Wide-temperature-range air source heat pump waste heat efficient utilization system and control method thereof

Abstract

The invention discloses an efficient waste heat utilization system of a wide-temperature-range air source heat pump and a control method of the efficient waste heat utilization system, relates to the technical field of air source heat pump systems, and solves the technical problem that an existing heat pump does not effectively utilize heat generated during working of an engine and causes resource waste. The low-temperature absorption type refrigeration module is used for absorbing waste heat of the engine for refrigeration; the hot water heat exchange system comprises a cylinder sleeve water heat exchanger, a tail gas heat energy heat exchanger PHE5, a domestic hot water heat exchanger PHE3, a heating water heat exchanger PHE2, a radiator and an engine cooling water pump. Multi-mode efficient operation is realized; the multi-combined supply operation of the heat pump system is realized; the trend of engine waste heat is automatically adjusted and controlled, so that efficient operation of a heat pump system is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of air source heat pump systems, and in particular to a control method for heat energy recovery and reuse in air source heat pump systems. Background Art

[0002] Heat pump technology has been widely used in various fields of life and production. Heat pump products such as heat pump air conditioners, heat pump water heaters, heat pump dryers, and automotive heat pumps meet diverse user needs. The operating principle of heat pump air conditioners is based on the reverse Carnot cycle in thermodynamics. The heating process begins in the evaporator, where a low-temperature liquid refrigerant absorbs heat from the surrounding environment and evaporates into a gas. During this process, heat from the external heat source is extracted and transferred to the refrigerant. The gaseous refrigerant enters the compressor, where its pressure and temperature are significantly increased. Mechanical energy is used to compress the refrigerant, raising its temperature and turning it into a high-temperature, high-pressure gas. This high-temperature, high-pressure gas is then transported to the condenser, where it releases heat, which can be used for indoor heating or hot water supply. As the refrigerant cools, it condenses and transforms into a liquid. It then enters the expansion valve, which controls the refrigerant's flow and rapidly reduces its pressure. This decrease in pressure also lowers the temperature of the liquid refrigerant, preparing it for the next round of heat extraction in the evaporator. The cooling process is the opposite, absorbing heat from the room and dissipating it outdoors.

[0003] In addition to electricity, heat pumps can also be driven by fuel-burning engines. Currently, most heat pump air conditioners on the market can only meet the needs of cooling or heating simultaneously. To use hot water, additional hot water equipment such as boilers, electric water heaters, or heat pump water heaters is required. Even though a small number of heat pump air conditioners can produce a small amount of hot water while cooling or heating, they are limited in production due to low hot water output, high energy consumption, and poor reliability. Furthermore, due to the influence of the refrigerant medium and outdoor temperature, hot water production at ultra-low temperatures consumes high energy and reaches low temperatures, making it difficult to meet daily usage requirements.

[0004] A wide-temperature-range air-source heat pump is a system that uses an engine to drive a compressor to achieve a cooling / heating cycle. The mechanical efficiency of the engine-driven compressor is only around 35%, with the remaining 65% of the energy being stored as heat. By recovering waste heat, this energy can be used to produce hot water, with temperatures reaching up to 80°C. While existing heat pumps can simultaneously generate domestic hot water while providing cooling / heating, there are no wide-temperature-range air-source heat pumps that effectively utilize engine waste heat to provide cooling, heating, ultra-low-temperature heating, and domestic hot water. Furthermore, when only cooling is required, the engine's waste heat is dissipated into the air to maintain the engine's operating temperature within a reasonable range. This waste heat contributes nothing to cooling and is wasted. The mechanical efficiency of the engine-driven compressor is only around 35%, with the remaining 65% being stored as heat. Current heat pumps fail to effectively utilize this heat, particularly during cooling operations, resulting in a waste of resources.

[0005] The low-temperature absorption refrigeration module is the primary component of an absorption chiller. This system utilizes the absorption / desorption properties of different substances for the refrigerant, replacing the compressor used in traditional compression refrigeration to achieve heat transfer. The main components include a generator, condenser, evaporator, and absorber. Refrigerants are typically volatile substances with high latent heat of vaporization, such as ammonia or water. The refrigerant is responsible for transferring heat during the cycle. The absorbent is a substance that strongly absorbs the refrigerant and has a significant difference in boiling point from the refrigerant, facilitating separation. Taking the "lithium bromide-water" absorption chiller as an example, water is the refrigerant and lithium bromide solution is the absorbent. The lithium bromide solution with a low concentration enters the generator and is heated by an external heat source. The high-temperature and high-pressure water vapor generated in the generator enters the condenser, exchanges heat with the cooling water, releases heat, and cools and liquefies to become high-pressure liquid water; the high-pressure liquid water is reduced in pressure by the throttle valve and enters the evaporator. Under the low-pressure environment, the liquid water quickly evaporates into water vapor. The evaporation process absorbs heat from the surrounding medium, lowering the temperature of the chilled water. Finally, the cold is sent into the room through the fan to achieve refrigeration; the dilute solution is pressurized by the solution pump and then sent back to the generator to complete the entire cycle. Summary of the Invention

[0006] In summary, in order to solve the technical problem that the existing heat pump does not effectively utilize the heat generated by the engine, resulting in waste of resources, a wide temperature range air source heat pump waste heat efficient utilization system and its control method are proposed.

