Heat Pump Dynamic Mode Control for COP Under Variable Load
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Solution Overview
Problem
Heat pump systems face inefficiencies and temperature control challenges due to oversizing during low heat loads, leading to frequent on-off cycling and reduced COP, making it difficult to achieve maximum efficiency under varying environmental conditions.
Innovation Solution
A method for operating a heat pump system that involves a control element determining the current performance and comparing it to stored performance, adjusting operating modes based on differences exceeding a threshold, and considering the heat storage level to optimize heat pump and storage element operations, thereby maintaining maximum COP performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the heat pump system is sized for maximum heating capacity, then it can meet high heat load demands, but it becomes oversized and operates inefficiently during low heat load conditions
Solution Approach 1:
The patent implements dynamic operation modes (storage charging, storage discharging, direct heating) that allow the heat pump system to adapt its operation based on real-time conditions. The control element dynamically switches between these modes to optimize performance, enabling the system to operate efficiently across varying heat load conditions rather than being stuck in a fixed oversized configuration.
Solution Approach 2:
The system pre-charges the thermal storage element during periods of high heat load or low ambient temperature when the heat pump operates efficiently. This preliminary action stores thermal energy in advance, allowing the system to meet subsequent low heat load demands from storage without running the heat pump, thereby avoiding inefficient operation during partial load conditions.
2Productivity
If the heat pump frequently switches on and off to match low heat load demands, then it can avoid oversizing, but the lifetime is reduced and efficiency deteriorates
Solution Approach 1:
The thermal storage element acts as a buffer that enables continuous heat supply to the building without requiring frequent on-off cycling of the heat pump. The heat pump can operate continuously or for extended periods charging the storage, while the storage discharge phase provides continuous heat coverage during low demand periods, eliminating short cycling and its associated reliability problems.
3Ease of operation
If the target flow temperature is computed directly from conventional heat curve method, then the control is simple, but it is very difficult to achieve maximum COP under different conditions of ambient temperature and target flow temperature
Solution Approach 1:
The control element uses feedback from ambient temperature sensors and thermal storage level sensors to dynamically adjust the operating mode and temperature setpoints. The system continuously monitors actual conditions and adjusts the heat pump operation and storage charging/discharging decisions based on real-time feedback, enabling maximum COP achievement across varying conditions while maintaining automated simplicity.
Solution Approach 2:
The system dynamically changes operating parameters including flow temperature setpoints, power demand levels, and operating modes based on ambient temperature and storage level conditions. Rather than using a fixed heat curve, the control element adjusts multiple parameters simultaneously to optimize COP for current environmental conditions, achieving better efficiency while maintaining ease of automated operation.
4Temperature
If the heat pump operates at maximum power to achieve desired temperature quickly, then the heating demand is met, but the COP decreases due to oversizing effect
Solution Approach 1:
The system charges the thermal storage element in advance during periods when heat pump operation is efficient (high ambient temperature, high heat demand). This preliminary energy storage allows subsequent rapid temperature achievement during low-demand periods without requiring the heat pump to operate at maximum power, thereby maintaining high COP while still meeting heating demands quickly when needed.
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 enhances the efficiency of the heat pump system by maintaining optimal operating modes, reducing wear and tear, and achieving desired temperatures under different conditions, thereby improving overall energy efficiency.
Implementation Method 1
refrigerant in a liquid phase with low pressure passes through the source air-refrigerant heat exchanger 112 working as an evaporator so as to absorb heat from ambient air. Next, the refrigerant is guided to flow into the compressor 111 and then to the heat exchanger 130 as a condenser so that the refrigerant transfers heat to the heat medium of the heat medium circuit 120 in the heat exchanger 130
Implementation Method 2
the refrigerant is guided to flow into the compressor 111
Implementation Method 3
The refrigerant after transferring heat is guided to the expansion valve 113 to result in a decrease in pressure
Data Source
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AI summary
The invention relates to a method for operating a heat pump system and the heat pump system, preferably adopting this method, wherein the operating method comprises steps of determining operating modes of the heat pump system.