters the collectors of the middle screens (8 left and 8 right), passing through which it is directed to the inlet chambers of the checkpoint. Stage III desuperheaters are installed between the upper and lower parts of the gearbox. The superheated steam is then sent to the turbines through a steam pipeline. Rice. 3. Scheme of the boiler superheater: 1 - boiler drum; 2 - radiation two-way radiation tube panel (the upper collectors are conditionally shown on the left, and the lower collectors on the right); 3 - ceiling panel; 4 - injection desuperheater; 5 – place of water injection into steam; 6 - extreme screens; 7 - medium screens; 8 - convective packets; 9 – steam outlet from the boiler 7 CONDENSATE UNIT AND INJECTION DEPOSIT COOLERS To obtain its own condensate, the boiler is equipped with 2 condensate units (one on each side) located on the ceiling of the boiler above the convective part. They consist of 2 distribution manifolds, 4 condensers and a condensate collector. Each capacitor consists of a chamber D426×36 mm. The cooling surfaces of the condensers are formed by pipes welded to the tube plate, which is divided into two parts and forms a water outlet and a water inlet chamber. Saturated steam from the boiler drum is sent through 8 pipes to four distribution manifolds. From each collector, steam is diverted to two condensers by pipes of 6 pipes to each condenser. Condensation of saturated steam coming from the boiler drum is carried out by cooling it with feed water. Feed water after the suspension system is supplied to the water supply chamber, passes through the tubes of the condensers and exits to the drainage chamber and further to the water economizer. The saturated steam coming from the drum fills the steam space between the pipes, comes into contact with them and condenses. The resulting condensate through 3 pipes from each condenser enters two collectors, from there it is fed through the regulators to the desuperheaters I, II, III of the left and right injections. The injection of condensate occurs due to the pressure formed from the difference in the Venturi pipe and the pressure drop in the steam path of the superheater from the drum to the injection site. Condensate is injected into the cavity of the Venturi pipe through 24 holes with a diameter of 6 mm, located around the circumference at the narrow point of the pipe. The Venturi pipe at full load on the boiler reduces the steam pressure by increasing its speed at the injection site by 4 kgf/cm2. The maximum capacity of one condenser at 100% load and design parameters of steam and feed water is 17.1 t/h. WATER ECONOMIZER Steel serpentine water economizer consists of 2 parts, located respectively in the left and right parts of the drop shaft. Each part of the economizer consists of 4 blocks: lower, 2 middle and upper. Openings are made between the blocks. The water economizer consists of 110 coil packs arranged parallel to the boiler front. The coils in the blocks are staggered with a pitch of 30 mm and 80 mm. The middle and upper blocks are installed on beams located in the flue. To protect against the gas environment, these beams are covered with insulation, protected by metal sheets 3 mm thick from the impact of the shot blasting machine. The lower blocks are suspended from the beams with the help of racks. Racks allow the possibility of removing the package of coils during repair. 8 The inlet and outlet chambers of the water economizer are located outside the gas ducts and are attached to the boiler frame with brackets. The water economizer beams are cooled (the temperature of the beams during kindling and during operation should not exceed 250 °C) by supplying cold air to them from the pressure of the blower fans, with air discharge into the suction boxes of the blower fans. AIR HEATER Two regenerative air heaters RVP-54 are installed in the boiler room. The RVP-54 regenerative air heater is a counterflow heat exchanger consisting of a rotating rotor enclosed inside a fixed housing (Fig. 4). The rotor consists of a shell with a diameter of 5590 mm and a height of 2250 mm, made of sheet steel 10 mm thick and a hub with a diameter of 600 mm, as well as radial ribs connecting the hub with the shell, dividing the rotor into 24 sectors. Each sector is divided by vertical sheets into P and s. Fig. 4. Structural scheme of the regenerative air heater: 1 – duct; 2 - drum; 3 - body; 4 - stuffing; 5 - shaft; 6 - bearing; 7 - seal; 8 - electric motor three parts. Sections of heating sheets are laid in them. The height of the sections are installed in two rows. The top row is the hot part of the rotor, made of spacer and corrugated sheets, 0.7 mm thick. The lower row of sections is the cold part of the rotor and is made of spacer straight sheets, 1.2 mm thick. The cold end packing is more susceptible to corrosion and can be easily replaced. A hollow shaft passes inside the rotor hub, having a flange in the lower part, on which the rotor rests, the hub is attached to the flange with studs. RVP has two covers - upper and lower, sealing plates are installed on them. 9 The heat exchange process is carried out by heating the rotor packing in the gas flow and cooling it in the air flow. Sequential movement of the heated packing from the gas flow to the air flow is carried out due to the rotation of the rotor with a frequency of 2 revolutions per minute. At each moment of time, out of 24 sectors of the rotor, 13 sectors are included in the gas path, 9 sectors - in the air path, two sectors are switched off from work and are covered by sealing plates. The air heater uses the counterflow principle: air is introduced from the outlet side and exhausted from the gas inlet side. The air heater is designed for air heating from 30 to 280 °С while cooling gases from 331 °С to 151 °С when operating on fuel oil. The advantage of regenerative air heaters is their compactness and low weight, the main disadvantage is a significant overflow of air from the air side to the gas side (standard air suction is 0.2–0.25). BOILER FRAME The boiler frame consists of steel columns connected by horizontal beams, trusses and braces, and serves to absorb loads from the weight of the drum, all heating surfaces, condensate unit, lining, insulation and maintenance platforms. The frame of the boiler is made welded from shaped rolled metal and sheet steel. The frame columns are attached to the underground reinforced concrete foundation of the boiler, the base (shoe) of the columns is poured with concrete. LAYING The lining of the combustion chamber consists of refractory concrete, covelite slabs and sealing magnesia plaster. The lining thickness is 260 mm. It is installed in the form of shields that are attached to the boiler frame. The lining of the ceiling consists of panels, 280 mm thick, freely lying on the pipes of the superheater. The structure of the panels: a layer of refractory concrete 50 mm thick, a layer of thermally insulating concrete 85 mm thick, three layers of covelite boards, a total thickness of 125 mm and a layer of sealing magnesia coating, 20 mm thick, applied on metal mesh. The lining of the reversing chamber and the convection shaft are mounted on shields, which, in turn, are attached to the boiler frame. The total thickness of the lining of the reversing chamber is 380 mm: refractory concrete - 80 mm, thermally insulating concrete - 135 mm and four layers of covelite slabs 40 mm each. The lining of the convective superheater consists of one layer of thermally insulating concrete 155 mm thick, a layer of refractory concrete - 80 mm and four layers of covelite plates - 165 mm. Between the plates there is a layer of sovelite mastic with a thickness of 2÷2.5 mm. The lining of the water economizer, 260 mm thick, consists of refractory and thermally insulating concrete and three layers of covelite slabs. SAFETY PRECAUTIONS Operation boiler units must be carried out in accordance with the current "Rules for the Design and Safe Operation of Steam and Hot Water Boilers", approved by Rostekhnadzor and " technical requirements on the Explosion Safety of Boiler Plants Running on Fuel Oil and Natural Gas”, as well as the current “Safety Rules for Maintenance of Thermal Power Equipment of Power Plants”. Bibliographic list 1. Operation manual for the TGM-84 power boiler at the TPP VAZ. 2. Meiklyar M.V. Modern boiler units TKZ. M.: Energy, 1978. 3. A.P. Kovalev, N.S. Leleev, T.V. Vilensky. Steam generators: Textbook for universities. M.: Energoatomizdat, 1985. 11 Design and operation of the TGM-84 boiler Compiled by Maksim Vitalievich KALMYKOV Editor N.V. Versh i nina Technical editor G.N. Shan'kov Signed for publication on 20.06.06. Format 60×84 1/12. Offset paper. Offset printing. R.l. 1.39. Condition.cr.-ott. 1.39. Uch.-ed. l. 1.25 Circulation 100. P. - 171. _________________________________________________________________________________________________ State educational institution higher professional education "Samara State Technical University" 432100. Samara, st. Molodogvardeyskaya, 244. Main building 12

