ASHRAE Fundamentals of Water System Design IP 2015

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Table of Contents Continuing Education Opportunities from the ASHRAE Learning Institute Self-Directed or Group Learning ASHRAE eLearning Preface Acknowledgments ASHRAE STAFF ASHRAE Learning Institute Special Publications Karen Murray Mark Owen Manager of Professional Editor/Group Manager of Development Handbook and Special Publications Martin Kraft Cindy Sheffield Michaels Managing Editor of Professional Managing Editor Development Matt Walker Associate Editor Sarah Boyle Assistant Editor Lauren Ramsdell Assistant Editor Michshell Phillips Editorial Coordinator For course information or to order additional materials, please contact: ASHRAE Learning Institute Telephone: 404/636-8400 1791 Tullie Circle, NE Fax: 404/321-5478 Atlanta, GA 30329 Web: www.ashrae.org/ali E-mail: [email protected] Errors or omissions in the data should be brought to the attention of Special Publications via [email protected]. Water System Design Concepts Water System Design Concepts Study Objectives Instructions Introductory Concepts Figure 1-1 Source/load. Figure 1-2 Source–distribution–load. Figure 1-3 Source–distribution–part-load. Figure 1-4 Hydronic system fundamentals (closed system). Figure 1-5 Cooling tower (open system). Figure 1-6 Low-temperature water system—direct or reverse return. Figure 1-7 Medium- or high-temperature water system. Figure 1-8 Chilled-water system—direct return piping. Figure 1-9 Condenser open water system (once through). Figure 1-10 Condenser cooling tower system inside reservoir or heated sump. Figure 1-11 Distribution orientation. Basic System Components Figure 1-12 Closed hydronic system fundamental components. Source Figure 1-13 Steam-to-water or water-to-water heat exchanger. Figure 1-14 Multiple chiller variable-flow chilled-water system. (1-1) Load Pump System Distribution System Expansion Chamber Design Trade-Offs System Temperatures Figure 1-15 Psychrometric chart chilled-water example. Heat Transfer in Hydronic Systems Sensible Heating or Cooling of Air (1-2) (1-3) Figure 1-16 Example system with heating coil. (1-4) Figure 1-17 Example system with heating coil. Figure 1-18 Latent Cooling and Dehumidification of Air Figure 1-18 Coil LMTD example. (1-5) (1-6) (1-7) Figure 1-19 Example system with cooling coil. Heat Transferred to or from Water (1-8) (1-9) (1-10) Load Systems Figure 1-20 Fan-coil unit. Figure 1-21 Typical coil. (1-11) Figure 1-22 Example process diagrammed on ASHRAE Psychrometric Chart. (1-12) Figure 1-23 Example of manufacturer’s coil selection program. Table 1-1 Coil Depth and Velocity to Achieve Dehumidification Figure 1-24 Heat transfer versus water flow for a coil. The Next Step Summary References Skill Development Exercises for Chapter 1 Complete these questions by writing your answers on the worksheets at the back of this book. 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 Piping System Design Piping System Design Study Objectives Instructions Basic Considerations Pressure Drop Figure 2-1 Bernoulli’s theorem. (2-1) Figure 2-2 Bernoulli’s piping example. Design Philosophy Figure 2-3 Direct-return piping. Figure 2-4 Reverse-return piping. Figure 2-5 Combination of direct and reverse systems. Figure 2-6 Piping expansion, offset piping. Figure 2-7 Piping expansion, mechanical joint. Sizing Piping (2-2) (2-3) Figure 2-8 Experimental arrangement for determining head loss in a pipe. (2-4) (2-5) Figure 2-9 Reynolds’s laminar versus turbulent flow demonstration. (2-6) Figure 2-10 Relation of Reynolds number, friction flow, and relative roughness for similar pipes. (2-7) Figure 2-11 Moody chart showing relationship between friction factors and Reynolds