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ENERGY AUDIT REPORT

ACKNOWLEDGEMENT

Petroleum Conservation Research Association, Eastern Region (PCRA, ER) appreciates the interest,

participation and support by the Management, Staff-members, Faculty-members and Engineers of M/s

Oil India Limited (OIL) during the tenure of the field exercises, vis-à-vis, the Energy Audit, conducted at

OIL Management Training & Development Centre, P.O. Dualiajan, Distt. Dibrugarh during the period,

05.08.14-06.08.14.

Our sincere thanks and gratitude are also to be put on record for the Management of M/s Oil India

Limited, Department of Technical Audit, L&D for their initiative for the audit and the support and

cooperation, received during the data collection, liaison and availability of necessary documents

required for the field exercises.

The Energy Audit Team for OIL Hospital, Duliajan :

On Behalf of M/s Oil India Limited On Behalf of M/s Petroleum Con. Research Ass.

Sri P.P. Sharma, Chief Manager, MTDCSri Abhijit Chanda. Addl. Director, PCRA /

Sri Debasis Datta, Jt. Director, PCRA

Sri Ranen Mandal, Chief Manager, Tech. Audit Sri Subrata Sanyal, Certified Energy Auditor

Sri Kishore Deka, Sr. Tech. Auditor Sri. Debashis Rannsingh, Jt. Director, PCRA

M/s Petroleum Conservation Research Association, Kolkata

ENERGY AUDIT REPORT

INDEX

Chapter Title Page

1.0 Executive Summery 3

2.0 Summary of Savings Potential 4

3.0 Preamble to the Report 5

4.0 Scope of Work 7

5.0 Methodology of the Audit 9

6.0 Present Energy Scenario 11

7.0 Study of Electrical Load 14

8.0 Study of Air Conditioning System 18

9.0 Study of Air Handling Unit 22

10.0 Study of Ventilation 24

11.0 Study of Illumination 26

12.0 General Observations of the Audit 30

13.0 Notes & Conclusion

Annexures

A1 Line Diagram of Electrical Power Distribution

A2 List of Energy Efficient Equipment Suppliers


ENERGY AUDIT REPORT

EXECUTIVE SUMMARY

1.0 Major Recommendations and Savings potentials :

1.1 Short and Medium Terms :

Recommendations Savings per Annum Investment (Rs.) Pay back period

KWHr Rs.

Balancing single phase loads in three phases equally

1393 6,338.00 Nil Immediate

Controlling of make-up water line in cooling tower

5,831 26,531.00 Nil Immediate

Connecting capacitor across Chiller compressor

23,460 1,06,743.00 5,475.00 ½ month

Replacing FTL by T-5 fittings in rooms/chambers

11,820 53,781.00 1,02,546.00 1 yr 11 months

Replacing FTL by CFL fittings in corridor

5,518.8 25,111.00 15,120.00 7.5 months

Replacing HPSV lamps by T-5 based fittings in compound

8,094.24 36,829.00 68,400.00 1 yr 10 months

1.2 Long Term:


ENERGY AUDIT REPORTNo recommendation

SUMMARY OF SAVINGS POTENTIAL

Replace 500 KVA power transformer by 250 KVA power transformer. It will improve the loading

on the transformer, increases its efficiency and reduce transformer losses, vis-à-vis, its loading.

Improve power factor by connecting shunt capacitor across the phases in A.C. plant feeder, it

will reduce the lagging power factor of bigger 3-ph motors in A.C. plants and cumulatively

improves the P.F. and voltage regulation at the load points,

Balance single phase loads equally among three phases and thereby, arresting the current flow

through the neutral circuit and reduction of line loss through neutral wire.

The motor loading in A.C. plant should be reduced by improving the voltage and power factor,

Connect capacitor across Chiller compressor motor to improve its voltage and power factor,

reduction of current and improving its efficiency.

Arrest excessive drainage of water from the cooling tower by controlling the makeup supply to

the cooling tower,

To over-haul Air Handling unit #3 and to arrest the leakage in the return line attached with

A.H.U. #3. The air flow circuit attached with A.H.U. #3 should be regulated/ throttled, based on

the distance of the served rooms from AHU room. The cool air-flow should be controlled to

uniformity to every room,

Install additional three exhaust fans into Guest House kitchen to improve its ventilation level,

Replace all fluorescent tube lights in chambers and rooms by energy efficient T-5 fittings. The

FTL fittings at corridors should be replaced by 18 Watt CFL lamps/ fittings. The high pressure

sodium lamps in compound lights should be replaced by T-5 based compound light fittings.


ENERGY AUDIT REPORT All lightings fittings are to be cleaned/ replaced on regular basis to improve their light-emitting

capacity. The poorly lit rooms should be provided with the fresh lights to improve their

illumination level.

Improve the illumination level in auditorium by replacing faulty lamps.

PREAMBLE TO THE REPORT

3.1 The name of M/s Oil India Limited (OIL) is synonymous with the dawn of oil exploration in India.

Since the discovery of oil fields in Digboi area in 1889 in far-east segment of present state of Assam,

the oil exploration in India had totally been shadowed by British private oil companies. In 1959, a

private-public joint venture between the Govt of India and Burmah Oil Company Limited, in the form

of a new company, Oil India Limited, was born to take over entire range of field study, infrastructure

development and oil and gas exploration in Assam. In 1981, the joint venture became a fully-owned

enterprise of Govt of India. Since then, OIL is the national oil company in the endeavour of

exploration, production and development of crude oil and natural gas in Assam, one of the major

reserves for crude oil and natural gas in India.

3.2 At present, OIL is engaged in exploration of crude oil and natural gases through 189 wells, spread

over various parts of north-eastern India, other than Rajasthan, where it is engaged in exploration of

natural gas. OIL’s exploration activities has spread over other corners of the country, namely, KG

basin, Mahanadi Basin in Odisha, Couvery basin in A.P., Andaman basin and Gujarat-Kutch basin.

New vistas of oil exploration are discovered further with the sole mission of making the country self-

sufficient in the era of crude oil and natural gas production.