The typical energy characteristic of the TGM-96B boiler reflects the technically achievable efficiency of the boiler. A typical energy characteristic can serve as the basis for compiling the standard characteristics of TGM-96B boilers when burning fuel oil.

MINISTRY OF ENERGY AND ELECTRIFICATION OF THE USSR

MAIN TECHNICAL DEPARTMENT FOR OPERATION
ENERGY SYSTEMS

TYPICAL ENERGY DATA
OF THE TGM-96B BOILER FOR FUEL FUEL COMBUSTION

Moscow 1981

This Typical Energy Characteristic was developed by Soyuztekhenergo (engineer G.I. GUTSALO)

The typical energy characteristic of the TGM-96B boiler was compiled on the basis of thermal tests conducted by Soyuztekhenergo at the Riga CHPP-2 and Sredaztekhenergo at the CHPP-GAZ, and reflects the technically achievable efficiency of the boiler.

A typical energy characteristic can serve as the basis for compiling the standard characteristics of TGM-96B boilers when burning fuel oil.



Appendix

. BRIEF DESCRIPTION OF THE BOILER INSTALLATION EQUIPMENT

1.1 . Boiler TGM-96B of the Taganrog Boiler Plant - gas-oil with natural circulation and U-shaped layout, designed to work with turbines T -100/120-130-3 and PT-60-130/13. The main design parameters of the boiler when operating on fuel oil are given in Table. .

According to TKZ, the minimum permissible load the boiler according to the circulation condition is 40% of the nominal.