number for water flow. Figure 2-12 Friction factors and relative roughness for various pipes. Figure 2-13 Figure 2-13 Kinematic viscosity and Reynolds number determination nomogram. Figure 2-14 (2-8) (2-9) Figure 2-14 Friction loss for water in commercial steel pipe (Schedule 40) and friction loss for water in copper tubing (Types K, L, M). (2-10) Flow-Rate Measurement Direct and Indirect Flow Measurement Methods Table 2-1 Friction Loss for Water in Feet for 100 ft, 2 in. Nominal Pipe Schedule 40 Table 2-2 Volumetric or Mass Flow-Rate Measurement Venturi, Nozzle, and Orifice Flowmeters Figure 2-15 Typical Herschel-type Venturi meter. Figure 2-16 Dimensions of ASME long-radius flow nozzles. Figure 2-17 Sharp-edge orifice with pressure tap locations. (2-11) (2-12) (2-13) Variable-Area Flowmeters (Rotameters) Figure 2-18 Variable-area flowmeter. Turbine Flowmeters The Next Step Summary References Skill Development Exercises for Chapter 2 Complete these questions by writing your answers on the worksheets at the back of this book. 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 Pipe Materials and Fittings Pipe Materials and Fittings Study Objectives Instructions Pipe Materials Metal Pipe Steel Pipe Table 3-1 Allowable Stressesa for Pipe and Tube Copper Tube Table 3-2 Steel Pipe Data Table 3-3 Copper Tube Data Table 3-4 Internal Working Pressure for Copper Tube Joints Ductile Iron and Cast Iron Pipe Joining Methods for Metal Pipe Threading Soldering and Brazing Flared and Compression Joints Flanges Welding Reinforced Outlet Fittings Other Joints Threaded Unions Special Systems Plastic Pipe Allowable Stresses Table 3-5 Properties of Plastic Pipe Materialsa (3-1) Plastic Material Selection Table 3-6 Manufacturers’ Recommendations for Plastic Materialsa,b Corrosion Valves and Fittings (3-2) Table 3-7 K Factors—Threaded Pipe Fittings Table 3-8 K Factors—Flanged Welded Pipe Fittings Table 3-9 Approximate Range of Variation for K Factors Figure 3-1 Resistance coefficients like Figure 3-2 for valves and fittings. Figure 3-2 Resistance coefficients for valves and fittings. Figure 3-3 Resistance coefficients for increasers and diffusers. Figure 3-4 Resistance coefficients for reducers. Backflow Prevention Devices Figure 3-5 Backflow prevention device. Selection of Devices Installation of Devices Pipe Selection 1. Recalling that pipe selection guidelines suggest keeping friction loss less than 4 ft/100 ft and design velocity greater than 2 fps, Table 2-1 allows the designer to plot out a preliminary pipe selection. For 40 gpm, limited by a head loss of 4 ft... Figure 3-6 Pipe loop sizing example. 2. Determine the pressure loss due to friction for the 300 ft of piping: Dhf = 300 ft × 2.88 ft/100 ft = 8.4 ft Dhf = 1.15 × 8.4 ft = 9.66 ft 3. Calculate the PD for the gate valve. Looking at Tables 3-7 and 3-8, K for a 2 in. gate valve is 0.17. Figure 3-7 Pipe sizing using friction loss chart. 4. Determine the PD due to the 90° regular pattern elbows PD we know: 5. Similarly, the PD for the tee joints is as follows: 6. The total PD is the sum of all component contributions. Total Dhf = coil + pipe + balance valve + control valve + gate valve + tee branches + elbows = (3.0 ft) + (9.66 ft) + (2.31 ft) + (8.34 ft) + (0.04 ft) + (0.64 ft) + (0.91 ft) = 24.89 ft System Characteristic Curve Figure 3-8 Exponential curve of flow versus pressure drop. Figure 3-9 Curve rotates counterclockwise as the valve closes. Figure 3-10 Open-system diagram. Figure 3-11 Change in curve because of elevation difference. Figure 3-12 Data for plotting Figure 3-11. The Next Step Summary Bibliography Skill Development Exercises for Chapter 3 Complete these questions by writing your answers on the worksheets at the back of this book. 