Ie-JournaIArticles: RRCAT Scientists and Engineers publishtheir papers in national/international journals. All journalarticles are made available as full-text within RRCAT Infonet

through the web based Online Public Access Catalogue(OPAC), a feature available in LibSys.

All the above listed digital documents can be accessedfrom user's own desktop through RRCAT Infonet. Allbibliographical details of these digital documents can beeasily searched and full text of the files can be viewed.

Library also plans to archive conference papers andinvited talks, submitted by scientist and engineers ofRRCATto different national and international conferences.

Reported by:Rashmi Dighe (rashmid@rrcat.gov.in),

Arati Deshpande, lndu Bhushan, Dilip Tamrakm;J. K. Pattnaik and Anil Rawat

1.5: Construction & Services

A) Making of Super Conducting Radio Frequency(SCRF) building

Introduction:

The article highlights constructional features of thefacility, created for the SCRF cavity development programmeat RRCAT. Owing to the diversified and multidisciplinaryrequirement of the facility, a number of challenges in terms ofintegrated planning, designing and construction of thebuilding were faced. The building has been designed with anaim to have a complete facility for the fabrication and testingof the cavity, which includes design and validation of thecomponents required for the cavity. Salient features of thebuilding are; comprehensive building plan, for makingoptimum use of space, to satisfy functional layout andensuring required electrical power and stringentenvironmental conditions, which are essential for differentprocesses ofthe facility.

The Layout:

The building layout for such facilities though dictated bythe functional requirement and the process flow, yet needs tobe in conformity with a set of conditions put forth by services,location, ambience, ground topography etc. Selection of thetype of structure for a particular requirement is an importantdecision and should -be taken after considering abovementioned parameters. The building has been constructed astwo blocks connected by a corridor. The Air Handling Unit

INFRASTRUCTURE

(AHU) & Electrical rooms have been housed in a serviceblock which has been constructed adjacent to the PreEngineered Building (PEB).

The PEB hall has been provided with ReinforcedCement concrete (RCC) floor in M25 grade, cast usingvacuum dewatering process, which is followed by 2 mmthick, selflevelling epoxy flooring, to ensure clean space. TheAlternating Current (AlC) supply ducts have been shielded,using aluminum composite panels following profile of ductwith provision for mounting of diffusers. The planning ofbuilding also includes provision for an emergency escapedoor. Coordinate Measuring Machine (CMM) room has beenprovided with insulated composite panel false ceiling, alongwith epoxy coatings on walls and floors to ensure dustcontrolled environment. This has the added benefit ofachieving the room temperature conditions in close tolerance.Figure 1.5.1 depicts the final building plan of the SCRFbuilding. Figure 1.5.2 depicts the elevation of the completedSCRF building.

Fig. 1.5.1: SCRF building plan

Fig. 1.5.2: Elevation of the completed SCRF building

tlkRCAT NEWSLETTER Vol. 25 Issue 1, 20121

· INFRASTRVCTURE

Special features ofthe building:

+ Pre-engineered building with modified design to suit therequirement.

+ Designed for optimized space with integrated planning ofservIces.

+ Clean room finishes with epoxy flooring, painting andwall cladding using aluminum composite.

+ Efficient layout for man and material movement.+ Provision of fire safety and emergency escape.+ Emphasis on entrance lobby for aesthetics.+ Rigid, concrete floor using vacuum dewatering.+ The floor coating and colour demarcations for process

area and hidden passage, with bright yellow strip inbetween.

Figure 1.5.3 depicts the details of portal frame used for Preengineered building.

~I"''(I[C;O'7nE'~t

b) SCRFLaboratorybuilding

For illuminating the SCRF laboratory building, theground floor lab area has been equipped with surface mountedmirror optics type luminaires with 2X36W fluorescent lamps,while the first floor sitting area has been equipped with mirroroptics type luminaires with 2X36W compact fluorescentlamps. For laboratory area, wall mounted concealed lightingdistribution boards have been provided in the corridor wall.Total lighting load of the SCRF laboratory building is of theorder ono KW.

Electrical loads of the laboratory building have beencatered by laboratory area panel of 630A capacity. This panelfeeds to the wall mounted power distribution board, located inthe corridors of each floor. A well distributed network of

single phase (2X5A+ IXI5A) general purpose points, singlephase industrial type 20A metal clad and three phaseindustrial type 32A TPN metal clad power point is providedon the wall of rooms. These power points are being fed byrespective wall mounted power distribution boards located inthe corridors.

C) Air Conditioning of Clean Room High Bay and CMMhall of SCRF Building

The bay area of SCRF facility has been constructed asPEB shed and shall accommodate proposed chain of cleanrooms up to ISO class 4 with all supporting infrastructure andservices. The comfort air conditioning of the long bay and theCMM hall in SCRF building has been completed.

