Natural gas distributed energy - ground source heat pump energy supply system

Abstract

The application discloses a natural gas distributed energy source-ground source heat pump energy supply system, which comprises a gas internal combustion generator set, a flue gas type lithium bromide absorption unit, a waste heat boiler, a heat storage water tank, a flue gas condensing heat exchanger and a ground source heat pump unit. The gas inlet of the gas internal combustion generator set is connected with a gas pipeline. The cylinder jacket water outlet and the high-temperature flue gas outlet of the gas internal combustion generator set are respectively connected with the low-temperature generator and the high-temperature generator of the flue gas type lithium bromide absorption unit through a cylinder jacket water pipe and a high-temperature flue gas pipe. The low-temperature generator and the high-temperature generator of the flue gas type lithium bromide absorption unit are respectively connected with an air conditioning unit through an air conditioning side water supply pipe and an air conditioning side return water pipe. The system of the application is simple in structure, and can realize independent or combined cooling or heating of the ground source heat pump system and the distributed energy source system through valve conversion, and simultaneously provide the required domestic hot water at the terminal.

Description

Technical Field

[0001] This invention relates to a natural gas distributed energy - ground source heat pump energy supply system, belonging to the field of distributed energy technology. Background Technology

[0002] With socio-economic development and the improvement of people's living standards, my country's energy demand has risen sharply. In the current climate of increasing environmental awareness, expanding the use of renewable and clean energy has become a major approach to energy application.

[0003] Chinese utility model patent application number 201520858728.8 discloses a combined energy supply system of natural gas distributed energy and ground source heat pump. This system organically combines natural gas distributed energy and geothermal energy. The electricity required to operate the ground source heat pump is provided by a gas internal combustion engine. The ground source heat pump and natural gas distributed energy system complement each other, saving land area in the power plant's entire energy supply system, conserving water resources, and reducing noise pollution. However, this patent's combined energy supply only utilizes the electricity generated by the internal combustion engine in the distributed energy supply system for the ground source heat pump unit. It does not adequately utilize the high-temperature flue gas and high-temperature cylinder liner water emitted by the internal combustion engine, resulting in low primary energy utilization efficiency.

[0004] Chinese utility model patent application number 201320288530.1 discloses a combined energy supply system based on natural gas distributed energy and ground source heat pump. This system connects the municipal power grid to the electricity generated by the gas turbine generator set through a power distribution system to supply power to the entire system. Simultaneously, it utilizes the high-temperature cylinder liner water and high-temperature flue gas generated by the gas turbine generator set to produce domestic hot water. Although the patent allows the electric chiller unit, ground source heat pump unit, and lithium bromide unit to be combined to supply energy to the end of the system, the degree of combined utilization is relatively low.

[0005] Chinese invention patent application number 201210142139.0 discloses a composite energy supply system coupling a natural gas-based distributed energy system with a ground source heat pump. This system fully utilizes the waste heat of the distributed energy system and integrates both clean fossil energy and renewable energy technologies through coupling and integration, achieving the synergistic advantages of the two energy sources and improving the overall energy system efficiency. However, this system has high equipment redundancy, high system complexity, high investment costs, and high operating costs. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a natural gas distributed energy - ground source heat pump energy supply system. This system has simple equipment and can achieve cooling or heating by switching valves between the ground source heat pump system and the distributed energy system, either individually or in combination, while simultaneously providing the domestic hot water required at the terminal.

