Vehicle HVAC Coolant Loop Modulation for Efficient Heat Pump Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Secondary loop heat pump systems in vehicles are less efficient due to indirect heat transfers and lack adaptive control, which limits their energy efficiency and competitiveness with other heating solutions like HV-PTC heaters.
Innovation Solution
A vehicle HVAC system with a refrigerant loop and a coolant loop, featuring modulating manifolds and reservoirs, and a control module that dynamically directs coolant flows through air-to-coolant heat exchangers based on operation mode, enhancing energy efficiency and reducing the need for refrigerant circulation through cabin heat exchangers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a secondary loop heat pump system is used, then safety is improved and refrigerant cost is reduced, but energy efficiency deteriorates due to indirect heat transfers
Solution Approach 1:
The system dynamically switches between secondary loop mode (for safety) and direct refrigerant circulation mode (for efficiency) based on operating conditions. The control module adjusts the system configuration in real-time, allowing the heat pump to operate in different modes including heat pump only, heat pump with auxiliary heater, and direct refrigerant circulation, thereby resolving the contradiction between safety and energy efficiency.
2Adaptability or versatility
If refrigerant valves are added to air-to-air heat pump systems, then control capability is improved, but device complexity and cost increase
Solution Approach 1:
The control module serves multiple functions: it controls refrigerant flow distribution, manages auxiliary heater operation, coordinates heat pump cycling, and adapts to different operating modes. This single multi-functional control unit replaces what would otherwise require multiple specialized valves and control mechanisms, reducing overall system complexity while maintaining comprehensive control capability.
3Use of energy by moving object
If refrigerant is circulated through cabin heat exchangers, then heating and cooling efficiency is improved, but safety risks increase due to potential evaporator breaches
Solution Approach 1:
The system uses an intermediary approach where refrigerant circulates through external heat exchangers (condenser and evaporator) located outside the passenger compartment. Heat transfer occurs through heat exchanger surfaces without direct refrigerant contact with cabin air, eliminating safety risks associated with evaporator breaches while maintaining efficient heat transfer. The refrigerant remains confined to the external loop throughout the 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
The system achieves improved energy efficiency and safety by optimizing coolant flow directions, potentially eliminating the need for HV-PTC heaters, and reducing refrigerant usage and costs, while ensuring effective heating and cooling of the passenger compartment.
Implementation Method 1
a refrigerant loop having first and second refrigerant-to-coolant heat exchangers
Implementation Method 2
a coolant loop having a first reservoir and a first manifold for directing a first flow of coolant through at least one of a plurality of air-to-coolant heat exchangers
Data Source
AI summary
A vehicle having a heating and cooling system includes a refrigerant loop having first and second heat exchangers, a compressor, and an expansion device, and a coolant loop. The coolant loop is connected, in one embodiment, to allow a first flow of coolant to be directed through each of a plurality of heat exchangers and an auxiliary coolant loop and to allow a second flow of coolant to be directed through each of the plurality of heat exchangers and the auxiliary coolant loop dependent upon a mode of operation. A control module controls the first and second flows dependent upon the mode of operation. In one other embodiment, the coolant loop includes manifolds and reservoirs with regulating sending and receiving ports for directing the flows. The auxiliary coolant loop is for heating/cooling one or more components, such as a battery, dependent upon the mode of operation.