MINISTRY OF ENERGY AND ELECTRIFICATION OF THE USSR
MAIN TECHNICAL DEPARTMENT FOR OPERATION
ENERGY SYSTEMS
TYPICAL ENERGY CHARACTERISTICS
BOILER TGM-96B FOR FUEL OIL COMBUSTION
Moscow 1981
This Standard Energy Characteristic was developed by Soyuztekhenergo (eng. G.I. GUTSALO)
The typical energy characteristics of the TGM-96B boiler are compiled on the basis of thermal tests carried out by Soyuztekhenergo at Riga CHPP-2 and Sredaztekhenergo at CHPP-GAZ, and reflect the technically achievable efficiency of the boiler.
A typical energy characteristic can serve as the basis for drawing up standard characteristics of TGM-96B boilers when burning fuel oil.
Application
. BRIEF CHARACTERISTICS OF BOILER EQUIPMENT
1.1 . TGM-96B boiler of the Taganrog Boiler Plant - gas-oil boiler 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 boiler load according to circulation conditions is 40% of the nominal one.
1.2 . The combustion chamber has a prismatic shape and in plan is a rectangle with dimensions 6080x14700 mm. The volume of the combustion chamber is 1635 m3. The thermal voltage of the combustion volume is 214 kW/m 3, or 184 · 10 3 kcal/(m 3 · h). The combustion chamber contains evaporation screens and a radiation wall-mounted steam superheater (WSR) on the front wall. In the upper part of the furnace, a screen steam superheater (SSH) is located in the rotating chamber. In the lower convective shaft, two packages of a convective steam superheater (CS) and a water economizer (WES) are located sequentially along the flow of gases.
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 regulated by the injection of its own condensate.
1.4 . On the front wall of the combustion chamber there are four double-flow gas-oil burners HF TsKB-VTI. The burners are installed in two tiers at levels of -7250 and 11300 mm with an elevation angle to the horizon of 10°.
To burn fuel oil, Titan steam-mechanical nozzles are provided with a nominal capacity of 8.4 t/h at a fuel oil pressure of 3.5 MPa (35 kgf/cm2). The steam pressure for purging and spraying fuel oil is recommended by the plant to be 0.6 MPa (6 kgf/cm2). The steam consumption per nozzle is 240 kg/h.
1.5 . The boiler installation is equipped with:
Two VDN-16-P blower fans with a capacity of 259 · 10 3 m 3 /h with a reserve of 10%, a pressure with a reserve of 20% of 39.8 MPa (398.0 kgf/m 2), a power of 500/250 kW and a rotation speed of 741 /594 rpm of each machine;
Two smoke exhausters DN-24×2-0.62 GM with a capacity of 415 10 3 m 3 /h with a margin of 10%, a pressure with a margin of 20% of 21.6 MPa (216.0 kgf/m2), power of 800/400 kW and a rotation speed of 743/595 rpm for each machine.
1.6. To clean convective heating surfaces from ash deposits, the project provides for a shot installation; for cleaning the RVP, water washing and blowing with steam from a drum with a decrease in pressure in the throttling installation. The duration of blowing one RVP is 50 minutes.
. TYPICAL ENERGY CHARACTERISTICS OF THE TGM-96B BOILER
2.1 . Typical energy characteristics of the TGM-96B boiler ( rice. , , ) was compiled on the basis of the results of thermal tests of boilers at Riga CHPP-2 and GAZ CHPP in accordance with instructional materials and 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 conditions below, taken as initial ones.
2.1.1
. In the fuel balance of power plants burning liquid fuels, the majority is high-sulfur fuel oil M 100. Therefore, the characteristics are 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 were made for the working mass of fuel oil
2.1.2 . The fuel oil temperature in front of the nozzles is assumed to be 120 ° C ( t tl= 120 °C) based on fuel oil viscosity conditions M 100, equal to 2.5° VU, according to § 5.41 PTE.
2.1.3 . Average annual cold air temperature (t x .v.) at the entrance to the blower fan is taken to be 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 . Air temperature at the inlet to the air heater (t ch) is taken to be 70° C and constant when the boiler load changes, according to § 17.25 of the PTE.
2.1.5 . For cross-coupled power plants, the feedwater temperature (t p.v.) in front of the boiler is assumed to be calculated (230 °C) and constant when the boiler load changes.
2.1.6 . The specific net heat consumption for the turbine unit 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 0.6 loadD nom.
2.2 . The calculation of the standard characteristics was carried out in accordance with the instructions of “Thermal calculation of boiler units (normative method)” (M.: Energia, 1973).
2.2.1 . The gross efficiency of the boiler and heat loss with flue gases were calculated in accordance with the methodology outlined in the book by Ya.L. Pekker “Thermal engineering calculations based on the given fuel characteristics” (Moscow: Energia, 1977).
