Heat Recovery Chillers

MD ANDERSON Project No. XX-XXXX MD ANDERSON PROJECT NAME A/E Name Issue Description A/E Project No. Month, 00, 0000

SECTION 23 64 20 – HEAT RECOVERY CHILLERS

PART 1 - GENERAL

0.1 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General Conditions and Division 01 Specification Sections, apply to this Section.

B. Specifications throughout all Divisions of the Project Manual are directly applicable to this Section, and this Section is directly applicable to them.

0.2 SUMMARY

A. Perform all Work required to provide and install water cooled Heat Recovery Chiller (HRC) with the cooling in tons and heating capacity as scheduled on the Drawings with the required trim components, including all related appurtenances to make a complete, functioning and operational system that will supply chilled and hot water for HVAC use. If more than one unit or module is submitted, each must be able to meet the design evaporator and condenser leaving water temperature on its own. In addition, spare fuses for each chiller are to be provided for electrical and electronic components where fuses are required to maintain chiller operation. On assembled modular units, each unit shall be have separate electrical power connections from an electrical panel with separate wiring and conduit, the use of bus bar power connections between modules are not acceptable.

0.3 REFERENCE STANDARDS

A. The latest published edition of a reference shall be applicable to this Project unless identified by a specific edition date.

B. All reference amendments adopted prior to the effective date of this Contract shall be applicable to this Project.

C. All materials, installation and workmanship shall comply with the applicable requirements and standards addressed within the following references:

1. Conform to ANSI/ASME Boilers and Pressure Vessels Code Section VIII, Division 1 for design and fabrication of pressure vessels for manufacture of tubular heat exchangers and heat exchanger shells as applicable.

2. ARI Standard 550/590 - Standard for Water Chilling Packages using the Vapor Compression Cycle (not applicable to modular type HRC’s).

3. AHRI certification applies to modular type HRC’s using R-410a refrigerant.

4. UL 1995 Code for Heating and Cooling Equipment (applicable to modular type HRC’s).

5. ANSI/ASHRAE Standard 15 - Safety Code for Mechanical Refrigeration.

0.4 QUALITY ASSURANCE

A. Factory pressure testing of the chiller condenser and evaporator sections shall be in strict conformance with all applicable sections of the ASME code and shall bear the standard ASME symbol or stamped for smaller capacity modular type HRC units.

The University of Texas HEAT RECOVERY CHILLERS MD Anderson Cancer Center 23 64 20 MS070213 1 OF 11 MD ANDERSON Project No. XX-XXXX MD ANDERSON PROJECT NAME A/E Name Issue Description A/E Project No. Month, 00, 0000

B. All equipment or components of this Section shall meet or exceed the requirements and quality of the items herein specified and as denoted on the Drawings.

C. Modular type HRC’s shall be factory run tested prior to shipment on an AHRI certified or 3rd party verified test stand. Capacity rating shall be in accordance with AHRI certification.

D. Single Point Power: HRC Modular Stack units shall be equipped with a pre-engineered genuine buss bar electrical system for single point power. Where the equipment size exceeds the amp rating of the buss bar, multiple power connections may be applied. Pre- engineered system shall also incorporate individual module isolation circuit breakers for full redundancy and ability of a module to be taken off-line for repair while the rest of the modules continue to operate. Individual power feeds to each module is not acceptable.

E. Where applicable, the manufacturer shall be listed by Underwriter's Laboratories as a manufacturer of packaged pumping systems.

F. Comply with applicable NEC requirements for electrical and control wiring.

G. Design and construction of chiller electrical components shall meet UL 465 requirements and shall have labels appropriately affixed.

0.5 SUBMITTALS

A. Product Data:

1. Shop drawings showing the installation of the HRC, details of components, attachments, flow meters, sensors, isolation and control valves, strainers and other construction elements that included the following drawings:

a. System electrical line and schematic drawings showing factory and field power and control wiring and include the compressor staging control sequence.

b. System piping line schematic diagrams showing factory and field piping connections between the chiller and Owner’s ancillary equipment.

2. Dimensioned shop drawings submittals indicating assembled equipment, physical dimensions, weight (shipping and operating), and lifting loads, required clearances for operation maintenance, and location and size of electrical wire and conduit connections, electrical and control panel drawings.

3. Panel drawings panels building automated control wire connections, furnished accessories and electrical characteristics. Equipment independently tested product showing the “Intertek seal mark” shall bearing the ETL Listed mark with the "us" identifier at the 4 o'clock position which means the product was tested and deemed compliant to U.S. product safety standards. The supplier shall provide a documentation list with the date of the applicable standards and codes independently performed by the Intertek.

