Vehicle cascade type waste heat refrigerating system and vehicle

Abstract

The invention relates to the technical field of heat management, and provides a vehicle cascade type waste heat refrigerating system and a vehicle, the vehicle cascade type waste heat refrigerating system comprises a waste heat source loop and a refrigerating loop, and the waste heat source loop comprises a waste heat exchanger and a secondary refrigerant pump; the refrigerating circuit comprises a high-temperature stage circuit, an interstage heat exchanger and a low-temperature stage circuit; and at least one of the high-temperature-stage supercharging device in the high-temperature-stage loop and the low-temperature-stage supercharging device in the low-temperature-stage loop increases the pressure of a refrigerant of the refrigerating loop by using the heat of a secondary refrigerant of the waste heat exchanger. Therefore, the heat of the waste heat source is recycled and utilized, the problem of energy waste is effectively avoided, and the heat dissipation pressure of the heat management system is reduced. And moreover, a double-temperature-zone coupling refrigeration cycle structure is constructed, the waste heat refrigeration temperature span is greatly increased, efficient refrigeration under the working conditions of high condensation temperature and proper evaporation temperature is achieved, the refrigeration requirement of an automobile in a high-temperature environment is met, and the working condition adaptability and operation stability of the system are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology, and in particular to a cascade waste heat refrigeration system for vehicles and a vehicle thereof. Background Technology

[0002] Energy structure transformation and the construction of a clean energy system are important development trends in the global energy sector. As a key carrier of clean energy transportation, new energy vehicles play a crucial role in promoting energy structure optimization and carbon reduction in the transportation sector.

[0003] During the operation of new energy vehicles, the electric drive system, power battery, and fuel cell system all generate waste heat of different forms and temperature levels. If this waste heat is not effectively recovered and utilized, it will not only lead to significant energy waste, but also increase the heat dissipation pressure on the thermal management system, thereby affecting the performance stability and service life of key components and reducing the overall vehicle's operational stability and reliability.

[0004] Therefore, how to recover and utilize vehicle waste heat is an important issue that the industry urgently needs to address. Summary of the Invention

[0005] This invention provides a cascade waste heat refrigeration system and vehicle for use in vehicles, which can recover and utilize vehicle waste heat, avoid energy waste, and reduce the heat dissipation pressure of the thermal management system.

[0006] This invention provides a cascade waste heat refrigeration system for vehicles, comprising: The waste heat source circuit is suitable for supplying refrigerant circulation. The waste heat source circuit includes a waste heat exchanger and a refrigerant pump. The waste heat exchanger is suitable for supplying heat exchange between the refrigerant and the waste heat source. The refrigerant pump is suitable for driving the refrigerant to circulate. A refrigeration circuit includes a high-temperature stage circuit, an interstage heat exchanger, and a low-temperature stage circuit. The high-temperature stage circuit includes a high-temperature stage booster, a high-temperature stage condenser, and a high-temperature stage expansion valve. The refrigerant passage of the high-temperature stage booster, the refrigerant passage of the high-temperature stage condenser, the high-temperature stage expansion valve, and the first refrigerant passage of the interstage heat exchanger are connected. The low-temperature stage circuit includes a low-temperature stage booster, a low-temperature stage evaporator, and a low-temperature stage expansion valve. The refrigerant passage of the low-temperature stage booster, the second refrigerant passage of the interstage heat exchanger, the low-temperature stage expansion valve, and the refrigerant passage of the low-temperature stage evaporator are connected. At least one of the high-temperature stage booster device and the low-temperature stage booster device is adapted to increase the pressure of the refrigerant in the refrigeration circuit by utilizing the heat of the refrigerant in the waste heat exchanger.

[0007] According to the present invention, a cascade waste heat refrigeration system for vehicles includes a high-temperature stage booster device comprising: A high-temperature steam generator, wherein the refrigerant channel of the high-temperature steam generator is connected to the refrigerant pump and the waste heat exchanger; A high-temperature refrigerant pump, wherein the inlet of the high-temperature refrigerant pump and the high-temperature expansion valve are both connected to the refrigerant passage of the high-temperature condenser, and the outlet of the high-temperature refrigerant pump is connected to the refrigerant passage of the high-temperature steam generator; The high-temperature stage ejector has its main inlet connected to the refrigerant channel of the high-temperature stage steam generator, its ejector port connected to the first refrigerant channel of the interstage heat exchanger, and its outlet connected to the refrigerant channel of the high-temperature stage condenser.

[0008] According to the present invention, a cascade waste heat refrigeration system for vehicles includes a cryogenic stage booster device comprising: A cryogenic steam generator, wherein the refrigerant channel of the cryogenic steam generator is connected to the refrigerant pump and the waste heat exchanger; A low-temperature stage refrigerant pump, wherein the inlet of the low-temperature stage refrigerant pump and the low-temperature stage expansion valve are both connected to the second refrigerant channel of the interstage heat exchanger, and the outlet of the low-temperature stage refrigerant pump is connected to the refrigerant channel of the low-temperature stage steam generator; The cryogenic stage ejector has its main inlet connected to the refrigerant channel of the cryogenic stage steam generator, its ejector port connected to the refrigerant channel of the cryogenic stage evaporator, and its outlet connected to the second refrigerant channel of the interstage heat exchanger.

