A heating and cooling defrosting system and vehicle

Abstract

This invention relates to a heating and cooling defrosting system and vehicle, belonging to the field of pure electric buses. It utilizes a cooling heat exchange core in the heating and cooling defrost unit to form a refrigerant cold circulation pipeline with the first heat source end of the heat exchanger. The second heat source end of the heat exchanger is located in the air conditioning refrigerant circulation pipeline. The heat exchanger facilitates heat exchange between the refrigerant in the air conditioning refrigerant circulation pipeline and the heating and cooling defrost unit. A heating heat exchange core in the heating and cooling defrost unit forms a refrigerant hot circulation pipeline with the heater, which heats the refrigerant, thus achieving heating for the heating and cooling defrost unit. The heating and cooling defrost system of this invention can separately achieve cooling of the entire vehicle's driver's area and defrosting / defogging of the windshield, replacing direct PTC heating and refrigerant system cooling, avoiding safety accidents such as PTC element explosions and short circuits. The use of a heating heat exchange core instead of a refrigerant evaporation core in the heating and cooling defrost unit prevents refrigerant leakage into the vehicle, improving vehicle safety and comfort.

Description

Technical Field

[0001] This invention relates to a defrosting system and vehicle, belonging to the field of pure electric buses. Background Technology

[0002] Pure electric buses commonly use single-heater defrosters, which employ a built-in PTC heater (automotive heater). Once the PTC heater is energized and heats up, an internal fan blows hot air through ducts from various vents on the dashboard to the windshield for defrosting and defogging. However, this method only provides heat for defrosting and defogging. In spring and autumn, and especially in summer, after the PTC heater defrosts the glass, a large amount of hot air remains inside the bus, making it stuffy and uncomfortable for passengers, leading to numerous complaints. Furthermore, pure electric buses have a high voltage platform, resulting in poor PTC stability, a high failure rate, and potential safety issues such as electrode failure and short circuits.

[0003] To address the issue of poor comfort with single-heater defrosters, some high-end pure electric buses have added a refrigerant evaporation heat exchange core and expansion valve inside the vehicle. This connects to the vehicle's pre-installed air conditioning interface to achieve cooling functionality. In spring and autumn, and especially in summer, the cooled, dry air is used for defogging, and the air is then heated by a PTC heater for dehumidification. Cooling can also be used independently to improve the cooling effect in the driver's area, enhancing driver comfort. However, pure electric buses have a high voltage platform, and the PTC heaters have poor stability and a high failure rate, making them prone to safety issues such as coil explosions and short circuits. Furthermore, there is a risk of refrigerant leakage when high-pressure refrigerant enters the driver's cab. Summary of the Invention

[0004] The purpose of this invention is to provide a hot and cold defrosting system and vehicle to solve the problem of poor safety caused by using PTC heaters for defrosting in electric buses.

[0005] To achieve the above objectives, the present invention includes:

[0006] The present invention provides a hot and cold defrosting system, including a hot and cold defrosting device, the hot and cold defrosting device including a housing, in which an airflow channel is formed; the downstream end of the airflow channel is connected to the front air outlet, and the upstream end is used for air intake; a cooling heat exchange core and a heating heat exchange core are provided in the airflow channel;

[0007] The cooling heat exchange core and the first heat source exchange end of the heat exchanger form a cold circulation of heat exchange medium; the second heat source exchange end of the heat exchanger is set in the refrigerant circulation loop of the air conditioner to realize heat exchange between the refrigerant and the heat exchange medium in the heat exchanger; the heating heat exchange core and the heater form a hot circulation of heat exchange medium, and the heater is used to heat the heat exchange medium.

[0008] The cold and warm defrosting system provided by the present invention utilizes the cooling heat exchange core in the cold and warm defrost unit and the first heat source end of the heat exchanger to form a refrigerant cold circulation pipeline, and the second heat source end of the heat exchanger is set in the air conditioner refrigerant circulation pipeline. The heat exchanger is used to realize heat exchange of refrigerant between the air conditioner refrigerant circulation pipeline and the cold and warm defrost unit. The heating heat exchange core in the cold and warm defrost unit and the heater form a refrigerant hot circulation pipeline. The heater is used to heat the refrigerant, thereby realizing the heating of the cold and warm defrost unit.

