Control device for heat-pump-using system, and heat-pump-using system provided with same
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Solution Overview
Problem
Existing heat pump systems experience fluctuations in room temperature due to changes in pump rotation speed and flow rate, leading to reduced comfortability.
Innovation Solution
A controller for a heat pump system that adjusts the circulation pump's rotation speed using a correction coefficient based on the circulation flow rate, stabilizing the proportional coefficient to minimize dead time changes and maintain consistent room temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the circulation pump's rotation speed is made variable to optimize heat pump system performance, then energy efficiency is improved, but dead time changes with flow rate causing room temperature fluctuations and reduced comfortability
Solution Approach 1:
The invention applies dynamics by making the proportional coefficient dynamic rather than fixed. The proportional coefficient is adjusted according to the circulation flow rate, allowing the control system to adapt to changing dead time conditions while maintaining stable room temperature control despite variable pump operation
Solution Approach 2:
The invention changes the parameter of the proportional coefficient based on the circulation flow rate. By modifying this control parameter dynamically, the system compensates for dead time variations caused by flow rate changes, resolving the contradiction between energy efficiency and temperature stability
2Power
If the circulation pump operates at variable rotation speeds to fine-tune heat amount, then energy efficiency is improved, but temperature vibrations occur leading to reduced comfortability
Solution Approach 1:
The invention uses feedback control where the proportional coefficient is adjusted based on actual circulation flow rate measurements. This feedback mechanism ensures that temperature control remains stable even when the pump operates at variable speeds for precise heat amount regulation
Solution Approach 2:
The proportional coefficient is made dynamic and adapts to the current operating conditions. This dynamic adjustment prevents temperature vibrations that would otherwise occur during variable speed pump operation, maintaining both control precision and stability
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 effectively reduces room temperature fluctuations, enhancing comfortability and energy efficiency by allowing the circulation pump to operate within a wider range and fine-tuning heat amount changes.
Implementation Method 1
an intermediate heat exchanger in which the first heat medium and the second heat medium exchange heat
Implementation Method 2
an indoor heat exchanger in which the second heat medium and the indoor air exchange heat
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system control device 4 includes a room temperature control unit 18 that generates a heat amount command based on a room temperature and a set room temperature, a frequency command generation unit 19 that generates a frequency command based on the heat amount command, a circulation temperature command generation unit 21 that generates a circulation temperature command based on the heat amount command, a circulation temperature control unit 21 that generates a rotation speed command by feedback control by using at least a proportional coefficient based on circulation temperature and the circulation temperature command, and a correction coefficient generation unit 22 that generates a correction coefficient based on a circulation flow rate of a second heat medium and a preset circulation flow rate reference value. The circulation temperature control unit 21 calculates a proportional coefficient by multiplying a preset proportional coefficient reference value by the correction coefficient. The correction coefficient generation unit 22 generates the correction coefficient such that when the circulation flow rate increases beyond the circulation flow rate reference value, the proportional coefficient increases beyond the proportional coefficient reference value, while when the circulation flow rate decreases beyond the circulation flow rate reference value, the proportional coefficient decreases beyond the proportional coefficient reference value.