Heat Pump Flow Valve Control for Multi-Unit Temperature Efficiency
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Solution Overview
Problem
Conventional heat pump systems with multiple usage units connected to a single heat source unit operate inefficiently as they constantly maintain the minimum water temperature, leading to unnecessary inefficiency.
Innovation Solution
A heat pump system with a variable-capacity compressor, adjustable flow rate valves, and a temperature decision unit that optimizes the evaporation temperature of refrigerant in each usage unit to supply water at optimal temperatures, preventing constant operation at the minimum water temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the system constantly operates at the minimum water temperature predicted among all usage units, then all usage units can receive water at the required temperature, but the operating efficiency decreases more than necessary
Solution Approach 1:
The patent segments the temperature control for each usage unit by introducing individual flow rate adjustment valves (42a, 42b) for each usage-side heat exchanger (41a, 41b). This allows each usage unit to independently adjust its refrigerant flow rate to achieve its optimal evaporation temperature, rather than all units operating at a single minimum temperature. The segmentation enables differentiated temperature management while maintaining system-wide efficiency.
Solution Approach 2:
The patent implements dynamic temperature control by allowing the evaporation temperature to vary for each usage unit based on its specific requirements. The operating capacity controller (12b) dynamically adjusts the compressor capacity, and the opening degree controller (192a, 192b) dynamically adjusts individual flow rate adjustment valves, enabling the system to adapt temperatures in real-time rather than maintaining a static minimum temperature across all units.
2Adaptability or versatility
If the evaporation temperature is lowered to meet the minimum water temperature requirement, then all usage units can be served, but the compressor operates at lower efficiency
Solution Approach 1:
The system segments the refrigerant flow control for each usage unit through individual flow rate adjustment valves (42a, 42b), allowing each usage-side heat exchanger (41a, 41b) to operate at its own optimal evaporation temperature. This segmentation enables the compressor to maintain higher overall efficiency while still meeting the temperature requirements of all usage units, as each unit can operate independently at its most efficient temperature point.
Solution Approach 2:
The patent changes the operating parameters (evaporation temperature and refrigerant flow rate) for each usage unit individually. The temperature decision unit (191a, 191b) calculates optimal evaporation temperatures based on each usage unit's specific water temperature requirements, and the opening degree controller adjusts the flow rate adjustment valves to achieve these parameter changes, allowing the compressor to operate more efficiently across different temperature conditions.
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 allows for efficient operation by adjusting refrigerant flow rates and pump capacities to ensure each usage unit receives water at the optimal temperature, preventing unnecessary inefficiency and optimizing temperature control.
Implementation Method 1
The compressor is a variable-capacity-type compressor for compressing refrigerant
Implementation Method 2
The heat source-side heat exchanger is capable of functioning as a radiator of refrigerant
Implementation Method 3
The usage-side heat exchangers function as evaporators of refrigerant and can cool an aqueous medium
Implementation Method 4
The usage-side heat exchangers function as evaporators of refrigerant
Data Source
AI summary
A heat source unit has a capacity-variable heat source-side compressor and a heat source-side heat exchanger which functions as a radiator of refrigerant. Usage units are connected to the heat source unit and have usage-side heat exchangers, respectively, which function as evaporators of refrigerant and cool an aqueous medium. An operating capacity controller controls the capacity of the heat source-side compressor so that evaporation temperature of refrigerant of each of the usage-side heat exchangers reaches a first target evaporation temperature. A decision unit calculates second target evaporation temperatures at which outlet temperatures of the aqueous medium in the usage-side heat exchangers of the respective operating usage units reach predetermined set temperatures, and decides a minimum value of the second target evaporation temperatures as the first target evaporation temperature.