Coal-fired combined heat and power generation system integrating double-circulation heat pump heat storage

Abstract

The utility model relates to a coal-fired cogeneration system integrating double-circulation heat pump heat storage. The coal-fired cogeneration system comprises a steam turbine system, a heat supply network water heating system, a heat pump system and a storage tank heat storage and release system. The steam turbine system comprises a boiler (23), a superheater outlet of the boiler (23) is connected with an inlet of a third mixing valve (22), another inlet of the third mixing valve (22) is connected with a cold source outlet of an auxiliary superheater (17), and an outlet of the third mixing valve (22) is connected with an inlet of a high-pressure cylinder (28). On the basis of a traditional combined heat and power generation system, excessive electric energy is converted into heat energy to be stored and utilized by integrating a heat pump and a heat storage system. According to the system, the overall heating performance coefficient is improved through low-temperature heat pump circulation, the heat supply capacity is enhanced, and thermoelectricity decoupling and low-carbon flexible operation of a coal-fired cogeneration unit can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to coal-fired power generation technical field, concretely relates to a kind of coal-fired cogeneration system of integrated double-cycle heat pump heat storage. BACKGROUND

[0002] Energy storage technology is one of the key technologies to solve the instability and intermittency of renewable energy, adjust the peak and valley of power grid, and improve the safety of power system. The heat pump energy storage technology based on thermodynamic cycle has the advantages of breaking the geographical condition limit, no combustion, large energy storage capacity, high energy storage density, safety and high efficiency, etc. In the energy storage stage, the system uses a certain type of heat pump, extracts heat energy from the low-temperature heat storage system through electric drive, and delivers it to the high-temperature heat storage system. In the energy release stage, the system works as a heat engine, uses the stored heat energy to do work and thus generates electricity. Therefore, it is considered to be a high-efficiency, low-cost and large-scale energy storage technology comparable to fossil energy in the future.

[0003] According to the existing relevant literature, when the energy storage system of heat pump energy storage technology is a typical inverse Brayton cycle, the COP and round-trip efficiency are low, and the excess power cannot be fully utilized. When the energy release system is a typical Rankine cycle cogeneration unit, the inverse Brayton system has no peak shaving capability and cannot improve the flexibility of the system.

[0004] In view of the shortcomings of the existing method, the utility model provides a coal-fired cogeneration system integrated with double-cycle heat pump heat storage, which changes the traditional inverse Brayton cycle into a double-cycle heat pump system composed of high-temperature heat pump cycle and low-temperature heat pump cycle. The high-temperature heat pump cycle is used to heat molten salt, and the low-temperature heat pump cycle is used to heat hot water. The low-temperature heat pump cycle can improve the COP of the entire heat pump system, and can also improve the decoupling capability of the cogeneration unit for heating. UTILITY MODEL CONTENT

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A coal-fired cogeneration system integrated with double-cycle heat pump heat storage, characterized by comprising a steam turbine system, a hot water heating system, a heat pump system and a storage tank heat storage and release system.

[0007] The steam turbine system comprises a boiler (23), an outlet of a superheater of the boiler (23) is connected with an inlet of a third mixing valve (22), another inlet of the third mixing valve (22) is connected with a cold source outlet of an auxiliary superheater (17), an outlet of the third mixing valve (22) is connected with an inlet of a high-pressure cylinder (28), an outlet of the high-pressure cylinder (28) is connected with an inlet of a fourth split valve (25), an outlet of the fourth split valve (25) is connected with an inlet of a reheater of the boiler (23) and a cold source inlet of an auxiliary reheater (21) respectively, an inlet of a fourth mixing valve (26) is connected with an outlet of the reheater of the boiler (23) and a cold source outlet of the auxiliary reheater (21) respectively, an outlet of the fourth mixing valve (26) is connected with an inlet of a medium-pressure cylinder (30), an outlet of the medium-pressure cylinder (30) is connected with an inlet of a low-pressure cylinder (34) and an inlet of a fifth split valve (31) respectively, an outlet of the fifth split valve (31) is connected with a steam inlet of a deaerator (32), an outlet of the low-pressure cylinder (34) is connected with an inlet of a condenser (35), an outlet of the condenser (35) is connected with an inlet of a condensate pump (33), an outlet of the condensate pump (33) is connected with a feedwater inlet of the deaerator (32), an outlet of the deaerator (32) is connected with an inlet of a feedwater pump (27), an outlet of the feedwater pump (27) is connected with an inlet of a third split valve (24), an outlet of the third split valve (24) is connected with a feedwater inlet of the boiler (23); the high-pressure cylinder (28), the medium-pressure cylinder (30), the low-pressure cylinder (34) and a generator (36) are coaxially connected;

