Heat source unit for refrigeration apparatus including a heat-source-side heat exchanger having a heat exchange region of variable size
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Solution Overview
Problem
Refrigeration apparatuses with heat-source-side heat exchangers face limitations in operating within a narrow temperature range of heat source water, leading to inefficiencies and operational failures at varying load factors and temperatures.
Innovation Solution
A heat source unit with a controller that adjusts the size of the heat exchange region in the heat-source-side heat exchanger based on a differential pressure index value, ensuring a sufficient difference between high and low pressures in the refrigeration cycle, thereby maintaining operational efficiency across a broader temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the heat-source-side heat exchanger operates with a fixed heat exchange region size, then the structure is simple, but the refrigeration apparatus cannot operate within a broad temperature range of heat source water
Solution Approach 1:
The heat exchange region size is made variable through a valve mechanism that dynamically adjusts the flow path of the refrigerant. This allows the heat exchanger to adapt its effective heat exchange area according to operating conditions, enabling operation across a broad temperature range of heat source water while maintaining a relatively simple overall structure.
Solution Approach 2:
The heat exchanger is divided into multiple heat exchange sections that can be selectively activated or deactivated. By controlling which sections are included in the refrigerant flow path, the system can adjust the total heat exchange region size to match varying temperature conditions, resolving the contradiction between adaptability and structural simplicity.
2Productivity
If the heat exchange region size is increased to improve heat exchange capability, then the heat exchange efficiency is improved, but the difference between high pressure and low pressure of the refrigeration cycle becomes too small
Solution Approach 1:
The valve mechanism dynamically adjusts the heat exchange region size based on real-time operating conditions. When the heat source water temperature is low, the system reduces the heat exchange region to maintain sufficient pressure difference. When the temperature is high, it increases the heat exchange region to improve heat exchange capability, thus dynamically balancing these two requirements.
Solution Approach 2:
The system changes the effective heat exchange area parameter according to the heat source water temperature. By adjusting this parameter, the system optimizes the balance between heat exchange capability and pressure difference maintenance, preventing the pressure difference from becoming too small while ensuring adequate heat exchange efficiency.
3Stress or pressure
If the heat exchange region size is decreased to maintain pressure difference, then the pressure difference is maintained, but the heat exchange capability becomes insufficient
Solution Approach 1:
The valve mechanism provides dynamic control of the heat exchange region size, allowing the system to switch between different operational states. In low-temperature conditions, it decreases the heat exchange region to maintain pressure difference. In high-temperature conditions, it increases the heat exchange region to ensure sufficient heat exchange capability, thus dynamically resolving this contradiction.
4Adaptability or versatility
If the refrigeration apparatus is designed for a narrow temperature range, then the system is simpler and more reliable, but it cannot operate at varying load factors and temperatures
Solution Approach 1:
The control system uses a valve mechanism to dynamically adjust the heat exchange region size based on detected operating conditions. This dynamic adjustment capability allows the refrigeration apparatus to adapt to varying load factors and temperatures while maintaining system simplicity and reliability through a relatively straightforward control architecture.
Solution Approach 2:
The control system changes the effective heat exchange area parameter according to detected temperature and load conditions. This parameter adjustment enables the system to operate across a broad temperature range and varying load factors without requiring complex control mechanisms, thus resolving the contradiction between adaptability and system complexity.
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 allows the refrigeration apparatus to operate continuously at any load factor, even with heat source water temperatures outside the conventional range, by dynamically adjusting the heat exchange capacity to maintain optimal pressure differences, thus enhancing operational reliability and efficiency.
Implementation Method 1
the heat-source-side heat exchanger allows a refrigerant in a refrigerant circuit to exchange heat with heat source water
Data Source
AI summary
In an air conditioner which is a refrigeration apparatus, a heat source unit has a heat-source-side heat exchanger in which a refrigerant exchanges heat with heat source water. The heat-source-side heat exchanger includes a plurality of heat exchange sections, and has a heat exchange region whose size can be adjusted through changing the number of heat exchange sections into which the refrigerant flows. The heat source unit has a controller which can adjust the size of the heat exchange region of the heat-source-side heat exchanger based on a differential pressure index value. This can broaden the temperature range of the heat source water within which the heat source unit of the refrigeration apparatus is operable.