3.3 OIL is having its field head-quarter at Duliajan in Dibrugarh district of Assam, around 44 Kms from

the district head-quarter. The entire town of Duliajan is the result of the activities of OIL. Major


ENERGY AUDIT REPORTinfrastructures have been developed by OIL singlehandedly and their maintenances are still being

carried out by OIL.

3.4 The OIL oil and gas exploration centres and oil/ gas collecting centres (OCS or GCS) are spread over a

vast area in Assam, Rajasthan, Odisha, Andhra Pradesh, etc. A major segment of the total staff

strength of OIL is technical, in the field of geology, mining, petroleum exploration, mechanical, civil,

electrical and other related fields. OIL, on regular basis, appoints graduate engineer trainees and

executive trainees from various premier educational Institutes of the country. During the entry level,

as well as at various mid-term level, the staff-members and engineers/ executives are imparted

proper training about the field technicalities and managerial expertise. For this purpose, a separate

‘Management Training & Learning Development Centre’ was established in Duliajan.

3.5 The double storey structure in a unique architectural fashion accommodates the class rooms and

lecture halls, separate chambers for the faculty-members and executives, hostel for the trainees in

‘Executive Training and Development Centre (ETDC)’, separate executive guest house, dining hall

and library.

3.6 As stipulated by the scope of energy audit, field surveys and data collection of installations were

carried out in Management Training & Learning Development Centre (MTDC) between 05.08.14-

06.08.14.


ENERGY AUDIT REPORT

SCOPE OF WORK

4.1 Electricity Supply and Distribution Network :

4.1.1 Detailed examination of the existing energy use of the facility with break-up

4.1.2 Measurement and analysis of the demand and power factor, suggestions to reduce the demand

and improve the power factor

4.1.3 Performance evaluation of selected motors to identify under/over loading of motors.

4.1.4 Study of V, I, KW fluctuation and profiling, V & I Imbalances in the network

4.2 Air-Conditioning System :

4.2.1 Evaluation of operating Coefficients of performances of Chiller. Evaluation of specific energy

consumption of chiller,

4.2.2 Estimation of actual tonnage and comparison of actual parameters with the design values, and

corrective actions,

4.2.3 Performance evaluation of chilled water pumping to optimize pumping power,

4.2.4 Potential of reduction in chilling requirements in working areas,

4.2.5 Measurement of electrical parameters for cooling tower fans, water flow rate, air flow rate, dry

bulb temperature (DBT), west bulb temperature (WBT), sump temperature, relative humidity,

etc,

4.2.6 Estimation and evaluation of cooling tower performance (range, approach, effectiveness) and

comparing with designed data.


ENERGY AUDIT REPORT4.3 Air Handling Units :

4.3.1 Measurement of Air-flow, RH, TSA, TRA, Chilled water Tin, Tout through cooling coil and energy

consumption of AHUs.

4.3.2 Estimation of actual Tonnage and measurement of operating zone temperatures under each

unit. Comparison of actual parameters with the designed values.

4.3.3 Examination of Air-handling units for air delivery capacity, capacity utilization, temperature

pattern, pressure drop and operational pattern wit hrespect to time to identify potential energy

saving measures.

4.4 Ventilation : Measurement and analysis of exhaust fan operating parameters/ usage pattern,

suggest measures for energy conservation.

4.5 Transformer : Study the loading/ % impedance of transformer

4.6 Lighting :

4.6.1 Examination of the lighting system in all the areas, measurement of illumination levels, etc to

improve lighting efficiency and optimizing lighting levels as per latest ECBC standard &

comparisons published by Bureau of Energy Efficiency (BEE), Govt of India

4.6.2 To look possibilities to reduce energy use by incorporating energy efficient lighting system,

equipment and lay out changes.

4.6.3 Study of operating electrical parameters in the lighting circuit.

4.7 Kitchen Equipments :

4.7.1 Examination of the existing kitchen equipments to improve efficiency and optimizing power

consumption

4.7.2 To look possibilities to reduce energy use by incorporating energy efficient equipments,

4.7.3 Study of operating electrical parameters in the kitchen equipments power circuit


ENERGY AUDIT REPORT4.8 Hot Water/ Air System :

4.8.1 To suggest inexpensive efficiency measures towards minimizing the wastage of hot water

system,

4.8.2 The power parameters (V, I, P.F. KVA, and KW) of all major equipments will be studied for

possible energy savings opportunities.

METHODOLOGY OF AUDIT

5.1 The audit has been conducted under the broad parameter of the scope of work, provided by the

OIL- Technical Audit authority. Based on the field understanding, slightest modification of the field

exercises was carried out, as required to reach proper result.

5.2 During the field exercises at MTDC, electrical and mechanical parameters of the target equipments

were tested with the help of pre-calibrated equipments. Based on the testing, the electrical

parameters, e.g. line and phase voltages, line currents, power per phase, apparent power (KVA),

power factor of individual phase, etc were noted down. Similarly on mechanical and thermal

installations, the mechanical parameters, namely, temperature, flow of liquid, suction and discharge

pressures of the pumps, speed, etc were noted. Based on the figures received, important attributes

of the installations are calculated, which are tallied with the designed data to identify the level of

effectiveness and efficiency. Even after considering the age of the installations and their operating

schedules, suggestions are meted out to improve the efficiency. If required, addition and alterations

are also suggested.

5.3 During the inspection of the equipments, their present status of operation and vulnerability towards

environment and atmospheric situation, vis-à-vis, fouling, loose connection, improper dressing,

over-heating, mechanical noises, etc, were also noted and proper remedial measures are forwarded.

5.4 During the inspections, special emphasis was given to the condition and situation at the class-rooms,

auditorium and library, to match with the standard provided for the learning centres.

5.5 Since in the MTDC, lodging facilities are also provided for the guests, executives and general staff

members, the facilities of ventilation, air condition facilities and illumination levels are tested and


ENERGY AUDIT REPORTthe figures are matched with the standard data to identify the present level of service and further

scope of development and upliftment.

5.6 During the testing, the following equipments (pre-calibrated) were employed :

Three phase and single phase power analyser,

Anemometer,

Ultrasonic Flow Meter,

Non-contact type infra-red thermometer,

Lux Meter.