1.2 . The combustion chamber has a prismatic shape and in plan is a rectangle with dimensions of 6080 × 14700 mm. The volume of the combustion chamber is 1635 m 3 . The thermal stress of the furnace volume is 214 kW/m 3 , or 184 10 3 kcal/(m 3 h). Evaporative screens and a radiation wall superheater (RNS) are placed in the combustion chamber. In the upper part of the furnace in the rotary chamber there is a screen superheater (SHPP). In the lowering convective shaft, two packages of a convective superheater (CSH) and a water economizer (WE) are located in series along the gas flow.

1.3 . The steam path of the boiler consists of two independent flows with steam transfer between the sides of the boiler. The temperature of the superheated steam is controlled by injection of its own condensate.

1.4 . On the front wall of the combustion chamber there are four double-flow oil-gas burners HF TsKB-VTI. The burners are installed in two tiers at elevations of -7250 and 11300 mm with an elevation angle of 10° to the horizon.

For burning fuel oil, steam-mechanical nozzles "Titan" are provided with a nominal capacity of 8.4 t / h at a fuel oil pressure of 3.5 MPa (35 kgf / cm 2). The steam pressure for blowing off and spraying fuel oil is recommended by the plant to be 0.6 MPa (6 kgf/cm2). Steam consumption per nozzle is 240 kg/h.

1.5 . The boiler plant is equipped with:

Two draft fans VDN-16-P with a capacity of 259 10 3 m 3 / h with a margin of 10%, a pressure of 39.8 MPa (398.0 kgf / m 2) with a margin of 20%, a power of 500/250 kW and a rotation speed of 741 /594 rpm each machine;

Two smoke exhausters DN-24 × 2-0.62 GM with a capacity of 10% margin 415 10 3 m 3 / h, pressure with a margin of 20% 21.6 MPa (216.0 kgf / m 2), power 800/400 kW and a speed of 743/595 rpm of each machine.

1.6. To clean the convective heating surfaces from ash deposits, the project provides for a shot plant, for cleaning the RAH - water washing and blowing with steam from a drum with a decrease in pressure in the throttling plant. The duration of blowing one RAH 50 min.

. TYPICAL ENERGY CHARACTERISTICS OF THE TGM-96B BOILER

2.1 . Typical energy characteristic of the TGM-96B boiler ( rice. , , ) was compiled on the basis of the results of thermal tests of boilers at Riga CHPP-2 and CHPP GAZ in accordance with the instructional materials and guidelines on the regulation of technical and economic indicators of boilers. The characteristic reflects the average efficiency of a new boiler operating with turbines T -100/120-130/3 and PT-60-130/13 under the following conditions taken as initial.

2.1.1 . The fuel balance of power plants burning liquid fuels is dominated by high-sulphur fuel oil M 100. Therefore, the characteristic is drawn up for fuel oil M 100 ( GOST 10585-75) with characteristics: A P = 0.14%, W P = 1.5%, S P = 3.5%, (9500 kcal/kg). All necessary calculations are made for the working mass of fuel oil

2.1.2 . The temperature of the fuel oil in front of the nozzles is assumed to be 120 ° C( t t= 120 °С) based on fuel oil viscosity conditions M 100, equal to 2.5 ° VU, according to § 5.41 PTE.

2.1.3 . The average annual temperature of cold air (t x .c.) at the inlet to the blower fan is taken equal to 10 ° C , since TGM-96B boilers are mainly located in climatic regions (Moscow, Riga, Gorky, Chisinau) with an average annual air temperature close to this temperature.

2.1.4 . The air temperature at the inlet to the air heater (t vp) is taken equal to 70 ° C and constant when the boiler load changes, in accordance with § 17.25 PTE.

2.1.5 . For power plants with cross connections, the feed water temperature (t a.c.) in front of the boiler is taken as calculated (230 °C) and constant when the boiler load changes.

2.1.6 . The specific net heat consumption for the turbine plant is assumed to be 1750 kcal/(kWh), according to thermal tests.

2.1.7 . The heat flow coefficient is assumed to vary with the boiler load from 98.5% at rated load to 97.5% at a load of 0.6D number.

2.2 . The calculation of the standard characteristic was carried out in accordance with the instructions of the “Thermal calculation of boiler units (normative method)”, (M.: Energia, 1973).

2.2.1 . The gross efficiency of the boiler and the heat loss with flue gases were calculated in accordance with the methodology described in the book by Ya.L. Pekker "Heat engineering calculations based on the reduced characteristics of the fuel" (M.: Energia, 1977).

where

here

α uh = α "ve + Δ α tr

α uh- coefficient of excess air in the exhaust gases;

Δ α tr- suction cups in the gas path of the boiler;

T uh- flue gas temperature behind the smoke exhauster.

The calculation takes into account the flue gas temperatures measured in the boiler thermal tests and reduced to the conditions for constructing a standard characteristic (input parameterst x in, t "kf, t a.c.).

2.2.2 . Excess air coefficient at the mode point (behind the water economizer)α "ve taken equal to 1.04 at rated load and changing to 1.1 at 50% load according to thermal tests.