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 3-9 3-10 Centrifugal Pumps Study Objectives Instructions Types of Pumps Common Applications Figure 4-1 Diagram of a CHW system. Figure 4-2 Condenser water circuits to cooling tower. Figure 4-3 Boiler feed and condensate return pumping. Figure 4-4 Driver for HVAC pumps. Operation Figure 4-5 Vanes directing fluid. Figure 4-6 Vanes are inclined backward. Figure 4-7 Energy captured and directed through the impeller enclosure, called a volute. Figure 4-8 Centrifugal pump, impeller, and volute. Figure 4-9 Impeller action on fluid. (4-1) Equipment Figure 4-10 Variety of impeller shroud shape characteristics. Source: HI 1994. Figure 4-11 Single- and double-suction impellers. Typical Pump Configurations Figure 4-12 Circulator pump. Figure 4-13 Close-coupled end-suction pump. Figure 4-14 Frame-mounted end-suction pump. Figure 4-15 Vertical inline pump. Figure 4-16 Base-mounted horizontal split-case pump. Figure 4-17 Vertical turbine pump, wet sump arrangement. Pump Nomenclature Pump Selection Centrifugal Pump Characteristics Figure 4-18 Manufacturer’s pump curve. Figure 4-19 Head–capacity curve. Figure 4-20 Flat versus steep pump curve. Figure 4-21 Characteristic curves for pump models at given speed. Figure 4-22 Selected pump head–capacity curve. Figure 4-23 System curve and pump head–capacity curve. Pump Horsepower Water Horsepower (4-2) (4-3) Figure 4-24 Comparing the increase of WHP as the pump increases flow. (4-4) Brake Horsepower Figure 4-25 BHP on the pump curve above the pump head curve. (4-5) Pump Efficiency (4-6) Figure 4-26 Increase of pumping power required with pump flow. Figure 4-27 Pump efficiency curves. Figure 4-28 Recommended selection regions. Figure 4-29 Pump performance data. Figure 4-30 Pressures on impeller causing radial thrust. Figure 4-31 Change in radial thrust versus pumping rate. Radial Thrust NPSH Figure 4-32 Selected pump curve showing NPSHR. (4-7) Figure 4-33 NPSHA in a proposed installation. (4-8) Figure 4-34 NPSHA in an existing installation. Figure 4-35 Factory test setup to determine pump’s NPSHR. Pump Selection Process 1. Determine the load to be pumped (heating or cooling) in Btu/h. 2. Determine the design Dt across the water side of the load heat transfer coil or device. For example, 20°F drop for heating or 12°F rise for cooling. Calculate the required flow in gpm for each load. 3. Total the zone load flows to determine the total flow in gpm. 4. For the secondary pump, select the most resistant path within the secondary distribution and terminal piping. 5. Determine the method of mechanically mounting and supporting the pump on a pad in the equipment room, inline in the piping, or within a well or wet sump below floor level. 6. With the total head (in feet drop) and capacity (in gpm) determined, select a pump from the manufacturer’s family curves and the mounting required. Figure 4-36 Pump selection process. 7. Refer to the manufacturer’s individual pump performance curve sheet showing pump efficiency, impeller diameter size, brake horsepower, and NPSHR. Select a flat curve pump for closed systems with control valves (to minimize variation in head for ... System Design Considerations Similarity Relationships: The Affinity Laws Table 4-1 Equations for Speed Change and Impeller Diameter Change Table 4-1 Equations for Speed Change and Impeller Diameter Change Parallel Pumping Figure 4-37 The old way: sketching the composite parallel pump curve by hand. Figure 4-38 The new way: sketching the composite parallel pump curve by spreadsheet. Pumps in Series Figure 4-39 An example with two full-sized pumps. Figure 4-40 Illustration of pump and system curves applied in parallel or in series and relative system flow