140P2022R0019-0006_Att01a_RevSpec236413-WaterCooledChillers_220317_0006.pdf

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06042021 WATER-COOLED CHILLERS

SECTION 23 64 13 – WATER-COOLED CHILLERS

PART 1 - GENERAL

1.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary

Conditions and Division 01 Specifications, apply to this Section.

1.2 SUBMITTALS

A. Product Data: The following data shall be provided in the submittal:

1. Manufacturer's standard catalog information

2. Sample ARI 550/590 test report (latest version)

3. Chiller model number

4. Refrigerant type

5. Capacity

6. NPLV, total kW input, kW/ton, and COP at 100% rated capacity and like part load performance data at 25%, 50%, and 75% of rated capacity for AHRI conditions and specified operating conditions.

7. Evaporator:

a. Entering-water temperature

b. Leaving-water temperature

c. Fouling factor

d. Design water flow rate, minimum, and maximum flow rate

e. Water pressure drop at design flow rate

f. Number of passes

g. Insulation type and thickness

h. Evaporator unit:

1) Tube material

2) Tube diameter

3) Tube thickness

4) Pull space required and on which end of the chiller

8. Water-cooled Condenser:

a. Rated entering-water temperature

b. Minimum allowable entering water temperature

c. Design water flow rate and maximum water flow rate

d. Number of passes

e. Fouling factor

f. Water pressure drop at design flow rate

g. Water temperature rise at rated entering temperature and rated load

h. Condenser unit:

1) Tube material

2) Tube diameter

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3) Tube thickness

4) Pull space required and on which end of the chiller

9. Compressor rpm and type

10. Casing material

11. Connection sizes and types

12. Motor data for compressor (and oil pump when applicable):

a. Manufacturer

b. NEMA frame size (open drive)

c. Rated hp

d. Service factor

e. Volts/phase

f. Full load current

g. rpm

h. Power factor

13. VSD:

a. Manufacturer

b. Size

c. Type

d. Wiring diagram

B. Shop Drawings, Physical data:

1. Overall dimensions

2. Empty weight

3. Operating weight

4. Drawings shall be certified for construction

C. Wiring Diagrams: Complete and edited wiring diagrams, not partial or disconnected diagrams.

The diagrams shall include detailed controls diagrams and ladder diagrams suitable for the intended application.

D. Close-out Submittals: Include submittal information listed in Product Data.

1.3 QUALITY ASSURANCE

A. Qualifications: A State of Pennsylvania Registered Refrigeration Technician shall perform all work associated with evacuation, charging, refrigerant recovery, and start-up of the chiller compressor.

B. Regulatory Requirements: Codes: All work, materials, and equipment shall comply with the rules and regulations of the following codes and the state electrical and plumbing authorities.

Such codes, where applicable, shall take precedence over these plans and specifications. As a minimum, the installation shall comply with the

1. EPA Clean Air Act

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2. ASHRAE Compliance:

a. ASHRAE 15 for safety code for mechanical refrigeration.

b. ASHRAE 147 for refrigerant leaks, recovery, and handling and storage requirements.

3. ASHRAE/IESNA Compliance: Applicable requirements in ASHRAE/IESNA 90.1-2007, Section 6 - "Heating Ventilating and Air Conditioning."

4. ARI 550/590, "Standard for Water Chilling Packages Using the Vapor Compression

Cycle."

C. Certifications:

1. Chiller shall be UL or ETL-labeled.

2. Actual chiller performance and capacities shall be certified per ARI Standard 550/590.

3. Manufacturer's field inspection report (See Field Quality Control).

1.4 WARRANTY

A. Refer to Division 23 Section “Common Work Results for HVAC," for general warranty requirements.

B. Manufacturer's Special Warranty on Compressor: Written 5 years warranty, signed by manufacturer agreeing to repair or replace compressor, including all parts, labor, and replacement of oil and refrigerant charge.