Where
Here
α х = α "ve + Δ α tr
α х- coefficient of excess air in exhaust gases;
Δ α tr- suction cups into the gas path of the boiler;
Ugh- temperature of the flue gases behind the smoke exhauster.
The calculation includes the flue gas temperature values measured in boiler thermal tests and reduced to the conditions for constructing the standard characteristics (input parameterst x in, t "kf, t p.v.).
2.2.2 . Excess air coefficient at the operating point (behind the water economizer)α "ve assumed to be 1.04 at rated load and varying to 1.1 at 50% load based on thermal testing.
Reducing the calculated (1.13) coefficient of excess air behind the water economizer to that accepted in the standard specification (1.04) is achieved by correctly maintaining the combustion mode in accordance with the boiler regime map, complying with the requirements of the PTE in relation to air intake into the furnace and into the gas path and selecting a set of nozzles .
2.2.3 . Air suction into the gas path of the boiler at rated load is assumed to be 25%. With a change in load, air suction is determined by the formula
2.2.4 . Heat loss from chemical incomplete combustion of fuel (q 3 ) are taken equal to zero, since during tests of the boiler with excess air, accepted in the Standard Energy Characteristics, they were absent.
2.2.5 . Heat loss from mechanical incomplete combustion of fuel (q 4 ) are taken equal to zero according to the “Regulations on the coordination of standard characteristics of equipment and calculated specific fuel consumption” (Moscow: STSNTI ORGRES, 1975).
2.2.6 . Heat loss to the environment (q 5 ) were not determined during testing. They are calculated in accordance with the “Methods for testing boiler installations” (M.: Energia, 1970) according to the formula
2.2.7 . The specific energy consumption for the electric feed pump PE-580-185-2 was calculated using the pump characteristics adopted from the technical specifications TU-26-06-899-74.
2.2.8 . The specific energy consumption for draft and blast is calculated based on the energy consumption for driving blower fans and smoke exhausters, measured during thermal tests and reduced to conditions (Δ α tr= 25%) adopted when drawing up the normative characteristics.
It has been established that with sufficient density of the gas path (Δ α ≤ 30%) smoke exhausters provide the rated boiler load at low speed, but without any reserve.
Blower fans at low rotation speed ensure normal operation of the boiler up to loads of 450 t/h.
2.2.9 . The total electrical power of the boiler installation mechanisms 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 the smoke exhausters, fans and electric feed pump was determined during thermal tests of the boiler.
2.2.10 . The specific heat consumption for heating the air in the heating unit is calculated taking into account the heating of the air in the fans.
2.2.11 . The specific heat consumption for the boiler plant’s own needs includes heat losses in air heaters, the efficiency of which is assumed to be 98%; for steam blowing of the RVP and heat losses due to steam blowing of the boiler.
The heat consumption for steam blowing of the RVP was calculated using 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 steam and condensate consumption for auxiliary needs of power units of 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 duration of 50 min when turned on during the day).
Heat consumption with boiler blowing was calculated using the formula
Q cont = G prod · i k.v· 10 -3 MW (Gcal/h)
Where G prod = PD no. 10 2 kg/h
P = 0.5%
i k.v- enthalpy of boiler water;
2.2.12 . The procedure for testing and the choice of measuring instruments used during testing were determined by the “Methodology for testing boiler installations” (M.: Energia, 1970).
. AMENDMENTS TO REGULATORY INDICATORS
3.1 . To bring the main standard indicators of boiler operation to the changed conditions of its operation within the permissible limits of deviation of parameter values, amendments are given in the form of graphs and digital values. Amendments toq 2 in the form of graphs are shown in Fig. , . Corrections to the flue gas temperature are shown in Fig. . In addition to those listed, corrections are given for changes in the heating temperature of the fuel oil supplied to the boiler and for changes in the temperature of the feed water.
3.1.1 . The correction for changes in the temperature of the fuel oil supplied to the boiler is calculated based on the effect of changes TO Q on q 2 by formula
Description of the steam boiler TGM-151-B
Laboratory work No. 1
on the course "Boiler installations"
Completed by: Matyushina E.
Pokachalova Yu.
Titova E.
Group: TE-10-1
Checked by: Shatskikh Yu.V.