[0009] According to the present invention, a cascade waste heat cooling system for vehicles further includes: The third three-way valve has its inlet connected to one end of the refrigerant channel of the high-temperature steam generator, the other end of the refrigerant channel of the high-temperature steam generator connected to the refrigerant pump, and its second outlet connected to one end of the refrigerant channel of the low-temperature steam generator. The other end of the refrigerant channel of the low-temperature steam generator and the first outlet of the third three-way valve are both connected to the refrigerant channel of the waste heat exchanger. The inlet of the third three-way valve can be selectively connected to either the first outlet or the second outlet of the third three-way valve.

[0010] According to the present invention, a cascade waste heat refrigeration system for vehicles further includes a cryogenic stage booster device: compressor; The first three-way valve has its inlet connected to the exhaust port of the compressor, and its first outlet and the outlet of the cryogenic stage ejector are both connected to the second refrigerant passage of the interstage heat exchanger. The inlet of the first three-way valve may be selectively connected to one of the first outlet and the second outlet of the first three-way valve. The second three-way valve has its inlet connected to the refrigerant passage of the low-temperature evaporator, its first outlet connected to the suction port of the compressor, and both the second outlet of the first three-way valve and the second outlet of the second three-way valve connected to the ejector port of the low-temperature ejector. The inlet of the second three-way valve may optionally be connected to one of the first outlet and the second outlet of the second three-way valve.

[0011] A cascade waste heat refrigeration system for vehicles according to the present invention further includes: The controller includes the first three-way valve, the second three-way valve, and the third three-way valve, all of which are electric valves. The first three-way valve, the second three-way valve, the third three-way valve, the refrigerant pump, the high-temperature refrigerant pump, the low-temperature refrigerant pump, and the compressor are all electrically connected to the controller.

[0012] According to the present invention, a cascade waste heat refrigeration system for vehicles is provided, wherein the refrigerant in the high-temperature stage circuit is a first refrigerant, and the refrigerant in the low-temperature stage circuit is a second refrigerant, wherein the boiling point of the first refrigerant is greater than that of the second refrigerant.

[0013] According to the present invention, a cascade waste heat refrigeration system for vehicles is provided, wherein the refrigerant in the waste heat source circuit includes water, an aqueous alcohol solution, or an aqueous salt solution.

[0014] According to the present invention, a cascade waste heat cooling system for vehicles includes at least one of an electric drive system and a battery system as the waste heat source.

[0015] The present invention also provides a vehicle including the above-described vehicle cascade waste heat refrigeration system.

[0016] The present invention provides a cascade waste heat refrigeration system for vehicles, comprising a waste heat source circuit and a refrigeration circuit. The waste heat source circuit is used for the circulation of refrigerant, and the refrigeration circuit is used for the circulation of coolant. The waste heat source circuit includes a waste heat exchanger and a refrigerant pump. The waste heat exchanger is used for heat exchange between the refrigerant and the waste heat source, whereby the refrigerant absorbs heat from the waste heat source, transferring the heat from the waste heat source to the refrigerant. The refrigerant pump is used to drive the refrigerant to circulate and absorb heat from the waste heat source. The refrigeration circuit includes a high-temperature stage circuit, an interstage heat exchanger, and a low-temperature stage circuit. The interstage heat exchanger has a first refrigerant channel and a second refrigerant channel capable of heat exchange. The first refrigerant channel corresponds to the high-temperature stage circuit, and the second refrigerant channel corresponds to the low-temperature stage circuit. The high-temperature stage circuit includes a high-temperature stage booster, a high-temperature stage condenser, and a high-temperature stage expansion valve. The refrigerant channels of the high-temperature stage booster, the high-temperature stage condenser, the high-temperature stage expansion valve, and the first refrigerant channel of the interstage heat exchanger are connected. The low-temperature stage circuit includes a low-temperature stage booster, a low-temperature stage evaporator, and a low-temperature stage expansion valve. The refrigerant passage of the low-temperature stage booster, the second refrigerant passage of the interstage heat exchanger, the low-temperature stage expansion valve, and the refrigerant passage of the low-temperature stage evaporator are connected. At least one of the high-temperature stage booster and the low-temperature stage booster is adapted to utilize the heat of the refrigerant in the waste heat exchanger to increase the pressure of the refrigerant in the refrigeration circuit. Thus, the cascade waste heat refrigeration system for vehicles provided by this invention can utilize the heat from the waste heat source for refrigeration, realizing the recovery and utilization of the heat from the waste heat source, effectively avoiding the problem of energy waste, and reducing the heat dissipation pressure of the thermal management system, which is beneficial to improving the operational stability and reliability of the entire vehicle.

[0017] Furthermore, the vehicle provided by the present invention possesses the same advantages as described above, due to the presence of the vehicle-mounted cascade waste heat cooling system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the vehicle cascade waste heat refrigeration system provided by the present invention.

[0020] Figure 2 This is a schematic diagram of the vehicle cascade waste heat refrigeration system provided by the present invention in its first state.

[0021] Figure 3 This is a schematic diagram of the vehicle cascade waste heat refrigeration system provided by the present invention in its second state.