4. Drawings should include the type and quantity of refrigerant, cooling and heating capacities at the scheduled operating conditions listed on the, condenser and evaporator pressure losses, at maximum and minimum fluid flow and temperature conditions. Electrical power data and requirements and kW/ton at part load values.

5. Provide comprehensive performance data of the HRC from 100 percent to 25 percent capacity in 25 percent increments maintaining constant design condenser water and design chilled water design temperature differentials while reducing hot and chilled water flow rates.

6. Provide the necessary acoustic panel treatment to the HRC as required to meet an average sound pressure level of 87 (dBa) at a distance of 1 meter. The sound test shall be in accordance with ANSI / AHRI Standard 575. Use Durodyne insulation adhesive or equivalent to fasten insulation on HRC module panels. Install handles on each module’s panels to facilitate ease of removal and installation.

B. Record Documents:

1. Submit manufacturer’s installation instructions.

2. Submit pressure test reports of vessel shell and tube bundle pressure tests.

C. Operation and Maintenance Data:

1. At Substantial Completion, submit operation and maintenance data that includes start-up and shutdown instructions, assembly Drawings, and spare parts lists.

0.6 DELIVERY, STORAGE AND HANDLING

A. Deliver, store, protect and handle products to the Project Site under provisions of Division 01 and Division 20.

B. Protect internals from entry of foreign material by temporary caps on flanged openings.

0.7 WARRANTY

A. Provide breakout price during bid process for the following:

1. Base bid for five-year factory warranty.

a. Coverage shall include complete chiller package as manufactured and delivered to the Project Site including materials and labor for the first year (factory warranty), and material only for the remaining four years.

2. Warranty period commences upon Owners sign-off of project Substantial Completion.

PART 2 - PRODUCTS

0.1 GENERAL

A. All materials shall meet or exceed all applicable referenced standards, federal, state and local requirements, and conform to codes and ordinances of authorities having jurisdiction.

0.2 MANUFACTURERS

A. Multistack

B. Trane

C. McQuay

D. ClimaCool

E. Tandem

0.3 REFRIGERANTS

A. Base bid for the proposed chiller using refrigerant: R-410a.

B. Provide an alternate bid for the proposed chiller using refrigerant: R-134a.

C. Refrigerants acceptable for use are: R410a, R-407c or R-134a.

0.4 COMPRESSORS:

A. Hermetic scroll type.

B. Scroll Compressor assemblies or modules: Each assembly or module shall contain two hermetic scroll compressors independently circuited and with internal spring isolation mounted to the module with rubber-in-shear isolators. Each system also includes high discharge pressure and low suction pressure manual reset safety cut-outs. The view of each compressor’s oil level sight glass shall be unobstructed by other module components for inspection.

C. When there is more than one chiller module, each module shall be labeled as (Module #1, 2…)

D. When there is more than a single compressor on an individual module, the compressors shall be identified (labeled) as A and B on each module.

E. Hermetic Drive Motors:

1. Liquid refrigerant cooled with internal thermal overload protection devices embedded in the winding of each phase.

2. Motors shall be compatible with the starting method specified hereinafter.

0.5 CONDENSER AND EVAPORATOR:

A. HRC capacity selection shall be based on a water side fouling factor of 0.00025 in the evaporator tubes and 0.00025 in the condenser tubes. Evaporator and condenser water pressure drops shall not exceed those scheduled on the Drawings. HRC shall be rated in accordance with the latest edition of ARI Standard 550 pressure test and certified per ASME, and also meet ASHRAE 15 Safety Code.

B. Heat Exchangers :

1. Shell and Tube type design:

a. Welded steel shells and copper tubes with integral fns, rolled or silver brazed to tube sheets. Tube supports to be at maximum of 4'-0”.

b. The condenser shall use refrigerant baffles in the to distribute entering gases and to concentrate non-condensable gases.

c. The evaporator shall be designed such that refrigerant liquid is to be distributed evenly across the evaporator and that potential of having liquid refrigerant carryover into the compressor is eliminated.

d. Design waterside of evaporators and condensers for 150 PSI working pressure and test not less than 1.5 times maximum working pressure.

e. Test refrigerant side not less than 1.5 times maximum working pressure and not less than 45 PSI.

f. Provide taps in water boxes for vents, drains, and control connections.

g. Provide condenser and evaporator tubes with minimum tube wall thickness of 0.035 inches.

h. Evaporator and condenser tubes may be internally enhanced to improve heat transfer efficiency.

i. HRC Modular Unit capacity selection shall be based condenser and evaporator fouling factor, and/or water pressure drops shall not exceed those scheduled on the Drawings.

