Composite back pressure type combined heat and power generation device

Abstract

The invention discloses a composite back pressure type combined heat and power generation device, and particularly relates to the technical field of energy conversion and comprehensive energy utilization, the composite back pressure type combined heat and power generation device comprises a high-temperature and ultrahigh-pressure boiler and a high-pressure back pressure type steam turbine, and a pipeline is connected between the high-temperature and ultrahigh-pressure boiler and the high-pressure back pressure type steam turbine; a boiler low-temperature reheater, a production steam user and a deaerator are further arranged at the output end of the high-pressure back-pressure steam turbine, a deoxidizing water tank is further fixed to the output end of the deaerator, and a boiler water feeding pump is further arranged on the outer surface of the deoxidizing water tank. According to the composite back pressure type combined heat and power generation device, the design of high energy, high utilization and low energy and low utilization is adopted, the heating temperature serves as the boundary of steam heat energy, steam heat energy with the heating temperature higher than the heating temperature is completely converted into electric energy, heat energy with the heating temperature lower than the heating temperature is used for heating, and electric energy conversion is greatly improved; and the application range of the generator is expanded.

Description

Technical Field

[0001] The invention relates to the technical field of energy conversion and comprehensive energy utilization, and in particular to a composite back-pressure cogeneration device. Background Art

[0002] With the rapid development of solar and wind power generation in my country, thermal power generating units have gradually shifted from meeting basic power generation loads to taking on peak load regulation tasks. However, in northern my country, heating units account for about 70% of thermal power generating units. The "heat-to-power" operation mode limits the peak load regulation capacity of the units, resulting in serious problems of wind and solar power abandonment during the low load period of the winter heating period. If the thermal power plant adopts thermal-electric decoupling technology, the peak load regulation capacity of the units can be maximized while meeting the heating heat load, which can solve the problem of the power grid's absorption of wind power and photovoltaic power generation.

[0003] The prior art cannot deoxygenate and heat the condensed water again during use, resulting in relatively low working efficiency of the device. Summary of the invention

[0004] The main purpose of the present invention is to provide a composite back-pressure cogeneration device, which can effectively solve the problem of relatively low working efficiency of the device.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A composite back-pressure cogeneration device, comprising a high-temperature and ultra-high-pressure boiler;

[0007] A high-pressure back-pressure steam turbine, wherein a pipeline is connected between the high-temperature and ultra-high-pressure boiler and the high-pressure back-pressure steam turbine, and a boiler low-temperature reheater, a production steam user and a deaerator are also provided at the output end of the high-pressure back-pressure steam turbine, a deaerator water tank is also fixed at the output end of the deaerator, and a boiler feed water pump is also provided on the outer surface of the deaerator water tank;

[0008] A low-pressure reheat steam turbine, wherein the output end of the low-pressure reheat steam turbine is connected to a steam turbine generator via a detachable coupling;

[0009] A high-pressure heater, wherein a pipeline is connected between the high-pressure heater and the high-pressure back-pressure steam turbine;

[0010] A heating network heater, wherein a heater drain pump is fixed to the output end of the heating network heater.

[0011] Preferably, a pipeline is connected between the low-pressure reheat steam turbine and the boiler low-temperature reheater.

[0012] Preferably, pipelines are connected between the high-pressure heater and the boiler feed water pump, the deaerator, the deaerator water tank, and the high-temperature and ultra-high-pressure boiler.

[0013] Preferably, a pipeline is connected between the heating network heater and the low-pressure reheat steam turbine.

[0014] Preferably, the low-pressure heater is connected to the heater drain pump, the heating network heater, and the low-pressure reheat steam turbine via pipelines.

[0015] Preferably, a plurality of the high-pressure heaters are arranged in series, and a plurality of the low-pressure heaters are arranged in series.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention adopts a design of two steam turbines to improve the power generation capacity of the device. At the same time, two steam turbines are used to generate electricity in the heating season, and one steam turbine is used to generate electricity in the non-heating season, which expands the use range of the steam turbine generator. The design of high energy and high use and low energy and low use is adopted, so that the steam thermal energy is divided by the heating temperature. The steam thermal energy above the heating temperature is fully converted into electrical energy, and the thermal energy below the heating temperature is used for heating, which greatly improves the conversion of electrical energy.

[0018] 2. The present invention adopts a design of a detachable coupling. In the heating season, two steam turbines are used to drive a generator to generate electricity, thereby improving the power generation capacity. In the non-heating season, a high-pressure back-pressure steam turbine is used to generate electricity, thereby expanding the use range of the generator.

