Refrigeration Compressor Management System: An Optimized SCADA Solution for Energy Efficiency, Machine Protection, and Safety

Introduction

Modern cold storage and sophisticated cold chain warehouses have revolutionized the food storage and seasoning industries, especially in seafood and other sectors. These advancements are largely due to the thermodynamic cycles and chemical properties of refrigerants like Ammonia and Freon. Despite these benefits, the industry faces high costs due to installation, maintenance, and effective monitoring of multiple compressor systems, which are the heart of refrigeration operations.

Do critical temperature control issues and unpredictable machine trips affect your business? Does high energy consumption and inefficient resource utilization hinder your long-term business goals?

FAIZAL offers an optimum solution to maximize asset efficiency and reliability. Our SCADA-based solution is a highly efficient process monitoring and compressor management system for cold storage facilities.

Problem Statement

The challenges in traditional compressor management include:

1. Inefficient Temperature Control: Traditional ON-OFF control of compressors results in poor temperature maintenance, affecting product quality and compressor lifespan due to frequent start-ups and high energy consumption.
2. Unpredictable Machine Trips: These disrupt operations, leading to compromised product quality and preservation standards, ultimately affecting profitability and credibility.
3. Inefficient Defrosting: Manual defrosting is often ineffective, reducing the cooling capacity of the refrigeration system as ice on evaporator coils hampers heat transfer.
4. Auxiliary Equipment Integration: Improper start-up and integration of auxiliary pumps and fans significantly impact compressor safety and overall refrigeration cycle efficiency.
5. Multiple Compressor Management: Effective load distribution and management are crucial for cost-effective refrigeration, which traditional systems fail to achieve.
6. Inadequate Monitoring: Traditional systems only indicate motor on/off status, insufficient for comprehensive cold storage operation.
7. Drastic Temperature Fluctuations: During door opening and transportation, temperature changes drastically, which traditional systems cannot handle efficiently.
8. Suction Temperature Impact: Suction temperature affects compressor efficiency, with a 2-3% power drop for each degree Fahrenheit rise, unaccounted for by traditional systems.
9. Refrigerant Leakage: Leakage poses significant safety risks, particularly with toxic refrigerants like Ammonia, necessitating robust process interlock and safety protocols.
10. Thermal Expansion Valve Tuning: Control systems require tuning for parameter control, including thermal expansion valve adjustments for optimal performance.

The Solution

FAIZAL’s advanced industrial PLC-SCADA solution addresses these challenges by monitoring and analyzing machine performance and requirements. Our solution includes:

1. Suction Pressure-Based PID Control: Instead of traditional temperature sensing and ON/OFF control, our system uses suction pressure as an indicator of temperature demand. The PID output controls machine speed via a variable frequency drive (VFD), adapting to rapid fluctuations caused by door openings and material handling. This approach reduces electricity consumption and extends compressor life by minimizing start-stop cycles.
2. Predictive Maintenance: Our system monitors parameters like oil pressure, motor winding temperature, oil separator status, and overall machine vibration, enabling live monitoring and predictive maintenance scheduling through the SCADA system.
3. Safety and Efficiency: The PLC system provides interlocks and monitors auxiliary systems such as evaporator fans, oil pumps, water chiller pumps, and refrigerant pumps, enhancing safety and performance.
4. Advanced Defrosting: Sensor-based defrosting ensures effective heat transfer, overcoming the limitations of fixed-time manual defrosting.
5. Comprehensive Monitoring and Reporting: The SCADA system offers graphical representation, monitoring of critical parameters, and detailed reports on compressor running hours, load status, and energy consumption, including SMS alerts during critical alarms.

System Architecture

FAIZAL’s white paper on the Compressor Management System for Cold Chain Facilities outlines our SCADA solution’s architecture:

• Multiple Compressor Management: The system manages multiple compressors, adjusting individual compressor speed based on load demand and combining different rated compressors for energy efficiency.
• Refrigerant Leak Detection: Integration of leak detection sensors adds an extra layer of safety.
• Data Visualization and Analysis: The SCADA system provides real-time and historical data visualization, graphical representations of daily, weekly, and monthly electricity consumption, and the ability to calculate electricity bills.

Key Features

• Energy Efficiency: Speed control of compressors according to temperature demand improves energy efficiency and machine life.
• Optimized Machine Utilization: Multiple compressor management allows for optimum machine utilization through load sharing and speed control.
• Predictive Maintenance: Machine monitoring parameters help avoid unexpected trips and facilitate planned maintenance.
• Enhanced Safety and Performance: Auxiliary pump and fan interlocks increase safety and operational efficiency.
• Effective Defrosting: Sensor-based defrosting ensures maximum heat transfer.
• Critical Alarms: SMS alerts for critical alarm points ensure timely intervention.
• Fine-Tuning Capabilities: System fine-tuning achieves optimal operating conditions.

By implementing FAIZAL’s advanced SCADA solution, cold storage facilities can achieve energy-efficient, safe, and reliable compressor management, ultimately enhancing product quality and operational efficiency.