[0009] The heating and cooling defrosting system of this invention can separately cool the driver's area and defrost and defog the windshield, replacing direct PTC heating and refrigerant system cooling, thus avoiding safety accidents such as PTC chip explosion and short circuits. The heating and cooling defrost unit uses a heating heat exchange core instead of a refrigerant evaporation core, preventing refrigerant leakage into the vehicle and improving vehicle safety and comfort.

[0010] Furthermore, the refrigerant circulation loop includes a compressor, a condenser, an expansion valve, and an evaporator for exchanging heat with the airflow entering the vehicle; the pipeline where the evaporator is located is connected in parallel with the pipeline where the second heat source exchange end is located to form a parallel pipeline;

[0011] When the ambient temperature is higher than the set upper limit, the refrigerant circulation loop works in the cooling state, so that the refrigerant absorbs heat through the evaporator and the second heat source exchange terminal at the same time, and cools the airflow through the cold and warm defrost device by the heat exchange medium cold circulation and the cooling heat exchange core.

[0012] When the ambient temperature is lower than the set value and there is a need for defrosting and defogging, the refrigerant circulation loop operates in a cooling state, allowing the refrigerant to absorb heat through the second heat source exchange end, and to condense and dehumidify the airflow passing through the cold and warm defrost unit through the cold circulation of the heat exchange medium and the cooling heat exchange core. At the same time, the heater is started, and the airflow passing through the cold and warm defrost unit is heated through the hot circulation of the heat exchange medium.

[0013] When the ambient temperature exceeds the set upper limit (i.e., in hot weather), the air conditioning refrigerant circulation system is activated for cooling. Simultaneously, the hot and cold defrost system cools the airflow through its cooling heat exchange core, thus cooling the air entering the vehicle and blowing onto the windshield, increasing the cooling effect. The cooled air, having undergone condensation, is drier and has lower moisture content, which helps defog the windshield. Conversely, when the ambient temperature is below the set value and defrosting / defogging is required (i.e., in cold weather but the windshield needs defrosting / defogging), the corresponding air conditioning refrigerant circulation system activates for heating. The hot and cold defrost system uses its cooling heat exchange core to condense the air passing through it, ensuring its dryness. Then, its heating heat exchange core heats this air before it is blown onto the windshield for defrosting and defogging. This invention's hot and cold defrost system can select different operating modes based on actual environmental conditions and passenger needs, improving passenger comfort while reducing vehicle energy consumption.

[0014] Furthermore, the refrigerant circulation loop also includes a reversing device. One end of the parallel pipeline is connected in series with the condenser and then connected to the second port of the reversing device. The other end is connected to the fourth port of the reversing device. The third port of the reversing device is connected to the compressor inlet, and the compressor outlet is connected to the first port of the reversing device.

[0015] When the vehicle has a heating requirement and the ambient temperature is higher than the set lower limit, the first port and the fourth port of the reversing device are connected, and the second port and the third port are connected, so that the refrigerant circulation loop works in heat pump mode, and the refrigerant vapor condenses and releases heat in the evaporator and in the second heat source exchange terminal.

[0016] The reversing device of this invention employs a four-way reversing valve, which controls the refrigerant flow direction, allowing the vehicle to operate in different modes. When the vehicle requires heating and the ambient temperature is above a set lower limit, the air conditioning refrigerant circulation pipeline operates in heat pump mode. Simultaneously, the refrigerant releases heat in the plate heat exchanger, causing the refrigerant in the hot and cold defrost unit to exchange heat within the plate heat exchanger. After heat exchange, the heat is transferred to the heating heat exchange core, enabling the hot and cold defrost unit to generate heat. By utilizing the air conditioning heat pump to provide heat to the hot and cold defrost unit, the heating efficiency of the hot and cold defrost unit is improved, reducing the overall vehicle energy consumption.

[0017] Furthermore, the method to make the refrigerant circulation loop work in the refrigeration state is to control the first port of the commutation device to connect with the second port and the third port to the fourth port.

[0018] Furthermore, a vehicle compartment radiator is connected in parallel on the pipeline where the heater is located, and the vehicle compartment radiator is used to exchange heat with the airflow entering the vehicle.