effects. Figure 4-41 Schematic modifications example to place pumps in series. Variable-Speed Pumping Figure 4-42 Example of pump curves at varying pump speeds. Figure 4-43 Schematic of simplified variable-speed-pump-controlled system. Figure 4-44 Typical constant-speed pump curve interaction with variable-speed pump. Figure 4-45 Flow coefficient method of calculating balanced and unbalanced conditions. Figure 4-46 System curve for variable-speed pumping. Figure 4-47 Control area curve for example. Figure 4-48 Calculation of total dynamic head for area curve due to valve change of states. Figure 4-49 Control area curve with system curve overlaid. The Next Step Summary References and Bibliography Skill Development Exercises for Chapter 4 Complete these questions by writing your answers on the worksheets at the back of this book. 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13 Terminal Unit Performance and Control Study Objectives for Chapter 5 Instructions Types of Terminals Water Supply Systems to Terminals Two-Pipe System Figure 5-1 Two-pipe source/load concept. Three-Pipe System Four-Pipe System Figure 5-2 Four-pipe dual-temperature water system. Performance and Control Figure 5-3 Space heat transfer in proportion to outdoor temperature. Figure 5-4 As outdoor temperature increases, hot-water flow decreases. Controlling Water Flow Figure 5-5 Flow control using two-way valve. Types of HVAC Control Valves Figure 5-6 Flow control using three-way valve. Figure 5-7 Two-pipe control valve body–single and double seat. Figure 5-8 Three-way control valves—mixing and diverting types. Globe Valves Ball Valves Figure 5-9 Actuated ball valve. Butterfly Valves Other Valves Hydronic Accessories Determining Valve Flow Rate (5-1) (5-1) System Control Characteristics Figure 5-10 Nonlinear heat transfer versus water flow in hydronic coil. Figure 5-11 Core flow characteristics for a valve. Equal Percentage Characteristic (5-2) Figure 5-12 Valve flow characteristic. Valve Rangeability Valve Authority (5-3) Figure 5-13 Distortion effect of low control valve authority caused by low pressure drop. (5-4) (5-5) (5-6) Modulating Control Figure 5-14 Chilled-water coil heat transfer versus water flow. Figure 5-15 Ideal combination of equal percentage valve curve with water coil emission curve. Figure 5-16 Control effect of valve authority. Two-Position Control Figure 5-17 Two-position control. Figure 5-18 Modulating proportional control. Proportional and Proportional Integral Control Figure 5-19 Proportional integral (PI) control. System Control Configurations Figure 5-20 Primary/secondary pumping with two-way valve. Figure 5-21 Primary/secondary with check valve in common. Figure 5-22 Primary/secondary with valve in common and differential pressure transmitter monitoring flow. Figure 5-23 Primary/secondary with temperature sensors in bridge. Figure 5-24 Terminal with face bypass control. Figure 5-25 Terminal with face bypass control and conditioned bypass air. Figure 5-26 Variable supply water temperature for part-load conditions. Pressure-Independent Control Valves Figure 5-27 Linear control characteristic. Figure 5-28 Fluid-system-powered regulator. Variable-Speed Circulator on Coil Figure 5-29 Differential pressure regulator in same body as temperature control valve. Figure 5-30 Variable-speed circulator on coil. The Next Step Summary References Skill Development Exercises for Chapter 5 5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9 5-10 5-11 5-12 5-13 5-14 Expansion Tanks and Air Elimination Expansion Tanks and Air Elimination Study Objectives Instructions Open and Closed Water Systems Typical Open System Figure 6-1 Typical open water system. Typical Closed System Figure 6-2 Typical hydronic