[0022] Figure 4 This is a schematic diagram of the vehicle cascade waste heat refrigeration system provided by the present invention in its third state.

[0023] Figure 5 This is the pressure-enthalpy diagram of the high-temperature stage circuit of the automotive cascade waste heat refrigeration system provided by the present invention when it is operating in the second state.

[0024] Figure 6 This is the pressure-enthalpy diagram of the low-temperature stage circuit when the vehicle cascade waste heat refrigeration system provided by the present invention is operating in the second state.

[0025] Figure label: 1. Waste heat exchanger; 2. Refrigerant pump; 3. Interstage heat exchanger; 4. High-temperature stage condenser; 5. High-temperature stage expansion valve; 6. Low-temperature stage evaporator; 7. Low-temperature stage expansion valve; 8. High-temperature stage steam generator; 9. High-temperature stage refrigerant pump; 10. High-temperature stage ejector; 11. Low-temperature stage steam generator; 12. Low-temperature stage refrigerant pump; 13. Low-temperature stage ejector; 14. Third three-way valve; 15. Compressor; 16. First three-way valve; 17. Second three-way valve. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] The following is combined Figures 1 to 6 The present invention describes a vehicle-mounted cascade waste heat refrigeration system.

[0028] like Figures 1 to 6 As shown, the vehicle-mounted cascade waste heat refrigeration system provided in this embodiment of the invention includes a waste heat source circuit and a refrigeration circuit.

[0029] Specifically, the waste heat source circuit is used to supply the refrigerant, and the refrigeration circuit is used to supply the refrigerant.

[0030] The waste heat source circuit includes a waste heat exchanger 1 and a refrigerant pump 2. The waste heat exchanger 1 is used to supply heat exchange between the refrigerant and the waste heat source. The refrigerant absorbs the heat from the waste heat source and transfers the heat from the waste heat source to the refrigerant.

[0031] The refrigerant pump 2 is used to drive the refrigerant to circulate and absorb heat from the waste heat source.

[0032] The refrigeration circuit includes a high-temperature stage circuit, an interstage heat exchanger 3, and a low-temperature stage circuit.

[0033] The interstage heat exchanger 3 has a first refrigerant channel and a second refrigerant channel that can exchange heat. The first refrigerant channel corresponds to the high-temperature stage circuit, and the second refrigerant channel corresponds to the low-temperature stage circuit. The interstage heat exchanger 3 is used to allow the refrigerant in the high-temperature stage circuit to exchange heat with the refrigerant in the low-temperature stage circuit.

[0034] The high-temperature stage circuit includes a high-temperature stage booster, a high-temperature stage condenser 4, and a high-temperature stage expansion valve 5. The refrigerant passages of the high-temperature stage booster, the high-temperature stage condenser 4, the high-temperature stage expansion valve 5, and the first refrigerant passage of the interstage heat exchanger 3 are connected. The refrigerant in the high-temperature stage circuit circulates through the refrigerant passages of the high-temperature stage booster, the high-temperature stage condenser 4, the high-temperature stage expansion valve 5, and the first refrigerant passage of the interstage heat exchanger 3.

[0035] The low-temperature stage circuit includes a low-temperature stage booster unit, a low-temperature stage evaporator 6, and a low-temperature stage expansion valve 7. The refrigerant passages of the low-temperature stage booster unit, the second refrigerant passage of the interstage heat exchanger 3, the low-temperature stage expansion valve 7, and the low-temperature stage evaporator 6 are connected. The refrigerant in the low-temperature stage circuit circulates through the refrigerant passages of the low-temperature stage booster unit, the second refrigerant passage of the interstage heat exchanger 3, the low-temperature stage expansion valve 7, and the low-temperature stage evaporator 6.

[0036] At least one of the high-temperature stage booster and the low-temperature stage booster is adapted to increase the pressure of the refrigerant in the refrigeration circuit by utilizing the heat of the refrigerant in the waste heat exchanger 1.

[0037] The aforementioned high-temperature stage condenser 4 is located outside the passenger compartment. The high-temperature stage condenser 4 exchanges heat with the air in the external environment and releases heat to the external environment. The aforementioned low-temperature stage evaporator 6 is located inside the passenger compartment. The low-temperature stage evaporator 6 exchanges heat with the air inside the passenger compartment and releases cooling energy into the passenger compartment.

[0038] With this configuration, the vehicle cascade waste heat cooling system provided in this embodiment of the invention can utilize the heat from the waste heat source for cooling, realizing the recovery and utilization of the heat from the waste heat source, effectively avoiding the problem of energy waste, and reducing the heat dissipation pressure of the thermal management system, which is conducive to improving the operational stability and reliability of the vehicle.

[0039] In this embodiment of the invention, the high-temperature stage pressurization device includes a high-temperature stage steam generator 8, a high-temperature stage refrigerant pump 9, and a high-temperature stage ejector 10.

