A cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device

Abstract

The present application discloses a cogeneration system based on a liquid-vapor ejector and a water turbine power generation device, which includes a boiler, an intermediate pressure cylinder of a steam turbine, a low-pressure cylinder of the steam turbine, a condenser and a feed water pump connected in sequence through pipelines, and a liquid-vapor ejector, a water turbine power generation device and a heat network heater connected in sequence through pipelines. The steam outlet of the intermediate pressure cylinder of the steam turbine or the extraction port of the low-pressure cylinder of the steam turbine is connected to the liquid-vapor ejector through a pipeline; the intermediate tap of the feed water pump is connected to the liquid-vapor ejector through a pipeline, the liquid-vapor ejector is connected to the fluid inlet of the water turbine power generation device through a pipeline, and the water turbine power generation device is connected to the water inlet of the heat network heater through a pipeline. The high-pressure water coming out of the intermediate tap of the feed water pump entrains the steam outlet of the intermediate pressure cylinder of the steam turbine or the pressurized high-temperature steam coming out of the extraction port of the low-pressure cylinder of the steam turbine to form high-temperature and high-pressure water to drive the water turbine power generation device to generate electricity, and then the high-temperature and high-pressure water becomes high-temperature and low-pressure water for heating, reducing the steam heat exchange loss.

Description

Technical Field

[0001] The present invention belongs to the field of cogeneration of heat and power, and particularly relates to a cogeneration system based on a liquid-vapor ejector and a water turbine power generation device. Background Art

[0002] At present, the overall energy efficiency in China still needs to be improved. Cogeneration of heat and power is a process of simultaneously producing electric energy and heat energy, which has the advantages of high energy utilization rate and low comprehensive pollutant emissions, and is an important energy-saving technology.

[0003] In existing cogeneration of heat and power, steam with a certain temperature and pressure is usually used to drive the blades in the cylinder to rotate, and then drive the generator to generate electricity. The steam extracted from the extraction port of the intermediate pressure cylinder is usually connected to the heat network heater to provide heat energy for users.

[0004] However, there are problems such as insufficient utilization of residual pressure and residual heat in existing cogeneration units, and further energy-saving optimization is needed. For example, the steam pressure extracted from the extraction port of the intermediate pressure cylinder of a conventional cogeneration unit is often much higher than the saturated steam pressure required by the heat network heater, and there is a large loss during the heat exchange process between the steam and the heat network water, resulting in low overall energy efficiency of the unit.

[0005] In view of the deficiencies in the prior art, it is necessary to design a new cogeneration system.

[0006] Application Content

[0007] Therefore, the technical problem to be solved by this application is to overcome the defect that the steam pressure extracted from the extraction port of the intermediate pressure cylinder of a cogeneration unit in the prior art is often much higher than the saturated steam pressure required by the heat network heater, and there is a large loss during the heat exchange process between the steam and the heat network water, so as to provide a cogeneration system based on a liquid-vapor ejector and a water turbine power generation device.

[0008] To solve the above technical problems, the technical solution of this application is as follows:

[0009] A cogeneration system based on a liquid-vapor ejector and a water turbine power generation device, comprising a boiler, an intermediate pressure cylinder of a steam turbine, a low pressure cylinder of a steam turbine, a condenser and a feed water pump connected in sequence through pipelines, and further comprising a liquid-vapor ejector, a water turbine power generation device and a heat network heater connected in sequence through pipelines. The steam outlet of the intermediate pressure cylinder of the steam turbine or the extraction port of the low pressure cylinder of the steam turbine is connected to the injection fluid inlet of the liquid-vapor ejector through a pipeline; the intermediate tap of the feed water pump is connected to the motive fluid inlet of the liquid-vapor ejector through a pipeline, the fluid outlet of the liquid-vapor ejector is connected to the fluid inlet of the water turbine power generation device through a pipeline, and the water outlet of the water turbine power generation device is connected to the water inlet of the heat network heater through a pipeline.

[0010] Further, a first valve is provided on the pipeline between the intermediate tap of the feed water pump and the liquid-vapor ejector, and the first valve controls the water supply amount entering the liquid-vapor ejector from the intermediate tap of the feed water pump.

[0011] Further, a second valve is provided on the pipeline between the steam outlet of the intermediate pressure cylinder of the steam turbine and the liquid-vapor ejector, and the second valve controls the steam amount entering the liquid-vapor ejector from the steam outlet of the intermediate pressure cylinder of the steam turbine.

