Central chilled water plants are commonly used in commercial properties, university campuses, data centers, and industrial facilities. As the most critical component of HVAC and industrial cooling systems, they consume a significant amount of energy. Ensuring their safety, reliability, and efficiency is essential.

PSP-CHW is a universal plug-and-play (PNP) control system designed for central chilled water plants. It supports up to ten (10) chillers (with or without VFDs), ten (10) chilled water pumps (with or without VFDs), ten (10) cooling water pumps (with or without VFDs), ten (10) cooling towers (with or without VFDs), and four (4) free cooling heat exchangers.

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

• PSP is the primary controller, managing the entire central plant system from the main control station. It processes, stores, and presents data from the system’s subsystems (chillers, pumps, cooling towers, and heat exchangers). It also provides optimal control and coordination of these subsystems. The PSP communicates with a supervisory controller via an internal or stationary IP address.
• AIM controllers act as subsystem supervisory controllers:
  • AIM-CMP: for chillers
  • AIM-CT: for cooling towers
  • AIM-CHWP: for chilled water pumps
  • AIM-CWP: for cooling water pumps
  • AIM-ECO: for water-side economizers or free cooling heat exchangers
    These virtual controllers are embedded within the main control station.
• Digi controllers are individual equipment controllers located within or near each piece of equipment:
  • Digi-CMP: for chillers
  • Digi-CT: for cooling towers
  • Digi-CHWP: for chilled water pumps
  • Digi-CWP: for cooling water pumps
  • Digi-ECO: for free cooling heat exchangers

The main control station connects all Digi controllers through a multi-port gateway.

Customers can purchase PSP-CHW directly from Bes-Tech and hire local HVAC contractors for installation and setup. Bes-Tech engineers provide online support for installation and commissioning (CX) as needed.

Bes-tech can provide customers turn-key projects as well. Call for details.

PSP-CHW shall result in substantial electricity cost savings, enhance system reliability and safety, and extended lifespan for compressors, pump, fan, valve actuator, and et al.

• Precision chilled water supply and return temperature control: Control 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: Increased equipment lifespan by over 5 years due to more efficient operation and reduced motor cycling.
• Lower O&M Costs: Reduced operational and maintenance costs by 20% to 50%, primarily from fewer failures of compressors, pumps, and fans.
• Informative Preventive O&M: Automated FDD provides comprehensive equipment potential failure alarms to perform preventive O&M.
• Automated Equipment Failure Handling:  PSP-CHW automatically makes up the failure equipment duties to prevent negative impact on chilled water production and allow O&M staff perform repair in 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 current system operation and no interference with existing equipment.
• New Plant Integration: PSP-CHW can be purchased and used 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-CHW leverages AI technologies, solid engineering fundamentals, and industrial practices to optimize the performance of chilled water plant systems. Key principles and advantages include:

1. AI-Based Load Projection and Estimation: AI predicts future loads by analyzing historical data and real-time factors such as occupancy, weather, and usage patterns.
2. Optimal Chilled Water Supply and Return Temperature Setpoints: AI identifies ideal setpoints for chilled water supply and return temperatures, minimizing chiller and pump energy consumption or costs based on real-time load, demand response requirements, and real-time pricing.
3. Optimal Condensing Pressure and Cooling Water Setpoints: AI determines the optimal condensing pressure and cooling water supply/return temperature setpoints to minimize chiller energy consumption based on real-time load, ambient conditions (dry bulb and wet bulb), and condenser fan speed.
4. Chiller On/Off Control for Maximum Efficiency: AI optimizes chiller on/off sequences based on real-time demand, ensuring the chiller operates within its highest efficiency range.
5. Chilled Water Temperature Control for Maximum Comfort and Productivity: AI-assisted PI controls manage compressor speed (for VFD chillers/compressors), modulation slide valves (for screw compressors), or chilled water valves (for reciprocating compressors), ensuring precise chilled water supply temperature control.
6. Compressor On/Off Control for Optimal Pressure Balance: AI manages compressor on/off sequences to balance internal and external pressure, optimizing efficiency and performance.
7. Pump On/Off Control for Maximum Efficiency: AI uses a virtual pump flow meter to optimize pump on/off sequences based on real-time demand, ensuring the pump operates in its high-efficiency zone.
8. Pump Speed Control for Reduced Loop Resistance: AI leverages a virtual pump flow meter to adjust control valves to their most open positions, minimizing loop resistance and maximizing pump efficiency.
9. N+1 Principle and 80% Rule for System Safety, Reliability, and Efficiency: AI leverages N+1 principles and 80% rule to manage number of equipment in operation to prevent sudden system failure disaster.
10. Dual Safety Protection for Fans and Compressors: Motor doctor technology and virtual pressure sensors protect compressor motors from issues like overcurrent, phase dropouts, vibration, and pressure imbalances. They also protect indoor and condenser fan motors from overcurrent, phase issues, and vibration, eliminating conventional pressure sensor failure points and reducing maintenance costs.

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

The PSP-CHW® provides project payback in less than three years. In addition to energy savings, the PSP-CHW® reduces O&M costs significantly and improves system reliability and safety.

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

Facility Service Providers/Companies have an obligation to reduce energy consumption annually for their clients and installing PSP-CHW® will ensure satisfaction with this requirement. Moreover, installing the PSP-CHW® will significantly reduce O&M efforts and costs.

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

Central chilled water plants chillers are commonly used in commercial facilities, university campuses, industrial facilities, and data centers. This is a significant market for performance contracting and energy retrofits using the PSP-CHW®.

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

Offering PSP-CHW® to their clients can significantly increase revenue without head count increases. It will also increase the chances of renewing and/or adding new service contracts.

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

The PSP-CHW® is a PSP automation system. It can integrate with any BAS system through native Modbus and/or other protocols.

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

No!

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

Absolutely!

8. Does PSP-CHW® vary the chilled water flow through chillers?

The chilled water flow rate varies between 60% to 100% rated flow.

Bes-Tech, Inc. Corporate Office:

6916 N 97th Circle
Bldg B, Suite J, Mailbox 13
Omaha, Nebraska 68122-3037
O: 402-502-2340 I F: 402-502-2283
www.Bes-Tech.net