[0019] When the vehicle has a heating requirement and the ambient temperature is below the set lower limit, the heater is activated. The airflow passing through the defrost unit is heated through the heat exchange medium heat circulation, and the airflow entering the vehicle is also heated through the radiator.

[0020] When the vehicle requires heating and the ambient temperature is below a set lower limit, the heater heats the refrigerant, enabling the defroster to heat up while simultaneously heating the passenger compartment radiator. By combining a heater and an air conditioning heat pump to heat various components of the vehicle, multiple methods can be used to achieve heating for the defroster, ensuring effective defrosting and defogging of the windshield.

[0021] Furthermore, a first expansion valve is connected in series on the side of the evaporator connecting to the condenser on the pipeline where the evaporator is located, and a second expansion valve is connected in series on the side of the second heat source exchange terminal connecting to the condenser on the pipeline where the second heat source exchange terminal is located; the first expansion valve and the evaporator are also connected to the end of the pipeline where the second heat source exchange terminal is located near the second expansion valve through a first bypass; the end of the pipeline where the second heat source exchange terminal is located away from the second expansion valve is connected to the third port of the reversing device through a second bypass.

[0022] When the vehicle requires both heating and defrosting / defogging, the first and fourth ports of the reversing device are connected, as well as the second and third ports, to enable the refrigerant circulation loop to operate in heat pump mode. By controlling the shut-off valves on the corresponding pipelines, the refrigerant vapor from the compressor first condenses and releases heat through the evaporator. After releasing heat, the refrigerant returns to the compressor after evaporating and absorbing heat in the condenser through the first expansion valve. The other path passes through the first bypass and the second expansion valve, where it condenses and absorbs heat at the second heat source exchange end before returning to the compressor through the second bypass.

[0023] When the vehicle requires both heating and defrosting / defogging, the air conditioning refrigerant circulation loop operates in heat pump mode. Simultaneously, the refrigerant releases heat in the plate heat exchanger, allowing the refrigerant in the hot and cold defrost system to exchange heat within the plate heat exchanger. Then, the refrigerant released heat by the air conditioning system in heat pump mode and the refrigerant exchanged heat in the plate heat exchanger return to the compressor through a four-way reversing valve. By using a combination of heaters and an air conditioning heat pump to heat various components of the vehicle, multiple methods can be used to achieve heating in the hot and cold defrost system, ensuring effective defrosting and defogging of the windshield.

[0024] Furthermore, the hot and cold defrost unit has a drain outlet at the lowest point inside the housing.

[0025] When a defrosting unit uses a cooling heat exchange core for cooling, it produces condensate. Therefore, the condensate is drained from the casing through a drain outlet.

[0026] Furthermore, the hot and cold defrost unit is provided with a damper upstream of the airflow channel for switching between internal and external air intake.

[0027] By using dampers to adjust the ratio of internal and external air intake, the structure of solely external or solely internal air intake can be avoided. The damper opening degree can be adjusted according to actual needs to achieve different ratios of fresh air mixing.

[0028] Furthermore, the branch where the heater is located is connected to the branch where the heating heat exchange core is located and the branch where the radiator of the carriage is located via a three-way proportional regulating valve.

[0029] The proportion of refrigerant entering the defrosting unit and radiator can be adjusted using a three-way proportional control valve.

[0030] The present invention also provides a vehicle that includes the above-described heating and cooling defrosting system. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the first part of the cold and warm defrosting device of the present invention;

[0032] Figure 2 This is a schematic diagram of the second part of the cold and warm defrosting device of the present invention;

[0033] Figure 3 This is a schematic diagram of the heat exchange core structure of the cold and warm defrosting device of the present invention;

[0034] Figure 4 This is a schematic diagram of the passenger vehicle defrosting system of the present invention;

[0035] Figure 5 This is a schematic diagram of the working process of Mode 1 of the present invention;

[0036] Figure 6 This is a schematic diagram of the working process of Mode 2 of the present invention;

[0037] Figure 7 This is a schematic diagram of the working process of Mode 3 of the present invention;

[0038] Figure 8 This is a schematic diagram of the working process of Mode 4 of the present invention;

[0039] Figure 9 This is a schematic diagram of the working process of Mode 5 of the present invention. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings.

