Coolant circuit running device and method for operating a coolant circuit running device with a hybrid evaporator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CO2-based refrigeration cycle devices suffer from low efficiency, uneven operating behavior, and the risk of liquid shocks in compressors due to incomplete evaporation, with limited temperature and operational ranges.
Innovation Solution
A refrigeration circuit device with a CO2-based refrigerant and a hybrid evaporator or condenser featuring a tube-in-tube system, where a narrow annular gap between inner and outer tubes optimizes performance, using a water-based coolant like glycol, and optional thermal bridges for enhanced heat transfer, allowing for stable and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional evaporator design is used with CO2 refrigerant, then the refrigeration circuit can operate, but liquid slugs occur in the compressor due to incomplete evaporation
Solution Approach 1:
The patent implements a tube-in-tube heat exchanger configuration where an inner tube containing coolant is nested within an outer tube through which CO2 refrigerant flows. This nested structure increases the heat transfer surface area and improves evaporation completeness, preventing liquid slugs from entering the compressor while maintaining system reliability.
2Use of energy by moving object
If a conventional evaporator design is used with CO2 refrigerant, then the system can operate, but only comparatively low efficiencies can be achieved
Solution Approach 1:
The tube-in-tube configuration with inner and outer tubes creates a compact heat exchanger with enhanced heat transfer surface area. This design reduces temperature differences between refrigerant and coolant, improving thermodynamic efficiency and reducing energy losses in the heat transfer process.
Solution Approach 2:
The patent introduces a radial heat transfer dimension by nesting tubes within tubes, allowing heat exchange to occur not only along the longitudinal axis but also radially through the tube walls. This multi-dimensional heat transfer approach enhances overall heat transfer efficiency and reduces energy losses.
3Stability of the object's composition
If a conventional evaporator design is used with CO2 refrigerant, then the system can operate, but uneven operating behavior occurs
Solution Approach 1:
The nested tube structure provides uniform heat distribution along the length of the heat exchanger, creating consistent evaporation conditions. This design promotes stable and uniform operating behavior by ensuring even heat transfer across the entire refrigerant flow path, eliminating localized hot or cold spots that cause uneven operation.
4Adaptability or versatility
If a conventional evaporator design is used with CO2 refrigerant, then the system can operate, but temperature ranges and operating ranges are comparatively limited
Solution Approach 1:
The tube-in-tube heat exchanger design with adjustable parameters (tube dimensions, coolant flow rate, refrigerant flow rate) provides universal applicability across different temperature ranges and operating conditions. The modular design allows adaptation to various refrigeration applications, expanding the system's versatility and operational range.
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 achieves higher efficiency and operational reliability with reduced temperature differences, preventing compressor damage from liquid shocks and enabling stable, quiet operation with improved heat transfer, allowing for versatile operating modes.
Implementation Method 1
the evaporator and/or the condenser is provided with at least one refrigerant channel and at least one coolant channel running parallel thereto, wherein the evaporator and/or condenser is a coupled pipe-in-pipe system with an inner pipe and an outer pipe surrounding it
Implementation Method 2
a refrigeration circuit device with a CO2-based refrigerant and a hybrid evaporator or condenser featuring a tube-in-tube system
Data Source
Figure 1~2
Figure 3~4
AI summary
Refrigeration circuit device with a refrigerant-flowing refrigeration circuit K comprising at least one compressor, a condenser, an expansion medium and at least one evaporator (1) and a refrigerant circuit thermally coupled to the refrigeration circuit K, comprising a water-based refrigerant or refrigerant mixture, wherein the evaporator (1) and/or the condenser is provided with at least one refrigerant channel and at least one refrigerant channel running parallel thereto, wherein the refrigerant is CO2 and the evaporator (1) and/or the condenser are a coupled tube-in-tube system with an inner tube (2) and an outer tube (3) surrounding it externally, wherein a narrow annular gap (4) is formed between the inner tube (2) and the outer tube (3) in relation to the diameters of the inner tube (2) and the outer tube (3), and wherein the specific volume of the refrigerant is matched to the size of the annular gap (4).