5.7 During the pre-audit discussion with the officials of MTDC, the problems faced by them were also

taken a note of, which were given due consideration at the time of testing and inspection. Upto

maximum extent, the causes of their concern were identified and remedial measured are suggested.


ENERGY AUDIT REPORT

PRESENT ENERGY SCENARIO

6.1 At present, the electrical power to MTDC is available from the mega gas turbine, which generates power at 11 KV, 50 Hz, 3 Ph level. The power is made available to the indoor sub-station of MTDC, which is located at the campus of MTDC.

6.2 The single line diagram of the power distribution at MTDC :

From 11 KV Over-head, 3 Ph line

Drop-out Fuse

Power Transformer

X ACB/1600 A X ACB/ 1600 A

Incoming I Incoming II MDB 2 MDB1 CISF KVS MFP MDB 3 AC VCB FPSL 1 DB-UB Spare Colony School ACB X Plant Panel

AC Panel Through 1000 A ACB

6.3 Details of Power Transformer and Air Circuit Breaker :

Power Transformer Air Circuit Breaker11 KV/ 433 volt, 500 KVA, 26.2/ 667 Amp, 3 Ph,

50 Hz, Diagram Drawing : G84874, Year-1993,

ONAN, Impedance volt : 5.09%, vector : DYn11,

Oil : 535 litre, Sr. No. 2029233/1, make- GEC,

Tapping position - 2

Type : M-pact, 415 volt, 3 Ph, 1600 Amp, relay-

CTZM71, make-English Electric, Sr. No. 32373/91

(Incomer I) & 41319/92 (Incomer II), Year : 1991

(Incomer I)/ 1992 (Incomer II)

6.4 At present, electric energy is used for (i) lighting, (ii) fan, (iii) electronic gadgets like TV, fridge, etc, (iv) Air conditioning facility, and (v) street and compound lighting. Natural gas is used for (i) water heating, and (ii) cooking purpose at kitchen. The electrical energy is available from OIL mega gas-turbine. But, there is no energy meter fitted at the source end and at consumer (MTDC) end. Hence, accurate energy consumption pattern per month or daily load pattern could not be measured. The


Δ

ENERGY AUDIT REPORTOIL authority provided a list of energy supplied to MTDC for the period, April, 2013 to March, 2014 (it includes transmission losses, if any). The basis of their measurement is not known to us. The month-wise energy consumed at MTDC and the bar-chart are shown below :

Month Energy Consumption (KWHr)April, 2013 12,000May, 2013 20,000June, 2013 25,000July, 2013 26,000

August, 2013 27,500September, 2013 27,500

October, 2013 19,000November, 2013 11,000December, 2013 16,000

January, 2014 8,000February, 2014 8,000

March, 2014 18,000The corresponding Bar-chart :

April, '1

3

May, '1

3

June, '13

July,'13

August,

'13

Septem

ber, 13

October,

13

November,

13

December,

'13

January

,'14

February

, '14

March,'1

40

5000

10000

15000

20000

25000

30000

Series1

Observations of Electrical Energy Consumption : The average monthly consumption during the summer months are 22,429 KWHr., Maximum consumption is observed during August and September (27,500 KWHr/month), at

the time, maximum load is on A.C., Minimum load is observed in January and February (8,000 KWHr/month), which is

exclusively the load of lighting and electronic gadgets and average load per day (considering


ENERGY AUDIT REPORTthe room lights to run for 8 hours per day and street lights to run for 12 hours per day) is 258 KWHr/day.

Since there is no energy meter fitted at source or panel end, daily load chart is not possible to formulate.

6.5 The energy requirement for water heating and cooking is exclusively meted out by natural gas from own at 30 Psi level. There is no meter connected at any point of network. Nor the OIL management measures the consumption pattern at MTDC. Hence, the consumption pattern of natural gas is hard to be established.

6.6 From the observation and enquiry during the field study, electrical load usage pattern has been established as :

ELECTRICAL LOAD USAGE PATTERN PER DAY

Compound & Corridor Lights : 12 hours (6 P.M. to 6 A.M.)

Training Centre Lights : 9 hours (7 A.M. to 4 P.M.)

Guest House/ Hostel Light/ Fan : 4 hours (6 P.M. to 10 P.M.)

Individual Room A.C. : 6 hours (4 P.M. to 10 P.M.)--- 7 months per year

Central Package A.C./ Air Handling Units (3 nos) : 12 hours (6 A.M. to 6 P.M.) --- 6 months per year

6.7 As per the line diagram, the Kendriya Vidyalaya (KV) and CISF Colony are connected to the power transformer and the feeder panels. But, as the study of these two installations is not covered under the scope of present audit, the load pattern at these two units and effects on the electrical power consumption are not included into the present study.


ENERGY AUDIT REPORT

STUDY OF ELECTRICAL LOAD

7.1 As said earlier, the electric supply from mega gas turbine is available to the MTDC at 11 KV, 3 Ph

level, which is stepped down to 433 volt level by the indoor power transformer. The output from the

power transformer is fed to two separate feeder panels through two Air Circuit Breakers of 1600

Amp (rated current)/ 2800 Amp (breaking current), which are again connected through 1600 Amp

ACB bus-coupler. The double bus-bar in the feeder panels, in turn, connects to individual feeders

through mech-magneto actuated switches, which hare single phase supplies to individual feeders.

From the feeder panel, attached with incoming supply (Incomer II), a three phase feeder is provided

to Air Conditioning plant through a 1000 Amp air circuit breaker.

7.2 Neutral is made available at the secondary side of power transformer through two earthing pits

(exclusively for neutral). In the feeder panel, one phase with neutral is provided for single phase

users.

7.3 The electrical parameters measured at the power control centre (at the secondary side of power

transformer) shows the following parameters :

During Day-time (at 14:45 Hrs)

Electrical Parameters Phase- R Phase- Y Phase- B

Line Voltage (volt) 230.7 233.6 232.4

Line current (Amp) 279.4 224.6 277.7

Active Power (KW) 53.0 45.1 56.0

Power Factor 0.88 0.889 0.88

Note : The current passing through neutral at the timer of testing was 49.1 Amp.

