Refrigeration plant and operating method thereof
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Solution Overview
Problem
Multi-evaporator refrigeration plants face challenges in ensuring adequate lubrication to the compressor assembly, particularly during startup or defrosting events, leading to potential mechanical stress and inefficiencies due to the dispersion of lubricant oil in the refrigeration circuit.
Innovation Solution
A control device with sensing means and an optimization algorithm adjusts the compressor's operating regime to prevent overheating and ensure sufficient lubrication, eliminating the need for oil separators by monitoring temperature and flow conditions, and adjusting the compressor's operating parameters to maintain safe and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an oil separator is installed downstream of the compressor to separate and return lubricant, then the compressor is protected from lubricant loss, but the system complexity increases and manufacturing cost rises
Solution Approach 1:
The invention extracts and eliminates the oil separator component from the system by implementing a control strategy that prevents lubricant dispersion in the first place. The control device monitors system conditions and adjusts compressor operation to ensure adequate lubrication without requiring physical separation and return mechanisms, thereby simplifying the overall system structure while maintaining compressor protection.
Solution Approach 2:
The system uses the refrigerating fluid itself to carry and return lubricant to the compressor through intelligent control of compressor operating conditions. By regulating the compressor's operation based on detected system parameters, the refrigerating circuit naturally ensures lubricant circulation without additional mechanical components, making the system self-sufficient for lubrication management.
2Productivity
If the compressor operates at maximum speed during pull down phases, then rapid temperature lowering is achieved, but lubricant dispersion increases and compressor lubrication becomes insufficient
Solution Approach 1:
The invention implements dynamic control of the compressor operating regime based on real-time detection of system conditions. The control device continuously monitors parameters such as refrigerating fluid temperature and adjusts the compressor speed accordingly, transitioning between maximum speed for rapid cooling when lubrication is adequate and reduced speed when lubricant dispersion poses a risk, thereby dynamically balancing productivity and reliability.
Solution Approach 2:
The system incorporates feedback control where the control device detects system state parameters and uses this information to regulate compressor operation. By monitoring conditions that indicate lubricant dispersion risk and adjusting compressor speed in response, the system creates a closed-loop control mechanism that prevents lubrication insufficiency while maintaining optimal cooling performance.
Data Source
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AI summary
Described is a method of operating a refrigeration plant (10), wherein said refrigeration plant (10) comprises in sequence at least one evaporator assembly (11a, 11b, 11c), a compressor assembly (12), a condenser assembly (13), an expander assembly (14a, 14b, 14c), a control device (15) connected to compressor assembly (12) for operating it, sensing means (16a, 16b, 16c) designed to detect or derive an overheating temperature Tsh at an intake of the compressor assembly (12). This operation method comprises: - a standard operating mode A of the refrigeration plant (10) that sets an optimal value Ropt, for the operating regime of the compressor Rcomp(t) according to an optimization algorithm of the refrigeration plant (10); - a mode B, which verifies, by means of the control device (15), whether the overheating temperature Tsh exceeds a threshold value Max, to verify whether the operating regime Rcomp(t) of the compressor assembly (12) is greater than a safety value Mpd and, in the case of a positive outcome, to limit the operating regime Rcomp(t) of the compressor assembly (12) to a safety value Mpd, setting the optimal value Ropt, overriding mode A.