Trane SYS-APM001-EN manual Preferential loading series arrangement, Sidestream system control

Page 82

Chilled-Water System Variations

Sidestream system control

The flexibility of sidestream applications is increased by the fact that the devices are used to pre-cool return water, not to produce the system chilled- water temperature. This means that they may be loaded by a different signal. In the case of a plate-and-frame heat exchanger, as long as return water is being cooled, there is an advantage to using it. A heat-recovery chiller can be loaded to produce just the amount of hot water necessary using the condenser-water leaving temperature as a signal. If preferential loading is used with an absorption chiller, it may be loaded simply by decreasing its leaving-water temperature.

Sidestream configurations may also be used to preferentially load chillers or a heat exchanger used in a variable-primary-flow system, or to isolate chillers that are incapable of the same flow variations as the rest of the system.

Preferential loading – series arrangement

As previously discussed in “Series Chillers” on page 44, preferential loading is very simple when chillers are placed in series. If both the upstream and downstream chillers are given the system leaving water temperature setpoint, the upstream chiller is preferentially loaded and the downstream chiller operates whenever the upstream chiller can no longer achieve setpoint. If the downstream chiller is given the system setpoint, and the upstream chiller is given a warmer setpoint, then the downstream chiller loads first. Another method for preferential loading uses compressor RLA to determine when to bring on the next chiller.

Figure 47. Preferential loading - series arrangement

 

 

56°F [13.3°C]

49°F [9.4°C]

 

42°F [5.5°C]

 

 

 

Chiller 2

Chiller 1

 

 

setpoint = 42°F [5.5°C]

 

 

setpoint = 42°F [5.5°C]

 

Loads

76

Chiller System Design and Control

SYS-APM001-EN

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Contents May Page Chiller System Design and Control Preface Contents 100 Primary System Components ChillerPrimary System Components Chiller evaporatorEffect of chilled-water temperature Effect of chilled-water flow rate and variationWater-cooled condenser Effect of condenser-water temperatureEffect of condenser-water flow rate Air-cooled versus water-cooled condensers MaintenanceAir-cooled condenser Packaged or Split System?Low-ambient operation Energy efficiencyLoads Air-cooled or water-cooled efficiencyThree-way valve load control Two-way valve load controlVariable-speed pump load control Face-and-bypass dampersChilled-Water Distribution System Chilled-water pumpPump per chiller Distribution pipingManifolded pumps Pumping arrangements Constant flow systemPrimary-secondary system Condenser-Water SystemCooling tower Variable-primary systemEffect of ambient conditions on cooling tower performance Condenser-water pumping arrangementsEffect of load on cooling tower performance Single tower per chillerChiller control Unit-Level ControlsRecommended chiller-monitoring points per Ashrae Standard Centrifugal chiller capacity control Centrifugal chiller with AFDAFD on both chillers Application Considerations Small Chilled-Water Systems 1-2 chillersVariable flow Application Considerations Constant flowCondensing method Parallel or series Application ConsiderationsNumber of chillers Part load system operationManaging control complexity Mid-Sized Chilled-Water Systems ChillersPreferential vs. equalized loading and run-time Large chilled-water system schematic Large Chilled-Water Systems + Chillers, District CoolingPipe size PowerWater Chiller Plant System Performance Chiller performance testingLimitations of field performance testing ControlsSYS-APM001-EN SYS-APM001-EN System Design Options Guidance for Chilled- and Condenser-Water Flow RatesStandard 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 DP2/DP1 = Flow2/Flow11.85 Low-flow conditions for cooling tower Base Case Low FlowTotal system power Component Power kW Base Case Low Flow System summary at full loadCoil response to decreased entering water temperature Chilled water system performance at part loadSmaller tower Entering fluid temperature, F CCooling-tower options with low flow System designΔT2 = 99.1 78 = 21.1F or 37.3 25.6 = 11.7C Same tower, smaller approachSame tower, larger chiller Same tower, smaller approach Present Smaller ApproachRetrofit opportunities Retrofit capacity changes Larger Present Chiller Same towerCost Implications Misconceptions about Low-Flow Rates Misconception 1-Low flow is only good for long piping runsKWh SYS-APM001-EN System Configurations Parallel ChillersSystem Configurations Parallel chillers with separate, dedicated chiller pumpsSeries Chillers Series chillersPrimary-Secondary Decoupled Systems Hydraulic decouplingCheck valves System Configurations Production Production loopSystem Configurations Distribution Distribution-loop benefits of decoupled system arrangementCampus CommonTertiary or distributed Decoupled system-principle of operation Tertiary pumping arrangementFlow-based control Temperature-sensingFlow-sensing Adding a chiller Multiple chilled-water plants on a distribution loopSubtracting a chiller Pump control in a double-ended decoupled system Double-ended decoupled systemChiller sequencing in a double-ended decoupled system Variable-Primary-Flow Systems Other plant designsAdvantages of variable primary flow Operational savings of VPF designsChiller selection requirements Dispelling a common misconceptionFlow, ft.water Flow rate Managing transient water flows Flow-rate changes that result from isolation-valve operationSystem Configurations System design and control requirements Effect of dissimilar evaporator pressure dropsAccurate flow measurement Chiller sequencing in VPF systems Bypass flow controlAdding a chiller in a VPF system Flow-rate-fluctuation examplesSubtracting a chiller in a VPF system Sequencing based on loadOther VPF control considerations Select slow-acting valves to control the airside coilsPlant configuration Consider a series arrangement for small VPF applicationsGuidelines for a successful VPF system Chiller selectionChiller sequencing Plant configurationBypass flow Airside controlCondenser Free Cooling or Water Economizer Heat RecoveryChilled-Water System Variations Plate-and-frame heat exchangerChilled-Water System Variations Refrigerant migrationRefrigerant migration chiller in free-cooling mode Well, river, or lake waterPreferential Loading Preferential loading parallel arrangementPreferential loading sidestream arrangement Sidestream plate-and-frame heat exchangerSidestream with alternative fuels or absorption Chilled-Water System VariationsPreferential loading series arrangement Sidestream system controlSeries-Counterflow Application Series-series counterflowEvaporators Unequal Chiller SizingCondensers Low ΔT Syndrome System Issues and ChallengesAmount of Fluid in the Loop System response to changing conditions System Issues and ChallengesChiller response to changing conditions ExampleMinimum capacity required ContingencyType and size of chiller Water and electrical connections System Issues and Challenges Location of equipmentAlternative Energy Sources Ancillary equipmentAlternative fuel Plant ExpansionThermal storage Applications Outside the Chiller’s Range Retrofit OpportunitiesFlow rate out of range System Issues and Challenges Temperatures out of range Precise temperature controlPrecise temperature control, multiple chillers Chilled-Water System Control Chilled water reset-raising and loweringSystem Controls Chilled-water pump controlSystem Controls Critical valve reset pump pressure optimizationNumber of chillers to operate VFDs and centrifugal chillers performance at 90% load Condenser-Water System ControlMinimum refrigerant pressure differential Chillers DifferenceCondenser-water temperature control Cooling-tower-fan controlChiller-tower energy balance Chiller-tower energy consumptionSystem Controls Variable condenser water flow Chiller-tower-pump balanceDecoupled condenser-water system Effect of chiller load on water pumps and cooling tower fansCDWP-2 Failure Recovery Failure recoveryConclusion Glossary Glossary Pumps systemGlossary References Plant. Idea 88th Annual Conference Proceedings 1997References Engineering July102 Index AshraeIndex 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.
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