Combined heat and power generation system of integrated heat pump

Abstract

The utility model discloses a combined heat and power generation system of an integrated heat pump. The combined heat and power generation system comprises a steam turbine system and a heat supply network water heating system. The steam turbine system comprises an intermediate-pressure cylinder, a low-pressure cylinder and a condenser; the heat supply network water heating system comprises a condenser (electric heat pump), an absorber, a condenser (absorption heat pump) and a peak heater. Heat supply network return water is connected with an evaporator heat source inlet of the absorption heat pump, an evaporator heat source outlet is connected with a condenser heat supply network water inlet of the electric heat pump, a heat supply network water outlet of the electric heat pump is connected with an absorber heat supply network water inlet of the absorption heat pump, and a heat supply network water outlet of the absorber is connected with a condenser heat supply network water inlet of the absorption heat pump. A heat supply network water outlet of the condenser is connected with a heat supply network water inlet of the peak heater, and a heat supply network water outlet of the peak heater is connected with a heat supply network to supply water for the heat supply network. By recycling more waste heat, the heat supply capacity and the total efficiency of the system are improved while the combined heat and power generation system obtains more flexible power generation load adjusting capacity.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal-fired power generation, and in particular relates to a heat and power cogeneration system with an integrated heat pump. Background Art

[0002] With the growth of energy demand and the low-carbon transformation, my country's energy production structure is undergoing a huge transformation. The proportion of renewable energy such as wind power and solar power in the power generation side is constantly increasing, and the proportion of traditional coal-fired units is gradually decreasing. This has a significant impact on the security of the power system. On the one hand, renewable energy such as wind power and solar power has strong randomness and volatility, which poses new challenges to the regulation capacity of the power grid. On the other hand, in order to enable large-scale grid connection of renewable energy, coal-fired units, which are currently the main energy supply, need better peak-shaving capabilities.

[0003] Due to its high energy efficiency, CHP has been widely used in China as a low-carbon technology. CHP also plays an important role in energy security and the resilience of the power system. However, due to the heat-electric coupling characteristics, the CHP system has a limited range of power load regulation during the heating season, which hinders the development of regional renewable energy. In addition, to ensure safe operation, the steam turbine inevitably uses some cooling steam. However, cooling steam is often difficult to use due to its low temperature.

[0004] The existing integrated heat pump solution is a solution to improve the peak load performance of the cogeneration unit. Its main principle is to use the heat pump to recover the waste heat of air, exhaust steam or flue gas of the unit, thereby reducing the extraction heat supply, and thus improving the load regulation capacity of the cogeneration unit to a certain extent. However, the solution of simply integrating electric heat pumps or absorption heat pumps has limited improvement on the regulation capacity of the unit. How to further improve the load flexibility of coal-fired cogeneration units during the heating period and reduce exhaust steam losses is still an important direction for its technical development. Summary of the invention

[0005] In view of the shortcomings of the existing methods, the utility model provides a heat and power cogeneration system with an integrated heat pump. Integrating a heat pump in the heat and power cogeneration system improves the efficiency of the heat and power cogeneration unit, and enhances the power generation load regulation capability and exhaust steam recovery capability.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A heat and power cogeneration system with integrated heat pump, characterized in that it includes a steam turbine system and a heat network water heating system;

[0008] The steam turbine system comprises an intermediate pressure cylinder (1), steam from the high pressure cylinder is connected to the inlet of the intermediate pressure cylinder (1), the outlet of the intermediate pressure cylinder (1) is connected to the inlet of a first diverter valve (20), the outlet of the first diverter valve (20) is connected to the inlets of a first pressure control valve (2) and a second pressure control valve (3), respectively, the outlet of the first pressure control valve (2) is connected to the inlet of a low pressure cylinder (4), the steam outlet of the low pressure cylinder (4) is connected to the steam inlet of a condenser (5), the condensate inlet of the condenser (5) is connected to the circulating cooling water outlet of a condensation tower (7), and the condensate outlet of the condenser (5) is connected to the inlet of a second diverter valve (8); the intermediate pressure cylinder (1), the low pressure cylinder (4) and the generator (6) are coaxially connected;

