What Is Important? | Trane TRG-TRC016-EN specs

period four

Chiller-Plant Control

notes

What Is Important?

▲When to turn a chiller on or off

▲Which chiller to turn on or off

▲How to recover from an equipment failure

▲How to optimize system efficiency

▲How to communicate with the operator

Figure 89

There are primarily five issues to address in a chiller-plant control system.

1When should a chiller be turned on or off?

2After we know that a chiller must be turned on or off, which one should it be?

3If we attempt to turn on a chiller, pump, or cooling tower, and there is a malfunction, what do we do next?

4How can we minimize the energy cost of operating the system?

5How can the chiller-plant control system effectively communicate with the operator?

TRG-TRC016-EN

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Image 88

Trane TRG-TRC016-EN manual What Is Important?

Contents

Air Conditioning Clinic Chilled-Water Systems Business Reply Mail Comment Card One of the Systems Series One of the Systems Series Publication Trane Company Preface Contents Iii Types of Water Chillers Water systems Driving Sources Compressor-driven heat-driven Vapor-Compression Cycle Vapor-Compression Water Chillers Compressor Types Scroll Reciprocating Helical-rotarycentrifugal Variable-Speed Drives Air-Cooled or Water-Cooled Condenser TypesAir-Cooled or Water-Cooled Condensing Maintenance Low Ambient Operation Efficiency Comparison Packaged Air-Cooled Chiller Packaged or Split Components Remote Evaporator Barrel Remote Air-Cooled Condenser Indoor Air-Cooled Condenser Absorption Refrigeration Cycle Absorption Water Chillers Absorption Chillers Offer Choice Absorption Chiller Types Single-effectdouble-effect Direct-fired Equipment Rating Standards Equipment Rating StandardsAir-Conditioning & Refrigeration Institute ARI Integrated Part-Load Value Iplv Part-Load Efficiency RatingNon-Standard Part-Load Value Nplv Standard Rating Conditions Evaporator Condenser Rating Chiller type Flow rate Flow Rates and Temperatures QBtu/hr = 500 ⋅ flow rate ⋅ ∆T ARI conditions Low-flow conditions Electric Vapor-Compression Chillers ASHRAE/IESNA StandardEnergy Standard Water-Cooled Absorption Chillers Chiller type Capacity Ashrae Standard Chilled-Water System Design Chilled-Water System Components Chilled-Water System Load-Terminal Control Options Load-Terminal Control Three-Way Valve Control Two-Way Valve Control Face-and-Bypass Damper Control Three-way modulating valve Chiller Evaporator FlowConstant flow is most common Variable flow is possible Single-Chiller System Multiple-Chiller Systems Redundancy Part-load efficiency Parallel Configuration Single Pump Dedicated Pumps Percent flow Series Configuration Chillers Piped in Series Equal Set Points Staggered Set Points Primary-Secondary Configuration Primary-Secondary Decoupled Configuration Primary-Secondary System Rules Bypass pipe should be free of restrictions Production Loop Manifolded Production Pumps Distribution Loop Bypass pipe should be free of restrictions Load terminals should use two-way modulating control valves Varying Distribution Flow Variable-speed control riding the pump curve Multiple Distribution Pumps Distribution Tertiary Pumping Distribution Loop Characteristics Primary-Secondary System Rules System Operation Primary-Secondary System Operation Deficit Flow Excess Flow Control of Primary-Secondary System Pressure-based Types of Fluid Flow MetersTurbine and impeller Vortex Magnetic Ultrasonic Temperature-Based Calculations Electric Utility Deregulation Alternate Fuel Choice Fuel Choice Options Indirectly-coupled, gas-engine chillers Chiller Efficiency Improvements Low-Flow Systems Greater Focus on System Efficiency Trend Toward Lower Flow Rates Low-Flow Systems Variable-Primary-Flow Systems Variable-Primary-Flow Systems Critical VPF System Requirements Preferential Chiller Loading Preferential Loading Sidestream Configuration Heat-Recovery Chiller Heat Recovery Heat-Recovery Chiller Options Heat-recovery Auxiliary Dual condenser Condenser Heat pump Heat-Recovery Chiller Efficiency Mode Control of a Heat-Recovery Chiller Unloadingwith Asymmetric Design Asymmetric DesignDifferent chiller Capacities Different chiller Swing Chiller Chiller Free Cooling Free CoolingAirside economizer Waterside economizer Plate-and-Frame Heat Exchanger Refrigerant Migration Application Outside Range of Chiller Application Outside the Operating Range of the Chiller Chiller-Plant Control Chiller Controls What Is Important? Chiller Sequencing Chiller Sequencing Temperature Flow Capacity Chiller Rotation Small electric Chiller largeelectric chiller Heat Recovery Variable-Primary-Flow Systems System Failure Recovery Failure Recovery and Contingency PlanningMaintain flow of chilled water Keep it simple Notify the operator Allow the operator to intervene Contingency Planning System Timers System TuningLoad-confirmation timer Staging-interval timer Unload Before Start Soft Loading Chilled-Water Set Point Control System Optimization System Optimization Pros Chilled Water ResetCons Condenser-Water Temperature Tower Control of Condensing Pressure Operator Training and Support Operator Interface Operator Interface Ashrae Guideline Review-Period One Vapor-compression water chillers Review-Period Two Load-terminal control Review-Period Three Review-Period Four For more information, refer to the following references Quiz 109 Answers 111 Glossary 113 114 115 Trane Company