During Evening Time (at 18:30 Hrs) :

Electrical Parameters Phase- R Phase- Y Phase- B

Line Voltage (volt) 237.7 234.0 235.1

Line current (Amp) 59.7 48.2 72.7

Active Power (KW) 11.92 9.249 13.33

Power Factor 0.84 0.82 0.78

Note : The current passing through neutral was 28.6 Amp

Observations of Electrical Parameters :


ENERGY AUDIT REPORT The capacity of the transformer is 500 KVA or 400 KW at 0.8 rated P.F. (the designed P.F. of

the transformer). As found in the testing parameter, total load (taken at 14:45 hrs on

05.08.14—it is the optimum load at a given point in the day cycle) was found 154.1 KW, i.e.

the loading on the transformer was 38.5%. At the evening time, the loading goes down to

8.62%. In both the cases, the loading on the transformer is poor.

Since the testing was done at the secondary side of the power transformer, the transformer

loss is not reflected into the test figures. It is advisable to connect an energy meter at the

incoming end of power transformer, which will reflect total electrical power consumption in

MTDC (incld transformer)

Since at the time of load testing at day-time, majority of the loads was 3-ph (i.e. load in A.C.

plant and its utilities and air handling units). Even then, the load in Y-phase (224.6 Amp) was

found less than the load in other two phases (277-279 Amp/phase). At that time, the current

passing through the neutral (an indicator for the unbalance load) was 49.1 Amp.

After 6:30 P.M., when the A.C. plant stops and almost 95% of the loads were single phase,

the situating is more alarming, as the loads are highly unbalanced and current through

neutral was 28.6 Amp (the figure is less than that in day time, because, the load in evening

time is much less than that in day time).

The power factor is also low- both in day time and evening time. Low P.F. shows higher

distribution (I2R) loss, as lower P.F. means higher current. By improving P.F. above 0.95, the

line losses can be reduced (P.F. and line current are directly proportional, whereas, the line

loss is directly proportional to the square of the current drawn).

The phase-neutral voltage is low during day time (230-233 voltage, compared to 240 volt

rated). During the evening time, it improves substantially. With proper tap position (through

trial and error method), feeder voltage should be selected to match the rated voltage.

7.4 Energy savings Potential :

Load-balancing : Single phase load un-balance and passing of current through neutral

should be arrested by almost equal loads per phase (by proper distribution among the

phases). At present, the un-balancing causes line loss = [ loss in day time for 12 hours + loss

in evening time for 12 hrs] = [ (49.1)2 + (28.6)2] x 0.197 ohm/Km x 0.5 Km x 12 hours/day x


ENERGY AUDIT REPORT365 days/year = [(2,411+818) z 0.197 x 0.5 x12 x 365] =1,393 KWhr, @ Rs.4.55/KWHr=

Rs.6,338.00

Improvement of Power Factor : As found during measurement, the P.F. is at 0.88 during day

time and between 0.78-0.84 during evening time. Since no electricity is consumed from the

grid, no monetary benefit can be accrued out of improvement of P.F. But higher P.F. ensures

(a) good voltage regulation, (b) reduction of load up to certain extent, (c) reduced voltage

drop and I2R loss is the circuit. As the load is varying between day and evening time

(inductive load is more during day time), the requirement of capacitor is to be determined

by using the formula : KVAr required = KW (tanØ1 –tanØ2) , where KW = connected load (154

KW in day time, 34.5 KW in evening time), Ø1= cos-1(existing P.F.), Ø2= cos-1(desired P.F.). The

desired level of P.F. should be 0.95. With improved P.F., the line (I2R) loss will also be

reduced by an extent of square of P.F. improvement (in percent)

Transformer Capacity : During the peak load period, the loading on the transformer is

38.5%. During the evening time or the lean (winter) period, it goes down to 8.62%. The no-

load loss of a 500 KVA transformer is 0.9 KW and load loss at 38.5% is 0.956 KW, totaling

1.856 KW (or 1.856 unit per hr). The yearly loss on internal the part of the transformer =

1.856 KWhr x 24 hours x 365 days= 16,259 KWHr. For transformer, the efficiency depends

up on the effective operating load, which goes down with lower load. Hence, it is advisable

to replace the present power transformer by a (spare) 250 KVA transformer.

7.5 Motor Testing (done for motors of 7.5 HP and above capacity) :

7.5.1 The specifications of the motors attached with A.C. plant are :

Compressor Chiller Pump Condenser Pump Cooling Tower Fan

75 H.P., 1475 RPM, 98 A, 415 V, Eff- 93.5%, no.010570, make-ABB

10 HP, 2900 RPM, 15 A, eff.-93%, sr. no. BPO20247, make-Becon

10 HP, 2900 RPM, 15 A, eff-93%, sr. no. BPO20246, make-Beacon

5 HP, 1440 RPM, 6.49 A, eff.-92%, Sr/Make-NA

7.5.2 Motor testing results :

Elec. Compressor Motor Chiller Pump Condenser Pump

paramter R Y B R Y B R Y BVoltage 229 231 230 232 234 233 231 234 233


ENERGY AUDIT REPORT

Current 86.7 91.4 89.5 14 14.4 13.5 13.7 12.9 12.2Power 17.47 18.495 18.32 2.858 2.93 2.73 2.78 2.626 2.843P.F. 0.88 0.876 0.89 0.88 0.87 0.869 0.88 0.87 0.88

7.5.3 Summery of Motor Performances :

Location Rated Load/ RPM/Efficiency

Measured Load

% loading Remarks

Chiller Compressor Motor

55 KW, 1475 RPM, Eff-93.5%

54.285 KW 98.7% Over loaded, voltage low

Chiller Pump Motor 7.5 KW, 290 0RPM, eff-93%

8.518 KW 113% Over-loaded, voltage low

Condenser Pump Motor

7.5 KW, 2900 RPM, eff.-93%

8.249 KW 110% Over Loaded

7.5.4 Observations of Motor Performances :

The voltage level (phase to neutral) at motor terminal is low (between 229-233 volt),

compared to rated voltage (phase to neutral) of 240 volts. Due to low voltages, motor

draws higher current.