[0040] The high-temperature steam generator 8 has a refrigerant channel and a coolant channel. The high-temperature steam generator 8 is used for heat exchange between the coolant in the coolant channel and the refrigerant in the refrigerant channel. The refrigerant channel of the high-temperature steam generator 8 is connected to the refrigerant pump 2 and the waste heat exchanger 1. Driven by the refrigerant pump 2, the refrigerant in the waste heat source circuit circulates between the refrigerant channel of the high-temperature steam generator 8 and the waste heat exchanger 1 to continuously transfer the heat of the refrigerant to the coolant in the high-temperature circuit.

[0041] The inlet of the high-temperature stage refrigerant pump 9 and the high-temperature stage expansion valve 5 are both connected to the refrigerant passage of the high-temperature stage condenser 4. Of the refrigerant output from the high-temperature stage condenser 4, a portion flows to the high-temperature stage refrigerant pump 9, and the other portion flows to the high-temperature stage expansion valve 5. The refrigerant flowing to the high-temperature stage expansion valve 5 will further flow through the first refrigerant passage of the interstage heat exchanger 3 and evaporate within the first refrigerant passage.

[0042] The outlet of the high-temperature refrigerant pump 9 is connected to the refrigerant channel of the high-temperature steam generator 8. The refrigerant flowing to the high-temperature refrigerant pump 9 will further flow through the refrigerant channel of the high-temperature steam generator 8 to absorb the heat of the refrigerant in the refrigerant channel of the high-temperature steam generator 8 and be transformed into high-temperature and high-pressure gas.

[0043] The main inlet of the high-temperature stage ejector 10 is connected to the refrigerant channel of the high-temperature stage steam generator 8, the ejector port of the high-temperature stage ejector 10 is connected to the first refrigerant channel of the interstage heat exchanger 3, and the outlet of the high-temperature stage ejector 10 is connected to the refrigerant channel of the high-temperature stage condenser 4.

[0044] High-temperature, high-pressure gas in the refrigerant channel of the high-temperature steam generator 8 enters the nozzle of the high-temperature ejector 10 and undergoes adiabatic expansion. The pressure energy of the high-temperature, high-pressure gas is converted into kinetic energy, and the high-temperature, high-pressure gas is ejected from the nozzle, forming a high-speed, low-pressure jet. A low-pressure zone is formed at the nozzle outlet, thereby forcing the refrigerant in the first refrigerant channel of the interstage heat exchanger 3 to be drawn into the high-temperature ejector 10. The two fluids mix, and the high-speed, low-pressure jet transfers momentum to the low-speed ejector fluid, gradually mixing to form a mixed fluid with a uniform flow velocity but a velocity lower than that of the high-speed, low-pressure jet. The mixed fluid enters the diffuser chamber of the high-temperature ejector 10, where its velocity decreases, and its kinetic energy is converted into pressure energy, making the pressure at the outlet of the diffuser chamber higher than the pressure at the ejector port, thereby pressurizing the refrigerant.

[0045] Similarly, the cryogenic stage pressurization device includes a cryogenic stage steam generator 11, a cryogenic stage refrigerant pump 12, and a cryogenic stage ejector 13.

[0046] The cryogenic steam generator 11 has a refrigerant channel and a coolant channel. The cryogenic steam generator 11 is used for heat exchange between the coolant in the coolant channel and the refrigerant in the refrigerant channel. The refrigerant channel of the cryogenic steam generator 11 is connected to the refrigerant pump 2 and the waste heat exchanger 1. Driven by the refrigerant pump 2, the refrigerant in the waste heat source circuit circulates between the refrigerant channel of the cryogenic steam generator 11 and the waste heat exchanger 1 to continuously transfer the heat of the refrigerant to the coolant in the cryogenic circuit.

[0047] The inlet of the low-temperature stage refrigerant pump 12 and the low-temperature stage expansion valve 7 are both connected to the second refrigerant channel of the interstage heat exchanger 3. Part of the refrigerant output from the second refrigerant channel of the interstage heat exchanger 3 flows to the low-temperature stage refrigerant pump 12, and the other part flows to the low-temperature stage expansion valve 7. The refrigerant flowing to the low-temperature stage expansion valve 7 further flows to the low-temperature stage evaporator 6, where it evaporates.

[0048] The outlet of the low-temperature refrigerant pump 12 is connected to the refrigerant channel of the low-temperature steam generator 11. The refrigerant flowing to the low-temperature refrigerant pump 12 will further flow through the refrigerant channel of the low-temperature steam generator 11 to absorb the heat of the refrigerant in the refrigerant channel of the low-temperature steam generator 11 and be transformed into high-temperature and high-pressure gas.

[0049] The main inlet of the cryogenic ejector 13 is connected to the refrigerant channel of the cryogenic steam generator 11, the ejector port of the cryogenic ejector 13 is connected to the refrigerant channel of the cryogenic evaporator 6, and the outlet of the cryogenic ejector 13 is connected to the second refrigerant channel of the interstage heat exchanger 3.

