Heat Pump Leak Isolation Using Pressure-Sensed Shut-Off Valves
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Solution Overview
Problem
Heat pumps using alternative refrigerants like propane or isobutane face challenges in accurately detecting refrigerant leaks, leading to potential fires, low heat exchange efficiency, and compressor damage due to high flammability and insufficient refrigerant circulation.
Innovation Solution
A heat pump system with shut-off valves and a controller that determines refrigerant leaks through pressure sensors, temperature sensors, and power consumption monitoring, closing valves to prevent further leakage and discharge refrigerant outdoors using a ventilation fan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If refrigerant leakage is not accurately detected, then system simplicity is maintained, but safety deteriorates due to potential fires
Solution Approach 1:
The detection system is segmented into multiple independent sensing components: a pressure sensor for detecting pressure changes indicating leakage, a temperature sensor for detecting temperature variations, and a controller for processing signals. This segmentation allows the system to achieve high safety through multiple detection methods while keeping each individual component relatively simple and manageable.
Solution Approach 2:
The system implements feedback mechanisms where the pressure sensor and temperature sensor continuously monitor refrigerant conditions and feed information to the controller. When the controller detects abnormal readings indicating leakage, it provides feedback by triggering alarm signals or shutting down the system, creating a closed-loop safety mechanism that enhances reliability without requiring overly complex detection architecture.
2Loss of substance
If sufficient refrigerant is not circulated due to leakage, then refrigerant loss is reduced, but heat exchange efficiency deteriorates
Solution Approach 1:
The system performs preliminary detection of refrigerant leakage using pressure and temperature sensors before significant refrigerant loss or efficiency degradation occurs. By detecting leakage early and triggering alarm signals or shutting down the system, the patent prevents both substantial refrigerant loss and severe efficiency deterioration, addressing both concerns through early intervention.
Solution Approach 2:
The pressure sensor and temperature sensor provide continuous feedback on refrigerant circulation conditions to the controller. When leakage is detected through abnormal pressure or temperature readings, the controller responds by triggering alarms or shutting down the system, creating a feedback loop that prevents both significant refrigerant loss and severe heat exchange efficiency degradation by intervening at the first sign of problems.
3Loss of substance
If sufficient refrigerant is not circulated due to leakage, then refrigerant loss is reduced, but compressor damage risk increases
Solution Approach 1:
The system performs preliminary detection of refrigerant leakage using pressure sensors and temperature sensors before compressor damage can occur. By detecting leakage early and triggering alarm signals or shutting down the compressor, the patent prevents both significant refrigerant loss and compressor damage, addressing both concerns through early intervention before damage accumulates.
Solution Approach 2:
The patent introduces an intermediary detection and control system including pressure sensors, temperature sensors, and a controller that acts as a mediator between refrigerant leakage and potential compressor damage. This intermediary system monitors refrigerant parameters continuously and intervenes by triggering alarms or shutting down the compressor when leakage is detected, thereby protecting the compressor while minimizing refrigerant loss.
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
Accurately detects refrigerant leaks, prevents further leakage, and safely discharges refrigerant outdoors, enhancing safety and reliability by reducing fire risks and maintaining efficient operation.
Implementation Method 1
a pressure sensor detecting a pressure of the refrigerant flowing between the compressor and the water refrigerant heat exchanger
Implementation Method 2
a water refrigerant heat exchanger for heat-exchanging the refrigerant and water
Implementation Method 3
an outdoor heat exchanger for heat-exchanging the refrigerant and outdoor air
Implementation Method 4
a compressor for compressing a refrigerant
Data Source
AI summary
A heat pump including a housing configured to be disposed outdoors; a compressor that compresses a refrigerant; a fluid refrigerant heat exchanger configured to perform heat exchange between the refrigerant and a fluid; an outdoor heat exchanger configured to perform heat exchange between the refrigerant and outdoor air; a pressure sensor configured to detect a pressure of the refrigerant flowing between the compressor and the fluid refrigerant heat exchanger; a first shut-off valve disposed in a pipe connected to a discharge of the compressor; a second shut-off valve disposed between the outdoor heat exchanger and the compressor; and a controller configured to: determine whether the refrigerant leaks, control the first shut-off valve to be closed, when the refrigerant leaks, and control the second shutoff valve to be closed, when the pressure sensed by the pressure sensor is less than a predetermined reference pressure.