PART 2 - PRODUCTS

2.1 OPERATING CONDITIONS

A. Provide water-cooled liquid chiller(s) with the capacity as scheduled on drawings at job site elevation.

B. Chiller(s) shall be designed to operate using R-134a, or R-514A.

C. Chillers shall be designed for parallel evaporator water flow.

D. The liquid to be chilled will be water containing corrosion inhibitors.

E. The fouling factor for the evaporator shall be 0.0001 and the condenser shall be 0.00025.

2.2 CENTRIFUGAL CHILLER

A. Available manufacturers are Trane, York: A Johnson Controls Inc. Company, or equal equipment by another manufacturer that meets all of the requirements listed below:

1. Performance at the water temperatures and flows listed on the chiller schedule on the drawings

2. Dimensions: Water box length no longer than 15’ for any of the three chillers, water box width no wider than 7’ for the 750 ton chillers, 5’6” for the 350 ton chiller.

3. Refrigerant charge in the largest circuit - Requiring less than 4,000 CFM of machine room ventilation without modification to the existing exhaust fan, up to 4,400 CFM with fan modifications

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4. Electrical requirements – Power requirements for the 750 ton chillers must be less than the following: KW = 510, MCA = 830, Fuse size 1200 amps or smaller coordinated with electrical properties of the chiller per NEC. Power requirements for the 350 ton chiller must be less than the following: KW = 250, MCA = 385, Fuse size 600 amps coordinated with electrical properties of the chiller per NEC.

B. Refer to the project construction drawings for the required arrangement of the condenser and evaporator for each chiller as the arrangement for each chiller is unique.

C. Provide UL- or ETL-listed water chiller(s) consisting of a semi-hermetic or open drive centrifugal compressor, evaporator, water-cooled condenser, and factory-wired control panel.

D. Compressor shall have the following features:

1. Compressor casing shall be cast iron with single- or multiple-volute casings of such design that excessive loads cannot be placed on shafts, bearings, or seals during assembly or disassembly.

2. Lubrication System:

a. A direct drive, positive-displacement oil pump driven by an electric motor shall be submerged in the oil sump to assure a positive oil supply to the compressor bearings at all times.

b. A low-watt density heater shall maintain the oil temperature at a level that will minimize its affinity for refrigerant. The oil shall be cooled and filtered prior to delivery to the bearings.

c. Provide overpressure relief valve, pressure gauge, sight glass, thermometer, and filter for oil system.

d. Gravity feed reservoir to provide lubrication during coast down in the event of a power failure.

3. Impellers:

a. Impellers shall be fully shrouded, high-strength, aluminum alloy, statically and dynamically balanced, and overspeed tested at a minimum of 115% of operating rpm.

b. Impeller blades shall be curved at the inlet with radial tips to obtain a flat characteristic curve throughout the entire range of operation.

c. The motor/compressor assembly shall be balanced to a maximum vibration amplitude of 1 mil as measured on the motor housing.

4. Automatic capacity reduction equipment consisting of radial blade damper making machine capable of continuous operation at minimum capacity of not more than 15% of specified capacity.

5. Gear box, if required, using interchangeable gears and pinions of the double helical type, with babbitted sleeve bearings; pressure lubrication with pump and cooler.

6. Thermometers or sensors to indicate temperature of bearings or lubricating oil.

7. Open-drive compressors shall have mechanical shaft seal designed to provide long life for refrigerant type and operating pressure.

E. Provide a factory-mounted and wired control cabinet containing an automatic and manual capacity controller, ammeter and volt meters with switches for monitoring each phase, switches to permit manual or automatic operation of oil pump and purge pumps, switch and pilot light to

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operate purge oil separator heater, recycling program timer, gauges to show compressor discharge, evaporator, oil, purge drum pressures, and temperature controllers. Provide panel-mounted meters to indicate total number of compressor starts and elapsed running time. A system pilot light shall be included to indicate control power "On" to the panel. The controls shall use a self-contained, 120V, single-phase, 60 Hz, electrical supply. A numbered terminal strip shall be provided for field interlock wiring. All control panel wires shall also be individually numbered for ease of servicing. The numbering system shall correspond to the manufacturer's circuit diagrams.