The over-load settings at higher point, leading to non-tripping of relay even at much

higher load-current,

Motors are over-loaded and hence, over-heating is observed,

Motors of A.C. plant # 2 are only tested. Those of A.C. Plant # 1 could not be tested, as

that was out of order for want of gas.

Motors below 7.5 H.P. are not tested, as the efficiency of lower sizes’ motors is always

low.

Motor loading should be restricted within the range of 60%-85%, as it gives best

efficiency level of motors.


ENERGY AUDIT REPORT

STUDY OF AIR-CONDITIONING SYSTEM

8.1 Air Conditioning Plant #2 was found in operation and A.C. plant #1 was under break-down due to

want of gas. So, all parameters noted here are related to Plant #2.

8.2 The details of the installed capacities of equipments and Utilities are Noted down :

Chiller Compressor Condenser Pump Chiller Pump Cooling Tower

55 TR1, model-05066, sr. no. 01181, Pr.-26 Kg/cm2, H.S.-21 Kg/cm2, make-Voltage, Yr.1996

Capacity- 19 lit/sec, Rate dhead-29 m, efficiency-58%, make-Beacon attached with 10 HP, 2900 RPM motor

Capacity- 19 lit/sec, Rate dhead-29 m, efficiency-58%, make-Beacon attached with 10 HP, 2900 RPM motor

Natural drought, fan-FRP, attached with 5 HP, 1440 RPM motors, make-Paharpur, model-3800 series

Note : 1. The chiller capacity was given by OIL technical personnel of concerned department. No

rating was given on the name-plate.

8.3 Evaluation of Chiller :

8.3.1 The performance testing of the Air conditioning system generated the following mechanical

data :

Inlet Temperature of Evaporator 24.6oCOutlet Temperature of Evaporator 21.2oCInlet Temperature of Condenser 33.4oCOutlet Temperature of Condenser 36.1oCInlet Temperature of Cooling Tower 34.9oCOutlet Temperature of Cooling Tower 32.5oCAmbient Wet Bulb Temperature 29.2oCWater inflow to cooling tower 56.3 m3/hrWater flow rate through make-up pipe 1.39 m3/hrCondenser pump discharge 61.3 m3/hr, suction pressure -0.5 Kg/cm2,

discharge pressure- 3 Kg/cm2

Chiller pump discharge1 58.7 m3/hr, suction pressure -0.2 Kg/cm2, discharge pressure – 3.1 kg/cm2

Note : 1. Water flow at chiller pump discharge line was fully insulted by cement mortar. The flow

rate mentioned here was found just at the discharge valve of the pump.

8.3.2 Net refrigeration capacity = [(Mass flow rate of cooling water x specific heat of water x (temp

difference of cooling water at condenser inlet and outlet)/ 3024]

= [65.2 x 1000 x 1x (36.1-33.4)]/3024 = 54.33 TR


ENERGY AUDIT REPORTSo, actual tonnage of the Chilling plant is 54.33 TR, against the rate (as reported) tonnage of 55.

8.3.3 Specific Energy Consumption of Chilling Plant :

The compressor motor load = 54.285 KW, efficiency of the motor = 93.5%.

So, actual electrical power input to chiller compressor = 50.76 KW

Specific Energy Consumption = [(Actual Compressor Power)/ (net Refrigeration Capacity)]

= 50.76 KW / 54.33 TR = 0.934 KW/TR

8.3.4 Coefficient of Performance of Chilling Plant:

COP = KW refrigeration effect / KW power input = [ (54.33 x 3024)/ ((50.76 x 860)] = 3.76

8.3.5 Observations for the Chiller :

If the rating of the chiller, as reported by the concerned department of OIL is correct (55

TR), the actual TR measured (54.33 TR) is very close to the rated capacity.

The specific Energy Consumption is higher than recommended (0.84 KW/TR). It is due to

higher load of the drive motor, caused by less voltage and power factor. For same

capacity of motor, current increases with reduction of voltage and power factor. It is

recommended to connect capacitor across the motor of chiller to increase the power

factor from 0.88 to 0.98, for which capacitor of 18.515 KVAr (recommended 15 KVAr) is

suggested. The installation of capacitor will improve the voltage and power factor and

reduce the specific energy consumption. It is reduce the actual load of the motor by

around 18%, i.e. from 54.285 KW to 44.51 KW. The yearly savings = (54.285-44.51)

KWHr x 12 hours/day x 200 days/year = 23,460 KWhr/ year, @ Rs.4.55/KWhr =

Rs.1,06,743.00. Investment= 15 KVAr x Rs.365/KVAr = Rs.5,475.00. Pay-back period = ½

month.

8.4 Performance of Water Pumps : (related to A.C. Plant # 2 only)

Parameters Chiller pump Condenser Pump

Flow (m3/hr)

Discharge Pr (Kg/cm2)

Suction Pr.(Kg/cm2

Hydraulic Power (KW

58.7

3.1

0.2

4.62

61.3

3

0.5

4.16


ENERGY AUDIT REPORT

Shaft power input (KW motor x Efficiency (%)

Pump Efficiency (%)

Remarks

7.92

58.33%

Pump eff. same as the rated (58%)

7.67

54.24%

Pump eff. closer to the rated eff. (58%)

Note : The efficiency of both the pumps are very close to the rated efficiency. The figure for the chiller pump may vary slightly, if flow-rate testing can be done at exact point on the discharge line. Hence, no recommendation is meted out for the pumps.

8.5 Performance Testing of Cooling Tower :

At the cooling tower, the performances were found : Flow rate of water at inlet – 56.3 m3/hr,

Inlet temperature = 34.9oC, outlet temperature – 32.5oC, Ambient wet-bulb temp = 29.2oC

8.5.1 Cooling Tower Range :

CT range = (inlet temp –outlet temp) = (34.9-32.5)oC = 2.4oC

8.5.2 Cooling Tower Approach :

CT Approach = (outlet temp – ambient wet bulb temp) = (32.5-29.2) = 3.3oC

8.5.3 Cooling Tower Effectiveness :

CT Effectiveness = [ CT range / (CT Range + CT Approach)] = [ 2.4oC/ (2.4+3.3)oC]

= 2.4/ 5.7 = 0.42 or 42%

8.5.4 Evaporation Loss :

CT Evaporation Loss = 0.00085 x 1.8 x circulation rate (m3/Hr) x (T1-T2), where T1, T2 are cooling

tower water inlet and outlet temperatures

= 0.00085 x 1.8 x 56.3 m3/Hr x (34.9-32.5) = 0.2067 m3/Hr.