[0009] The hot water heating system comprises a first condenser (9) of an electric heat pump, an absorber (10) of an absorption heat pump, a second condenser (11) and a peak heater (12); the outlet of the second diverter valve (8) is respectively connected to the inlet of circulating cooling water of a condensation tower (7) and the inlet of a heat source of a first evaporator (14), and the heat source outlet of the first evaporator (14) is connected to the inlet of circulating cooling water of the condensation tower (7); the refrigerant outlet of the evaporator (14) is connected to the inlet of a compressor (15), and the outlet of the compressor (15) is connected to the inlet of the first condenser (9). The outlet of the first condenser (9) is connected to the inlet of the first throttle valve (16), and the outlet of the first throttle valve (16) is connected to the refrigerant inlet of the first evaporator (14); the refrigerant outlet of the second evaporator (13) is connected to the inlet of the absorber (10), the weak solution outlet of the absorber (10) is connected to the solution pump (17), the heat exchanger (21) and the generator (18) in sequence, the concentrated solution outlet of the generator (18) is connected to the heat exchanger (21) and the second throttle valve (19) in sequence, and the outlet of the second throttle valve (19) is connected to the absorber (10). The concentrated solution inlet of the receiver (10) is connected; the refrigerant outlet of the generator (18) is connected to the second condenser (11), the third throttle valve (23), and the second evaporator (13) in sequence; the outlet of the second pressure control valve (3) is connected to the inlet of the third diverter valve (22), and the outlet of the third diverter valve (22) is connected to the generator (18) and the peak heater (12) respectively; the return water outlet of the hot network is firstly connected to the heat source inlet of the second evaporator (13), and the heat source outlet of the second evaporator (13) is connected to the hot network water inlet of the first condenser (9) The hot water network outlet of the first condenser (9) is connected to the inlet of the fourth diverter valve (24), the outlet of the fourth diverter valve (24) is respectively connected to the inlet of the mixing valve (25) and the hot water network inlet of the absorber (10), the hot water network outlet of the absorber (10) is connected to the hot water network inlet of the second condenser (11), the hot water network outlet of the second condenser (11) is connected to the inlet of the mixing valve (25), the outlet of the mixing valve (25) is connected to the hot water network inlet of the peak heater (12), and the hot water network outlet of the peak heater (12) is connected to the hot network.

[0010] The return water from the heating network enters the low-temperature heat source inlet of the second evaporator (13) to heat the circulating medium, and then enters the water inlet of the first condenser (9) from the low-temperature heat source outlet of the second evaporator (13) to complete the first heating, and then enters the water inlet of the heating network of the absorber (10) from the water outlet of the first condenser (9) to complete the second heating, and then enters the water inlet of the heating network of the second condenser (11) from the water outlet of the heating network of the absorber (10) to complete the third heating, and finally enters the peak heater (12) from the water outlet of the heating network of the second condenser (11) to complete the fourth heating, and is used as the water supply for the heating network after reaching the required temperature.

[0011] The positive and beneficial effects of the utility model:

[0012] The utility model discloses a heat and power cogeneration system with integrated heat pump. By integrating a heat pump system in a traditional heat and power cogeneration system, the exhaust steam recovery capacity is improved, and better operation flexibility is achieved than that of a traditional integrated electric heat pump or absorption heat pump system. In the utility model, the return water from the heat network first enters the evaporator (absorption heat pump) to heat the circulating working medium, so that the temperature is further reduced. At this time, since the low-temperature heat source of the absorption heat pump is the return water from the heat network, the temperature of the low-temperature heat source is increased compared to the circulating cooling water, so that the temperature rise range of the absorption heat pump is increased; then it enters the condenser (electric heat pump) for the first heating. Compared with the heat and power cogeneration system that only integrates the electric heat pump, the waste heat utilization of the evaporator (electric heat pump) will increase; then it enters the absorber, condenser (absorption heat pump) and peak heater in turn for heating, so as to realize the cascade utilization of energy and reduce heat exchange losses. Since the COP (coefficient of performance) of the electric heat pump is higher and more exhaust steam is recovered, the heating capacity of the unit and the overall efficiency of the system are improved; due to the increase in the amount of electricity used to drive the compressor, the new system always has a larger power generation adjustment range and power generation load adjustment rate than the traditional system. In addition, a diverter valve is installed at the hot water outlet of the system's electric heat pump condenser, and a mixing valve is installed at the hot water outlet of the absorption heat pump condenser to ensure that when the absorption heat pump fails, the cogeneration system can still operate normally using the electric heat pump and peak heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The schematic diagram of the structure of a combined heat and power system with an integrated heat pump.

