Single-Pipe Air Conditioning for Stable Multi-Unit Mode Switching
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Solution Overview
Problem
Existing air-conditioning apparatuses face complications in connecting heat medium pipes, leading to complex connections and temperature fluctuations when switching between cooling and heating operations, especially when some indoor units are in a stop state or changing operation modes, affecting air output temperatures in other units.
Innovation Solution
An air-conditioning apparatus with a heat medium flow path switching device and a flow rate adjusting unit allows each indoor unit to be connected through a single heat medium path, controlling the flow rate to suppress temperature changes and maintain consistent air output temperatures during operation mode changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If each indoor unit is connected through separate hot water pipes and cold water pipes to perform individual cooling and heating operations, then each indoor unit can independently perform cooling and heating operations, but the pipe connection becomes complicated
Solution Approach 1:
The patent merges the separate hot water pipes and cold water pipes into a single heat medium pipe that carries heat medium at different temperatures. The heat source unit heats the heat medium, and through flow rate adjusting units, the temperature of the heat medium is controlled to satisfy both heating and cooling requirements, thereby eliminating the need for separate pipe systems while maintaining individual operational capability of each indoor unit.
Solution Approach 2:
The single heat medium pipe system is designed to serve multiple functions: it can supply heated heat medium for cooling operations and cooled heat medium for heating operations to different indoor units simultaneously. The flow rate adjusting units enable the system to adaptively control heat medium temperature and flow distribution, making the same pipe infrastructure universally applicable for both heating and cooling functions.
2Device complexity
If a use side heat exchanger in stop state is started, then the heat medium pipes connected thereto may cause temperature fluctuations in other operating indoor units, but maintaining single heat medium path simplifies connection
Solution Approach 1:
The flow rate adjusting units are configured to detect when an indoor unit is about to switch from stop state to operation state, and proactively adjust the heat medium flow rate before the switch occurs. This preliminary action prevents temperature fluctuations in other operating indoor units by ensuring smooth transition of heat medium supply, thereby maintaining air output temperature stability while keeping the pipe system simple.
Solution Approach 2:
The system employs dynamic flow rate adjustment through the flow rate adjusting units that continuously monitor and adapt heat medium flow rates based on the operational state of each indoor unit. When an indoor unit switches operation mode or starts/stops, the flow rate adjusting units dynamically modify the heat medium distribution to maintain stable temperatures in other units, transforming a potentially unstable single-pipe system into a dynamically balanced system.
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 simultaneous cooling and heating operations while minimizing changes in air output temperature across other indoor units, improving operational efficiency and reducing temperature fluctuations.
Implementation Method 1
a heat source unit 1, in which a heat medium, e.g., water, is heated by an intermediate heat exchanger 15a
Implementation Method 2
a heat source unit 1, in which a heat medium, e.g., water, is heated or cooled by an intermediate heat exchanger 15a
Implementation Method 3
a flow rate adjusting unit 25 that controls a flow rate of the heat medium flowing into the indoor units 2
Data Source
AI summary
Use side heat exchangers, an intermediate heat exchanger that heats a heat medium flowing to the use side heat exchangers, an intermediate heat exchanger that cools the heat medium flowing to the use side heat exchangers, three-way valves that switch between a flow path connecting the intermediate heat exchanger to the use side heat exchangers and a flow path connecting the intermediate heat exchanger to the use side heat exchangers, and three-way valves and bypasses that control the flow rate of the heat medium flowing into the use side heat exchangers are included. When at least one of the use side heat exchangers is switched from a stop state to an operation state or switched to another operation mode, the flow rate of the heat medium flowing into this use side heat exchanger is suppressed, and a change in air output temperature in the use side heat exchangers other than this use side heat exchanger is suppressed.