Safety device for heat pump device and heat pump device
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Solution Overview
Problem
Existing safety devices for heat pumps can lead to unintentional shutdowns during heating or defrosting operations, and they do not effectively prevent the freezing of the heat transfer medium in the heat exchanger or refrigerant leaks due to complex control systems.
Innovation Solution
A safety device comprising a first pressure switch and a temperature switch, or alternatively a second pressure switch, that monitor refrigerant pressure and temperature, respectively, to ensure the heat pump is only shut down when both switches open, preventing unintentional shutdowns and freezing, using electromechanical components without complex control systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a complex control system is used to monitor safety devices, then the reliability of preventing freezing and leaks is improved, but the device complexity increases and unintentional shutdowns occur
Solution Approach 1:
The safety device is segmented into two independent pressure switches (first and second pressure switches) that monitor different pressure thresholds. Each switch operates autonomously to detect specific hazardous conditions (freezing risk and refrigerant leak risk) without requiring complex integrated control logic, thereby maintaining reliability while reducing system complexity.
Solution Approach 2:
The pressure switches are designed to automatically detect and respond to hazardous conditions without requiring external control system intervention. The switches independently open or close based on pressure threshold violations, enabling the system to self-monitor and self-protect against freezing and leaks, eliminating the need for complex control algorithms.
2Device complexity
If a single pressure switch is used to monitor refrigerant pressure, then the device complexity is reduced, but the reliability of preventing both freezing and leaks deteriorates
Solution Approach 1:
The monitoring function is segmented into two distinct pressure switches, each dedicated to detecting a specific type of hazardous condition. The first pressure switch monitors for freezing conditions by detecting when refrigerant pressure drops below a first threshold, while the second pressure switch monitors for refrigerant leaks by detecting when pressure exceeds a second threshold. This segmentation enables comprehensive safety monitoring with simple, dedicated components.
Solution Approach 2:
The pressure switching mechanism serves multiple safety functions through two independently configured switches. Both switches use the same basic pressure-sensitive technology but are calibrated to different thresholds and locations to provide universal protection against different failure modes (freezing and leaks), achieving multi-functionality without increasing component complexity.
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
Ensures reliable and simple shutdown of the heat pump to prevent freezing and refrigerant leaks, maintaining operational stability by using basic electromechanical switches that are self-resetting, thus avoiding unnecessary shutdowns.
Implementation Method 1
The first pressure switch is configured to monitor the refrigerant pressure in the refrigerant circuit of the heat pump device. In other words, the first pressure switch measures the refrigerant pressure in the refrigerant circuit or in a line (e.g., supply or return) of the refrigerant circuit.
Implementation Method 2
The temperature switch is configured to monitor the temperature of the refrigerant in the refrigerant circuit of the heat pump device. In other words, the temperature switch measures the temperature of the refrigerant in the refrigerant circuit or in a line (e.g., supply or return) of the refrigerant circuit.
Implementation Method 3
In a heat pump's refrigerant circuit, the refrigerant absorbs heat from the surrounding medium and evaporates during heating operation.
Implementation Method 4
the refrigerant absorbs heat from the surrounding medium and evaporates during heating operation
Implementation Method 5
Here, heat is transferred from the refrigerant, compressed by a compressor, to a heat transfer medium in a heating circuit
Implementation Method 6
the refrigerant changing from a gaseous to a liquid state
Implementation Method 7
The first pressure switch and the temperature switch or the second pressure switch are self-resetting
Data Source
Figure 1
Figure 2
Figure 3a
AI summary
The present invention relates to a safety device for a reversible heat pump device (10) with a refrigerant circuit coupled to a heat transfer circuit (20) via a first heat exchanger (13). The safety device comprises a first pressure switch for monitoring the pressure of a refrigerant in the refrigerant circuit of the heat pump device (10) and a temperature switch for monitoring the temperature of the refrigerant in the refrigerant circuit of the heat pump device (10). The first pressure switch comprises a first switch (S1) configured to open when the refrigerant pressure is less than a first predetermined pressure limit. The temperature switch comprises a second switch (S2) configured to open when the refrigerant temperature exceeds a predetermined temperature limit.The first switch (S1) is arranged in parallel to the second switch (S2), so that the power supply to the heat pump device (10) is interrupted if the first switch (S1) and the second switch (S2) are open.