[0050] High-temperature, high-pressure gas in the refrigerant passage of the cryogenic steam generator 11 enters the nozzle of the cryogenic ejector 13 and undergoes adiabatic expansion. The pressure energy of the high-temperature, high-pressure gas is converted into kinetic energy, and the high-temperature, high-pressure gas is ejected from the nozzle, forming a high-speed, low-pressure jet. A low-pressure zone is formed at the nozzle outlet, thereby forcing the refrigerant in the refrigerant passage of the cryogenic evaporator 6 to be drawn into the cryogenic ejector 13. The two fluids mix, and the high-speed, low-pressure jet transfers momentum to the low-speed ejector fluid, gradually mixing to form a mixed fluid with a uniform flow velocity but a velocity lower than that of the high-speed, low-pressure jet. The mixed fluid enters the diffuser chamber of the cryogenic ejector 13, where its velocity decreases, and its kinetic energy is converted into pressure energy, making the pressure at the outlet of the diffuser chamber higher than the pressure at the ejector port, thereby pressurizing the refrigerant.

[0051] Both the high-temperature steam generator 8 and the low-temperature steam generator 11 mentioned above can utilize the heat from the waste heat source, which is beneficial for dissipating heat from the waste heat source and achieving temperature control of the waste heat source.

[0052] In a further embodiment, the waste heat source circuit also includes a third three-way valve 14, which has an inlet, a first outlet, and a second outlet. The inlet can be connected to the first outlet, and the inlet can also be connected to the second outlet, but the first outlet and the second outlet cannot be connected. That is, the inlet of the third three-way valve 14 can be selectively connected to one of the first outlet and the second outlet of the third three-way valve 14.

[0053] The inlet of the third three-way valve 14 is connected to one end of the refrigerant passage of the high-temperature steam generator 8, and the other end of the refrigerant passage of the high-temperature steam generator 8 is connected to the refrigerant pump 2. The second outlet of the third three-way valve 14 is connected to one end of the refrigerant passage of the low-temperature steam generator 11, and the other end of the refrigerant passage of the low-temperature steam generator 11 and the first outlet of the third three-way valve 14 are both connected to the refrigerant passage of the waste heat exchanger 1.

[0054] Thus, the third three-way valve 14 connects the refrigerant passage of the high-temperature steam generator 8 with the refrigerant passage of the low-temperature steam generator 11. When the inlet of the third three-way valve 14 is connected to the first outlet, the refrigerant circulates between the waste heat exchanger 1 and the refrigerant passage of the high-temperature steam generator 8 under the drive of the refrigerant pump 2. At this time, the refrigerant does not circulate in the refrigerant passage of the low-temperature steam generator 11. When the inlet of the third three-way valve 14 is connected to the second outlet, the refrigerant circulates between the waste heat exchanger 1, the refrigerant passage of the high-temperature steam generator 8, and the refrigerant passage of the low-temperature steam generator 11 under the drive of the refrigerant pump 2.

[0055] By controlling the connection status of the inlet, first outlet, and second outlet of the third three-way valve 14, it is possible to choose to use the heat from the waste heat source to heat only the high-temperature steam generator 8, or to choose to use the heat from the waste heat source to heat both the high-temperature steam generator 8 and the low-temperature steam generator 11 simultaneously.

[0056] In a further embodiment, the cryogenic stage booster device also includes a compressor 15, a first three-way valve 16, and a second three-way valve 17. The first three-way valve 16 is located at the exhaust port of the compressor 15, and the second three-way valve 17 is located at the intake port of the compressor 15.

[0057] The first three-way valve 16 has an inlet, a first outlet, and a second outlet. The inlet can be connected to the first outlet or the second outlet, but the first outlet and the second outlet cannot be connected. That is, the inlet of the first three-way valve 16 can be selectively connected to either the first outlet or the second outlet of the first three-way valve 16.

[0058] Similarly, the second three-way valve 17 has an inlet, a first outlet, and a second outlet. The inlet can be connected to the first outlet or the second outlet, but the first outlet and the second outlet cannot be connected. In other words, the inlet of the second three-way valve 17 can be selectively connected to either the first outlet or the second outlet of the second three-way valve 17.

[0059] The inlet of the first three-way valve 16 is connected to the exhaust port of the compressor 15, and the first outlet of the first three-way valve 16 and the outlet of the cryogenic stage ejector 13 are both connected to the second refrigerant passage of the interstage heat exchanger 3. The inlet of the second three-way valve 17 is connected to the refrigerant passage of the cryogenic stage evaporator 6, the first outlet of the second three-way valve 17 is connected to the suction port of the compressor 15, and the second outlets of the first three-way valve 16 and the second outlet of the second three-way valve 17 are both connected to the ejector port of the cryogenic stage ejector 13.

[0060] With this configuration, the compressor 15, the first three-way valve 16, and the second three-way valve 17 are set up to regulate the gas pressure at the injection port of the cryogenic stage ejector 13.

[0061] Connect the inlet of the first three-way valve 16 to the first outlet, connect the inlet of the second three-way valve 17 to the second outlet, and connect the inlet of the third three-way valve 14 to the second outlet. At this time, the refrigerant passage of the low-temperature evaporator 6 is directly connected to the injection port of the low-temperature ejector 13, and the exhaust port of the compressor 15 is not connected to the injection port of the low-temperature ejector 13. The refrigerant is pressurized only by the low-temperature ejector 13, and the pressurization is based on the output pressure of the low-temperature evaporator 6. This state is called the first state.