F. Provide factory-mounted and wired VSD and disconnect enclosure with main disconnect switch, control power transformer, load limit relay, current transformers, overload protection devices for motor, and safety circuits for compressor.

1. Compressor motor VSD shall be unit-mounted, wired, and tested. The drive shall be air or refrigerant cooled. Refrigerant cooled drives shall be dismounted for rigging and re-mounted by the manufacturer’s authorized personnel.

2. The VFD shall be rated and designed to operate at 460-480V

3. Control power is to be a subfeed downstream of the main disconnect with control transformer and circuit breaker disconnect.

4. The oil pump power supply shall be a subfeed from the main disconnect switch, not a separate source.

G. Piping contractor shall provide the necessary auxiliary piping for oil cooling units, purge condensers, and refrigerant relief vents.

H. A high-efficiency purge system shall be included to operate independent of the unit to automatically remove any non-condensables and water vapors that may be present in the refrigerant system. Non-condensable discharge and refrigerant return shall be automatic functions. Water removal shall be by a manual blow-off valve.

I. Provide oil and refrigerant for each chiller.

2.3 WATER-COOLED CONDENSER

A. The condenser shall be of shell-and-tube design with seamless, integral fin, copper tubes expanded into tube sheets. The condenser shall be made of carbon-steel plate designed, manufactured, tested, and stamped in accordance with Section VIII, Division 01, latest edition of the ASME Boiler and Pressure Vessel Code and its addenda.

B. The condenser shell shall incorporate a refrigerant relief device conforming to

ANSI/ASHRAE 15 Safety Code for Mechanical Refrigeration.

C. The water boxes shall be arranged to permit inspection of the tubes from either end once the connected piping is removed. The water boxes shall be designed for 150 psig (1035 kPa) design working pressure. Vent and drain connections shall be provided on each water box. Provide a hinge for the water box end without piping connections.

D. Tubes and Tube Sheets:

1. Individually replaceable, externally finned, 3/4 or 1-inch (18 or 25 mm) nominal diameter seamless copper tubing shall be used for the heat transfer surface. Tubes shall be

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mechanically expanded into the tube sheets and intermediate supports, providing a leak-free seal.

2. A carbon-steel tube sheet shall be welded to each end of the shell; drilled and reamed to accommodate the tubes.

3. The design shall provide a positive liquid and vapor seal between the refrigerant and water side of the shell after rolling.

4. Intermediate tube support sheet shall be positioned along the length of the shell to avoid contact and relative motion between adjacent tubes.

5. The copper tube wall thickness shall be 0.035 inch (0.89 mm) minimum.

E. Condenser Factory Shell Tests:

1. The refrigerant side of the condenser shell, complete with tubes but without waterbox covers, shall be vacuum leak-tested and pressure leak-tested using a refrigerant trace gas at not less than one and one-half times the design working pressure. Minimum pressure test of 45 psig (310 kPa).

2. The waterside of the shell, with waterbox in place, shall be hydrostatically tested at one and one-half times design working pressure, but not less than 225 psig (1550 kPa).

2.4 INLETS AND OUTLETS

A. The chiller shall have mechanical-groove connections on water boxes. The valve or valves required to divert part of the cooling water to the oil cooler shall be included as part of the manufacturer's assembly.

2.5 SAFETIES, CONTROLS, AND OPERATION

A. Chiller safety controls system shall be provided with the unit (minimum):

1. Low evaporator refrigerant pressure

2. Low evaporator temperature

3. Loss of flow through the evaporator

4. Loss of flow through the condenser

5. High condenser refrigerant pressure

6. Low oil pressure

7. High oil temperature

8. High motor current

9. High motor temperature

10. Compressor surge

11. Starter function fault

12. High pressure drop at oil filter

B. Failure of chiller to start (or chiller shutdown) due to any of the above safety cutouts shall be annunciated by display of appropriate diagnostic code at unit control panel and a single "alarm" output for remote (DDC) monitoring. Anti-recycle timer shall provide for safe interval before chiller restart is allowed.