[0007] In order to solve the technical deficiencies proposed by the present invention, the technical solutions adopted are: A wide-temperature-range air-source heat pump waste heat efficient utilization system includes a heat pump device for cooling or heating and an engine for driving the heat pump device. The system is characterized in that: the wide-temperature-range air-source heat pump waste heat efficient utilization system also includes a low-temperature absorption refrigeration module for absorbing engine waste heat for cooling, a hot water heat exchange system for heat exchange using system heat, and a control system for controlling the operation of the heat pump device, the low-temperature absorption refrigeration module, the engine, and the hot water heat exchange system; The hot water heat exchange system includes a cylinder water heat exchanger arranged outside the engine cylinder liner, an exhaust gas heat energy heat exchanger PHE5 arranged on the engine exhaust pipe, a domestic hot water heat exchanger PHE3 for providing heat exchange for domestic water, a heating water heat exchanger PHE2 for heat exchange of heating water, a radiator for providing heat dissipation for the engine circulating water, and an engine cooling water pump for driving the engine cooling water to circulate through the radiator, or through the domestic hot water heat exchanger PHE3, or through the heating water heat exchanger PHE2 and the low-temperature absorption refrigeration module.

[0008] The technical features that further define the present invention include: The hot water heat exchange system also includes a first thermostat, a second thermostat, a third solenoid valve, a second solenoid valve, a fifth solenoid valve and a sixth solenoid valve; wherein, the first thermostat is arranged between the cylinder jacket water heat exchanger and the radiator, and when the engine cooling water is greater than a preset value M, the engine cooling water is opened to circulate through the radiator; the second thermostat is arranged at the inlet connected to the first thermostat, one of the outlets is directly connected to the cylinder jacket water heat exchanger through the engine cooling water pump and the exhaust gas heat energy heat exchanger PHE5, and the other outlet is connected to the domestic hot water heat exchanger PHE3 and the heating water heat exchanger PHE2; when the engine cooling water is lower than the preset value N, the cylinder jacket water heat exchanger output The engine cooling water is driven by the engine cooling water pump and directly returns to the exhaust gas heat energy exchanger PHE5 through the first thermostat and the second thermostat without heat recovery; when the engine cooling water is higher than the preset value N, the engine cooling water entering from the second thermostat inlet is subjected to heat energy recovery in the domestic hot water heat exchanger PHE3, the heating water heat exchanger PHE2 or the low-temperature absorption refrigeration module; the third solenoid valve controls the waste heat inlet of the domestic hot water heat exchanger PHE3; the second solenoid valve controls the water inlet of the heating water heat exchanger PHE2; the fifth solenoid valve and the sixth solenoid valve are connected to control the low-temperature absorption refrigeration module to access or exit the engine cooling water circulation pipeline.

[0009] The hot water heat exchange system also includes a refrigerant heat exchanger PHE4 connected in parallel with the domestic hot water heat exchanger PHE3 and the heating water heat exchanger PHE2 for heat exchange with the refrigerant of the heat pump device. A fourth solenoid valve SV4 is provided at the inlet of the refrigerant heat exchanger PHE4.