[0019] 3. The present invention adopts a boiler low-temperature reheater to heat the steam exhausted from the high-pressure back-pressure steam turbine, and then transmits it to the low-pressure reheat steam turbine, which can improve the heat conversion efficiency when the high-pressure back-pressure steam turbine is in use and improve the energy utilization rate when the device is in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0021] In the figure: 1. High-temperature and ultra-high-pressure boiler; 2. High-pressure back-pressure steam turbine; 3. Steam turbine generator; 4. Low-pressure reheat steam turbine; 5. Removable coupling; 6. Boiler low-temperature reheater; 7. Production steam user; 8. Deaerator; 9. Deaerator water tank; 10. Boiler feed pump; 11. High-pressure heater; 12. Heating network heater; 13. Heater drain pump; 14. Low-pressure heater. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0023] like Figure 1As shown, a composite back-pressure cogeneration device comprises a high-temperature and ultra-high-pressure boiler 1, which generates steam when in operation;

[0024] A high-pressure back-pressure steam turbine 2 is connected with the high-temperature ultra-high-pressure boiler 1 and the high-pressure back-pressure steam turbine 2 by a pipeline. The design of the high-pressure back-pressure steam turbine 2 can meet the heat demand of two different purposes at the same time, and can also meet the heating demand or the production steam demand alone, so that the steam generated by the high-temperature ultra-high-pressure boiler 1 can enter the high-pressure back-pressure steam turbine 2 through the pipeline. The high-pressure back-pressure steam turbine 2 discharges the steam from the tail after doing work. The output end of the high-pressure back-pressure steam turbine 2 is also provided with a boiler low-temperature reheater 6 and a production steam user 7 (wherein, the steam user 7 is a user of steam). The high-pressure back-pressure steam turbine 2 supplies the discharged low-pressure steam to the production steam user 7 and the deaerator 8. During the heating season, the steam used for heating will enter the boiler low-temperature reheater 6 for reheating. When the deaerator 8 is in use, the boiler supplementary water and the production return water enter the deaerator 8, and the deaerator 8 performs a deoxygenation operation on the deaerator 8. A deoxygenation water tank 9 is also fixed at the output end of the deaerator 8. A boiler feed water pump 10 is also provided on the outer surface of the deoxygenation water tank 9. The deoxygenation water tank 9 is used to store the deoxygenated water. At the same time, the deaerator 8 can also heat and deoxygenate the water in the deoxygenation water tank 9;

[0025] The low-pressure reheat steam turbine 4 is connected to the low-temperature reheater 6 of the boiler by a pipeline, so that the steam generated by the low-temperature reheater 6 of the boiler can provide power to the low-pressure reheat steam turbine 4, so that the low-pressure reheat steam turbine 4 can work. At the same time, the high-pressure back-pressure steam turbine 2 transmits the exhaust steam to the low-temperature reheater 6 of the boiler, and then uses the low-temperature reheater 6 of the boiler to heat the steam, and then transmits it to the low-pressure reheat steam turbine 4. The steam exhausted by the high-pressure back-pressure steam turbine 2 enters the low-pressure reheat steam turbine 4 to do work, so that the heat conversion efficiency of the high-pressure back-pressure steam turbine 2 reaches the limit, the energy utilization rate is improved, and the low-pressure reheat steam turbine The output end of the low-pressure reheat steam turbine 4 is connected to the steam turbine generator 3 through a detachable coupling 5, so that the low-pressure reheat steam turbine 4 can drive the steam turbine generator 3 to rotate when working, so that the steam turbine generator 3 can generate electricity. At the same time, the design of the detachable coupling 5 is adopted, so that the device can control the connection between the low-pressure reheat steam turbine 4 and the steam turbine generator 3 when in use. When heating is not needed and only industrial steam is used, the detachable coupling 5 disconnects the low-pressure reheat steam turbine 4 from the steam turbine generator 3, and only the high-pressure back-pressure steam turbine 2 is used to drive the steam turbine generator 3 to work, which can meet the most basic pressure requirement for heating and supply heating use, so that the fuel can reach the step-level limit utilization.

[0026] At the same time, the input shaft of the steam turbine generator 3 is connected to the high-pressure back-pressure steam turbine 2 and the low-pressure reheat steam turbine 4, so that the high-pressure back-pressure steam turbine 2 and the low-pressure reheat steam turbine 4 work together and drive the steam turbine generator 3, allowing the steam turbine generator 3 to generate electricity, thereby improving the power generation capacity of the device. During the heating season, the high-pressure back-pressure steam turbine 2 and the low-pressure reheat steam turbine 4 are used to generate electricity at the same time, and the high-pressure back-pressure steam turbine 2 is used to generate electricity during the non-heating season, thereby expanding the use scope of the steam turbine generator 3. The design of the high-pressure back-pressure steam turbine 2 and the low-pressure reheat steam turbine 4 is adopted, and high energy is used for high use and low energy is used for low use, so that the steam thermal energy is limited by the heating temperature, and the steam thermal energy above the heating temperature is fully converted into electrical energy, and the thermal energy below the heating temperature is used for heating, thereby greatly improving the conversion of electrical energy.

