Cascade Refrigerant Piping with Reduced Diameter for Oil Return
Solution Overview
Problem
In refrigerant cycle systems with cascade heat exchangers, the flow speed of refrigerant in the secondary-side cycle is typically slow, leading to difficulties in the return of refrigerating-machine oil to the compressor.
Innovation Solution
The system incorporates smaller pipe diameters for the secondary-side connection pipes compared to the primary-side pipes, specifically for the gas and liquid connection pipes, to increase refrigerant flow speed and facilitate the return of refrigerating-machine oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a cascade heat exchanger is introduced to constitute a dual refrigerant cycle, then heat exchange efficiency is improved, but refrigerant flow speed becomes slow
Solution Approach 1:
The patent changes the physical parameter of pipe diameter in the secondary-side cycle to a smaller value, which directly increases refrigerant flow speed while maintaining the heat exchange function of the cascade heat exchanger
2Device complexity
If refrigerant flow speed is slow in the secondary-side cycle, then system complexity is reduced, but refrigerating-machine oil return to compressor becomes difficult
Solution Approach 1:
The patent modifies the pipe diameter parameter in the secondary-side cycle to increase flow speed, which ensures proper refrigerating-machine oil return to the compressor without adding complex auxiliary 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 enhances the flow speed of refrigerant in the secondary-side cycle, ensuring easier return of refrigerating-machine oil to the compressor, thereby improving the overall efficiency of the refrigerant cycle system.
Implementation Method 1
a cascade heat exchanger that exchanges heat between the first refrigerant and the second refrigerant
Data Source
AI summary
A refrigerant cycle system includes a primary-side cycle that circulates a first refrigerant, a secondary-side cycle that circulates a second refrigerant, and a cascade heat exchanger that exchanges heat between the first refrigerant and the second refrigerant. The primary-side cycle includes a primary-side connection pipe. The secondary-side cycle includes a secondary-side connection pipe. The primary-side connection pipe includes a primary-side gas connection pipe and a primary-side liquid connection pipe. The secondary-side connection pipe includes a secondary-side gas connection pipe and a secondary-side liquid connection pipe. The pipe diameter of the secondary-side gas connection pipe is smaller than the pipe diameter of the primary-side gas connection pipe, or the pipe diameter of the secondary-side liquid connection pipe is smaller than the pipe diameter of the primary-side liquid connection pipe.