A heat pump
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Solution Overview
Problem
Heat pumps face challenges in operating across a large temperature range without compressor failure, as increased gas injection to meet capacity demands can lead to compressor overload.
Innovation Solution
A heat pump system with a compressor, heat exchangers, and injection valves, controlled by a controller to manage gas and liquid refrigerant injection, allowing for adjustable operation modes to balance capacity and prevent overload, including gas injection, liquid injection, and bypass valve operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If gas injection is increased to meet compressor capacity demands, then compressor capacity is improved, but compressor reliability deteriorates due to overloading
Solution Approach 1:
The patent changes the physical state parameter of the refrigerant by injecting liquid refrigerant instead of gaseous refrigerant. This parameter change allows the refrigerant to expand within the compressor, providing capacity increase while controlling the compression process to avoid overload conditions
Solution Approach 2:
The patent applies partial action by injecting a controlled amount of liquid refrigerant into the compressor suction port. This partial injection provides enough capacity boost to meet demand without excessive injection that would cause overload and reliability issues
2Loss of energy
If gas injection is increased to improve coefficient of performance, then coefficient of performance is improved, but compressor load increases leading to potential failure
Solution Approach 1:
The patent changes the refrigerant state from gas to liquid before injection. This parameter change enables the refrigerant to undergo expansion within the compressor, improving thermodynamic efficiency and coefficient of performance while the controlled injection rate prevents excessive compressor load
3Adaptability or versatility
If the heat pump operates across a large temperature range, then adaptability is improved, but compressor reliability deteriorates due to increased capacity demands
Solution Approach 1:
The patent implements a dynamic control system that adjusts the liquid refrigerant injection rate based on operating conditions. This dynamic adjustment allows the heat pump to adapt to various temperature ranges while maintaining compressor reliability through proportional control of the injection amount
Solution Approach 2:
The patent uses feedback control where the controller monitors compressor operation and adjusts the liquid refrigerant injection rate accordingly. This feedback mechanism ensures that the injection amount is optimized for each operating condition, expanding the safe operation range while preventing compressor overload
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
Enables the heat pump to operate effectively across a wide temperature range while preventing compressor failure by optimizing refrigerant injection and bypass operations, enhancing coefficient of performance and compressor efficiency.
Implementation Method 1
The controller is configured to operate the gas injection valve to inject at least partly gaseous refrigerant into the compressor through the injection port
Implementation Method 2
The controller is further configured to operate the liquid injection valve to inject substantially liquid refrigerant into the compressor through the suction port of the compressor
Implementation Method 3
a utilization side heat exchanger, a main expansion mechanism and a heat source side heat exchanger arranged in a refrigeration path
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure relates to a heat pump (100) comprising a compressor (101) for compressing a refrigerant, a first heat exchanger (102), a main expansion mechanism (103) and a second heat exchanger (104) arranged in a refrigeration path (120); the compressor having a suction port (101a), a compression port (101c) and an injection port (101b); a gas injection valve (112) connected on a first side (112a) to the refrigeration path between the first heat exchanger and the main expansion mechanism and on a second side (112b) to the injection port of the compressor; a liquid injection valve (111) connected on a first side (111a) to the refrigeration path between the first heat exchanger and the main expansion mechanism and on a second side (111b) between the second heat exchanger and the suction port of the compressor; and a controller (130), the controller (130) being configured to operate the gas injection valve (112) to inject at least partly gaseous refrigerant into the compressor through the injection port, and to operate the liquid injection valve (111) to inject substantially liquid refrigerant into the compressor through the suction port of the compressor.