RU2216640C2 - Co-generative modular heat power station with internal combustion engine and additional burner assembly - Google Patents

Abstract

FIELD: power engineering. SUBSTANCE: proposed heat power station includes at least one engine-generator plant, with mainly liquid-cooled internal combustion engine and at least one electric fan plant to supply air to engine-generator plant. Module is formed by engine-generator and electric fan plants placed in common heat insulating housing which is provided with heat intake from side of generator, preferably along its axis and delivery pipeline from opposite side. Air intake and gas exhaust ducts of internal combustion engine are brought out of the housing. Other structural part of heat power station is "thermal column" formed by waste-heat recovery boiler with mixing chamber connected to its gas inlet and engine- generator plant installed in head part and connected to inlet device. Gas exhaust duct of internal combustion engine is connected to other inlet device of chamber. Delivery pipeline of module is connected to air inlet of engine-generator plant through distributing device kinematically coupled with fuel metering element of engine- generator plant. Distributing device is connected also at least to one additional hot air consumer. Used as said consumer can be mixing chamber of "thermal column", water-to-air heat exchanger in hot-water supply system, building ventilation system, etc. These consumers are placed in operation at partial duties with engine-generator plant operating. Proposed design of module makes it possible to suppress, practically completely radiation losses of internal combustion engine, generator and "thermal column". EFFECT: increased efficiency of heat power station up to 90-95%. 8 cl, 2 dwg

Description

 The invention relates to the field of power engineering, and in particular to cogeneration modular thermal power plants (TPPs) mainly for domestic purposes with an internal combustion engine and an additional burner device.

 Known cogeneration modular TPP [international application (WO) 87/03933 according to MKI 4 F 02 G 5/00 dated 02.07.87], containing the engine-generator set with a power generator and a piston internal combustion engine having air inlet and gas outlet tracts. In the latter there is a waste heat boiler. The module forms the listed and other equipment, placed in a sealed insulated casing with gas-air ducts brought out. The module does not contain an additional burner.

 The casing is almost completely filled with liquid coolant, the circulation of which through the openings in the casing along the circuit of thermal energy consumers provides the possibility of efficient use of the released thermal energy, including radiation through the internal combustion engine and generator surfaces, which increases the overall efficiency up to 5-7 points.

 In another structurally similar technical solution [international application (WO) 88/03989 in accordance with MKI 4 F 02 G 5/04 of 06/20/08] instead of filling the casing volume with liquid, the module uses a liquid heat exchanger connected to the ICE cooling jacket and to the external the circuit of consumers of thermal energy, and the entire free space of the casing around the engine is filled with heat-absorbing material.

 The most significant drawback of both known solutions is their reduced relative thermal power (the ratio of the nominal values of the thermal electric capacities of a cogeneration TPP with an internal combustion engine), not exceeding 1.2-1.6.

 At the same time, it is known [Boretsky B.M., Vlasov L.I. Comparative analysis of basic indicators of cogeneration thermal power plants with various heat production systems. "Engine", S. -Pb., 2000, 3, p. 13-15] that cogeneration TPPs for domestic needs, at least in Russia, should have a higher ratio of nominal values of thermal and electric capacities at the level of 2.5-4.5, which is achieved in the best way by using an additional burner in TPPs with ICE device installed in front of the recovery boiler.

 Known cogeneration modular TPP [application of Germany 3805690 according to MKI 4 F 02 G 5/04 of 08/31/89], containing at least one engine-generator set with a power generator and a piston internal combustion engine with air inlet and gas outlets, an electric fan installation and a “heat column "

 The "heat pipe" is formed from a waste heat boiler with a mixing chamber connected to its gas inlet, which has input devices, one of which is connected to an additional burner device (DGU), and to the other gas exhaust path of the internal combustion engine. DGU has a metering body for fuel supply and an air inlet connected to an electric fan installation. In front of the DGU air inlet, a water-air heat exchanger is installed, which is included in the internal combustion engine's liquid cooling system. The module forms the actual engine-generator set.