system. Hydronic Accessories Pressure Relief Valve Pressure-Reducing Valve Figure 6-3 Pressure-reducing valve. Expansion Tank Figure 6-4 Expansion tanks. Figure 6-5 Closed tank. Figure 6-6 Expansion of water above 40°F. Figure 6-7 Tank pressure related to system pressure. Figure 6-8 Point of no pressure change. Air Elimination Air Separation Figure 6-9 Internal operating mechanism for automatic air vent. Figure 6-10 Automatic or manual air vents in system zones or coils for small pipe sizes. Figure 6-11 Dynamic air separator. Figure 6-12 Air separator. Figure 6-13 Diaphragm expansion tank. Figure 6-14 Compression tank. Figure 6-15 Tank location for primary/secondary or compound pumping systems. Sizing Expansion Tanks Figure 6-16 Pressure effects of alternative tank locations: (a) pump suction side and (b) pump discharge side. (6-1) Figure 6-17 Henry’s constant versus temperature for air and water. (6-2a) Figure 6-18 Solubility versus temperature and pressure for air-water solutions. Table 6-1 Volume of Water in Standard Pipe and Tube (6-2b) Pressure and Temperature Considerations Figure 6-19 Flowchart for sizing expansion tanks. The Next Step Summary References Skill Development Exercises for Chapter 6 6-1 6-2 6-3 6-4 6-5 6-6 6-7 6-8 6-9 6-10 6-11 6-12 6-13 Piping System Development Study Objectives Instructions Piping System Design 1. Know the building heat transfer load. In the initial approach, all aspects of the load must be known. What is the total load? How is the load distributed by time and location? How are controlled occupancy zones determined or laid out? As the syste... Figure 7-1 Typical building layout. 2. Determine the heating and cooling loads based upon occupancy, comfort requirements, codes, and standards (see ANSI/ASHRAE/IES Standard 90.1 and 90.1 User’s Manual), and determine any special requirements for facilities like computer rooms, labor... 3. Develop a concept for part-load control: Figure 7-2 Determine the loads and consult references. 4. Develop the piping and pumping system concept (see Figure 7-3), such as the following: Consider modeling the system to determine the full- and part-load flows, the pressure distribution required, and this effect on components. 5. Develop a first-cost analysis versus energy operating costs over the projected life of the system. 6. Determine the maintenance and operating requirements and if they match with the personnel capabilities. Figure 7-3 Develop piping/pumping system concept. Direct-Return Analysis Figure 7-4 Piping system design flowchart. Figure 7-5 System requiring four AHUs, each with 100 gpm load. Figure 7-6 Coil connections. Figure 7-7 Friction loss, schedule 40 steel pipe. Table 7-1 Schedule 40 Steel Pipe (3 in. Nominal Discharge) Table 7-2 Schedule 40 Steel Pipe (4 in. Nominal Discharge) Table 7-3 Schedule 40 Steel Pipe (5 in. Nominal Discharge) Table 7-4 Unit 1 Supply and Return Sides Figure 7-8 Direct-return piping layout. Table 7-5 Direct Return for Units 1, 2, 3, and 4 Table 7-6 Lower Coil Pressure Drop Selected for Units 1, 2, 3, and 4 Reverse-Return Analysis Figure 7-9 Reverse-return piping layout. Table 7-7 Reverse-Return Piping Arrangement for Units 1, 2, 3, and 4 Summary Summary of Pumping Horsepower— Direct Return Versus Reverse Return Table 7-8 Lower Pressure Drop Coil for Units 1, 2, 3, and 4 Table 7-9 Direct and Reverse Return with Balanced and Unbalanced Flow Table 7-10 Summary of Direct and Reverse Return Primary/Secondary Analysis Figure 7-10 Two-way valve in connecting bridge return with secondary pump. Figure 7-11 Primary/secondary pumping. Table 7-11 Pressure Drop from Main to Secondary Bridge for Units 1, 2, 3, and 4 Table 7-12 Pressure Drop in Typical Secondary Loop Types of Pumps and Valves Figure 