2. Plate and Frame type design:

a. Brazed plate heat exchangers constructed of AISI 316 stainless steel; designed and stamped in accordance with the applicable codes, for a working pressure of 650 psig for the evaporator and the condenser.

b. The evaporator shall be designed to distribute refrigerant gas evenly through the distribution header and across the evaporator plate to eliminate liquid refrigerant carryover into the hermetic compressor casing.

c. HRC Modular Unit capacity selection shall be based condenser and evaporator fouling factor, and/or water pressure drops shall not exceed those scheduled on the Drawings. HRC shall be pressure tested in accordance with applicable UL1995, and also meet ASHRAE 15 Safety Code.

d. Chillers shall have total access design with isolation valves between the heat exchangers and the integral headers for heat exchanger isolation without the requirement to shut down the chiller allowing for total access to all serviceable components.

C. Provide refrigerant over-pressurization safety relief. Re-seating refrigerant pressure relief valves. If the mass quantity of refrigerant is large enough to the point where relief piping is required per ASHRAE 15 Safety Code, refrigerant rupture disk are acceptable relief devices

D. Water Pipe Connections:

1. Reference the equipment schedule for evaporator (cooler and condenser pipe connections.

2. There are two (2) types of water connection configurations:

a. Victaulic to flange adaptors for grooved pipe.

b. Welded steel flanges.

[NOTE TO ENGINEER IF IT MAKES NO DIFFERENCE, THEN LEAVE THIS SPECIFICATION AS WRITTEN. IF IT MAKES A DIFFERENCE, THEN THE SPECIFICATION NEEDS TO BE MORE SPECIFIC WITH RESPECT TO HAVING VICTAULIC CONNECTIONS.]

c. Welded steel arranged to permit inspection of tubes from either end without disturbing water chamber of connecting water piping.

d. Each inlet water header shall incorporate a built in 30-mesh (minimum) in-line strainer system to prevent heat exchanger fouling and accommodate 100% flow filtration with a minimum surface area of 475 sq inches per module.

E. Chiller shall be designed to operate with both variable condenser and evaporator water flow. Chiller shall include valves, controls, and accessories to allow for the chiller to operate efficiently in a variable primary flow system. Valve shall modulate via a motorized actuator for leaving water temperature control, chiller minimum flow bypass, chiller no load bypass, or head pressure control.

0.6 CONTROLS:

A. The HRC master controller and module controller shall have administrative security password locks.

B. The BAS point name designation shall be coordinated with the client and the controls contractor.

C. Provide stand-alone remote mounted and powered direct digital master controller for each HRC The master controller shall be microprocessor-based and BACnet compatible and factory testing of required control components for reliable equipment operation. The controller or control system shall monitor entering and leaving hot and/or chilled water temperatures to determine system load and select the number of compressor circuits or if equipped with a VFD vary the compressor speed, required to maintain operation to existing building conditions.

D. Chiller shall be capable of operating with any chiller module out of service. The remote mounted master controller shall powered such that it is operational even if power is disconnected from any single module.

E. The HRC controller or control system shall provide monitoring and record fault conditions. The panel shall be a complete system for stand-alone chiller control and include controls to safely and efficiently operate the chiller. The panel shall be equipped with a compatible building automation system interface.

F. The Fail to Run Mode (FRM) automatically transfers chiller operation from the master controller over to each chiller module board if the master controller fails.

G. The HRC controller shall be capable of receiving and utilizing CHWS temperature setpoint (adj.) and HWS temperature setpoint (adj.) from the building automation system.

H. Provide a control cabinet containing the following operating and safety controls:

1. Provide Master controller for:

a. Automatic shutdown and restart

b. Adjustable leaving hot (condenser) water setpoint.

c. Connections to remote energy management system.

d. Connects to slave controllers and permit slave controllers to function on loss of connectivity.

e. Controls the unit(s) heating capacity from minimum to maximum as required by building load.

f. Responds to entering water temperature to maintain efficiency at part load conditions.

g. Lead / lag operation of (applicable) HRC modules or compressors.