[0010] The control method of the wide temperature range air source heat pump waste heat efficient utilization system includes control methods under four control modes: cooling, cooling + domestic hot water, heating, and heating + domestic hot water; wherein: (1) The cooling mode control method is: Select "Cooling" in the control system interface mode, turn off the domestic hot water function switch, and click "Start". The second solenoid valve SV2, the third solenoid valve SV3, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 are closed, and the sixth solenoid valve SV6 is opened. The low-temperature absorption refrigeration module is connected to the engine cooling water circulation pipeline. After that, the engine is started and the heat pump device enters normal cooling mode and starts running. When the engine starts and runs until the cooling water temperature Tliq ≥ 71°C for 60 seconds, the fifth solenoid valve SV5 opens. After 5 seconds, the sixth solenoid valve SV6 closes. After the fifth solenoid valve SV5 opens for 10 seconds, the low-temperature absorption refrigeration module starts running. During the operation, the output load is normally adjusted according to the following control: (1) 71℃≤Tliq<75℃, low-temperature absorption refrigeration module output load 50%; (2) 75℃≤Tliq<80℃, the output load of the low-temperature absorption refrigeration module is 75%; (3) Tliq ≥ 80℃, low-temperature absorption refrigeration module output load 100%; (4) Tliq < 71°C for 120 seconds, low-temperature absorption refrigeration module output load 0%; When the system is in standby mode or shut down, the heat pump unit shuts down in normal cooling mode, and after the engine stops, the low-temperature absorption refrigeration module shuts down again; (2) The control method of cooling + hot water mode is: Select "Cooling" in the control system interface mode, turn on the domestic hot water function switch, and after clicking the "Start" operation, the second solenoid valve SV2, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 are closed, the third solenoid valve SV3 and the sixth solenoid valve SV6 are opened, and the heat pump device starts to operate in normal cooling mode. When the engine starts and runs to the cooling water temperature Tliq ≥ 75°C for 60 seconds, the fifth solenoid valve SV5 is opened, and after 5 seconds, the sixth solenoid valve SV6 is closed. The low-temperature absorption refrigeration module is connected to the engine cooling water circulation pipeline. After the fifth solenoid valve SV5 is opened for 10 seconds, the low-temperature absorption refrigeration module starts to operate, and the output load adjustment is performed according to the same output load adjustment conditions as the cooling mode control method; During operation, the third solenoid valve SV3 performs control according to the domestic hot water inlet temperature Thwi and the set temperature Ths, and the set temperature Ths is set to a maximum of 70°C; When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; When the third solenoid valve SV3 is closed and Thwi is less than Ths-5°C for 60 seconds, the third solenoid valve SV3 opens. When the third solenoid valve SV3 is in the open state, if Ths-5℃≤Thwi<Ths+2℃ for 30 minutes, the output load of the low-temperature absorption refrigeration module is adjusted to 0% until the third solenoid valve SV3 is closed, and the output load of the low-temperature absorption refrigeration module returns to normal regulation; When the system is in standby or shutdown mode, the heat pump unit is shut down in normal cooling mode, and the low-temperature absorption cooling module is turned off 60 seconds after the engine stops; (3) The heating mode control method is: Select "Heating" in the control system interface mode, turn off the domestic hot water function switch, and click "Start" to run the program according to the ambient temperature: (a) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be ≥ -10°C, the third solenoid valve SV3, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 are closed, the second solenoid valve SV2 and the sixth solenoid valve SV6 are opened, and the heat pump unit starts to operate in normal heating mode. The low-temperature absorption cooling module remains closed; the cooling water flows through the heating water heat exchanger PHE2 to heat the heating water; (b) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be less than -10°C, the third solenoid valve SV3 and the fifth solenoid valve SV5 are closed, the second solenoid valve SV2 and the sixth solenoid valve SV6 are opened, and the heat pump device starts to operate in normal heating mode. The low-temperature absorption refrigeration module remains closed; the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the fourth solenoid valve SV4 is opened, and the cooling water flows through the refrigerant heat exchanger PHE4 to exchange heat with the refrigerant of the heat pump; (4) The control method of heating + hot water mode is: Select "Heating" in the control system interface mode, turn on the domestic hot water function switch, and click "Start" to run the program according to the ambient temperature: (a) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be ≥ -10°C, the fourth solenoid valve SV4 and the fifth solenoid valve SV5 are closed, the second solenoid valve SV2, the third solenoid valve SV3, and the sixth solenoid valve SV6 are opened, and the heat pump device starts to operate in normal heating mode. The low-temperature absorption cooling module remains closed. During operation, the third solenoid valve SV3 is controlled according to the domestic hot water inlet temperature Thwi and the set temperature Ths, with Ths being set at a maximum of 60°C; When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; After the third solenoid valve SV3 is closed, when Thwi < Ths - 5°C for 60 seconds, the third solenoid valve SV3 opens; the engine cooling water does not exchange heat with the refrigerant, nor does it enter the low-temperature absorption refrigeration module. The second solenoid valve SV2 opens, and the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the third solenoid valve SV3 opens, and the cooling water flows through the domestic hot water heat exchanger PHE3 to exchange heat with the domestic hot water to heat the hot water; (b) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be less than -10°C, the fifth solenoid valve SV5 closes, the second solenoid valve SV2, the third solenoid valve SV3, the fourth solenoid valve SV4, and the sixth solenoid valve SV6 open, the heat pump device starts operating in normal heating mode, and the low-temperature absorption cooling module remains closed; During operation, the third solenoid valve SV3 is controlled according to the domestic hot water inlet temperature Thwi and the set temperature Ths, with Ths set to a maximum of 50°C: When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; After the third solenoid valve SV3 is closed, when Thwi<Ths-5℃ continues for 60s, the third solenoid valve SV3 opens; the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the cooling water flows through the domestic hot water heat exchanger PHE3 to exchange heat with the domestic hot water to heat the hot water; the cooling water flows through PHE4 to exchange heat with the refrigerant of the heat pump.

[0011] In heating + hot water mode, the maximum set temperature allowed for domestic hot water is 50°C.