[0062] The inlet of the first three-way valve 16 is connected to the second outlet, the inlet of the second three-way valve 17 is connected to the first outlet, and the inlet of the third three-way valve 14 is connected to the second outlet. At this time, the refrigerant passage of the low-temperature evaporator 6 and the injection port of the low-temperature ejector 13 are connected through the compressor 15. The compressor 15 pressurizes the refrigerant, and simultaneously, the low-temperature ejector 13 pressurizes the refrigerant, based on the output pressure of the compressor 15. The output pressure of the low-temperature ejector 13 in the first state is lower than the output pressure of the low-temperature ejector 13 in the second state; this state is called the second state.

[0063] Connect the inlet of the first three-way valve 16 to the first outlet, connect the inlet of the second three-way valve 17 to the first outlet, and connect the inlet of the third three-way valve 14 to the first outlet. At this time, the refrigerant passage of the low-temperature evaporator 6 is connected to the compressor 15, the refrigerant passage of the low-temperature evaporator 6 is not connected to the injection port of the low-temperature ejector 13, and the refrigerant in the waste heat exchanger 1 will not flow in the low-temperature steam generator 11. Only the compressor 15 is used to pressurize the refrigerant; this state is called the third state.

[0064] When the vehicle-mounted cascade waste heat refrigeration system provided in this embodiment of the invention is running, it can utilize the compressor 15 to pressurize the refrigerant in the low-temperature stage circuit, or it can utilize the low-temperature stage ejector 13 to pressurize the refrigerant in the low-temperature stage circuit, or it can utilize both the compressor 15 and the low-temperature stage ejector 13 simultaneously to pressurize the refrigerant in the low-temperature stage circuit. The specific method depends on the heat source of the waste heat and the refrigeration demand of the refrigeration circuit. The refrigeration demand of the refrigeration circuit can be determined based on the user's set temperature, and the heat source of the waste heat can be determined based on the temperature of the refrigerant in the waste heat exchanger 1.

[0065] In a specific embodiment, the ratio of the heat from the waste heat source to the cooling demand of the refrigeration circuit can be determined; this ratio is called the heat-to-cooling ratio. When the heat-to-cooling ratio is greater than a first ratio, the vehicle cascade waste heat refrigeration system operates in a first state. When the heat-to-cooling ratio is lower than a second ratio, and the second ratio is less than the first ratio, the vehicle cascade waste heat refrigeration system operates in a third state. When the heat-to-cooling ratio is greater than the second ratio and less than the first ratio, the vehicle cascade waste heat refrigeration system operates in a second state.

[0066] The following is combined Figure 5 and Figure 6 The pressure-enthalpy diagram shown describes the working fluid circulation process of a cascade waste heat refrigeration system in an automotive application operating in its second state. The pressure-enthalpy diagram, abbreviated as PH diagram, uses specific enthalpy on the horizontal axis and absolute pressure on the vertical axis.

[0067] like Figure 5 As shown, the gas exiting the high-temperature stage ejector 10 (corresponding to state point A) is cooled by the high-temperature stage condenser 4 and converted into subcooled liquid (corresponding to state point B), then splits into two streams. One stream of subcooled liquid flows through the high-temperature stage refrigerant pump 9 to be pressurized into a high-pressure liquid (corresponding to state point C), and then enters the high-temperature stage steam generator 8 for heating, transforming it into high-temperature, high-pressure gas (corresponding to state point D). This gas then enters the high-temperature stage ejector 10 through the main inlet, where it expands and depressurizes through the nozzle (corresponding to state point E). The other stream of subcooled liquid flows through the high-temperature stage expansion valve 5, throttling it into a low-temperature, low-pressure gas-liquid mixture (corresponding to state point G). This mixture absorbs heat and evaporates into superheated gas in the interstage heat exchanger 3 (corresponding to state point H), then enters the high-temperature stage ejector 10 through the ejector port, mixing with the depressurized fluid at the nozzle (corresponding to state point F). The mixed fluid is then pressurized within the high-temperature stage ejector 10 and discharged (corresponding to state point A), completing the cycle.

[0068] like Figure 6As shown, the gas exiting the cryogenic ejector 13 (corresponding to state point I) enters the second refrigerant channel of the interstage heat exchanger 3 for cooling, transforming into subcooled liquid (corresponding to state point J), and then splits into two paths. One path flows through the cryogenic refrigerant pump 12 to be pressurized into a high-pressure liquid (corresponding to state point K), enters the cryogenic steam generator 11 for heating, transforms into high-temperature, high-pressure gas (corresponding to state point L), and then enters the cryogenic ejector 13 from the main inlet, expanding and depressurizing through the nozzle (corresponding to state point M). The other path of subcooled liquid is throttled by the cryogenic expansion valve 7 into a cryogenic, low-pressure gas-liquid mixture (corresponding to state point O), absorbs heat and evaporates into superheated gas in the cryogenic evaporator 6 (corresponding to state point P), is compressed by the compressor 15 (corresponding to state point Q), and then enters the cryogenic ejector 13 from the ejector port, mixing with the depressurized fluid at the nozzle (corresponding to state point N). The mixed fluid is pressurized again within the cryogenic ejector 13 and then discharged (corresponding to state point I), completing the cycle.

[0069] In this embodiment of the invention, the vehicle-mounted cascade waste heat refrigeration system further includes a controller.