The reduction of the calculated (1.13) excess air coefficient downstream of the water economizer to the one adopted in the standard characteristic (1.04) is achieved by the correct maintenance of the combustion mode according to the boiler’s regime map, compliance with the PTE requirements regarding air suction into the furnace and into the gas path and selection of a set of nozzles .

2.2.3 . Air suction into the gas path of the boiler at rated load is taken equal to 25%. With a change in load, air suction is determined by the formula

2.2.4 . Heat losses from chemical incompleteness of fuel combustion (q 3 ) are taken equal to zero, since during the tests of the boiler with excess air, accepted in the Typical energy characteristic, they were absent.

2.2.5 . Heat loss from mechanical incompleteness of fuel combustion (q 4 ) are taken equal to zero according to the "Regulations on the harmonization of the regulatory characteristics of equipment and estimated specific fuel consumption" (M.: STsNTI ORGRES, 1975).

2.2.6 . Heat loss in environment (q 5 ) were not determined during the tests. They are calculated in accordance with the "Method of testing boiler plants" (M.: Energia, 1970) according to the formula

2.2.7 . The specific power consumption for the feed electric pump PE-580-185-2 was calculated using the characteristics of the pump adopted from the specifications TU-26-06-899-74.

2.2.8 . The specific power consumption for draft and blast is calculated from the power consumption for the drive of draft fans and smoke exhausters, measured during thermal tests and reduced to the conditions (Δ α tr= 25%), adopted in the preparation of the regulatory characteristics.

It has been established that at a sufficient density of the gas path (Δ α ≤ 30%) smoke exhausters provide the rated load of the boiler at low speed, but without any reserve.

Blow fans at low speed ensure normal operation of the boiler up to loads of 450 t/h.

2.2.9 . The total electric power of the mechanisms of the boiler plant includes the power of electric drives: electric feed pump, smoke exhausters, fans, regenerative air heaters (Fig. ). The power of the electric motor of the regenerative air heater is taken according to the passport data. The power of the electric motors of smoke exhausters, fans and the electric feed pump was determined during the thermal tests of the boiler.

2.2.10 . The specific heat consumption for air heating in a calorific unit is calculated taking into account air heating in fans.

2.2.11 . AT specific consumption heat for own needs of the boiler plant includes heat losses in heaters, the efficiency of which is assumed to be 98%; for steam blowing of RAH and heat loss with steam blowing of the boiler.

The heat consumption for steam blowing of RAH was calculated by the formula

Q obd = G obd · i obd · τ obd 10 -3 MW (Gcal/h)

where G obd= 75 kg/min in accordance with the "Standards for the consumption of steam and condensate for auxiliary needs of power units 300, 200, 150 MW" (M.: STSNTI ORGRES, 1974);

i obd = i us. pair= 2598 kJ/kg (kcal/kg)

τ obd= 200 min (4 devices with a blowing time of 50 min when switched on during the day).

The heat consumption with the boiler blowdown was calculated by the formula

Q prod = G prod · i k.v10 -3 MW (Gcal/h)

where G prod = PD nom 10 2 kg/h

P = 0.5%

i k.v- enthalpy of boiler water;

2.2.12 . The procedure for conducting tests and the choice of measuring instruments used in the tests were determined by the "Method of testing boiler plants" (M .: Energia, 1970).

. AMENDMENTS TO REGULATIONS

3.1 . In order to bring the main normative indicators of the boiler operation to the changed conditions of its operation within the permissible deviation limits of the parameter values, amendments are given in the form of graphs and numerical values. Amendments toq 2 in the form of graphs are shown in fig. , . Corrections to flue gas temperature are shown in fig. . In addition to the above, corrections are given for the change in the temperature of heating fuel oil supplied to the boiler, and for the change in the temperature of the feed water.


Description of the object.

Full name:“Automated training course “Operation of the TGM-96B boiler unit when burning fuel oil and natural gas”.

Symbol:

Year of issue: 2007.

The automated training course for the operation of the TGM-96B boiler unit was developed to train operational personnel servicing boiler plants of this type and is a means of training, pre-examination training and examination testing of CHP personnel.

AUK is compiled on the basis of regulatory and technical documentation used in the operation of TGM-96B boilers. It contains textual and graphical material for interactive study and testing of students.

This AUC describes the design and technological characteristics the main and auxiliary equipment of TGM-96B boilers, namely: a combustion chamber, a drum, a superheater, a convection shaft, a power unit, draft devices, steam and water temperature control, etc.

Starting, normal, emergency and shutdown modes of operation of the boiler plant are considered, as well as the main reliability criteria for heating and cooling down steam pipelines, screens and other elements of the boiler.

The system of automatic control of the boiler, the system of protections, interlocks and alarms are considered.

The procedure for admission to inspection, testing, repair of equipment, safety rules and explosion and fire safety have been determined.

The composition of the AUC:

Automated training course (ATC) is a software tool designed for initial training and subsequent testing of knowledge of power plant personnel and electrical networks. First of all, for the training of operational and operational-repair personnel.

The basis of the AUC is the operating production and job descriptions, regulatory materials, data from equipment manufacturers.