[0008] The heat network water heating system comprises the fifth split valve (31), another outlet of the fifth split valve (31) is connected with a heat source inlet of a peak heater (29), a heat source outlet of the peak heater (29) is connected with a hot well of the condenser (35), the heat network return water is connected with a cold source inlet of the heat exchanger (8), a cold source outlet of the heat exchanger (8) is connected with a cold source inlet of the peak heater (29), a cold source outlet of the peak heater (29) is connected with the heat network to supply heat;

[0009] The heat pump system comprises a first compressor (1), an inlet of the first compressor (1) is connected with a cold source outlet of a regenerator (2), an outlet of the first compressor (1) is connected with a heat source inlet of a heat source heat exchanger (9), a heat source outlet of the heat source heat exchanger (9) is connected with a heat source inlet of the regenerator (2), an inlet of a first mixing valve (4) is connected with the heat source outlet of the regenerator (2) and a heat source outlet of a heat exchanger (8) respectively, an outlet of the first mixing valve (4) is connected with an inlet of a turbine (6), an outlet of the turbine (6) is connected with a cold source inlet of a cold source heat exchanger (5), a cold source outlet of the cold source heat exchanger (5) is connected with an inlet of a first split valve (3), an outlet of the first split valve (3) is connected with the cold source inlet of the regenerator (2) and an inlet of a second compressor (7) respectively, an outlet of the second compressor (7) is connected with a heat source inlet of the heat exchanger (8);

[0010] The heat storage and release system comprises a cold tank (13), an inlet of the cold tank (13) is connected with an outlet of the second throttling valve (15), the inlet of the cold tank (13) is connected with an inlet of the first circulating pump (11), an outlet of the first circulating pump (11) is connected with a cold source inlet of the heat source heat exchanger (9), a cold source outlet of the heat source heat exchanger (9) is connected with an inlet of the first throttling valve (10), an outlet of the first throttling valve (10) is connected with an inlet of the hot tank (12), an outlet of the hot tank (12) is connected with an inlet of the second circulating pump (14), an outlet of the second circulating pump (14) is connected with an inlet of the second throttling valve (16), an outlet of the second throttling valve (16) is connected with inlets of the auxiliary superheater (17) and the auxiliary reheater (21), an inlet of the second mixing valve (18) is connected with a heat source outlet of the auxiliary superheater (17) and the auxiliary reheater (21) respectively, an outlet of the second mixing valve (18) is connected with a heat source inlet of the evaporator (19), a heat source outlet of the evaporator (19) is connected with a heat source inlet of the preheater (20), a heat source outlet of the preheater (20) is connected with an inlet of the second throttling valve (15); the other outlet of the third throttling valve (24) is connected with a cold source inlet of the preheater (20), a cold source outlet of the preheater (20) is connected with a cold source inlet of the evaporator (19), and a cold source outlet of the evaporator (19) is connected with a cold source inlet of the auxiliary superheater (17).

[0011] The coal-fired combined heat and power system integrated with the double-cycle heat pump heat storage is characterized in that, in the heat storage and release system, the electricity of the first compressor (1) and the second compressor (7) is provided by the turbine (6) and the abandoned electricity of the new energy station.

[0012] The coal-fired combined heat and power system integrated with the double-cycle heat pump heat storage is characterized in that, in the heat storage and release system, the heat source of the cold source heat exchanger (5) comprises methanol.

[0013] The coal-fired combined heat and power system integrated with the double-cycle heat pump heat storage is characterized in that, in the heat storage and release system, the heat storage working medium in the storage tank comprises binary molten salt, and in the heat pump system, the circulating working medium comprises argon and carbon dioxide.

[0014] The coal-fired combined heat and power system integrated with the double-cycle heat pump heat storage is characterized in that, in the heat storage and release system, the distribution ratio of the first throttling valve (3) is determined by the heat supply, the abandoned electricity and the boiler evaporation capacity.

[0015] The coal-fired combined heat and power system integrated with the double-cycle heat pump heat storage is characterized in that, in the heat pump system, the pressure ratio of the first compressor (1) and the second compressor (7) is the same.

[0016] The positive and beneficial results of the utility model are as follows:

[0017] The utility model discloses a kind of integrated double-cycle heat pump heat storage's coal-fired cogeneration system, the utility model increases compressor and heat exchanger in reverse brayton cycle, constitute high-temperature heat pump cycle and low-temperature heat pump cycle, high-temperature heat pump cycle is used to heat molten salt, low-temperature heat pump cycle is used to heat heat network water, the COP of entire heat pump system can be improved by low-temperature heat pump cycle, for heating also can promote the decoupling capability of cogeneration unit. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a kind of integrated double-cycle heat pump heat storage's coal-fired cogeneration system structure schematic view of the utility model.

