Refrigeration plant and method for preventing overheating by temperature-based control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-evaporator refrigeration plants face challenges in ensuring adequate lubrication of the compressor assembly, particularly during start-up or defrosting events, leading to potential overheating and mechanical stress due to insufficient lubricant supply.
Innovation Solution
A refrigeration plant and method that utilizes a control device to monitor overheating temperatures and adjust the compressor's operating regime dynamically, avoiding the need for lubricant separators by limiting the compressor's operation to safe parameters, ensuring adequate lubrication without additional hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the compressor operates at maximum speed during pull down phases, then cooling efficiency is improved, but lubricant supply to the compressor becomes insufficient
Solution Approach 1:
The patent implements dynamic control of the compressor operating regime based on real-time monitoring of lubricant temperature and system conditions. The control device adjusts compressor speed dynamically, preventing operation at maximum speed when lubricant temperature indicates insufficient lubrication, thereby resolving the contradiction between maintaining high cooling efficiency and ensuring adequate lubricant supply during pull down phases
Solution Approach 2:
The system employs feedback control by continuously monitoring lubricant temperature and using this information to adjust compressor operation. The control device receives temperature signals and modifies compressor speed accordingly, creating a closed-loop system that balances cooling performance with lubrication requirements, preventing the contradiction from manifesting
2Reliability
If an oil separator is installed downstream of the compressor, then lubricant return to the compressor is improved, but system complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and eliminates the oil separator component from the traditional refrigeration system by implementing alternative control methods. Through dynamic compressor regime control and temperature-based monitoring, the system achieves adequate lubricant return without requiring the additional hardware of an oil separator, thereby reducing system complexity while maintaining reliability
Solution Approach 2:
The system enables self-service lubrication management by using the refrigeration cycle itself and control algorithms to ensure proper lubricant circulation. The dynamic adjustment of compressor operation and monitoring of lubricant temperature allows the system to self-regulate lubricant return without external辅助设备 like oil separators, simplifying the overall system
3Speed
If the lubricant is dispersed in the refrigerating circuit at high temperatures, then the lubricant drawing capacity of the cooling fluid decreases, but the compressor still operates at high speed
Solution Approach 1:
The control device dynamically adjusts compressor speed based on real-time lubricant temperature conditions. When lubricant temperature rises and disperses lubricant in the refrigerating circuit, reducing drawing capacity, the system automatically reduces compressor speed to match the diminished lubrication capability, preventing the contradiction between maintaining high speed operation and ensuring adequate lubrication
Data Source
AI summary
A method of operating a refrigeration plant which comprises sensing means designed to detect or derive an overheating temperature Tsh at an intake of a compressor assembly of the refrigeration plant. The method comprises: a standard operating mode A that sets an optimal value Ropt, for the operating regime of the compressor Rcomp(t); a mode B, which verifies, whether the overheating temperature Tsh exceeds a threshold value Max, to verify whether the operating regime Rcomp(t) of the compressor assembly 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 to a safety value Mpd, setting the optimal value Ropt, overriding mode A.