Heat-Medium Air Conditioner Heating During Defrost
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Solution Overview
Problem
Conventional air-conditioning systems experience efficiency losses during defrosting operations due to direct refrigerant circulation, leading to lowered indoor temperatures and increased energy consumption, as they cannot supply heating energy effectively while defrosting and have high pump power requirements.
Innovation Solution
The air-conditioning apparatus incorporates intermediate heat exchangers and a separate heat medium circulation circuit, allowing for continuous heating during defrosting by switching the four-way valve to introduce high-temperature refrigerant into the heat source side heat exchanger and using a pump to circulate the heat medium for heating, thereby separating the refrigeration cycle and heat medium circulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a refrigerant is circulated directly in an indoor unit during defrosting operation, then heating energy can be supplied to the indoor unit, but the room temperature lowers and system efficiency deteriorates
Solution Approach 1:
The patent divides the heat exchanger into two separate components: a heat source side heat exchanger (outdoors) and a use side heat exchanger (indoor). This segmentation allows the refrigerant to exchange heat with a heat medium outdoors, which then circulates to provide heating indoors, resolving the contradiction between maintaining indoor temperature and preserving system efficiency during defrosting operation.
Solution Approach 2:
The patent introduces a heat medium (water or antifreeze solution) as an intermediary between the refrigerant and the indoor heating system. The heat medium absorbs heat from the refrigerant at the heat source side heat exchanger and transports it to the use side heat exchanger, enabling efficient heat transfer while maintaining indoor temperature during defrosting without direct refrigerant circulation indoors.
2Temperature
If a chiller performs heat exchange between refrigerant and water outdoors, then heating energy can be supplied during defrosting, but system efficiency deteriorates due to large carrying power of the pump
Solution Approach 1:
The patent changes the operational parameters of the pump by separating the heat exchange location from the heating delivery location. The heat medium circulation system is designed to operate at optimized flow rates and temperatures, reducing the pump's energy consumption while still delivering sufficient heating energy to the indoor unit during defrosting operation.
3Use of energy by moving object
If the heat source side heat exchanger and use side heat exchanger are separately formed and disposed at separate locations, then carrying power of heat medium can be reduced, but device complexity increases
Solution Approach 1:
The patent designs the heat medium circulation circuit to serve multiple functions: it transports heat from the heat source side heat exchanger to the use side heat exchanger during normal operation, and continues to circulate heat medium during defrosting operation to maintain indoor heating. This multi-functionality justifies the additional system components by providing versatile operational capabilities.
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 configuration enables continuous heating during defrosting, reduces the power needed for heat medium circulation, and improves system efficiency, contributing to energy savings by maintaining indoor temperatures and optimizing energy usage.
Implementation Method 1
introduce a high-temperature high-pressure refrigerant into the heat source side heat exchanger
Implementation Method 2
heat source side heat exchanger... for heating and cooling a heat medium that exchanges heat between a refrigerant and the heat medium
Implementation Method 3
a heat medium circulation circuit in which a heat medium side flow path of the intermediate heat exchanger, a pump, and a use side heat exchanger are connected via piping through which the heat medium flows
Implementation Method 4
intermediate heat exchangers for heating and cooling a heat medium that exchanges heat between a refrigerant and the heat medium
Data Source
Figure 1
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AI summary
In an air-conditioning apparatus, a heat source side heat exchanger 12, intermediate heat exchangers 15a and 15b, and use side heat exchangers 26a to 26d are separately formed and adapted to be disposed at separate locations, respectively. There are provided a defrosting operation function to melt frost attached around the heat source side heat exchanger 12, and a heating function during defrosting operation that drives a pump 21a to circulate a heat medium and supply heating energy to the use side heat exchangers 26a to 26d in need of heating to perform heating operation. The defrosting operation function can be executed by switching a four-way valve 11 to cooling side to introduce a high-temperature high-pressure refrigerant flowed out of the compressor 10 into the heat source side heat exchanger 12.