An air conditioning system and control method for improving waste heat utilization of wide temperature range air source heat pump

Abstract

The present invention discloses an air-conditioning system and a control method for improving the utilization of waste heat from a wide-temperature-range air-source heat pump. The system recycles the engine's exhaust gas at 80°C through another cooling water system. The recovered heat is either used by a heat pump system to improve heating capacity and efficiency or sent to the outer surface of a heat exchanger, which can effectively reduce the frosting rate or perform defrosting, and can also improve part of the heating capacity of the unit. When the heat of the 80°C exhaust gas is absorbed and converted into low-temperature gas for discharge, white smoke will not occur.

Description

Technical Field

[0001] The invention discloses a wide temperature range air source heat pump air conditioning system, in particular to an air conditioning system and a control method for improving the utilization of waste heat of a wide temperature range air source heat pump, belonging to the technical field of heat pumps. Background Art

[0002] At present, heat pump technology has been widely used in various fields of society / production / life. Among them, gas-to-air source heat pump (hereinafter referred to as "gas heat pump") technology has just started to develop in China in recent years. The cylinder liner heat generated by the power component engine during operation and the exhaust gas waste heat are not fully utilized. The reason is that the engine cooling water temperature needs to be maintained at around 80°C according to the design requirements, resulting in the final exhaust gas temperature being around 80°C. Therefore, 20%~30% of the heat generated by energy combustion is discharged into the air in the form of exhaust gas, which is not fully utilized, resulting in waste. Therefore, the heating efficiency of the equipment is low; secondly, when the heat pump technology is running for heating in winter, frequent frosting / defrosting will also lead to a decrease in the heating efficiency of the unit; finally, the exhaust gas at around 80°C will turn into water vapor when it encounters low-temperature air, forming white smoke, causing adverse effects. Summary of the invention

[0003] In view of the above-mentioned shortcoming of low heating efficiency of gas heat pumps in the prior art, the present invention provides an air-conditioning system and control method for improving the utilization of waste heat from air source heat pumps in a wide temperature range. The system recycles the engine's exhaust gas at 80°C through another cooling water system. The recovered heat is either used by the heat pump system to improve heating capacity and efficiency or sent to the outer surface of the heat exchanger, which can effectively reduce the frosting rate or perform defrosting, and can also improve the heating capacity of some parts of the unit. When the heat of the 80°C exhaust gas is absorbed and converted into low-temperature gas for discharge, white smoke will not occur.

[0004] The technical solution adopted by the present invention to solve its technical problem is: an air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump, the system includes an air conditioning heat exchange system, a first cooling water system and a second cooling water system, the first cooling water system is connected to the gas engine cooling system in the air conditioning heat exchange system, and the second cooling water system is connected to the exhaust end of the gas engine in the air conditioning heat exchange system, wherein:

[0005] The air conditioning heat exchange system includes a gas engine, a compressor, an oil separator, a four-way valve, a first heat exchanger, a refrigerant heat exchanger and a gas-liquid separator. The compressor is connected to the gas engine, the refrigerant output end of the compressor is connected to the input end of the oil separator, the refrigerant output end of the oil separator is connected to the first heat exchanger through the four-way valve, the output end of the first heat exchanger is connected to the refrigerant heat exchanger, the output end of the refrigerant heat exchanger is connected to the gas-liquid separator through the four-way valve, the output end of the gas-liquid separator is connected to the input end of the compressor, the output end of the first heat exchanger is divided into two paths, the first path is connected to the refrigerant heat exchanger through the electronic expansion valve EXV1, the second path is connected to the refrigerant input end of the fifth heat exchanger through the electronic expansion valve EXV2, and the refrigerant output end of the fifth heat exchanger is connected to the gas-liquid separator input end;

[0006] The first cooling water system includes a second heat exchanger, a thermostat T1, a thermostat T2, a first water pump, a first filter and a first cooling water radiator. The cooling water output end of the gas engine is connected to the a1 end of the thermostat T1. The output end of the thermostat T1 is divided into two paths, one path of the c1 end is connected to the first cooling water radiator, and one path of the b1 end is connected to the thermostat T2. The output end of the first cooling water radiator is connected to the first filter. The output end of the thermostat T2 is divided into two paths, one path of the e1 end is connected to the second heat exchanger, the output end of the second heat exchanger is connected to the first filter, and one path of the d1 end is directly connected to the first filter. The output end of the first filter is connected to the first water pump. The first water pump is connected to the first cooling water input end of the gas engine through the third heat exchanger. The second heat exchanger is connected to the air-conditioning water outlet and the air-conditioning water inlet of the first heat exchanger. A solenoid valve SV10 is connected between the second heat exchanger and the air-conditioning water outlet of the first heat exchanger.

[0007] The second cooling water system includes a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a sixth heat exchanger, a second filter, a second water pump, a thermostat T3, a three-way valve and a second cooling water radiator. The third heat exchanger is connected to the exhaust gas output end of the gas engine, the first input end of the fourth heat exchanger is connected to the third heat exchanger, the second input end of the fourth heat exchanger is divided into three paths after passing through the second water pump and the second filter, the first path is connected to the b3 end of the thermostat T3, the a3 end of the thermostat T3 is connected to the second output end of the fourth heat exchanger, the second path is connected to the input end of the fifth heat exchanger, the output end of the fifth heat exchanger is connected to the e3 end of the three-way valve, the third path is connected to the input end of the second cooling water radiator, the output end of the second cooling water radiator is connected to the f3 end of the three-way valve, the d3 section of the three-way valve is connected to the c3 end of the thermostat T3, the first output end of the fourth heat exchanger is connected to the sixth heat exchanger, and the output of the sixth heat exchanger is connected to the exhaust gas input end of the gas engine.

[0008] A control method for an air conditioning system that improves the utilization of waste heat from a wide temperature range air source heat pump is implemented by using the air conditioning system that improves the utilization of waste heat from a wide temperature range air source heat pump as described above. The control method includes two modes: heating operation and cooling operation.

[0009] During heating operation, the gas engine burns natural gas to drive the compressor to operate. The compressor compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant, and then passes through the oil separator to separate the refrigerant and the lubricating oil. Then, it passes through the four-way valve to reach the first heat exchanger for heat exchange, heating the air-conditioning circulating water to become a medium-temperature, high-pressure liquid refrigerant. Then, it is divided into two paths. One path is throttled by the electronic expansion valve EXV1, and then absorbs heat from the air in the outdoor heat exchanger to become a low-temperature, low-pressure gaseous refrigerant. The other path is throttled by the electronic expansion valve EXV2 and then enters the fifth The heat exchanger absorbs the heat from the high-temperature cooling water and turns it into a low-temperature, low-pressure gaseous refrigerant. Then, the low-temperature, low-pressure gaseous refrigerants of the two routes merge and pass through a gas-liquid separator to separate the gaseous refrigerant from the liquid refrigerant. The low-temperature, low-pressure gaseous refrigerant returns to the compressor for compression again. In this cycle, the air-conditioning water inlet pipe will be divided into two routes for heating. One route exchanges heat with the high-temperature refrigerant in the first heat exchanger, and the other route controls the solenoid valve SV10 to open and exchanges heat with the high-temperature cooling water in the second heat exchanger. Finally, the two routes of heated air-conditioning water merge and are sent out from the air-conditioning water outlet pipe.