[ Note : The flow rate of water in the make-up line in 1.39 m3/Hr, out of which, (1.39-0.2067)

m3/hr = 1.1833 m3/hr is directly drained out.]

8.5.5 Observations for Cooling Tower :

Fouling is to be removed from the CT,

At present, a 1”Ø make up line is connected to the cooling tower tank with flow rate of

1.39 m3/Hr with simultaneous drain-out of almost same rate. As the evaporation loss is

quite loss (0.2067 m3/Hr), the make up line should be opened twice a day for 1 hour 15


ENERGY AUDIT REPORTminutes each time of opening. It will arrest the loss of water, @ 28.4 m3/day. (savings=

0.75 KW x 21.3 hrs/ day x 365 days/ year = 5,831 KWhr, @ Rs.4.55/KWhr = Rs.26,531.00)

The performance of the cooling tower is almost up to the mark.

SUMMARY OF STUDYPERFORMANCE :

Chiller :Net Refrigeration Capacity : 54.3 3TRSpecific Energy Consumption : 0.934 KW/TRCoefficient of Performance (COP) of Chiller : 3.76 KW/KWPumps :Efficiency of Chiller Pump : 58.33%Efficiency of Condenser Pump : 54.24%Cooling Tower :Range : 2.4oCApproach : 3.3oCEffectiveness : 42%Evaporation Loss : 0.2067 m3/Hr.

Savings Potential

By connecting 15 KVAr capacitor across compressor motor, savings/ yr =

Rs.1,06,743.00, investment= Rs.5,475.00, Payback period – ½ month

By controlling make-up water line, savings = Rs.26,531.00/year,

investment -Nil


ENERGY AUDIT REPORT

STUDY OF AIR HANDLING UNIT

9.1 There are three Air Handling Units (AHU) for MTDC, #1 located at Library, which has two ducts- one

for library and other for first flow chambers, #2, located at first floor, meant for a part of FF

chambers and auditorium, #3 located at ground Floor, meant for all class rooms and chambers in the

ground floor.

9.2 Out of three, AHU #1 & 3 were checked, as #2 was not operational (works only when there is any

programme in the Auditorium).

9.3 Testing of A.H.U # 1

9.3.1 Measured Parameters : (i) Incoming Hot air- 28.3oC at 67.6 % RH, (ii) Outgoing cool Air – 16.2oC

at 81% RH, (iii) Volume of air flow = 3.46 m/sec x 2.64 sqm = 9.1344 cum/sec, (iv) Power

measured : 227/224/236 volt, 6.1/6.4/5.7 Amp, KW-3.63, P.F.-0.88

9.3.2 The enthalpy at inlet and outlet air at measured humidity : 71.2 KJ/Kg and 39.5 KJ/Kg. The air

mass flow per hour = 9.1344 cum/sec x 3600 sec = 32,884 m3/hr at 1.2 Kg/m3 density

9.3.3 Heat Load = [ air flow/hr x density of air x diff in enthalpy]/ (4.18 x 3024) = [32,884 x 1.2 x (71.2-

39.5)]/ (4.18 x 3024)]= 98.96 TR

9.4 Testing of A.H.U # 3

9.4.1 Measured Parameters : (i) Incoming Hot Air – 28.4oC at 66% RH, (ii) Outgoing cool air – 21.2oC at

85.9% RH, (iii) Volume of air flow = 4.535 m/sec x 1.76 sqm = 7.9816 cum/sec= 28,734 cum/hr.

9.4.2 The enthalpy of air at inlet and outlet at measured humidity : 68.5 KJ/Kg and 57.2 KJ/Kg

respectively

9.4.3 Heat Load = [ air flow/hr x density of air x diff in enthalpy]/ (4.18 x 3024) = [28,734 x 1.2 x (68.5-

57.2)]/ (4.18 x 3024) = 30.82 TR

9.5 Measurement of Operating Zone Temperatures :

Location Air Flow rate Temperature/RH Dist. from AHU Outlet opening

Class Room #1 GF 3.78 m/s 22.2oC at 71.9% 26 mtr 0.09 sqm

Room #4, GF 1.47 m/s 23.9oC at 70.9% 33.54 mtr 0.1 sqm

Class Room #3 GF 4 m/s 22.7oC at 74.9% 12.2 mtr 0.1 sqm

Room # 1 GF 2.73 m/s 26.1oC at 65.5% 19 mtr 0.1 sqm


ENERGY AUDIT REPORT

9.6 Observations of AHU Performances :

9.6.1 The designed specifications of the Air Handling Units, along with the duct circuit could not be

made available. Hence tallying the current performances with the specified performances could

be tallied.

9.6.2 A.H.U. # 2 could not be tested, as it was not operational during the test period,

9.6.3 As understood, there is no duct for the return line and the return flow passes freely in the space

between the roof slab and the false ceiling. Near the toilet of GF (while moving towards the

ETDC area), the false ceiling was found dislocated, leading to escape of air through the opening.

9.6.4 The rooms at the far-off from the respective AHU are found less cooled, as the measured air

flow rate and the delivered air temperatures sufficiently justified. The more is the distance from

the respective A.H.U., the less is the air flow.

9.6.5 There are certain points of air throttling, which ultimately reduces the air flow at different

rooms. The room temperature at closer to A.H.U.#3 is much less and less comfortable. Whereas

the rooms at a distance of 30 mtrs and above are quite hot, though the temperature at the

opening is around 22oC. It is happening because there is less air flow into the room.

9.6.6 The heat load for A.H.U. #3 is 30.82 TR, which is to cover an area of 357 sqm in ground floor, i.e.

specific cooling coverage = 0.086 TR/m2, whereas the recommended criterion is 0.04 TR/m2.

