Relay Unit HVAC Layout to Isolate Refrigerant From Indoor Units
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Solution Overview
Problem
Existing air-conditioning apparatuses for buildings face issues with refrigerant leakage into indoor spaces, high energy consumption due to long circulation paths, poor construction ease, high costs, and noise, especially when multiple indoor units are connected, and inefficient energy use due to complex piping configurations.
Innovation Solution
The air-conditioning apparatus features a refrigerant circuit and a heat medium circuit with a relay unit that separates the outdoor and indoor units, using a compressor, heat exchangers, expansion devices, and pumps to manage refrigerant and heat medium flow efficiently, reducing pipe length and complexity, and allowing for mixed cooling and heating operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If refrigerant is circulated up to indoor unit, then cooling and heating can be achieved, but refrigerant may leak into indoor space
Solution Approach 1:
The system is divided into outdoor unit, relay unit, and indoor unit with separate refrigerant and heat medium circuits. The refrigerant circuit is confined to outdoor and relay units, while heat medium circulates between relay and indoor units, segmenting the harmful refrigerant from indoor spaces.
Solution Approach 2:
Heat medium acts as an intermediary substance between the refrigerant circuit and the indoor units. The refrigerant exchanges heat with the heat medium in the relay unit, and the heat medium then delivers thermal energy to indoor units, preventing direct refrigerant contact with indoor spaces.
2Adaptability or versatility
If heat medium circulation path is made long to connect outdoor unit to indoor units, then heating or cooling can be supplied, but energy consumption increases
Solution Approach 1:
The relay unit serves as an intermediary hub that receives refrigerant from the outdoor unit and distributes heat medium to multiple indoor units. This centralized approach consolidates the circulation path, reducing total pipe length compared to direct connections from outdoor unit to each indoor unit.
Solution Approach 2:
Multiple indoor units are merged into a single circulation system through the relay unit. The heat medium circuit consolidates distribution paths, allowing efficient serving of multiple zones through shared piping rather than individual dedicated circuits.
3Adaptability or versatility
If four pipes are arranged to connect outdoor unit to indoor units for simultaneous cooling and heating, then flexible temperature control is achieved, but construction ease deteriorates
Solution Approach 1:
The system segments cooling and heating functions into separate heat medium circuits within the relay unit. Each circuit can be independently controlled and optimized, allowing flexible temperature control while using separate pipe paths that are easier to install than integrated four-pipe systems.
Solution Approach 2:
The relay unit acts as an intermediary that provides flexible temperature control through its internal circuit configuration. The heat medium circuits within the relay unit enable simultaneous cooling and heating delivery to different indoor units without requiring complex four-pipe connections at each indoor location.
4Adaptability or versatility
If secondary medium circulating means is provided in each indoor unit, then heat exchange can be performed locally, but cost and noise increase
Solution Approach 1:
The secondary medium circulating means (pump) is extracted from the indoor units and relocated to the relay unit. This centralizes the pumping function, eliminating the need for expensive and noisy pumps in each indoor unit while maintaining local heat exchange capability through the heat medium circuit.
Solution Approach 2:
The circulating means are merged into a single location at the relay unit, serving all indoor units through the heat medium circuit. This consolidation reduces overall system cost by eliminating duplicate pumps and reduces noise by centralizing the mechanical component in a less sensitive location.
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 enhances safety, reduces energy consumption, simplifies construction, and improves energy efficiency by minimizing pipe length and complexity, while ensuring safe and efficient operation across multiple indoor units.
Implementation Method 1
a compressor (10)
Implementation Method 2
heat exchangers related to heat medium (15a, 15b)
Implementation Method 3
expansion devices (16a, 16b)
Implementation Method 4
pumps (21a, 21b)
Data Source
AI summary
To provide an air-conditioning apparatus which achieves improvement of safety and further achieves saving of energy without circulating a refrigerant in or near an indoor unit. The air-conditioning apparatus includes one expansion device disposed on an outlet side of a heat exchanger related to the heat medium on the heating side. Another expansion device is disposed on an inlet side of a heat exchanger related to the heat medium on the cooling side such that the expansion devices are directly connected through a connecting pipe.