[0019] In the drawing: 1-first compressor 2-heat regenerator 3-first shunt valve 4-first mixing valve 5-cold source heat exchanger 6-turbine 7-second compressor 8-heat exchanger 9-heat source heat exchanger 10-first throttling valve 11-first circulating pump 12-heat tank 13-cold tank 14-second circulating pump 15-second throttling valve 16-second shunt valve 17-auxiliary superheater 18-second mixing valve 19-evaporator 20-preheater 21-auxiliary superheater 22-third mixing valve 23-boiler 24-third shunt valve 25-fourth shunt valve 26-fourth mixing valve 27-feed pump 28-high pressure cylinder 29-peak heater 30-medium pressure cylinder 31-fifth shunt valve 32-oxygen remover 33-condensate pump 34-low pressure cylinder 35-condenser 36-generator. DETAILED DESCRIPTION

[0020] The utility model will be further described below in conjunction with the drawings and some specific embodiments in the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all embodiments, based on the embodiment in the utility model, all other embodiments obtained by ordinary skill in the art without doing creative work belong to the scope of the utility model protection.

[0021] The utility model provides a kind of integrated double-cycle heat pump heat storage's coal-fired cogeneration system as Figure 1 The system is composed of steam turbine system, heat network water heating system, heat pump system and storage tank heat storage system.

[0022] The turbine system includes a boiler (23), the superheater outlet of the boiler (23) is connected to the inlet of a third mixing valve (22), another inlet of the third mixing valve (22) is connected to the cold source outlet of an auxiliary superheater (17), the outlet of the third mixing valve (22) is connected to the inlet of a high-pressure cylinder (28), the outlet of the high-pressure cylinder (28) is connected to the inlet of a fourth diverter valve (25), the outlet of the fourth diverter valve (25) is connected to the inlet of the reheater of the boiler (23) and the cold source inlet of the auxiliary reheater (21), the inlet of the fourth mixing valve (26) is connected to the outlet of the reheater of the boiler (23) and the cold source outlet of the auxiliary reheater (21), the outlet of the fourth mixing valve (26) is connected to the inlet of an intermediate-pressure cylinder (30), and the intermediate-pressure cylinder (30) is connected to the inlet of the intermediate-pressure cylinder (30). The outlets of the cylinders are connected to the inlet of the low-pressure cylinder (34) and the inlet of the fifth diversion valve (31), respectively. The outlet of the fifth diversion valve (31) is connected to the steam inlet of the deaerator (32). The outlet of the low-pressure cylinder (34) is connected to the inlet of the condenser (35). The outlet of the condenser (35) is connected to the inlet of the condensate pump (33). The outlet of the condensate pump (33) is connected to the feedwater inlet of the deaerator (32). The outlet of the deaerator (32) is connected to the inlet of the feedwater pump (27). The outlet of the feedwater pump (27) is connected to the inlet of the third diversion valve (24). The outlet of the third diversion valve (24) is connected to the feedwater inlet of the boiler (23). The high-pressure cylinder (28), the medium-pressure cylinder (30), the low-pressure cylinder (34) and the generator (36) are coaxially connected.

[0023] The heating network water heating system includes a fifth diversion valve (31), the other outlet of which is connected to the heat source inlet of the peak heater (29), the heat source outlet of the peak heater (29) is connected to the hot well of the condenser (35), the heating network return water is connected to the cold source inlet of the heat exchanger (8), the cold source outlet of the heat exchanger (8) is connected to the cold source inlet of the peak heater (29), and the cold source outlet of the peak heater (29) is connected to the heating network for heating.

[0024] The heat pump system includes a first compressor (1), the inlet of the first compressor (1) is connected to the cold source outlet of the regenerator (2), the outlet of the first compressor (1) is connected to the heat source inlet of the heat source heat exchanger (9), the heat source outlet of the heat source heat exchanger (9) is connected to the heat source inlet of the regenerator (2), the inlet of the first mixing valve (4) is connected to the heat source outlet of the regenerator (2) and the heat source outlet of the heat exchanger (8) respectively, the outlet of the first mixing valve (4) is connected to the inlet of the turbine (6), the outlet of the turbine (6) is connected to the cold source inlet of the cold source heat exchanger (5), the cold source outlet of the cold source heat exchanger (5) is connected to the inlet of the first diversion valve (3), the outlet of the first diversion valve (3) is connected to the cold source inlet of the regenerator (2) and the inlet of the second compressor (7) respectively, and the outlet of the second compressor (7) is connected to the heat source inlet of the heat exchanger (8).

