Trane SYS-APM001-EN manual Common, Campus, Tertiary or distributed

Page 55

System Configurations

Elevated return-water temperatures. Because unused chilled water does not bypass the cooling coils (two-way, rather than three-way, control valves), all water that is returned accomplishes some cooling. Theoretically, the return- water temperature will always be at least as high as it is at full load. From a practical standpoint, this is not always possible, but it is closely approached in a properly operating system. In fact, at most part-load conditions, water returns from properly functioning air-conditioning coils at higher-than-design temperatures. In systems that use counterflow cooling coils, this occurs because the water leaving the coil tries to approach the temperature of the entering airstream.

Warm return water provides advantages in system design. It permits “preferential” loading of chillers, for example. Warmer return water is useful with all systems, but particularly so with heat recovery and free cooling applications. For more information, refer to “Chilled-Water System Variations” on page 70.

Pumping arrangements

Common

Various distribution system arrangements are possible. A single, large pumping station, as shown in Figure 29, can be used. The station may consist of single or multiplexed pumps sequenced on or off.

Figure 32. Campus pumping arrangement

Campus

Alternatively, each of several secondary distribution systems can be piped in parallel. For example, Figure 32 shows separate distribution systems for each of three loads. Clearly, this arrangement lends itself to the possibility of plant expansion by simply adding secondary distribution pumps to the existing plant.

Tertiary or distributed

Secondary Distribution Pumps

Tertiary pumping is an extension of primary–secondary pumping when the distribution or secondary pump must overcome diverse and severe pumping requirements.

System loads can also be decoupled from the secondary distribution system. This is frequently done with very large systems. Figure 33 shows one method of providing “tertiary pumping” at the loads. A “load” may be something as large as an entire building, or as small as an individual cooling coil. When one or more loads have extreme head requirements, the degree of range ability of the distribution pump is severely curtailed. Tertiary pumping allows the excess pumping requirements to be placed on a third pumping system thus shielding the distribution pump from divergent pressure requirements.

Most importantly, the loads must be controlled so that only the water needed to perform cooling is taken from the distribution loop. Water must not be allowed to flow into the return piping until it has sustained a specific temperature rise. Tertiary pumps can be either constant flow or variable flow, to best meet the terminal load requirements.