7-12 Flat versus steep pump characteristics. Effects of Control Valves Primary/Secondary Application Study Figure 7-13 Four-zone heating system. Table 7-13 Four-Zone Heating System Figure 7-14 Primary/secondary pumping, four-zone heating system. Table 7-14 3 hp Motor Selected Figure 7-15 Primary/secondary bridge energy. Table 7-15 Primary/Secondary Bridge Energy Figure 7-16 Primary/secondary pumping, four-zone heating system. Antifreeze Solutions for Low-Temperature Applications Figure 7-17 Coil with glycol heat exchanger and pump for low temperatures. Figure 7-18 Pumped coil with face bypass dampers for low-temperature primary/secondary pumping. (7-1) Figure 7-19 Specific heats of aqueous solutions of industrially inhibited ethylene glycol (percent by volume). Figure 7-20 Specific heats of aqueous solutions of industrially inhibited propylene glycol (percent by volume). Pumping Design Factors Figure 7-21 One-shot chemical feeder. The Next Step Summary References and Bibliography Skill Development Exercises for Chapter 7 7-1 7-2 7-3 7-4 7-5 7-6 7-7 7-8 7-9 7-10 7-11 7-12 7-13 7-14 7-15 7-16 7-17 Matching Pumps to Systems Study Objectives Instructions Matching the Pump to the System Figure 8-1 Typical open-system system curve. Source: ASHRAE Handbook—HVAC Systems and Equipment (2012). Figure 8-2 Pump curve and system curve intersection. Figure 8-3 System with cooling tower. Figure 8-4 Cooling tower curves. System Curves (8-1) Series Flow Coefficients (8-2) (8-3) (8-4) (8-5) (8-6) (8-6) Table 8-1 Theoretical Equal Percentage Control Valve Data for Example 8-1 Figure 8-5 Valve flow versus lift for Example 8-1. Parallel Flow Coefficients Figure 8-6 Head versus flow for pump serving three circuits. (8-7) Table 8-2 Balanced Path Example Table 8-3 Unbalanced Path Example Parallel Pumping Figure 8-7 Unbalanced system curve intersection point with pump curve. Figure 8-8 Effects of larger distribution pipes and resized coils and control valves. Figure 8-9 Pump curve developed on paralleled pump curve line A-B-C. Figure 8-10 Pump motor sized to prevent overloading during single pump operation. Figure 8-11 Piping schematic of parallel pumps. Series Pumping Figure 8-12 Pump curve for series operation. Figure 8-13 Piping schematic of series pumps. Figure 8-14 Operating conditions for series pump installation. Standby Pumps Figure 8-15 Piping schematic of standby pump. Trimming Pump Impellers and Adjusting Pump Speed Figure 8-16 Pump operating points. Two-Speed Pumping Figure 8-17 Two-speed pumping. Figure 8-18 Typical performance curve—6 in. suction × 8 in. discharge × 9.5 in. impeller. Pumps with Two-Speed Motors (Stethem 1988) Figure 8-19 Two-speed pumping example. Table 8-4 Four Flow Selection Steps to Reduce Pumping Power Variable-Speed Pumping Figure 8-20 Typical direct-return system. Figure 8-21 Head loss with two-way valves at full load and 50% part load. Figure 8-22 Proportional controller and adjustable-frequency drive controlling pump. Figure 8-23 Direct-return system with sensor/transmitter located at end of last riser. Figure 8-24 Differential pressure control curve above piping friction loss. Figure 8-25 Pump curve showing head reduction with change in pump speed. Figure 8-26 Pump curve showing pumping power reduction with change in pump speed. Source Distribution Pumping Figure 8-27 Primary/secondary pumping concept. Figure 8-28 Main-source primary/secondary variable-speed pumping. Figure 8-29 Distributed variable-speed pumping. The Next Step Summary References and Bibliography Skill Development Exercises for Chapter 8 8-1 8-2 8-3 8-4 8-5 8-6 8-7 8-8 8-9 Water Chillers and Load Control Study Objectives Instructions Basic Water Chiller Components Refrigeration Cycle Figure 9-1 Basic