CN107830655A - The distributed energy resource system of summer in winter dual-use can be achieved - Google Patents

Abstract

The present invention relates to a kind of distributed energy resource system for realizing summer in winter dual-use.The present invention provides a kind of highly effective water water gas-fired heat pump waste heat recovery device, makes full use of the engine fume afterheat of gas-burning machine heat pump, and summer undertakes part air-conditioning refrigeration duty using fume afterheat driving BrLi chiller；Winter improves the supply water temperature of unit user side under worst cold case, realizes Effec-tive Function of the gas-burning machine heat pump in the winter time under worst cold case.Gas engine waste heat sufficiently rationally is utilized, significantly improves the performance of gas-burning machine heat pump.

Description

Distributed energy system that can realize dual-use of one machine in winter and summer

technical field

The invention belongs to the field of energy utilization, and in particular relates to a distributed energy system driven by natural gas and capable of realizing dual functions of one machine in winter and summer.

Background technique

The gas engine heat pump can efficiently utilize natural gas, reduce environmental pollution, effectively balance the seasonal load difference between winter and summer gas, reduce the peak power load in summer, and realize efficient use of high-quality energy, mainly due to the full use of waste heat from the gas engine, so analyze how Reasonable recovery and utilization of waste heat from gas engines is of great significance to improve the primary energy utilization rate of gas engine heat pumps.

Gas engine waste heat is mainly composed of three parts: cylinder liner cooling water waste heat, flue gas waste heat and engine radiation waste heat to the surrounding environment. The recyclable waste heat includes cylinder liner cooling water waste heat and part of flue gas waste heat. The cooling water temperature of gas engine affects the cooling efficiency of the engine, the heat load of high temperature parts, the heat distribution and energy utilization of the engine. The operation of gas engine when the cooling water temperature is lower than 65°C is supercooled operation, and supercooled operation will lead to the deterioration of the fuel combustion process and the wear of the cylinder liner. The gas engine is overheated when the cooling water temperature is higher than 95°C. At this time, the engine operating temperature is too high, which will also bring a series of hazards.

Contents of the invention

The invention provides a distributed energy system that can realize dual-use of one machine in winter and summer, which can make full use of the waste heat of the engine flue gas of the gas engine heat pump, and use the waste heat of the flue gas to drive the lithium bromide refrigeration unit to bear part of the cooling load of the air conditioner in summer; improve the low temperature working condition in winter The water supply temperature on the user side of the lower unit can realize the efficient operation of the gas engine heat pump under low temperature conditions in winter.

The technical solution adopted by the present invention to solve the technical problem is to provide a distributed energy system that can realize dual-use in winter and summer. The system includes a gas engine heat pump unit, an engine flue gas waste heat recovery device, a closed water storage Tube heat exchanger, open constant pressure expansion water tank, flue gas waste heat lithium bromide absorption refrigeration unit, electric three-way valve and cooling tower;

The cold/heat energy output end of the gas engine heat pump unit is directly connected to the user's air-conditioning terminal to provide users with cooling in summer and heating in winter;

When using in summer:

The cooling water outlet of the gas engine heat pump unit is connected to the cooling tower inlet through an electric three-way valve to dissipate its heat;

The high-temperature flue gas waste heat outlet of the gas engine heat pump unit is connected to the flue gas waste heat type lithium bromide absorption refrigeration unit inlet, and the flue gas waste heat type lithium bromide absorption refrigeration unit outlet is connected to the user's air conditioner terminal to provide cooling for the user in summer;

When using in winter:

The high-temperature flue gas waste heat outlet of the gas engine heat pump unit is also connected to the inlet of the engine flue gas waste heat recovery device, and the outlet of the engine flue gas waste heat recovery device is connected to the inlet of the closed water storage tank with a coil heat exchanger, and the closed water storage tank The outlet of the engine is connected with the inlet of the engine flue gas waste heat recovery device to form a heating cycle to provide heating and domestic water for users in winter;

The cooling water outlet of the gas engine heat pump unit is bypassed to the closed water storage tank with coil heat exchanger through the electric three-way valve, and the water outlet of the closed water storage tank is connected back to the gas engine heat pump unit to improve the efficiency of the gas engine heat pump unit in winter. water supply temperature.

The gas engine heat pump unit includes an engine and a compressor.

The present invention has the following beneficial effects:

(1) Reasonable and full utilization of gas engine waste heat can significantly improve the performance of gas engine heat pumps.

(2) It has practical guiding value for the popularization and improvement of gas engine heat pump system.

(3) Realize the high-efficiency combination of heat recovery devices, and further improve the utilization rate of primary energy. Compared with gas-fired boilers, the utilization rate of primary energy can be increased by more than 70%.

(4) Under the same gas consumption, the heat supply of the gas engine heat pump is about 1.8 times that of the gas boiler.

Description of drawings

Figure 1 is a schematic diagram of the inventive system.

In the figure: 1. Gas engine heat pump unit; 2. Gas engine part of the unit; 3. Compressor part of the unit; 4. Engine flue gas waste heat recovery device; 5. Closed water storage tank; 6. Coil heat exchanger; 7. Open type constant pressure expansion water tank; 8. Flue gas waste heat type lithium bromide absorption refrigeration unit; 9. Filter; 10. Circulating water pump; 11. Check valve; 12. Butterfly valve; 13. Make up water tank; 14. Water softener; 15 , Electric three-way valve; 16, cooling tower.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 1, it is a schematic diagram of the system of the present invention.