[0010] During heating operation, in the first cooling water system, the control solenoid valve SV10 is opened, and the heat of the cooling water is taken away by the air-conditioning water in the second heat exchanger. When the cooling water temperature is lower than T1°C and greater than T2°C, the a1 and b1 channels of the thermostat T1 are turned on, and the b1 and d1 channels of the thermostat T2 and the b1 and e1 channels of the thermostat T2 are turned on. After the cooling water absorbs the heat of the exhaust gas from the third heat exchanger, it passes through the thermostat T1 and the thermostat T2 in sequence and is divided into two paths. One part is absorbed by the air-conditioning water in the second heat exchanger through the b1 and e1 channels, and the other part is directly bypassed through the b1 and d1 channels. The two cooling waters are mixed and returned to the inlet of the first water pump, and are sent to the third heat exchanger to absorb heat again through the first water pump, and the cycle is repeated.

[0011] During heating operation, in the second cooling water system, the second water pump runs to send cooling water to the fourth heat exchanger for heat exchange, absorbs heat in the exhaust gas, and becomes high-temperature cooling water. It is then judged by the thermostat T3. When the water temperature is lower than T3, the a3 and b3 channels of the thermostat T3 are turned on, and the a3 and c3 channels are closed. When the water temperature is higher than T3 and lower than T3+5℃, the a3 and b3 channels and the a3 and c3 channels of the thermostat T3 are turned on. When the water temperature is higher than T3+5℃, the a3 and c3 channels of the thermostat T3 are turned on, and the a3 and b3 channels of the thermostat T3 are not turned on. Among them, the a3 and b3 channels are turned on. The cooling water is directly returned to the inlet of the second water pump and sent to the fourth heat exchanger for heating again to maintain the minimum water temperature at about T3℃. After the a3 and c3 channels are connected, the three-way valve is used for judgment. When the ambient temperature T4 is between 0℃±5℃ or the unit is in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be connected to send the cooling water heat to the second cooling water radiator for heat dissipation. When the ambient temperature T4 is less than -5℃, or greater than 5℃ and the unit is not in the defrosting stage, the three-way valve d3 and e3 channels are controlled to be connected to send the cooling water heat to the fifth heat exchanger to be absorbed by the low-temperature refrigerant of the heat pump system.

[0012] During heating operation, in the engine intake / exhaust system, the fresh air at the air intake first exchanges heat with the engine exhaust gas through the sixth heat exchanger to increase its temperature, exchanges heat with the cooling water in the first cooling water system in the third heat exchanger, and dissipates the heat to the first cooling water system. The exhaust gas exchanges heat with the cooling water in the second cooling water system through the fourth heat exchanger, and dissipates the heat to the second cooling water system again. It exchanges heat with the low-temperature fresh air in the sixth heat exchanger and is discharged into the air.

[0013] During heating operation, when the ambient temperature T4 is between 0℃±5℃ or the unit is in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be connected, and the heat of the cooling water is sent to the second cooling water radiator for heat exchange with the fresh air, and the air temperature rises; when the ambient temperature T4 is less than -5℃, or greater than 5℃, and is not in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be closed, and the air temperature remains unchanged after the fresh air exchanges heat with the second cooling water radiator. Subsequently, the air exchanges heat with the first heat exchanger of the refrigerant, and the heat is absorbed by the low-temperature gaseous refrigerant, and the temperature of the fresh air decreases; finally, after the air exchanges heat with the first cooling water radiator, the temperature of the fresh air remains unchanged, because the solenoid valve SV10 is open, and the heat is taken away by the second heat exchanger. When the temperature is lower than T1℃, the a1 and c1 channels of the thermostat T1 are closed, so there is no heat input to the first cooling water radiator;

[0014] During refrigeration operation, the gas engine burns natural gas to drive the compressor to run. The compressor compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The refrigerant passes through the oil separator to separate the refrigerant from the lubricating oil. The refrigerant then passes through the four-way valve to the first refrigerant heat exchanger to exchange heat with the air. The high-temperature, high-pressure gaseous refrigerant absorbs heat from the air and becomes a medium-temperature, high-pressure liquid refrigerant. After being throttled by the electronic expansion valve EXV1, the refrigerant absorbs heat from the air-conditioning water in the first heat exchanger and becomes a low-temperature, low-pressure gaseous refrigerant. , the other electronic expansion valve EXV2 is closed, the fifth heat exchanger does not work, then, the low-temperature, low-pressure gaseous refrigerant coming out of the first heat exchanger passes through the four-way valve to separate the gaseous refrigerant from the liquid refrigerant in the gas-liquid separator, and the low-temperature, low-pressure gaseous refrigerant returns to the compressor for compression again, and the cycle continues; the air-conditioning inlet water is cooled after heat exchange with the low-temperature refrigerant in the first heat exchanger, and the other control solenoid valve SV10 is closed, then the second heat exchanger does not work, and the cooled air-conditioning water is sent out from the air-conditioning outlet pipe;

[0015] During refrigeration operation, in the first cooling water system, the solenoid valve SV10 is controlled to be closed. When the cooling water temperature is higher than T1°C, the a1 and b1 channels and a1 and c1 channels of the thermostat T1 are turned on, and the b1 and e1 channels of the thermostat T2 are turned on. After the cooling water absorbs the exhaust heat from the third heat exchanger, it is divided into two paths after passing through the thermostat T1. One part passes through the a1 and c1 channels of the thermostat T1 and is taken away by the air in the first cooling water heat dissipation to reduce the cooling water temperature. The other part passes through the a1 and b1 channels of the thermostat T1 and the b1 and e1 channels of the thermostat T2 and passes through the second heat exchanger without heat exchange. The two cooling waters are mixed and returned to the inlet of the first water pump, and are sent to the third heat exchanger again through the first water pump to absorb heat, and the cycle is repeated.

