Heat Pump Pump-Cycle Control for Low-Load Power Saving
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Solution Overview
Problem
Existing heat-pump heat source apparatuses experience high power consumption due to continuous operation of pumps, which impairs energy-saving performance by failing to accurately detect and adjust to changing load conditions.
Innovation Solution
A heat-pump heat source apparatus with a controller that estimates and adjusts the operation of the compressor and pump based on water temperature changes, stopping the pump after a predetermined time to reduce power consumption and improve energy efficiency by optimizing the operation intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the pump operates continuously to accurately detect water temperature changes, then the temperature detection accuracy is improved, but the power consumption increases
Solution Approach 1:
The pump operates periodically rather than continuously. The controller stops the pump after a predetermined time period even when the compressor is still operating, creating periodic on/off cycles that reduce power consumption while maintaining adequate temperature monitoring capability.
Solution Approach 2:
The system performs preliminary temperature detection during the period when the pump is operating, then uses this data to estimate future temperature trends. This allows the pump to be stopped in advance while still maintaining accurate temperature control through predictive algorithms.
2Measurement precision
If the pump operates continuously to monitor load conditions, then the load condition detection accuracy is improved, but the energy-saving performance deteriorates
Solution Approach 1:
The controller uses feedback from temperature sensor readings taken during pump operation to estimate future temperature changes and compressor startup timing. This feedback mechanism allows accurate load condition detection during limited pump operation periods while enabling energy-saving predictions for when the pump can be stopped.
Solution Approach 2:
The system dynamically adjusts pump operation duration based on real-time temperature changes and load conditions. The controller determines the optimal time to stop the pump by analyzing temperature trends, making the operation duration flexible rather than fixed, thereby balancing detection accuracy with energy conservation.
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
The solution reduces power consumption by temporarily stopping the pump when the load is small, allowing for accurate detection of temperature changes and improving energy-saving performance by optimizing compressor operation based on estimated necessary times.
Implementation Method 1
a water heat exchanger
Implementation Method 2
extracts heat from the outdoor air by executing the heat-pump refrigerating cycle
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A controller (20) performs on/off control for the operation of a compressor (1) such that the detected temperature of a water temperature sensor (14) in the on-state of a pump (13) is a preset temperature. The controller (20) estimates a necessary time to the next presumable start of the operation of the compressor (1) based on the change in the detected temperature of the water temperature sensor (14) in a first time after stopping the operation of the compressor (1). The first time after stopping the operation of the compressor (1), the controller (20) stops the operation of the pump (13). The estimated necessary time after stopping the operation of the pump (13), the controller (20) causes the pump (13) to operate for only a second time.