Heat Pump Refrigerant Separation for Geodetic Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing heat pump systems using flammable refrigerants face challenges in detecting and managing leaks into the heating circuit due to pressure differences and geodetic height, leading to refrigerant accumulation and potential system failure.
Innovation Solution
The system positions the heating circuit pump downstream of the refrigerant/air separator and safety valve within the heat pump enclosure, with the safety valve in the heat pump housing having a lower opening pressure than other safety valves, ensuring controlled release of refrigerant into an expansion vessel, thus preventing system failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the heat pump is installed at the top of the building, then the refrigerant/air separator and safety valve form the highest point for refrigerant accumulation, but the geodetic pressure difference reduces the effectiveness of safety valves in lower locations
Solution Approach 1:
The safety valve in the heat pump is calibrated with a lower opening pressure than safety valves in the building's heating circuit, compensating for the geodetic pressure difference caused by the heat pump's elevated installation position. This ensures the safety valve opens at the appropriate pressure regardless of its height in the system.
2Reliability
If refrigerant accumulates in the heating circuit, then it displaces heating water and reduces system efficiency, but stopping water circulation requires additional control mechanisms
Solution Approach 1:
The heating circuit pump is positioned downstream of the refrigerant/air separator and safety valve, creating a configuration where refrigerant accumulation naturally fills the pump housing and stops circulation before refrigerant can be transported throughout the heating system. This preliminary positioning prevents the need for additional active control mechanisms.
3Reliability
If the safety valve opening pressure is set lower in the heat pump, then refrigerant can be released at a defined point, but this creates a pressure imbalance with other safety valves in the building's heating circuit
Solution Approach 1:
The safety valve in the heat pump is given a distinct, lower opening pressure setting compared to safety valves in the building's heating circuit. This localized parameter differentiation ensures that the heat pump's safety valve opens first to release refrigerant, while other safety valves remain closed and only release heating water if needed.
4Reliability
If multiple safety valves are installed in the building's heating circuit, then refrigerant can be contained to the heat pump, but this increases the complexity of the safety valve system
Solution Approach 1:
The refrigerant/air separator acts as an intermediary component between the internal heat exchanger and the heating circuit, providing a separation zone that prevents refrigerant from mixing with heating water. This intermediary structure simplifies the overall safety system by containing refrigerant issues to a specific location rather than requiring complex multi-valve coordination.
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 configuration effectively manages refrigerant leaks by ensuring controlled discharge and preventing pump failure, maintaining system integrity and safety.
Implementation Method 1
which in such cases often has a separating device for air and gaseous refrigerant
Implementation Method 2
heating pumps are centrifugal pumps and cannot pump gas
Implementation Method 3
The opening pressure of the safety valve in the heat pump is lower than the opening pressure of the other safety valves in the building's heating circuit
Implementation Method 4
the internal heat exchanger connected to the flammable refrigerant on one side and to the heating circuit water on the other side
Implementation Method 5
transfers heat from the refrigerant to the heating circuit
Data Source
Figure 1
Figure 2
AI summary
Installation of a heat pump in a building, the installation comprising: a heat pump operated with a flammable refrigerant (11), wherein the heat pump is located in a casing (9) and the casing is located in a building, in the casing (9) of the heat pump an internal heat exchanger (1) which is connected to the flammable refrigerant (11) on one side and to the heating circuit water (10) on the other side, in the casing (9) of the heat pump a refrigerant/air separator (2) which is arranged downstream in the heating circuit behind the internal heat exchanger (1), in the casing (9) of the heat pump a safety valve (4) which is arranged downstream in the heating circuit behind the refrigerant/air separator (2), a heating circuit pump (5) which is arranged downstream in the heating circuit behind the safety valve (4), at least one heating consumer (8) with a hot water supply and a hot water return,A further safety valve (6) is located between the hot water inlet and the heating circuit pump (5), and a water expansion tank (7) is located between the hot water return and the internal heat exchanger (1), wherein the safety valve (4) in the heat pump housing (9) has a lower opening pressure than the safety valve (6) between the heating circuit pump (5) and the heat consumer (8), and the difference in opening pressure is set to be greater than the pressure difference due to the geodetic height of the water column between the two safety valves (4, 6).