Cooling system for efficient operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing direct expansion cooling systems operate with substantial superheat, which negatively affects efficiency and increases installation costs, as they require more heat than necessary for evaporation, leading to inefficiencies and higher operational costs.
Innovation Solution
A superheat vapor quality sensor is placed between the evaporator and compressor to monitor the superheat vapor quality, allowing for optimized operation by controlling the evaporator inlet valve based on sensor signals, reducing superheat while maintaining high evaporation levels, and extending the operating range into the two-phase region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If substantial superheat is used to ensure complete evaporation of refrigerant, then reliability of operation is improved, but energy efficiency deteriorates and installation costs increase
Solution Approach 1:
The patent applies feedback control by using a sensor to detect the presence of liquid refrigerant in the suction conduit and automatically adjusting the expansion valve opening based on this detection. This closed-loop control system maintains complete evaporation (reliability) while minimizing superheat (energy efficiency) by dynamically adapting to actual refrigerant conditions rather than using fixed substantial superheat margins.
Solution Approach 2:
The system changes the operating parameters by transitioning from fixed substantial superheat to dynamic superheat control based on detected liquid refrigerant presence. The expansion valve opening is continuously adjusted to maintain optimal evaporation, reducing unnecessary superheat and improving energy efficiency while ensuring complete vaporization.
2Reliability
If substantial superheat is used to ensure complete evaporation of refrigerant, then reliability of operation is improved, but installation costs worsen
Solution Approach 1:
The feedback control system replaces the need for oversized components required by traditional substantial superheat methods. By using sensor detection and automatic expansion valve control, the system achieves complete evaporation with properly sized equipment, reducing installation costs while maintaining reliability.
3Reliability
If expansion valve is controlled to prevent liquid refrigerant, then reliability is improved, but device complexity worsens
Solution Approach 1:
The patent implements a relatively simple feedback control system consisting of a sensor in the suction conduit, a controller, and an expansion valve actuator. This straightforward closed-loop configuration detects liquid refrigerant presence and automatically adjusts the expansion valve, achieving reliable liquid prevention without excessive system complexity.
Solution Approach 2:
The system employs self-service control where the detected liquid refrigerant presence directly triggers automatic expansion valve adjustment. The system monitors and corrects its own operation without external intervention, maintaining reliability while keeping control logic simple and intuitive.
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 solution enables efficient operation by reducing superheat, improving the cooling system's efficiency, and reducing operational costs while ensuring complete evaporation, even under varying load conditions.
Implementation Method 1
The sensor body (46) is in thermal contact with a wall of the conduit (34). The heating element (48) is arranged to supply heat
Implementation Method 2
a temperature sensing element arranged in thermal contact with the sensor body. The superheat vapor quality sensor is arranged in thermal contact with a wall of the conduit (34)
Implementation Method 3
The evaporator is disposed to evaporate the liquid ammonia
Implementation Method 4
heat from the sensor is removed through refrigerant evaporation
Implementation Method 5
The compressor is disposed to compress ammonia vapor
Implementation Method 6
The condenser is disposed to condense the ammonia vapor to obtain liquid ammonia
Data Source
AI summary
The invention relates to a cooling system and operating method therefor with a direct expansion cooling circuit for an ammonia refrigerant. A compressor 12 is provided to compress ammonia vapor 11. A condenser is provided to condense the ammonia vapor to obtain liquid ammonia 20. An evaporator 32 is provided to evaporate the liquid ammonia. A superheat vapor quality sensor 40 is arranged at a conduit 34 between at least a portion of the evaporator 32 and the compressor 12. The superheat vapor quality sensor 40 comprises a heating element 48 and a temperature sensing element 52. The superheat vapor quality sensor 40 is disposed to deliver a sensor signal S indicative of a superheat vapor quality X of refrigerant flowing through the conduit 34 from an output of the temperature sensing element 52. The superheat vapor quality sensor 40 is arranged on a wall of a horizontally arranged portion of the conduit 34 in a position forming an angle of more than 120° to a vertical upward direction.