Refrigerant Redirection Valves for Adaptive Heat Pump Dryers
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Solution Overview
Problem
Existing household appliances with heat pumps, such as laundry drying machines, face challenges in regulating the heat exchange capacity of heat exchangers, as the operation of the compressor cannot adapt to varying demands, leading to suboptimal performance during different phases of the drying cycle.
Innovation Solution
Incorporating a refrigerant redirection device, specifically a 4/2 directional control valve, that reverses the flow direction of the refrigerant through the condenser and/or evaporator, allowing independent regulation of heat exchanger capacities without altering the compressor's operation, and enabling easy integration into existing appliances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the compressor operation is used to regulate heat exchange capacity, then the heat pump can maintain stable operation, but the heat exchange capacity cannot be adapted to varying demands during different phases of the drying cycle
Solution Approach 1:
The patent segments the refrigerant flow path by introducing a refrigerant redirection device with multiple valves that can independently control refrigerant distribution to different heat exchangers. This allows the system to selectively activate or deactivate specific heat exchangers (evaporator, condenser, or both) based on the drying phase requirements, thereby achieving adaptable heat exchange capacity without affecting compressor operation.
2Adaptability or versatility
If a refrigerant redirection device is added to regulate heat exchanger capacity, then heat exchange conditions can be adjusted, but the device complexity increases
Solution Approach 1:
The refrigerant redirection device is designed with multi-functionality, where a single valve assembly can direct refrigerant flow to multiple different paths and control multiple heat exchangers. This universal design allows one component to perform the work of what would otherwise require multiple separate components, thereby reducing overall system complexity while maintaining the ability to regulate heat exchange capacity.
3Ease of operation
If the refrigerant flow direction through the condenser and evaporator is reversed, then the heat exchange capacity can be regulated independently from the compressor, but the system requires additional redirection components
Solution Approach 1:
The patent merges the refrigerant redirection functionality with the existing heat exchanger assembly by integrating valves and flow control mechanisms directly into the heat pump circuit. This combining approach allows the system to reverse refrigerant flow direction and regulate heat exchanger capacity independently while minimizing the addition of separate, standalone redirection components.
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 solution enhances the heat exchange conditions between the refrigerant and process air, allowing for adjustable heat exchange capacities, leading to improved energy efficiency and reduced energy consumption while maintaining drying performance.
Implementation Method 1
which is then evaporated again at the evaporator by the humid air coming from the load to be dried
Implementation Method 2
which is able to condense at the condenser due to being cooled down by the dry air
Implementation Method 3
The temperature difference between the condenser and the evaporator is produced due to compressing a previously evaporated refrigerant in a superheated gas state
Data Source
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AI summary
A household appliance (1) comprises a heat pump (2), the heat pump (2) comprising a compressor (3), a condenser (4), an expansion device (5), and an evaporator (6) connected in series by a refrigerant circuit, wherein the household appliance (1) further comprises at least one refrigerant redirection device (8, 9) to reverse a flow direction of a refrigerant (R) through the condenser (4) and/or through the evaporator (6). A method for operating a household appliance (1) comprising a heat pump (2), the heat pump (2) comprising a compressor (3), a condenser (4), an expansion device (5), and an evaporator (6) connected in series by a refrigerant circuit (7), wherein the household appliance (1) further comprises at least one refrigerant redirection device (8, 9), the method comprising switching at least one refrigerant redirection device (8, 9) to reverse a flow direction of a refrigerant (R) through the evaporator (6) and/or through the condenser (4). The invention is particularly useful for laundry drying appliances.