Autumn 2009 MECH6024: Industrial Services CA Exam at Cork Institute of Technology, Exams of Industrial Engineering

Download Autumn 2009 MECH6024: Industrial Services CA Exam at Cork Institute of Technology and more Exams Industrial Engineering in PDF only on Docsity! Page 1 of 10 CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Autumn Examinations 2009 Module Title: Industrial Services CA - OPEN BOOK EXAM Module Code: MECH6024 School: Electrical & Electronic Engineering Programme Title: Bachelor of Engineering in Electrical Engineering Programme Code: EELEC_7_Y2 External Examiner(s): Mr. G. Beecher, Dr. M. Duffy Internal Examiner(s): Mr Kevin Davis Instructions: Answer 4 Questions. Questions 1, 2 and 3 must be attempted and then answer one other question. Duration: 2 hours Sitting: Autumn 2009 Requirements for this examination: This Examination paper contains answers to the exam questions and must be given to the Invigilator at the end of the Examination Note to Candidates: Please check the Programme Title and the Module Title to ensure that you have received the correct examination paper. If in doubt please contact an Invigilator. STUDENT NAME: STUDENT Number: Page 2 of 10 Q1. There are 10 parts to this question. Tick one answer only for each part of this question. If more than one answer is selected, no marks will be awarded to this part of the question. A The heat transfer when curtains are placed over windows B Heat transfer from inside to outside through the structural material of the building C Heat transfer from inside to outside through the extraction fans in the kitchen and bathroom 1(i ) What do we mean by “ Fabric Heat losses” from a building? D All of the above (2 Marks) A W/m2K B W/mK C .m2K/W 1(i i) What are the measurement units for U- Values? D W/K (2 Marks) A 7500W B 7058W C 441W 1(ii i) When the internal temperature of a sports hall is 16oC and the external temperature is -1oC, the fabric heat loss was measured as 7500W. If the internal temperature was reduced to 15oC, the new fabric heat loss would be? D 7941W (3 Marks) A 15ach B 266 m3/oC C 266 W/K 1(i v) The air volume of a sports hall is 4000m3 and the infiltration rate is 1ach. If the internal temperature is 20oC and the external temperature is 5oC, then the infiltration heat loss is given as D 20,000W (3 Marks) A Through a solid material from one surface to another B By electromagnetic waves from one solid object to another C From a solid surface to a fluid 1(v ) Convection is heat transfer….. D None of the above (2 Marks) A Kg/m2 B Kg m2 s-1 C Nm-2 D Nm 1(vi ) Pressure is defined as force per unit area on a surface where the area is at 90o to the force. The units of pressure are (2 Marks) A 47nF B 470nF C 0.00047nF 1(vii ) In SI units the following prefixes are used milli [m], micro[µ], nano[n]. What would a 0.47µF capacitor be valued in nF? D 470000nF (2 Marks) Page 5 of 10 (3 Marks) A Take up too much floor space B Are slow to heat up C Can cause some materials to discolour 2(vii i) One limitation of Radiant heating systems is that they D Heat up the air too much making the room feel stuffy (2 Marks) A Convective System B Radiant System C Direct System 2(ix ) Which of the following heating system classifications applies to radiator? D Combined System (2 Marks) A Radiation B Convection C Conduction 2(x) Which one of the following is NOT one of the three main processes of heat loss/gain from/to the human body. D Evaporation (2 Marks) Page 6 of 10 Q3. There are 10 parts to this question. Tick one answer only for each part of this question. If more than one answer is selected, no marks will be awarded to this part of the question. A The system curve is graphed in kWh per m3 s-1 B The system curve can be modified by using a VSD on the pump C The system curve can be modified by reducing the diameter of the impeller 3(i ) Which of the following statements is true? D The system curve relates pressure loss in the pipes with volumetric flow rate. (2 Marks) A 0.084 m B 0.0085 m C 8.56m 3(i i) What is the pump head if the fluid pressure is 105kPa, the density of the fluid is given as 1250 kg/m3. D 13.2m (2 Marks) Use the following information to answer parts 3(iii) to 3(v) A pump operates at 2900 RPM and delivers 0.004 m3s-1 at a pressure of 150 kPa. The pump efficiency is 75%. If the pump speed is reduced to 2600 RPM by a variable speed drive, calculate A 0.00446 m3s-1 B 16.06 m3hr-1 C 0.0026 m3s-1 3(ii i) the new volumetric flow rate D 3.58 x 10-3 m3s-1 (2 Marks) A 120kPa B 167kPa C 134kPa 3(i v) the new pump pressure D 186kPa (2 Marks) A 900W B 800W C 850W 3(v ) the old pump power is D 766W (2 Marks) Use the following information to answer parts 3(vi) to 3(viii) The design flow rate for a pumped system is 30 m3/hr. At design stage the pump head was estimated as 23 m water. Based on these figures a FCE 50-160/30 pump with a 158mm diameter impeller was purchased and installed (see attached pump curves Figure 2). When the pump was first run at the commissioning stage, the volumetric flow rate was found to be 36m3/hr. A 3.7kW B 3kW 3(v i) If throttling valves are used to reduce the flow rate to the design flow rate, what is the input power C 2.3kW Page 7 of 10 D 3.4kW (3 Marks) A 23m B 17.5m C 20m 3(vii ) What is the system Head if a VSD is used to achieve the design flow rate? D 25m (3 Marks) A 2900 rpm B 2625 rpm C 3480 rpm 3(vii i) If a VSD is used, at what pump speed will the design flow rate be achieved? D 2416 rpm (3 Marks) A A Variable Speed Drive B A Throttling valve C Trimming the impeller 3(ix ) If the flow rate of a pump is too high, it can be reduced using D All of the above (3 Marks) A room sealed flue B Condensing flue C Open flue 3(x) A balanced flue is also known as a D Combi flue (3 Marks)