C. The chiller shall be furnished with a microprocessor-based control system as an integral portion of the chiller control circuitry to provide the following functions:

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1. Ramp loading of the chiller by limiting the rate at which the chiller is allowed to load. The ramp functions shall be field adjustable from several minutes to several hours.

2. Reset the chilled-water supply temperature set point either at the control panel or remotely from an energy management device.

3. Provide automatic chiller shutdown during periods when the load level decreases below the normal operation of the chiller. Upon an increase in load, the chiller shall automatically restart.

4. Provisions for connection to automatically enable the chiller from a remote energy management system (EMS).

5. Reset the demand limit either at the control panel or remotely from an energy management devise.

6. The control panel shall provide alphanumeric display showing all system parameters in the

English language with numeric data in English units.

D. Normal Chiller Operation:

1. When chiller is enabled, factory-supplied microprocessor-based unit control panel modulates the VFD and chiller capacity control vane(s) from minimum to maximum as required to maintain desired leaving chilled water (CHWS) temperature (38 to 58°F (6.7°C

14.4°C), adjustable). Motor current shall be limited to any value from 40 to 100% as set at the unit control panel. Control status "loading," "unloading," or "current limiting" shall be individually indicated.

2. Leaving chilled-water temperature control point shall be capable of being automatically reset by the DDC control system.

3. Chiller slide valve or vane position shall automatically be limited (or reversed) as necessary to prevent tripout of the following safety controls whenever possible:

a. High motor current

b. High condenser (head) pressure

c. Low evaporator temperature

Note: Whenever chiller is operating under one of these overriding limits, the appropriate status code shall be displayed at the unit control panel.

E. Start/Stop: When chilled water flow has been established, the chiller control panel will provide a

"Start" signal to the DDC system to start the condenser water pump. When condenser water flow has been established, the chiller start sequence will progress to completion. The compressor motor shall not start until the chilled water pump and the condenser water pump are operating.

All steps in start sequence shall be displayed by appropriate diagnostic code at unit control panel.

Refer to Division 23 Section "Sequence of Operation for HVAC Controls" and the drawings for additional requirements.

F. The manufacturer shall furnish chilled water and condenser water flow switches compatible with the control circuits in the chiller.

G. The chiller shall call for chilled water and condenser water pump operation through hardwired signals. These signals shall “latch” such that the plant automation system may rely on these signals to maintain pump flow when required by the chiller.

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2.6 ACCESSORIES

A. Acoustical Shroud: Provide an acoustical shroud for the compressor/motor section as required to limit the radiated noise from the chiller. The noise level shall not exceed 85 dba when measured

5 feet from the machine as the chiller is operating from 15% to 100% of full load.

2.7 SOURCE QUALITY CONTROL

A. Factory Performance Test (For Each Unit):

1. A chiller performance test shall be conducted at the factory in accordance with ARI

Standard 550/590.

2. The chillers shall be run-tested under full load conditions to check performance (tons and kW), vibration, operating controls, and safety cutouts. The factory shall provide to the contracting officer a certified test report to confirm that the chillers perform as specified before final payments are made. The chillers will also be tested at the alternate conditions specified.

3. The contracting officer shall be notified 21 days in advance of each test to review the installation and witness the factory performance test. If the contracting officer or other members of the design team desires to witness the performance test, all travel expenses will not be the contractor’s or manufacturer’s responsibility .

4. The equipment will be accepted if the test procedures and results are in conformance with

ARI Standard 550/5908. If the equipment fails to perform within allowable tolerances, the manufacturer will be allowed to make necessary revisions to his equipment and a retest as required. In the event that these revisions do not achieve submitted performance, the following penalties will be imposed on full load performance:

a. Capacity Test: For each ton below the allowable full load tolerance set forth in ARI

Standard 550/590 of the design capacity, a capacity penalty (C.P.) of $1,000 per ton will be assessed to the manufacturer or deducted from the contract price.

b. Power Consumption Test: The power consumption penalty shall be based on the allowable tolerances set forth in ARI Standard 550/590. The power consumption penalty (P.C.P.) will be calculated based on the following formula.