[0014] In the figure: 1-medium pressure cylinder 2-first pressure control valve 3-second pressure control valve 4-low pressure cylinder 5-condenser 6-generator 7-condensing tower 8-second diverter valve 9-first condenser 10-absorber 11-second condenser 12-peak heater 13-second evaporator 14-first evaporator 15-compressor 16-first throttle valve 17-solution pump 18-generator 19-second throttle valve 20-first diverter valve 21-heat exchanger 22-third diverter valve 23-third throttle valve 24-fourth diverter valve 25-mixing valve. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with the accompanying drawings and some specific embodiments of the present invention.

[0016] A heat and power cogeneration system with integrated heat pump, characterized in that it includes a steam turbine system and a heat network water heating system;

[0017] The steam turbine system comprises an intermediate pressure cylinder (1), steam from the high pressure cylinder is connected to the inlet of the intermediate pressure cylinder (1), the outlet of the intermediate pressure cylinder (1) is connected to the inlet of a first diverter valve (20), the outlet of the first diverter valve (20) is connected to the inlets of a first pressure control valve (2) and a second pressure control valve (3), respectively, the outlet of the first pressure control valve (2) is connected to the inlet of a low pressure cylinder (4), the steam outlet of the low pressure cylinder (4) is connected to the steam inlet of a condenser (5), the condensate inlet of the condenser (5) is connected to the circulating cooling water outlet of a condensation tower (7), and the condensate outlet of the condenser (5) is connected to the inlet of a second diverter valve (8); the intermediate pressure cylinder (1), the low pressure cylinder (4) and the generator (6) are coaxially connected;

[0018] The hot water network heating system comprises a first condenser (9) of an electric heat pump, an absorber (10) of an absorption heat pump, a second condenser (11) and a peak heater (12); the outlet of the second diverter valve (8) is respectively connected to the inlet of circulating cooling water of a condensation tower (7) and the inlet of a heat source of a first evaporator (14), and the heat source outlet of the first evaporator (14) is connected to the inlet of circulating cooling water of the condensation tower (7); the refrigerant outlet of the first evaporator (14) is connected to the inlet of a compressor (15), and the outlet of the compressor (15) is connected to the first condenser (9). The inlet of the first condenser (9) is connected to the inlet of the first throttle valve (16), and the outlet of the first throttle valve (16) is connected to the refrigerant inlet of the first evaporator (14); the refrigerant outlet of the second evaporator (13) is connected to the inlet of the absorber (10), the weak solution outlet of the absorber (10) is connected to the solution pump (17), the heat exchanger (21) and the generator (18) in sequence, the concentrated solution outlet of the generator (18) is connected to the heat exchanger (21) and the second throttle valve (19) in sequence, and the outlet of the second throttle valve (19) is connected to the The concentrated solution inlet of the absorber (10) is connected, and the refrigerant outlet of the generator (18) is connected to the second condenser (11), the third throttle valve (23), and the second evaporator (13) in sequence; the outlet of the second pressure control valve (3) is connected to the inlet of the third diverter valve (22), and the outlet of the third diverter valve (22) is connected to the generator (18) and the peak heater (12) respectively; the heat network return water outlet is first connected to the heat source inlet of the second evaporator (13), and the heat source outlet of the second evaporator (13) is connected to the heat network water inlet of the first condenser (9). The hot water network outlet of the first condenser (9) is connected to the inlet of the fourth diverter valve (24), the outlet of the fourth diverter valve (24) is respectively connected to the inlet of the mixing valve (25) and the hot water network inlet of the absorber (10), the hot water network outlet of the absorber (10) is connected to the hot water network inlet of the second condenser (11), the hot water network outlet of the second condenser (11) is connected to the inlet of the mixing valve (25), the outlet of the mixing valve (25) is connected to the hot water network inlet of the peak heater (12), and the hot water network outlet of the peak heater (12) is connected to the hot network.

[0019] The return water from the heating network enters the low-temperature heat source inlet of the second evaporator (13) to heat the circulating medium, and then enters the water inlet of the first condenser (9) from the low-temperature heat source outlet of the second evaporator (13) to complete the first heating, and then enters the water inlet of the heating network of the absorber (10) from the water outlet of the first condenser (9) to complete the second heating, and then enters the water inlet of the heating network of the second condenser (11) from the water outlet of the heating network of the absorber (10) to complete the third heating, and finally enters the peak heater (12) from the water outlet of the heating network of the second condenser (11) to complete the fourth heating, and is used as the water supply for the heating network after reaching the required temperature.