2. Provide a power phase Monitor for:

a. Automatic shutdown on detection low of voltage.

b. Automatic shutdown on detection of a power phase rotation.

c. Automatic shutdown the loss of a power phase.

d. Automatic shutdown on detection of a power phase imbalance.

3. Provide safeties to for:

a. Automatic shutdown loss of chilled water flow through evaporator.

b. Automatic shutdown loss of hot water flow through the condenser.

c. Automatic shutdown low evaporator refrigerant pressure cutout with manual reset.

d. Automatic shutdown high condenser refrigerant pressure cutout with manual reset

e. Automatic shutdown high compressor motor temperature cutout.

f. Automatic shutdown low suction gas temperature..

g. Automatic shutdown form low leaving evaporator water temperature.

0.7 SAFETIES, CONTROLS AND OPERATION

A. Dedicated Heat Recovery Chiller safety controls system shall be provided with the unit (minimum) as follows:

1. Low evaporator refrigerant pressure

2. Loss of flow through the evaporator

3. Loss of flow through the condenser

4. High condenser refrigerant pressure

5. High compressor motor temperature

6. Low suction gas temperature

7. Low leaving evaporator water temperature

B. Failure of Dedicated Heat Recovery Chiller to start or Dedicated Heat Recovery Chiller shutdown due to any of the above safety cutouts shall be enunciated by display of the appropriate diagnostic description at the unit control panel. This annunciation will be in plain English. Alphanumeric codes shall be unacceptable.

C. The Dedicated Heat Recovery Chiller shall be furnished with a Master Controller as an integral portion of the Dedicated Heat Recovery Chiller control circuitry to provide the following functions:

1. Provide automatic Dedicated Heat Recovery Chiller shutdown during periods when the load level decreases below the normal operating requirements of the Dedicated Heat Recovery Chiller. Upon an increase in load, the Dedicated Heat Recovery Chiller shall automatically restart.

2. Provisions for connection to automatically enable the Dedicated Heat Recovery Chiller from a remote energy management system.

3. The control panel shall provide alphanumeric display showing all system parameters in the English language with numeric data in English units.

4. Each module shall contain a slave controller that will allow any module to run in the event of a master controller failure or loss of communication with the master controller via an on/off/manual toggle switch.

5. Low voltage panels shall use a draw latch to secure low voltage door panels.

D. Normal Dedicated Heat Recovery Chiller Operation

1. When Dedicated Heat Recovery Chiller is enabled, the factory supplied Master Controller modulates the Dedicated Heat Recovery Chiller capacity from minimum to maximum as required by building load.

2. The Dedicated Heat Recovery Chiller control system shall respond to Entering Water Temperature and will have an integral reset based on entering water temperature to provide for efficient operation at part-load conditions.

E. Power Phase Monitor

1. Provide a Power Phase Monitor on the incoming power supply to the Dedicated Heat Recovery Chiller. This device shall prevent the Dedicated Heat Recovery Chiller from operating during periods when the incoming power is unsuitable for proper operation.

2. The Power Phase Monitor shall provide protection against the following conditions:

a. Low Voltage (Brown-Out)

b. Phase Rotation

c. Loss of Phase

d. Phase Imbalance

0.8 STARTER:

[NOTE TO ENGINEER IF THE SPECIFICATION IS CURRENTLY WRITTEN FOR PROVIDING A CHILLER THAT OPERATES AT 480V / 30PH / 60HZ POWER. IF THE CHILLER USES 4160 VOLTS AS A POWER SOURCE,

THEN THE STAR DELTA STARTER REFERRED TO IN THE SPECIFICATION IS NOT APPLICABLE. THE 4160 VOLT MOTOR MUST BE CONNECTED TO A PRIMARY REACTOR OR AUTOTRANSFORMER STARTER.] A. Provide where scheduled on Drawings.

B. Automatic reduced voltage type, star delta closed transition unit mounted.

C. Accessories / Appearances:

1. Solid-state single-phase and voltage imbalanced protection.

2. 120-volt control transformer.

3. Main power non-fused disconnects.

4. Ammeter in cover, red lined at compressor full load amps.

0.9 CAPACITY CONTROL BASED ON DEMAND LOAD:

A. Capacity control of the HRC can be achieved by any one of these means as follows:

1. Staging operation of single speed compressors.

2. Using variable speed driven compressor(s).

3. Varying gas flow rate using mechanical modulation of the compressor driven by a single speed motor

B. Creating a stalled gas flow condition within the compressor impeller or the use of a hot gas bypass valve is not acceptable.