AUC includes:

  • section of general theoretical information;
  • a section that deals with the design and operation of a particular type of equipment;
  • student self-examination section;
  • examiner block.

In addition to texts, AUC contains the necessary graphic material (diagrams, drawings, photographs).

Information content of AUK.

The text material is based on the operating instructions for the TGM-96 boiler unit, factory instructions, other regulatory and technical materials and includes the following sections:

1. Short description design of the TGM-96 boiler unit.
1.1. Main settings.
1.2. Boiler layout.
1.3. Furnace chamber.
1.3.1. General information.
1.3.2. Placement of heating surfaces in the furnace.
1.4. Burner device.
1.4.1. General information.
1.4.2. Specifications burners.
1.4.3. Oil nozzles.
1.5. Drum and separation device.
1.5.1. General information.
1.5.2. Intradrum device.
1.6. Superheater.
1.6.1. General information.
1.6.2. Radiation superheater.
1.6.3. Ceiling superheater.
1.6.4. Shielded steam heater.
1.6.5. Convective superheater.
1.6.6. Scheme of steam movement.
1.7. A device for controlling the temperature of superheated steam.
1.7.1. condensation plant.
1.7.2. injection devices.
1.7.3. Scheme of supply of condensate and feed water.
1.8. Water economizer.
1.8.1. General information.
1.8.2. Suspended part of the economizer.
1.8.3. Wall economizer panels.
1.8.4. convective economizer.
1.9. Air heater.
1.10. Boiler frame.
1.11. Boiler lining.
1.12. Cleaning of heating surfaces.
1.13. Thrust installation.
2. Extract from the thermal calculation.
2.1. The main characteristics of the boiler.
2.2. Excess air coefficients.
2.3. Thermal balance and characteristics of the furnace.
2.4. The temperature of the combustion products.
2.5. steam temperatures.
2.6. Water temperatures.
2.7. Air temperatures.
2.8. Condensate consumption for injection.
2.9. boiler resistance.
3. Preparing the boiler for cold start.
3.1. Inspection and testing of equipment.
3.2. Preparation of lighting schemes.
3.2.1. Assembling circuits for warming up a reduced power unit and injections.
3.2.2. Assembly of schemes for steam pipelines and a superheater.
3.2.3. Assembly of the gas-air path.
3.2.4. Preparation of gas pipelines of the boiler.
3.2.5. Assembly of fuel oil pipelines within the boiler.
3.3. Filling the boiler with water.
3.3.1. General provisions.
3.3.2. Operations before filling.
3.3.3. Operations after filling.
4. Kindling the boiler.
4.1. A common part.
4.2. Kindling on gas from a cold state.
4.2.1. Furnace ventilation.
4.2.2. Filling the pipeline with gas.
4.2.3. Checking the gas pipeline and fittings within the boiler for tightness.
4.2.4. Ignition of the first burner.
4.2.5. Ignition of the second and subsequent burners.
4.2.6. Purging of water-indicating columns.
4.2.7. Boiler firing schedule.
4.2.8. Purging the bottom points of the screens.
4.2.9. Temperature regime radiation superheater during kindling.
4.2.10. Temperature regime of the water economizer during kindling.
4.2.11. Inclusion of the boiler in the main.
4.2.12. Raising the load to nominal.
4.3. Boiler kindling from a hot state.
4.4. Fire-up of the boiler using the boiler water recirculation scheme.
5. Maintenance of the boiler and equipment during operation.
5.1. General provisions.
5.1.1. The main tasks of the operating personnel.
5.1.2. Boiler steam output regulation.
5.2. Boiler service.
5.2.1. Observations during the operation of the boiler.
5.2.2. Boiler power.
5.2.3. Superheated steam temperature control.
5.2.4. Combustion control.
5.2.5. Boiler purge.
5.2.6. Oil boiler operation.
6. Switching from one type of fuel to another.
6.1. Switching from natural gas to fuel oil.
6.1.1. Transfer of the burner from gas combustion to fuel oil from the main control room.
6.1.2. Transfer of the burner from fuel oil to natural gas on site.
6.2. Switching from fuel oil to natural gas.
6.2.1. Transfer of the heater from fuel oil combustion to natural gas from the main control room.
6.2.2. Transfer of the burner from fuel oil to natural gas on site.
6.3. Co-firing of natural gas and fuel oil.
7. Stop the boiler.
7.1. General provisions.
7.2. Stop the boiler in reserve.
7.2.1. Actions of personnel during shutdown.
7.2.2. Testing of safety valves.
7.2.3. Actions of personnel after shutdown.
7.3. Boiler shutdown with cooldown.
7.4. Boiler emergency stop.
7.4.1. Cases of emergency shutdown of the boiler by protection or personnel.
7.4.2. Cases of emergency shutdown of the boiler by order of the chief engineer.
7.4.3. Remote shutdown of the boiler.
8. Emergencies and the procedure for their elimination.
8.1. General provisions.
8.1.1. A common part.
8.1.2. Responsibilities of the personnel on duty in case of an accident.
8.1.3. Personnel actions during an accident.
8.2. Load shedding.
8.3. Station load shedding with loss of auxiliary needs.
8.4. Lowering of the water level.
8.4.1. Signs of downgrading and actions of personnel.
8.4.2. Actions of the personnel after the liquidation of the accident.
8.5. Rising water level.
8.5.1. Signs and actions of personnel.
8.5.2. Actions of personnel in case of failure of the protection.
8.6. Failure of all water-indicating devices.
8.7. Screen pipe rupture.
8.8. Rupture of the superheater pipe.
8.9. Rupture of the water economizer pipe.
8.10. Detection of cracks in pipelines and steam fittings of the boiler.
8.11. Increasing pressure in the drum over 170 atm and failure of safety valves.
8.12. Stopping the gas supply.
8.13. Reducing the oil pressure behind the control valve.
8.14. Shutdown of both smoke exhausters.
8.15. Turn off both blowers.
8.16. Disable all RVPs.
8.17. Ignition of deposits in air heaters.
8.18. Explosion in the furnace or gas ducts of the boiler.
8.19. Breakage of the torch, unstable combustion mode, pulsation in the furnace.
8.20. Throwing water into the superheater.
8.21. Rupture of the main fuel oil pipeline.
8.22. Rupture or fire on fuel oil pipelines within the boiler.
8.23. Gap or fire on the main gas pipelines.
8.24. Gap or fire on gas pipelines within the boiler.
8.25. Decreasing the outdoor air temperature below the calculated one.
9. Boiler automation.
9.1. General provisions.
9.2. Level regulator.
9.3. combustion regulator.
9.4. Superheated steam temperature controller.
9.5. Continuous purge regulator.
9.6. Water Phosphating Regulator.
10. Thermal protection of the boiler.
10.1. General provisions.
10.2. Boiler overfeeding protection.
10.3. Level-down protection.
10.4. Protection when turning off smoke exhausters or blowers.
10.5. Protection when all RVPs are turned off.
10.6. Emergency stop of the boiler with a button.
10.7. Fuel pressure drop protection.
10.8. Gas pressure increase protection.
10.9. Operation of the fuel switch.
10.10. Flame extinguishing protection in the furnace.
10.11. Protection for increasing the temperature of superheated steam behind the boiler.
11. Technological protection and alarm settings.
11.1. Process alarm settings.
11.2. Technological protection settings.
12. Impulse-safety devices of the boiler.
12.1. General provisions.
12.2. IPU operation.
13. Safety and fire prevention measures.
13.1. A common part.
13.2. Safety regulations.
13.3. Safety measures when taking the boiler out for repair.
13.4. Safety and fire safety requirements.
13.4.1. General information.
13.4.2. Safety requirements.
13.4.3. Safety requirements for the operation of the boiler on fuel oil substitutes.
13.4.4. fire safety requirements.