[0012] Further, a second valve is provided on the pipeline between the extraction port of the low pressure cylinder of the steam turbine and the liquid-vapor ejector, and the second valve controls the steam amount entering the liquid-vapor ejector from the extraction port of the low pressure cylinder of the steam turbine.

[0013] Further, it further includes a high pressure cylinder of the steam turbine connected between the boiler and the intermediate pressure cylinder of the steam turbine through a pipeline, and a condensate pump and a deaerator connected in sequence through a pipeline to the water outlet of the condenser, and the water outlet of the deaerator communicates with the water inlet of the feed water pump through a pipeline.

[0014] Further, a low pressure heater group is provided on the pipeline between the deaerator and the condensate pump, and the low pressure heater group is adapted to heat the condensate water entering the deaerator.

[0015] Further, a high pressure heater group is provided on the pipeline between the feed water pump and the boiler, and the high pressure heater group is adapted to heat the feed water entering the boiler.

[0016] Further, the drain pipeline of the heat network heater communicates with the outlet pipeline of the condenser.

[0017] Further, the water turbine in the water turbine power generation device is a reaction turbine.

[0018] Further, it further includes a heat network water pipe, the heat absorption end of the heat network water pipe is located inside the heat network heater, and the heat release end of the heat network water pipe is located outside the heat network heater.

[0019] The technical solution of this application has the following advantages:

[0020] 1. The cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device provided by this application. The pressurized high-temperature steam generated by the boiler exits from the steam outlet of the intermediate pressure cylinder of the steam turbine or from the extraction port of the low-pressure cylinder of the steam turbine, and then enters the liquid-vapor ejector along the pipeline from the ejector fluid inlet of the liquid-vapor ejector. The steam exiting from the steam outlet of the low-pressure cylinder of the steam turbine is condensed into condensate by the condenser. The condensate is pressurized by the feed water pump to form high-pressure water. Part of the high-pressure water enters the liquid-vapor ejector from the intermediate tap of the feed water pump along the pipeline from the motive fluid inlet of the liquid-vapor ejector. The high-pressure water, as the motive working medium, ejects the pressurized high-temperature steam to form high-temperature and high-pressure water, which flows out from the fluid outlet of the liquid-vapor ejector. Then, the high-temperature and high-pressure water enters the hydroelectric power generation device and drives it to generate electricity. After that, the pressure of the high-temperature and high-pressure water is consumed and becomes high-temperature and low-pressure water. The high-temperature and low-pressure water enters the heat network heater along the pipeline. The heat network water absorbs the heat of the high-temperature and low-pressure water in the heat network heater and becomes hot water to be provided to users. In this process, due to the residual pressure of the steam being used by the hydroelectric power generation device to generate electricity with the help of the high-temperature and high-pressure water coming out of the liquid-vapor ejector, the loss in the heat exchange process between the steam and the heat network water is reduced, and the overall energy efficiency of the unit is improved.

[0021] 2. In the cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device provided by this application, a first valve is provided on the pipeline between the intermediate tap of the feed water pump and the liquid-vapor ejector, and a second valve is provided on the pipeline between the steam outlet of the intermediate pressure cylinder of the steam turbine and the liquid-vapor ejector. By adjusting the opening degrees of the first valve and the second valve, the flow rate and pressure parameters of the fluid flowing out from the fluid outlet of the liquid-vapor ejector can be adjusted, thereby adjusting the power generation amount and heat supply amount of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic diagram of the cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device of this application.

[0024] DESCRIPTION OF THE REFERENCE NUMERALS

[0025] 1. Boiler; 2. High-pressure cylinder of the steam turbine; 3. Intermediate pressure cylinder of the steam turbine; 4. First valve; 5. Second valve; 6. Low-pressure cylinder of the steam turbine; 7. Condenser; 8. Condensate pump; 9. Low-pressure heater group; 10. Deaerator; 11. Feed water pump; 12. High-pressure heater group; 13. Liquid-vapor ejector; 14. Hydroelectric power generation device; 15. Heat network heater. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solution of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope of protection of the present application.

