Air Conditioning

Planning

Requirements

The job of a refrigeration plant is to cool articles or substances down to, and maintain them at a temperature lower than the ambient temperature. Refrigeration can be

defined as a process that removes heat.

•Foodstuff conservation•Process refrigeration•Air conditioning plants•Drying plants•Fresh water installations•Refrigerated containers•Heat pumps•Ice production•Freeze-drying•Transport refrigeration

There are countless applications for

refrigeration plants now. Examples are:

Refg Cycle

Refrigerants

R134a, which is a substance of the ethane group with the formula CH2FCF3 and has a normal boiling point of –26.1 °C.

R22, which is a substance of the methane group with the formula CHF2CI and has a boiling point of –40.8 °C.

R404A/R507A (also known as R507), which is a mixture of the refrigerants R125 (CHF2CF3) and R143a (CH3CF3) with a boiling point at (–46.7 °C) which is slightly lower than for R22.

R407C, which is a mixture of the refrigerants R32 (CH2F2), R125 (CHF2CF3) and R134a (CH2FCF3) with a boiling point at (–43.6 °C) which is slightly lower than for R22.

R410A, which is a mixture of the refrigerants R32 (CH2F2) and R125 (CHF2CF3) with a boiling point at (–51.4 °C) which is lower than for R22. Its thermodynamic properties make it suitable as a refrigerant for medium and high temperature applications in residential and commercial air conditioning.

Refg Cycle

Split AC

Central AC Plants

Direct Expansion

Type

Chilled water Type

Chilled Water AC Plant

AC Plant Description

• Supply, install, test & commissioning of Micro-processor controlled Water-cooled screw Chiller Type Air conditioning plant of capacity full load not less than 160 TR and with 1 x 80 TR as stand by to meet 50% of full load capacity of heat load suitable for complete operation with refrigerant R-22 with all equipments and accessories complete for Service support centre at AF Station x to meet the inside design condition of temp 22 + 20C and relative humidity 60 + 10% and technical parameters as per annexure ‘D’ attached and comprises of the followings :-

AC Plant Description

• Note :- (i)The tenderer should ascertain the correctness of heat load calculations and technical parameters given in Annexure D based on the building plan outside/inside parameters and design parameters as given in the tender and quote accordingly.

• (ii)The tenderer shall be responsible for the plant to meet the design condition round the clock on 24x7x365 basis irrespective of the full load capacity given in the schedule, which is given on not less than basis.

• (iii) The tenderer should got the plant installed by any of the original manufacturer viz Voltas/Blue star /carrier with their recommended makes of complete components/items.

• (iv)In case of any change in the technical parameter given in .Annexure D, to provide the design parameters the tenderer should furnish the same along with tender.

Chiller Plant Description

(A) Three Nos water cooled screw Chilling units complete and each comprising of the following :-

(i) Screw compressor, hermetically sealed type directly coupled with refrigerant cooled squirrel cage induction motor to run on 3 phase 50 HZ 440 volt as per tech detail attached in annexure ‘D’ complete with suction and discharge piping, automatic capacity control with thermostat, suction strainer, crank case heater, compressor oil, internal overload trip, safety switch with gauge panels complete with HP/LP cutouts, anti freeze and refrigerant cooled motor as specified.

(iii) One No shell and tube type water cooled condenser with MS shell and integrally finned copper tubing, complete with safety valves, drain valve, water inlet and outlet valves, hot gas inlet and liquid outlet isolating valves thermometer and pressure gauges at inlet and outlet and purge valves all as specified and as per technical specification attached in annexure ‘D’. (ii)one No shell and tube type direct expansion chiller units having plain copper tubes all as specified ad as per manufacturers design.

(iv) One no stand fabricated of suitable size duly painted with two coats of black synthetic enamel paint over one coat of red oxide primer for mounting compressor, motor, and condenser etc of above specification.

Chiller Plant Description

• (vi) Refrigerant piping complete will all required fittings and accessories with necessary bracket and support to interconnect compressor, cooler, condenser and expansion valves including insulation of suction lines with fire resisting insulating material of adequate thickness as per manufacturers specifications.

• (vii) Micro processor based control comprising for following features :-

– (a) Automatic capacity control reducing energy consumption. – (b) Micro processor controlled pump down system. – (c) Micro processor based sequence of starting/stopping of

equipment with fixed time delays. – (d) Alarm history giving cause of tripping. – (e) Data scanner system including operating constitutions. – (f) Oil pressure failure cut out LP/HP cut out. – (g) Liquid line indicator.

Chiller

Compressor

Compressor

Expansion Valve

Expansion Valve

Cooling Tower

AHU & Ducts

AHU & Ducts

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