Universiti
Malaysia
Q PAHANG
Engineering • Technology • CreatIvity
FACULTY OF ENGINEERING TECHNOLOGY
FINAL EXAMINATION
COURSE
:
ENERGY AUDITING
COURSE CODE
:..
BTV3453
LECTURER
:
RQZIAH ZAILAN
SAMSON MEKBIB ATNAW
DATE
:
20 JUNE 2016
DURATION
:
3 HOURS
SESSION/SEMESTER :
PROGRAM CODE
:
SESSION 2015/2016 SEMESTER II
BTV/BTM
INSTRUCTIONS TO CANDIDATE:
1. Answer ALL questions.
2. All the calculations and assumptions must be clearly stated.
3. Candidates are not allowed to bring 'any material other than those allowed by the
invigilator into the examination room.
EXAMINATION REQUIREMENT:
1. Nil.
DO NOT TURN THIS PAGE UNTIL YOU ARE TOLD TO DO SO
This examination paper consists of FIVE (5) printed pages including front page.
BTVIBTM/151611JBTV3453
CONFIDENTIAL
QUESTION 1
a) Mr. Aaron was appointed as an energy auditor for the Pusrawi Hospital. He took
about three months to complete the project and submit the energy audit report.
Recommend the energy audit format report in the appropriate sequences.
(7 Marks)
b) The recommendation of energy saving measures (ESM) is the main key in an audit
report. Point out THREE (3) categories of proposed ESM and identify TWO (2)
recommendations for each category.
(6 Marks)
C)
A room size lOm x lOm was installed with 20 tubes normal T8 36W fluorescent lamp.
As an energy auditor, the new proposal to lighting up the room efficiently is by
replacing it with new T5 26W fluorescent lamp. The daily operation hour is 10 hours
a day and 250 days a year. Analyze the system in order to answer the following:
i.
Calculate the annual electricity saving.
(5 Marks)
ii.
How much is the annual cost saving according to TNB tariff at
RMO.297/kWh?
(2 Marks)
QUESTION 2
a)
Discuss relationship between electricity generation, transmission & distribution.
(5 Marks)
b) The power factor penalty (surcharge) for customers operating at lower power factor
set by TENAGA NATIONAL BERHAD with electricity supply below 132 kV is
calculated as follows:
• 1.5% surcharge of the current bill for every 0.01 less than 0.85 power factor.
• 3% surcharge of the current bill for every 0.01 less than 0.75 power factor.
i.
Calculate the total surcharge for a user operating at a power factor of 0.8 with
current monthly bill amount of RM1O,000.
(4 Marks)
ii.
Calculate the total surcharge for a user operating at a power factor of 0.65 with
current bill amount of RM1O,000.
(6 Marks)
2
CONFIDENTIAL
iii.
BTV/BTMJ1516IIJBTV3453
Considering part b), comment on the financial feasibility by calculating the
payback period of investing on a capacitor bank of total installation cost RM
3.0,000 in order to increase the operating power factor to 0.9. Assume the
monthly bill for the company to remain at RM.10,000 throughout the year.
(5 Marks)
QUESTION 3
a)
Electric motors typically account for 70% of the electricity usage among industries.
Therefore, higher efficiency in motors will result in substantial savings in energy and
electricity costs. Discuss FIVE (5) potential losses of energy from inefficient motors
and propose the solution in order to improve the efficiency.
(10 Marks)
b)
Taylor hotel needs a new 60 HP pump. It is expected that the pump will be running on
full load for 6,000 hours per year. A local supplier has proposed two types of motors.
The first type is a standard motor with 91% efficiency costing RM10,000. The second
type is a high efficiency motor with 95% efficiency costing RM1 1,880. The average
electricity rate including peak and off-peak electricity as well as maximum demand
cost charged to the hotel is RMO.24/kWh.
Considering that the expected life of the motor is 10 years and using Simple Payback
Period (SPP), comment whether it is a good investment for the hotel to buy the high
efficiency motor?
(10 Marks)
BTVIBTM/151611/BTV3453
CONFIDENTIAL
QUESTION 4
a)
Discuss the relationship between chiller, cooling tower and air handling unit (AHU)
with a proper sketch.
(5 Marks)
b)
In building system, air-conditioning system consumes 70% of the energy
consumption. An energy services company, ABC Engineering was audited chiller
plant at Building X and recorded the finding in Table 1. Determine air conditioning
performance and identify status of the chiller plant based on ASHRAE indicator
provided in Figure 1.
Table 1. Chiller Plant Energy Audit Result.
Figure
Description
1221/s
Measured Flow Rate
425.96 kW
Chiller
4.03 kW
Condensor Water Pump
(CWP)
18.96 kW
Cooling Tower (CT)
7°C
Chill water temperature
supply
Chill water temperature
return
Plant power input
Total Heat Rejection
10.7°C
?
?
NnoT.dsolngy fiffi$ency Cotoo
AJ1.Vateb$, Spn.
Cht.r PleMi
/
Optmlaod Codo Bmod
Ch5, Ptnn Ch*., Plait;
I
I
Chillof Plete mi
Cmmdabla Omm a
Omitaat Fabian,
I
_________ FAIR
I
I
I
1.1
1.2
0.6
0.7
0.8
0.9
1;0
kW/ton 0.5
C.O.P. (7.0) (5.9) (5.0) (4.4) (3.9) (3.5) (3.2) (2.9)
AVERAGE ANNUAL CHILLER PLANT EFFICIENCY IN KW/TON (Cap.)
(Input energy In eludes chillers, condenser pumps and tower fans)
BaseMan eleculcallyteiven cenalal chute, Plants in comlaiiconMMonlhg
ipiftitions wth 42P(&6C) nominal chilled water eupply tmnpofalwe and cpe.
annung tenors stsed lit, 85F (2&4C) mwdnwmetitnelngconcnstfnotsttempetMtIf
Lanai Climate adJuslment for NOMh MaiAc.n chmalas is .1 0415 lIWeell
Figure 1. Average Annual chiller plant efficiency based on ASHRAE.
(10 Marks)
4
CONFIDENTIAL
C)
BTVIBTM/15161I1BTV3453
Discuss finding of air conditioning performance and provide solution if any.
(5 Marks)
QUESTION 5
a)
Discuss FIVE (5) potential losses of energy that influence the energy efficiency of
compressor and propose the energy efficiency opportunities of compressor
accordingly.
(10 Marks)
b)
Factory D operates a compressor station consisting of four screw type single stage aircooled compressor units. Two units are always in operation and the compressed air is
distributed in a loop system. Based on a "no-load test' ' at the compressed air system, it
was found that the total leakage of the whole system is 64% of the compressed air
delivered. Of this, 13.5% of the air leakages were found at the main distribution loops.
Upon recommendation, the factory carried out the leakage repair works, resulting in
the need for only one compressor in operation, while the other is always on standby
mode. The estimated saving from this measure is listed below. Calculate the annual
cost saving, payback time and CO2 reduction (0.74 lkgCO2/kWh). Comments your
answer.
Item
specific
Previous
Consumption
specific
Current
consumption
Specific energy saving
Projected production
Energy saving
Electricity cost
Saving cost
Investment.
Simple payback period
CO2 reduction
Unit
kWh/tonne
Figure
39.28
kWh/tonne
34.52
kWh/tonne
tonne
kWh
RMIkWh
RM
RM
year
tonne
4.76
10,119
0.258.00
4,000.00
?
?
(10 Marks)
END OF QUESTION PAPER
5