[0070] The first three-way valve 16, the second three-way valve 17, and the third three-way valve 14 are all electric valves; solenoid valves can be selected instead. The first three-way valve 16, the second three-way valve 17, the third three-way valve 14, the refrigerant pump 2, the high-temperature refrigerant pump 9, the low-temperature refrigerant pump 12, and the compressor 15 are all electrically connected to the controller.

[0071] By controlling the connection status of the first three-way valve 16, the second three-way valve 17, and the third three-way valve 14, and controlling the operation of the refrigerant pump 2, the high-temperature refrigerant pump 9, the low-temperature refrigerant pump 12, and the compressor 15, the automatic switching of the operating status of the vehicle cascade waste heat refrigeration system can be achieved.

[0072] In this embodiment of the invention, the refrigerant in the high-temperature stage circuit is a first refrigerant, and the refrigerant in the low-temperature stage circuit is a second refrigerant. The boiling point of the first refrigerant is greater than that of the second refrigerant to ensure that the heat in the low-temperature stage circuit can be smoothly transferred to the high-temperature stage circuit, thereby ensuring the stable and reliable operation of the vehicle cascade waste heat refrigeration system.

[0073] In this embodiment, the refrigerant in the waste heat source circuit can be, but is not limited to, water, aqueous alcohol solutions, or aqueous salt solutions.

[0074] Among them, alcohol-based aqueous solutions possess good antifreeze properties, low corrosivity, and good heat transfer performance. Salt-based aqueous solutions offer excellent low-temperature performance, low cost, good environmental friendliness, and high heat capacity. Water has excellent thermophysical properties; its good thermal conductivity facilitates efficient heat transfer in heat exchangers, improving overall heat exchange efficiency. Furthermore, water has low viscosity and low flow resistance, making it easy to transport in pipelines.

[0075] In a specific embodiment, water is selected as the refrigerant in the waste heat source circuit.

[0076] In this embodiment, the waste heat source includes at least one of the electric drive system and the battery system. The electric drive system and the battery system generate heat during operation. The waste heat exchanger 1 is placed outside the electric drive system and the battery system. When water flows through the waste heat exchanger 1, it absorbs the heat from the electric drive system and the battery system, and when it flows through the high-temperature stage steam generator 8 and the low-temperature stage steam generator 11, it transfers the heat to the refrigerant.

[0077] In summary, the vehicle-mounted cascade waste heat refrigeration system in this embodiment of the invention not only achieves the recovery and utilization of waste heat, but also recovers expansion work through the high-temperature stage ejector 10 and the low-temperature stage ejector 13, effectively reducing the power consumption of the compressor 15, improving cycle efficiency, and reducing system energy consumption. Moreover, the vehicle-mounted cascade waste heat refrigeration system can switch between three operating states according to the heat of the waste heat source and the cooling demand of the refrigeration circuit. Through the synergistic effect of the low-temperature stage evaporator 6, the high-temperature stage steam generator 8, and the low-temperature stage steam generator 11, precise matching of the heat of the waste heat source and the cooling demand of the refrigeration circuit is achieved.

[0078] In addition, the vehicle-mounted cascade waste heat refrigeration system in this embodiment of the invention significantly improves the waste heat refrigeration temperature range by constructing a dual-temperature zone coupled refrigeration cycle architecture. This effectively solves the technical bottleneck of traditional injection refrigeration systems under wide temperature range and large temperature span conditions, and achieves efficient refrigeration under conditions of high condensing temperature and suitable evaporation temperature. It meets the refrigeration needs of automobiles in high-temperature environments, significantly enhances the system's adaptability to operating conditions and operational stability, and can meet the needs of new energy vehicles in all regions.

[0079] On the other hand, embodiments of the present invention also provide a vehicle including the vehicle-mounted cascade waste heat cooling system provided in any of the above embodiments. The vehicle-mounted cascade waste heat cooling system provided in any of the above embodiments can recover and utilize heat from waste heat sources, effectively avoiding energy waste. Therefore, the vehicle in this embodiment has the advantages of low energy consumption and high operational stability and reliability. The derivation process of the beneficial effects of the vehicle in the embodiments of the present invention is largely similar to the derivation process of the beneficial effects of the above-mentioned vehicle-mounted cascade waste heat cooling system, and therefore will not be repeated here.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cascade waste heat refrigeration system for vehicles, characterized in that, include: The waste heat source circuit is suitable for supplying refrigerant circulation. The waste heat source circuit includes a waste heat exchanger (1) and a refrigerant pump (2). The waste heat exchanger (1) is suitable for supplying refrigerant to exchange heat with the waste heat source, and the refrigerant pump (2) is suitable for driving the refrigerant to circulate. The refrigeration circuit includes a high-temperature stage circuit, an interstage heat exchanger (3), and a low-temperature stage circuit. The high-temperature stage circuit includes a high-temperature stage booster, a high-temperature stage condenser (4), and a high-temperature stage expansion valve (5). The refrigerant passage of the high-temperature stage booster, the refrigerant passage of the high-temperature stage condenser (4), the high-temperature stage expansion valve (5), and the first refrigerant passage of the interstage heat exchanger (3) are connected. The low-temperature stage circuit includes a low-temperature stage booster, a low-temperature stage evaporator (6), and a low-temperature stage expansion valve (7). The refrigerant passage of the low-temperature stage booster, the second refrigerant passage of the interstage heat exchanger (3), the low-temperature stage expansion valve (7), and the refrigerant passage of the low-temperature stage evaporator (6) are connected. At least one of the high-temperature stage booster device and the low-temperature stage booster device is adapted to increase the pressure of the refrigerant in the refrigeration circuit by utilizing the heat of the refrigerant in the waste heat exchanger (1).