14. Graphic material in this AUK is presented as part of 17 figures and diagrams:
14.1. The layout of the boiler TGM-96B.
14.2. Under the combustion chamber.
14.3. Screen pipe attachment point.
14.4. The layout of the burners.
14.5. Burner device.
14.6. Intradrum device.
14.7. condensation plant.
14.8. Scheme of a reduced power unit and boiler injections.
14.9. Desuperheater.
14.10. Assembling a circuit for warming up a reduced power unit.
14.11. Scheme of kindling the boiler (steam path).
14.12. Scheme of gas-air ducts of the boiler.
14.13. Scheme of gas pipelines within the boiler.
14.14. Scheme of fuel oil pipelines within the boiler.
14.15. Furnace ventilation.
14.16. Filling the pipeline with gas.
14.17. Checking the gas pipeline for tightness.

Knowledge check

After studying the textual and graphic material, the student can launch a program of self-testing knowledge. The program is a test that checks the degree of assimilation of the material of the instruction. In case of an erroneous answer, the operator is shown an error message and a quote from the text of the instruction containing the correct answer. The total number of questions in this course is 396.

Exam

After completing the training course and self-control of knowledge, the student takes an examination test. It includes 10 questions automatically selected at random from among the questions provided for self-test. During the exam, the examinee is asked to answer these questions without prompts and the opportunity to refer to the textbook. No error messages are displayed until the end of testing. After the end of the exam, the student receives a protocol that contains the proposed questions, the answers chosen by the examiner and comments on erroneous answers. The exam grade is set automatically. The test protocol is stored on the hard drive of the computer. It is possible to print it on a printer.

MINISTRY OF ENERGY AND ELECTRIFICATION OF THE USSR

MAIN TECHNICAL DEPARTMENT FOR OPERATION
ENERGY SYSTEMS

TYPICAL ENERGY DATA
OF THE TGM-96B BOILER FOR FUEL FUEL COMBUSTION

Moscow 1981

This Typical Energy Characteristic was developed by Soyuztekhenergo (engineer G.I. GUTSALO)

The typical energy characteristic of the TGM-96B boiler was compiled on the basis of thermal tests conducted by Soyuztekhenergo at the Riga CHPP-2 and Sredaztekhenergo at the CHPP-GAZ, and reflects the technically achievable efficiency of the boiler.

