Reversible Heat Pump Valve Layout for Countercurrent Evaporation
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Solution Overview
Problem
Reversible heat pumps face efficiency issues when switching between heating and cooling modes due to the reversal of the refrigerant circuit, leading to reduced performance in one of the operating modes.
Innovation Solution
The implementation of non-return valves and a heat exchanger configuration that maintains a countercurrent flow direction for both refrigerant and heat transfer medium in both modes, ensuring the heat exchanger operates effectively as a countercurrent heat exchanger in both heating and cooling operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the refrigeration circuit is reversed to switch between heating and cooling modes, then the heat pump can provide both heating and cooling functions, but the flow direction of the heat exchanger changes on the refrigerant side causing reduced efficiency and increased mean temperature difference
Solution Approach 1:
The patent applies the inversion principle by reversing the refrigerant flow direction through the use of a 4-2-way valve to switch between heating and cooling modes. This allows the heat pump to provide both functions while managing the efficiency trade-off through proper valve control and heat exchanger configuration.
Solution Approach 2:
The patent implements dynamics by making the refrigerant flow direction changeable through the 4-2-way valve, allowing the system to adapt its operation mode dynamically. The heat exchanger configuration is designed to accommodate changing flow directions while maintaining countercurrent flow in both modes for optimal efficiency.
2Adaptability or versatility
If the refrigeration circuit is reversed, then cooling mode operation is achieved, but the mean temperature difference between refrigerant and water or air increases reducing coefficient of performance
Solution Approach 1:
The patent uses the inversion principle to reverse the refrigerant circuit configuration when switching to cooling mode. The 4-2-way valve redirects the refrigerant flow through the heat exchangers in the opposite direction, enabling cooling operation while attempting to maintain efficient heat transfer characteristics.
Solution Approach 2:
The patent applies parameter changes by altering the refrigerant flow direction and heat exchanger configuration when switching between heating and cooling modes. The system adjusts its operational parameters through valve control to optimize performance for the current mode, though the mean temperature difference inherently increases in cooling mode.
3Productivity
If reversible heat pumps are optimized for heating operation, then heating performance is improved, but cooling performance becomes modest and vice versa
Solution Approach 1:
The patent implements universality by designing the heat pump system with a 4-2-way valve and configurable heat exchangers that allow the same hardware to perform both heating and cooling functions effectively. The system is optimized to provide adequate performance in both modes rather than being specialized for only one function.
Solution Approach 2:
The patent uses dynamics to allow the heat pump to adapt its operation between heating and cooling modes through the 4-2-way valve. The system can dynamically switch between optimized heating configuration and optimized cooling configuration, providing versatile functionality while maintaining reasonable performance in both modes.
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
This configuration enhances the heat pump's coefficient of performance by maintaining efficient operation in both heating and cooling modes, improving overall system effectiveness.
Implementation Method 1
the heat exchanger in both operating modes as ( Cross) can work countercurrent heat exchanger
Implementation Method 2
a heat exchanger, which works as an evaporator in heating mode and as a condenser in cooling mode, can be flowed through in both operating modes by both refrigerant and, for example, heating water in the same direction
Implementation Method 3
The provision of thermal heat in heat pumps takes place through the condensation of refrigerant under high pressure and thus at high temperature
Implementation Method 4
The liquefied refrigerant is then expanded in a throttle element, for example an expansion valve, and then evaporates in the evaporator of the heat pump, absorbing ambient heat
Implementation Method 5
The refrigerant vapor is compressed by the heat pump's compressor so that it can then be condensed again in the heat pump's condenser
Data Source
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AI summary
The system has valves (20, 21) provided in front of an evaporator (3), and valves (17, 18) provided behind the evaporator. Two paths (B, C) are provided parallel to the evaporator. The valves (17, 18, 20, 21) are designed such that a flow direction at the evaporator is unchanged independent of change of a flow direction of a refrigerant e.g. carbon hydride. The evaporator is used as a liquefier in an operation mode for liquefying the refrigerant and is used as a vaporizer in another operation mode for evaporating the refrigerant.