Heat Pump Refrigerant Bypass Control to Prevent Compressor Liquid Ingress
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Solution Overview
Problem
In heat pump apparatuses, reducing compressor operating frequency to prevent liquid refrigerant from entering the compressor leads to increased power consumption, and existing solutions either fail to prevent liquid refrigerant entry or increase power consumption.
Innovation Solution
Incorporating a third heat exchanger that allows the refrigerant to be heat-exchanged with a fluid circuit, enabling the refrigerant to be heated and evaporated before entering the compressor, thereby preventing liquid refrigerant entry without increasing compressor frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the operating frequency of the compressor is lowered to reduce power consumption, then power consumption is reduced, but the refrigerant cannot be completely evaporated and liquid refrigerant is drawn into the compressor
Solution Approach 1:
The invention introduces a preliminary heating action by adding a third heat exchanger that heats the refrigerant before it enters the compressor. This preliminary action ensures the refrigerant is completely evaporated even at low compressor frequencies, preventing liquid refrigerant from entering the compressor and maintaining reliable operation while allowing reduced power consumption
Solution Approach 2:
The third heat exchanger acts as an intermediary component between the second heat exchanger and the compressor. It provides an additional heating stage that mediates the temperature and evaporation state of the refrigerant, ensuring complete evaporation before compressor intake without requiring increased compressor frequency
2Reliability
If the operating frequency of the compressor is increased to prevent liquid refrigerant from entering the compressor, then liquid refrigerant entry is prevented, but power consumption increases
Solution Approach 1:
Instead of increasing compressor frequency to achieve complete evaporation, the invention performs preliminary heating in the third heat exchanger before the refrigerant enters the compressor. This separates the evaporation function from the compression function, allowing the compressor to operate at low frequency while still preventing liquid refrigerant entry
Solution Approach 2:
The invention segments the refrigerant heating process into multiple stages: first heat exchanger, second heat exchanger, and third heat exchanger. This segmentation allows each component to focus on a specific heating function, with the third heat exchanger specifically dedicated to ensuring complete evaporation before compressor intake, enabling low-frequency operation
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 effectively prevents liquid refrigerant from entering the compressor, maintaining efficient operation while reducing power consumption by ensuring the refrigerant is fully evaporated, even at low ambient temperatures.
Implementation Method 1
a third heat exchanger that makes a refrigerant that is to be drawn into a compressor heat-exchanged with a fluid circulating in a fluid circuit
Implementation Method 2
the refrigerant is heated by the fluid and can be turned into the gas refrigerant
Data Source
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AI summary
It is an object to prevent a liquid refrigerant from being drawn into a compressor. A heat pump apparatus (100) includes a refrigerant circuit (6) in which a refrigerant circulates, and which is configured by sequentially connecting a compressor (1), a first heat exchanger (2), an expansion valve (3), a second heat exchanger (4), and a third heat exchanger (5), and connecting a bypass flow path (9) bypassing the third heat exchanger between the second heat exchanger and the compressor. The heat pump apparatus also includes a water circuit (13) in which water circulates, and which is configured by sequentially connecting the third heat exchanger, the first heat exchanger, and a tank (12). In the heat pump apparatus, if there is a risk of the liquid refrigerant being drawn into the compressor, a three-way valve (10) is controlled such that the refrigerant flows through the third heat exchanger to be heated by water and evaporated.