109 | Trane TRG-TRC016-EN instruction

Quiz

Questions for Period 3

9Why does a variable-primary-flow (VPF) system require a bypass in the system?

10Identify one scenario where preferential loading is beneficial to a chilled-water system.

11What is the benefit of using a smaller-capacity “swing” chiller in a multiple-chiller system?

Questions for Period 4

12Making decisions about when to turn chillers on and off is commonly referred to as chiller __________.

13Lowering the temperature of the water leaving the cooling tower __________

(increases or decreases) the energy consumption of the chiller and

__________ (increases or decreases) the energy consumption of the cooling tower fans.

14An increase in the condenser approach temperature (that is, the temperature difference between the water and the refrigerant inside the condenser) may be a sign of what?

TRG-TRC016-EN

109

Image 116

Trane TRG-TRC016-EN manual 109

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 Condensing Condenser TypesAir-Cooled or Water-Cooled 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 Air-Conditioning & Refrigeration Institute ARI Equipment Rating StandardsEquipment Rating Standards Non-Standard Part-Load Value Nplv Part-Load Efficiency RatingIntegrated Part-Load Value Iplv 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 Energy Standard ASHRAE/IESNA StandardElectric Vapor-Compression Chillers 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 Constant flow is most common Variable flow is possible Chiller Evaporator FlowThree-way modulating valve 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 Turbine and impeller Vortex Magnetic Ultrasonic Types of Fluid Flow MetersPressure-based 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 Airside economizer Waterside economizer Free CoolingFree Cooling 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 Cons Chilled Water ResetPros 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