Split-Refrigerant Air-Conditioning Layout for Leak-Safe Indoor Cooling
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Solution Overview
Problem
Existing air-conditioning systems face challenges with refrigerant leakage, particularly for high-pressure refrigerants like R410A, which have significant global warming coefficients, and natural refrigerants like carbon dioxide, ammonia, and propane, which require stringent leakage control to ensure safety and environmental protection, while also dealing with high energy consumption due to water conveying in chiller systems.
Innovation Solution
An air-conditioning apparatus with a heat source device, a relay unit, and an indoor unit, utilizing a primary refrigerant and a secondary refrigerant like water or brine, where the refrigerant circuit is designed to minimize refrigerant leakage into living spaces by using vertical and horizontal pipelines, and incorporating a relay unit to exchange heat between the primary and secondary refrigerants, reducing the need for large refrigerant quantities and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-pressure refrigerant is conveyed to indoor unit, then cooling or heating function is achieved, but refrigerant filled amount becomes extremely large and leakage risk increases
Solution Approach 1:
The system is divided into two independent refrigerant circuits: a primary refrigerant circuit (using R410A or other high-pressure refrigerants) for heat generation at the heat source device, and a secondary refrigerant circuit (using water or brine) for heat transport to indoor units. This segmentation eliminates the need to convey high-pressure refrigerant through long pipelines to multiple indoor units, thereby dramatically reducing the total refrigerant filled amount and leakage risk while maintaining cooling and heating functions.
2Use of energy by moving object
If heat exchange is performed between refrigerant and water in heat source device, then cooling or heating energy is transferred to indoor unit, but water conveying power becomes extremely large and energy consumption increases
Solution Approach 1:
The system optimizes the parameters of the secondary refrigerant (water or brine) by controlling its temperature and flow rate to match the heating or cooling demands of various indoor units. By adjusting these parameters and using variable speed pumps, the system achieves efficient heat transport with reduced conveying power requirements and lower energy consumption compared to conventional chiller systems.
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 solution effectively suppresses refrigerant leakage into living spaces, enhances safety and reliability, and reduces energy consumption by optimizing refrigerant usage and heat exchange, while allowing for easier installation and control of the air-conditioning system.
Implementation Method 1
a compressor that pressurizes a primary refrigerant used by changing states between a gas phase and a liquid phase or between a supercritical state and a non-supercritical state
Implementation Method 2
a second heat exchanger that is located on an installed floor separated from the heat source device by plural floors and in a space not to be air-conditioned, which is different from the space to be air-conditioned, and exchanges heat between the primary refrigerant and a secondary refrigerant mainly composed of water or brine
Implementation Method 3
a third heat exchanger that exchanges heat between the secondary refrigerant and air in the space to be air-conditioned
Data Source
AI summary
An air-conditioning apparatus in which entry of a refrigerant into a living space is suppressed and measures against refrigerant leakage are taken is provided.An air-conditioning apparatus 100 is provided with a heat source device 1 having a compressor that pressurizes a primary refrigerant, a four-way valve 11 that switches a circulation direction of the primary refrigerant, and a heat-source side heat exchanger 12 connected to the four-way valve 11 and installed outside of a building 9 having a plurality of floors or in a space leading to the outside, a relay unit 3 having an intermediate heat exchanger that is disposed in a space not to be air-conditioned different from the space to be air-conditioned on the installed floor separated from the heat source device 1 by plural floors and exchanges heat between the primary refrigerant and a secondary refrigerant and a pump 21 that conveys the secondary refrigerant, an indoor unit 2 having a use-side heat exchanger 26 that exchanges heat between the secondary refrigerant and air in the space to be air-conditioned, a vertical pipeline that connects the heat source device 1 and the relay unit 3 across the plurality of floors, and a horizontal pipeline that connects the relay unit 3 and the indoor unit 2 to each other from outside a wall dividing the space to be air-conditioned to indoors and outdoors and in which the secondary refrigerant in a liquid phase flows through both of pipelines in sets of at least two pipelines.