A typical energy characteristic can serve as the basis for compiling the standard characteristics of TGM-96B boilers when burning fuel oil.



Appendix

. BRIEF DESCRIPTION OF THE BOILER INSTALLATION EQUIPMENT

1.1 . Boiler TGM-96B of the Taganrog Boiler Plant - gas-oil with natural circulation and U-shaped layout, designed to work with turbines T -100/120-130-3 and PT-60-130/13. The main design parameters of the boiler when operating on fuel oil are given in Table. .

According to the TKZ, the minimum allowable load of the boiler according to the circulation condition is 40% of the nominal one.

1.2 . The combustion chamber has a prismatic shape and in plan is a rectangle with dimensions of 6080 × 14700 mm. The volume of the combustion chamber is 1635 m 3 . The thermal stress of the furnace volume is 214 kW/m 3 , or 184 10 3 kcal/(m 3 h). Evaporative screens and a radiation wall superheater (RNS) are placed in the combustion chamber. In the upper part of the furnace in the rotary chamber there is a screen superheater (SHPP). In the lowering convective shaft, two packages of a convective superheater (CSH) and a water economizer (WE) are located in series along the gas flow.

1.3 . The steam path of the boiler consists of two independent flows with steam transfer between the sides of the boiler. The temperature of the superheated steam is controlled by injection of its own condensate.

1.4 . On the front wall of the combustion chamber there are four double-flow oil-gas burners HF TsKB-VTI. The burners are installed in two tiers at elevations of -7250 and 11300 mm with an elevation angle of 10° to the horizon.

For burning fuel oil, steam-mechanical nozzles "Titan" are provided with a nominal capacity of 8.4 t / h at a fuel oil pressure of 3.5 MPa (35 kgf / cm 2). The steam pressure for blowing off and spraying fuel oil is recommended by the plant to be 0.6 MPa (6 kgf/cm2). Steam consumption per nozzle is 240 kg/h.

1.5 . The boiler plant is equipped with:

Two draft fans VDN-16-P with a capacity of 259 10 3 m 3 / h with a margin of 10%, a pressure of 39.8 MPa (398.0 kgf / m 2) with a margin of 20%, a power of 500/250 kW and a rotation speed of 741 /594 rpm each machine;

Two smoke exhausters DN-24 × 2-0.62 GM with a capacity of 10% margin 415 10 3 m 3 / h, pressure with a margin of 20% 21.6 MPa (216.0 kgf / m 2), power 800/400 kW and a speed of 743/595 rpm of each machine.

1.6. To clean the convective heating surfaces from ash deposits, the project provides for a shot plant, for cleaning the RAH - water washing and blowing with steam from a drum with a decrease in pressure in the throttling plant. The duration of blowing one RAH 50 min.

. TYPICAL ENERGY CHARACTERISTICS OF THE TGM-96B BOILER

2.1 . Typical energy characteristic of the TGM-96B boiler ( rice. , , ) was compiled on the basis of the results of thermal tests of boilers at Riga CHPP-2 and CHPP GAZ in accordance with the instructive materials and methodological guidelines for standardizing the technical and economic indicators of boilers. The characteristic reflects the average efficiency of a new boiler operating with turbines T -100/120-130/3 and PT-60-130/13 under the following conditions taken as initial.

2.1.1 . The fuel balance of power plants burning liquid fuels is dominated by high-sulphur fuel oil M 100. Therefore, the characteristic is drawn up for fuel oil M 100 (GOST 10585-75 ) with characteristics: A P = 0.14%, W P = 1.5%, S P = 3.5%, (9500 kcal/kg). All necessary calculations are made for the working mass of fuel oil

2.1.2 . The temperature of the fuel oil in front of the nozzles is assumed to be 120 ° C( t t= 120 °С) based on fuel oil viscosity conditions M 100, equal to 2.5 ° VU, according to § 5.41 PTE.

2.1.3 . The average annual temperature of cold air (t x .c.) at the inlet to the blower fan is taken equal to 10 ° C , since TGM-96B boilers are mainly located in climatic regions (Moscow, Riga, Gorky, Chisinau) with an average annual air temperature close to this temperature.

2.1.4 . The air temperature at the inlet to the air heater (t vp) is taken equal to 70 ° C and constant when the boiler load changes, in accordance with § 17.25 PTE.

2.1.5 . For power plants with cross connections, the feed water temperature (t a.c.) in front of the boiler is taken as calculated (230 °C) and constant when the boiler load changes.

2.1.6 . The specific net heat consumption for the turbine plant is assumed to be 1750 kcal/(kWh), according to thermal tests.

2.1.7 . The heat flow coefficient is assumed to vary with the boiler load from 98.5% at rated load to 97.5% at a load of 0.6D number.