[0007] The technical solution of this invention: A natural gas distributed energy-ground source heat pump power supply system, comprising a gas-fired internal combustion generator set, a flue gas type lithium bromide absorption chiller, a waste heat boiler, a hot water storage tank, a flue gas condensing heat exchanger, and a ground source heat pump unit. The air inlet of the gas-fired internal combustion generator set is connected to a gas pipeline. The cylinder liner water outlet and high-temperature flue gas outlet of the gas-fired internal combustion generator set are respectively connected to the low-temperature generator and high-temperature generator of the flue gas type lithium bromide absorption chiller through cylinder liner water pipes and high-temperature flue gas pipes. The low-temperature generator and high-temperature generator of the flue gas type lithium bromide absorption chiller are respectively connected to an air conditioning unit through an air conditioning side water supply pipe and an air conditioning side return pipe. Simultaneously, the high-temperature generator of the flue gas type lithium bromide absorption chiller is connected to the waste heat boiler through a primary medium-temperature flue gas pipe. The inlet of the waste heat boiler is connected to the municipal water supply pipe, and the outlet of the waste heat boiler is connected to the inlet of the hot water storage tank via a hot water pipe. The outlet of the hot water storage tank is connected to the domestic hot water supply pipe. The waste heat boiler is connected to the inlet of the flue gas condensing heat exchanger via a two-stage medium-temperature flue gas pipe. An exhaust flue gas pipe is connected to the outlet of the flue gas condensing heat exchanger. The inlet of the flue gas condensing heat exchanger is connected to the ground source side water supply pipe, and the outlet of the flue gas condensing heat exchanger is connected to the ground source heat pump unit via a warm water pipe. The outlet of the ground source heat pump unit is connected to the air conditioning side water supply pipe via a drain pipe. A first valve is installed on the ground source side water supply pipe, and a fifth valve and a seventh valve are installed on the warm water pipe. A third valve is connected in parallel between the inlet of the first valve and the outlet of the fifth valve.

[0008] Furthermore, another inlet of the ground source heat pump unit is connected to the air conditioning side return water pipe, and another outlet of the ground source heat pump unit is connected to another inlet of the flue gas condensing heat exchanger through a cold water pipe. The other outlet of the flue gas condensing heat exchanger is connected to the ground source side return water pipe. A second valve is installed on the ground source side return water pipe, and a sixth valve and an eighth valve are installed on the cold water pipe. A fourth valve is connected in parallel between the inlet of the sixth valve and the outlet of the second valve.

[0009] Furthermore, the cryogenic generator of the flue gas type lithium bromide absorption unit is connected to the cylinder liner inlet of the gas-fired internal combustion generator unit through a cryogenic return water pipe.

[0010] Due to the adoption of the above technical solution, the advantages of this invention are as follows: The system equipment of this invention is simple, and the ground source heat pump system and the distributed energy system can be used to provide cooling or heating independently or in combination through valve switching, while simultaneously providing the domestic hot water required at the terminal. Under winter operating conditions, it can effectively improve the coefficient of performance of the ground source heat pump unit and increase the system operating efficiency. Especially when the ground source is soil, heat can be supplemented to the ground source side, solving the serious cooling and heating imbalance problem that exists in the application of soil source heat pump systems in northern regions. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the present invention;