[0020] Finally, it should be noted that the above examples are only used to illustrate the technical solution of the utility model rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.

Claims

1. A heat and power cogeneration system with integrated heat pump, characterized in that: Including steam turbine system and hot water heating system; The steam turbine system comprises an intermediate pressure cylinder (1), steam from the high pressure cylinder is connected to the inlet of the intermediate pressure cylinder (1), the outlet of the intermediate pressure cylinder (1) is connected to the inlet of a first diverter valve (20), the outlet of the first diverter valve (20) is connected to the inlets of a first pressure control valve (2) and a second pressure control valve (3), respectively, the outlet of the first pressure control valve (2) is connected to the inlet of a low pressure cylinder (4), the steam outlet of the low pressure cylinder (4) is connected to the steam inlet of a condenser (5), the condensate inlet of the condenser (5) is connected to the circulating cooling water outlet of a condensation tower (7), and the condensate outlet of the condenser (5) is connected to the inlet of a second diverter valve (8); the intermediate pressure cylinder (1), the low pressure cylinder (4) and the generator (6) are coaxially connected; The heat network water heating system comprises a first condenser (9) of an electric heat pump, an absorber (10) of an absorption heat pump, a second condenser (11) and a peak heater (12); the outlet of the second diverter valve (8) is respectively connected to the inlet of circulating cooling water of a condensation tower (7) and the inlet of a heat source of a first evaporator (14), and the heat source outlet of the first evaporator (14) is connected to the inlet of circulating cooling water of the condensation tower (7); The refrigerant outlet of the first evaporator (14) is connected to the inlet of the compressor (15), the outlet of the compressor (15) is connected to the inlet of the first condenser (9), the outlet of the first condenser (9) is connected to the inlet of the first throttle valve (16), and the outlet of the first throttle valve (16) is connected to the refrigerant inlet of the first evaporator (14); the refrigerant outlet of the second evaporator (13) is connected to the inlet of the absorber (10), the weak solution outlet of the absorber (10) is connected to the solution pump (17), the heat exchanger (21) and the generator (18) in sequence, the concentrated solution outlet of the generator (18) is connected to the heat exchanger (21) and the second throttle valve (19) in sequence, the outlet of the second throttle valve (19) is connected to the concentrated solution inlet of the absorber (10), the refrigerant outlet of the generator (18) is connected to the second condenser (11), the third throttle valve (23) and the second evaporator (13) in sequence; The outlet of the force control valve (3) is connected to the inlet of the third diverter valve (22), and the outlet of the third diverter valve (22) is respectively connected to the generator (18) and the peak heater (12); the hot network return water outlet is firstly connected to the heat source inlet of the second evaporator (13), the heat source outlet of the second evaporator (13) is connected to the hot network water inlet of the first condenser (9), the hot network water outlet of the first condenser (9) is connected to the inlet of the fourth diverter valve (24), the outlet of the fourth diverter valve (24) is respectively connected to the inlet of the mixing valve (25) and the hot network water inlet of the absorber (10), the hot network water outlet of the absorber (10) is connected to the hot network water inlet of the second condenser (11), the hot network water outlet of the second condenser (11) is connected to the inlet of the mixing valve (25), the outlet of the mixing valve (25) is connected to the hot network water inlet of the peak heater (12), and the hot network water outlet of the peak heater (12) is connected to the hot network.

2. The heat and power cogeneration system with integrated heat pump according to claim 1, characterized in that: The return water from the heating network enters the low-temperature heat source inlet of the second evaporator (13) to heat the circulating working fluid, and then enters the first condenser (9) heating network water inlet from the low-temperature heat source outlet of the second evaporator (13) to complete the first heating, and then enters the absorber (10) heating network water inlet from the first condenser (9) heating network water outlet to complete the second heating, and then enters the second condenser (11) heating network water inlet from the absorber (10) heating network water outlet to complete the third heating, and finally enters the peak heater (12) from the second condenser (11) heating network water outlet to complete the fourth heating, and is used as heating network water supply after reaching the required temperature requirement.

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