STANDARD SPECIFICATION FOR AIR CONDITIONING SYSTEM HINDUSTAN PETROLEUM CORPORATION LTD. VISAKH REFINERY DHT PROJECT

Transcription

1 STANDARD AIR CONDITIONING SYSTEM HINDUSTAN PETROLEUM CORPORATION LTD. VISAKH REFINERY DHT PROJECT JOB NO. : 6261 DOCUMENT NO. : 6261-AA-301 TEIL SPECIFICATION NO. AA For Bid Enquiry AMR / ARN SMW SVW Rev no. issue date Description Prepared by Checked by Approved by TOYO ENGINEERING INDIA LIMITED MUMBAI, INDIA

2 DOC.No AA -301 DHT PROJECT Page 1 of 13 CONTENTS 1.0 GENERAL TECHNICAL REQUIRMENTS Controls and Instruments CODES AND STANDARDS Performance Testing and Guarantees 11 APPENDIX 1 INSULATION MATERIAL AND THICKNESS 12

3 DOC.No AA -301 DHT PROJECT Page 2 of GENERAL Complete air conditioning system for areas specified in requisition documents shall be provided as per the design requirements set forth in the following clauses. CONTRACTOR shall design equipment for Air-conditioning in accordance with codes standards and as per specifications. 2.0 TECHNICAL REQUIRMENTS 2.1) Duty The plant shall be suitable for maintaining inside design conditions all the year round. All equipment shall be suitable for continuous operation for 8000 hrs per year. 2.2) Refrigerant The refrigerant to be used shall be environmental friendly unless otherwise specified or approved by the Owner. 2.3) Reciprocating Refrigerant Compressor and Scroll Refrigerant Compressor a. Compressor shall have proven track record. b. Electric driver rating (exclusive of service factor) shall be minimum 110% of the maximum power required (including transmission losses) at operating conditions. 2.4) Screw Refrigerant Compressor a. The compressor shall have proven track record. b The compressor shall be equipped with automatic unloaded starting arrangement through suction pressure sensor. c. Oil cooler shall be refrigerant/water cooled/refrigerant injection type. Oil separator shall be capable of 50 ppm oil separation as a minimum. If required suitable secondary filter or coalescer may be provided. Duplex type oil filters are to be provided for uninterrupted service in the lube oil circuit. SS material shall be used for complete oil piping. d. Lubrication and oil cooling system shall include oil reservoir or sump, oil separator, oil heater, oil pump, pump inlet screen, oil cooler, oil filter, pressure regulator and distribution piping and control valves.

4 DOC.No AA -301 DHT PROJECT Page 3 of 13 e. Electric driver rating (exclusive of service factor) shall be minimum 110% of the maximum power required (including transmission losses) at operating conditions. 2.5) Condenser a) The tubes shall not be less than 12.5 mm diameter and shall be adequately supported to prevent tube vibration. b) Condensers for 160 TR and above rated AC plants shall have water boxes & covers so that each tube sheet cab be exposed without disturbing the piping connections. 2.6) Air Handling Unit Fan 2.7) Drive 2.8) Filters a) The fans shall be forward curve bladed centrifugal type. The number of fans per unit shall be as per standard of the manufacturer. b) The impeller and the scroll casing of the fans shall be made of steel and protected with suitable painting. c) The fan shaft shall be of carbon steel. Bearing shall be heavy duty self aligning type. d) The fans shall be dynamically balanced. e) The motor shall be mounted outside the AHU. The motor shall be adequately designed to prevent overload. a) Centrifugal fans shall be equipped with V-belt drive and belt tensioning arrangement. b) All belts shall be sized for 150% rated horse power. All belt drive shall be equipped with removable guards to avoid accidents hazards. c) There shall be a minimum of two belts per drive. a) Fine filters shall be provided downstream of AHU filters. Filters shall be capable of filtering dust up to 5 microns particle with an efficiency of 99%. b) Fine filters shall be selected for a pressure drop of 6.5 mm WG in clean conditions. c) Inclined tube manometer with tubing shall be provided for indication of pressure drop across fine filters.