[0012] The beneficial effects of the present invention are as follows: the present invention realizes efficient operation of a wide-temperature range air source heat pump in multiple modes of refrigeration, heating, refrigeration + hot water, and heating + hot water by rationally allocating and utilizing the engine waste heat; the present invention recovers and utilizes the engine waste heat in multiple stages, and sets a plurality of waste heat recovery devices and low-temperature absorption refrigerators according to the engine cooling water temperature and the heat pump operation mode. Each waste heat recovery device is responsible for different functional requirements, such as heating, ultra-low temperature heating, and domestic hot water. The low-temperature absorption refrigeration system is responsible for utilizing waste heat to improve the refrigeration capacity of the unit to realize the multi-generation operation of the heat pump system; according to the heat pump operation mode, the direction of the engine waste heat is automatically adjusted and controlled to realize the efficient operation of the heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a structural diagram of the wide temperature range air source heat pump waste heat efficient utilization system of the present invention. DETAILED DESCRIPTION

[0014] The present invention will be further described below with reference to the accompanying drawings and preferred specific embodiments of the present invention.

[0015] Reference Figure 1As shown in the , the present invention discloses a wide temperature range air source heat pump waste heat efficient utilization system, which, in addition to including a heat pump device for cooling or heating and an engine for driving the heat pump device, also includes a low-temperature absorption refrigeration module for absorbing engine waste heat for cooling, a hot water heat exchange system for heat exchange using system heat, and a control system for controlling the operation of the heat pump device, the low-temperature absorption refrigeration module, the engine and the hot water heat exchange system.

[0016] The principle of low-temperature absorption refrigeration module for cooling air-conditioning water is different from the refrigeration principle of heat pump device that consumes mechanical energy by using vapor compression refrigerator. Instead, it absorbs the waste heat of the engine. The absorbent solution with lower concentration enters the generator and is heated by the cooling water that absorbs the waste heat of the engine. The high-temperature and high-pressure water vapor generated in the generator enters the condenser, releases heat and is cooled and liquefied to become high-pressure liquid water; the high-pressure liquid water is reduced in pressure by the throttle valve and enters the evaporator. Under the low-pressure environment, the liquid water quickly evaporates into water vapor. The evaporation process absorbs the heat of the air-conditioning water, which reduces the temperature of the air-conditioning water. Finally, the cold energy is sent into the room through the fan to achieve refrigeration; the low-temperature absorption refrigeration module is only turned on when the heat pump device is in the cooling operation state.

[0017] The hot water heat exchange system includes a cylinder water heat exchanger arranged outside the engine cylinder liner, an exhaust gas heat energy heat exchanger PHE5 arranged on the engine exhaust pipe, a domestic hot water heat exchanger PHE3 for providing heat exchange for domestic water, a heating water heat exchanger PHE2 for heat exchange of heating water, a radiator for providing heat dissipation for the engine circulating water, and an engine cooling water pump for driving the engine cooling water to circulate through the radiator, or through the domestic hot water heat exchanger PHE3, or through the heating water heat exchanger PHE2 and the low-temperature absorption refrigeration module. The hot water heat exchange system also includes a first thermostat, a second thermostat, a third solenoid valve, a second solenoid valve, a fifth solenoid valve and a sixth solenoid valve; wherein, the first thermostat is arranged between the cylinder jacket water heat exchanger and the radiator, and when the engine cooling water is greater than a preset value M, the engine cooling water is opened to circulate through the radiator; the second thermostat is arranged at the inlet connected to the first thermostat, one of the outlets is directly connected to the cylinder jacket water heat exchanger through the engine cooling water pump and the exhaust gas heat energy heat exchanger PHE5, and the other outlet is connected to the domestic hot water heat exchanger PHE3 and the heating water heat exchanger PHE2; when the engine cooling water is lower than the preset value N, the cylinder jacket water heat exchanger output The engine cooling water is driven by the engine cooling water pump and directly returns to the exhaust gas heat energy exchanger PHE5 through the first thermostat and the second thermostat without heat recovery; when the engine cooling water is higher than the preset value N, the engine cooling water entering from the second thermostat inlet is subjected to heat energy recovery in the domestic hot water heat exchanger PHE3, the heating water heat exchanger PHE2 or the low-temperature absorption refrigeration module; the third solenoid valve controls the waste heat inlet of the domestic hot water heat exchanger PHE3; the second solenoid valve controls the water inlet of the heating water heat exchanger PHE2; the fifth solenoid valve and the sixth solenoid valve are connected to control the low-temperature absorption refrigeration module to access or exit the engine cooling water circulation pipeline.

[0018] In order to ensure that the heat pump device of the present invention can operate reliably and stably in a low temperature environment below -10°C, the hot water heat exchange system also includes a refrigerant heat exchanger PHE4 connected in parallel with the domestic hot water heat exchanger PHE3 and the heating water heat exchanger PHE2 for heat exchange with the refrigerant of the heat pump device. A fourth solenoid valve SV4 is provided at the inlet of the refrigerant heat exchanger PHE4. When the fourth solenoid valve SV4 is open, the cooling water that absorbs the waste heat of the engine will enter the refrigerant heat exchanger PHE4 and exchange heat with the low-temperature and low-pressure refrigerant of the heat pump device to increase the low-pressure pressure of the system.