Lipetsk 2013
1. Purpose of the work……………………………………………………………………………….3
2. Brief characteristics of the TGM-151-B boiler………………………………………………………..….3
3. Boiler and auxiliary equipment……………………………...……………….4
4. Characteristics of equipment……………………………...…………………………7
4.1 Technical characteristics……………………………….………………….7
4.2 Description of design……………………………………..……………….7
4.2.1 Combustion chamber……………………….…..………………………….….7
4.2.2 Superheater……………………...…………………………….8
4.2.3 Device for regulating the temperature of superheated steam………………………………………………………………………………………….…….11
4.2.4 Water economizer…………………...…...………………………......11
4.2.5 Air heater…………………………...………………..…..…12
4.2.6 Draft devices……………………...………………………..…12
4.2.7 Safety valves………………..……………………………13
4.2.8 Burner devices…………………………..………………………..13
4.2.9 Drum and separation devices…………………………………......14
4.2.10 Boiler frame…………....……………………………………………………………16
4.2.11. Boiler lining……….…....………………………………….…….….16
5. Safety precautions during work……………………………………….16
Bibliography………………………..………………………………………………………...17
1. Purpose of the work
Thermal testing of boiler installations is carried out to determine the energy characteristics that determine their operating performance depending on the load and type of fuel, to identify their operational features and design flaws. To instill practical skills in students, it is recommended that this work be carried out in production conditions at existing thermal power plant installations.
The purpose of the work is to familiarize students with the organization and methodology for carrying out balance tests of a boiler unit, determining the number and selection of measurement points for boiler operating parameters, the requirements for installing instrumentation, and the methodology for processing test results.
Brief characteristics of the TGM-151-B boiler
1. Registration number No. 10406
2 Manufacturing plant Taganrog boiler house
Krasny Kotelshchik plant
3. Steam capacity 220 t/h
4. Steam pressure in the drum 115 kg/cm2
5. Nominal pressure of superheated steam 100 kg/cm2
6. Temperature of superheated steam 540 °C
7. Feedwater temperature 215 °C
8. Hot air temperature 340 °C
9. Water temperature at the economizer outlet 320 °C
10. Flue gas temperature 180 °C
11. Main fuel Coke blast furnace gas and natural gas
12 Reserve fuel fuel oil
Boiler and auxiliary equipment.
1. Type of smoke exhauster: D-20x2
Capacity 245 thousand m3/h
Smoke exhaust vacuum - 408 kgf/m2
Power and type of electric motor No. 21 500 kW A13-52-8
No. 22 500 kW A4-450-8
2. Blower type: VDN -18-11
Productivity - 170 thousand m/h
Pressure - 390 kgf/m2
Power and type of electric motor No. 21 200 kW AO-113-6
No. 22 165 kW GAMT 6-127-6
3. Burner type: Turbulent
Number of burners (natural gas) - 4
Number of burners (coke blast furnace gas) 4
Minimum air pressure - 50mm h.st.
Air flow through the burner - 21000 nm/hour
Air temperature in front of the burner - 340 C
Natural gas flow through the burner - 2200 nm/hour
Consumption of coke blast furnace gas through the burner - 25000 nm/hour
Figure 1. Gas-oil boiler TGM-151-B for 220 t/h, 100 kgf/cm^2 (longitudinal and cross sections): 1 – drum, 2 – remote separation cyclone, 3 – combustion chamber, 4 – fuel burner, 5 – screen, 6 – convective part of the superheater, 7 – economizer, 8 – regenerative air heater, 9 – shot catcher (cyclone) of the shot blasting unit, 10 – hopper of the shot blasting unit, 11 – box that removes flue gases from the economizer to the air heater, 12 – gas box to smoke exhauster, 13 – cold air box.
Figure 2. General diagram of the TGM-151-B boiler: 1 – drum, 2 – external separation cyclone, 3 – burner, 4 – screen pipes, 5 – lower pipes, 6 – ceiling superheater, 7 – radiation screen superheater, 8 – convective screen superheater, 9 – 1st stage of convective superheater, 10 – 2nd stage of convective superheater, 11 – 1st injection desuperheater,
12 – 2nd injection desuperheater, 13 – water economizer packages, 14 – regenerative rotating air heater.
4. Equipment characteristics
4.1 Technical characteristics
The TGM-151/B boiler is gas-oil, vertical-water-tube, single-drum, with natural circulation and three-stage evaporation. The boiler was manufactured by the Taganrog boiler plant "Krasny Kotelshchik".
The boiler unit has a U-shaped layout and consists of a combustion chamber, a rotary chamber and a lower convective shaft.
In the upper part of the furnace (at the exit from it), the screen part of the superheater is located in the rotating chamber, and the convective part of the superheater and the economizer are located in the lower gas duct. Two regenerative rotating air heaters (RAH) are installed behind the convective flue.
Operational indicators, parameters:
4.2 Design description
4.2.1 Combustion chamber
The combustion chamber has a prismatic shape. The volume of the combustion chamber is 780 m3.
The walls of the combustion chamber are shielded with pipes Ø 60x5, made of steel 20. The ceiling of the combustion chamber is shielded with pipes of a ceiling superheater (Ø 32x3.5).
