Refrigerant Bypass in Subcool Condensers to Cut Heating Pressure Loss
Solution Overview
Problem
Conventional refrigerant cycle devices experience a deterioration in Coefficient of Performance (COP) during the heating operation mode due to increased pressure loss when a subcool condenser is used as the evaporator, which affects the overall efficiency of both cooling and heating modes.
Innovation Solution
Incorporating a refrigerant bypass portion that allows the refrigerant to bypass at least a part of the supercool heat exchange portion during the heating operation mode, reducing pressure loss and improving COP in both modes by controlling the refrigerant flow through a bypass pipe with a control valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a subcool condenser is used as the outdoor heat exchanger in the heating operation mode, then the refrigerant capacity of the evaporator can be increased, but the pressure loss increases and COP deteriorates
Solution Approach 1:
The outdoor heat exchanger is divided into a condensation heat exchange portion and a supercool heat exchange portion. During heating operation, the refrigerant flows only through the condensation portion, bypassing the supercool portion, thereby maintaining refrigerant capacity while reducing pressure loss.
Solution Approach 2:
The refrigerant flow path is dynamically switched between cooling and heating modes. In heating mode, a bypass mechanism allows the refrigerant to selectively flow through only the necessary condensation portion, adapting the flow path to operational requirements and minimizing pressure loss.
2Adaptability or versatility
If the outdoor heat exchanger functions as the evaporator in heating mode, then the utilization side heat exchanger can function as the radiator, but the COP deteriorates due to pressure loss
Solution Approach 1:
The heat exchanger is segmented into functional portions that can be selectively used. The condensation heat exchange portion serves as the evaporator in heating mode, while the supercool portion is bypassed, allowing versatile operation mode switching without unnecessary pressure loss.
Solution Approach 2:
The outdoor heat exchanger is designed to perform multiple functions: condensation in both cooling and heating modes, and supercooling only in cooling mode. This multi-functionality is achieved through selective refrigerant flow paths controlled by four-way valves.
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 enhances the COP in both cooling and heating operation modes by reducing pressure loss and power consumption, ensuring improved efficiency and performance.
Implementation Method 1
a condensation heat exchange portion for condensing the refrigerant
Implementation Method 2
a supercool heat exchange portion for supercooling a saturated liquid phase refrigerant flowing out of the receive portion
Implementation Method 3
an outdoor heat exchanger for exchanging heat between the refrigerant and ambient air
Data Source
AI summary
A subcool condenser having a condensation heat exchange portion, a receive portion and a supercool heat exchange portion is used as an outdoor heat exchanger that functions as a radiator in a cooling operation mode so that COP in the cooling operation mode is increased. In contrast, in a heating operation mode, a refrigerant bypass device that causes the refrigerant to flow so as to bypass the supercool heat exchange portion is provided so that pressure loss generated in the refrigerant flowing through the outdoor heat exchanger is decreased. Thereby, driving force of a compressor can be decreased and COP in the heating operation mode can be improved.