[0019] The operating principle of the wide temperature range air source heat pump waste heat efficient utilization system of the present invention is that during the operation of the engine, the engine cooling water pump provides power for the engine cooling water circulation, and the engine cooling water recovers the engine cylinder liner waste heat in the cylinder liner water heat exchanger, and then passes through the first thermostat 1. If the cooling water temperature is greater than or equal to 83°C, the flow path from the first thermostat 1 to the radiator is opened, and the flow path to the second thermostat 2 is closed. The cooling water flows through the radiator and is cooled by the cooling fan, and then flows to the exhaust gas heat energy heat exchanger PHE5 to recover the waste heat in the engine exhaust gas, and finally returns to the cylinder liner water heat exchanger to complete the cycle. If the cooling water temperature is less than 83°C, the flow path from the first thermostat 1 to the second thermostat 2 is opened, and the flow path to the radiator is closed; if the cooling water temperature flowing to the second thermostat 2 is lower than 71°C, in order to ensure the high thermal efficiency of the engine, the waste heat recovery is not performed, the flow path from the second thermostat 2 to the exhaust gas heat exchanger PHE5 is opened, and the flow paths to the heating water heat exchanger PHE2, the domestic hot water heat exchanger PHE3 and the refrigerant heat exchanger PHE4 are all closed, and the cooling water flows directly to the exhaust gas heat exchanger PHE5 to recover the waste heat in the engine exhaust gas, and finally returns to the cylinder jacket water heat exchanger to complete the cycle. If the temperature of the cooling water flowing to the second thermostat 2 is greater than or equal to 71°C, the flow path from the second thermostat 2 to the heating water heat exchanger PHE2, the domestic hot water heat exchanger PHE3 and the refrigerant heat exchanger PHE4 is opened as needed, and the waste heat is recovered and utilized according to different operating modes of the heat pump. The cooling water with the recovered waste heat is then passed to the exhaust gas heat energy heat exchanger PHE5 to recover the waste heat in the engine exhaust gas again, and finally returns to the cylinder jacket water heat exchanger to complete the cycle.

[0020] The present invention is directed to a control method for the wide temperature range air source heat pump waste heat efficient utilization system, including control methods under four control modes: cooling, cooling + domestic hot water, heating, and heating + domestic hot water; wherein: (1) The cooling mode control method is: Select "Cooling" in the control system interface mode, turn off the domestic hot water function switch, and click "Start" for 5 seconds. The second solenoid valve SV2, the third solenoid valve SV3, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 are closed, and the sixth solenoid valve SV6 is opened. The low-temperature absorption refrigeration module is connected to the engine cooling water circulation pipeline. After that, the engine is started and the heat pump device enters normal cooling mode and starts running. When the engine starts and runs until the cooling water temperature Tliq ≥ 71°C for 60 seconds, the fifth solenoid valve SV5 opens. After 5 seconds, the sixth solenoid valve SV6 closes. After the fifth solenoid valve SV5 opens for 10 seconds, the low-temperature absorption refrigeration module starts running. During the operation, the output load is normally adjusted according to the following control: (1) 71℃≤Tliq<75℃, low-temperature absorption refrigeration module output load 50%; (2) 75℃≤Tliq<80℃, the output load of the low-temperature absorption refrigeration module is 75%; (3) Tliq ≥ 80℃, low-temperature absorption refrigeration module output load 100%; (4) Tliq < 71°C for 120 seconds, low-temperature absorption refrigeration module output load 0%; When the system is in standby mode or shut down, the heat pump device is shut down in normal cooling mode. After the engine stops for 60 seconds, the low-temperature absorption refrigeration module is turned off again, so that the residual heat of the engine can be recovered as much as possible.

[0021] (2) The control method of cooling + hot water mode is: Select "Cooling" in the control system interface mode, turn on the domestic hot water function switch, and after clicking "Power on" for 5 seconds, the second solenoid valve SV2, the fourth solenoid valve SV4 and the fifth solenoid valve SV5 are closed, and the third solenoid valve SV3 and the sixth solenoid valve SV6 are opened. The heat pump device starts to operate in normal cooling mode. At this time, there is a demand for cooling and hot water, and the engine waste heat is used to produce hot water to meet the hot water demand.

