Relay Unit Flow Switching for Low-Leakage Air Conditioning
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Solution Overview
Problem
Existing air-conditioning systems face issues such as refrigerant leakage, high energy consumption due to long heat medium circuits, complex configurations, and increased costs and noise from multiple pumps, as well as inefficiencies in heat exchanger designs that limit indoor unit capacity and ease of construction.
Innovation Solution
An air-conditioning apparatus with a relay unit connected by two refrigerant pipes and two heat medium pipes, featuring adjustable flow switching devices that eliminate the need for separate heat medium flow control devices, reducing the number of components and enhancing energy efficiency and construction ease.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If refrigerant is made to circulate through indoor units, then heat exchange efficiency is improved, but refrigerant leakage risk increases
Solution Approach 1:
The system is divided into two separate circulation loops: a refrigerant loop (outdoor unit to relay unit) and a heat medium loop (relay unit to indoor units). This segmentation allows the refrigerant to perform heat exchange functions without directly entering indoor units, thereby maintaining heat exchange efficiency while eliminating leakage risks in occupied spaces.
2Adaptability or versatility
If heat medium circuit length is increased to connect outdoor unit and indoor units, then system coverage is improved, but energy consumption increases
Solution Approach 1:
A relay unit is introduced as an intermediary component between the outdoor unit and indoor units. The relay unit receives refrigerant from the outdoor unit, performs heat exchange with heat medium in its heat exchanger, and then distributes the heat medium to multiple indoor units. This intermediary approach allows extended system coverage while minimizing heat medium circulation distance and energy consumption.
3Adaptability or versatility
If multiple pumps are provided for each indoor unit, then heat medium distribution flexibility is improved, but device complexity and cost increase
Solution Approach 1:
Multiple pump functions are merged into a single relay unit. The relay unit contains one or more pumps that collectively handle heat medium circulation to all indoor units, replacing the need for individual pumps at each indoor unit location. This consolidation maintains distribution flexibility while significantly reducing device complexity and cost.
4Measurement precision
If separate heat medium flow control devices are provided for each indoor unit, then flow control precision is improved, but device complexity increases
Solution Approach 1:
The flow control mechanism is made dynamic and integrated within the relay unit. The relay unit incorporates flow control valves or adjustable passages that can dynamically regulate heat medium flow distribution to different indoor units based on their individual requirements. This dynamic control system achieves precise flow management without requiring separate static control devices at each indoor unit.
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 minimizes refrigerant leakage, reduces energy consumption, simplifies construction, maximizes indoor unit capacity, and decreases noise and maintenance costs by integrating pumps within the relay unit, while maintaining efficient operation modes.
Implementation Method 1
a heat exchanger for a primary refrigerant and a secondary refrigerant is provided near each of indoor units, and the secondary refrigerant is transported to the indoor units
Implementation Method 2
A refrigerant that circulates through a refrigerant circuit of such an air-conditioning apparatus transfers its heat to (or receives heat from) air supplied to heat exchangers included in the indoor units
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A valve body E included in each of heat medium flow switching devices 32 and 33 has an open portion E1. When the length from a connection between a first passage pipe D1 and a third passage pipe D3 to a connection between a second passage pipe D2 and the third passage pipe D3 is defined as a casing passage width I, a valve body passage width width H of the open portion E1 in a direction substantially perpendicular to the axis of the valve body E is smaller than the casing passage width I.