The front screen consists of 4 panels - 38 pipes in the outer panels and 32 pipes in the middle ones. The side screens have three panels - each with 30 pipes. The rear screen has 4 panels: the two outer panels consist of 38 pipes, the middle ones - of 32 pipes.
To improve the flushing of screens with flue gases and protect the rear screen cameras from radiation, the rear screen pipes in the upper part form a protrusion into the firebox with an overhang of 2000 mm (along the axes of the pipes). Thirty-four pipes do not participate in the formation of the overhang, but are load-bearing (9 pipes in the outer panels and 8 in the middle ones).
The screen system, except for the rear screen, is suspended from the upper chambers by means of ties to the metal structures of the ceiling. The rear screen panels are suspended using 12 heated hanging pipes 0 133x10 to the ceiling.
The panels of the rear screens in the lower part form a slope towards the front wall of the firebox with a slope of 15° to the horizontal and form a cold floor, covered on the side of the firebox with fireclay and chrome-plated mass.
All firebox screens expand freely downward.
Figure 3. Sketch of the combustion chamber of a gas-oil boiler.
Figure 4. Screen heating surfaces of the boiler: 1 – drum; 2 – upper collector; 3 – lowering pipe bundle; 4 – lifting evaporation beam; 9 – lower manifold of the rear screen; 13 – mixture drainage pipes of the rear screen; 14 – heating of the screen with a torch of burning fuel.
4.2.2 Superheater
The boiler superheater consists of the following parts (along the steam path): a ceiling superheater, a screen superheater and a convective superheater. The ceiling superheater shields the ceiling of the firebox and rotary chamber. The superheater is made of 4 panels: the outer panels have 66 pipes each, and the middle panels have 57 pipes each. Pipes Ø 32x3.5 mm made of steel 20 are installed with a pitch of 36 mm. The inlet chambers of the ceiling superheater are made of Ø 219x16 mm from steel 20, the outlet chambers are Ø 219x20 mm from steel 20. The heating surface of the ceiling superheater is 109.1 m 2.
The pipes of the ceiling superheater are attached to special beams using welded strips (7 rows along the length of the ceiling superheater). The beams, in turn, are suspended using rods and hangers from the beams of the ceiling structures.
The screen superheater is located in the horizontal connecting gas duct of the boiler and consists of 32 screens located in two rows along the gas flow (the first row is radiation screens, the second is convective screens). Each screen has 28 coils made of pipes Ø 32x4 mm made of steel 12Х1МФ. The pitch between the pipes in the screen is 40 mm. The screens are installed with a pitch of 530 mm. The total heating surface of the screens is 420 m2.
The coils are fastened to each other using combs and clamps (6 mm thick, made of X20N14S2 steel), installed in two rows in height.
A horizontal type convective superheater is located in a lower convective shaft and consists of two stages: upper and lower. The lower stage of the superheater (the first along the steam flow) with a heating surface of 410 m 2 is counterflow, the upper stage with a heating surface of 410 m 2 is direct flow. The distance between the steps is 1362 mm (along the axes of the pipes), the height of the step is 1152 mm. The stage consists of two parts: left and right, each of which consists of 60 double three-loop coils located parallel to the front of the boiler. The coils are made of pipes Ø 32x4 mm (steel 12Х1МФ) and installed in a checkerboard pattern with steps: longitudinal - 50 mm, transverse - 120 mm.
The coils are supported by racks on support beams cooled by air. The spacing of the coils is carried out using 3 rows of combs and strips 3 mm thick.
Figure 5. Fastening of a convective pipe package with horizontal coils: 1 – support beams; 2 – pipes; 3 – racks; 4 – bracket.
The movement of steam through the superheater occurs in two immiscible flows, symmetrically relative to the axis of the boiler.
In each of the streams, the pair moves as follows. Saturated steam from the boiler drum through 20 pipes Ø 60x5 mm enters two collectors of a ceiling superheater Ø 219x16 mm. Next, the steam moves through the ceiling pipes and enters two outlet chambers Ø 219x20 mm, located at the rear wall of the convective flue. From these chambers, four pipes Ø 133x10 mm (steel 12Х1МФ), steam is directed to the inlet chambers Ø 133x10 mm (steel 12Х1МФ) of the outer screens of the convective part of the screen superheater. Next, to the outer screens of the radiation part of the screen superheater, then to the intermediate chamber Ø 273x20 (steel 12X1MF), from which pipes Ø 133x10 mm are directed to the four middle screens of the radiation part, and then to the four middle screens of the convective part.
