Vehicle Heat Pump Circuit Fluid Redirection
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Solution Overview
Problem
Current motor vehicle air conditioning circuits, especially in heat pump mode, often generate excessive heat energy, leading to discomfort for occupants due to high air temperatures in the passenger compartment, particularly when cooling components like batteries and electric motors.
Innovation Solution
An improved indirect reversible air conditioning circuit with a central control unit that manages the redirection of a heat transfer fluid between internal and external radiators, and adjusts compressor speed to maintain optimal air temperatures, ensuring the air entering the passenger compartment is within comfortable ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the air conditioning circuit operates in heat pump mode to cool external components (batteries, motors), then the cooling capacity for components is improved, but the air temperature in the passenger compartment becomes too hot and comfort deteriorates
Solution Approach 1:
The patent segments the heat transfer fluid circulation into two independent loops: a first loop (internal circuit) that serves the passenger compartment via the internal radiator, and a second loop (external circuit) that cools external components via the external radiator. The control unit independently manages each loop, allowing simultaneous operation with optimized temperature control for both interior comfort and component cooling.
Solution Approach 2:
The control unit dynamically adjusts operational parameters including the flow rates of heat transfer fluid in both loops, compressor speed, and valve positions based on real-time temperature sensors. This enables precise control of heat distribution to maintain passenger compartment temperature within comfortable ranges while providing adequate cooling to external components.
2Productivity
If the heat transfer fluid temperature is increased to improve component cooling, then the cooling efficiency for external components is improved, but the air flow temperature in the passenger compartment becomes too high
Solution Approach 1:
The patent divides the thermal management system into separate internal and external circuits, each with independent flow control. This allows the external circuit to operate at higher temperatures for efficient component cooling while the internal circuit maintains lower temperatures for passenger comfort, eliminating the trade-off between the two functions.
Solution Approach 2:
The control unit continuously monitors temperature parameters and dynamically adjusts the flow rates, compressor speed, and valve positions in real-time. This dynamic control enables the system to optimize cooling efficiency for external components while simultaneously maintaining comfortable temperature levels in the passenger compartment.
3Device complexity
If a single heat transfer fluid loop is used to simplify the circuit architecture, then the device complexity is reduced, but the ability to independently control interior and exterior temperatures is lost
Solution Approach 1:
The patent implements segmentation by creating two independent heat transfer fluid loops with separate control mechanisms. The first loop serves the internal radiator for passenger compartment climate control, while the second loop serves the external radiator for component cooling. This segmentation enables independent temperature control for each function while maintaining a relatively simple overall architecture.
Solution Approach 2:
The dual-loop system provides multi-functionality by enabling the air conditioning circuit to simultaneously perform interior climate control and exterior component cooling. The control unit can independently manage each loop to adapt to various operating conditions, including simultaneous operation, making the system versatile for different thermal management scenarios.
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
The solution effectively manages heat energy distribution, maintaining the average interior air temperature between 40 and 48°C and the evaporator outlet temperature between 2 and 4°C, thereby enhancing passenger compartment comfort and preventing overheating.
Implementation Method 1
a first two-fluid heat exchanger arranged jointly on the first refrigerant fluid loop and on a second heat transfer fluid loop in which a first heat transfer fluid circulates, the first two-fluid heat exchanger being arranged so as to allow heat exchanges between the first refrigerant fluid loop and the second heat transfer fluid loop
Implementation Method 2
an internal radiator arranged parallel to each other... the first heat transfer fluid is redirected only to the internal radiator
Implementation Method 3
an external radiator... the first heat transfer fluid is redirected both to the internal radiator and to the external radiator
Implementation Method 4
a compressor
Implementation Method 5
a first expansion device... a second expansion device
Data Source
Figure 1~9
Figure 3~4
Figure 5~7
AI summary
30 ABSTRACT The present invention relates to a method for managing an indirect reversible air-conditioning circuit (1) for a motor vehicle, comprising a first refrigerant loop (A), wherein a refrigerant circulates and comprising a first dual-fluid heat exchanger (5) arranged together on the first refrigerant loop (A) and on a second heat-transfer fluid loop (B), wherein a first heat-transfer fluid circulates, said circuit being able to operate according to: • a heat pump mode, and • a heat pump dehumidification mode, derived from the heat pump mode, when the indirect air-conditioning circuit (1) is in heat pump mode or heat pump dehumidification mode, a central control unit (90) controls the device for redirecting the first heat-transfer fluid so that: • if the temperature measured at a temperature sensor (72) is greater than or equal to T72t + Y1, the first heat-transfer fluid is redirected both to an internal radiator (54) and to an external radiator (64), • if the temperature measured at the temperature sensor (72) is less than or equal to T72t - Y2, the first heat-transfer fluid is redirected only to the internal radiator (54). FIGURE TO BE INCLUDED IN THE ABSTRACT: Figure 1