[0027] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0028] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0029] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0030] Embodiment

[0031] As Figure 1 shown, this embodiment provides a cogeneration system based on a liquid-vapor ejector and a water turbine power generation device, including a boiler 1, a high-pressure cylinder 2 of a steam turbine, a medium-pressure cylinder 3 of a steam turbine, a low-pressure cylinder 6 of a steam turbine, a condenser 7, a condensate pump 8, a low-pressure heater group 9, a deaerator 10, a feed pump 11, and a high-pressure heater group 12 that are connected in sequence through pipelines.

[0032] The steam generated in the boiler 1 enters the high-pressure cylinder 2 of the steam turbine, driving the blades in the high-pressure cylinder 2 of the steam turbine to rotate, and then driving the generator connected to the high-pressure cylinder 2 of the steam turbine to generate electricity. Part of the steam coming out of the steam outlet of the high-pressure cylinder 2 of the steam turbine is reheated by the boiler 1 again and then enters the intermediate-pressure cylinder 3 of the steam turbine to drive the blades in the intermediate-pressure cylinder 3 of the steam turbine to rotate, and then driving the generator connected to the intermediate-pressure cylinder 3 of the steam turbine to generate electricity. Part of the steam in the high-pressure cylinder 2 of the steam turbine can also be connected to the high-pressure heater group 12 to heat the feed water entering the high-pressure heater group 12. Part of the steam coming out of the steam outlet of the intermediate-pressure cylinder 3 of the steam turbine enters the low-pressure cylinder 6 of the steam turbine to drive the blades in the low-pressure cylinder 6 of the steam turbine to rotate, and then driving the generator connected to the low-pressure cylinder 6 of the steam turbine to generate electricity. Another part of the steam flows out of the steam outlet of the intermediate-pressure cylinder 3 of the steam turbine as needed for other uses. In this way, the steam volume in the low-pressure cylinder 6 of the steam turbine can be adjusted, and thus the frequency of the low-pressure cylinder 6 of the steam turbine can be adjusted. Of course, part of the steam extracted from the extraction port of the low-pressure cylinder 6 of the steam turbine can be used to heat the condensate flowing out of the condensate pump 8 in the low-pressure heater group 9, and can also be used for other purposes. By changing the amount of steam extracted from the extraction port of the low-pressure cylinder 6 of the steam turbine, the frequency of the low-pressure cylinder 6 of the steam turbine can be adjusted.

[0033] The steam coming out of the steam outlet of the low-pressure cylinder 6 of the steam turbine enters the condenser 7 and is condensed into condensate. The condensate enters the condensate pump 8 along the pipeline from the water outlet of the condensate pump 8 and is pressurized by the condensate pump 8 and then enters the low-pressure heater group 9. The condensate is heated by the steam extracted from the extraction port of the low-pressure cylinder 6 of the steam turbine in the low-pressure heater group 9 and then enters the deaerator 10. The deaerator 10 removes the oxygen in the condensate. Then the condensate enters the feed water pump 11 from the water outlet of the deaerator 10. For the convenience of explanation, the water entering the feed water pump 11 is called feed water. The feed water is pressurized by the feed water pump 11 to form high-pressure water. Part of the high-pressure water enters the high-pressure heater group 12. This part of the high-pressure water is heated by the steam extracted from the extraction port of the high-pressure cylinder 2 of the steam turbine in the high-pressure heater group 12 and then enters the boiler 1. Part of the high-pressure water flows out from the intermediate tap of the feed water pump 11.

