Refrigeration system
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Solution Overview
Problem
Conventional refrigeration systems require complex reversible circuits with four-way valves to achieve both heating and cooling functions, which are inefficient and costly.
Innovation Solution
A refrigeration system with a metering device that operates in two modes: one mode with a restricted pressure reduction for cooling and another mode without pressure reduction for heating, utilizing a variable expansion valve or bypass valve to simplify the circuit and eliminate the need for a four-way valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional reversible circuit with four-way valve is used to achieve both heating and cooling functions, then the system can provide both heating and cooling capabilities, but the device complexity and cost increase
Solution Approach 1:
The patent removes the four-way valve from the refrigeration circuit, extracting the complex reversing mechanism while retaining heating and cooling capabilities through alternative means (electronic expansion valve modulation and heat exchanger configuration switching)
Solution Approach 2:
The electronic expansion valve and heat exchangers are designed to perform multiple functions: the electronic expansion valve controls refrigerant flow for both cooling and heating modes, while the heat exchangers can operate as evaporators or condensers depending on the operational mode, eliminating the need for dedicated reversing valves
2Adaptability or versatility
If a four-way valve is used to reverse refrigerant flow for heating and cooling, then both heating and cooling functions are achieved, but the system cost increases
Solution Approach 1:
The patent replaces the expensive four-way valve with more economical components: standard electronic expansion valves, solenoid valves, and electronic controllers that are cheaper to manufacture and install, while achieving the same functional outcome of reversible heating and cooling operations
3Productivity
If the metering device restricts refrigerant flow in both modes, then cooling efficiency is maintained, but the ability to cool the thermal store is reduced
Solution Approach 1:
The electronic expansion valve provides dynamic, variable restriction rather than fixed restriction, allowing the system to optimize refrigerant flow for different operational modes: restricted flow for efficient cooling operation and unrestricted flow for thermal store cooling, achieving both high cooling efficiency and mode flexibility
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 efficiently reverses cooling and heating functions without a four-way valve, leveraging latent heat capacity for extended cooling periods and reducing costs while maintaining efficient temperature control.
Implementation Method 1
The pressure of the refrigerant may be reduced by the metering device in the first mode, and the pressure of the refrigerant may not be reduced by the metering device in the second mode. By reducing the pressure of the refrigerant in the first mode, the temperature of the refrigerant is reduced and cooling may be achieved at the first heat exchanger.
Implementation Method 2
a first heat exchanger for exchanging heat between the refrigerant and a medium
Implementation Method 3
a second heat exchanger for exchanging heat between the refrigerant and a thermal store
Implementation Method 4
the circuit comprising a compressor
Data Source
AI summary
A refrigeration system is described having a circuit around which a refrigerant circulates. The circuit includes a compressor, a metering device, a first heat exchanger for exchanging heat between the refrigerant and a medium, and a second heat exchanger for exchanging heat between the refrigerant and a thermal store. The refrigeration system is operable in a first mode and a second mode. In the first mode, the metering device has a first restriction such that the medium is cooled at the first heat exchanger and the thermal store is heated at the second heat exchanger. In the second mode, the metering device has a second, less restrictive restriction or is bypassed such that the medium is heated at the first heat exchanger and the thermal store is cooled at the second heat exchanger.