 This technical solution, adopted as a prototype, allows to obtain high values of relative thermal power in TPPs, and the heat of the cooling DOS liquid transferred to consumers, fully or partially, comes from the recovery boiler by transferring it to the air flow pumped into the DGU of the “heat column” .

 A disadvantage of the known TPP is a reduced total efficiency due to radiation losses of the internal combustion engine and the generator.

 The aim of the invention is to increase the efficiency of a cogeneration TPP with internal combustion engines and an additional burner device.

 This goal is achieved by the fact that at TPP at least one engine-generator set with a power generator and a piston engine with an air inlet and gas outlet tracts, as well as a "heat pipe" formed by at least a single-stage recovery boiler with connected to its gas inlet by the mixing chamber and an additional burner device connected to the input device of the mixing chamber. The gas exhaust path of the internal combustion engine is connected to another input device of the camera.

 DGU has a metering body for fuel supply and an air inlet connected with at least one electric fan installation, mainly intended for air supply to the DGU.

 The cogeneration TPP is distinguished by the fact that the module is formed by the engine-generator and electric fan units, placed in a common heat-insulated casing, which has an air intake on the side of the generator, preferably along its axis, and the discharge pipe on the opposite side. The air intake and gas exhaust paths of the internal combustion engine are brought out of the casing.

 The discharge pipe through a switchgear kinematically connected with the metering body of the fuel supply to the diesel generator set is connected to the air inlet of the diesel generator set and at least one additional consumer of hot air. This ensures, in particular, the possibility of stabilizing the performance of the fan unit with variable power of the diesel generator set and stabilizing the blowing mode of the engine-generator unit.

 An essential feature of the proposed TPP is the possibility of highly efficient use of both liquid and air cooling in the engine module.

 The module can use electric fan installations of both axial and centrifugal (snail) types.

 It is advisable to place the axial fan in the casing air collector and use it in those cases when the heating system requires constant heating provided by the radiation of the "heat column".

 For maintenance-free TPPs, where heating can only be requested periodically and for short periods, it is advisable to use a centrifugal fan installed in the module, installed at the end of the engine, opposite the generator, and connected to the discharge pipe by the outlet of the cochlea.

 The vacuum created in such a module allows the radiation of the “heat column” to be regenerated if it is placed in its own casing with one end open to the atmosphere and the other end using a pipe connected to the module’s internal cavity near the fan inlet. The pipeline should be equipped with a valve to regulate flows and the possibility of "turning on" the heating of the TPP premises. To ensure maximum heating of the air drawn in by the fan, it is also advisable to use an adjustable throttle valve in the air intake of the module casing. Such a TPP potentially has the highest efficiency of using fuel energy for the needs of consumers of combined energy among all known cogeneration TPPs, because the air-laminating curtain under the casing has the best heat-insulating properties in comparison with liquid or solid filling of voids under the casing (as suggested in the analogues).

 As an additional consumer of hot air, a mixing chamber may be used connected by one or more additional input devices to the dispenser of the discharge pipe. Such a connection, in particular, is necessary for diluting the high-temperature combustion products of diesel generator sets during periods of routine shutdowns of internal combustion engines. During normal operation of the TPP, it is advisable to introduce air at the end sections of the mixing device for afterburning gaseous products of incomplete combustion of fuel.

 As an additional consumer of hot air, a water-air heat exchanger installed as at least a pre-heater of cold water in the hot water supply system (DHW) from a TPP can also be used.

 Finally, as an additional consumer of hot air, the building's ventilation system can be used, inside which a thermal power station is built.

 In the case of completing the TPP with several proposed modules, all discharge pipelines are connected to one common distribution device, and the gas exhaust paths of the internal combustion engine are connected to the input devices of the mixing chamber.

 In FIG. 1 shows a schematic diagram of a cogeneration single-module TPP made in a heated version with an internal combustion engine of liquid combined cooling with an axial fan.

 In FIG. Figure 2 shows a schematic diagram of a cogeneration single-module TPP made in an unheated version with an internal combustion engine of liquid cooling at the expense of consumers of thermal energy.

