Heat Medium Relay Layout for Air Conditioning Pressure Balance

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Solution Overview

Problem

Existing air-conditioning systems face issues with refrigerant leakage, high energy consumption due to long circulation paths, complex construction, high costs, noise, and inefficiency in heat transfer, particularly when dealing with changing volumes of heat media induced by temperature changes.

Innovation Solution

The air-conditioning apparatus incorporates a pressure absorber to manage temperature-induced volumetric changes in heat media, using a pressure equalizing pipe to maintain uniform pressure across passages, reducing the need for multiple expansion tanks and enhancing safety, reliability, and energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a heat medium is circulated through long pipes from an outdoor unit to indoor units, then heating or cooling can be provided to multiple indoor spaces, but the conveyance power and energy consumption markedly increase

Engineering Contradiction:

Improveability to heat or cool multiple indoor spacesVSAvoidconveyance power consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent introduces a heat medium relay unit as an intermediary component between the outdoor unit and indoor units. This relay unit receives heat medium from the outdoor unit and distributes it to multiple indoor units, reducing the circulation distance and conveyance power requirements while maintaining the ability to serve multiple indoor spaces simultaneously

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If four water pipes are arranged to connect each indoor space to an outdoor unit for simultaneous cooling and heating, then arbitrary cooling or heating can be selected in each indoor unit, but the construction complexity and difficulty increase

Engineering Contradiction:

Improveability to select cooling or heating in each indoor unitVSAvoidconstruction ease

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent segments the heat medium circulation system into two separate single-pipe systems: one for cooling and one for heating. Each indoor unit connects to the outdoor unit through a single pipe that can carry either cooling or heating heat medium, eliminating the need for four pipes while maintaining the ability to select cooling or heating in each indoor unit

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If a secondary medium circulating device such as a pump is provided to each indoor unit, then the heat medium can be circulated to each indoor unit, but the system cost increases and noise increases

Engineering Contradiction:

Improveheat medium circulation capabilityVSAvoidsystem cost and noise

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent makes the heat medium relay unit a multi-functional device that performs both the function of a pump (circulating heat medium to multiple indoor units) and the function of a distribution hub (managing separate cooling and heating circuits). This eliminates the need for individual pumps at each indoor unit, reducing system cost and noise while maintaining circulation capability

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution effectively suppresses pressure changes in pipes, prevents damage, and reduces energy consumption by optimizing heat medium flow, resulting in a safer, more reliable, and space-efficient air-conditioning system.

Implementation Method 1

a pressure absorber that absorbs an expansion force, which varies by temperature, of a heat medium and thus is capable of suppressing the pressure change in the pipes that is caused by temperature-induced volumetric change of the heat medium

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

by allowing the heat medium to flow between passages through a pressure equalizing pipe, the differences in volume in each passage that are based on the temperature differences in the heat mediums can be suppressed

Methodology Applied

Scientific EffectPressure equalization through fluid flow: Pressure Gradient

Data Source

PatentEP2492613B1Air conditioning device

Publication Date: 2019.05.01 MITSUBISHI ELECTRIC CORP

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AI summary

A safe, highly reliable air-conditioning apparatus that can save energy is obtained. The air-conditioning apparatus includes indoor units 2 including a plurality of use side heat exchangers 26 that exchange heat between air with which heat is to be exchanged and a heat medium, and a heat medium relay unit 3 having a plurality of heat exchangers related to heat medium 15 that heat or cool the heat medium, a plurality of pumps 21 that deliver the heat medium involved in heating or cooling performed by the plurality of heat exchangers related to heat medium 15 to each passage and circulate the heat medium, and a plurality of heat medium flow switching devices 22 and 23 that perform switching so that the heat medium from a selected passage flows into and flows out of each use side heat exchanger 26; the air-conditioning apparatus further includes an expansion tank 60 that is connected to a passage, alleviates a pressure change caused by a volumetric change of the heat medium, and a pressure equalizing pipe 5c that connects each inlet passage or each outlet passage of the heat medium sending devices.