[0022] When the engine starts and runs until the cooling water temperature Tliq ≥ 75°C for 60 seconds, the fifth solenoid valve SV5 opens, and 5 seconds later the sixth solenoid valve SV6 closes, and the low-temperature absorption refrigeration module is connected to the engine cooling water circulation pipeline. After the fifth solenoid valve SV5 is opened for 10 seconds, the low-temperature absorption refrigeration module starts running, and the output load is adjusted according to the same output load adjustment conditions as the cooling mode control method; During operation, the third solenoid valve SV3 performs control according to the domestic hot water inlet temperature Thwi and the set temperature Ths, and the set temperature Ths is set to a maximum of 70°C; When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; When the third solenoid valve SV3 is closed and Thwi is less than Ths-5°C for 60 seconds, the third solenoid valve SV3 opens. When the third solenoid valve SV3 is in the open state, if Ths-5℃≤Thwi<Ths+2℃ for 30 minutes, the output load of the low-temperature absorption refrigeration module is adjusted to 0% until the third solenoid valve SV3 is closed, and the output load of the low-temperature absorption refrigeration module returns to normal regulation; When the system is in standby mode or shut down, the heat pump unit shuts down in normal cooling mode, and the low-temperature absorption refrigeration module shuts down 60 seconds after the engine stops.

[0023] (3) The heating mode control method is: Select "Heating" in the control system interface mode, turn off the domestic hot water function switch, and click "Start" for 5 seconds. Then, run the program according to the ambient temperature: (a) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be ≥ -10°C, the third solenoid valve SV3, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 are closed, the second solenoid valve SV2 and the sixth solenoid valve SV6 are opened, and the heat pump unit starts to operate in normal heating mode. The low-temperature absorption cooling module remains closed; the cooling water flows through the heating water heat exchanger PHE2 to heat the heating water; At this time, the engine waste heat can be recycled for heating. When the third solenoid valve SV3, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 are closed, the engine cooling water does not exchange heat with the refrigerant and domestic hot water, nor does it enter the low-temperature absorption refrigeration module. The second solenoid valve SV2 and the sixth solenoid valve SV6 are open, and the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water.

[0024] (b) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be less than -10℃, the third solenoid valve SV3 and the fifth solenoid valve SV5 are closed, the second solenoid valve SV2 and the sixth solenoid valve SV6 are opened, the heat pump device starts to operate in normal heating mode, and the low-temperature absorption refrigeration module remains closed; the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the fourth solenoid valve SV4 is opened, and the cooling water flows through the refrigerant heat exchanger PHE4 to exchange heat with the refrigerant of the heat pump; at this time, the waste heat of the engine can be recycled for heating and to increase the low pressure of the heat pump system, so that the wide temperature range air source heat pump device can operate reliably and stably at a lower ambient temperature.

[0025] (4) The control method of heating + hot water mode is: Select "Heating" in the control system interface mode, turn on the domestic hot water function switch, and click "Start" for 5 seconds. Then, run the program according to the ambient temperature: (a) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be ≥ -10°C, the fourth solenoid valve SV4 and the fifth solenoid valve SV5 are closed, the second solenoid valve SV2, the third solenoid valve SV3, and the sixth solenoid valve SV6 are opened, and the heat pump device starts to operate in normal heating mode. The low-temperature absorption cooling module remains closed. During operation, the third solenoid valve SV3 is controlled according to the domestic hot water inlet temperature Thwi and the set temperature Ths, with Ths being set at a maximum of 60°C; When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; After the third solenoid valve SV3 is closed, when Thwi < Ths - 5°C for 60 seconds, the third solenoid valve SV3 opens; at this time, the engine cooling water does not exchange heat with the refrigerant, nor does it enter the low-temperature absorption refrigeration module. The second solenoid valve SV2 opens, and the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the third solenoid valve SV3 opens, and the cooling water flows through the domestic hot water heat exchanger PHE3 to exchange heat with the domestic hot water to heat the hot water; (b) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be less than -10°C, the fifth solenoid valve SV5 closes, the second solenoid valve SV2, the third solenoid valve SV3, the fourth solenoid valve SV4, and the sixth solenoid valve SV6 open, the heat pump device starts operating in normal heating mode, and the low-temperature absorption cooling module remains closed; During operation, the third solenoid valve SV3 is controlled according to the domestic hot water inlet temperature Thwi and the set temperature Ths, with Ths set to a maximum of 50°C: When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; After the third solenoid valve SV3 is closed, when Thwi<Ths-5℃ continues for 60s, the third solenoid valve SV3 opens; at this time, the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the cooling water flows through the domestic hot water heat exchanger PHE3 to exchange heat with the domestic hot water to heat the hot water. To ensure sufficient heating effect, the domestic hot water is allowed to have a maximum set temperature of 50℃; the cooling water flows through PHE4 to exchange heat with the refrigerant of the heat pump, increasing the low pressure of the system, so that the wide temperature range air source heat pump can operate reliably and stably at a lower ambient temperature; the fifth solenoid valve SV5 is closed, and the cooling water does not enter the low-temperature absorption refrigeration module.

[0026] The present invention realizes the multi-generation operation of the heat pump system through the above control method; according to the heat pump operation mode, the direction of the engine waste heat is automatically adjusted and controlled to realize the efficient operation of the heat pump system.