After the screens, the steam enters a vertical desuperheater through four pipes Ø 133x10 mm (steel 12Х1МФ), after which it is directed through four pipes Ø 133x10 mm into two inlet chambers of the lower counterflow stage of the convective superheater. Having passed the lower stage coils in countercurrent, the steam enters two output chambers (the diameter of the inlet and outlet chambers is Ø 273x20 mm), of which four pipes Ø 133x10 mm are sent to a horizontal desuperheater. After the desuperheater, the steam enters through four Ø 133x10 mm pipes into the Ø 273x20 mm inlet manifolds of the upper stage. Having passed through the upper stage coils in direct flow, the steam enters the output collectors Ø 273x26 mm, from which it is directed through four pipes into the steam collection chamber Ø 273x26 mm.
Figure 6. Diagram of the steam superheater of the TGM-151-B boiler: a – diagram of ceiling panels and screens, b – diagram of convective pipe packages, 1 – drum, 2 – ceiling pipe panels (only one of the pipes is conventionally shown), 3 – intermediate manifold between ceiling panels and screens, 4 – screen, 5 – vertical desuperheater, 6 and 7 – lower and upper convective tube packages, respectively, 8 – horizontal desuperheater, 9 – steam collector, 10 – safety valve, 11 – air vent, 12 – superheated steam outlet .
4.2.3 Device for regulating the temperature of superheated steam
Control of the temperature of superheated steam is carried out in desuperheaters by injecting condensate (or feedwater) into the steam flow passing through them. On the path of each steam flow, two injection-type desuperheaters are installed: one vertical - behind the screen surface and one horizontal - behind the first stage of the convective superheater.
The desuperheater body consists of an injection chamber, a manifold and an outlet chamber. Injection devices and a protective jacket are located inside the housing. The injection device consists of a nozzle, a diffuser and a pipe with a compensator. The diffuser and the inner surface of the nozzle form a Venturi tube.
In the narrow section of the nozzle, 8 holes Ø 5 mm were drilled on desupercooler II and 16 holes Ø 5 mm on desupercooler I. Steam enters the injection chamber through 4 holes in the desuperheater body and enters the Venturi nozzle. Condensate (feed water) is supplied to the annular channel by a pipe Z 60x6 mm and injected into the cavity of the Venturi pipe through holes Ø 5 mm located around the circumference of the nozzle. After the protective jacket, the steam enters the outlet chamber, from where it is discharged through four pipes to the superheater. The injection chamber and outlet chamber are made of a pipe Ø G g 3x26 mm, the manifold is made of a pipe Ø 273x20 mm (steel 12Х1МФ).
Water economizer
The steel coil economizer is located in the lower gas duct behind the convective superheater packages (along the gas flow). The height of the economizer is divided into three packages, each 955 mm high, the distance between the packages is 655 mm. Each package is made of 88 double three-loop coils Ø 25x3.5 mm (steel20). The coils are located parallel to the front of the boiler in a checkerboard pattern (longitudinal pitch 41.5 mm, transverse pitch 80 mm). The heating surface of the water economizer is 2130 m2.
Figure 7. Sketch of an economizer with a double-sided parallel front arrangement of coils: 1 – drum, 2 – water bypass pipes, 3 – economizer, 4 – inlet collectors.
Air heater
The boiler unit is equipped with two regenerative rotating air heaters of type RVV-41M. The air heater rotor consists of a shell Ø 4100 mm (height 2250 mm), a hub Ø 900 mm and radial ribs connecting the hub to the shell, dividing the rotor into 24 sectors. The rotor sectors are filled with heating corrugated steel sheets (packing). The rotor is driven by an electric motor with a gearbox and rotates at a speed of 2 revolutions per minute. The total heating surface of the air heater is 7221 m2.
Figure 8. Regenerative air heater: 1 – rotor shaft, 2 – bearings, 3 – electric motor, 4 – packing, 5 – outer casing, 6 and 7 – radial and peripheral seal, 8 – air leakage.
Draft devices
To evacuate flue gases, the boiler unit is equipped with two double-suction smoke exhausters of type D-20x2. Each smoke exhauster is driven by an electric motor with a power of N = 500 kW, with a rotation speed of n = 730 rpm.
The performance and total pressure of smoke exhausters are given for gases at a pressure of 760 mm Hg. Art. and gas temperature at the entrance to the smoke exhauster is 200° C.
Nominal parameters at highest efficiency η=0.7
To supply the combustion air necessary for combustion into the furnace, boiler No. 11 is equipped with two blower fans (DV) of the VDN-18-II type with a capacity of Q = 170,000 m 3 /hour, a total pressure of 390 mm of water. Art. at a working environment temperature of 20° C. The fans of boiler No. 11 are driven by electric motors: left - 250 kW, rotation speed n = 990 rpm, right - 200 kW, rotation speed n = 900 rpm.
