Dual Refrigerant Circuit Apparatus for Switchable Cycle Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dual refrigeration cycle apparatuses face inefficiencies in switching between dual and single cycle operations, particularly in handling varying thermal loads and maintaining operational efficiency with different refrigerant pressures, which affects the global warming potential and ozone depletion potential.
Innovation Solution
A refrigeration cycle apparatus with a first refrigerant circuit using a low-pressure refrigerant (≤1.2 MPa at 30°C) and a second refrigerant circuit using a high-pressure refrigerant (≥1.5 MPa at 30°C), allowing for switchable dual and single cycle operations, with a cascade heat exchanger for efficient heat exchange, and separate outdoor heat exchangers to prevent cross-heating and optimize refrigerant performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a dual refrigeration cycle apparatus uses both heat-source side and utilization-side refrigerant circuits simultaneously, then heating capacity and thermal load processing efficiency are improved, but device complexity and operational switching difficulty increase
Solution Approach 1:
The patent implements dynamic operational modes that allow the system to switch between dual-cycle and single-cycle operations based on thermal load conditions. The control system dynamically adjusts which refrigerant circuit (heat-source side or utilization-side) is active, enabling the apparatus to adapt its complexity level to match the required heating capacity and thermal processing needs.
2Object-affected harmful factors
If different pressure refrigerants are used in separate circuits, then global warming potential and ozone depletion potential are optimized, but heat exchange efficiency and thermal load handling capability deteriorate
Solution Approach 1:
The cascade heat exchanger serves as an intermediary device that enables efficient heat exchange between refrigerants of different pressures. The heat-source side refrigerant circuit (using high-pressure refrigerant) and utilization-side refrigerant circuit (using low-pressure refrigerant) are thermally coupled through this cascade heat exchanger, allowing thermal energy transfer while maintaining the pressure differential necessary for environmental optimization.
3Loss of energy
If cascade heat exchanger is used for heat exchange between refrigerants, then heat exchange efficiency is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The cascade heat exchanger is segmented into distinct heat exchange zones that handle different refrigerant pressure levels separately. This segmentation allows each zone to be optimized for its specific pressure range while maintaining overall manufacturing feasibility. The heat-source side and utilization-side circuits are physically separated but thermally coupled, reducing manufacturing complexity compared to a fully integrated high-pressure system.
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
Enables efficient processing of thermal loads by optimizing refrigerant pressure and global warming potential, reducing operating costs and environmental impact while maintaining high heating capacity during high-load conditions and minimizing energy loss during low-load operations.
Implementation Method 1
the first refrigerant circuit and the second refrigerant circuit are simultaneously operated to exchange heat between the first refrigerant and the second refrigerant
Data Source
AI summary
A refrigeration cycle apparatus includes a first refrigerant circuit and a second refrigerant circuit so as to improve the efficiency of operations. A first refrigerant circuit using a first refrigerant having a pressure of 1.2 MPa or less at 30° C. and a second refrigerant circuit using a second refrigerant having a pressure of 1.5 MPa or more at 30° C. are provided, and a dual cycle operation in which the first refrigerant circuit and the second refrigerant circuit are simultaneously operated to exchange heat between the first refrigerant and the second refrigerant and a single cycle operation in which the first refrigerant circuit is operated without operating the second refrigerant circuit to perform a cooling operation or heating operation are enabled in a switchable manner.