Dual Heat Exchanger Refrigeration Loop for Compressor Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional direct expansion refrigeration systems face inefficiencies and damage risks due to temperature and pressure fluctuations, leading to high energy consumption and carbon footprint, with limited improvements in efficiency over the past decade.
Innovation Solution
The introduction of an internal hydrothermal cooling loop with a fluid pump and dual heat exchangers, where a serpentine pipe in a tank with antifreeze fluid cools the refrigerant before compression and a coaxial pipe setup cools the compressed refrigerant, moderated by sensors to regulate the system based on ambient temperature and pressure thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional direct expansion refrigeration system is used, then system structure is simple, but energy efficiency is low and carbon footprint is high
Solution Approach 1:
The patent implements a nested heat exchanger configuration where the evaporator is positioned inside the condenser, creating a compact integrated structure. The expansion device is further nested within the evaporator, and the compressor is housed within the expansion device. This nesting arrangement improves energy efficiency by reducing thermal losses and compacting the system without significantly increasing structural complexity
Solution Approach 2:
The patent combines multiple heat exchange functions into a single integrated structure where the evaporator and condenser share a common thermal environment. The hydrothermal cooling loop merges the cooling and heating cycles, allowing heat recovered from the condenser to pre-cool the refrigerant before it enters the evaporator, thereby improving overall energy efficiency
2Reliability
If expansion valve regulates evaporator flow rate, then superheat is maintained, but compressor may be damaged by liquid refrigerant or overheating
Solution Approach 1:
The patent incorporates a suction line heat exchanger that pre-cools the refrigerant before it enters the compressor, and an discharge line heat exchanger that pre-heats the refrigerant after compression. These preliminary thermal treatments prevent liquid refrigerant from entering the compressor and ensure proper vapor conditions, enhancing compressor protection without requiring complex control systems
Solution Approach 2:
The system uses temperature and pressure sensors to monitor refrigerant conditions at various points in the cycle. This feedback information is used by the expansion valve to dynamically adjust refrigerant flow rates, ensuring optimal superheat conditions and preventing compressor damage from liquid slugging or overheating
3Temperature
If outdoor condenser operates on hot day, then heat discharge is required, but temperature and pressure become excessively high causing efficiency loss or damage
Solution Approach 1:
The patent introduces a hydrothermal cooling loop that acts as an intermediary between the condenser and the environment. This loop uses a separate fluid circulation system with heat exchangers to transfer heat from the refrigerant, providing an additional heat rejection path that prevents excessive condenser temperature and pressure buildup, thereby maintaining system efficiency on hot days
4Temperature
If refrigerant temperature and pressure drop on cooler days, then heat discharge is reduced, but moisture condenses and freezes on evaporator
Solution Approach 1:
The patent employs continuous monitoring of evaporator temperature and refrigerant conditions through sensors that operate throughout the cooling cycle. The expansion valve continuously adjusts refrigerant flow to maintain optimal evaporator temperatures, ensuring continuous useful cooling action while preventing temperature drops that would cause moisture condensation and freezing on the evaporator surface
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 compressor loading, prevents overheating, and lowers the carbon footprint by improving the Seasonal Energy Efficiency Ratio (SEER) and minimizing the risk of refrigerant flooding, resulting in a more efficient and environmentally friendly refrigeration system.
Implementation Method 1
a serpentine pipe in a tank with antifreeze fluid cools the refrigerant before compression
Implementation Method 2
a coaxial pipe setup cools the compressed refrigerant
Implementation Method 3
a compressor with an inlet and an outlet for compressing said refrigerant
Implementation Method 4
an evaporator, a condenser, and communicating between them, an expansion device
Implementation Method 5
which is thereafter condensed to release its heat in a condenser cooled by a fan
Implementation Method 6
a fluid pump for pumping a fluid
Data Source
AI summary
A refrigeration apparatus that employs a refrigerant compressor has an expansion device coupled between an evaporator and a condenser. A first heat exchanger has (a) a main passage coupled between the evaporator and the inlet of the compressor, and (b) a complementary passage. This first heat exchanger may be a serpentine pipe inside a tank. A second heat exchanger has (a) a principal passage coupled between the condenser and the outlet of the compressor, and (b) an auxiliary passage. This second heat exchanger may be an inner and outer pair of coaxial pipes. The complementary passage of the first heat exchanger is coupled between a fluid pump and the auxiliary passage of the second heat exchanger. The auxiliary passage of the second heat exchanger is coupled between the fluid pump and the complementary passage of the first heat exchanger. A controller can operate the fluid pump based on measured parameters such as outside ambient temperature or compressor outlet pressure.