[0027] A high-pressure heater 11 is connected to the high-pressure back-pressure steam turbine 2 by a pipeline. In order to improve the working efficiency of the device, the high-pressure back-pressure steam turbine 2 extracts part of the higher-pressure steam from the middle part and heats it through the high-pressure heater 11. Pipes are connected between the high-pressure heater 11 and the boiler feed water pump 10, the deaerator 8, the deaeration water tank 9, and the high-temperature and ultra-high-pressure boiler 1. The water from the deaerators 8 and 19 is pressurized and then transmitted to the high-temperature and ultra-high-pressure boiler 1 to regenerate steam. The drainage of the high-pressure heater 11 will also return to the deaeration water tank 9 and be deoxygenated and heated again by the deaerator 8.

[0028] A heating network heater 12 is provided. A pipeline is connected between the heating network heater 12 and the low-pressure reheat steam turbine 4, so that the ultra-low back pressure exhaust steam after the low-pressure reheat steam turbine 4 works can enter the heating network heater 12 for heat exchange and cooling. The water of the heating network heater 12 when in use comes from the low-temperature return water of the heating station, and then the heated water is transmitted to the heating station for heating. A heater drain pump 13 is fixed to the output end of the heating network heater 12, so that the condensed water discharged from the heating network heater 12 is pressurized by the heater drain pump 13. The condensed water pressurized by the heater drain pump 13 can be transmitted to the deaerator water tank 9, so that the deaerator 8 heats and deoxidizes it.

[0029] The low-pressure heater 14 is connected to the heater drain pump 13, the heating network heater 12, and the low-pressure reheat steam turbine 4 by pipelines. The condensed water pressurized by the heater drain pump 13 is transmitted to the low-pressure heater 14, wherein the low-pressure heater 14 is one of the necessary measures to improve the efficiency of the thermal system. The main heating steam of the low-pressure heater 14 comes from the steam extraction of the middle part of the low-pressure reheat steam turbine 4. The drain of the low-pressure heater 14 can be returned to the heating network heater 12, and then returned to the deaeration water tank 9 with the condensed water transmitted by the heater drain pump 13. All the water flowing into the deaeration water tank 9 is deoxygenated and heated by the deaerator 8. The steam is heated to an appropriate temperature and then pressurized by the boiler feed pump 10, and then heated to the required temperature of the boiler through the high-pressure heater 11.

[0030] There may be multiple high-pressure heaters 11 and low-pressure heaters 14 connected in series.

[0031] It should be noted that the specific installation methods, circuit connection methods and control methods of the high-temperature and ultra-high-pressure boiler 1, the high-pressure back-pressure steam turbine 2 and the steam turbine generator 3 in the present invention are all conventional designs and are not elaborated in detail in the present invention.

[0032] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A composite back-pressure cogeneration device, comprising a high-temperature and ultra-high-pressure boiler (1); A high-pressure back-pressure steam turbine (2), wherein a pipeline is connected between the high-temperature and ultra-high-pressure boiler (1) and the high-pressure back-pressure steam turbine (2), and the output end of the high-pressure back-pressure steam turbine (2) is also provided with a boiler low-temperature reheater (6), a production steam user (7) and a deaerator (8), and a deaerator (9) is also fixed to the output end of the deaerator (8), and a boiler feed water pump (10) is also provided on the outer surface of the deaerator (9); A low-pressure reheat steam turbine (4), wherein the output end of the low-pressure reheat steam turbine (4) is connected to a steam turbine generator (3) via a detachable coupling (5); a high-pressure heater (11), wherein a pipeline is connected between the high-pressure heater (11) and the high-pressure back-pressure steam turbine (2); A heating network heater (12), wherein a heater drain pump (13) is fixed to the output end of the heating network heater (12).

2. A composite back pressure cogeneration device according to claim 1, characterized in that: A pipeline is connected between the low-pressure reheat steam turbine (4) and the boiler low-temperature reheater (6).

3. A composite back pressure cogeneration device according to claim 1, characterized in that: Pipelines are connected between the high-pressure heater (11), the boiler feed water pump (10), the deaerator (8), the deaerator water tank (9), and the high-temperature and ultra-high-pressure boiler (1).

4. The composite back pressure cogeneration device according to claim 1, characterized in that: A pipeline is connected between the heating network heater (12) and the low-pressure reheat steam turbine (4).

5. The composite back pressure cogeneration device according to claim 1, characterized in that: A low-pressure heater (14), wherein pipelines are connected between the low-pressure heater (14), the heater drain pump (13), the heating network heater (12), and the low-pressure reheat steam turbine (4).

6. A composite back pressure cogeneration device according to claim 5, characterized in that: A plurality of the high-pressure heaters (11) are arranged in series, and a plurality of the low-pressure heaters (14) are arranged in series.

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