5 DOC.No AA -301 DHT PROJECT Page 4 of 13 d) Fresh air filters of panel type shall be provided in fresh air intake point. These shall be similar to AHU filters. Velocity of air through filters shall be max upto 2.5 m/sec. e) In case of clean room application HEPA filters shall be provided as specified in datasheet. f) If called out in design basis/ data sheet, chemical filter shall be provided as a fresh air filter. g) Chemical Filter unit shall be skid mounted suitable for horizontal installation. h) Filter Packs suitable for removal of specified gases and particulate matter shall be housed in an adequately rigid & reinforced galvanised sheet metal enclosure with flanged inlet & outlet connections, inspection doors. All inspection doors shall be provided only on one side of chemical filter. i) The chemical filter unit will have panel filters at inlet & outlet capable of removing dust particles of 10 micron with 90% efficiency and of 1+ micron with minimum 90% efficiency respectively. j) The chemical Filter unit shall be suitable for outdoor installation and continuous operation. Rain louvre & bird screen at air inlet shall be provided. Metallurgy shall be suitable for specified site condition and shall be accordingly protected and painted. Chemical filter unit mounted outside shall be suitably protected against rain. FRP canopy shall be Provided. k) The chemical Filter unit shall be provided with gauge assembly for measurement of differential pressure. 2.9) Cooling Coils a) The cooling coils for either DX or chilled water shall consist of seamless copper tubes with aluminum fins. Minimum 4 Fins/CM. Each AHU shall be provided preferably with only one number cooling coil. b) The cooling coil for chilled water plant shall be equipped with manually operated low regulating valve to control the chilled water flow. This cooling coil shall be designed for chilled water/air duty. c) The cooling coil for DX and chilled water plant shall be equipped with thermostatic expansion valve and liquid line solenoid valve to control the refrigerant flow. The cooling coils for DX plant shall be designed for refrigerant/air duty. d) Counter-flow process of heat transfer shall be considered in the design requirement.

6 DOC.No AA -301 DHT PROJECT Page 5 of 13 e) The fouling factor of hr. ft 2 - o F/BTU ( hr -m² o C/Kcal) shall be taken in the design of the cooling coil. f) Even number of rows like 2,4,6 and 8 etc shall be selected for any particular coils to facilitate connection of water/refrigerant only on one side of the unit. g) Fin design shall be chosen for the duty to be performed with special attention to the possibility of lint accumulation. h) Velocity of air across the coils shall be limited to 2.5 m/sec. 2.10) Casing a) The casing shall be constructed of minimum 18 gauge MS/GI removable sheet panel with proper reinforcement. The casing shall be suitably painted to prevent corrosion in case of M.S. sheet metal construction. Base frames shall be supplied for floor mounted type units b) Drain pans may be manufactured of double bottom type or otherwise sufficient insulation shall be pasted with bituminous compound to avoid condensation on the outside surface. The supplier shall guarantee against condensation of water on the outside of the unit. c) Panels of the casing shall be fitted reasonably air tight with suitable gaskets with cams or similar fastenings for easy opening. Necessary arrangement shall be provided on the casing for measuring temperature and pressure in a cooling coil. d) Waterproof, vermin proof sound and heat insulation shall be provided on the inside of the casing. The thickness of insulation at the coil section after the cooling coil shall be adequate to arrest condensation of moisture on the outside surface of the units. The insulation shall be securely fixed so that the same does not fail out during operation of the units. Fibrous insulation without protective covering should not be used inside the casing. e) The drain pans shall be of 16 gauge M.S. They shall be hot dip galvanized after fabrication or otherwise treated to resist corrosion. The drain pan shall be extended to catch any free moisture carried over from the coils. The drain connection shall be readily accessible for cleaning & shall be generously sized 2.11) Fire Damper a) Fire dampers shall be installed in supply air and return air path. b) These shall conform to UL-555 for 1.5 hour fire rating. The fire dampers shall be provided with limit switches for indication of open/close position of dampers.