[0041] System Implementation Example:

[0042] This invention provides a novel heating and cooling defrosting system for buses. This system eliminates the need for a built-in high-pressure PTC heater in the defroster, avoiding the problems of poor PTC stability and high failure rate, and further preventing safety issues such as PTC heater failure and short circuits. Furthermore, it eliminates the need for an air conditioning refrigerant evaporator core, preventing the safety risk of high-pressure refrigerant entering the driver's cab and causing leakage.

[0043] Specifically, such as Figure 1 , Figure 2 The diagram shown is a schematic of the structure of the cold and warm defrost device of the present invention, including a cold and warm defrost device air outlet 21, a defrost device shell 22, a fan 23, a heat exchange core (for heating) 24, a heat exchange core (for cooling) 25, an air inlet damper 26, an air inlet inside the defrost device 27, an air inlet outside the defrost device 28, a drain pipe 29, and an air inlet damper position adjustment motor 20.

[0044] The defrost outlet 21 connects to the air outlet on the windshield of the dashboard, delivering the air processed by the defrost to the vehicle interior for defrosting and defogging the windshield. The fan 23 is a flow-through turbine fan with a brushless motor, offering lower noise and a longer lifespan compared to brushed motors. The heat exchange core (for heating) 24 uses an aluminum strip structure to provide heating energy to the defrost. The heated coolant passes through the heat exchange core (for heating) and transfers its heat to the air inside the defrost, achieving heating. The heat exchange core (for cooling) 25 also uses an aluminum strip structure to provide cooling energy to the defrost. The cooled coolant passes through the heat exchange core (for cooling) and transfers its cooling energy to the air inside the defrost, achieving cooling. The air inlet damper 26 is used for air intake in the defrost. The defrost unit's interior air inlet 27 connects to the interior of the vehicle compartment, drawing air from inside. The air inside the compartment is clean and has a relatively small temperature difference compared to the air outlet. The exterior air inlet 28 connects to the outside of the vehicle compartment, drawing air from outside. In winter, the outside air has low humidity, making it suitable for defrosting and defogging, and it is also fresher, increasing the oxygen content inside the compartment. However, in areas with high winds, sand, and dust, the air cleanliness is poor, requiring a filter to be installed at the air inlet. Both the interior and exterior air inlets 27 and 28 are used to switch the defrost unit's air intake mode. Adjusting the position and angle of the air inlets moves the motor, which in turn rotates the damper to create different proportions of mixed interior and exterior air. The drain pipe 20 is used when refrigeration is in operation; condensate will form on the surface of the refrigeration heat exchange core, which is drained from the heating and cooling defrost unit. A represents the heating water inlet / outlet, and b represents the refrigeration water inlet / outlet.

[0045] The heat exchange core (for heating) 24 and the heat exchange core (for cooling) 25 adopt the same core structure, as detailed below. Figure 3As shown, the device includes water chambers 31, 32, and 33, inlet and outlet 34, baffle 35, heat dissipation fins 36, and a water-passing flat tube 37. The baffle 35 divides the cavity connected to the inlet and outlet 34 into water chambers 31 and 32. Coolant enters the water-passing flat tube 37 through water chambers 31 or 32 to exchange heat with the air. The heat dissipation fins 36 are brazed to both sides of the water-passing flat tube 37 to increase the heat exchange effect between the coolant and the air. After passing through water chamber 33, the coolant returns and exchanges heat again through the water-passing flat tube 37 before flowing out of the heat exchange core. The coolant used in this invention is a mixture of ethylene glycol and water; other coolants can also be used.

[0046] The passenger vehicle cooling and heating defrosting system of the present invention utilizes a cooling and heating defroster connected to the vehicle's air conditioning system and heating system to realize the functions of cooling, heating, defrosting, and defogging of the cooling and heating defroster, avoiding various safety problems that are easily caused by the use of PTC heaters in existing defrosters.

[0047] like Figure 4 The image shows the passenger vehicle cooling and defrosting system proposed in this invention, including an air conditioning compressor 1, a four-way reversing valve 2, a gas-liquid separator 3, a condenser 4, a first electronic expansion valve 5, a passenger compartment evaporator 6, a first solenoid valve 7, a second solenoid valve 8, a third solenoid valve 9, a fourth solenoid valve 10, a second electronic expansion valve 11, a plate heat exchanger 12, a water pump 13, a cooling and defrosting device 14, a water pump 15, a liquid heater 16, a three-way proportional regulating valve 17, and a passenger compartment radiator 18.