SYS-APM001-EN

Chiller System Design and Control

49

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Contents May Page Chiller System Design and Control Preface Contents 100 Chiller Primary System ComponentsChiller evaporator Primary System ComponentsEffect of chilled-water flow rate and variation Effect of chilled-water temperatureWater-cooled condenser Effect of condenser-water temperatureEffect of condenser-water flow rate Packaged or Split System? MaintenanceAir-cooled condenser Air-cooled versus water-cooled condensersEnergy efficiency Low-ambient operationAir-cooled or water-cooled efficiency LoadsTwo-way valve load control Three-way valve load controlFace-and-bypass dampers Variable-speed pump load controlChilled-water pump Chilled-Water Distribution SystemPump per chiller Distribution pipingManifolded pumps Constant flow system Pumping arrangementsVariable-primary system Condenser-Water SystemCooling tower Primary-secondary systemSingle tower per chiller Condenser-water pumping arrangementsEffect of load on cooling tower performance Effect of ambient conditions on cooling tower performanceChiller control Unit-Level ControlsRecommended chiller-monitoring points per Ashrae Standard Centrifugal chiller with AFD Centrifugal chiller capacity controlAFD on both chillers Small Chilled-Water Systems 1-2 chillers Application ConsiderationsVariable flow Application Considerations Constant flowCondensing method Part load system operation Application ConsiderationsNumber of chillers Parallel or seriesManaging control complexity Mid-Sized Chilled-Water Systems ChillersPreferential vs. equalized loading and run-time Large Chilled-Water Systems + Chillers, District Cooling Large chilled-water system schematicPipe size PowerWater Controls Chiller performance testingLimitations of field performance testing Chiller Plant System PerformanceSYS-APM001-EN SYS-APM001-EN Guidance for Chilled- and Condenser-Water Flow Rates System Design OptionsStandard rating temperatures Chilled-Water TemperaturesSystem Design Options Chilled- and Condenser-Water Flow Rates Condenser-Water TemperaturesStandard rating flow conditions System Design Options Selecting flow rates Low-flow conditions for cooling tower Base Case Low Flow DP2/DP1 = Flow2/Flow11.85System summary at full load Total system power Component Power kW Base Case Low FlowChilled water system performance at part load Coil response to decreased entering water temperatureSystem design Entering fluid temperature, F CCooling-tower options with low flow Smaller towerSame tower, smaller approach ΔT2 = 99.1 78 = 21.1F or 37.3 25.6 = 11.7CSame tower, smaller approach Present Smaller Approach Same tower, larger chillerRetrofit capacity changes Larger Present Chiller Same tower Retrofit opportunitiesCost Implications Misconception 1-Low flow is only good for long piping runs Misconceptions about Low-Flow RatesKWh SYS-APM001-EN Parallel Chillers System ConfigurationsParallel chillers with separate, dedicated chiller pumps System ConfigurationsSeries chillers Series ChillersHydraulic decoupling Primary-Secondary Decoupled SystemsCheck valves Production loop System Configurations ProductionDistribution-loop benefits of decoupled system arrangement System Configurations DistributionCampus CommonTertiary or distributed Tertiary pumping arrangement Decoupled system-principle of operationFlow-based control Temperature-sensingFlow-sensing Adding a chiller Multiple chilled-water plants on a distribution loopSubtracting a chiller Double-ended decoupled system Pump control in a double-ended decoupled systemChiller sequencing in a double-ended decoupled system Other plant designs Variable-Primary-Flow SystemsOperational savings of VPF designs Advantages of variable primary flowDispelling a common misconception Chiller selection requirementsFlow, ft.water Flow rate Flow-rate changes that result from isolation-valve operation Managing transient water flowsSystem Configurations Effect of dissimilar evaporator pressure drops System design and control requirementsAccurate flow measurement Bypass flow control Chiller sequencing in VPF systemsFlow-rate-fluctuation examples Adding a chiller in a VPF systemSequencing based on load Subtracting a chiller in a VPF systemSelect slow-acting valves to control the airside coils Other VPF control considerationsConsider a series arrangement for small VPF applications Plant configurationChiller selection Guidelines for a successful VPF systemAirside control Plant configurationBypass flow Chiller sequencingPlate-and-frame heat exchanger Heat RecoveryChilled-Water System Variations Condenser Free Cooling or Water EconomizerRefrigerant migration Chilled-Water System VariationsWell, river, or lake water Refrigerant migration chiller in free-cooling modePreferential loading parallel arrangement Preferential LoadingSidestream plate-and-frame heat exchanger Preferential loading sidestream arrangementChilled-Water System Variations Sidestream with alternative fuels or absorptionSidestream system control Preferential loading series arrangementSeries-series counterflow Series-Counterflow ApplicationEvaporators Unequal Chiller SizingCondensers Low ΔT Syndrome System Issues and ChallengesAmount of Fluid in the Loop Example System Issues and ChallengesChiller response to changing conditions System response to changing conditionsMinimum capacity required ContingencyType and size of chiller Ancillary equipment System Issues and Challenges Location of equipmentAlternative Energy Sources Water and electrical connectionsAlternative fuel Plant ExpansionThermal storage Applications Outside the Chiller’s Range Retrofit OpportunitiesFlow rate out of range Precise temperature control System Issues and Challenges Temperatures out of rangePrecise temperature control, multiple chillers Chilled-water pump control Chilled water reset-raising and loweringSystem Controls Chilled-Water System ControlSystem Controls Critical valve reset pump pressure optimizationNumber of chillers to operate Chillers Difference Condenser-Water System ControlMinimum refrigerant pressure differential VFDs and centrifugal chillers performance at 90% loadCooling-tower-fan control Condenser-water temperature controlChiller-tower energy consumption Chiller-tower energy balanceChiller-tower-pump balance System Controls Variable condenser water flowEffect of chiller load on water pumps and cooling tower fans Decoupled condenser-water systemCDWP-2 Failure recovery Failure RecoveryConclusion Glossary Pumps system GlossaryGlossary Plant. Idea 88th Annual Conference Proceedings 1997 ReferencesEngineering July References102 Ashrae IndexIndex 105 106 Page Trane

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.