[0016] During refrigeration operation, in the second cooling water system, the second water pump does not operate, the exhaust gas does not exchange heat in the fourth heat exchanger, and the second cooling water system does not operate and does not work;

[0017] During cooling operation, in the engine intake / exhaust system, the fresh air at the air intake first exchanges heat with the engine exhaust gas through the sixth heat exchanger to increase its temperature, exchanges heat with the cooling water in the first cooling water system in the third heat exchanger, and dissipates the heat to the first cooling water system. The exhaust gas passes through the fourth heat exchanger. Since the second water pump does not operate, the exhaust gas does not exchange heat with the cooling water in the second cooling water system, and the temperature remains unchanged. The exhaust gas exchanges heat with the low-temperature fresh air in the sixth heat exchanger and is discharged into the air.

[0018] During refrigeration operation, the fan is running, the second water pump in the second cooling water system is not running, and there is no heat input in the second cooling water radiator. Then, after the fresh air exchanges heat with the second cooling water radiator, the temperature does not change; then, the air exchanges heat with the refrigerant first heat exchanger to absorb heat from the high-temperature gaseous refrigerant, and the fresh air temperature rises; then, the air exchanges heat with the first cooling water radiator, because when the first cooling water system is in refrigeration operation, the solenoid valve SV10 is closed, the heat cannot be taken away by the second heat exchanger, the temperature is higher than T1℃, the a1 and c1 channels of the thermostat T1 are opened, and there is heat input in the first cooling water heat dissipation, so the temperature of the air rises again after heat exchange with the first cooling water heat dissipation, and finally, the high-temperature air is discharged from the top of the fan.

[0019] The technical solution adopted by the present invention to solve the technical problem further includes:

[0020] A high-temperature temperature sensor Tp is connected to the compressor output pipeline, a low-temperature temperature sensor Th is connected to the compressor input pipeline, a high-pressure pressure sensor PH is connected to the pipeline between the oil separator and the four-way valve, and a low-pressure pressure sensor PL is connected to the pipeline between the gas-liquid separator and the compressor.

[0021] An air-conditioning water outlet temperature sensor Two is connected to the air-conditioning water outlet end of the first heat exchanger, and an air-conditioning water inlet temperature sensor Twi is connected to the air-conditioning water inlet end of the first heat exchanger.

[0022] A first medium-temperature sensor Th1 is connected to the pipeline between the four-way valve and the gas-liquid separator; a second medium-temperature sensor Th2 is connected to the pipeline between the fifth heat exchanger and the gas-liquid separator.

[0023] A water temperature sensor Tw is connected to the cooling water output end of the first cooling water radiator.

[0024] The output end of the third heat exchanger is connected to a wastewater treatment device to treat and discharge the condensed water in the tail gas.

[0025] The first cooling water radiator, the second cooling water radiator, and the first refrigerant heat exchanger are arranged in such a way that the second cooling water radiator is on the outermost side, the first refrigerant heat exchanger is in the middle, and the first cooling water radiator is on the innermost side, distributed on both sides of the fan.

[0026] The beneficial effects of the present invention are as follows: the present invention utilizes the second cooling water system and the sixth heat exchanger to reuse the remaining 20-30% of the heat in the 70-80°C exhaust gas discharged by the gas engine, thereby reducing heat loss and improving the comprehensive utilization efficiency of energy. The overall heating efficiency of the equipment can be increased from the original 167% to 187%. The present invention utilizes the heat in the exhaust gas recovered by the second cooling water system, which can be absorbed and utilized by the heat pump system through the fifth heat exchanger. While improving the heating capacity and energy efficiency of the equipment, it can also increase the system low pressure, reduce the high / low pressure ratio and exhaust temperature, and will not affect the waste heat recovery in the first cooling water system. The second cooling water radiator in the present invention is arranged at the outermost side, the first refrigerant heat exchanger is in the middle, and the first cooling water radiator is arranged at the innermost side. While utilizing the heat in the exhaust gas recovered by the second cooling water system to effectively increase the waste heat recovery, it can also alleviate the frost rate of the first refrigerant heat exchanger and assist the first refrigerant heat exchanger in defrosting. The present invention utilizes the third heat exchanger, the fourth heat exchanger and the sixth heat exchanger to perform temperature reduction treatment on the engine exhaust gas step by step, so the exhaust gas temperature is basically consistent with the ambient temperature, and no white smoke phenomenon occurs during exhaust.

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the air conditioning heat pump system in the present invention.

[0029] Figure 2 It is a schematic diagram of the engine cooling water / intake and exhaust system in the present invention.

[0030] Figure 3 Schematic diagram of the arrangement of the heat exchanger / radiator in the present invention. DETAILED DESCRIPTION

[0031] This embodiment is a preferred implementation mode of the present invention. Other embodiments whose principles and basic structures are the same or similar to those of this embodiment are within the protection scope of the present invention.

[0032] Please refer to the attached Figure 1 , Attachment Figure 2 and attached Figure 3 The present invention mainly protects an air-conditioning system for improving the utilization of waste heat from a wide temperature range air source heat pump, which includes an air-conditioning heat exchange system, a first cooling water system and a second cooling water system. The first cooling water system is connected to the gas engine cooling system in the air-conditioning heat exchange system, and the second cooling water system is connected to the exhaust end of the gas engine in the air-conditioning heat exchange system.

[0033] In this embodiment, the air conditioning heat exchange system includes a gas engine, a compressor, an oil separator, a four-way valve, a first heat exchanger, a refrigerant heat exchanger and a gas-liquid separator. The compressor is connected to the gas engine, and the compressor is driven by the gas engine. The refrigerant output end of the compressor is connected to the input end of the oil separator, the refrigerant output end of the oil separator is connected to the first heat exchanger through the four-way valve, the output end of the first heat exchanger is connected to the refrigerant heat exchanger, the output end of the refrigerant heat exchanger is connected to the gas-liquid separator through the four-way valve, and the output end of the gas-liquid separator is connected to the input end of the compressor.

[0034] In this embodiment, a high-temperature temperature sensor Tp is connected to the compressor output pipeline, a low-temperature temperature sensor Th is connected to the compressor input pipeline, a high-pressure pressure sensor PH is connected to the pipeline between the oil separator and the four-way valve, and a low-pressure pressure sensor PL is connected to the pipeline between the gas-liquid separator and the compressor.

[0035] In this embodiment, the output end of the first heat exchanger is divided into two paths. The first path is connected to the refrigerant heat exchanger through the electronic expansion valve EXV1, and the second path is connected to the refrigerant input end of the fifth heat exchanger through the electronic expansion valve EXV2. The refrigerant output end of the fifth heat exchanger is connected to the input end of the gas-liquid separator.

[0036] In this embodiment, an air-conditioning water outlet temperature sensor Two is connected to the air-conditioning water outlet end of the first heat exchanger, and an air-conditioning water inlet temperature sensor Twi is connected to the air-conditioning water inlet end of the first heat exchanger.