7 DOC.No AA -301 DHT PROJECT Page 6 of 13 c) Fire dampers shall be electric motorised type. d) Necessary interlocking of Fire damper s with plant F & G system, shall be provided to shut down the air conditioning system in case of presence of hazardous gas or fire. e) Signal from purchaser s fire & gas panel shall be made available at vendor s Local Control Panel, in the form of potential free contact. The wiring from this contact upto motor actuator shall be done by vendor. 2.12) Heating Unit a) Heating shall be preheating and/or reheating as per psychometric process requirement. b) Heating shall be electric/hot water/steam. c) Electric strip heaters, if provided shall be complete with heating thermostat/humidistat safety thermostats and contactors. Hot water/steam coils shall be complete with control valve. Humidistat/thermostat etc. 2.13) Humidifier Unit a. Humidification shall be provided as per psychometric process requirement. Pan humidifier shall be complete with immersion type electric heaters actuated by humidistat, water float valve, stop valve in water make up line, level switch interlocked with heaters. b) Drain pan/water collecting trough of water spray humidifier shall be of 16 gauge GSS and thermally insulated. c) The humidifier shall be sized to deliver 110% of capacity required. 2.14) Refrigerant Piping The refrigerant piping shall be of copper and the cooling coils shall be of heavy gauge copper tube with aluminium fins. Rows shall be staggered in the direction of airflow. Refrigerant piping shall be complete with thermostatic expansion valve, liquid-line strainer. 2.15) Air Distribution, Ducting Diffusers / Grilles a) All ducts shall be made of galvanised steel sheets conforming to grade 200 of IS-277 or equivalent. b) Ducts shall be designed, fabricated and flanged as per IS-655 for static pressure up to 65 mm WG. Incase, the static pressure is more than 65mm WG, SMACNA code, shall be followed for design and fabrication of duct

8 DOC.No AA -301 DHT PROJECT Page 7 of 13 c) Duct shall be machine made to improve the quality of ducts, d) Spacing of flange joints shall be at 3 meters maximum. e) Duct supporting hangers shall be used at a spacing not exceeding 3 meters. Hangers shall be supported from anchor fasteners. f) All flanges shall be joined by using galvanized bolts, nuts & washer at about 125mm center to center. Size of the nut bolt shall be M6 for ducts having larger side up to 1000 and M 10 for ducts having larger side greater than 1000 mm. g) Angle iron flanges shall be provided for ducts by using rivets at about 100mm center to center. Ducts shall be lapped 6mm across the flanges. h) All flange joints shall have 6mm thk Neoprene packing as gasket stack to the flanges with adhesive (viz., resins like araldite or equivalent). i) All the duct shall be made air tight with the help of sealant. j) Water drain points (Condensation) Shall be provided at Uniform intervals. k) Duct work shall be provided with following accessories. - Turning Guide Vanes. - Extractor with operating lever. - Splitter Damper with control rod & locking device. - Volume control damper (opposed bladed type with 16 gauge 250 mm wide blades and 14 gauge casing of GSS). - Fire resistant flexible connection between duct chute and diffuser (if required). Access doors for heaters, fire dampers and filters. l) Supply air diffusers or grilles shall be provided as required fitted with sponge foam tape. Volume control damper shall be provided with each supply air diffuser/grille. Volume control damper shall be key operated from the front of diffuser/grille. Supply air grilles shall be provided with vertical & horizontal adjustable louvers. m) Diffusers/grilles shall be of Anodised Aluminiurn construction. n) Diffusers/grilles shall not be supported from False Ceiling. 2.16) Insulation The surfaces to be insulated shall be thoroughly cleaned and allowed to dry. Pressure/hydraulic test, if any, shall be carried out before insulation. The application, insulation material and recommended thickness are given in Appendix 1. a) Hot Insulation