Whereas the heat load for A.H.U #1 is 98.96 TR, which is covering the rooms at first floor a swell

as entire library, covering 1954 sqm, i.e. the specific cooling coverage is 0.0506 TR/m2

(recommended is 0.04 TR/m2). So the effectiveness of A.H.U. # 1 is better than #3.

9.7 Suggestions about Air Handling Units & Air Duct :

9.7.1 Thorough over-hauling of A.H.U. #3 is required to be done immediately,

9.7.2 Plug all opening in the return line of air flow in A.H.U.#3,

9.7.3 Throttle/adjust the air passage to individual rooms, e.g. through the air flow based on the actual

distance of the served room from A.H.U. and open for the distant rooms (the cooling air duct

circuit could not be provided by the concerned department of OIL at the time of audit)


ENERGY AUDIT REPORT

STUDY OF VENTILATION

10.1 There is single area in the closed enclosures of MTDC, where ventilation poses importance is the

kitchen of the Hostel cum Guest House.

10.2 The present situation of the kitchen is :

Kitchen Area (enclosed) 82.54 sqmSource of Heat generation

8 nos of gas ovens, out of which, 5 run at a time during the cooking

Window/open door area Door area= 1.4 m x 2.1 m + 1.7 m x 2.3 m = 6.85 sqmWindow = 4 nos x 1.2 m x 0.9 m = 4.32 sqmTotal area of natural opening = 11.17 sqm

No of exhaust Two of 50 cm sweep (one is not running)Room Temperature Av. (during cooking period) – 33oC at 72% RHAmbient temperature At day time – 33oC (summer), 24oC (winter)

At evening time- 29.6oC (summer), 18oC (winter)

Air velocity at forced exhaust

4.37 m/sec.

Number of persons present at a time

Six (6)

10.3 Calculation of Heat generation inside the Kitchen & its exhaust :

10.3.1 Volume of Air inside kitchen = 82.54 sqm area x 3.35 m high= 276.509 cum

10.3.2 Heat generated inside kitchen = volume of air x sp. Heat in Kcal/cum/oC x difference between

room temp and ambient temp = 276.509 m3 x 0.311 kCal/m3/oC x (33-29.6)oC= 292.38 kCal

10.3.3 Heat generation per sec inside kitchen = 292.38 kCal/sec

10.3.4 Area of the exhaust fan = (3.14 x .25)/4 = 0.196 sqm

10.3.5 The mean velocity of exhaust fan = 4.37 m/s

10.3.6 Rate of hot air exhaust/ sec (forced draught) = 0.196 sqm x 4.37 m/sec = 0.857 cum/sec.

10.3.7 Rate of hot air exhaust through another exhaust fan opening (natural draught) = 0.39 sqm x 0.8

m/s = 0.312 cum/sec.


ENERGY AUDIT REPORT10.3.8 Rate of hot air exhaust (natural draught) through windows & doors (50% of the open area) = ½ x

11.17 sqm x 0.8 m/sec = 4.468 cum/sec.

10.3.9 Total rate of hot air exhaust = (0.857 + 0.312 + 4.468) = 5.636 cum/sec.

10.3.10 276.509 cum air at 29.6oC becomes 279.61 cum at 33oC, which is to be exhausted forcefully with

average rate of 5.636 cum/sec. A part of hot air is also being going out through the windows, as

the ovens are located very close to the window.

10.3.11 So, the present ventilation during summer is grossly inadequate to take out hot air from the

kitchen, where fresh three exhaust fans are to be installed to take out entire range of hot air.


ENERGY AUDIT REPORT

STUDY OF ILLUMINATION

11.1 Details of the Fittings of lights and fans in various rooms of MTDC are tabulated as given :

Location Light fitting Wattage Total Load Fan no. Wattage Total load

Chambers- 1-6

26 FTL (36+12)= 48 1.248 KW 6 60 0.36 KW

Class Rooms 1-3

34 FTL (36+12)=48 1.632 KW 7 60 0.42 KW

Auditorium 6 CFL14 CFL37 CFL

75 1815

0.45 KW0.252 KW0.555 KW

0 0 0

Corridor 24 FTL (36+12) =48 1.152 KW 0 0 0Dining Hall for ETDC

19 FTL (36+12)=48 0.912 KW 5 60 0.3 KW

ETDC Class Room-2

32 FTL (36+12)=48 1.536 KW 12 60 0.72 KW

ETDC Office 12 FTL (36+12)=48 0.576 KW 3 60 0.18Guest Room 22 FTL (36+12)=48 1.056 KW 22 100 2.2 KWLounge 4 CFL

2 FTL2 FL

234860

0.092 KW0.096 KW0.12 KW

1 100 0.1 KW

Corridor 18 FTL4 CFL

489

0.864 KW0.036 KW

0 0 0

Dining Hall 25 CFL6 FL

2360

0.575 KW0.36 KW

6 100 0.6 KW

Hostel Room

96 FTL 48 4.608 KW 48 100 4.8 KW

Compound lighting

12 HPSV20 CFL

250 23

3 Kw0.46 KW

0 0 0

Total 19.58 KW 9.68 KW

12.1 Measurement of Illumination Level at various points :

Location Measured Lux Recommended Lux RemarksRoom # 4 GF 77.75 300 Poorly lit, wall not

reflectiveRoom #3, GF 66.86 300 Same as aboveClass Room # 1 99.71 300 Unequal distributionClass Room #2 101.9 300 Unequal distributionAuditorium (Dais) 28.875 300 Poorly lit, 7 fusedAuditorium (Audience) 23.8 100 Poorly lit, 20 fused


ENERGY AUDIT REPORT

Corridor (ETDC) 32.75 100 To be improvedETDC Dining Hall 105.21 150 Up to date, 10 fusedETDC Class Room 147.94 300 To be improvedETDC Office 128.25 300 To be improvedRoom #5, GF 65.375 300 Poorly lit, wall not

reflectiveG.H. Room #111 11.125 150 Poor lighting, fixture to

be cleanedG.H. Room #115 20.375 150 Same as aboveG.H. Room #102 36.5 150 Same as aboveExecutive Lounge 41 200 Curtain to be provided

in window, wall not reflective

G.H. corridor 14.96 100 Poor lighting, 2 fusedDining Hall 32.30 150 Unequal distribution, 7

fusedCorridor between G.H. & MTDC

23.9 100 Poorly lit

Hostel Corridor 18 100 Poorly lit, wall not reflective

Hostel Room #124 45.17 150 Same as aboveHostel Room #114 35.33 150 Same as aboveHostel Room #103 41.8 150 Same as aboveHostel Room #208 34.71 150 Same as above

