Relay Unit Heat-Medium Layout for Simultaneous HVAC Heating and Cooling
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Solution Overview
Problem
Conventional air-conditioning apparatuses for buildings face challenges such as refrigerant leakage, complex installation processes, energy loss, and safety concerns due to the use of flammable refrigerants, particularly when attempting simultaneous cooling and heating operations.
Innovation Solution
An air-conditioning apparatus with a relay unit installed outside the conditioned space, utilizing two heat medium pipes to transfer heating and cooling energy between the outdoor and indoor units, eliminating the need for refrigerant pipes inside the building and reducing refrigerant usage, while ensuring safe operation by minimizing refrigerant concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If refrigerant is circulated to indoor units, then cooling and heating operations can be performed, but refrigerant may leak into the room
Solution Approach 1:
The patent introduces a heat medium (water or antifreeze solution) as an intermediary substance that carries thermal energy between the outdoor unit and indoor units. The refrigerant remains confined to the outdoor unit where it exchanges heat with the heat medium through a heat exchanger, while the heat medium circulates through insulated pipes to indoor units. This mediator approach allows cooling and heating operations without refrigerant leakage into indoor spaces.
2Adaptability or versatility
If simultaneous cooling and heating operations are enabled, then different air-conditioning loads for multiple rooms can be satisfied, but the system becomes more complex
Solution Approach 1:
The patent creates a universal heat medium circulation system that can serve multiple indoor units with different cooling and heating requirements. The outdoor unit functions as a multi-functional heat source/sink that can simultaneously provide cooled or heated heat medium to different indoor units. The system uses a single heat medium circulation loop with flow control valves to distribute thermal energy selectively, enabling simultaneous cooling and heating operations without requiring separate refrigerant circuits for each indoor unit.
3Use of energy by moving object
If flammable refrigerant is used, then efficient heat transfer is achieved, but safety concerns arise
Solution Approach 1:
The patent extracts the refrigerant from the indoor environment and confines it entirely within the outdoor unit. The refrigerant performs its heat transfer function efficiently in the outdoor unit through heat exchange with the heat medium, but never enters the indoor spaces where ignition risks would be concerning. This extraction approach separates the high-efficiency heat transfer function (performed by refrigerant in outdoor unit) from the safety-critical environment (indoor spaces), eliminating ignition risks while preserving thermal efficiency.
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 simultaneous cooling and heating operations with reduced refrigerant usage and enhanced safety by preventing refrigerant leakage into indoor spaces and minimizing the risk of ignition, while simplifying installation and reducing energy losses.
Implementation Method 1
a heat exchanger provided in the outdoor unit... the heat medium is heated or cooled with a heat exchanger
Implementation Method 2
the refrigerant transfers heat to air so as to heat the air or removes heat from the air so as to cool the air
Implementation Method 3
the heat medium is conveyed to the indoor unit located in the region to be air-conditioned... so as to cool or heat the region
Data Source
AI summary
An air-conditioning apparatus is capable of cooling a first heat medium and heating the first heat medium at the same time in a relay unit, and the cooled first heat medium and the heated first heat medium can be separately distributed to a plurality of indoor units. Waste heat of a first refrigerant circuit can be discharged to an outdoor space via a second heat medium and the second refrigerant.