[0012] The attached diagram is labeled as follows: 1-Gas-fired internal combustion generator set; 2-Flue gas type lithium bromide absorption chiller; 3-Waste heat boiler; 4-Hot water storage tank; 5-Flue gas condensing heat exchanger; 6-Ground source heat pump unit; 7-First valve; 8-Second valve; 9-Third valve; 10-Fourth valve; 11-Fifth valve; 12-Sixth valve; 13-Seventh valve; 14-Eighth valve; 15-Gas pipeline; 16-Cylinder liner water pipe; 17-High temperature flue gas pipe; 18-Air conditioning side water supply pipe; 19-First-stage medium-temperature flue gas pipe; 20-Air conditioning side return water pipe; 21-Municipal water supply pipe; 22-Second-stage medium-temperature flue gas pipe; 23-Exhaust flue gas pipe; 24-Ground source side water supply pipe; 25-Warm water pipe; 26-Drainage pipe; 27-Cold water pipe; 28-Ground source side return water pipe; 29-Domestic hot water supply pipe; 30-Low temperature return water pipe; 31-Hot water pipe. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0014] An embodiment of the present invention: A schematic diagram of the structure of a natural gas distributed energy - ground source heat pump energy supply system is shown below. Figure 1As shown, the system includes a gas-fired internal combustion generator set 1, a flue gas type lithium bromide absorption chiller 2, a waste heat boiler 3, a hot water storage tank 4, a flue gas condensing heat exchanger 5, and a ground source heat pump unit 6. The gas-fired internal combustion generator set 1 has its air inlet connected to a gas pipeline 15. The cylinder liner water outlet and high-temperature flue gas outlet of the gas-fired internal combustion generator set 1 are connected to the low-temperature generator and high-temperature generator of the flue gas type lithium bromide absorption chiller 2 through the cylinder liner water pipe 16 and the high-temperature flue gas pipe 17, respectively. The low-temperature generator and high-temperature generator of the flue gas type lithium bromide absorption chiller 2 are connected to an air conditioning unit through the air conditioning side water supply pipe 18 and the air conditioning side return water pipe 20, respectively. At the same time, the high-temperature generator of the flue gas type lithium bromide absorption chiller 2 is connected to the waste heat boiler 3 through a first-stage medium-temperature flue gas pipe 19. The low-temperature generator of the flue gas type lithium bromide absorption chiller 2 is connected to the cylinder liner water inlet of the gas-fired internal combustion generator set 1 through a low-temperature return water pipe 30. The inlet of the waste heat boiler 3 is connected to the municipal water supply pipe 21, and the outlet of the waste heat boiler 3 is connected to the inlet of the hot water storage tank 4 through the hot water pipe 31. The outlet of the hot water storage tank 4 is connected to the domestic hot water supply pipe 29. The waste heat boiler 3 is connected to the inlet of the flue gas condensing heat exchanger 5 through the secondary medium-temperature flue gas pipe 22. An exhaust flue gas pipe 23 is connected to the outlet of the flue gas condensing heat exchanger 5. The inlet of the flue gas condensing heat exchanger 5 is connected to the ground source side water supply pipe 24, and the outlet of the flue gas condensing heat exchanger 5 is connected to the ground source heat pump unit 6 through the warm water pipe 25. The outlet of the ground source heat pump unit 6 is connected to the air conditioning side water supply pipe 18 through the drain pipe 26. A first valve 7 is installed on the ground source side water supply pipe 24, and a fifth valve 11 and a seventh valve 13 are installed on the warm water pipe 25 respectively. A third valve 9 is connected in parallel between the inlet of the first valve 7 and the outlet of the fifth valve 11. Another inlet of the ground source heat pump unit 6 is connected to the air conditioning side return water pipe 20. Another outlet of the ground source heat pump unit 6 is connected to another inlet of the flue gas condensing heat exchanger 5 through the cold water pipe 27. Another outlet of the flue gas condensing heat exchanger 5 is connected to the ground source side return water pipe 28. A second valve 8 is installed on the ground source side return water pipe 28. A sixth valve 12 and an eighth valve 14 are installed on the cold water pipe 27. A fourth valve 10 is connected in parallel between the inlet of the sixth valve 12 and the outlet of the second valve 8.

[0015] The working principle of this invention is as follows: Gas enters the gas-fired internal combustion generator set 1 through the gas pipeline 15 for combustion and power generation. The cylinder liner water and high-temperature flue gas generated by the gas-fired internal combustion generator set 1 enter the low-temperature generator and high-temperature generator of the flue gas type lithium bromide absorption chiller 2 for cooling, providing the chilled water required by the air conditioning unit terminal. The flue gas from the high-temperature generator enters the waste heat boiler 3 to heat the municipal tap water, and then enters the flue gas condenser heat exchanger 5 for heat exchange. Finally, it is discharged through the exhaust flue gas pipe 23 on the flue gas condenser heat exchanger 5.

[0016] Summer operating conditions: Valve 7 and 8 are closed; valves 9 and 10 are open; valves 11 and 12 are closed; and valves 13 and 14 are open. The ground source heat pump unit 6 can provide cooling either alone or in conjunction with the flue gas type lithium bromide absorption chiller unit 2.

[0017] Winter operating condition: Valve 7 and 8 are open; valves 9 and 10 are closed; valves 11 and 12 are open; and valves 13 and 14 are closed. The ground source side inlet water exchanges heat with the flue gas from the waste heat boiler 3 in the flue gas condensing heat exchanger 5, increasing the ground source side water supply temperature and thus improving the coefficient of performance (COP) of the ground source heat pump unit. Under this condition, the ground source heat pump unit can provide heating either alone or in conjunction with the flue gas-type lithium bromide absorption chiller 2.

[0018] Transitional season operating conditions: First valve 7 and second valve 8 are open; third valve 9 and fourth valve 10 are closed; fifth valve 11 and sixth valve 12 are closed; seventh valve 13 and eighth valve 14 are closed. The ground source heat pump unit stops operating, and the flue gas type lithium bromide absorption unit 2 supplies cooling or heating to the end of the system, while simultaneously supplementing heat to the ground source side through the flue gas condensing heat exchanger 5.