[0048] During the cooling process in the passenger compartment, the air conditioning compressor 1 compresses high-temperature and high-pressure refrigerant gas. The refrigerant gas passes through the four-way reversing valve 2 and enters the condenser 4. After passing through the condenser 4, the refrigerant gas liquefies into refrigerant liquid. The refrigerant liquid flows into the evaporator 6 through the first electronic expansion valve 5. The refrigerant liquid needs to absorb heat to vaporize into refrigerant gas, thereby removing the heat from the passenger compartment. The refrigerant gas formed after the refrigerant vaporizes passes through the four-way reversing valve 2 and enters the gas-liquid separator 3. After the gas-liquid separator 3 separates the refrigerant gas and refrigerant liquid, the air conditioning compressor 1 draws refrigerant gas for a new round of compression.

[0049] During the defrosting process, the air conditioning compressor 1 compresses high-temperature, high-pressure refrigerant gas. This gas passes through a four-way reversing valve 2 and enters the condenser 4. After passing through the condenser 4, the refrigerant gas liquefies into liquid refrigerant. The liquid refrigerant then passes through a first solenoid valve 7 and a second electronic expansion valve 11 to reach the plate heat exchanger 12. The plate heat exchanger continuously absorbs heat, vaporizing the liquid refrigerant back into gas. The vaporized refrigerant gas then passes through the four-way reversing valve 2 and enters the gas-liquid separator 3. The gas-liquid separator 3 separates the gas and liquid refrigerant, after which the air conditioning compressor 1 draws in the gas refrigerant for a new round of compression. The heat absorbed by the plate heat exchanger 12 comes from the coolant in the heating and cooling defrost unit. The coolant in the heating and cooling defrost unit continuously provides heat to the plate heat exchanger, causing its temperature to drop. The cooled coolant is then driven by a water pump 13 to provide cooled refrigerant to the heat exchange core (for refrigeration) within the heating and cooling defrost unit 14 for cooling.

[0050] During the heat pump heating process in the vehicle compartment, the air conditioning compressor 1 compresses high-temperature and high-pressure refrigerant gas. The refrigerant gas passes through the four-way reversing valve 2 and enters the evaporator 6. In the evaporator 6, the refrigerant gas liquefies into refrigerant liquid. During the liquefaction process, a large amount of heat is released, thereby achieving the heating effect. The refrigerant liquid formed after liquefaction passes through the first electronic expansion valve 5 and enters the condenser 4. The condenser 4 absorbs heat and causes the refrigerant liquid to vaporize into refrigerant gas. The refrigerant gas passes through the four-way reversing valve 2 and enters the gas-liquid separator 3. After the gas-liquid separator 3 separates the refrigerant gas and refrigerant liquid, the air conditioning compressor 1 draws refrigerant gas for a new round of compression.

[0051] The passenger compartment radiator 18 includes a driver heater, a passenger area radiator, and a passenger door sill heater. Utilizing the high-voltage electricity from the vehicle's power battery, the coolant is heated by a liquid heater 16 during the radiator's heating process. Power is provided by a water pump 15, and the heated coolant, passing through the liquid heater 16, then through a three-way proportional control valve 17, reaches the passenger compartment radiator 18, providing high-temperature refrigerant for heating the passenger compartment. The liquid heater 16 in this invention can be a PTC liquid heater or a fuel-fired heater.

[0052] During the heating process of the heat pump in the defrosting system, the air conditioner compressor 1 compresses high-temperature, high-pressure refrigerant gas. This gas passes through a four-way reversing valve 2 and a third solenoid valve 9 before entering the plate heat exchanger 12. Within the plate heat exchanger 12, the refrigerant gas liquefies into liquid refrigerant, releasing a large amount of heat during this process. The liquefied liquid refrigerant then passes through a second electronic expansion valve 11 and a first solenoid valve 7 before entering the condenser 4. In the condenser 4, the liquid refrigerant absorbs heat and vaporizes back into gas. This gas then passes through the four-way reversing valve 2 into the gas-liquid separator 3. After the gas-liquid separator 3 separates the gas and liquid refrigerant, the air conditioner compressor 1 draws in the gas refrigerant for a new round of compression. The large amount of heat released during the liquefaction process in the plate heat exchanger 12 heats the refrigerant in the defrosting system. The heated refrigerant is then pumped by a water pump 13 to supply the heat exchange core (for heating) within the defrosting system 14.