12.2 Calculation of Installed Load Efficiency Ratio :

LOCATION PHISICAL PARAMETERS VALUE

Room No.4, G.F. Interior floor area of the roomRoom IndexTotal circuit wattWatt/SqmEav.MaintainedLux/w/sqmTarget Lux/Watt/sqmInstalled Load Efficiency Ratio (ILER)Remarks

17.5 sqm

1.02144 watts8.2390.2510.97360.3047

Urgent action requiredClass Room #1, G.F. Interior floor area of the

roomRoom IndexTotal circuit watt

64.9 sqm

1.92504 watts7.77


ENERGY AUDIT REPORT

Watt/SqmEav.MaintainedLux/w/sqmTarget Lux/Watt/sqmInstalled Load Efficiency Ratio (ILER)Remarks

99.7112.83460.2789

Urgent action required

ETDC Office Interior floor area of the roomRoom IndexTotal circuit wattWatt/SqmEav.MaintainedLux/w/sqmTarget Lux/Watt/sqmInstalled Load Efficiency Ratio (ILER)Remarks

84 sqm

1.768432 watts5.14128.6725.03440.5688

Review suggestedETDC Class room Interior floor area of the

roomRoom IndexTotal circuit wattWatt/SqmEav.MaintainedLux/w/sqmTarget Lux/Watt/sqmInstalled Load Efficiency Ratio (ILER)Remarks

91 sqm

1.82576 watts6.33153.2424.21450.538

Review suggestedGuest House Room No.#111 Interior floor area of the

roomRoom IndexTotal circuit wattWatt/SqmEav.MaintainedLux/w/sqmTarget Lux/Watt/sqmInstalled Load Efficiency Ratio (ILER)Remarks

17.5 sqm

0.82336 watts2.0611.1255.40350.1542

Urgent action required

12.3 Observations and suggestion about Illumination :

Around 30% of the light-fittings were found fused or not fitted,


ENERGY AUDIT REPORT The room dimensions are not fully rectangular, so distribution of lights are not uniform and

are often restricted,

The compound lightings are found insufficient and around 25%-30% increase is

recommended.

In almost all rooms, illumination level is less than what is required and suggested. In MTDC

chambers and Guest House rooms, level of illumination is to be improved and acrylic covers

are to be cleaned/replaced periodically.

In the corridor, 18 watts CFL fixture can be fitted in place of 36 watt FTL (actual load is

36+12= 48 watts), which is improve the colour rendering facility and depth of penetration

for short height.

All FTL (36 watts) are to be replaced by T-5 fittings,

In the hostel rooms, wall colour is to be changed, making it more reflective. Otherwise,

present level of illumination inside the hostel rooms is too poor for young students to

concentrate in study.

12.4 Energy Savings Potential :

By replacing 36 watts FTL by T-5 fittings (other than corridors). Net savings = 243 nos x (48-

29) watts x 8 hours (av)/day x 320 days/year (av) = 11,820 KWhr/ year, @ Rs.4.55/KWHr=

Rs.53,781.00. Investment- 243 nos x Rs.422.00/no = Rs.1,02,546.00. Simple pay-back period

= 1 year 11 months.

By replacing FTL corridor lights by 18 watts CFL lights, savings = 42 nos x (48-18) watts x 12

hours/day x 365 days/year = 5,518.8 KWhr., @ Rs.4.55/ KWhr = Rs.25,111.00. Investment=

42 nos x Rs.360.00/no (incld fittings) = Rs.15,120.00. Simple payback period= 7.5 months.

By replacing 250 watts compound HPSV lights by T-5 fittings (24 watts x 4 nos), savings = 12

nos X (250-96) watts x 12 hours/ day x 365 days/year = 8,094.24 KWhr, @Rs.4.55/KWHr=

Rs.36,829.00. Investment – 12 nos x Rs.5,700.00 = Rs.68,400.00, Simple pay-back period – 1

year 10 months.


ENERGY AUDIT REPORT

GENERAL OBSERVATION OF THE AUDIT

Management Training & Learning Development Centre (MTDC) is a well-knit establishment of

M/s Oil India Limited, which houses, other than the training centre, hostel, guest house and

Executive Training Centre. The building is a double storey RCC structure, consisting of a number

of blocks, meant for different purposes, connected by shedded corridor.

The power supply is made available from OIL source and hence, the conventional tariff

structures for bulk consumers are not applicable here. As the system in OIL lacks in the provision

of meters for consumption level, it is not possible for MTDC to monitor its consumption level at

a regular interval.

The distribution transformer is poorly loaded, highlighting its own efficiency pattern and total

effective life. No operation log-book is maintained here, giving one no clue for the performance

in the historic basis.

The Air condition plant is the biggest single consuming point, consisting of 100 H.P., 3 Ph loads.

It consists of 85% of total consumed load and runs for 12 hours a day for seven months a year.

During the lean period, the drawn load reduces substantially, putting the transformer at

abnormally low level.

The distribution of cool air in all designated rooms is not uniform. As all of the rooms are

subjected to direct sun exposure throughout the year (due to typical architectural configuration

of the building), the controlled temperature feelings are not healthy.

The light fittings are also no uniformly designed and a substantial section of it was found fused,

leading to poor illumination level. Efforts are to be given to ensure sufficient lights at class room,

chamber and dwelling rooms, where poor illumination level often causes discomfort.

The earthing at all point was found sound and no further action is to be taken.

Consumption meters are to be provided at the gas consuming points and the running of baby

boilers, as these are found to be run for uncontrolled way with availability of hot water at the

toilets at even unwarranted time.

Door closures at individual rooms and lounges are to be fixed properly, so that cool air should

not go out of the room, putting extra load on the air conditioners.


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