Indoor Unit Blower Start Control in Two-Pipe Air Conditioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing air-conditioning systems for buildings face issues such as refrigerant leakage, inefficient energy use due to long circulation paths, complex and costly constructions, and reduced performance when using non-azeotropic refrigerant mixtures, leading to increased wait times for cooling or heating operations and compromised user comfort.
Innovation Solution
An air-conditioning apparatus with a refrigerant circuit and a heat medium circuit that utilize intermediate heat exchangers for efficient heat exchange, allowing for flexible operation modes and reducing the need for extensive piping, along with a blower device activation strategy that minimizes initial energy consumption and user discomfort during mode transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If refrigerant is circulated to indoor units, then cooling and heating functions are achieved, but refrigerant leakage into rooms occurs
Solution Approach 1:
The patent introduces a heat medium (water or antifreeze solution) as an intermediary substance that carries thermal energy between the outdoor heat source device and indoor units. This heat medium circulates through dedicated pipes without leaking refrigerant, while the refrigerant remains confined to the outdoor unit's heat exchanger system. The heat medium acts as a safe mediator that transfers thermal energy without the hazards of refrigerant leakage into living spaces.
2Adaptability or versatility
If heat medium circulation path is extended to reach indoor units, then cooling and heating are provided, but transport power consumption increases
Solution Approach 1:
The system pre-cools or pre-heats the heat medium in the outdoor heat source device before transporting it to indoor units. By performing the thermal energy transfer in advance at the heat source, the system reduces the energy required for transporting the heat medium through long circulation paths. The heat medium is prepared with the necessary thermal energy before circulation, minimizing ongoing transport power consumption.
3Adaptability or versatility
If four water pipes are connected for waste heat absorption chiller, then cooling and heating can be freely selected, but construction complexity increases
Solution Approach 1:
The patent implements a universal two-pipe system where the same hot water and cold water pipes serve multiple functions for both cooling and heating operations. The system can freely switch between cooling and heating modes by reversing the flow direction or switching the heat source, eliminating the need for separate four-pipe configurations. This multi-functional approach reduces piping complexity while maintaining operational flexibility.
4Productivity
If secondary refrigerant heat exchangers are installed near indoor units, then heat transfer efficiency improves, but refrigerant leakage risk increases
Solution Approach 1:
The patent places heat exchangers near indoor units but uses a heat medium (water or antifreeze) instead of refrigerant in these distributed units. The heat medium serves as a safe intermediary that can be handled without the environmental and health risks associated with refrigerant leakage. The heat exchangers efficiently transfer thermal energy from the circulating heat medium to the indoor air, maintaining high heat transfer efficiency while eliminating refrigerant leakage risks at distributed locations.
5Productivity
If non-azeotropic refrigerant mixture is used, then cooling performance is improved, but wait time for operation increases
Solution Approach 1:
The patent uses a heat medium as an intermediary that decouples the refrigerant cycle from the heat distribution system. This allows the use of optimized refrigerant mixtures in the outdoor heat source device for high cooling performance while the heat medium rapidly distributes thermal energy to indoor units. The intermediary heat medium system reduces wait times by enabling faster thermal response at distributed locations compared to direct refrigerant circulation.
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
The system reduces wait times for cooling and heating operations while maintaining user comfort by optimizing energy use and simplifying construction, addressing the inefficiencies and complexities of previous systems.
Implementation Method 1
The intermediate heat exchanger exchanges heat between the refrigerant and the heat medium
Data Source
AI summary
When starting a cooling operation mode from a non-operating mode, the blower device of the indoor unit from which the start command is originated is operated. When starting a heating operation mode from a non-operating mode, the blower device of the indoor unit from which the start command is originated is operated after the heat medium temperature becomes equal to or greater than a preconfigured temperature.