[0053] In the process of using a liquid heater to heat the refrigerant to enable the heat pump of the defrost unit, the high voltage of the vehicle's power battery is used to power the water pump 15. The refrigerant is heated by the liquid heater 16, and the heated refrigerant is supplied to the heat exchange core (for heating) in the defrost unit 14 through the three-way proportional regulating valve 17.

[0054] Based on the various cooling and heating conditions described above, and according to the different needs for defrosting, defogging, and heating based on the vehicle's external ambient temperature, the following centralized operating modes are defined:

[0055] Mode 1: During hot summer weather, the entire vehicle needs rapid cooling. In addition to air conditioning, a heating and cooling defrost system is also required to accelerate the temperature drop in the driver's area. The working process is as follows: Figure 5 As shown, when the air conditioner and the defrosting system receive a cooling demand, the first electronic expansion valve 5, the second electronic expansion valve 11, the first solenoid valve 7, and the third solenoid valve 9 are opened, while the second solenoid valve 8 and the fourth solenoid valve 10 are closed. Simultaneously, the air conditioner performs its own cooling process, while the defrosting system performs its own cooling process. Heat is removed from the passenger compartment through the air conditioner evaporator, and the defrosting system, driven by the water pump 13, exchanges heat with the refrigerant in the plate heat exchanger 12, removing heat from within the defrosting system. The first electronic expansion valve 5 and the second electronic expansion valve 11 are independent and can operate individually or simultaneously. They are complementary and coupled, meaning the air conditioner and the defrosting system can operate independently or simultaneously.

[0056] Mode Two: In spring and autumn, when humidity is high in the mornings and evenings, or on rainy days, the vehicle's windshield is prone to fogging. Since the vehicle doesn't need air conditioning for cooling, a hot and cold defroster is required to remove the fog from the windshield surface. Therefore, a hot and cold defroster is necessary. The working process is as follows... Figure 6 As shown, the first electronic expansion valve 5 is closed, the first solenoid valve 7 and the third solenoid valve 9 are opened, and the second solenoid valve 8 and the fourth solenoid valve 10 are closed. The refrigerant circulates to provide cooling to the plate heat exchanger 12, and the water pump 13 operates to provide cooling refrigerant to the heat exchange core (for refrigeration) in the heating and cooling defrost unit 14. This creates a cold circulation of heat exchange medium between the heat exchange core (for refrigeration) and the plate heat exchanger. In addition, the water pump 15 and the liquid heater 16 operate, and the three-way proportional regulating valve 17 is opened to provide heated refrigerant to the heat exchange core (for heating) in the heating and cooling defrost unit 14. At this time, both the heat exchange core (for refrigeration) and the heat exchange core (for heating) of the heating and cooling defrost unit operate simultaneously. Air enters the heating and cooling defrost unit through the damper, first passing through the heat exchange core (for refrigeration) for cooling and condensation to remove moisture, ensuring dry air. The moisture removed from the air is discharged from the heating and cooling defrost unit through the drain pipe. The cooled and dried air is then heated by the heat exchange core (for heating), and the dry hot air is blown out of the air outlet of the hot and cold defrost unit to defog the windshield.

[0057] Mode 3: When the vehicle is in an ambient temperature ≥ -5℃, the heat pump heating is more energy-efficient than the liquid heater heating at this temperature. To save overall vehicle energy consumption, increase vehicle range, and reduce customer operating costs, the vehicle uses the heat pump for heating. The working process is as follows: Figure 7 As shown, the first electronic expansion valve 5, the second electronic expansion valve 11, the first solenoid valve 7, and the third solenoid valve 9 are opened, while the second solenoid valve 8 and the fourth solenoid valve 10 are closed. The high-temperature, high-pressure refrigerant gas compressed by the compressor releases heat through the evaporator 6 and the plate heat exchanger 12. The evaporator 6 exchanges heat with the air inside the vehicle compartment to raise the temperature inside the compartment. The water pump 13 operates, and the defrosting unit 14, driven by the water pump 13, performs heat exchange with the refrigerant in the plate heat exchanger 12. This provides heated refrigerant to the heat exchange core (for heating) within the defrosting unit 14 for heating, thus forming a heat exchange medium thermal cycle between the heat exchange core (for heating) and the plate heat exchanger.