4.2.7 Safety valves
On boiler No. 11, two pulse safety valves are installed on the steam collection chamber. One of them - control - with an impulse from the steam collection chamber, the second - working - with an impulse from the boiler drum.
The control valve is set to operate when the pressure in the steam collection chamber increases to 105 kgf/cm 2 . The valve closes when the pressure drops to 100 kgf/cm2.
The working valve opens when the pressure in the drum increases to 118.8 kgf/cm 2 . The valve closes when the pressure in the drum drops to 112 kgf/cm2.
4.2.8 Burner devices
There are 8 gas-oil burners installed on the front wall of the combustion chamber, arranged in two tiers of 4 burners in each tier.
Combined burners are made of two-flow air.
Each burner of the lower tier is designed to burn a mixture of coke and blast furnace gases and fuel oil, and separate combustion of coke or blast furnace gases in the same burners. The coke blast mixture is fed through a Ø 490 mm manifold. Along the axis of the burner there is a pipe Ø 76x4 for installing an oil nozzle for mechanical atomization. The diameter of the embrasure is 1000 mm.
Each of the 4 upper tier burners is designed to burn natural gas and fuel oil. Natural gas is supplied through a Ø 206 mm manifold through 3 rows of holes Ø 6, 13, 25 mm. The number of holes is 8 in each row. The diameter of the embrasure is 800 mm.
4.2.9 Drum and separation devices
The boiler is equipped with a drum with a diameter of 1600 mm, drum wall thickness 100 mm, sheet steel
The boiler has a three-stage evaporation scheme. The first and second evaporation stages are organized inside the drum, the third in external cyclones. The first stage compartment is located in the middle of the drum, two second stage compartments are at the ends. Inside the drum, the water volumes of the salt compartments are separated from the clean compartment by partitions. The feed water for the salty compartments of the second stage is the boiler water of the clean compartment, which enters through the holes in the dividing intercompartment partitions. The feedwater for the third evaporation stage is the boiler water of the second stage.
Continuous blowing is carried out from the water volume of remote cyclones.
Feedwater entering the drum from the economizer is divided into two parts. Half of the water is directed through the pipes into the water space of the drum, the second half is introduced into the longitudinal distribution manifold, exits through the holes and spreads over the perforated sheet through which saturated steam passes. When steam passes through the feedwater layer, it is washed, i.e. purification of steam from the salts it contains.
After washing the steam, the feed water is drained through boxes into the water space of the drum.
The steam-water mixture, entering the drum, passes through 42 separation cyclones, of which: 14 are located on the front side of the drum, 28 are located on the rear side of the drum (including 6 cyclones stopped in the salt compartments of stepwise evaporation).
In cyclones, rough, preliminary separation of water and steam is carried out. The separated water flows into the lower part of the cyclones, under which trays are installed.
Directly above the cyclones there are louvered shields. Passing through these shields and through the perforated sheet, the steam is directed for final drying into the upper louvered shields, under which the perforated sheet is located. The middle level in the clean compartment is located 150 mm below its geometric axis. The upper and lower permissible levels are 40 mm above and below the average, respectively. The water level in salty compartments is usually lower than in the clean compartment. The difference in water levels in these compartments increases with increasing boiler load.
The phosphate solution is introduced into the drum into a clean staged evaporation compartment through a pipe located along the bottom of the drum.
The clean compartment has a pipe for emergency drainage of water in case of excessive rise in water level. In addition, there is a line with a valve connecting the space of the left remote cyclone to one of the lower chambers of the rear screen. When the valve is opened, boiler water moves from the salty compartment of the third stage into the clean compartment, due to which it is possible, if necessary, to reduce the salt content of water in the compartments. Leveling the salt content in the left and right salty compartments of the third stage of evaporation is ensured by the fact that a pipe comes out of each salty remote compartment, which directs boiler water to the lower screen chamber of the opposite salty compartment.
Figure 11. Scheme of three-stage evaporation: 1 – drum; 2 – remote cyclone; 3 – lower collector of the circulation circuit, 4 – steam generating pipes; 5 – lowering pipes; 6 – feed water supply; 7 – removal of purge water; 8 – water transfer pipe from the drum to the cyclone; 9 – steam transfer pipe from the cyclone to the drum; 10 – steam pipe from the unit; 11- intratympanic septum.
4.2.10 Boiler frame
The boiler frame consists of metal columns connected by horizontal beams, trusses, braces and is used to absorb loads from the weight of the drum, heating surfaces, lining, service bells, gas pipelines and other elements of the boiler. The columns of the boiler frame are rigidly attached to the iron foundation of the boiler, and the bases (shoes) of the columns are filled with concrete.
4.2.11 Brickwork
Sheets of lining are layers of fire-resistant and insulating materials that are attached using brackets and tie rods to a steel frame structure with cladding sheets.