[0034] The cogeneration system based on a liquid-vapor ejector and a water turbine power generation device further includes a liquid-vapor ejector 13, a water turbine power generation device 14, a heat network heater 15, and a heat network water pipe that are connected in sequence through pipelines. In this embodiment, the water turbine in the water turbine power generation device 14 is a reaction water turbine to improve the utilization efficiency of water energy. In addition, in this embodiment, the ejector fluid inlet of the liquid-vapor ejector 13 is connected to the steam outlet of the intermediate pressure cylinder 3 of the steam turbine or the extraction port of the low pressure cylinder 6 of the steam turbine through a pipeline, the motive fluid inlet of the liquid-vapor ejector 13 is connected to the intermediate tap of the feed water pump 11 through a pipeline, the fluid outlet of the liquid-vapor ejector 13 is connected to the fluid inlet of the water turbine power generation device 14 through a pipeline, the water outlet of the water turbine power generation device 14 is connected to the water inlet of the heat network heater 15 through a pipeline, the heat absorption end of the heat network water pipe is located inside the heat network heater 15, and the heat release end of the heat network water pipe is located outside the heat network heater 15. In this way, the pressurized high-temperature steam coming out of the steam outlet of the intermediate pressure cylinder 3 of the steam turbine or the extraction port of the low pressure cylinder 6 of the steam turbine can enter the liquid-vapor ejector 13 from the ejector fluid inlet of the liquid-vapor ejector 13, and the high-pressure water coming out of the intermediate tap of the feed water pump 11 can enter the liquid-vapor ejector 13 from the motive fluid inlet of the liquid-vapor ejector 13. The high-pressure water acts as a motive working medium to eject the pressurized high-temperature steam to form high-temperature and high-pressure water and flow out from the fluid outlet of the liquid-vapor ejector 13, and then enter the fluid inlet of the water turbine power generation device 14 along the pipeline. The high-temperature and high-pressure water uses its high-pressure characteristic to drive the water turbine power generation device 14 to generate electricity, and the pressure of the high-temperature and high-pressure water is consumed to become high-temperature and low-pressure water. The high-temperature and low-pressure water enters the heat network heater 15 from the water inlet of the heat network heater 15, and exchanges heat with the heat network water in the heat absorption end of the heat network water pipe in the heat network heater 15 to become condensate. The condensate pipeline of the heat network heater 15 is connected to the outlet pipeline of the condenser 7, so that the condensate of the heat network heater 15 can be recycled. The heat network water after heat absorption flows out from the heat release end of the heat network water pipe to supply heat to users.

[0035] In addition, a first valve 4 is provided on the pipeline between the intermediate tap of the feed water pump 11 and the liquid-vapor ejector 13. The first valve 4 is used to control the water supply amount from the intermediate tap of the feed water pump 11 into the liquid-vapor ejector 13. A second valve 5 is provided on the pipeline between the steam outlet of the intermediate pressure cylinder 3 of the steam turbine and the liquid-vapor ejector 13. The second valve 5 is used to control the steam amount from the steam outlet of the intermediate pressure cylinder 3 of the steam turbine into the liquid-vapor ejector 13. Of course, the pressurized high-temperature steam can also come from the extraction port of the low-pressure cylinder 6 of the steam turbine. In this case, a third valve (not shown) is correspondingly provided between the extraction port of the low-pressure cylinder 6 of the steam turbine and the entrained fluid inlet of the liquid-vapor ejector 13. The third valve is used to control the steam amount from the extraction port of the low-pressure cylinder 6 of the steam turbine into the liquid-vapor ejector 13. In this way, by controlling the opening degrees of the first valve 4 and the second valve 5 or by controlling the opening degrees of the first valve 4 and the third valve, the flow rate and pressure parameters of the fluid flowing out from the fluid outlet of the liquid-vapor ejector 13 can be adjusted, thereby adjusting the power generation amount and heat supply amount of the entire system.

[0036] In this embodiment, the pressurized high-temperature steam generated by the boiler 1 flows out from the steam outlet of the intermediate pressure cylinder 3 of the steam turbine or from the extraction port of the low-pressure cylinder 6 of the steam turbine, and then enters the liquid-vapor ejector 13 along the pipeline from the entrained fluid inlet of the liquid-vapor ejector 13. The steam flowing out from the steam outlet of the low-pressure cylinder 6 of the steam turbine is condensed into condensate by the condenser 7. The condensate is pressurized by the feed water pump 11 to form high-pressure water. Part of the high-pressure water enters the liquid-vapor ejector 13 from the intermediate tap of the feed water pump 11 along the pipeline from the motive fluid inlet of the liquid-vapor ejector 13. The high-pressure water serves as the motive working medium to entrain the pressurized high-temperature steam to form high-temperature and high-pressure water and flow out from the fluid outlet of the liquid-vapor ejector 13. Then, the high-temperature and high-pressure water enters the water turbine power generation device 14 and drives it to generate electricity. After that, the pressure of the high-temperature and high-pressure water is consumed and becomes high-temperature and low-pressure water. The high-temperature and low-pressure water enters the heat network heater 15 along the pipeline. The heat network water absorbs the heat of the high-temperature and low-pressure water in the heat network heater 15 and becomes hot water to be provided to users. In this process, since the residual pressure of the steam is used by the water turbine power generation device 14 to generate electricity by means of the high-temperature and high-pressure water flowing out from the liquid-vapor ejector 13, the loss during the heat exchange process between the steam and the heat network water is reduced, and the overall energy efficiency of the unit is improved.