Claims

1. A natural gas distributed energy-ground source heat pump power supply system, comprising a gas-fired internal combustion generator set (1), a flue gas type lithium bromide absorption chiller (2), a waste heat boiler (3), a hot water storage tank (4), a flue gas condensing heat exchanger (5), and a ground source heat pump unit (6), characterized in that: The gas-fired internal combustion generator set (1) has its air inlet connected to a gas pipeline (15). The cylinder liner water outlet and high-temperature flue gas outlet of the gas-fired internal combustion generator set (1) are connected to the low-temperature generator and high-temperature generator of the flue gas type lithium bromide absorption chiller (2) through the cylinder liner water pipe (16) and high-temperature flue gas pipe (17), respectively. The low-temperature generator and high-temperature generator of the flue gas type lithium bromide absorption chiller (2) are connected to the air conditioning unit through the air conditioning side water supply pipe (18) and air conditioning side water return pipe (20), respectively. At the same time, the high-temperature generator of the flue gas type lithium bromide absorption chiller (2) is connected to the waste heat boiler (3) through the first-stage medium-temperature flue gas pipe (19). The water inlet of the waste heat boiler (3) is connected to the municipal water supply pipe (21). The water outlet of the waste heat boiler (3) is connected to the water inlet of the hot water storage tank (4) through the hot water pipe (31). The outlet is connected to the domestic hot water supply pipe (29). The waste heat boiler (3) is connected to the inlet of the flue gas condensing heat exchanger (5) through the secondary medium temperature flue gas pipe (22). An exhaust flue gas pipe (23) is connected to the outlet of the flue gas condensing heat exchanger (5). The inlet of the flue gas condensing heat exchanger (5) is connected to the ground source side water supply pipe (24). The outlet of the flue gas condensing heat exchanger (5) is connected to the ground source heat pump unit (6) through the warm water pipe (25). The outlet of the ground source heat pump unit (6) is connected to the air conditioning side water supply pipe (18) through the drain pipe (26). A first valve (7) is installed on the ground source side water supply pipe (24). A fifth valve (11) and a seventh valve (13) are installed on the warm water pipe (25). A third valve (9) is connected in parallel between the inlet of the first valve (7) and the outlet of the fifth valve (11). The other inlet of the ground source heat pump unit (6) is connected to the air conditioning side return water pipe (20), and the other outlet of the ground source heat pump unit (6) is connected to the other inlet of the flue gas condensing heat exchanger (5) through the cold water pipe (27). The other outlet of the flue gas condensing heat exchanger (5) is connected to the ground source side return water pipe (28). A second valve (8) is installed on the ground source side return water pipe (28), and a sixth valve (12) and an eighth valve (14) are installed on the cold water pipe (27). A fourth valve (10) is connected in parallel between the inlet of the sixth valve (12) and the outlet of the second valve (8). The low-temperature generator of the flue gas type lithium bromide absorption unit (2) is connected to the cylinder liner inlet of the gas internal combustion generator set (1) through the low-temperature return water pipe (30). Summer operating conditions: First valve (7) and second valve (8) are closed, third valve (9) and fourth valve (10) are open, fifth valve (11) and sixth valve (12) are closed, seventh valve (13) and eighth valve (14) are open, and the ground source heat pump unit (6) can provide cooling alone or in combination with the flue gas type lithium bromide absorption unit (2); Winter operating condition: First valve (7) and second valve (8) are open, third valve (9) and fourth valve (10) are closed, fifth valve (11) and sixth valve (12) are open, seventh valve (13) and eighth valve (14) are closed. The water inlet on the ground source side exchanges heat with the flue gas from the waste heat boiler (3) in the flue gas condensing heat exchanger (5) to increase the water supply temperature on the ground source side. Under this operating condition, the ground source heat pump unit (6) can provide heating alone or in combination with the flue gas type lithium bromide absorption unit (2). Transitional season operating conditions: First valve (7) and second valve (8) are open, third valve (9) and fourth valve (10) are closed, fifth valve (11) and sixth valve (12) are closed, seventh valve (13) and eighth valve (14) are closed, ground source heat pump unit (6) stops operating, and flue gas type lithium bromide absorption unit (2) supplies cooling or heating to the end of the system, while supplementing heat to the ground source side through flue gas condensing heat exchanger (5).

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