C. Compressor Staging:

1. Controllers for staging compressors shall be programmable by adjusting established setpoints for start and stop operation of compressors to properly follow demand load.

2. The controller shall also be able to automatically change lead lag compressor operation.

3. Staging of compressor operation shall be monitor and able to prevent overheating of compressor motor stator wiring.

D. The following features shall be provided:

1. UL listed ground fault protection.

2. Overvoltage and under voltage protection.

3. 3-phase sensing motor.

4. Over current protection.

5. Single phase protection

6. Insensitive to phase rotation.

7. Over temperature protection.

8. Self-diagnostic service parameters.

[NOTE TO ENGINEER IF THE QUANTITY (LBS.) OF REFRIGERANT RELEASED PER VESSEL DOES NOT EXCEED ASHRAE 15 THEN A MONITOR IS NOT REQUIRED.] 0.10 REFRIGERANT MONITOR:

A. Provide calibrated, refrigerant monitor for specific refrigerant used, capable of detecting concentrations of 10 ppm for low level detection.

B. Provide monitor with audible and visual alarms that activate at a valve corresponding to the TL V of the refrigerants in use. The alarm system shall annunciate visual and audible alarms inside the machinery room and outside each entrance to the room.

1. Monitor shall have the capability of detecting, alarming and controlling from 0-50 ppm. Digital display accuracy shall be within one (1) ppm.

2. Monitor shall require only minimum maintenance.

a. Recalibrate no more than once every five (5) years.

b. Re-zeroing no more than once every week.

3. Monitor shall be capable of operation in ambient temperatures from 40 to 105 degrees F.

4. Have the following output capabilities.

a. Two (2) analog setpoints and three (3) binary with individual closure setpoints.

b. Connect one alarm contact to the BAS to indicate alarm condition into the BAS system.

c. Remaining alarm contacts shall initiate closure of magnetic motor starters to energize the refrigerant purge supply fan and exhaust fan.

C. Approved Monitor Manufacturers: Bacharach, General Analysis Corporation, Yokogawa, and MSA.

PART 3 - EXECUTION

0.1 INSTALLATION:

A. Installation shall meet or exceed all applicable federal, state and local requirements, referenced standards and conform to codes and ordinances of authorities having jurisdiction. All installation of HRC shall be in accordance with manufacturer’s published recommendations.

B. Installation of HRC shall comply with requirements of ANSI/ ASHRAE 15-2001.

C. Prior to connecting the HRC to new hot water and chilled water piping, the piping shall be flushed with a detergent and hot water (110-130° F) mixture to remove previously accumulated dirt and other organics. Hoses, clamps, pump and strainers or pleated filter are too be used during the flushing operation. A # 40 mesh size (max.) Y-strainers or an alternate equivalent acceptable to the HRC manufacturer shall be placed in the system piping and examined periodically as necessary to remove collected residue. The Y-strainers with # 40 mesh size shall be located downstream on the discharge side of the HRC’s chilled water and hot water pumps The flushing process shall take no less than 6 hours or until the strainers when examined after each flushing is clean.

D. If old existing piping systems show heavy encrustation of inorganic materials inside the piping consult a water treatment specialist for proper passivation and/or removal of these contaminants. These piping systems shall be flushed for a minimum of 24 hours and may take as longer until the filters are clean. Detergent and acid concentrations shall be used in strict accordance with the respective chemical manufacturer’s instructions. After flushing with the detergent and/or dilute acid concentrations the system loop shall be purged with clean water for at least one hour to ensure that all residual cleaning chemicals have been flushed out.

E. Install Owner’s piping at condenser and evaporator to avoid interfering with tube cleaning or repair.

F. Install Owner’s piping to minimize weight and length of piping sections, which needs to be removed to perform maintenance on the HRC.

G. Insulate HRC evaporator and other surfaces subject to sweating in accordance with Section 20 07 16.

H. Install HRC(s) on isolation pads as specified in Section 20 05 48.

I. Refer to division 26 Sections for wires, cables, and the manufacturer’s electric installation instructions.

J. Independent electrical feeds to modules are needed for maintenance purposes and in the event of a master controller failure.

K. Provide a competent, factory trained representative to completely supervise the installation and to perform all on-site run-in tests.

0.2 TESTING

A. HRC performance must include an ARI approved selection method. Verification of date and version of computer program selection of catalog is available to the Engineer.

END OF SECTION 23 64 20

The University of Texas HEAT RECOVERY CHILLERS MD Anderson Cancer Center 23 64 20 MS070213 11 OF 11