Heat Pump Load Distribution Control for Fixed-Ratio Compression
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Solution Overview
Problem
In heat pump systems with a multi-stage compression refrigeration cycle and a fixed capacity ratio, energy consumption efficiency is insufficient due to the inability to freely regulate the temperatures of refrigerant discharged from the high-stage and low-stage compressors, limiting the control over the flow rate ratio of water for heating.
Innovation Solution
Implementing a load distribution control mechanism that regulates the flow rate of refrigerant through heat exchangers to reduce the temperature difference between the refrigerant discharged from the high-stage and low-stage compressors, using a flow rate regulation mechanism to optimize energy consumption efficiency and prevent damage to heat exchangers from low fluid flow speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a fixed capacity ratio multi-stage compression system is used, then the compression efficiency is satisfactory, but the energy consumption efficiency is insufficient due to inability to freely regulate refrigerant temperatures
Solution Approach 1:
The patent applies dynamics by making the water flow rate ratio adjustable rather than fixed. The control unit dynamically changes the flow rate ratio of water to the high-stage and low-stage heat exchangers based on operating conditions, enabling the system to adapt to varying thermal demands while maintaining efficient energy consumption. This dynamic adjustment compensates for the fixed capacity ratio limitation of the compression system.
Solution Approach 2:
The patent changes the parameter of water flow rate distribution between heat exchangers to optimize energy consumption. By varying the flow rate ratio parameter in response to different operating conditions (such as ambient temperature, heating demand), the system achieves satisfactory energy consumption efficiency despite the fixed compressor capacity ratio.
2Loss of energy
If the flow rate ratio of water for heating is set to optimize energy efficiency, then the COP improves, but the fluid flow speed may become too low causing damage to heat exchangers
Solution Approach 1:
The patent implements feedback control by continuously monitoring the flow rate ratio and adjusting it based on operating conditions. The control unit receives information about system performance and environmental conditions, then adjusts the water flow distribution to maintain both high COP and adequate flow speeds. This feedback mechanism prevents the system from operating in conditions that would cause heat exchanger damage while preserving energy efficiency.
Solution Approach 2:
The system dynamically adjusts the water flow rate ratio to balance two competing requirements: maximizing COP by optimizing heat exchange efficiency and maintaining sufficient flow speed to prevent heat exchanger damage. The control unit modifies the flow distribution in real-time based on operating conditions, ensuring both performance and reliability.
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 approach enhances energy consumption efficiency by optimizing the coefficient of performance (COP) and annual performance factor (APF), while reducing damage to heat exchangers and ensuring efficient heating by controlling the flow rate and temperature of refrigerant.
Implementation Method 1
a low-stage compression mechanism (22) that compresses the refrigerant to an intermediate pressure
Implementation Method 2
a high-stage compression mechanism (26) that compresses the refrigerant to a high pressure
Implementation Method 3
a first heat exchanger (5) that heats water by using heat from the refrigerant compressed by the low-stage compression mechanism (22)
Implementation Method 4
a second heat exchanger (6) that heats water by using heat from the refrigerant compressed by the high-stage compression mechanism (26)
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Provided is a heat pump system that can make energy consumption efficiency satisfactory even when a fixed capacity ratio type multi-stage compression refrigeration cycle is used. A compression mechanism (20) has a low-stage compression mechanism. (22) and a high-stage compression mechanism (26) having a fixed capacity ratio relationship. A mixing valve (91) regulates the ratio between the flow rate of water flowing to an intercooler hot-water supply flow passage (90A) and the flow rate of water flowing to a gas cooler hot-water supply flow passage (90B). A controller (2) operates the mixing valve (91) so as to reduce the difference between an outlet refrigerant temperature of an intercooler (5) and an outlet refrigerant temperature of the high-stage compression mechanism (26).