The 70m(L)x 20m (W) long high bay has maximumheight of 11m with multiple services running overhead, likeElectrically Operated Over Head crane, electrical cable traysand PEB trusses. The floor area shall accommodate clean

room hutches of varying heights. The tall building stratifiedair conditioning concept has been implemented for comfortair conditioning of this bay. Volume of only up to 4.5m shallbe air conditioned instead ofthe full 11m height. Consideringthat the air flow pattern may also require substantial changesafter installation of clean rooms in the 20m wide hall, thesupply air system has been designed with 1200 high blow spotjet diffusers (38 Nos) to spot (focus) the flow as per balancingand load requirements. The commissioned system has beendesigned as ducted supply & flooded return circuits, fedthrough air cooled Direct Expansion system with twodedicated double skin AHUs of 70 tonnes of refrigiration,38000 cfm x 75mm WC Double inlet double wise blowers.

All the Galvanized steel sheets ducting (~4000sqft) used werefactory made & pre fabricated on automated machinesdesigned as per Sheet metal and air conditioning contractorsassociation (SMACNA) standards. The system has beencommissioned and is working state.

I RRCAT NEWSLETTER

INFRASTRUCTURE

Fig. 1.5.5: View ofCMM Hall showing cassette airconditioning units and insulated wall cladding

Figure 1.5.5 depicts the ceiling view of the CMM Hall.The air conditionings ofCMM hall with 3 x 3TR cassette airconditioning units have been completed. It has achieved atemperature stability of 25± 10 C. The excess tonnagecapacity has been added for achieving conditions faster &better temperature stability as the bulk granite surface blockof CMM machine acts as thermal sink. The system has beenfully commissioned and is working state.

Reported by:G.Parchani, parchani@rrcat.gov.in,

Ashok Sharma, R.PAgarwal, V.Jharware, Deepak Arzare,N.Suresh, B.Rawlani, A.Pundlik, SSKulkarni.

D) Air Conditioning of Video Conference Room withfeatures like in-situ capacity adjustment and winterheating

Air conditioning of video conference room at centralcomplex building has been completed with new kind ofstandalone system meeting fresh air ventilation norms alongwith energy savings compressor capacity adjustment as peroccupancy and loads.

Video conference rooms are normally made as soundproof isolated spaces for noise free audio videocommunication. Various treatments are done on walls floor

and roof. Multiple wall claddings with air gaps, long cJrtains,thick carpets, and sound absorbing false ceiling materialalong with cushioned furniture are used. This results incontinuous release of Volatile Organic Contaminants (VOC)

_ Vol. 25 Issue 1, 201,t I

I INFRASTRUCTURE

Fig. 1.5.6: Ceiling Mounted Dual Mode Air ConditioningSystem at Video Conference Room

Reported by:Deepak Arzare (arzare@rrcat.gov.in),

R P Agrawal and S.S.Kulkarni

co~

The complete system is also used as heat pump duringwinter season by switching it to heat pump mode, thusmaintaining the room at 24 degree Centigrade without anyresistive heating even when the ambient temperature is muchless than 10 degree Centigrade. Heat pump has very highCoefficient Of Performance (COP) and consumesapproximately 250 Watt of power for an equivalent resistiveheating of 1Kilo Watt. The capital cost of installed system isIndian Rupees (INR) 35000 per ton and comparable to any 5star rated split air conditioner with substantial savings inenergy bills. The installed system has been in use and beingmonitored for other advantages and disadvantages.

11-1-1-

Video conferencing sessions are also normally held forprolonged durations with intense involved discussions ofoccupants, releasing higher C02 levels and body odors.American Society of Heating and Refrigeration Engineering(ASHRAE) standard 62-89 recommends 10-15 cfm fresh airper person to dilute odors and limit the concentration of allsuch contaminant below Threshhold Limit Value (TLV). Thusnecessary ventilation of fresh air shall be made to havehealthy sessions.

like aldehydes, ketones, benzene products and accumulateddust & fumes. All these have been reported as prime reasonsof Sick Building Syndrome (SBS) and Building RelatedIllness (BRI). Drowsiness, headache, mild asthmatic attacksand nausea are normal symptoms which are normally noticedwhen it yields as disease in long runs.

The inverter based Variable Frequency Drive (VFD)controlled air conditioning system with filtered fresh airsupplies has been commissioned for newly constructed videoconference room at central complex building. Traditional airconditioners/ refrigerators use a refrigerant compressor that iseither working at full capacity or switched off periodically, toregulate the temperature of the room. A thermostat is used tomeasure the return air temperature and switch the compressoron/off when the ambient air temperature is too far from thedesired temperature. But the installed air conditioning systemuses a VFD to control the speed of the motor and thus thecompressor. The VFD uses a rectifier to convert the incomingAlternating Current (AC) current to Direct Current (DC) andthen uses pulse-width modulation ofthe DC current within aninverter to produce AC current of a desired frequency. TheACcurrent is used to drive the brushless motor of compressor. Asthe speed of the motor is proportional to the frequency ofcurrent, the compressor runs at different speeds as per actualload-measuring return air and adjust the speed of thecompressor appropriately. This keeps the compressor inalways running mode at both part/full loads & does not havestop-start cycles which results in higher efficiencies thusextending the life of mechanical components. This helps inthe elimination of sharp fluctuations in the load. Ultimatelythis makes inverter air conditioners less prone to breakdowns,draw less current, cheaper to run, more silent - due to slowblower operations - which is required in any videoconferencing rooms. Figure 1.5.6 depicts the ceiling view ofthe video conferencing room.

~CAT NEWSLETTER Vol. 25 Issue 1, 20:if211