 An engine-generator set with an internal combustion engine 1 of liquid cooling paired with a power generator 2 and an electric fan unit 3 or 4, placed in a heat-insulated casing 5 or 6, form a module 7 or 8.

 The waste heat boiler 9 with a mixing chamber 10 connected to its gas inlet and an additional burner device 11 form a “heat column” 12. The diesel generator set 11 is connected to the input device 13, and the gas exhaust path 15 of the internal combustion engine 1 connected to the outside of the casing 5 is connected to another input device 14 or 6.

 The casing 5 or 6 has an air intake 16 or 17 coaxial with the generator 2, and a fan 3 is installed in the air intake 16. At the opposite end of the casing 5 or 6 a discharge pipe 18 or 19 is connected, and the inlet of the pipe 19 is connected to the outlet of the scroll of the centrifugal fan 4.

 The discharge pipe 18 or 19 is connected to a distribution device 20, which has a gas connection with the air inlet 21 of the diesel generator set 11 and kinematic connection with the metering body of the fuel supply 22 in the diesel generator set 11.

 A waste heat boiler 9 is included in the consumer circulation heating circuit 23. In the return line 24 of the circuit 23, a liquid cooling heat exchanger 25 is installed, which is included in the liquid circulation circuit 26 through the cooling jacket 27 of the internal combustion engine 1.

 In the performance of the TPP according to the embodiment of FIG. 1, an air-cooled heat exchanger 29 connected to the inside of the casing 5 is connected to the cooling jacket 27 in parallel with the heat exchanger 25 through the valve system 28.

 A water-to-water heat exchanger 31 of the hot water supply system 32 is installed in the discharge line 30 of the hot water system 32. Water is taken into the hot water supply system 32 through a water-air heat exchanger 34 connected by a pipe 35 to the distribution device 20.

 In the performance of the TPP according to the embodiment of FIG. 2, the “heat pipe” 12 is placed in a casing 36, one of the ends of which is open to the atmosphere, and the other is connected by a pipe 37 to a valve 38 with an internal cavity of the casing 6 near the fan 4.

 The dashed lines show the connections of the switchgear 20 with different sections of the mixing chamber 10.

 The proposed TPP works as follows.

 At the maximum thermal load of the TPP, the fan capacity 3 or 4 corresponds to the maximum required air supply of DGU 11 with some excess necessary for additional air supply to the mixing chamber 10 in front of the recovery boiler 9. At the same time, the switchgear 20 cuts off all other air consumers. This ensures that losses to the fan drive are minimized. The radiator 29 in figure 1 using valves 28 is disconnected from the cooling jacket 27 of the internal combustion engine 1.

 Heat flows from the internal combustion engine 1 and diesel generator set 11 through heat exchangers 9 and 25 enter the heating circuit 23, part of the heat from which is supplied through the heat exchanger 31 to the hot water supply.

 The flow of air drawn in through the air intake 16 or 17 into the casing 5 or 6 in a low-speed, low-turbulent (disturbance from poorly streamlined bodies) mode first flows around (cooling) the generator 2, and then the ICE 1. As the air curtain moves, the air curtain warms up and the temperature drop between ICE 1 decreases ( coolant in the jacket 27) and air, which reduces the radiation intensity of the internal combustion engine.

 As a result, an additive effect is created, accompanied by a decrease in fuel consumption in the diesel generator set 11 and due to the preheating of the air entering the diesel generator set 11 from the discharge pipe 18 or 19, and an increase in the fraction of heat transferred from the internal combustion engine 1 by the coolant and transferred to consumers through the heat exchanger 25.

 Losses through the heat-insulated walls of the casing 5 or 6 are negligible both due to the gradual heating of the air curtain near the casing walls along the module 7 or 8 along with the low values of the heat transfer coefficient from air to the walls.