[0058] Mode 4: When the ambient temperature is below -5℃, the heat pump heating is less efficient than the liquid heater heating at this temperature. To save energy, the vehicle uses the liquid heater for heating, and the air conditioning compressor does not operate. The working process is as follows: Figure 8 As shown, the water pump 15 is working, and the liquid heater 16 heats the refrigerant. The heated refrigerant flows through the three-way proportional regulating valve 17 into the heat exchange core (for heating) in the radiator 18 and the defrost unit 14. The heat is then transferred to the vehicle interior through the radiator 18 and the defrost unit 14 to provide warmth for passengers and defrost the windshield.

[0059] Mode 5: During the spring and autumn rainy seasons, when the weather is cold in the mornings and evenings and there are many passengers in the carriage, resulting in high humidity, the carriage needs heating, but the windshield needs dry air for defogging. The working process is as follows: Figure 9 As shown, the first electronic expansion valve 5 and the second electronic expansion valve 11 are open, the first solenoid valve 7 and the third solenoid valve 9 are closed, and the second solenoid valve 8 and the fourth solenoid valve 10 are open. The high-temperature and high-pressure refrigerant gas compressed by the air conditioning compressor 1 is liquefied into refrigerant liquid after being cooled by the evaporator 6. Part of the refrigerant liquid is vaporized and absorbs heat through the condenser 4 to form refrigerant gas, which flows back to the four-way reversing valve 2. The other part of the refrigerant liquid flows into the plate heat exchanger 12 through the second solenoid valve 8. After absorbing heat and vaporizing into refrigerant gas in the plate heat exchanger 12, it merges with the first part of the refrigerant gas through the fourth solenoid valve 10 and flows back to the gas-liquid separator 3 through the four-way reversing valve 2. In the defrosting circuit 14, the refrigerant releases heat in the plate heat exchanger 12, thus lowering its temperature. The cooled refrigerant, driven by the water pump 13, flows into the heat exchange core (for refrigeration) of the defrosting circuit 14, forming a cold circulation of heat exchange medium between the heat exchange core (for refrigeration) and the plate heat exchanger. Air enters the defrosting circuit through a damper, passes through the heat exchange core (for refrigeration), is cooled, and condenses to remove moisture, ensuring dry air. The condensed moisture is discharged from the defrosting circuit through a drain pipe. The operation of the liquid heater is controlled based on the indoor temperature to improve heating in the vehicle compartment and the outlet air temperature of the defrosting circuit.

[0060] This invention provides a hot and cold defrost unit and system for passenger vehicles. The hot and cold defrost unit uses refrigerant heat exchange instead of a PTC heater and refrigerant cooling, improving vehicle safety and comfort, and enhancing component reliability. In the hot and cold defrost system, the cooling and heating functions of the passenger air conditioning and the hot and cold defrost unit are designed separately, enabling the fulfillment of different functional requirements of the vehicle while saving system installation space and cost. Furthermore, the combination of a heater and a heat pump air conditioning system heats various parts of the vehicle, enabling defrosting and defogging of the windshield through multiple methods.

[0061] Vehicle Example:

[0062] The present invention provides a vehicle that adopts the above-mentioned hot and cold defrosting system. The hot and cold defrosting system has been clearly described in the system embodiments and will not be repeated here.

