Ammonia refrigeration plants are essential for cold storage and various industrial processes, serving as major energy consumers. Ensuring their safety, reliability, and efficiency is crucial.

The PSP-CIR is a universal plug-set-play (PSP) control system for these plants, capable of managing up to ten (10) compressors (with or without VFDs), three refrigeration levels (Low Temperature, Medium Temperature, and High Temperature), ten (10) evaporative cooling towers (with or without VFDs),  ten (10) refrigeration spaces, and up to ten (10) evaporators for each refrigeration space. It also accommodates all types of defrosting methods (hot gas, electric, on/off, liquid, and manual defrosting).

The PSP-CIR system includes three levels of controllers: PSP, AIM, and Digi.

• The PSP serves as the primary controller, overseeing the entire refrigeration plant system from the main control station. It processes, stores, and presents data from subsystems, including compressors, cooling towers, evaporators, and economizers, while ensuring optimal control and coordination among them. The PSP communicates with a supervisory controller through an internal or static IP address.
• The AIM controllers act as subsystem supervisory controllers:
  • AIM-CMP: for compressors
  • AIM-CT: for evaporative cooling towers
  • AIM-EVP: for space evaporators

These virtual controllers are embedded within the main control station.

• The Digi controllers are individual equipment controllers located within or near each piece of equipment:
  • Digi-CMP: for compressor
  • Digi-CT: for cooling tower
  • Digi-EVP: for evaporator
• The Digi-ECO controls hot liquid defrosting

Customers can purchase the PSP-CIR directly from Bes-Tech and engage local HVAC contractors for installation and setup. Bes-Tech engineers offer online support for installation and commissioning (CX) when needed.

The main control station connects to all Digi controllers through a multi-port gateway. It can also connect to existing controllers through the same gateway. In such case, a special setup is required.

Additionally, Bes-Tech  provides full turn-key project solutions. Call for more details.

Installation of PSP-CIR leads to substantial electricity cost savings, enhanced system reliability and safety, and extend lifespan for compressors, pumps, fans, and valve actuators.

• Precise space temperature control: Controls temperature within ±1°F of the setpoint.
• Energy and/or Cost Savings: Reduction in electricity consumption or cost by 25% to 45%.
• Extended Equipment Lifespan: Extends equipment lifespan by over 5 years through more efficient operation and reduced motor cycling.
• Lower O&M Costs: Reduces operational and maintenance costs by 20% to 50%, mainly by minimizing failures of compressors, pumps, and fans.
• Preventive O&M: Automated FDD provides comprehensive potential equipment failure alarms to perform preventive O&M.
• Automated Equipment Failure Handling: PSP-CIR automatically makes up the failed equipment duties to prevent negative impact on refrigeration production and allow O&M staff perform repair in a calm and scheduled manner.
• Utility Incentives: Many utilities provide incentives to this technology and controllers. Consult your local utility energy program for details.

• PSP: Plug, Set, and Play: Easy installation with minimal setup required.
• Retrofit Existing Equipment: Can be installed with no impact on the current system’s operation and no interference with existing equipment.
• New Plant Integration: PSP-CIR can serve as the Building Automation System (BAS) for new installations.
• Standalone or Integrated Operation: Includes a local workstation for system setup and graphical interface, with standard data communication ports for integration with any supervisory system or controller.

PSP-CIR leverages AI technologies, engineering fundamentals, and industrial practices to optimize the performance of ammonia refrigeration plant systems. Key principles and advantages include:

1. AI-Based Load Projection and Estimation: AI-driven technologies predict future loads by analyzing historical data along with real-time factors such as weather conditions and usage patterns.
2. Optimal Space Temperature Setpoints or Reset: AI determines the optimal setpoints for each space based on temperature range specifications, real-time load and load pattern, demand response requirements, and real-time pricing.
3. Optimal Suction Pressure Setpoints: AI determines the optimal setpoints for suction pressure for each level of refrigeration and minimize compressor energy consumption or costs based on space temperature setpoint, real-time load, demand response requirements, and real-time pricing.
4. Optimal Condensing Pressure Setpoints: AI determines the optimal condensing pressure setpoint based on real-time load, ambient conditions (dry bulb and wet bulb temperatures), minimum compressor lift, and condenser fan speed.
5. On/Off Control: AI algorithms leverage bee swarm principles, N+1 principles, and 80% rules to determine the optimal number of evaporators, evaporative cooling towers, and compressors in operation; and balance compressor internal and external compression ratio, minimize fan power, improve system reliability, and enhance the safety.
6. Compressor Speed Control: Modulates compressor speed to balance internal and external compression ratio.
7. Smart defrosting control: AI algorithms detect the frost build-up and melting, as well as the start and stop times for defrosting, by analyzing patterns in heat transfer coefficient, fan power, and evaporator surface temperature.
8. Hot Liquid Defrosting: AI algorithms minimize the hot gas use for defrosting based on the availability of hot liquid.
9. Dual Safety Protection for Fans and Compressors: Motor doctor technology and virtual pressure sensors safeguard against compressor motor failure or damage due to overcurrent, phase dropouts, vibration, and pressure imbalances. They also protect indoor and condenser fan motors from damage due to similar issues. This technology eliminates conventional pressure sensor failure points and reduces maintenance costs.

1. What are some important benefits to Building Owners that install PSP-CIR®?

2. Why do Facility Service Providers/Companies recommend the PSP-CIR® to their clients?

3. What important facts should ESCOs and Energy Consultants know about the PSP-CIR®?

4. Why should MEP and BAS Contractors install PSP-CIR®?

5. How is the PSP-CIR® integrated with BAS systems?

6. Does installing the PSP-CIR® void manufacturer warranties?

7. Can PSP-CIR® reuse the existing sensors and actuators?