Cascade Heat Pump Compressor Capacity Control to Reduce Indoor Noise
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Solution Overview
Problem
Conventional heat pump systems with capacity-variable compressors indoors produce harsh noise due to sudden capacity variations, which is undesirable for users.
Innovation Solution
A heat pump system design with a usage-side unit and a heat source unit, where the usage-side compressor's capacity is varied incrementally, and the heat source-side compressor's capacity is adjusted by controlling condensation target temperatures to maintain system balance and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the capacity of the usage-side compressor is suddenly varied to meet heating demands, then the system responsiveness and productivity are improved, but harsh noise is emitted from the compressor
Solution Approach 1:
The patent applies dynamics by making the compressor capacity variable rather than fixed. The usage-side compressor capacity is dynamically adjusted based on heating demands, allowing the system to respond flexibly to changing conditions while maintaining acceptable noise levels through controlled variation rates.
Solution Approach 2:
The patent implements periodic action by varying the compressor capacity in staged increments rather than suddenly. The capacity variation occurs over multiple cycles or time periods, with each stage allowing noise to dissipate before the next adjustment, thereby reducing harsh noise emissions while maintaining system responsiveness.
2Ease of operation
If the usage-side unit is installed indoors to provide warm water, then the ease of operation is improved, but noise from the compressor disturbs users
Solution Approach 1:
The patent uses dynamics to allow the indoor-installed usage-side compressor to operate at variable capacities. By adjusting the compressor capacity according to actual heating needs rather than running at full capacity continuously, the noise level is reduced while the convenience of having the warm water supply unit indoors is maintained.
3Productivity
If the heat source-side compressor capacity is increased to compensate for usage-side capacity reduction, then the system productivity is maintained, but the heat source-side noise increases
Solution Approach 1:
The patent merges the heat source-side refrigerant circuit and usage-side refrigerant circuit into an integrated system. By combining these circuits, the system can coordinate capacity adjustments between the heat source-side compressor and usage-side compressor, allowing the usage-side compressor to handle capacity variations for noise reduction while the heat source-side compressor maintains stable operation for productivity.
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 effectively reduces harsh noise emissions by incrementally varying compressor capacities, maintaining system balance and ensuring reliable operation while minimizing noise disturbance.
Implementation Method 1
the heat source-side heat exchanger... capable of functioning as an evaporator of the heat source-side refrigerant
Implementation Method 2
The heat source-side heat exchanger is capable of functioning as an evaporator of the heat source-side refrigerant
Implementation Method 3
the usage-side heat exchanger... functioning as a radiator of the heat source-side refrigerant and functioning as an evaporator of the usage-side refrigerant
Implementation Method 4
the refrigerant-water heat exchanger... capable of functioning as a radiator of the usage-side refrigerant and heating an aqueous medium
Data Source
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AI summary
To prevent noise emitted along with changes in the operating capacity of a usage-side compressor from being harsh to a user. A heat pump system (1) has a heat source unit (2), a usage-side unit (4), and a usage-side controller (12). The heat source unit (2) has a heat source-side compressor (21) for compressing a heat source-side refrigerant, and a heat source-side heat exchanger (24) capable of functioning as an evaporator of the heat source-side refrigerant. The usage-side unit (4) is connected to the heat source unit (2), and the usage-side unit (4) has a capacity-variable-type usage-side compressor (62) for compressing a usage-side refrigerant, a usage-side heat exchanger (41) capable of functioning as a radiator of the heat source-side refrigerant and functioning as an evaporator of the usage-side refrigerant, and a refrigerant-water heat exchanger (65) capable of functioning as a radiator of the usage-side refrigerant and heating an aqueous medium. A usage-side controller (12) performs usage-side capacity variation control for incrementally varying the operating capacity of the usage-side compressor (62) during a usual operation.