[0025] The heat storage and release system comprises a cold tank (13), an inlet of the cold tank (13) is connected with an outlet of a second throttling valve (15), the inlet of the cold tank (13) is connected with an inlet of a first circulating pump (11), an outlet of the first circulating pump (11) is connected with a cold source inlet of a heat source heat exchanger (9), a cold source outlet of the heat source heat exchanger (9) is connected with an inlet of a first throttling valve (10), an outlet of the first throttling valve (10) is connected with an inlet of a hot tank (12), an outlet of the hot tank (12) is connected with an inlet of a second circulating pump (14), an outlet of the second circulating pump (14) is connected with an inlet of a second distribution valve (16), an outlet of the second distribution valve (16) is connected with inlets of an auxiliary superheater (17) and an auxiliary reheater (21), an inlet of a second mixing valve (18) is connected with a heat source outlet of the auxiliary superheater (17) and the auxiliary reheater (21) respectively, an outlet of the second mixing valve (18) is connected with a heat source inlet of an evaporator (19), a heat source outlet of the evaporator (19) is connected with a heat source inlet of a preheater (20), a heat source outlet of the preheater (20) is connected with an inlet of the second throttling valve (15); another outlet of a third distribution valve (24) is connected with a cold source inlet of the preheater (20), a cold source outlet of the preheater (20) is connected with a cold source inlet of the evaporator (19), and a cold source outlet of the evaporator (19) is connected with a cold source inlet of the auxiliary superheater (17).

[0026] The coal-fired combined heat and power system integrated with a double-cycle heat pump heat storage system, characterized in that, in the heat storage and release system, the electricity of the first compressor (1) and the second compressor (7) is provided by the turbine (6) and the abandoned electricity of the new energy station.

[0027] The coal-fired combined heat and power system integrated with a double-cycle heat pump heat storage system, characterized in that, in the heat storage and release system, the heat source of the cold source heat exchanger (5) comprises methanol.

[0028] The coal-fired combined heat and power system integrated with a double-cycle heat pump heat storage system, characterized in that, in the heat storage and release system, the heat storage working medium in the storage tank comprises binary molten salt, and in the heat pump system, the circulating working medium comprises argon and carbon dioxide.

[0029] The coal-fired combined heat and power system integrated with a double-cycle heat pump heat storage system, characterized in that, in the heat storage and release system, the distribution ratio of the first distribution valve (3) is determined by the heat supply, the abandoned electricity and the boiler evaporation capacity.

[0030] The coal-fired combined heat and power system integrated with a double-cycle heat pump heat storage system, characterized in that, in the heat pump system, the pressure ratio of the first compressor (1) and the second compressor (7) is the same.

