Download Thermodynamics Exam Numericals | ENSC 2213 and more Exams Thermodynamics in PDF only on Docsity! DISCUSSION SECTION # NAME ENSC 2213 THERMODYNAMICS Spring 2012 – EXAM 2 Instructions for taking examinations 1. Do not open the exam until you are told to do so. When told to start, put your name on each page and your discussion section number in the space provided above. 2. This test is open book, open syllabus and two pages of notes. 3. Do not exchange anything with your neighbors during the exam. 4. Show all work. Use diagrams and show control volumes as needed! Identify reference points clearly and unambiguously. Write equations in variable form before entering numbers. Answers that are unsupported will not be accepted. Cross out (clearly) or erase all work that you do not want to be graded. 5. All answers should be given to a reasonable degree of precision - usually to three significant figures. Excessive or insufficient precision will be penalized. 6. Every answer must include correct units. 7. Identify your final answer by boxing it in. 8. The examination will be stopped promptly at the appropriate time. Stop writing when told to do so and pass the exam papers towards the aisle immediately. 9. Unless you finish prior to 10 minutes before the exam finish time, please remain in your seat until all exam papers have been picked up. 10. The number in parentheses in each problem indicates the number of points for that problem. Note that problems may not be of equal weight. ENSC 2213 Thermodynamics NAME EXAM 2 / 3-2-12 2 (25) Problem 1. Each of the parts below is a separate problem. Please calculate the appropriate quantity. You do not have to draw a picture and the system is always the fluid. a) What is the specific volume of ammonia in ft3/lbm if it has a quality of 0.43 and has a temperature of 35F. b) Determine the specific enthalpy of ammonia in kJ/kg at a pressure of 0.4 bar (absolute) and a temperature of -11.2C. c) What is the specific volume of water in kJ/kg if the absolute pressure is 100 bar and the temperature is 100C. d) Air acting as an ideal gas in a closed container is heated from 500R to 700R. Calculate the enthalpy change in Btu/lbm. e) What is the specific internal energy in kJ/kg of superheated refrigerant 22 vapor at 0.09 MPa (absolute) and 7.2C. ENSC 2213 Thermodynamics NAME EXAM 2 / 3-2-12 5 (25) Problem 4. A compressor is used to increase the pressure of refrigerant 134a from 4 bar and 20C to 12 bar and 80C. The volumetric flow rate of the refrigerant entering is 4 m3/min. Neglecting kinetic and potential energy effects and assuming no heat loss and steady state operation, determine the power required, in kW. ENSC 2213 Thermodynamics NAME EXAM 2 / 3-2-12 6 Problem 1 /25 __________________ Problem 2 /25 __________________ Problem 3 /25 __________________ Problem 4 /25__________________ Total Score /100_________________