In the panels, sequentially on the gas side, there are: layers of refractory concrete, sovelite mats, a layer of sealing coating. The thickness of the combustion chamber lining is 200 mm, in the area of the two lower economizer packages – 260 mm. The lining of the hearth in the lower part of the combustion chamber is made in a pipe manner. During thermal elongation of the screens, this lining moves along with the pipes. Between the movable and stationary parts of the combustion chamber lining there is an expansion joint sealed with a water seal (hydraulic seal). The lining has holes for manholes, hatches and hatches.
5. Safety precautions during work
On the territory of the power plant, students are subject to all safety and security rules in force at the enterprise.
Before the start of the tests, a representative of the enterprise briefs the students on the procedure for conducting the test and on safety rules, which are recorded in the relevant documents. During tests, students are prohibited from interfering with the actions of maintenance personnel, turning off devices on the control panel, opening peepholes, hatches, manholes, etc.
Bibliography
- Sidelkovsky L.N., Yurenev V.N. Boiler installations of industrial enterprises: Textbook for universities. – 3rd ed., revised. – M.: Energoatomizdat, 1988. – 528 p., ill.
- Kovalev A.P. and others. Steam generators: a textbook for universities / A.P. Kovalev, N.S. Leleev, T.V. Vilensky; Under general ed. A. P. Kovalev. – M.: Energoatomizdat, 1985. – 376 p., ill.
- Kiselev N.A. Boiler installations, Training manual for preparation. workers in production - 2nd ed., revised. and additional – M.: Higher School, 1979. – 270 pp., ill.
- Deev L.V., Balakhnichev N.A. Boiler installations and their maintenance. Practical classes for vocational schools. – M.: Higher School, 1990. – 239 p., ill.
- Meyklyar M.V. Modern boiler units TKZ. – 3rd ed., revised. and additional – M.: Energy, 1978. - 223 pp., ill.
The TGM-84 boiler unit is designed according to a U-shaped layout and consists of a combustion chamber, which is an ascending gas duct, and a lower convective shaft, divided into 2 gas ducts. There is practically no transitional horizontal gas duct between the firebox and the convective shaft. A screen steam superheater is located in the upper part of the firebox and the rotating chamber. In a convective shaft, divided into 2 gas ducts, a horizontal steam superheater and a water economizer are placed in series (along the flow of gases). Behind the water economizer there is a rotating chamber with ash collection bins.
Two regenerative air heaters connected in parallel are installed behind the convective shaft.
The combustion chamber has the usual prismatic shape with dimensions between the axes of the pipes 6016 * 14080 mm and is divided by a two-light water screen into two half-fireboxes. The side and rear walls of the combustion chamber are shielded with evaporation pipes with a diameter of 60 * 6 mm (steel-20) with a pitch of 64 mm. The side screens in the lower part have slopes towards the middle in the lower part at an angle of 15 to the horizontal and form a “cold” floor.
The two-light screen also consists of pipes with a diameter of 60 * 6 mm with a pitch of 64 mm and has windows formed by pipe routing to equalize the pressure in the half-furnaces. The screen system is suspended from the metal structures of the ceiling using rods and has the ability to freely fall down during thermal expansion.
The ceiling of the combustion chamber is made horizontal and shielded by the pipes of the ceiling superheater.
A combustion chamber equipped with 18 oil burners, which are located on the front wall in three tiers. The boiler has a drum with an internal diameter of 1800 mm. The length of the cylindrical part is 16200 mm. In the boiler drum, separation and steam washing with feed water is organized.
Schematic diagram of steam superheaters
The superheater of the TGM-84 boiler is radiation-convective in nature of heat perception and consists of the following three main parts: radiation, screen or semi-radiation and convective.
The radiation part consists of a wall and ceiling superheater.
The semi-radiation superheater consists of 60 standardized screens. The horizontal type convective superheater consists of 2 parts located in 2 gas ducts of the lower shaft above the water economizer.
A wall-mounted superheater is installed on the front wall of the combustion chamber, made in the form of six transportable blocks of pipes with a diameter of 42*55 (steel 12*1MF).
The outlet chamber of the ceiling substation consists of 2 manifolds welded together, forming a common chamber, one for each semi-furnace. The output chamber of the combustion chamber is one and consists of 6 manifolds welded together.
The inlet and outlet chambers of the screen superheater are located one above the other and are made of pipes with a diameter of 133 * 13 mm.
The convective superheater is made according to a Z-shaped design, i.e. steam enters from the front wall. Each substation consists of 4 single-pass coils.
Devices for regulating the superheat temperature of steam include a condensing unit and injection desuperheaters. Injection desuperheaters are installed in front of the screen superheaters in the screen section and in the convective superheater section. When operating on gas, all desuperheaters operate; when operating on fuel oil, only the one installed in the convective subcooler section.