9 DOC.No AA -301 DHT PROJECT Page 8 of 13 Bare surfaces of pipe/equipment shall be provided with one coat of 20 micron min. (Dry film thickness) heat resistant aluminium paint up to 125ºC, the surface shall be wrapped with 0.l9mm thick aluminum foil before application of insulation material. Resin bonded mineral wool conforming to IS-3183 shall be used for hot insulation. Preformed pipe sections/mattresses of min. density 120 kg/m 3 shall! be used. The minimum thickness of insulation shall be as per Appendix-1. Hot insulation shall be cladded with 26 SWG aluminum sheeting up to 14 dia. for preformed pipe sections and 24 SWG aluminum sheeting above 14 dia. pipes, equipment etc. b) Cold Insulation The insulation materials shall be : i) Resin bonded fibre-glass of 24 kg/m 3 density to IS: ii) Poly isocynurette of 24 kg/m 3 density to IS: iii) Phenolic. Foam of 24 kg/m 3 density to IS: iv) Polyurethane Foam of 24 kg/m 3 density to IS c) Underdeck Insulation 3.0 Controls and Instruments Phenolic Foam Underdeck insulation shall be of rigid slab of 25mm thickness and approx. 1000mm x 500mm size as specified and shall confirm to IS: It shall have density of 32 kg/m 3 and K Value KCal/hr M C as per BS:4370, Part 2. The insulation shall be classified as Non Combustible as per BS:476, part 5 and Class I for surface spread of flame as per BS:476, part 7. It shall be prelaminated on both sides with kraft paper. The entire soffit of slab and beams shall be thoroughly cleaned. Bituminous primer or zinc chromate primer shall be applied 0.5 kg/m 2 over the entire surface. Hot bitumen or CPRX adhesive shall then be applied on the insulation 1.5 kg/sq.m. The panels shall be pressed in position and further secured by dash fasteners. The underdeck insulation shall be fixed only after all fixtures like hooks, clamps, cleats etc. for light fixtures, ducts etc. have been fixed in the ceiling. a) Automatic operation of all controls is required, but provision shall also be made for manual operation.

10 DOC.No AA -301 DHT PROJECT Page 9 of 13 b) All controls shall be suitably interlocked for safe & sequential operation, of AC plant, c) Monsoon reheating package shall be actuated by humidistat and winter heating banks by set of thermostats. These shall operate only on running of AHU blower d) Humidifier heaters shall be actuated by humidistat. e) All electric motor driven equipments shall be provided with local Start/Stop Push button stations for operational and statutory requirements. Stop push button shall be lockable type. f) Potential free contact shall 'be provided in control panel for duplication of alarm in Owner s main panel. g) Bolts / nuts / washers of electrical equipment s terminal blocks shall be Stainless steel. h) Requirements for Reciprocating package Local Gauge panel shall be either machine mounted or floor mounted in cubicle construction provided with: Suction & Discharge Pressure Gauges. Lubricating, oil pressure gauge. Suction & Discharge Pressure Switches. Low Oil pressure switch. Oil temp gauge, Controls & Instrument section of panel shall consist of minimum following safety Features:- Selector switches for compressor Overload protection for all motors. i) Requirements for Screw package Local Gauge panel shall be either machine i) Suction & discharge pressure gauges. ii) Suction & discharge pressure switches. The Control panel shall be either machine mounted or floor mounted in cubicle construction as per manufacturer's standard and shall, consist of minimum fallowing safety features:- Low oil pressure. High bearing temp switch for motor. Overload protection for all motors. Compressor motor winding High temp. High lube oil temp to cut off heater supply. Anti freeze. High Comp discharge temp.

