Refrigeration cycle device and liquid heating device having the same
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Solution Overview
Problem
Conventional refrigeration cycle devices face issues with liquid back in the compressor due to direct injection of refrigerant through a supercooling heat exchanger, leading to reliability concerns and difficulty in measuring the degree of superheat.
Innovation Solution
A refrigeration cycle device with a main refrigerant circuit and a bypass refrigerant circuit, including an intermediate heat exchanger, a pre-cooling temperature sensor, and a post-cooling temperature sensor, where the control device calculates the degree of superheat and adjusts the second expanding valve to prevent liquid back by ensuring the refrigerant is adequately heated before injection into the compression chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If refrigerant is directly injected into the compression chamber through the supercooling heat exchanger, then the refrigeration cycle operates with simple structure, but liquid back occurs and compressor reliability deteriorates
Solution Approach 1:
The patent introduces an intermediate chamber as a mediator between the supercooling heat exchanger and the compression chamber. The refrigerant is injected into the intermediate chamber first, where its state can be adjusted, before entering the compression chamber. This intermediary space prevents direct injection of liquid refrigerant into the compression chamber, thereby solving the liquid back problem while maintaining operational simplicity.
2Device complexity
If refrigerant is directly injected into the compression chamber, then the system structure remains simple, but it becomes difficult to measure the degree of superheat of mixed refrigerant
Solution Approach 1:
The intermediate chamber serves as an intermediary space where refrigerant state can be measured before mixing with compression chamber refrigerant. Temperature sensors can be placed in the intermediate chamber to measure the degree of superheat of the injected refrigerant, making measurement feasible without complex system restructuring.
Solution Approach 2:
The patent segments the refrigerant flow path into distinct zones: the supercooling heat exchanger, the intermediate chamber, and the compression chamber. This segmentation allows for separate measurement and control of refrigerant state in each zone, enabling accurate degree of superheat measurement in the intermediate chamber before mixing occurs.
3Duration of action of moving object
If liquid refrigerant is injected into the compression chamber, then the refrigeration cycle maintains continuous operation, but vibration increases and compression mechanism reliability decreases
Solution Approach 1:
The patent applies preliminary action by pre-heating the refrigerant in the supercooling heat exchanger and allowing it to mix with compression chamber refrigerant in the intermediate chamber before final compression. This preliminary mixing and heating ensures the refrigerant is in an appropriate state before entering the compression chamber, preventing liquid back and vibration while maintaining continuous operation.
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 prevents liquid back and enhances the reliability of the compression mechanism by ensuring the refrigerant is properly superheated before compression, reducing vibration and maintaining the refrigerant in a gas state.
Implementation Method 1
the branched refrigerant exchanges heat, in the intermediate heat exchanger, with the refrigerant flowing through the main refrigerant circuit
Implementation Method 2
a pre-cooling temperature sensor for detecting temperature of the refrigerant flowing through the bypass refrigerant circuit located upstream of the intermediate heat exchanger; a post-cooling temperature sensor for detecting temperature of the refrigerant flowing through the bypass refrigerant circuit located downstream of the intermediate heat exchanger
Implementation Method 3
a compression mechanism composed of a compression rotating element
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3
AI summary
A refrigeration cycle device includes a main refrigerant circuit 10, a bypass refrigerant circuit 20, a pre-cooling temperature sensor for detecting temperature of refrigerant flowing through the bypass refrigerant circuit 20 located upstream of an intermediate heat exchanger 13, a post-cooling temperature sensor for detecting temperature of refrigerant flowing through the bypass refrigerant circuit 20 located downstream of the intermediate heat exchanger 13, and a control device 60, wherein the control device 60 calculates a degree of superheat of the refrigerant which merges with the compression rotating element based on temperature data acquired from the pre-cooling temperature sensor 56 and from the post-cooling temperature sensor 58, and when the calculated degree of superheat is lower than a predetermined value, the control device 60 operates to reduce a valve opening degree of the second expanding device 21, and the degree of superheat of refrigerant after it passes through the supercooling heat exchanger is made equal to or higher than the predetermined value. According to this, the present invention provides a reliably refrigeration cycle device and a liquid heating device having the same which prevents liquid back.