Refrigeration System Leak Detection with Selective Unit Isolation
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Solution Overview
Problem
In refrigeration systems with multiple utilization units for a single air conditioning target space, detecting refrigerant leakage is challenging, leading to the need to shut down all units, which complicates maintaining the temperature, especially in large refrigeration or freezer warehouses.
Innovation Solution
Implementing a refrigerant leakage sensor and a control unit that performs detection standby control to temporarily stop refrigerant supply to utilization-side heat exchangers, allowing identification of the leaking unit and isolating it from the others, thereby minimizing leakage and maintaining temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a refrigerant leakage sensor is provided at the lower part of the air conditioning target space to detect refrigerant leakage, then the safety of the system is improved, but it becomes impossible to determine which specific utilization unit has leaked, forcing all units to be stopped
Solution Approach 1:
The patent divides the detection function into multiple sensors, each assigned to a specific utilization unit. Instead of using a single common sensor that cannot identify the source, multiple segmented sensors enable precise localization of leaks, allowing selective shutdown of only the affected unit while maintaining operation of others.
Solution Approach 2:
The patent introduces a control unit as an intermediary that receives signals from individual leakage sensors associated with each utilization unit. This control unit processes the information and determines which specific unit has leaked, enabling intelligent decision-making rather than blanket shutdown of all units.
2Object-affected harmful factors
If all utilization units are stopped when refrigerant leakage is detected, then the harmful effect of refrigerant accumulation is reduced, but the temperature maintenance of the air conditioning target space is compromised
Solution Approach 1:
By segmenting the shutdown control to affect only the specific utilization unit where leakage is detected rather than all units, the patent minimizes the impact on temperature maintenance while still addressing the refrigerant accumulation hazard in the affected area.
Solution Approach 2:
The patent applies local quality by implementing targeted shutdown control only in the specific zone (utilization unit) where leakage occurs, rather than applying a uniform shutdown to the entire system. This localized response maintains temperature stability in unaffected areas.
3Device complexity
If a single refrigerant leakage sensor is used for multiple utilization units, then the device complexity is reduced, but the measurement precision of the leakage source is lost
Solution Approach 1:
The patent segments the sensing system into multiple individual sensors, each dedicated to monitoring a specific utilization unit. This segmentation sacrifices some device simplicity but gains the critical capability of precise leakage source identification, which is essential for selective shutdown operation.
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 enables precise determination of the leaking unit, allowing continued operation of non-leaking units and reducing refrigerant leakage into the air conditioning space, thus maintaining the desired temperature effectively.
Implementation Method 1
The refrigerant leakage sensor detects a leakage of the refrigerant in a lower part of the air conditioning target space
Implementation Method 2
Each of the utilization units includes a utilization-side heat exchanger that exchanges heat between a refrigerant and air
Data Source
AI summary
A refrigeration system includes a plurality of utilization units provided for one air conditioning target space, a refrigerant leakage sensor that detects a leakage of the refrigerant in a lower part of the air conditioning target space, and a control unit. In a case where the refrigerant leakage sensor detects the refrigerant leakage, the control unit performs detection standby control on the utilization units such that the supply of the refrigerant to utilization-side heat exchangers is temporarily stopped. In a case where the refrigerant leakage is detected based on the state quantity of the refrigerant corresponding to the utilization units under the detection standby control, the control unit stops the use of the utilization unit in which the refrigerant leakage has been detected.