[0037] In this embodiment, a first medium-temperature sensor Th1 is connected to the pipeline between the four-way valve and the gas-liquid separator; and a second medium-temperature sensor Th2 is connected to the pipeline between the fifth heat exchanger and the gas-liquid separator.

[0038] In this embodiment, the first cooling water system includes a second heat exchanger, a thermostat T1, a thermostat T2, a first water pump, a first filter and a first cooling water radiator. The cooling water output end of the gas engine is connected to the thermostat T1 (i.e., end a1). The output end of the thermostat T1 is divided into two paths, one path (i.e., end c1) is connected to the first cooling water radiator, and the other path (i.e., end b1) is connected to the thermostat T2. The output end of the first cooling water radiator is connected to the first filter. The output end of the thermostat T2 is divided into two paths, one path (i.e., end e1) is connected to the second heat exchanger, the output end of the second heat exchanger is connected to the first filter, and the other path (i.e., end d1) is directly connected to the first filter. The output end of the first filter is connected to the first water pump, and the first water pump is connected to the first cooling water input end of the gas engine through the third heat exchanger or directly connected to the cooling water input end of the gas engine.

[0039] In this embodiment, a water temperature sensor Tw is connected to the cooling water output end of the first cooling water radiator.

[0040] In this embodiment, the second heat exchanger is connected to the air-conditioning water outlet and the air-conditioning water inlet of the first heat exchanger, and a solenoid valve SV10 is connected between the second heat exchanger and the air-conditioning water outlet of the first heat exchanger.

[0041] In this embodiment, the second cooling water system includes a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a sixth heat exchanger, a second filter, a second water pump, a thermostat T3, a three-way valve and a second cooling water radiator. The third heat exchanger is connected to the exhaust gas output end of the gas engine, the first input end of the fourth heat exchanger is connected to the third heat exchanger, and the second input end of the fourth heat exchanger is divided into three paths after passing through the second water pump and the second filter. The first path is directly connected to the second output end of the fourth heat exchanger (i.e., the a3 end) through the thermostat T3 (i.e., the b3 end), the second path is connected to the input end of the fifth heat exchanger, the output end of the fifth heat exchanger is connected to the e3 end of the three-way valve, the third path is connected to the input end of the second cooling water radiator, the output end of the second cooling water radiator is connected to the f3 end of the three-way valve, the d3 section of the three-way valve is connected to the c3 end of the thermostat T3, the first output end of the fourth heat exchanger is connected to the sixth heat exchanger, and the output of the sixth heat exchanger is connected to the exhaust gas input end of the gas engine.

[0042] In this embodiment, the fifth heat exchanger is connected to a refrigerant inlet and outlet.

[0043] In this embodiment, the sixth heat exchanger is connected to an air inlet and an air outlet.

[0044] In this embodiment, a wastewater treatment device is connected to the output end of the third heat exchanger to treat and discharge the condensed water in the tail gas.

[0045] In the first cooling water system, the water pump runs to send medium-temperature cooling water to the engine cavity for heat recovery from the engine cylinder liner and exhaust waste heat, and becomes high-temperature cooling water. Subsequently, it passes through the thermostat T1 for automatic judgment. When the water temperature is lower than T1 (in this embodiment, T1 ranges from 75 to 85°C, and the optimal value is 80°C), the a1 and b1 channels of the thermostat T1 are turned on, and the a1 and c1 channels of the thermostat T1 are closed. When the water temperature is higher than T1 and lower than T1+5°C, the a1 and b1 channels and the a1 and c1 channels of the thermostat T1 are turned on. When the water temperature is higher than T1+5°C, the a1 and c1 channels of the thermostat T1 are turned on, and the a1 and b1 channels of the thermostat T1 are blocked. The a1 and c1 channels of the thermostat T1 are turned on mainly to discharge heat to the air through the radiator to prevent the water temperature from being too high when the heat in the cooling water is not used. After the a1 and b1 channels of the thermostat T1 are turned on, the thermostat T2 makes a judgment. When the water temperature is lower than T2 (in this embodiment, the value range of T2 is 65-75°C, and the optimal value is 71°C), the b1 and d1 channels of the thermostat T2 are turned on, and the b1 and e1 channels of the thermostat T2 are closed. When the water temperature is higher than T2 and lower than T2+5°C, the b1 and d1 channels of the thermostat T2 and the b1 and e1 channels of the thermostat T2 are turned on. When the water temperature is higher than When T2+5℃, the b1 and e1 channels of thermostat T2 are connected, and the b1 and d1 channels of thermostat T2 are blocked. The b1 and d1 channels of thermostat T2 are connected mainly to prevent the cooling water temperature from being too low and affecting the engine operation. The b1 and e1 channels of thermostat T2 are connected to utilize the waste heat generated by the engine to heat the air-conditioning water by exchanging heat with the air-conditioning water in the second heat exchanger; and T1-T2=about 10℃ is required.

[0046] Among them, when the engine exhaust gas is heat exchanged in the third heat exchanger, the fourth heat exchanger and the sixth heat exchanger, condensed water will be generated. This part of condensed water flows into the wastewater treatment device due to gravity, and reacts chemically with related substances in the wastewater treatment device to absorb harmful substances and then discharge them.

[0047] The first cooling water radiator, the second cooling water radiator and the first refrigerant heat exchanger are arranged in such a way that the second cooling water radiator is on the outermost side, the first refrigerant heat exchanger is in the middle and the first cooling water radiator is on the innermost side. These three groups form a module, with a total of two modules, which are distributed on both sides of the fan.

[0048] The present invention also protects a control method for an air conditioning system for improving the utilization of waste heat from a wide temperature range air source heat pump, which includes two modes: heating operation and cooling operation, wherein:

[0049] During heating operation, the gas engine burns natural gas and drives the compressor through a belt. The compressor compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant, and then passes through an oil separator to separate the refrigerant from the lubricating oil. It then passes through a four-way valve to reach the first heat exchanger for heat exchange, heating the air-conditioning circulating water to become a medium-temperature, high-pressure liquid refrigerant. It is then divided into two paths. One path is throttled by the electronic expansion valve EXV1, and then absorbs heat from the air in the outdoor heat exchanger to become a low-temperature, low-pressure gaseous refrigerant. The other path is throttled by the electronic expansion valve EXV2 and then released in the first heat exchanger. The heat in the high-temperature cooling water is absorbed in the five heat exchangers to be converted into a low-temperature, low-pressure gaseous refrigerant. Then, the low-temperature, low-pressure gaseous refrigerants of the two routes are combined and separated from the liquid refrigerant through a gas-liquid separator. The low-temperature, low-pressure gaseous refrigerant returns to the compressor for compression again, and the cycle continues. Among them, the air-conditioning water inlet pipe will be divided into two routes for heating. One route is used for heat exchange with the high-temperature refrigerant in the first heat exchanger, and the other route controls the solenoid valve SV10 to open for heat exchange with the high-temperature cooling water in the second heat exchanger. Finally, the two routes of heated air-conditioning water are combined and sent out from the air-conditioning water outlet pipe.

