Refrigeration Heat Exchanger Loop for Compressor Pressure Control
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Solution Overview
Problem
Conventional direct expansion refrigeration systems face inefficiencies and damage risks due to temperature and pressure fluctuations, leading to increased energy consumption and carbon footprint, with existing air conditioners having limited improvements in efficiency over the past decade.
Innovation Solution
A refrigeration apparatus with an internal hydrothermal cooling loop, featuring a compressor, evaporator, condenser, and heat exchangers, including a fluid pump and sensors to regulate fluid flow and temperature, moderating temperatures and pressures to prevent overheating and damage, and a remediation system to divert refrigerant and adjust compressor load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional direct expansion refrigeration systems are used, then the system structure is simple, but the energy efficiency is low and carbon footprint is high
Solution Approach 1:
The system is divided into multiple independent heat exchangers (first heat exchanger with main and complementary passages, second heat exchanger with principal and auxiliary passages) that can operate semi-independently. This segmentation allows optimized heat transfer paths while maintaining manageable system complexity through modular design.
Solution Approach 2:
The complementary passage of the first heat exchanger and the auxiliary passage of the second heat exchanger are nested to form an internal hydrothermal cooling loop. This nested configuration allows the cooling fluid to circulate through both heat exchangers efficiently, improving energy recovery while maintaining a compact structure.
2Reliability
If the condenser operates on hot days, then the system can cool the home, but the condenser temperature and pressure become excessively high causing efficiency loss and potential damage
Solution Approach 1:
The first heat exchanger cools the refrigerant in the main passage before it enters the compressor by using the cooling fluid circulating in the complementary passage. This preliminary cooling action prevents excessive temperature and pressure buildup in the compressor, enhancing reliability before the high-temperature condition occurs.
Solution Approach 2:
A cooling fluid (water or air) acts as an intermediary medium between the refrigerant and the external environment. The cooling fluid absorbs heat from the refrigerant in the heat exchangers and carries it away, preventing direct thermal buildup in the compressor and condenser.
3Adaptability or versatility
If the refrigerant temperature drops on cooler days, then the system adapts to lower ambient conditions, but moisture condenses and freezes on the evaporator causing operational issues
Solution Approach 1:
Sensors monitor the temperature and pressure conditions in the system and provide feedback to the controller. The controller adjusts the operation of the fluid pump and heat exchangers based on this feedback, preventing evaporator freezing by maintaining appropriate temperature thresholds even when ambient conditions are cool.
Solution Approach 2:
The system changes operating parameters (fluid flow rate, heat exchanger activation) based on ambient temperature conditions. On cooler days, the controller modifies the cooling loop operation to prevent excessive temperature drops that would cause evaporator freezing, while still maintaining adaptability to the lower ambient conditions.
4Productivity
If the expansion valve allows high evaporation rate, then cooling capacity is increased, but the compressor experiences high load and overheating
Solution Approach 1:
The first heat exchanger provides preliminary cooling to the refrigerant before it enters the compressor, reducing the compressor's thermal load. This allows the system to maintain high evaporation rates for cooling capacity while preventing compressor overheating and energy loss.
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 significantly improves the Seasonal Energy Efficiency Ratio (SEER) and reduces the carbon footprint by moderating compressor temperatures and pressures, preventing damage, and optimizing energy use.
Implementation Method 1
The apparatus also has a first and a second heat exchanger. The first heat exchanger has (a) a main passage communicating between the evaporator and the inlet of the compressor, and (b) a complementary passage. The second heat exchanger has (a) a principal passage communicating between the condenser and the outlet of the compressor, and (b) an auxiliary passage.
Implementation Method 2
Also included is a fluid pump for pumping a fluid. The complementary passage of the first heat exchanger communicates between the fluid pump and the auxiliary passage of the second heat exchanger.
Implementation Method 3
The compressor compresses and thereby heats a gaseous refrigerant, which is thereafter condensed to release its heat in a condenser cooled by a fan.
Implementation Method 4
The liquefied refrigerant then passes through an expansion valve and an evaporator, which evaporate the refrigerant before it is returned to the compressor.
Implementation Method 5
The compressor compresses and thereby heats a gaseous refrigerant, which is thereafter condensed to release its heat in a condenser cooled by a fan.
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.