The gas engine heat pump is dual-purpose in winter and summer, and the cold (hot) water supply and return pipeline of the heat pump host is actually a set of pipelines for winter and summer. The engine flue gas waste heat recovery device 4 can only produce hot water in winter and summer, so this scheme divides the cold (hot) water supply and return pipeline of the heat pump main engine and the supply and return water pipeline of the engine flue gas waste heat recovery device 4 into two parts. road system, the two are not mixed, and the engine flue gas waste heat recovery device 4 is only used for heating in winter. In summer, the high-temperature flue gas produced by the gas engine will pass through the flue gas waste heat type lithium bromide unit 8 to produce cold water for air conditioning or process.

Considering that the air-conditioning system is mainly for cooling in summer, and the heat is relatively abundant, the cooling heat of the gas engine of the gas engine heat pump is not recovered throughout the year, and its engine cooling water pipeline is incorporated into the cooling water system of the gas engine heat pump condenser. During the cooling cycle in summer, the engine cooling waste heat is discharged to the outdoor atmosphere with the cooling tower 16, and during the heating cycle in winter, it is used as an auxiliary heat source for heat pump heating when the outdoor ambient temperature is too low.

Since the cooling tower 16 is an open water system, it is easy to cause algae and bacterial pollution, so the gas engine cooling water system does not mix with the user's closed water system. Through the combined action of the closed water storage tank 5 with the coil heat exchanger 6 and the electric three-way valve 15, the cooling water supply temperature of the unit in winter low-temperature working conditions is increased, which not only ensures the stability of the water supply temperature for users and the water quality of the water system, The waste heat of the flue gas from the gas engine is used to ensure the efficient operation of the unit under low temperature conditions in winter.

When the present invention works in summer:

1) The chilled water produced by the gas engine heat pump unit 1 in summer is supplied to the air-conditioning users (the configuration of pipelines and auxiliary equipment is the same as that of the water system of the current central air-conditioning chiller).

2) The side of the electric three-way valve 15 is normally closed (no heat exchange with the closed water storage tank 5 with coil heat exchanger 6), the cooling water of the gas engine and the cooling water of the main engine are sent to the cooling tower 16 on the roof under the action of the circulation pump. The outdoor atmospheric environment dissipates heat.

3) Flue gas waste heat lithium bromide refrigerating unit 8 is driven by high temperature flue gas waste heat of the engine. Lithium bromide solution is used as absorbent and water is used as refrigerant to produce cold water for air conditioning or process, and undertake part of the cooling capacity of the gas heat pump unit.

When the present invention works in winter:

1) Gas engine heat pump unit 1 heats in winter and generates hot water to supply air conditioners (the configuration of pipelines and auxiliary equipment is the same as that in summer).

2) The cooling water in the engine flue gas heat recovery device 4 absorbs heat from the engine flue gas heat recovery device 4, and returns to the closed water storage tank 5 with the coil heat exchanger 6 after being heated by the user, and then circulated by the circulating water 10 Send it back to the engine flue gas heat recovery device for 4-line circulation heating to provide heating and domestic hot water for the user.

3) When the ambient temperature is too low in winter, use part of the heat of the gas engine cooling water and engine flue gas heat recovery device 4 to increase the water supply temperature of the gas engine heat pump evaporator (actually the condenser of the summer refrigeration cycle) in winter to ensure that the gas engine Efficient operation of heat pumps under low temperature conditions in winter. When the circulating water of the gas engine heat pump evaporator in winter (actually the condenser of the summer refrigeration cycle) is mixed with the cooling water of the engine (which has absorbed the waste heat of the engine) and the water temperature has not yet reached the rated requirement after the test, the electric three-way valve 15 When it is turned on, part of the circulating water enters the closed water storage tank 5 with coil heat exchanger 6, and is heated through the coil heat exchanger 6 and the hot user return water in the water tank (equivalent to absorbing the waste heat in the flue gas recovery device again). After heat exchange absorbs heat and raises the temperature, it returns to directly supply the gas engine heat pump evaporator (actually the summer refrigeration cycle condenser).

Claims (1)

1. the distributed energy resource system of summer in winter dual-use can be realized, it is characterised in that the system includes gas-burning machine heat pump unit (1), gas-burning machine heat pump unit (1) includes engine (2) and compressor (3), engine flue gas waste heat recoverer (4), enclosed storage Water tank (5), coil heat exchanger (6), open type level pressure expansion tank (7), fume afterheat type lithium bromide absorption refrigerating set (8), Electric T-shaped valve (15) and cooling tower (16)；

The cold heat energy output end of gas-burning machine heat pump unit (1) is directly connected to as user's summer cooling winter with user's conditioner terminal air Heat supply；

When summer uses：

The coolant outlet of gas-burning machine heat pump unit (1) is connected to diffuse by electric T-shaped valve (15) with cooling tower (16) entrance Its heat；

The high-temperature flue gas waste heat outlet of gas-burning machine heat pump unit (1) enters with fume afterheat type lithium bromide absorption refrigerating set (8) Mouthful connection, the outlet of fume afterheat type lithium bromide absorption refrigerating set (8) and user's conditioner terminal air are connected as user's summer and supplied It is cold；

When winter uses：

The entrance that the high-temperature flue gas waste heat of gas-burning machine heat pump unit (1) exports also with engine flue gas waste heat recoverer (4) is connected, The outlet of engine flue gas waste heat recoverer (4) is connected with enclosed water storage tank (5) entrance with coil heat exchanger (6), enclosed It is user's winter that the outlet of water storage tank (5), which is connected with the entrance of engine flue gas waste heat recoverer (4) so as to form heat cycles, Heating and offer domestic water；

The coolant outlet of gas-burning machine heat pump unit (1) is connected to coil heat exchanger by electric T-shaped valve (15) bypass (6) enclosed water storage tank (5), the delivery port of enclosed water storage tank (5) connect back to gas-burning machine heat pump unit (1) to improve winter combustion gas The supply water temperature of machine source pump (1).