[0050] During heating operation, in the first cooling water system, the control solenoid valve SV10 is opened, and the heat of the cooling water is taken away by the air-conditioning water in the second heat exchanger. When the cooling water temperature is lower than T1℃ and greater than T2℃, the a1 and b1 channels of thermostat T1 are connected, and the b1 and d1 channels of thermostat T2 and the b1 and e1 channels of thermostat T2 are connected. After the cooling water absorbs the heat of the exhaust gas from the third heat exchanger, it passes through thermostat T1 and thermostat T2 in turn and is divided into two paths. Most of the cooling water is absorbed by the air-conditioning water in the second heat exchanger through the b1 and e1 channels, and a small part is directly bypassed through the b1 and d1 channels. Subsequently, the two cooling waters are mixed and returned to the inlet of the first water pump, and are sent to the third heat exchanger through the first water pump to absorb heat again, and the cycle is repeated.

[0051] During heating operation, in the second cooling water system, the second water pump runs to send cooling water to the fourth heat exchanger for heat exchange, absorbs heat in the 80℃ exhaust gas, and becomes high-temperature cooling water. It is then judged by the thermostat T3. When the water temperature is lower than T3 (in this embodiment, T3 has a value range of 20~30℃, and the optimal value is 25℃), the a3 and b3 channels of the thermostat T3 are turned on, and the a3 and c3 channels are closed. When the water temperature is higher than T3 and less than T3+5℃, the a3 and b3 channels of the thermostat T3 and the a3 and c3 channels are turned on. When the water temperature is higher than T3+5℃, the a3 and c3 channels of the thermostat T3 are turned on, and the a3 and b3 channels of the thermostat T3 are not turned on. Among them, the a3 and b3 channels are turned on, allowing the cooling water to directly return to the inlet of the second water pump and be sent again. The cooling water is heated in the fourth heat exchanger to prevent the cooling water temperature from being too low and maintain the minimum water temperature at around T3°C. After the a3 and c3 channels are turned on, the three-way valve is used to make a judgment. When the ambient temperature T4 is between 0°C±5°C or the unit is in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be turned on, and the cooling water heat is sent to the second cooling water radiator for heat dissipation, which can alleviate the frost on the surface of the refrigerant heat exchanger and assist in defrosting, while improving the heating capacity of the equipment; when the ambient temperature T4 is less than -5°C, or greater than 5°C and the unit is not in the defrosting stage, the three-way valve d3 and e3 channels are controlled to be turned on, and the cooling water heat is sent to the fifth heat exchanger to be absorbed by the low-temperature refrigerant of the heat pump system, which can improve the heating capacity of the heat pump system, increase the system low pressure, and reduce the system pressure ratio.

[0052] During heating operation, in the engine intake / exhaust system, the fresh air at the air intake first passes through the sixth heat exchanger to exchange heat with the engine exhaust gas to increase its temperature, and then is mixed with natural gas in the engine and burned to produce 500~600℃ high-temperature exhaust gas. Then, it exchanges heat with the cooling water in the first cooling water system in the third heat exchanger, and dissipates the heat to the first cooling water system. At this time, the engine exhaust gas temperature becomes about 80℃. Subsequently, the 80℃ exhaust gas passes through the fourth heat exchanger to exchange heat with the cooling water in the second cooling water system, and dissipates the heat to the second cooling water system again. At this time, the engine exhaust gas temperature becomes about 20℃; finally, it exchanges heat with the low-temperature fresh air in the sixth heat exchanger and is discharged into the air.

[0053] During heating operation, the fan runs to suck air from the side and then discharges it from the top. First, when the ambient temperature T4 is between 0℃±5℃ or the unit is in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be connected, and the cooling water heat is sent to the second cooling water radiator to exchange heat with the fresh air, and the fresh air temperature rises; when the ambient temperature T4 is less than -5℃, or greater than 5℃, and it is not in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be closed, and there is no heat input in the second cooling water radiator. Then, after the fresh air exchanges heat with the second cooling water radiator, the temperature does not change. ; Then, the air exchanges heat with the first heat exchanger of the refrigerant, and the heat is absorbed by the low-temperature gaseous refrigerant, and the temperature of the fresh air decreases; subsequently, the air exchanges heat with the first cooling water radiator. Because the solenoid valve SV10 is opened when the first cooling water system is in heating operation, the heat is taken away by the second heat exchanger. When the temperature is lower than T1°C (in this embodiment, T1 has a value range of 75~85°C, and the optimal value is 80°C), the a1 and c1 channels of the thermostat T1 are closed, and there is no heat input in the first cooling water heat dissipation. Therefore, the temperature of the air does not change after the heat exchange with the first cooling water heat dissipation. Finally, the low-temperature air is discharged from the top of the fan.

[0054] During refrigeration operation, the gas engine burns natural gas to drive the compressor through a belt. The compressor compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The refrigerant is separated from the lubricating oil by an oil separator, and then passes through a four-way valve to the first refrigerant heat exchanger to exchange heat with the air. The high-temperature, high-pressure gaseous refrigerant absorbs heat from the air and becomes a medium-temperature, high-pressure liquid refrigerant. After being throttled by the electronic expansion valve EXV1, it absorbs heat from the air-conditioning water in the first heat exchanger and becomes a low-temperature, low-pressure gaseous refrigerant. The other electronic expansion valve EXV2 is closed, and the fifth heat exchanger does not work. Then, the low-temperature, low-pressure gaseous refrigerant coming out of the first heat exchanger passes through the four-way valve to separate the gaseous refrigerant from the liquid refrigerant in the gas-liquid separator, and the low-temperature, low-pressure gaseous refrigerant returns to the compressor to be compressed again, and the cycle continues. Among them, the temperature of the air-conditioning inlet water is reduced after heat exchange with the low-temperature refrigerant in the first heat exchanger, and the other control solenoid valve SV10 is closed, then the second heat exchanger does not work. Finally, the cooled air-conditioning water is sent out from the air-conditioning outlet pipe.

[0055] During refrigeration operation, in the first cooling water system, the control solenoid valve SV10 is closed, and the heat of the cooling water is not taken away by the air-conditioning water in the second heat exchanger. When the cooling water temperature is higher than T1℃, the a1 and b1 channels and a1 and c1 channels of the thermostat T1 are turned on, and the b1 and e1 channels of the thermostat T2 are turned on. After the cooling water absorbs the exhaust heat from the third heat exchanger, it passes through the thermostat T1 in sequence and is divided into two paths. One part passes through the a1 and c1 channels of the thermostat T1 and takes away the heat through the air in the first cooling water heat dissipation, and the cooling water temperature is lowered. The other part passes through the a1 and b1 channels of the thermostat T1 and the b1 and e1 channels of the thermostat T2 and passes through the second heat exchanger without heat exchange, and the temperature remains unchanged. Subsequently, the two cooling waters are mixed and returned to the inlet of the first water pump, and are sent to the third heat exchanger again through the first water pump to absorb heat, and the cycle is repeated.

