System Configurations

percent of the system load. At system loads greater than 50 percent, the upstream chiller is preferentially loaded because it will attempt to produce the design leaving chilled-water temperature. Any portion of the load that remains is directed to the downstream chiller.

If chiller setpoints are staggered (upstream at 49°F [9.4°C] and downstream at 42°F [5.5°C]), the downstream chiller is loaded first. The upstream machine then meets any portion of the system load that the downstream chiller cannot meet. This control strategy offers several benefits. The first is that the upstream chiller is always operating at an elevated temperature. This allows it to operate at a higher efficiency. Also, placing an absorption chiller in the upstream position increases its capacity. As an example, an absorption chiller that can produce 500 tons [1,760 kW] at a leaving chilled-water temperature of 44°F [6.6°C] may produce 600 tons [2,110 kW] at 50°F [10°C]. Centrifugal, helical-rotary, reciprocating, and scroll chillers experience capacity and efficiency changes to a lesser degree. By judicious use of the series configuration, these benefits can provide reduced installed cost and fuel flexibility to the building owner. While not shown, a single manual bypass with proper valving can provide for servicing of chillers.

Equal loading of the two chillers may be accomplished by using a chiller plant management system to dynamically reset the upstream chiller’s setpoint in response to changes in system load.

Primary–Secondary (Decoupled) Systems

The root cause of the difficulties with parallel chiller control in a constant volume system is the fixed relationship between chiller- and system-flow rates. If, instead, we can hydraulically decouple the production (chiller) piping from the distribution (load) piping, it is possible to control them separately. The fixed relationships are then broken apart. The production pumps are typically constant volume, while the distribution pumps are variable volume.

Hydraulic decoupling

Figure 28 shows the basic decoupled system. This strategy is also referred to as a primary–secondary pumping arrangement. Separate pumps are dedicated to production and distribution. While the same water is pumped twice (by different pumps), there is no duplication of pumping energy. This is because the production pumps overcome only the chiller and production- side pressure drop while the distribution pumps overcome only the distribution system pressure drop.

SYS-APM001-EN

Chiller System Design and Control

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Trane SYS-APM001-EN manual Primary-Secondary Decoupled Systems, Hydraulic decoupling
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SYS-APM001-EN specifications

The Trane SYS-APM001-EN is an advanced control system designed for HVAC (Heating, Ventilation, and Air Conditioning) applications, specifically tailored to enhance energy efficiency and system performance. This comprehensive solution integrates cutting-edge technologies to optimize climate control in commercial and industrial environments.

One of the main features of the SYS-APM001-EN is its intuitive user interface. The system is equipped with a large, easy-to-read display that provides real-time data on system performance, energy usage, and environmental conditions. This user-friendly interface makes it simple for operators to monitor and adjust settings, ensuring optimal comfort levels and efficient energy consumption.

Another key characteristic of the SYS-APM001-EN is its advanced data analytics capabilities. The system collects and analyzes data from various sensors throughout the building, providing insights into occupancy patterns, equipment performance, and energy consumption trends. This data-driven approach allows facility managers to make informed decisions about system adjustments, predictive maintenance, and energy savings.

The SYS-APM001-EN also boasts robust integration capabilities. It can seamlessly connect with a variety of building management systems (BMS) and other third-party devices. This interoperability enables a cohesive operational ecosystem where HVAC systems can communicate and cooperate with lighting, security, and fire safety systems, enhancing overall building efficiency.

Energy efficiency is a hallmark of the SYS-APM001-EN, as it implements sophisticated algorithms to optimize system operation. These algorithms adjust equipment performance in real-time based on current conditions, thereby reducing energy waste and lowering operational costs. The system is designed to support multiple energy-saving strategies, including demand-controlled ventilation and optimal start/stop scheduling.

Additionally, the SYS-APM001-EN is built with scalability in mind, accommodating facilities of various sizes and configurations. Whether it’s a small office building or a large industrial complex, the system can be tailored to meet specific needs, ensuring that HVAC performance aligns with operational goals.

In conclusion, the Trane SYS-APM001-EN is an innovative HVAC control solution that emphasizes user experience, data-driven decision-making, and energy efficiency. With its advanced features and technologies, it is an essential tool for optimizing building performance and enhancing occupant comfort while reducing environmental impact.
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