[0031] Finally, it is explained that the above examples are merely used to illustrate the technical solutions of the present application and are not limiting, and other modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art shall be covered in the scope of the claims of the present application as long as they do not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. A coal-fired cogeneration system integrating dual-cycle heat pump thermal storage, characterized in that, This includes steam turbine systems, heating network water heating systems, heat pump systems, and storage tank heat storage and release systems; The turbine system includes a boiler (23), the superheater outlet of the boiler (23) is connected to the inlet of a third mixing valve (22), another inlet of the third mixing valve (22) is connected to the cold source outlet of an auxiliary superheater (17), the outlet of the third mixing valve (22) is connected to the inlet of a high-pressure cylinder (28), the outlet of the high-pressure cylinder (28) is connected to the inlet of a fourth diverter valve (25), the outlet of the fourth diverter valve (25) is connected to the inlet of the reheater of the boiler (23) and the cold source inlet of the auxiliary reheater (21), the inlet of the fourth mixing valve (26) is connected to the outlet of the reheater of the boiler (23) and the cold source outlet of the auxiliary reheater (21), the outlet of the fourth mixing valve (26) is connected to the inlet of an intermediate-pressure cylinder (30), and the intermediate-pressure cylinder (30) is connected to the inlet of the intermediate-pressure cylinder (30). The outlets of the cylinders are connected to the inlet of the low-pressure cylinder (34) and the inlet of the fifth diversion valve (31), respectively. The outlet of the fifth diversion valve (31) is connected to the steam inlet of the deaerator (32). The outlet of the low-pressure cylinder (34) is connected to the inlet of the condenser (35). The outlet of the condenser (35) is connected to the inlet of the condensate pump (33). The outlet of the condensate pump (33) is connected to the feedwater inlet of the deaerator (32). The outlet of the deaerator (32) is connected to the inlet of the feedwater pump (27). The outlet of the feedwater pump (27) is connected to the inlet of the third diversion valve (24). The outlet of the third diversion valve (24) is connected to the feedwater inlet of the boiler (23). The high-pressure cylinder (28), the medium-pressure cylinder (30), the low-pressure cylinder (34) and the generator (36) are coaxially connected. The heating network water heating system includes a fifth diversion valve (31), the other outlet of which is connected to the heat source inlet of the peak heater (29), the heat source outlet of the peak heater (29) is connected to the hot well of the condenser (35), the heating network return water is connected to the cold source inlet of the heat exchanger (8), the cold source outlet of the heat exchanger (8) is connected to the cold source inlet of the peak heater (29), and the cold source outlet of the peak heater (29) is connected to the heating network for heating. The heat pump system includes a first compressor (1), the inlet of the first compressor (1) is connected to the cold source outlet of the regenerator (2), the outlet of the first compressor (1) is connected to the heat source inlet of the heat source heat exchanger (9), the heat source outlet of the heat source heat exchanger (9) is connected to the heat source inlet of the regenerator (2), the inlet of the first mixing valve (4) is connected to the heat source outlet of the regenerator (2) and the heat source outlet of the heat exchanger (8) respectively, the outlet of the first mixing valve (4) is connected to the inlet of the turbine (6), the outlet of the turbine (6) is connected to the cold source inlet of the cold source heat exchanger (5), the cold source outlet of the cold source heat exchanger (5) is connected to the inlet of the first diversion valve (3), the outlet of the first diversion valve (3) is connected to the cold source inlet of the regenerator (2) and the inlet of the second compressor (7) respectively, and the outlet of the second compressor (7) is connected to the heat source inlet of the heat exchanger (8). The storage tank heat storage and release system includes a cold tank (13). The inlet of the cold tank (13) is connected to the outlet of the second throttle valve (15). The inlet of the cold tank (13) is connected to the inlet of the first circulating pump (11). The outlet of the first circulating pump (11) is connected to the cold source inlet of the heat source heat exchanger (9). The cold source outlet of the heat source heat exchanger (9) is connected to the inlet of the first throttle valve (10). The outlet of the first throttle valve (10) is connected to the inlet of the hot tank (12). The outlet of the hot tank (12) is connected to the inlet of the second circulating pump (14). The outlet of the second circulating pump (14) is connected to the inlet of the second diverter valve (16). The outlet of the second diverter valve (16) is connected to the auxiliary superheater (17). The inlet of the second mixing valve (18) is connected to the heat source outlet of the auxiliary superheater (17) and the auxiliary reheater (21), respectively. The outlet of the second mixing valve (18) is connected to the heat source inlet of the evaporator (19). The heat source outlet of the evaporator (19) is connected to the heat source inlet of the preheater (20). The heat source outlet of the preheater (20) is connected to the inlet of the second throttle valve (15). The other outlet of the third diverter valve (24) is connected to the cold source inlet of the preheater (20). The cold source outlet of the preheater (20) is connected to the cold source inlet of the evaporator (19). The cold source outlet of the evaporator (19) is connected to the cold source inlet of the auxiliary superheater (17).

2. The coal-fired cogeneration system with integrated dual-cycle heat pump thermal storage according to claim 1, characterized in that, In the aforementioned storage tank heat storage and release system, the power of the first compressor (1) and the second compressor (7) is provided by the turbine (6) and the abandoned power from the new energy power station.

3. The coal-fired cogeneration system with integrated dual-cycle heat pump thermal storage according to claim 1, characterized in that, In the aforementioned storage tank heat storage and release system, the heat source of the cold source heat exchanger (5) includes methanol.

4. A coal-fired cogeneration system with integrated dual-cycle heat pump thermal storage according to claim 1, characterized in that, In the aforementioned storage tank heat storage and release system, the heat storage medium in the storage tank includes a binary molten salt, and in the aforementioned heat pump system, the circulating medium includes argon and carbon dioxide.

5. A coal-fired cogeneration system with integrated dual-cycle heat pump thermal storage according to claim 1, characterized in that, In the aforementioned storage tank heat storage and release system, the flow ratio of the first diversion valve (3) is determined by the heat supply, the abandoned power and the boiler evaporation rate.

6. A coal-fired cogeneration system with integrated dual-cycle heat pump thermal storage according to claim 1, characterized in that, In the heat pump system, the first compressor (1) and the second compressor (7) have the same pressure ratio.

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