Flow Control Valve Layout for Stable Refrigerant Header Supply
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Solution Overview
Problem
Refrigeration systems for commercial display cases often face issues with reduced refrigerant availability in the liquid header, leading to low suction pressures and compressor shutoff due to inadequate cooling, especially after startup or power outages.
Innovation Solution
A refrigeration system design featuring a plurality of refrigerated display cases with dedicated evaporators, a compressor assembly, a remotely located air-cooled condenser, and a gas main and liquid main in fluid communication, with a valve to regulate refrigerant flow, allowing for efficient refrigerant distribution and condensation, thereby maintaining consistent cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a centralized refrigeration system with remote condenser is used, then cooling capacity is improved, but refrigerant availability in liquid header is reduced
Solution Approach 1:
The receiver is positioned at a lower elevation than the condenser to enable gravity-driven refrigerant drainage. This preliminary positioning ensures that liquid refrigerant naturally flows to the receiver after condensation, maintaining adequate refrigerant availability in the liquid header before it is needed for evaporator operation.
Solution Approach 2:
The receiver acts as an intermediary component between the condenser and the liquid header. It temporarily stores and regulates refrigerant flow, ensuring consistent refrigerant supply to the evaporators while preventing liquid refrigerant deficiency in the liquid header that would otherwise occur in centralized systems.
2Productivity
If refrigerant flow is increased to maintain cooling, then cooling performance is improved, but compressor shutoff due to low suction pressure occurs
Solution Approach 1:
The system uses suction pressure sensors that provide feedback to the controller. When suction pressure drops below a threshold, the controller modulates the expansion valves to reduce refrigerant flow, preventing compressor shutoff. This closed-loop feedback ensures both cooling performance and compressor reliability are maintained.
Solution Approach 2:
The expansion valves are designed with dynamic modulation capability, allowing real-time adjustment of refrigerant flow based on system conditions. This dynamic control enables the system to maintain optimal cooling performance while preventing conditions that would cause compressor shutoff.
3Productivity
If evaporators are positioned within display cases, then cooling efficiency is improved, but refrigerant distribution control becomes difficult
Solution Approach 1:
The system divides refrigerant distribution control into multiple independent zones, with each evaporator equipped with its own expansion valve. This segmentation allows individual control of refrigerant flow to each evaporator, maintaining high cooling efficiency while simplifying distribution control through modular, independent regulation points.
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 design ensures consistent refrigerant flow and pressure, preventing compressor shutoff and ensuring reliable cooling of display cases by regulating refrigerant distribution and condensation, even under varying conditions.
Implementation Method 1
Each of the plurality of refrigerated display cases includes a dedicated evaporator that cools return air from the respective refrigerated display case by at least partially evaporating a refrigerant
Implementation Method 2
A compressor assembly is in fluid communication with the plurality of evaporators and compresses the evaporated refrigerant
Implementation Method 3
A gas main is in fluid communication with an inlet of the condenser and directs refrigerant from the compressor assembly to the condenser
Data Source
AI summary
A control valve to regulate flow of refrigerant through a refrigeration system that includes a plurality of refrigerated display cases. Each of the plurality of display cases includes a dedicated evaporator that cools return air by at least partially evaporating a refrigerant. A compressor assembly compresses evaporated refrigerant received from the plurality of evaporators. The system further includes a condenser located remotely from the plurality of display cases that rejects heat from the refrigerant to an environment. A gas main is in fluid communication with an inlet of the condenser and directs refrigerant from the compressor assembly to the condenser. A liquid main is in fluid communication with an outlet of the condenser and directs refrigerant from the condenser to the plurality of evaporators. The valve is fluidly coupled between the gas main and the liquid main, and regulates flow of refrigerant from the gas main to the liquid main.