EV Heat Pump HVAC Assembly for Continuous Heating During Defrost
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Solution Overview
Problem
Conventional heat pump air conditioners for electric vehicles face inefficiencies in defrosting processes, leading to slow defrosting and lack of heat supplementation during defrosting, resulting in reduced interior temperatures and poor ride comfort.
Innovation Solution
A heat pump air conditioner assembly for electric vehicles, incorporating a four-way valve system, an auxiliary heater, and a defrosting electromagnetic valve, which allows for continuous heating during defrosting by routing refrigerant through the outside-vehicle heat exchanger and using an auxiliary heater to maintain interior warmth, while accelerating the defrosting process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the outside-vehicle heat exchanger is used as an evaporator for refrigeration, then refrigeration function is achieved, but the heat exchanger frosts easily and heat exchange efficiency is greatly reduced
Solution Approach 1:
The patent implements preliminary defrosting action by using the inside-vehicle heat exchanger as a defrosting heat source before the outside-vehicle heat exchanger can frost severely. The system switches to defrosting mode when frost is detected, using hot refrigerant from the inside-vehicle heat exchanger to melt frost on the outside-vehicle heat exchanger proactively, preventing severe frosting that would reduce heat exchange efficiency.
2Reliability
If the conventional heat pump air conditioner operates in refrigeration cycle during defrosting, then the outside-vehicle heat exchanger can be defrosted, but no heat is supplied to the vehicle interior and temperature drops significantly
Solution Approach 1:
The inside-vehicle heat exchanger serves dual functions: it acts as an evaporator during refrigeration mode and as a defrosting heat source during defrosting mode. This multi-functionality allows the system to provide both defrosting capability and continuous heating to the vehicle interior, eliminating the need to switch to pure refrigeration cycle for defrosting.
Solution Approach 2:
The patent ensures continuous heating action to the vehicle interior during defrosting by maintaining the inside-vehicle heat exchanger in heating mode while using its hot refrigerant to defrost the outside-vehicle heat exchanger. This continuity of useful heating action prevents temperature drops and maintains comfort during the defrosting process.
3Reliability
If the defrosting process is implemented using conventional refrigeration cycle, then the outside-vehicle heat exchanger can be defrosted, but the defrosting speed is slow and there is no heat supplement
Solution Approach 1:
The patent converts the heat that would normally be wasted in the refrigeration cycle into a beneficial defrosting heat source. By using the hot refrigerant from the inside-vehicle heat exchanger (which would otherwise be used for interior heating) to defrost the outside-vehicle heat exchanger, the system transforms a potentially harmful frosting issue into an opportunity to utilize waste heat, thereby accelerating the defrosting process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures continuous heat supply to the vehicle interior during defrosting, enhancing ride comfort and accelerating the defrosting process by using the auxiliary heater and optimizing refrigerant flow.
Implementation Method 1
the auxiliary heater is turned on
Implementation Method 2
the outside-vehicle heat exchanger and the in-vehicle heat exchanger are connected in series by a fifth pipeline to form a refrigerant loop
Implementation Method 3
When it is necessary to perform refrigeration, an in-vehicle heat exchanger is used as an evaporator. When it is necessary to perform heating, the in-vehicle heat exchanger is used as a condenser by the reversing of the four-way valve
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A heat pump air conditioner assembly for an electric vehicle and a control method thereof, and an electric vehicle with the heat pump air conditioner assembly for the electric vehicle are provided. The heat pump air conditioner assembly includes a heat pump air conditioning system (10) and a Heating, Ventilation and Air Conditioning (HVAC) box body (20). An in-vehicle heat exchanger (15a, 15b) of the heat pump air conditioning system (10) is located in the HVAC box body (20). An auxiliary heater (24) is also arranged in the HVAC box body (20). The auxiliary heater (24) is located at a leeward side of the in-vehicle heat exchanger (15a, 15b). The heat pump air conditioning system (10) is provided with a defrosting branch connecting with a refrigerant outlet of an external heat exchanger (13) and a suction port of a compressor (11). When the heat pump air conditioning system (10) is in a defrosting mode, the HVAC box body (20) supplies air to the vehicle, the auxiliary heater (24) is turned on, and the defrosting branch is turned on. The vehicle heat pump air conditioner assembly can still transfer heat into the vehicle when the heat pump system is defrosting, ensuring a suitable vehicle interior temperature and improving ride comfort. Moreover, the defrosting branch effectively improves defrosting efficiency.