components of liquid chilling system. Figure 9-2 Schematic of simple liquid chilling system. Figure 9-3 Pressure-enthalpy diagram for a refrigerant. Figure 9-4 Simplified pressure-enthalpy diagram for a refrigerant. Figure 9-5 Refrigeration cycle shown on simplified pressure-enthalpy diagram. Heat Transfer Chiller (9-1) (9-2) (9-3) (9-4) (9-5) (9-6) (9-7) Solution Solution Refrigeration Power Chiller Types and Control Figure 9-6 General guideline of the types of chillers available for air conditioning. Source: ASHRAE Handbook—Refrigeration (2014). Figure 9-7 Centrifugal compressor cross section. Figure 9-8 Section of single-screw refrigeration compressor. Figure 9-9 Sequence of compression process in single-screw compressor. Figure 9-10 Vertical, discharge-cooled, hermetic twin-screw compressor. Figure 9-11 Scroll compression process. Source: Purvis (1987). Figure 9-12 Bearings and Other Components of Scroll Compressor Source: Elson et al. (1990). Figure 9-13 Reciprocating compressor refrigeration system. Figure 9-14 Two-shell lithium bromide cycle water chiller. Figure 9-15 Schematic of double-effect, direct-fired absorption chiller with reverse parallel flow cycle. Figure 9-16 Comparison of single-stage centrifugal, reciprocating, and screw compressor performance. Figure 9-17 Reciprocating liquid chiller performance with three equal steps of unloading. Figure 9-18 Parallel arrangement: water to be chilled is divided among liquid chillers and combined again in common header after chilling. Figure 9-19 Series arrangement. Figure 9-20 Chillers piped in parallel in primary production loop. Figure 9-21 Schematic showing constant- and variable-flow arrangements. Chiller Piping Arrangements Figure 9-22 Three chillers in parallel, each with a dedicated constant-speed pump. Figure 9-23 Parallel arrangement with common bridge between load and production sections. Figure 9-24 Parallel arrangement with common bridge at opposite end of production section. Figure 9-25 Primary/secondary allows for simple addition of extra chillers and loads. Figure 9-26 Pumping system manifolded to sources gives flexibility for maintenance and failure operation modes as well as capability to provide more system flow. Chiller Energy Performance Figure 9-27 Chiller performance improvement versus percent load. Figure 9-28 Chiller, control, and pumping alternatives versus design temperature rises. Figure 9-29 Relationship between chiller power consumption and variable-speed pump power consumption. Thermal Storage Figure 9-30 Schematic of thermal storage concept using ice builder with a chilled-water system. Summary References Skill Development Exercises for Chapter 9 9-1 9-2 9-3 9-4 9-5 9-6 9-7 9-8 9-9 Skill Development Exercises for Chapter 1 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 1-10 1-11 Skill Development Exercises Skill Development Exercises Skill Development Exercises for Chapter 2 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 Skill Development Exercises for Chapter 3 3-1 3-2 3-3 3-4 3-5 3-6 3-07 3-8 3-9 3-10 3-10 Diagram for exercise 3-10. Skill Development Exercises for Chapter 4 4-1 4-2 Centrifugal Pump. 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-10 4-11 4-12 4-13 Skill Development Exercises for Chapter 5 5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9 5-10 5-11 5-12 5-13 5-14 Skill Development Exercises for Chapter 6 6-1 6-2 6-3 6-4 6-5 6-6 6-7 6-8 6-9 6-10 6-11 6-12 6-13 Skill Development Exercises for Chapter 7 7-1 7-2 7-3 7-4 7-5 7-6 7-7 7-8 7-9 7-10 7-11 7-12 7-13 7-14 7-15 7-16 7-17 Skill Development Exercises for Chapter 8 8-1 8-2 8-3 8-4 8-5 8-6 8-7 8-8 8-9 Skill Development Exercises for Chapter 9 9-1 9-2 9-3 Figure 9-1 Diagram for Exercise 9-3. 9-4 9-5 9-6 9-7 9-8 9-9