Refrigeration System Defrosting via Facility Heat Exchanger Evaporation
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Solution Overview
Problem
Existing refrigeration systems face challenges in efficiently performing defrosting operations without reducing heating capacity, often requiring additional energy sources like electric heaters and complicating the refrigeration circuit configuration.
Innovation Solution
A refrigeration system with a control unit that switches refrigerant flow paths to utilize the refrigeration-facility heat exchanger as an evaporator during outdoor defrosting, blocking indoor heat exchanger inflow, and using warm refrigerant for defrosting, thereby conserving energy and maintaining heating capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the indoor heat exchanger is used as an evaporator during outdoor defrosting operation, then the outdoor heat exchanger can be defrosted, but the heating capacity decreases
Solution Approach 1:
The system separates the defrosting function from the heating function by introducing a dedicated defrosting heat exchanger. During outdoor defrosting operation, the refrigerant flows through the defrosting heat exchanger instead of the indoor heat exchanger, allowing the outdoor heat exchanger to be defrosted while the indoor heat exchanger continues to provide heating capacity.
Solution Approach 2:
The defrosting heat exchanger acts as an intermediary component that enables defrosting operation without affecting the heating function. It temporarily receives the refrigerant flow during defrosting cycles, serving as a mediator between the compressor and the indoor heat exchanger, thus preventing direct conflict between defrosting and heating functions.
2Reliability
If electric heaters are used for defrosting, then defrosting can be performed, but energy efficiency decreases
Solution Approach 1:
The system uses the refrigerant itself, which is already present in the system and contains thermal energy, to perform the defrosting function. The refrigerant absorbs heat from the outdoor heat exchanger during evaporation, effectively defrosting it without requiring external energy sources like electric heaters. This self-service approach maintains high energy efficiency.
Solution Approach 2:
The system utilizes the phase transition of the refrigerant from liquid to vapor in the defrosting heat exchanger. During this evaporation process, the refrigerant absorbs latent heat from the outdoor heat exchanger, providing efficient defrosting. This phase transition mechanism is more energy-efficient than electric heating as it leverages the thermodynamic properties of the refrigerant.
3Reliability
If additional defrosting components are added to the refrigeration circuit, then defrosting capability is improved, but device complexity increases
Solution Approach 1:
The defrosting heat exchanger is designed to serve multiple functions: it acts as an evaporator during defrosting operations and can function as part of the heating or cooling circuit during normal operations. This multi-functionality reduces the need for entirely separate dedicated defrosting components, thereby limiting the increase in device complexity while maintaining improved defrosting capability.
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 defrosts outdoor units while preventing a decrease in heating capacity, improving energy efficiency by eliminating the need for electric heaters and simplifying the refrigeration circuit configuration.
Implementation Method 1
operates the refrigeration cycle circuit using the refrigeration-facility heat exchanger as an evaporator
Implementation Method 2
using the outdoor heat exchanger as a gas cooler or a radiator
Implementation Method 3
the control unit blocks an inflow of the refrigerant to the indoor heat exchanger during an outdoor defrosting operation
Implementation Method 4
a switching mechanism that switches a flow path of a refrigerant according to control of the control unit
Data Source
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AI summary
The present disclosure provides a refrigeration system capable of efficiently executing a defrosting operation while preventing a decrease in heating capacity. The refrigeration system according to the present disclosure includes: a refrigeration cycle circuit that connects an outdoor unit including a compressor and an outdoor heat exchanger, an indoor unit including an indoor heat exchanger, and a refrigeration-facility unit including a refrigeration-facility heat exchanger; and a control unit, the refrigeration cycle circuit includes a switching mechanism that switches a flow path of a refrigerant according to control of the control unit, and the control unit blocks an inflow of the refrigerant to the indoor heat exchanger during an outdoor defrosting operation for defrosting the outdoor heat exchanger, and operates the refrigeration cycle circuit using the refrigeration-facility heat exchanger as an evaporator and the outdoor heat exchanger as a gas cooler or a radiator.