Decentralized Refrigeration Layout for Low Refrigerant Overfeed
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Solution Overview
Problem
Industrial refrigeration systems require large amounts of liquid refrigerant due to the need for overfeeding to prevent pump cavitation, leading to inefficiencies and increased refrigerant usage.
Innovation Solution
A decentralized condenser evaporator system that transfers refrigerant mostly in a gaseous state, reducing the need for large centralized condenser systems and liquid refrigerant storage by using a centralized compressor arrangement and condenser evaporator systems with controlled pressure receivers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid refrigerant is transferred from centralized receiver to evaporators, then evaporators can be fed with liquid refrigerant for cooling, but large amounts of liquid refrigerant are required to prevent pump cavitation and ensure proper operation
Solution Approach 1:
The patent replaces the mechanical liquid pumping system with a gas-based delivery system. Instead of using liquid pumps to transfer refrigerant from a centralized receiver to evaporators, the system uses a centralized compressor to compress refrigerant gas and distribute it through gas lines to individual condenser evaporator systems. This eliminates the need for liquid pumps and the associated requirement for large liquid refrigerant inventories to prevent cavitation.
Solution Approach 2:
The patent changes the physical state parameter of the refrigerant from liquid to gas during transfer. By compressing refrigerant to a gaseous state and distributing it through gas lines, the system fundamentally alters the refrigerant's phase, thereby eliminating the cavitation issues inherent in liquid pumping systems and reducing the total refrigerant quantity needed.
2Ease of operation
If centralized condenser systems with liquid pumps are used, then liquid refrigerant can be delivered to evaporators, but the systems require large centralized engine rooms and condenser farms
Solution Approach 1:
The patent segments the centralized condenser system into multiple decentralized condenser evaporator systems (CES). Each CES is a self-contained unit with its own condenser, controlled pressure receiver, and evaporator, eliminating the need for large centralized condenser farms and engine rooms. The system is divided into modular units that can be distributed throughout the facility.
Solution Approach 2:
The patent extracts the condensing function from the centralized system and places it at each individual evaporator location. By taking out the condenser and receiver components and locating them at each CES, the system eliminates the need for large centralized condensing equipment and associated infrastructure.
3Reliability
If liquid overfeed system is used to prevent pump cavitation, then evaporators receive sufficient liquid refrigerant, but 85% or more of the liquid refrigerant returns un-evaporated requiring repumping
Solution Approach 1:
The patent replaces the liquid overfeed pumping system with a gas compression and distribution system. Instead of pumping liquid refrigerant in excess to ensure evaporator supply, the system compresses refrigerant gas and distributes it to individual CES units where it is condensed and evaporated as needed, eliminating the wasteful overfeed cycle.
Solution Approach 2:
Each condenser evaporator system in the patent is a self-contained unit that independently manages its own refrigerant needs. The CES includes its own controlled pressure receiver and evaporator, allowing it to self-regulate refrigerant distribution without requiring centralized pump control or excess liquid supply to multiple evaporators.
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 approach significantly reduces the overall refrigerant required, achieving a reduction of at least 85% while maintaining refrigeration capacity, and allows for more efficient operation and safety by minimizing ammonia usage.
Implementation Method 1
a compressor arrangement for compressing gaseous refrigerant from a first pressure to a second pressure wherein the second pressure is a condensing pressure
Implementation Method 2
a condenser for receiving gaseous refrigerant at a condensing pressure and condensing the refrigerant to a liquid refrigerant
Implementation Method 3
an evaporator for evaporating the liquid refrigerant to form gaseous refrigerant
Data Source
AI summary
A refrigeration system includes: a compressor arrangement for compressing gaseous refrigerant from a first pressure to a second pressure, wherein the second pressure comprises a condensing pressure; a plurality of condenser evaporator systems, wherein each condenser evaporator system comprises: (1) a condenser for receiving gaseous refrigerant at a condensing pressure and condensing the refrigerant to a liquid refrigerant; (2) a controlled pressure receiver for holding the liquid refrigerant from the condenser; and (3) an evaporator for evaporating liquid refrigerant from the controlled pressure receiver to form gaseous refrigerant; a first gaseous refrigerant feed line for feeding the gaseous refrigerant at the second pressure from the compressor arrangement to the plurality of condenser evaporator systems; and a second gaseous refrigerant feed line for feeding gaseous refrigerant from the plurality of condenser evaporator systems to the compressor arrangement.