[0037] Briefly speaking, for the cogeneration system based on the liquid-vapor ejector and the water turbine power generation device provided in this embodiment, the vapor-liquid two-phase fluid is mixed in the liquid-vapor ejector 13 to generate high-temperature and high-pressure water, fully utilizing the latent heat and residual pressure of the steam supplied by the intermediate pressure cylinder 3 or the low-pressure cylinder 6 of the steam turbine, playing a role in energy conservation and emission reduction. Moreover, the pressure energy of the high-temperature and high-pressure water is fully utilized to generate electricity through the hydraulic power generation technology. After the high-temperature and high-pressure water becomes high-temperature and low-pressure water, it is used for heat supply, realizing the cascaded utilization of energy and reducing the energy consumption of the unit.

[0038] Obviously, the above embodiments are only examples for clear illustration, and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device, characterized in that, It includes a boiler (1), an intermediate-pressure cylinder (3) of a steam turbine, a low-pressure cylinder (6) of the steam turbine, a condenser (7) and a feed water pump (11) connected in sequence through pipelines. It also includes a liquid-vapor ejector (13), a water turbine power generation device (14) and a heat network heater (15) connected in sequence through pipelines. The steam outlet of the intermediate-pressure cylinder (3) of the steam turbine or the extraction port of the low-pressure cylinder (6) of the steam turbine is connected to the injection fluid inlet of the liquid-vapor ejector (13) through a pipeline; the intermediate tap of the feed water pump (11) is connected to the motive fluid inlet of the liquid-vapor ejector (13) through a pipeline. The fluid outlet of the liquid-vapor ejector (13) is connected to the fluid inlet of the water turbine power generation device (14) through a pipeline. The water outlet of the water turbine power generation device (14) is connected to the water inlet of the heat network heater through a pipeline; A first valve (4) is provided on the pipeline between the intermediate tap of the feed water pump (11) and the liquid-vapor ejector (13), and the first valve (4) controls the water supply amount entering the liquid-vapor ejector (13) from the intermediate tap of the feed water pump (11); It also includes a high-pressure cylinder (2) of the steam turbine connected through a pipeline between the boiler (1) and the intermediate-pressure cylinder (3) of the steam turbine, and a condensate pump (8) and a deaerator (10) connected in sequence through pipelines at the water outlet of the condenser (7). The water outlet of the deaerator (10) is connected to the water inlet of the feed water pump (11) through a pipeline; A low-pressure heater group (9) is provided on the pipeline between the deaerator (10) and the condensate pump (8), and the low-pressure heater group (9) is suitable for heating the condensate water entering the deaerator (10).

2. The cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device according to claim 1, wherein A second valve (5) is provided on the pipeline between the steam outlet of the intermediate-pressure cylinder (3) of the steam turbine and the liquid-vapor ejector (13), and the second valve (5) controls the steam amount entering the liquid-vapor ejector (13) from the steam outlet of the intermediate-pressure cylinder (3) of the steam turbine.

3. The cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device according to claim 1, wherein A third valve is provided on the pipeline between the extraction port of the low-pressure cylinder (6) of the steam turbine and the liquid-vapor ejector (13), and the third valve controls the steam amount entering the liquid-vapor ejector (13) from the extraction port of the low-pressure cylinder (6) of the steam turbine.

4. The cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device according to claim 1, characterized in that, A high-pressure heater group (12) is provided on the pipeline between the feed water pump (11) and the boiler (1), and the high-pressure heater group (12) is suitable for heating the feed water entering the boiler (1).

5. The cogeneration system based on a liquid-vapor ejector and a water turbine power generation device according to claim 1, wherein The drain pipeline of the heat network heater is connected to the outlet pipeline of the condenser (7).

6. The cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device according to claim 1, wherein The water turbine in the water turbine power generation device (14) is a reaction water turbine.

7. The cogeneration system based on a liquid-vapor ejector and a hydroelectric power generation device according to claim 1, characterized in that, It also includes a heat network water pipe. The heat absorption end of the heat network water pipe is located inside the heat network heater (15), and the heat release end of the heat network water pipe is located outside the heat network heater (15).

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