Claims

1. A wide-temperature-range air-source heat pump waste heat efficient utilization system, comprising a heat pump device for cooling or heating and an engine for driving the heat pump device, characterized in that: The wide temperature range air source heat pump waste heat efficient utilization system also includes a low-temperature absorption refrigeration module for absorbing engine waste heat for refrigeration, a hot water heat exchange system for heat exchange using system heat, and a control system for controlling the operation of the heat pump device, the low-temperature absorption refrigeration module, the engine and the hot water heat exchange system; The hot water heat exchange system includes a cylinder water heat exchanger arranged outside the engine cylinder liner, an exhaust gas heat energy heat exchanger PHE5 arranged on the engine exhaust pipe, a domestic hot water heat exchanger PHE3 for providing heat exchange for domestic water, a heating water heat exchanger PHE2 for heat exchange of heating water, a radiator for providing heat dissipation for the engine circulating water, and an engine cooling water pump for driving the engine cooling water to circulate through the radiator, or through the domestic hot water heat exchanger PHE3, or through the heating water heat exchanger PHE2 and the low-temperature absorption refrigeration module.

2. The wide temperature range air source heat pump waste heat efficient utilization system according to claim 1, characterized in that: The hot water heat exchange system also includes a first thermostat, a second thermostat, a third solenoid valve, a second solenoid valve, a fifth solenoid valve and a sixth solenoid valve; wherein, the first thermostat is arranged between the cylinder jacket water heat exchanger and the radiator, and when the engine cooling water is greater than a preset value M, the engine cooling water is opened to circulate through the radiator; the second thermostat is arranged at the inlet connected to the first thermostat, one of the outlets is directly connected to the cylinder jacket water heat exchanger through the engine cooling water pump and the exhaust gas heat energy heat exchanger PHE5, and the other outlet is connected to the domestic hot water heat exchanger PHE3 and the heating water heat exchanger PHE2; when the engine cooling water is lower than the preset value N, the cylinder jacket water heat exchanger output The engine cooling water is driven by the engine cooling water pump and directly returns to the exhaust gas heat energy exchanger PHE5 through the first thermostat and the second thermostat without heat recovery; when the engine cooling water is higher than the preset value N, the engine cooling water entering from the second thermostat inlet is subjected to heat energy recovery in the domestic hot water heat exchanger PHE3, the heating water heat exchanger PHE2 or the low-temperature absorption refrigeration module; the third solenoid valve controls the waste heat inlet of the domestic hot water heat exchanger PHE3; the second solenoid valve controls the water inlet of the heating water heat exchanger PHE2; the fifth solenoid valve and the sixth solenoid valve are connected to control the low-temperature absorption refrigeration module to access or exit the engine cooling water circulation pipeline.

3. The wide temperature range air source heat pump waste heat efficient utilization system according to claim 2, characterized in that: The hot water heat exchange system also includes a refrigerant heat exchanger PHE4 connected in parallel with the domestic hot water heat exchanger PHE3 and the heating water heat exchanger PHE2 for heat exchange with the refrigerant of the heat pump device. A fourth solenoid valve SV4 is provided at the inlet of the refrigerant heat exchanger PHE4.

