Refrigerant Pressure Control for Balanced Multi-Heat-Exchanger Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The refrigeration system experiences an imbalance in refrigerant flow between the heat-source heat exchanger and heat-using heat exchangers, leading to insufficient refrigerant supply and reduced heating/cooling capabilities, particularly when the heat-source heat exchanger functions as a condenser and at least one heat-using heat exchanger functions as a condenser or evaporator.
Innovation Solution
The system incorporates a high-pressure-side and low-pressure-side pressure difference detection mechanism to adjust the degree of opening of the heat-source expansion valve, maintaining a sufficient pressure difference between the high-pressure refrigerant and the refrigerant in the liquid pipe, ensuring a stable refrigerant flow to all heat exchangers, even when multiple heat exchangers operate as condensers or evaporators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the degree of opening of the heat-using expansion valve is increased to increase refrigerant flow to the heat-using heat exchanger, then the heating capability is improved, but the pressure difference between the high pressure refrigerant and the refrigerant in the liquid pipe is reduced, causing refrigerant to flow primarily into the heat-source heat exchanger
Solution Approach 1:
The control device monitors the pressure difference between the high-pressure refrigerant and the refrigerant in the liquid pipe, and automatically adjusts the degree of opening of the heat-source expansion valve to maintain the pressure difference above a predetermined threshold, preventing refrigerant flow imbalance
Solution Approach 2:
The system dynamically changes the degree of opening parameter of the heat-source expansion valve based on real-time pressure difference measurements, optimizing refrigerant distribution between heat exchangers under varying operating conditions
2Stability of the object's composition
If the degree of opening of the heat-source expansion valve is reduced to maintain pressure difference, then refrigerant flow balance is improved, but the heating capability of the heat-using heat exchanger deteriorates
Solution Approach 1:
The control device continuously monitors both the pressure difference and the operational status of heat exchangers, adjusting the heat-source expansion valve opening to maintain flow balance while ensuring sufficient refrigerant supply to heat-using heat exchangers for adequate heating capability
Solution Approach 2:
The system dynamically adjusts the heat-source expansion valve opening based on real-time operating conditions, allowing the refrigerant flow distribution to adapt to changing heating/cooling demands while maintaining stable pressure difference
3Adaptability or versatility
If multiple heat exchangers operate as condensers simultaneously, then heating demand satisfaction is improved, but refrigerant flow imbalance occurs leading to insufficient refrigerant supply
Solution Approach 1:
The control device monitors the operational status of multiple heat exchangers and the pressure difference in the refrigerant circuit, automatically adjusting the heat-source expansion valve to maintain reliable refrigerant supply distribution when multiple heat exchangers operate as condensers simultaneously
Solution Approach 2:
The system adjusts the expansion valve opening parameter in response to the number and operational status of heat exchangers, optimizing refrigerant flow distribution to maintain reliable supply to all active heat exchangers under varying heating/cooling demand configurations
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 prevents refrigerant flow imbalances, ensuring a sufficient refrigerant supply to all heat exchangers, maintaining reliable heating and cooling capabilities and improving the overall performance of the refrigeration system.
Implementation Method 1
a high-pressure-side pressure difference detection means which detects an index of pressure difference between a high pressure refrigerant and a refrigerant in the liquid pipe (15)
Implementation Method 2
adjusts the degree of opening of the heat-source expansion valve (23) in the concurrent operation so that a value detected by the high-pressure-side pressure difference detection means (Ps1, Ps3, Ts7) becomes larger than a predetermined value
Data Source
AI summary
In concurrent operation of performing a refrigeration cycle in which an outdoor heat exchanger (22) functions as a condenser, and at least one of a plurality of indoor heat exchangers (31, 41, 51) functions as a condenser, pressure difference ΔP1 between a high pressure refrigerant an a refrigerant in a liquid pipe (15) is detected, and the degree of opening of an outdoor expansion valve (23) is adjusted so that the pressure difference ΔP1 becomes larger than a predetermined target value.