Refrigeration Circuit Control with Upstream Refrigerant Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Refrigeration circuits face inefficiencies and operational errors under variable cooling load conditions due to delayed feedback from sensors installed downstream of the evaporator, leading to premature refrigerant over-boiling or liquid refrigerant exit, which reduces efficiency and increases costs.
Innovation Solution
A refrigeration circuit control system that detects heat energy absorbed by refrigerant through sensors placed along the low side circuit, comparing detected values to ideal heat energy values to adjust refrigerant flow using a control throttle valve, with sensors installed within the evaporator coil and evaporator-to-compressor line to provide early detection and rapid response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sensors are installed downstream of the evaporator to detect refrigerant status, then the system can monitor refrigerant conditions, but the feedback is delayed causing operational errors under variable cooling loads
Solution Approach 1:
The patent applies preliminary action by installing sensors upstream of the evaporator to detect refrigerant conditions before they enter the evaporator. This allows the control system to take preventive measures by adjusting the throttle valve in advance, preventing liquid refrigerant from entering the evaporator and causing operational errors. The upstream positioning enables early detection and corrective action before the refrigerant reaches critical zones.
2Reliability
If large superheat settings are used to ensure complete vaporization under variable loads, then compressor protection is improved, but refrigeration circuit efficiency significantly decreases
Solution Approach 1:
The patent applies dynamics by implementing a dynamic control system that continuously adjusts the throttle valve based on real-time refrigerant conditions detected by upstream sensors. Instead of using fixed large superheat settings, the system dynamically modulates refrigerant flow to achieve optimal superheat values (typically 5-15°F) that provide adequate compressor protection while maximizing refrigeration efficiency. The control system adapts to varying cooling loads by adjusting valve position to maintain appropriate refrigerant vaporization.
Solution Approach 2:
The patent applies feedback by creating a closed-loop control system where upstream sensors continuously monitor refrigerant conditions (temperature, pressure, vapor quality) and send signals to the control system. The control system processes this feedback information and adjusts the throttle valve position accordingly to maintain optimal superheat levels. This feedback mechanism enables precise control that protects the compressor while minimizing energy loss by avoiding excessive superheat settings.
3Speed
If upstream sensors are installed within the evaporator coil and evaporator-to-compressor line, then early detection and rapid response is achieved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the refrigeration system into distinct monitoring zones and placing sensors at specific strategic locations (upstream of the evaporator, in the evaporator-to-compressor line). This segmented approach allows the system to monitor different refrigerant conditions at different points in the circuit, enabling precise localized control. The segmentation principle reduces overall system complexity by focusing sensors only where critical measurements are needed rather than throughout the entire system.
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 system enhances refrigeration circuit efficiency by allowing for timely adjustments in refrigerant flow, reducing the quantity of working fluid needed and minimizing system malfunctions, especially under transient cooling loads.
Implementation Method 1
As the refrigerant flows through the low side evaporator, evaporator outlet line and other low side lines to the compressor, the refrigerant absorbs heat energy from the ambient environment
Implementation Method 2
The condenser allows the refrigerant to reject heat energy to an ambient heat sink whereupon the refrigerant reverts to a liquid
Implementation Method 3
The compressor compresses the vapor refrigerant into a high-pressure, superheated vapor
Data Source
AI summary
A control system for a refrigeration circuit having one or more working fluid refrigerant sensors capable of measuring the fluid energy value of the refrigerant along a low side of the refrigeration circuit and regulating the flow of refrigerant to the circuit low side through reference to expected refrigerant fluid energy values.