4. The control method of the wide temperature range air source heat pump waste heat efficient utilization system according to claim 3 is characterized by: The control system includes control methods under four control modes: cooling, cooling + domestic hot water, heating, and heating + domestic hot water; wherein: (1) The cooling mode control method is: Select "Cooling" on the control system's interface mode, turn off the domestic hot water function switch, and click "Start." The second, third, fourth, and fifth solenoid valves SV2, SV3, SV4, and SV5 are closed, while the sixth solenoid valve SV6 is opened. The low-temperature absorption refrigeration module is connected to the engine cooling water circulation pipeline. The engine is then started, and the heat pump unit enters normal cooling mode and starts operating. When the engine starts and runs until the cooling water temperature Tliq ≥ 71°C for 60 seconds, the fifth solenoid valve SV5 opens. After 5 seconds, the sixth solenoid valve SV6 closes. After the fifth solenoid valve SV5 opens for 10 seconds, the low-temperature absorption refrigeration module starts running. During the operation, the output load is normally adjusted according to the following control: (1) 71℃≤Tliq<75℃, low-temperature absorption refrigeration module output load 50%; (2) 75℃≤Tliq<80℃, the output load of the low-temperature absorption refrigeration module is 75%; (3) Tliq ≥ 80℃, low-temperature absorption refrigeration module output load 100%; (4) Tliq < 71°C for 120 seconds, low-temperature absorption refrigeration module output load 0%; When the system is in standby mode or shut down, the heat pump unit shuts down in normal cooling mode, and after the engine stops, the low-temperature absorption refrigeration module shuts down again; (2) The control method of cooling + hot water mode is: Select "Cooling" in the control system interface mode, turn on the domestic hot water function switch, and after clicking "Start", the second solenoid valve SV2, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 are closed, and the third solenoid valve SV3 and the sixth solenoid valve SV6 are opened. The heat pump device starts to operate in normal cooling mode. When the engine starts and runs until the cooling water temperature Tliq ≥ 75°C for 60 seconds, the fifth solenoid valve SV5 is opened. After 5 seconds, the sixth solenoid valve SV6 is closed. The low-temperature absorption refrigeration module is connected to the engine cooling water circulation pipeline. After the fifth solenoid valve SV5 is opened for 10 seconds, the low-temperature absorption refrigeration module starts to operate. The output load adjustment conditions are the same as those of the cooling mode control method. During operation, the third solenoid valve SV3 performs control according to the domestic hot water inlet temperature Thwi and the set temperature Ths, and the set temperature Ths is set to a maximum of 70°C; When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; When the third solenoid valve SV3 is closed and Thwi is less than Ths-5°C for 60 seconds, the third solenoid valve SV3 opens. When the third solenoid valve SV3 is in the open state, if Ths-5℃≤Thwi<Ths+2℃ for 30 minutes, the output load of the low-temperature absorption refrigeration module is adjusted to 0% until the third solenoid valve SV3 is closed, and the output load of the low-temperature absorption refrigeration module returns to normal regulation; When the system is in standby or shutdown mode, the heat pump unit is shut down in normal cooling mode, and the low-temperature absorption cooling module is turned off 60 seconds after the engine stops; (3) The heating mode control method is: Select "Heating" in the control system interface mode, turn the domestic hot water function switch to "Off", and click "Start" to run the program based on the ambient temperature: (a) Five seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be ≥ -10°C, the third solenoid valve SV3, the fourth solenoid valve SV4, and the fifth solenoid valve SV5 close, the second solenoid valve SV2 and the sixth solenoid valve SV6 open, and the heat pump unit starts operating in normal heating mode. The low-temperature absorption cooling module remains closed; cooling water flows through the heating water heat exchanger PHE2 to heat the heating water. (b) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be less than -10°C, the third solenoid valve SV3 and the fifth solenoid valve SV5 close, the second solenoid valve SV2 and the sixth solenoid valve SV6 open, and the heat pump unit starts operating in normal heating mode. The low-temperature absorption cooling module remains closed; the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the fourth solenoid valve SV4 opens, and the cooling water flows through the refrigerant heat exchanger PHE4 to exchange heat with the refrigerant of the heat pump; (4) The control method of heating + hot water mode is: Select "Heating" in the control system interface mode, turn on the domestic hot water function switch, and click "Start" to run the program based on the ambient temperature: (a) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be ≥ -10°C, the fourth solenoid valve SV4 and the fifth solenoid valve SV5 are closed, the second solenoid valve SV2, the third solenoid valve SV3, and the sixth solenoid valve SV6 are opened, and the heat pump unit starts operating in normal heating mode. The low-temperature absorption cooling module remains closed. During operation, the third solenoid valve SV3 is controlled according to the domestic hot water inlet temperature Thwi and the set temperature Ths, with Ths being set at a maximum of 60°C; When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; After the third solenoid valve SV3 is closed, when Thwi < Ths - 5°C for 60 seconds, the third solenoid valve SV3 opens; the engine cooling water does not exchange heat with the refrigerant, nor does it enter the low-temperature absorption refrigeration module. The second solenoid valve SV2 opens, and the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the third solenoid valve SV3 opens, and the cooling water flows through the domestic hot water heat exchanger PHE3 to exchange heat with the domestic hot water to heat the hot water; (b) 5 seconds after the "start" command is issued, when the outdoor ambient temperature Tao is detected to be less than -10°C, the fifth solenoid valve SV5 closes, the second solenoid valve SV2, the third solenoid valve SV3, the fourth solenoid valve SV4, and the sixth solenoid valve SV6 open, and the heat pump unit starts operating in normal heating mode. The low-temperature absorption cooling module remains closed. During operation, the third solenoid valve SV3 is controlled according to the domestic hot water inlet temperature Thwi and the set temperature Ths, with Ths set to a maximum of 50°C: When Thwi≥Ths+2℃ for 60s, the third solenoid valve SV3 is closed; After the third solenoid valve SV3 is closed, when Thwi<Ths-5℃ continues for 60s, the third solenoid valve SV3 opens; the cooling water flows through the heating water heat exchanger PHE2 to exchange heat with the heat pump heating water to heat the heating water; the cooling water flows through the domestic hot water heat exchanger PHE3 to exchange heat with the domestic hot water to heat the hot water; the cooling water flows through PHE4 to exchange heat with the refrigerant of the heat pump.

5. The control method of a wide temperature range air source heat pump waste heat efficient utilization system according to claim 4, characterized in that: In heating + hot water mode, the maximum set temperature allowed for domestic hot water is 50°C.

Images