The steel coil water economizer consists of 2 parts, located in the left and right gas ducts of the convection shaft.
Each part of the economizer consists of 4 packages in height. Each package contains two blocks, each block contains 56 or 54 four-way coils made of pipes with a diameter of 25 * 3.5 mm (steel 20). The coils are located parallel to the front of the boiler in a checkerboard pattern with a pitch of 80 mm. The economizer collectors are placed outside the convective shaft.
The boiler is equipped with 2 regenerative rotating air heaters RVP-54.
Explanation TGM - 84 - Taganrog gas-oil boiler, manufactured in 1984.
The TGM-84 boiler unit is designed according to a U-shaped layout and consists of a combustion chamber, which is an ascending gas duct, and a lower convective shaft, divided into two gas ducts.
There is practically no transitional horizontal gas duct between the firebox and the convective shaft. A screen steam superheater is located in the upper part of the firebox and the rotating chamber. In a convective shaft, divided into two gas ducts, a horizontal steam superheater and a water economizer are placed in series (along the flue gases). Behind the water economizer there is a rotating chamber with ash collection bins.
Two regenerative air heaters connected in parallel are installed behind the convective shaft.
The combustion chamber has the usual prismatic shape with dimensions between the axes of the pipes 6016 14080 mm and is divided by a two-light water screen into two half-fireboxes. The side and rear walls of the combustion chamber are shielded by evaporation pipes with a diameter of 60 6 mm (steel 20) with a pitch of 64 mm. The side screens in the lower part have slopes towards the middle, in the lower part at an angle of 15 to the horizontal, and form a “cold floor”.
The two-light screen also consists of pipes with a diameter of 60 6 mm with a pitch of 64 mm and has windows formed by pipe routing to equalize the pressure in the half-furnaces. The screen system is suspended from the metal structures of the ceiling using rods and has the ability to freely fall down during thermal expansion.
The ceiling of the combustion chamber is made of horizontal and shielded pipes of the ceiling superheater.
The combustion chamber is equipped with 18 oil burners, which are located on the front wall in three tiers.
The boiler has a drum with an internal diameter of 1800 mm. The length of the cylindrical part is 16200 mm. Separation and washing of steam with feed water is organized in the boiler drum.
The superheater of the TGM-84 boiler is radiation-convective in nature and consists of the following three main parts: radiation, screen (or semi-radiation) and convective.
The radiation part consists of a wall and ceiling superheater.
Semi-radiation steam superheater made of 60 standardized screens.
The horizontal type convective superheater consists of two parts located in two gas ducts of the lower shaft above the water economizer.
A wall-mounted superheater is installed on the front wall of the combustion chamber, made in the form of six transportable blocks of pipes with a diameter of 42x5.5 mm (item 12Х1МФ).
The inlet chamber of the ceiling superheater consists of two collectors welded together, forming a common chamber, one for each half-firebox. The outlet chamber of the ceiling superheater is one and consists of six collectors welded together.
The inlet and outlet chambers of the screen superheater are located one above the other and are made of pipes with a diameter of 133x13 mm.
The convective superheater is made according to a z-shaped design, i.e. steam enters from the front wall. Each package consists of 4 single-pass coils.
Devices for regulating steam superheat temperature include: condensing unit and injection desuperheaters. Injection desuperheaters are installed in front of the screen superheaters in the screen section and in the convective superheater section. When the boiler is operating on gas, all desuperheaters operate; when operating on fuel oil, only the convective superheater installed in the cut-out.
The steel coil water economizer consists of two parts located in the left and right flue ducts of the convection shaft.
Each part of the economizer consists of 4 packages in height. Each package contains two blocks, each block contains 56 or 54 four-way coils made of pipes with a diameter of 25x3.5 mm (steel 20). The coils are located parallel to the front of the boiler in a checkerboard pattern with a pitch of 80 mm. The economizer collectors are located outside the convective shaft.
The boiler is equipped with two regenerative rotating air heaters RVP-54. The air heater is placed outside and consists of a rotating rotor enclosed inside a stationary housing. The rotor rotates by an electric motor with a gearbox at a speed of 3 rpm. Reducing cold air suction into the air heater and air flows from the air to the gas side is achieved by installing radial and peripheral seals.
The boiler frame consists of metal columns connected by horizontal beams, trusses and braces and is used to absorb loads from the weight of the drum, heating surfaces, lining, service areas, gas ducts and other elements of the boiler. The frame is made welded from rolled profiles and sheet steel.
To clean the heating surfaces of the convective steam superheater and water economizer, a shot blasting unit is used, which uses the kinetic energy of freely falling pellets of 3-5 mm in size. Gas pulse cleaning can also be used.