 With a decrease in the heating load in the circuit 23, the fuel supply to the diesel generator set 11 automatically decreases with the help of the metering unit 22 and the air supply to the inlet 21 is proportionally reduced with the help of a distribution device 20, which simultaneously communicates the pipeline 35 with the discharge pipe 18 or 19, thereby including the water-air supply heat exchanger 34 for domestic hot water. This reduces (up to zero) the load on the heat exchanger 31, which leads to an additional effect of reducing fuel consumption in the diesel generator set 11.

 In the embodiment of the TPP according to Fig. 1, a complete shutdown of the heating circuit 23 is allowed (when the diesel engine 11 is turned off), if the built-in radiator 29 is connected to the cooling jacket 27 of the internal combustion engine 1 instead of the heat exchanger 25 using the valve system 28. The heat of cooling of the internal combustion engine 1 by the consumer (hot air consumer ) in this case, there may be a heat exchanger 34 in the domestic hot water system, as well as the ventilation system of the building (not shown).

The equipment of thermal power plants according to the variant of figure 2 is not intended for all seasonal work, but serves for maintenance-free operation in the heating period in an unheated room. A “heat column” 12, all elements of which are thermally insulated and have a temperature of at least 80 ^° C on the surface, surrounded by a casing 36 with an appropriate gap, which is connected to the casing 6 of module 8, allows the air coming from fan 4 to DGU 11 to be heated as much as possible (and other devices) and reduce fuel consumption. For routine maintenance at such a thermal power plant, they include heating the room by shutting off the valve 38. To configure the economical operation of the thermal power plant without its own heating, in addition to the valve 38, it is advisable to use an adjustable throttle valve (not shown) in the air intake 17 of the casing 6 of module 8.

 The casing 5 or 6 of the module 7 or 8, as well as the casing 36 may have removable panels for easy access to devices subject to routine maintenance or replacement during operation.

 The proposed simple technical solution for the design of a module for a cogeneration TPP with internal combustion engine and an additional burner device allows to increase the total efficiency of TPPs by 5 ... 7 points to the level of 90 ... 95%.

Claims (8)

 1. A cogeneration modular thermal power plant with an internal combustion engine (ICE) and an additional burner device comprising at least one engine-generator set with a power generator and a piston ICE with air inlet and gas outlets, at least one electric fan installation and a heat column formed by at least a one-stage recovery boiler with a mixing chamber connected to the gas inlet having input devices, one of which is connected to a gas outlet the internal combustion engine path, and to the other, an additional burner device with a fuel metering body and an air inlet connected to an electric fan installation, characterized in that the module is formed by a motor-generator and electric fan installation, placed in a common heat-insulated casing, which is preferably on the generator side, its axis, has an air intake, and on the opposite side - a discharge pipe connected via a distribution device to the air inlet of the additional burner and at least one additional consumer input air intake tract housing ICE withdrawn outwardly, and the dispenser is kinematically connected with the fuel metering body.  2. Cogeneration modular thermal power plant according to claim 1, characterized in that an axial fan integrated in the casing air intake is used as an electric fan installation.  3. The cogeneration modular thermal power plant according to claim 1, characterized in that a centrifugal fan installed behind the internal combustion engine in such a way that the outlet of the cochlea of the fan is connected to the discharge pipe is used as the electric ventilation installation.  4. Cogeneration modular thermal power plant according to claim 3, characterized in that the "thermal column" is placed in a casing, one end of which is open to the atmosphere, and the other is connected by a pipeline to the internal cavity of the module near the fan inlet.  5. Cogeneration modular thermal power plant according to claim 1, characterized in that the mixing chamber of the "thermal column" is used as an additional consumer.  6. Cogeneration modular power plant according to claim 1, characterized in that a water-air heat exchanger is used as an additional consumer.  7. Cogeneration modular thermal power plant according to claim 1, characterized in that the ventilation system of the building is used as an additional consumer.  8. The cogeneration modular thermal power plant according to claim 1, characterized in that when it is equipped with several of the indicated modules, all the discharge pipelines are connected to one common distribution device, and the gas exhaust paths of the internal combustion engine are connected to the input devices of the mixing chamber.

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