11 DOC.No AA -301 DHT PROJECT Page 10 of 13 Oil Filter differential pressure. Motor current limiter. To ensure minimum position of slide valve at start-up. j) Requirements for Scroll Package The Control panel shall contain at least the following control elements for the automatic operation. Compressor capacity control device. Start/stop push button station for the machine. Operation indicating pilot lamps. All safety devices and operational control elements wired to control panel. 4.0 CODES AND STANDARDS The following latest edition codes/standards shall govern: IS:659 IS:660 IS:655 IS:2494 IS:3142 IS:2379 IS-1239 (Part 1) Safety code for Air conditioning Safety code for Mechanical Refrigeration. Metal Air ducts V Belts for Industrial Purposes V - Grooved Pulley Colour Code for Identification of Pipe Lines. Mild Steel Tubes. 13: 3589 Seamless or electrically welded steel pipes for water, gas and sewage. IS:277 IS: 2062 IS:3103 IS:4894 ARI-450 Galvanized Steel Sheets (Plain and Corrugated) Steel for General Structural Purposes. Code of Practice for Industrial Ventilation Test Code for Centrifugal Fans. Water cooled refrigerant condensers. Remote Type ARI-460 Remote mechanical draft air cooled refrigerant condensers. ARI-480 Refrigerant cooled liquid coolers Remote Type.

12 DOC.No AA -301 DHT PROJECT Page 11 of 13 ARI-520 ARI-550 ARI-590 ATC-105 ASME Positive displacement refrigerant compressor & condensing units, Centrifugal or Rotary water cooled chilling package. Reciprocating water chilling package. Acceptance Test Code for Water Cooling tower. Section Code for unfired pressure vessels. TEMA. Tubular Exchanger Manufacturers Association. ASTM B-111 ASTM B-359 ASTM B-286 SMACNA AMCA-210 ASHRAE BS-6540 Part 1 13S EN 779 Standard Specification for Copper and Copper Alloys, Seamless Condenser Tubes and Ferrule Stock. Standard Specification for Copper and Copper Alloys. Seamless Condenser and Heat Exchanger Tubes with Integral Fins, Standard Specification for Seamless Copper Tubes for Air Conditioning and Refrigeration Field Service. Sheet Metal and Air Conditioning Contractors National Association. Laboratory Method of Testing Fans for Rating purposes. Handbooks of: Fundamentals HVAC Systems and Equipments HVAC Applications Refrigeration Method of Test, for atmospheric dust spot efficiency and synthetic dust weight arrestance Particulate air filters for general ventilation Requirements, testing, marking. 5.0 Performance Testing and Guarantees Performance Testing Contractor shall give two seasonal tests for (i) summer or monsoon (More stringent of the two) & (ii) winter to determine the equipment capacity and performance of the system in accordance with applicable Standards For rotary and reciprocating condensing package performance test at site shall be as per ARI 550 and ARI 590 respectively based on the available load and ambient Conditions. Period of each test shall be at least 48 hours and time for each test will be fixed up, mutually with the purchaser and/or his authorized representative.

13 DOC.No AA -301 DHT PROJECT Page 12 of 13 APPENDIX 1 INSULATION MATERIAL AND THICKNESS Sr. No. Application Insulation Material 1. Supply/Return air duct Resin bonded Form Thickness (mm) Slab/Roll 25 Fibre-glass 2. Outdoor Exposed supply/return duct -Do- -Do Refrigeration Piping Polyurethane or, Phenolic Foam or, Polyisocynurene 4. Chiller -Do- Pipe Section Slab 5. Chilled water pumps -Do- Slab Expansion tank & Associated 30 piping -Do- Slab 7. Chilled water piping, valves Pipe 40 specialties -Do- section 8. AHU Drain pipe Pipe 15 -Do- section 9. AHU Drain pan, coil & blower 15 section -Do- Slab 10. Acoustic treatment Resin bonded fibre Slab/Roll 25 Glass 11. Pan Humidifier -Do- Slab Hot Water / Steam piping Pipe 60 -Do- Section / Roll 13. Underdeck Insulation to exposed Phenolic Foam Slab 25 roof