Refrigerant Leak Circuit Isolation for Multi-Compressor HVAC Systems
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Solution Overview
Problem
In HVAC systems with multiple compressor circuits, detecting a refrigerant leak is challenging because the leak detection sensor is shared among all circuits, leading to inefficient shutdown of the entire system and underutilization of non-leaking circuits.
Innovation Solution
The system uses subcool, superheat, and saturated suction temperature values to identify which compressor circuit is associated with a refrigerant leak, isolates that circuit, and redistributes the air conditioning load to non-leaking circuits, ensuring seamless operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the entire HVAC system is shut down when a refrigerant leak is detected, then safety is ensured, but cooling service is lost and customer comfort deteriorates
Solution Approach 1:
The patent segments the HVAC system into multiple independent compressor circuits (first compressor circuit, second compressor circuit, etc.), each with its own refrigerant charge and operational status. When a leak is detected in one circuit, only that specific circuit is isolated while other circuits continue to provide cooling service, thus maintaining productivity while ensuring safety.
2Object-affected harmful factors
If the entire HVAC system is shut down when a refrigerant leak is detected, then harmful refrigerant release is prevented, but energy consumption increases due to loss of cooling
Solution Approach 1:
The system divides the refrigeration system into separate compressor circuits that can be independently controlled. When a leak is detected in one circuit, only that circuit is shut down to prevent harmful refrigerant release, while other circuits remain operational and continue to consume energy efficiently for providing cooling service.
3Reliability
If all compressor circuits are stopped when a leak is detected, then system safety is maintained, but the utilization efficiency of non-leaking circuits is reduced
Solution Approach 1:
The patent implements independent control of each compressor circuit through separate refrigerant lines and control mechanisms. When a leak is detected in one circuit, the control system isolates only that specific circuit while allowing other circuits to continue operating at full utilization efficiency, thus resolving the contradiction between safety and productivity.
4Device complexity
If a shared leak detection sensor is used for all compressor circuits, then device complexity is reduced, but the ability to identify the specific leaking circuit is lost
Solution Approach 1:
The patent assigns a dedicated leak detection sensor to each compressor circuit, creating independent detection channels. This segmentation allows the system to identify which specific circuit is leaking while maintaining relatively simple sensor technology in each circuit, balancing device complexity with information accuracy.
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 allows the HVAC system to continue providing air conditioning without interruption, balances the air conditioning load among non-leaking circuits, and identifies the location and component associated with the leak.
Implementation Method 1
a subcool sensor circuit configured to provide a subcool signal that indicates a subcool value associated with the condenser, wherein the subcool value corresponds to a temperature difference between a saturated refrigerant and a subcooled refrigerant associated with the condenser
Implementation Method 2
a superheat sensor circuit configured to provide a superheat signal that indicates a superheat value corresponding to a temperature difference between a superheated refrigerant and a saturated refrigerant state associated with the evaporator pressure
Implementation Method 3
a refrigerant detection sensor circuit that is common to all the refrigeration circuits and configured to detect a concentration of the refrigerant in a volume
Data Source
AI summary
A refrigeration system detects a refrigerant leak by detecting that a refrigerant concentration is more than a threshold concentration. In response, the system accesses subcool, superheat, and saturation suction temperature values associated with the compressor circuits. The system determines that the subcool value is less than a subcool threshold and whether the superheat value is more than a superheat threshold. In response, the system may determine that the compressor circuit associated with the subcool and superheat values is associated with the loss of charge. In response, the system isolates the compressor circuit from other components of the system and operates a blower. The system may continue cooling operation using non-leaking compressors.