# GTU Question papers BE- VII th Sem – Energy Conservation and Management May/June-2012

GUJARAT TECHNOLOGICAL UNIVERSITY

BE- VII th SEMESTER–EXAMINATION – MAY/JUNE- 2012

Mechanical Engineering

Subject code: 1719

Subject Name: Energy conservation & Management

Instructions:

1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) 1. Define energy conservation with suitable example

2. List four important duties of energy manager in

industry as per Energy conservation act-2001.

(b) Explain need of energy sector reforms in India.

Q.2 (a) Define following terms.

1. Power Factor 2. Load Factor 3. Calorific Value

4 Latent Heat of Vaporization 5. Humidity

6. Commercial Energy 7. Energy Intensity

(b) The energy consumption of a industry per month is

2,50,000 units. The contract demand of a plant is 1200 kVA.

The minimum billing demand is 75% of the contract demand.

The basic tariff structure is as follows :

Demand Rate : 0-500 kVA = Rs. 200/kVA

501-1000 kVA = Rs. 180/kVA

Excess over 1000 kVA = Rs. 150/kVA

Energy Rate : Rs. 5.00 for the first one lakh units/ month

Rs. 4.50 above one lakh units/month

Fuel Surcharge : Rs. 0.20 per unit/month

Service Tax : Rs. 0.30 per units/month

Meter rent : Rs. 250/month

Calculate the cost of monthly electricity consumption.

OR

(b) The following are the data collected for boiler using furnace oil as a fuel.

Carbon content in fuel =84%

Hydrogen content in fuel =12%

Moisture content in fuel =0.5%

GCV of fuel = 10000 kCal/kg

Surface temperature of boiler = 80 0C

Humidity in ambient air = 0.025 kg/kg of dry air

Mass of dry flue gases =21.36 kg/kg of oil

Actual mass of air supplied/kg of fuel = 21.49 kg/kg of fuel

Flue gas temperature =190 0C

Ambient air temperature = 30 0C

Specific heat of flue gases = 0.23 kCal/kg0C

Specific heat of super heated steam in 0.45 kCal/kg0C

Radiation & convection losses = 0.38%

Losses due to incomplete combustion= 0.01%.

Find out the boiler efficiency by indirect method.

Q.3 (a) List the elements of monitoring & targeting system with its

function.

(b) Explain Simple pay back method with its advantage &limitation.

OR

Q.3 (a) Explain Sensitivity Analysis & List the micro & macro

factors.

(b) 1. Explain the role of Energy service companies. (ESCOs.)

2. Define following terms.

(i) CUSUM (ii) ROI (iii) Monitoring

Q.4 (a) 1. Define energy audit as per the energy conservation act-

2001.

2. Explain why compact fluorescent lamp is used for

energy efficient lighting controls.

(b) What do you mean by cogeneration? Classify cogeneration

system & Explain bottoming cycle.

OR

Q.4 (a) Classify the energy audit & Explain the three phases of

detailed energy audit.

(b) 1. List the benefits of heat recovery system.

2. List the energy saving opportunities in refrigeration

Air-conditioning plant area.

Q.5 (a) Calculate ILER value & annual energy wastage for the

following.

Floor area of the interior room = (9 X 5) Meter2.

Mounting Height = 2 meter

Total circuit watts of the installation by power meter = 990 W

Average maintained illuminance =700 lux

As per the color rendering index table ,Target load efficiency

= 46 lux/W/m2

No. of operating hrs/day =8

No. of operating days/annum =300.

(b) 1. List the various types of heat losses in furnace.

2. Classify the different types of steam traps with their principle.

OR

Q.5 (a) List the suggestions for improving the efficiency in

compressed air system.

(b) List the seven important suggestions for energy saving in

pumps & fans.