[0056] During refrigeration operation, in the second cooling water system, the second water pump does not run, and there is no heat exchange in the fourth heat exchanger for the 80°C exhaust gas, so the exhaust gas temperature remains basically unchanged. Therefore, the second cooling water does not dissipate heat and there is no heat exchange in the fifth heat exchanger. Therefore, the second cooling water system is not put into operation and does not work.

[0057] During refrigeration operation, in the engine intake / exhaust system, the fresh air at the air intake first passes through the sixth heat exchanger to exchange heat with the engine exhaust gas to increase its temperature, and then is mixed with natural gas in the engine and burned to produce 500~600℃ high-temperature exhaust gas. Then, it exchanges heat with the cooling water in the first cooling water system in the third heat exchanger to dissipate the heat to the first cooling water system. At this time, the engine exhaust gas temperature becomes about 80℃. Subsequently, the 80℃ exhaust gas passes through the fourth heat exchanger. Since the second water pump is not running, the 80℃ exhaust gas does not exchange heat with the cooling water in the second cooling water system, and the temperature remains unchanged. Finally, it is discharged into the air after exchanging heat with the low-temperature fresh air in the sixth heat exchanger.

[0058] During refrigeration operation, the fan operates to suck air from the side and then discharge it from the top. First, the second water pump in the second cooling water system does not operate, so there is no heat input in the second cooling water radiator, and the temperature of the fresh air does not change after heat exchange with the second cooling water radiator; then, the air exchanges heat with the first heat exchanger of the refrigerant to absorb heat from the high-temperature gaseous refrigerant, and the temperature of the fresh air rises; then, the air exchanges heat with the first cooling water radiator, because when the first cooling water system is in refrigeration operation, the solenoid valve SV10 is closed, and the heat cannot be taken away by the second heat exchanger, and the temperature is higher than T1℃ (in this embodiment, T1 ranges from 75 to 85℃, and the optimal value is 80℃). At this time, the a1 and c1 channels of the thermostat T1 are opened, and heat is input in the first cooling water heat dissipation, so the temperature of the air rises again after heat exchange with the first cooling water heat dissipation, and finally, the high-temperature air is discharged from the top of the fan.

[0059] In this embodiment, the control method of the electronic expansion valve EXV1 includes: during cooling / heating operation, the electronic expansion valve EXV1 is opened, the suction temperature Th1 and the evaporation temperature Te corresponding to the low pressure PL are detected, and the opening of the electronic expansion valve EXV1 is adjusted to control the suction superheat Tssh1 (Tssh1=Th1-Te) to the target suction superheat SH1.

[0060] In this embodiment, the electronic expansion valve EXV2 is controlled in the following manner: during heating operation, when the ambient temperature T4 is at 0°C ± 5°C or the unit is in the defrosting stage, the suction temperature Th2 and the evaporation temperature Te corresponding to the low pressure PL are detected, and the opening of the electronic expansion valve EXV2 is adjusted to control the suction superheat Tssh2 (Tssh2 = Th2 - Te) to be the target suction superheat SH2; when the ambient temperature T4 is less than -5°C, or greater than 5°C, and is not in the defrosting stage, the electronic expansion valve EXV2 is closed to 0P, and the fifth heat exchanger does not participate in the operation; during cooling operation, the electronic expansion valve EXV2 is closed to 0P, and the fifth heat exchanger does not participate in the operation.

[0061] The present invention utilizes the second cooling water system and the sixth heat exchanger to reuse the remaining 20-30% of the heat in the 70-80°C exhaust gas discharged by the gas engine, thereby reducing heat loss and improving the comprehensive utilization efficiency of energy. The overall heating efficiency of the equipment can be increased from the original 167% to 187%. The present invention utilizes the heat in the exhaust gas recovered by the second cooling water system, which can be absorbed and utilized by the heat pump system through the fifth heat exchanger. While improving the heating capacity and energy efficiency of the equipment, it can also increase the system low pressure, reduce the high / low pressure ratio and exhaust temperature, and will not affect the waste heat recovery in the first cooling water system. The second cooling water radiator in the present invention is arranged at the outermost side, the first refrigerant heat exchanger is in the middle, and the first cooling water radiator is arranged at the innermost side. While utilizing the heat in the exhaust gas recovered by the second cooling water system to effectively increase the waste heat recovery, it can also alleviate the frost rate of the first refrigerant heat exchanger and assist the first refrigerant heat exchanger in defrosting. The present invention utilizes the third heat exchanger, the fourth heat exchanger and the sixth heat exchanger to perform temperature reduction treatment on the engine exhaust gas step by step, so the exhaust gas temperature is basically consistent with the ambient temperature, and no white smoke phenomenon occurs during exhaust.