2. The vehicle-mounted cascade waste heat refrigeration system according to claim 1, characterized in that, The high-temperature stage booster device includes: A high-temperature steam generator (8) has a refrigerant channel connected to the refrigerant pump (2) and the waste heat exchanger (1). A high-temperature refrigerant pump (9) is provided. The inlet of the high-temperature refrigerant pump (9) and the high-temperature expansion valve (5) are both connected to the refrigerant passage of the high-temperature condenser (4). The outlet of the high-temperature refrigerant pump (9) is connected to the refrigerant passage of the high-temperature steam generator (8). The high-temperature stage ejector (10) has its main inlet connected to the refrigerant channel of the high-temperature stage steam generator (8), its ejector port connected to the first refrigerant channel of the interstage heat exchanger (3), and its outlet connected to the refrigerant channel of the high-temperature stage condenser (4).

3. The vehicle-mounted cascade waste heat refrigeration system according to claim 2, characterized in that, The cryogenic stage pressurization device includes: A low-temperature steam generator (11) has a refrigerant channel that is connected to the refrigerant pump (2) and the waste heat exchanger (1). The inlet of the low-temperature stage refrigerant pump (12) and the low-temperature stage expansion valve (7) are both connected to the second refrigerant channel of the interstage heat exchanger (3), and the outlet of the low-temperature stage refrigerant pump (12) is connected to the refrigerant channel of the low-temperature stage steam generator (11). The low-temperature stage ejector (13) has its main inlet connected to the refrigerant channel of the low-temperature stage steam generator (11), its ejector port connected to the refrigerant channel of the low-temperature stage evaporator (6), and its outlet connected to the second refrigerant channel of the interstage heat exchanger (3).

4. The vehicle-mounted cascade waste heat refrigeration system according to claim 3, characterized in that, The waste heat source circuit also includes: The inlet of the third three-way valve (14) is connected to one end of the refrigerant channel of the high-temperature steam generator (8), and the other end of the refrigerant channel of the high-temperature steam generator (8) is connected to the refrigerant pump (2). The second outlet of the third three-way valve (14) is connected to one end of the refrigerant channel of the low-temperature steam generator (11). The other end of the refrigerant channel of the low-temperature steam generator (11) and the first outlet of the third three-way valve (14) are both connected to the refrigerant channel of the waste heat exchanger (1). The inlet of the third three-way valve (14) can be selectively connected to one of the first outlet and the second outlet of the third three-way valve (14).

5. The vehicle-mounted cascade waste heat refrigeration system according to claim 4, characterized in that, The cryogenic stage pressurization device also includes: Compressor (15); The first three-way valve (16) has its inlet connected to the exhaust port of the compressor (15), and its first outlet and the outlet of the cryogenic stage ejector (13) are both connected to the second refrigerant passage of the interstage heat exchanger (3). The inlet of the first three-way valve (16) may be selectively connected to one of the first outlet and the second outlet of the first three-way valve (16). The inlet of the second three-way valve (17) is connected to the refrigerant passage of the low-temperature evaporator (6), the first outlet of the second three-way valve (17) is connected to the suction port of the compressor (15), the second outlet of the first three-way valve (16) and the second outlet of the second three-way valve (17) are both connected to the ejector port of the low-temperature ejector (13), and the inlet of the second three-way valve (17) can be selectively connected to one of the first outlet and the second outlet of the second three-way valve (17).

6. The vehicle-mounted cascade waste heat refrigeration system according to claim 5, characterized in that, Also includes: The controller is equipped with electric valves, including the first three-way valve (16), the second three-way valve (17), and the third three-way valve (14). The first three-way valve (16), the second three-way valve (17), the third three-way valve (14), the refrigerant pump (2), the high-temperature refrigerant pump (9), the low-temperature refrigerant pump (12), and the compressor (15). All of these are electrically connected to the controller.

7. The vehicle-mounted cascade waste heat refrigeration system according to claim 1, characterized in that, The refrigerant in the high-temperature stage circuit is a first refrigerant, and the refrigerant in the low-temperature stage circuit is a second refrigerant. The boiling point of the first refrigerant is greater than that of the second refrigerant.

8. The vehicle-mounted cascade waste heat refrigeration system according to claim 1, characterized in that, The refrigerant in the waste heat source circuit includes water, aqueous alcohol solutions, or aqueous salt solutions.

9. The vehicle-mounted cascade waste heat refrigeration system according to claim 1, characterized in that, The waste heat source includes at least one of the electric drive system and the battery system.

10. A vehicle, characterized in that, Including the vehicle cascade waste heat refrigeration system as described in any one of claims 1-9.

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