Claims

1. A hot and cold defrosting system, characterized in that, The device includes a cooling and heating defrosting unit, which includes a housing and an airflow channel formed within the housing. The downstream end of the airflow channel is connected to the front air outlet, and the upstream end is used for air intake. A cooling heat exchange core and a heating heat exchange core are provided in the airflow channel. The cooling heat exchange core and the first heat source exchange end of the heat exchanger form a cold circulation of heat exchange medium; the second heat source exchange end of the heat exchanger is set in the refrigerant circulation loop of the air conditioner to realize heat exchange between the refrigerant and the heat exchange medium in the heat exchanger; the heating heat exchange core and the heater form a hot circulation of heat exchange medium, and the heater is used to heat the heat exchange medium. The refrigerant circulation loop includes a compressor, a condenser, an expansion valve, and an evaporator for exchanging heat with the airflow entering the vehicle; the pipeline where the evaporator is located is connected in parallel with the pipeline where the second heat source exchange end is located to form a parallel pipeline; When the ambient temperature is higher than the set upper limit, the refrigerant circulation loop works in the cooling state, so that the refrigerant absorbs heat through the evaporator and the second heat source exchange terminal at the same time, and cools the airflow through the cold and warm defrost device by the heat exchange medium cold circulation and the cooling heat exchange core. When the ambient temperature is lower than the set value and there is a need for defrosting and defogging, the refrigerant circulation loop operates in a cooling state, allowing the refrigerant to absorb heat through the second heat source exchange end, and to condense and dehumidify the airflow passing through the cold and warm defrost unit through the cold circulation of the heat exchange medium and the cooling heat exchange core. At the same time, the heater is started, and the airflow passing through the cold and warm defrost unit is heated through the hot circulation of the heat exchange medium.

2. The defrosting system according to claim 1, characterized in that, The refrigerant circulation loop also includes a reversing device. One end of the parallel pipeline is connected in series with the condenser and then connected to the second port of the reversing device. The other end is connected to the fourth port of the reversing device. The third port of the reversing device is connected to the compressor inlet, and the compressor outlet is connected to the first port of the reversing device. When the vehicle has a heating requirement and the ambient temperature is higher than the set lower limit, the first port and the fourth port of the reversing device are connected, and the second port and the third port are connected, so that the refrigerant circulation loop works in heat pump mode, and the refrigerant vapor condenses and releases heat in the evaporator and in the second heat source exchange terminal.

3. The defrosting system according to claim 2, characterized in that, The method to make the refrigerant circulation loop work in the refrigeration state is to control the first port and the second port of the commutation device to be connected, and the third port and the fourth port to be connected.

4. The defrosting system according to claim 3, characterized in that, The heater is also connected in parallel to a vehicle compartment radiator, which is used to exchange heat with the airflow entering the vehicle. When the vehicle has a heating requirement and the ambient temperature is below the set lower limit, the heater is activated. The airflow passing through the defrost unit is heated through the heat exchange medium heat circulation, and the airflow entering the vehicle is also heated through the radiator.

5. The defrosting system according to claim 4, characterized in that, A first expansion valve is connected in series on the side of the evaporator connected to the condenser on the pipeline where the evaporator is located. A second expansion valve is also connected in series on the side of the second heat source exchange terminal connected to the condenser on the pipeline where the second heat source exchange terminal is located. The first expansion valve is connected to the evaporator and the end of the pipeline where the second heat source exchange terminal is located near the second expansion valve through a first bypass. The end of the pipeline where the second heat source exchange terminal is located away from the second expansion valve is connected to the third port of the reversing device through a second bypass. When the vehicle requires both heating and defrosting / defogging, the first and fourth ports of the reversing device are connected, as well as the second and third ports, to enable the refrigerant circulation loop to operate in heat pump mode. By controlling the shut-off valves on the corresponding pipelines, the refrigerant vapor from the compressor first condenses and releases heat through the evaporator. After releasing heat, the refrigerant returns to the compressor after evaporating and absorbing heat in the condenser through the first expansion valve. The other path passes through the first bypass and the second expansion valve, where it condenses and absorbs heat at the second heat source exchange end before returning to the compressor through the second bypass.

6. The defrosting system according to claim 5, characterized in that, The hot and cold defrost unit has a drain outlet located at the lowest point inside the housing.

7. The defrosting system according to claim 6, characterized in that, The hot and cold defrost unit has an air damper upstream of the airflow channel for switching between internal and external air intake.

8. The defrosting system according to claim 7, characterized in that, The branch containing the heater is connected to the branch containing the heating heat exchange core and the branch containing the radiator in the carriage via a three-way proportional regulating valve.

9. A vehicle, characterized in that, Includes a hot and cold defrosting system as described in any one of claims 1-8.

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