Refrigeration heat pump unit
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Solution Overview
Problem
Centrifugal refrigeration heat pump units require multiple stages of impellers to achieve high compression ratios, leading to inefficiencies in double-working conditions.
Innovation Solution
A refrigeration heat pump unit with a centrifugal compressor featuring two independent motors driving separate impellers, each with its own compression chamber and bypass flow paths, controlled by a controller to optimize operation based on working conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If multiple stages of impellers are mounted on a rotating shaft to achieve high compression ratio, then the compression ratio requirement is met, but all impellers operate at the same rotation speed making it difficult to achieve high-efficiency design in double-working condition application
Solution Approach 1:
The patent divides the single rotating shaft system into multiple independent rotating shafts, each driving its own impeller. This segmentation allows each impeller to operate at independently controlled rotation speeds, enabling optimized efficiency for different working conditions (cold water preparation and hot water preparation) while maintaining the required high compression ratio through multi-stage compression.
Solution Approach 2:
The patent implements dynamic control by allowing each motor driving an impeller to operate at independently adjustable rotation speeds. This dynamic capability enables the system to adapt to varying working conditions by optimizing the rotation speed of each impeller according to the specific requirements of cold water or hot water preparation modes.
2Device complexity
If a single rotating shaft drives multiple impellers to simplify structure, then device complexity is reduced, but independent speed control for optimizing part load value cannot be achieved
Solution Approach 1:
The patent segments the drive system into multiple independent motor-shaft-impeller units. Although this increases structural complexity compared to a single shaft system, it enables independent speed control of each impeller, which significantly improves part load value by allowing the compressor to operate efficiently across a wider range of loading conditions.
Solution Approach 2:
The patent changes the operational parameters by allowing each impeller to operate at independently controlled rotation speeds. This parameter flexibility enables optimization of compression efficiency at different load levels, improving part load value while the modular design keeps the overall structure manageable.
3Device complexity
If multiple impellers operate at the same rotation speed to simplify control, then control system complexity is reduced, but efficiency optimization under varying load conditions cannot be achieved
Solution Approach 1:
The patent implements dynamic speed control for each impeller driven by its own motor. This allows the control system to optimize the rotation speed of each impeller according to the specific working conditions and load requirements, maximizing energy efficiency while the modular control architecture keeps the control system complexity manageable.
Solution Approach 2:
The patent enables independent adjustment of rotation speed parameters for each impeller. This parameter flexibility allows the system to adapt to varying load conditions by optimizing the operational parameters of each compression stage, thereby reducing energy losses while maintaining a relatively simple control structure through standardized control modules.
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
Enhances efficiency and reliability by allowing independent control of motor speeds and bypass flow paths, improving part load value and reducing refrigerant loss under varying load conditions.
Implementation Method 1
The first impeller is disposed inside the first compression chamber and is driven by the first motor. The second impeller is disposed inside the second compression chamber and is driven by the second motor.
Implementation Method 2
a refrigerant circuit formed by a centrifugal compressor, a condenser, a throttling device, and an evaporator
Implementation Method 3
the second discharge port communicating with an inlet of the condenser
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
There is provided a refrigeration heat pump unit (100), including a refrigerant circuit formed by a centrifugal compressor (1), a condenser (2), a throttling device, and an evaporator (3). The centrifugal compressor (1) includes a housing (10), a first motor (11), a second motor (12), a first compression chamber (13), a second compression chamber (14), a first impeller (15), a second impeller (16), and a controller (4). The first motor (11) is disposed inside the housing (10). The second motor (12) is disposed inside the housing (10) and disposed opposite to the first motor (11). The first compression chamber (13) is disposed at an end portion of the housing (10) close to the first motor (11) and includes a first suction port (131) and a first discharge port (132). The second compression chamber (14) is disposed at an end portion of the housing (10) close to the second motor (12) and includes a second suction port (141) and a second discharge port (142). The first impeller (15) is driven by the first motor (11), and the second impeller (16) is driven by the second motor (12). The controller (4) is configured to turn on the first motor (11) and turn off the second motor (12) in response to a first working condition, turn off the first motor (11) and turn on the second motor (12) in response to a second working condition, and turn on the first motor (11) and the second motor (12) in response to a third working condition.