# GTU Question papers BE- VIIth Sem – Energy Conservation and Management Nov/Dec-2011

GUJARAT TECHNOLOGICAL UNIVERSITY

BE SEM-VII Examination-Nov/Dec.-2011

Subject code: 1719

Subject Name: Energy conservation and Management

Mechanical Engineering

Instructions:

1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) Discuss in brief Energy conservation Act 2001 and its features.

(b) Define Energy management. State the basic principles and benefits of

energy management.

Q.2 (a) What do you mean by ‘Energy audit’? Discuss types of energy audit

briefly.

(b) Write note on ‘Indian Energy scenario.’

OR

(b) A domestic food refrigerator maintains a temperature of -100C. The

ambient temperature is 400C. If heat leaks into the freezer at a

continuous rate of 2kJ/s, determine the least power necessary to pump

this heat out continuously.

Q.3 (a) State key elements of Energy monitoring and targeting system. Also

discuss its benefits.

(b) Explain in brief the following:

(i) Renewable and nonrenewable energy.

(ii) Commercial and Noncommercial energy

(iv) Energy security

OR

Q.3 (a) What do you mean by Pay back period?

A co-generation plant installation is expected to reduce a company’s

annual energy bill by Rs.24 lakhs. If the capital cost of the new cogeneration

installation is Rs.90 lakhs and the annual maintenance and

operating costs are Rs. 6 lakhs, What will be the expected pay back

period for the project?

(b) The following sample data are produced during monitoring programme.

Establish Energy-Production relationship for the given foundry case.

Also Plot the Energy-production graph for nine months.

Month Production

Month        Production ton month      Energy Toe month

1          320    300

2          520    400

3          240     280

4          620     424

5          600     420

6          380     340

7          440     340

8          460     380

9          520     38 0

Q.4 (a) Using the net present value method, evaluate the financial merits of two

proposed projects shown in table. The annual rate is 8 % for each project.

Capital cost Year      Project 1                     Project 2

30000                         30000

Net amount               Net amount

Saving Amt(Rs.)       Saving amount(Rs.)

1          +6600            +6000

2          +6600            +6000

3          +6300             +6000

4          +6300             +6000

5          +6000            +6000

6          +6000             +6000

7          +5700             +6000

8          +5700             +6000

9          +5400             +6000

10        +5400             +6000

Total net saving at  end of tenth year +60000 +60000

(b) Discuss the role of Energy service companies (ESCOs).

OR

Q.4 (a) Discuss the sources of waste heat and its potential applications.

(b) With a neat sketch explain Gas turbine co-generation plant

Q.5 (a) What are co-generation plants? Explain the difference between

bottoming and topping cycle co-generation plants.

(b) A portable machine requires a force of 250 N to move it. How much

work is done if the machine is moved 25 m and what average power is

utilized if the movement takes 50s?

(c) Explain in brief Energy efficiency versus Energy conservation. Write

step wise procedure to calculate Boiler efficiency.

OR

Q.5 (a) A three phase induction 75 kW motor operates at 55 kW. The measured

voltage is 415 V, Current 80 A. Calculate the power factor of the motor.

(b) Explain the following :

(i) Reactive power and Active power

(ii) Explain the importance of TOD (time of the day) tariff

(c) Prepare a list of five measures for energy optimization in boilers and in

lighting systems.