Heat Source Unit Layout for Flammable Low-GWP Refrigerants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Air conditioners using refrigerants with low global warming potential face challenges such as increased refrigerant pressure loss and power consumption due to low densities and large vapor volumes, and the risk of fire from flammable refrigerants, which also necessitate costly leakage detectors.
Innovation Solution
The air conditioner employs a ceiling embedded type heat source unit with refrigeration cycle components downstream from airflow and electric parts upstream, reducing refrigerant pressure loss and eliminating the need for additional leakage detectors by ensuring refrigerant leaks are entrained in airflow and discharged safely, using refrigerants like HFO1234yf, HFO1234ze, or R32 with low global warming potential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If refrigerants with low global warming potential (such as HFO1234yf, HFO1234ze) are used, then the global warming potential is reduced, but the refrigerant pressure loss increases and power consumption increases due to low densities and large vapor volumes
Solution Approach 1:
The patent changes the spatial arrangement of components by positioning the electric part box upstream in the airflow direction, away from the refrigeration cycle components where refrigerant leaks occur. This dimensional repositioning in the airflow field prevents refrigerant from reaching electric parts, eliminating the need for leakage detectors and reducing system complexity while maintaining energy efficiency
2Object-affected harmful factors
If refrigerant leakage detection means is added to detect refrigerant leakage, then the fire risk is reduced, but the device complexity and cost increase
Solution Approach 1:
The patent uses the natural airflow direction within the outdoor unit as a protective mechanism, converting the airflow that could potentially spread refrigerant into a beneficial force that carries leaks away from electric parts. This passive safety approach eliminates the need for active detection systems
Solution Approach 2:
The outdoor unit's own airflow system serves the dual function of cooling the heat exchanger and protecting electric parts from refrigerant leaks. The blower-driven airflow automatically performs the safety function without requiring additional detectors or control 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
This configuration reduces refrigerant pressure loss, lowers compressor power consumption, and avoids the risk of fire by preventing refrigerant contact with electric components, while minimizing the number of costly detectors, resulting in a more efficient and cost-effective air conditioning system.
Implementation Method 1
A blower driven by a motor generates airflow in the case. The refrigeration cycle components in which the refrigerant flows are arranged in the airflow in the case.
Implementation Method 2
ensuring refrigerant leaks are entrained in airflow and discharged safely
Implementation Method 3
a heat exchanger in which the refrigerant flows
Implementation Method 4
Heat exchanger in which the refrigerant flows through it, in the airflow
Implementation Method 5
compressor and an outdoor blower fan are operated... the vapor specific volume of HFO1234yf is 180% of R410A... the refrigerant pressure loss on the low pressure side of the air conditioner increases
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An air conditioner able to avoid the risk of fire and able to have a reduced number of refrigerant leakage detectors while using a refrigerant having a low global warming potential (GWP) is obtained. The air conditioner is provided with a heat source unit (2) configured so as to use a flammable refrigerant having a low global warming potential, and configured by housing inside a case (2a) refrigeration cycle components such as a heat exchanger (22) in which the refrigerant flows, an electric part box (28) in which electric parts and the like are housed, and a blower (24) driven by a motor (24a). Also, airflow is formed by the blower in the case, and the refrigeration cycle components in which the refrigerant flows are arranged in the airflow in the case, and the electric part box and electric parts such as the motor of the blower are arranged upstream from the refrigeration cycle components in the airflow.