Claims

1. An air conditioning system for improving the utilization of waste heat from a wide temperature range air source heat pump, characterized by: The system comprises an air conditioning heat exchange system, a first cooling water system and a second cooling water system, wherein the first cooling water system is connected to the gas engine cooling system in the air conditioning heat exchange system, and the second cooling water system is connected to the gas engine exhaust end in the air conditioning heat exchange system, wherein: The air conditioning heat exchange system includes a gas engine, a compressor, an oil separator, a four-way valve, a first heat exchanger, a refrigerant heat exchanger and a gas-liquid separator. The compressor is connected to the gas engine, the refrigerant output end of the compressor is connected to the input end of the oil separator, the refrigerant output end of the oil separator is connected to the first heat exchanger through the four-way valve, the output end of the first heat exchanger is connected to the refrigerant heat exchanger, the output end of the refrigerant heat exchanger is connected to the gas-liquid separator through the four-way valve, the output end of the gas-liquid separator is connected to the input end of the compressor, the output end of the first heat exchanger is divided into two paths, the first path is connected to the refrigerant heat exchanger through the electronic expansion valve EXV1, the second path is connected to the refrigerant input end of the fifth heat exchanger through the electronic expansion valve EXV2, and the refrigerant output end of the fifth heat exchanger is connected to the gas-liquid separator input end; The first cooling water system includes a second heat exchanger, a thermostat T1, a thermostat T2, a first water pump, a first filter and a first cooling water radiator. The cooling water output end of the gas engine is connected to the a1 end of the thermostat T1. The output end of the thermostat T1 is divided into two paths, one path of the c1 end is connected to the first cooling water radiator, and one path of the b1 end is connected to the thermostat T2. The output end of the first cooling water radiator is connected to the first filter. The output end of the thermostat T2 is divided into two paths, one path of the e1 end is connected to the second heat exchanger, the output end of the second heat exchanger is connected to the first filter, and one path of the d1 end is directly connected to the first filter. The output end of the first filter is connected to the first water pump. The first water pump is connected to the first cooling water input end of the gas engine through the third heat exchanger. The second heat exchanger is connected to the air-conditioning water outlet and the air-conditioning water inlet of the first heat exchanger. A solenoid valve SV10 is connected between the second heat exchanger and the air-conditioning water outlet of the first heat exchanger. The second cooling water system includes a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a sixth heat exchanger, a second filter, a second water pump, a thermostat T3, a three-way valve and a second cooling water radiator. The third heat exchanger is connected to the exhaust gas output end of the gas engine, the first input end of the fourth heat exchanger is connected to the third heat exchanger, the second input end of the fourth heat exchanger is divided into three paths after passing through the second water pump and the second filter, the first path is connected to the b3 end of the thermostat T3, the a3 end of the thermostat T3 is connected to the second output end of the fourth heat exchanger, the second path is connected to the input end of the fifth heat exchanger, the output end of the fifth heat exchanger is connected to the e3 end of the three-way valve, the third path is connected to the input end of the second cooling water radiator, the output end of the second cooling water radiator is connected to the f3 end of the three-way valve, the d3 section of the three-way valve is connected to the c3 end of the thermostat T3, the first output end of the fourth heat exchanger is connected to the sixth heat exchanger, and the output of the sixth heat exchanger is connected to the exhaust gas input end of the gas engine.

2. The air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump according to claim 1, characterized in that: A high-temperature temperature sensor Tp is connected to the compressor output pipeline, a low-temperature temperature sensor Th is connected to the compressor input pipeline, a high-pressure pressure sensor PH is connected to the pipeline between the oil separator and the four-way valve, and a low-pressure pressure sensor PL is connected to the pipeline between the gas-liquid separator and the compressor.

3. The air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump according to claim 1, characterized in that: An air-conditioning water outlet temperature sensor Two is connected to the air-conditioning water outlet end of the first heat exchanger, and an air-conditioning water inlet temperature sensor Twi is connected to the air-conditioning water inlet end of the first heat exchanger.

4. The air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump according to claim 1, characterized in that: A first medium-temperature sensor Th1 is connected to the pipeline between the four-way valve and the gas-liquid separator; a second medium-temperature sensor Th2 is connected to the pipeline between the fifth heat exchanger and the gas-liquid separator.

5. The air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump according to claim 1, characterized in that: A water temperature sensor Tw is connected to the cooling water output end of the first cooling water radiator.

6. The air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump according to claim 1, characterized in that: The output end of the third heat exchanger is connected to a wastewater treatment device to treat and discharge the condensed water in the tail gas.

7. The air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump according to claim 1, characterized in that: The first cooling water radiator, the second cooling water radiator, and the first refrigerant heat exchanger are arranged in such a way that the second cooling water radiator is on the outermost side, the first refrigerant heat exchanger is in the middle, and the first cooling water radiator is on the innermost side, distributed on both sides of the fan.