2.2 . The calculation of the standard characteristic was carried out in accordance with the instructions of the “Thermal calculation of boiler units (normative method)”, (M.: Energia, 1973).

2.2.1 . The gross efficiency of the boiler and the heat loss with flue gases were calculated in accordance with the methodology described in the book by Ya.L. Pekker "Heat engineering calculations based on the reduced characteristics of the fuel" (M.: Energia, 1977).

where

here

α uh = α "ve + Δ α tr

α uh- coefficient of excess air in the exhaust gases;

Δ α tr- suction cups in the gas path of the boiler;

T uh- flue gas temperature behind the smoke exhauster.

The calculation takes into account the flue gas temperatures measured in the boiler thermal tests and reduced to the conditions for constructing a standard characteristic (input parameterst x in, t "kf, t a.c.).

2.2.2 . Excess air coefficient at the mode point (behind the water economizer)α "ve taken equal to 1.04 at rated load and changing to 1.1 at 50% load according to thermal tests.

The reduction of the calculated (1.13) excess air coefficient downstream of the water economizer to the one adopted in the standard characteristic (1.04) is achieved by the correct maintenance of the combustion mode according to the boiler’s regime map, compliance with the PTE requirements regarding air suction into the furnace and into the gas path and selection of a set of nozzles .

2.2.3 . Air suction into the gas path of the boiler at rated load is taken equal to 25%. With a change in load, air suction is determined by the formula

2.2.4 . Heat losses from chemical incompleteness of fuel combustion (q 3 ) are taken equal to zero, since during the tests of the boiler with excess air, accepted in the Typical energy characteristic, they were absent.

2.2.5 . Heat loss from mechanical incompleteness of fuel combustion (q 4 ) are taken equal to zero according to the "Regulations on the harmonization of the regulatory characteristics of equipment and estimated specific fuel consumption" (M.: STsNTI ORGRES, 1975).

2.2.6 . Heat loss to the environment (q 5 ) were not determined during the tests. They are calculated in accordance with the "Method of testing boiler plants" (M.: Energia, 1970) according to the formula

2.2.7 . The specific power consumption for the feed electric pump PE-580-185-2 was calculated using the characteristics of the pump adopted from the specifications TU-26-06-899-74.

2.2.8 . The specific power consumption for draft and blast is calculated from the power consumption for the drive of draft fans and smoke exhausters, measured during thermal tests and reduced to the conditions (Δ α tr= 25%), adopted in the preparation of the regulatory characteristics.

It has been established that at a sufficient density of the gas path (Δ α ≤ 30%) smoke exhausters provide the rated load of the boiler at low speed, but without any reserve.

Blow fans at low speed ensure normal operation of the boiler up to loads of 450 t/h.

2.2.9 . The total electric power of the mechanisms of the boiler plant includes the power of electric drives: electric feed pump, smoke exhausters, fans, regenerative air heaters (Fig. ). The power of the electric motor of the regenerative air heater is taken according to the passport data. The power of the electric motors of smoke exhausters, fans and the electric feed pump was determined during the thermal tests of the boiler.

2.2.10 . The specific heat consumption for air heating in a calorific unit is calculated taking into account air heating in fans.

2.2.11 . The specific heat consumption for auxiliary needs of the boiler plant includes heat losses in heaters, the efficiency of which is assumed to be 98%; for steam blowing of RAH and heat loss with steam blowing of the boiler.

The heat consumption for steam blowing of RAH was calculated by the formula

Q obd = G obd · i obd · τ obd 10 -3 MW (Gcal/h)

where G obd= 75 kg/min in accordance with the "Standards for the consumption of steam and condensate for auxiliary needs of power units 300, 200, 150 MW" (M.: STSNTI ORGRES, 1974);

i obd = i us. pair= 2598 kJ/kg (kcal/kg)

τ obd= 200 min (4 devices with a blowing time of 50 min when switched on during the day).

The heat consumption with the boiler blowdown was calculated by the formula

Q prod = G prod · i k.v10 -3 MW (Gcal/h)

where G prod = PD nom 10 2 kg/h

P = 0.5%

i k.v- enthalpy of boiler water;

2.2.12 . The procedure for conducting tests and the choice of measuring instruments used in the tests were determined by the "Method of testing boiler plants" (M .: Energia, 1970).

. AMENDMENTS TO REGULATIONS

3.1 . In order to bring the main normative indicators of the boiler operation to the changed conditions of its operation within the permissible deviation limits of the parameter values, amendments are given in the form of graphs and numerical values. Amendments toq 2 in the form of graphs are shown in fig. , . Corrections to flue gas temperature are shown in fig. . In addition to the above, corrections are given for the change in the temperature of heating fuel oil supplied to the boiler, and for the change in the temperature of the feed water.

3.1.1 . The correction for the change in the temperature of the fuel oil supplied to the boiler is calculated from the effect of the change To Q on the q 2 by formula