Allowable Tolerance = 10.5 − (0.07 x % full load)

1,500 chilled water ∆T °F x% full load

(Note: ARI treats the percentage divisor as a numeric value rather than a decimal fraction, i.e., 75% = 75, rather than 0.75.)

C.P. = {Design Capacity x (100% -Allowable Tolerance) – Measured

Capacity} x $500/Ton ($1,757/kW)

P.C.P. = {Measured kW/ton - (Design kW/ton x (1 + Allowable

Tolerance)} x Measured kW x $1,000/kW

*Allowable kW/T = (1 + Allowable Tolerance) x design kW/T

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c. Total Performance Penalty: The total performance penalty will be the Capacity

Penalty plus the Power Consumption Penalty.

d. Any required retesting shall be at the expense of the manufacturer.

PART 3 - EXECUTION

3.1 EXAMINATION

A. Examine areas to receive chillers for compliance with requirements for installation tolerances and other conditions affecting chiller performance. Proceed with installation only after unsatisfactory conditions have been corrected.

B. Final chiller locations indicated on drawings are approximate. Determine exact locations before roughing-in piping and electrical connections.

3.2 INSTALLATION

A. Installation of the chiller shall be in accordance with the drawings and specifications and the manufacturer's recommendations.

B. Install chillers level and plumb, and anchor to base.

C. Maintain manufacturer's recommended clearances for service and maintenance.

D. Provide insulation to the evaporator, suction lines, and other surfaces where condensation might occur where not factory insulated. See 23 0700 Mechanical Insulation.

E. Install electrical components, devices, and accessories furnished loose by manufacturer, including remote flow switches and remote chiller control panel.

F. Piping installation requirements are specified in other Division 23 Sections. Drawings indicate general arrangement of piping, fittings, and specialties. The following are specific connection requirements:

1. Install piping adjacent to machine to allow service and maintenance.

2. Extend safety-relief valves or rupture-disc discharge piping from chiller and purge condenser receiver to exterior of building. Provide unions and flex connectors in piping for each relief valve.

3. Install piping such that no forces are exerted on chiller nozzles. Align flexible connectors in accordance with manufacturer's recommendations and alignment tolerances.

3.3 START-UP SERVICE

A. Engage a factory-authorized service representative to perform start-up service.

B. Inspect field-assembled components, equipment installation, and piping and electrical connections for proper assemblies, installations, and connections.

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C. Complete installation and start-up checks according to manufacturer's written instructions and perform the following:

1. Verify that refrigerant charge is sufficient and chiller has been leak tested.

2. Verify that pumps are installed and functional.

3. Verify that thermometers and gages are installed.

4. Operate water chiller for run-in period according to manufacturer's written instructions.

5. Check bearing lubrication and oil levels.

6. Verify that refrigerant pressure relief is properly vented to the outside.

7. Verify proper motor rotation.

8. Verify static and dynamic deflection of vibration isolators, including deflection during water chiller start-up and shutdown.

9. Verify and record performance of chilled and condenser water flow and low-temperature interlocks.

10. Verify and record performance of chiller protection devices.

11. Test and adjust controls and safeties. Replace damaged or malfunctioning controls and equipment.

D. Prepare a written start-up report that records results of tests and inspections.

3.4 DEMONSTRATION

A. Engage a factory-authorized service representative to train Owner's maintenance personnel to adjust, operate, and maintain water chillers. Video record the training sessions.

3.5 CLEANING

A. After completing installation, including outlet fittings and devices, inspect unit components.

Remove paint splatters and other spots, dirt, and debris. Repair damaged finish to match original finish.

END OF SECTION 23 64 13