8. A control method for an air conditioning system for improving the utilization of waste heat from a wide temperature range air source heat pump using the air conditioning system for improving the utilization of waste heat from a wide temperature range air source heat pump as claimed in claim 7, characterized in that: The control method includes two modes: heating operation and cooling operation, wherein: During heating operation, the gas engine burns natural gas to drive the compressor to operate. The compressor compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant, and then passes through the oil separator to separate the refrigerant and the lubricating oil. Then, it passes through the four-way valve to reach the first heat exchanger for heat exchange, heating the air-conditioning circulating water to become a medium-temperature, high-pressure liquid refrigerant. Then, it is divided into two paths. One path is throttled by the electronic expansion valve EXV1, and then absorbs heat from the air in the outdoor heat exchanger to become a low-temperature, low-pressure gaseous refrigerant. The other path is throttled by the electronic expansion valve EXV2 and then enters the fifth The heat exchanger absorbs the heat from the high-temperature cooling water and turns it into a low-temperature, low-pressure gaseous refrigerant. Then, the low-temperature, low-pressure gaseous refrigerants of the two routes merge and pass through a gas-liquid separator to separate the gaseous refrigerant from the liquid refrigerant. The low-temperature, low-pressure gaseous refrigerant returns to the compressor for compression again. In this cycle, the air-conditioning water inlet pipe will be divided into two routes for heating. One route exchanges heat with the high-temperature refrigerant in the first heat exchanger, and the other route controls the solenoid valve SV10 to open and exchanges heat with the high-temperature cooling water in the second heat exchanger. Finally, the two routes of heated air-conditioning water merge and are sent out from the air-conditioning water outlet pipe. During heating operation, in the first cooling water system, the control solenoid valve SV10 is opened, and the heat of the cooling water is taken away by the air-conditioning water in the second heat exchanger. When the cooling water temperature is lower than T1°C and greater than T2°C, the a1 and b1 channels of the thermostat T1 are turned on, and the b1 and d1 channels of the thermostat T2 and the b1 and e1 channels of the thermostat T2 are turned on. After the cooling water absorbs the heat of the exhaust gas from the third heat exchanger, it passes through the thermostat T1 and the thermostat T2 in sequence and is divided into two paths. One part is absorbed by the air-conditioning water in the second heat exchanger through the b1 and e1 channels, and the other part is directly bypassed through the b1 and d1 channels. The two cooling waters are mixed and returned to the inlet of the first water pump, and are sent to the third heat exchanger to absorb heat again through the first water pump, and the cycle is repeated. During heating operation, in the second cooling water system, the second water pump runs to send cooling water to the fourth heat exchanger for heat exchange, absorbs heat in the exhaust gas, and becomes high-temperature cooling water. It is then judged by the thermostat T3. When the water temperature is lower than T3, the a3 and b3 channels of the thermostat T3 are turned on, and the a3 and c3 channels are closed. When the water temperature is higher than T3 and lower than T3+5℃, the a3 and b3 channels and the a3 and c3 channels of the thermostat T3 are turned on. When the water temperature is higher than T3+5℃, the a3 and c3 channels of the thermostat T3 are turned on, and the a3 and b3 channels of the thermostat T3 are not turned on. Among them, the a3 and b3 channels are turned on. The cooling water is directly returned to the inlet of the second water pump and sent to the fourth heat exchanger for heating again to maintain the minimum water temperature at about T3℃. After the a3 and c3 channels are connected, the three-way valve is used for judgment. When the ambient temperature T4 is between 0℃±5℃ or the unit is in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be connected to send the cooling water heat to the second cooling water radiator for heat dissipation. When the ambient temperature T4 is less than -5℃, or greater than 5℃ and the unit is not in the defrosting stage, the three-way valve d3 and e3 channels are controlled to be connected to send the cooling water heat to the fifth heat exchanger to be absorbed by the low-temperature refrigerant of the heat pump system. During heating operation, in the engine intake / exhaust system, the fresh air at the air intake first exchanges heat with the engine exhaust gas through the sixth heat exchanger to increase its temperature, exchanges heat with the cooling water in the first cooling water system in the third heat exchanger, and dissipates the heat to the first cooling water system. The exhaust gas exchanges heat with the cooling water in the second cooling water system through the fourth heat exchanger, and dissipates the heat to the second cooling water system again. It exchanges heat with the low-temperature fresh air in the sixth heat exchanger and is discharged into the air. During heating operation, when the ambient temperature T4 is between 0℃±5℃ or the unit is in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be connected, and the cooling water heat is sent to the second cooling water radiator for heat exchange with fresh air, and the air temperature rises; when the ambient temperature T4 is less than -5℃, or greater than 5℃, and is not in the defrosting stage, the three-way valve d3 and f3 channels are controlled to be closed, and the air temperature remains unchanged after the fresh air exchanges heat with the second cooling water radiator, and then the air exchanges heat with the first heat exchanger of the refrigerant and the heat is absorbed by the low-temperature gaseous refrigerant, and the fresh air temperature decreases; finally, after the air exchanges heat with the first cooling water radiator, the fresh air temperature remains unchanged, because the solenoid valve SV10 is opened, and the heat is taken away by the second heat exchanger. When the temperature is lower than T1℃, the a1 and c1 channels of the thermostat T1 are closed, so there is no heat input to the first cooling water radiator; During refrigeration operation, the gas engine burns natural gas to drive the compressor to run. The compressor compresses the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant. The refrigerant passes through the oil separator to separate the refrigerant from the lubricating oil. The refrigerant then passes through the four-way valve to the first refrigerant heat exchanger to exchange heat with the air. The high-temperature, high-pressure gaseous refrigerant absorbs heat from the air and becomes a medium-temperature, high-pressure liquid refrigerant. After being throttled by the electronic expansion valve EXV1, the refrigerant absorbs heat from the air-conditioning water in the first heat exchanger and becomes a low-temperature, low-pressure gaseous refrigerant. , the other electronic expansion valve EXV2 is closed, the fifth heat exchanger does not work, then, the low-temperature, low-pressure gaseous refrigerant coming out of the first heat exchanger passes through the four-way valve to separate the gaseous refrigerant from the liquid refrigerant in the gas-liquid separator, and the low-temperature, low-pressure gaseous refrigerant returns to the compressor for compression again, and the cycle continues; the air-conditioning inlet water is cooled after heat exchange with the low-temperature refrigerant in the first heat exchanger, and the other control solenoid valve SV10 is closed, then the second heat exchanger does not work, and the cooled air-conditioning water is sent out from the air-conditioning outlet pipe; During refrigeration operation, in the first cooling water system, the solenoid valve SV10 is controlled to be closed. When the cooling water temperature is higher than T1°C, the a1 and b1 channels and a1 and c1 channels of the thermostat T1 are turned on, and the b1 and e1 channels of the thermostat T2 are turned on. After the cooling water absorbs the exhaust heat from the third heat exchanger, it is divided into two paths after passing through the thermostat T1. One part passes through the a1 and c1 channels of the thermostat T1 and is taken away by the air in the first cooling water heat dissipation to reduce the cooling water temperature. The other part passes through the a1 and b1 channels of the thermostat T1 and the b1 and e1 channels of the thermostat T2 and passes through the second heat exchanger without heat exchange. The two cooling waters are mixed and returned to the inlet of the first water pump, and are sent to the third heat exchanger again through the first water pump to absorb heat, and the cycle is repeated. During refrigeration operation, in the second cooling water system, the second water pump does not operate, the exhaust gas does not exchange heat in the fourth heat exchanger, and the second cooling water system does not operate and does not work; During cooling operation, in the engine intake / exhaust system, the fresh air at the air intake first exchanges heat with the engine exhaust gas through the sixth heat exchanger to increase its temperature, exchanges heat with the cooling water in the first cooling water system in the third heat exchanger, and dissipates the heat to the first cooling water system. The exhaust gas passes through the fourth heat exchanger. Since the second water pump does not operate, the exhaust gas does not exchange heat with the cooling water in the second cooling water system, and the temperature remains unchanged. The exhaust gas exchanges heat with the low-temperature fresh air in the sixth heat exchanger and is discharged into the air. During refrigeration operation, the fan is running, the second water pump in the second cooling water system is not running, and there is no heat input in the second cooling water radiator. Then, after the fresh air exchanges heat with the second cooling water radiator, the temperature does not change; then, the air exchanges heat with the refrigerant first heat exchanger to absorb heat from the high-temperature gaseous refrigerant, and the fresh air temperature rises; then, the air exchanges heat with the first cooling water radiator, because when the first cooling water system is in refrigeration operation, the solenoid valve SV10 is closed, the heat cannot be taken away by the second heat exchanger, the temperature is higher than T1℃, the a1 and c1 channels of the thermostat T1 are opened, and there is heat input in the first cooling water heat dissipation, so the temperature of the air rises again after heat exchange with the first cooling water heat dissipation, and finally, the high-temperature air is discharged from the top of the fan.

9. The control method for an air conditioning system for improving the utilization of waste heat of a wide temperature range air source heat pump according to claim 8, characterized in that: The control method of the electronic expansion valve EXV1 includes: during cooling / heating operation, the electronic expansion valve EXV1 is opened, the suction temperature Th1 and the evaporation temperature Te corresponding to the low pressure PL are detected, and the opening of the electronic expansion valve EXV1 is adjusted to control the suction superheat Tssh1=Th1-Te to be the target suction superheat SH1; Control mode of electronic expansion valve EXV2: During heating operation, when the ambient temperature T4 is at 0℃±5℃ or the unit is in the defrosting stage, the suction temperature Th2 and the evaporation temperature Te corresponding to the low pressure PL are detected, and the opening of the electronic expansion valve EXV2 is adjusted to control the suction superheat Tssh2=Th2-Te as the target suction superheat SH2; when the ambient temperature T4 is less than -5℃, or greater than 5℃, and is not in the defrosting stage, the electronic expansion valve EXV2 is closed to 0P, and the fifth heat exchanger does not participate in the work; when the cooling operation is carried out, the electronic expansion valve EXV2 is closed to 0P, and the fifth heat exchanger does not participate in the work.

Images