Heat Pump Water Flow Split Control for Target Heating Temperature
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Solution Overview
Problem
In multi-stage compression refrigeration cycles with a fixed capacity ratio, energy consumption efficiency is not adequately increased when heating water to a target temperature, as the capacities of the compressors are fixed and cannot be controlled separately, limiting the ability to optimize the flow rate ratio of water for heating.
Innovation Solution
A heat pump system with a heat pump circuit, heat load circuit, first and second heat exchangers, a flow rate regulation mechanism, and a controller, which regulates the flow rate of fluid through the heat exchangers based on predetermined conditions to optimize energy consumption efficiency, even when the temperature of refrigerant from the low-stage compressor does not meet the heating target temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a multi-stage compression refrigeration cycle with fixed capacity ratio is used, then the compression efficiency is improved, but the energy consumption efficiency cannot be sufficiently increased when heating water to target temperature
Solution Approach 1:
The patent applies dynamics by making the water flow rate adjustable through a flow rate regulation mechanism. Instead of using a fixed flow rate, the system dynamically regulates the flow rate of water passing through the heat exchanger based on operating conditions, allowing optimization of energy consumption efficiency while maintaining the fixed capacity ratio compression system.
Solution Approach 2:
The patent changes the parameter of water flow rate through the heat exchanger. By regulating the flow rate parameter according to predetermined conditions and controller settings, the system optimizes the balance between compression efficiency and energy consumption efficiency for water heating applications.
2Loss of energy
If the flow rate of water for heating is set to half or less of total water amount, then the cycle efficiency is improved, but the energy consumption efficiency is not adequately increased when refrigerant temperature does not meet target temperature
Solution Approach 1:
The patent implements feedback control where the controller monitors the refrigerant temperature and flow rate conditions, then adjusts the flow rate regulation mechanism accordingly. This closed-loop feedback system ensures that the flow rate is optimized based on actual operating conditions, improving energy consumption efficiency when refrigerant temperature varies.
Solution Approach 2:
The system dynamically adjusts the water flow rate through the heat exchanger based on real-time conditions. Rather than using a static flow rate ratio, the flow rate regulation mechanism responds to changing refrigerant temperatures and heating demands, maintaining optimal energy consumption efficiency across varying operating conditions.
3Device complexity
If the capacities of different-stage compressors are fixed with fixed capacity ratio, then the system structure is simplified, but the ability to optimize flow rate ratio for heating is limited
Solution Approach 1:
The patent segments the water flow control into a regulated portion through the heat exchanger and an unregulated portion. The flow rate regulation mechanism specifically controls the flow rate of water passing through the heat exchanger, separating this control function from the overall water distribution system. This allows optimization of heating efficiency without complicating the entire water distribution infrastructure.
Solution Approach 2:
The flow rate regulation mechanism acts as an intermediary component between the fixed capacity ratio compression system and the heating load. This intermediary device enables flow rate optimization for energy efficiency without requiring changes to the compressor capacities or the overall system structure, thus maintaining simplicity while adding adaptability.
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 system achieves higher energy consumption efficiency and reduces damage to heat exchangers by controlling the flow rate to maintain optimal temperature conditions, ensuring efficient heating of water to the target temperature while minimizing energy waste.
Implementation Method 1
The first heat exchanger performs heat exchange between the refrigerant flowing from the discharge side of the low-stage compression mechanism toward the intake side of the high-stage compression mechanism and the fluid flowing through the first passage
Implementation Method 2
The second heat exchanger performs heat exchange between the refrigerant flowing from the high-stage compression mechanism to the expansion mechanism and the fluid flowing through the second passage
Data Source
AI summary
A heat pump system includes a heat pump circuit, a heat load circuit, first and second heat exchangers, a flow rate regulation mechanism and a controller. A first passage connects branching and converging portions of the heat load circuit. A second passage connects the branching and converging portions without converging with the first passage. The first and second heat exchanger perform heat exchange between discharge refrigerant from the low and high stage compression mechanisms and fluid in the first and second passages, respectively. The flow rate regulation mechanism regulates a ratio between flow rates through the first and second passages. The controller controls the flow rate regulation mechanism so that the fluid is allowed to flow to the first heat exchanger when a temperature of refrigerant flowing into the first heat exchanger is lower than a heating target temperature of converged fluid flowing through the heat load circuit.