1. A process steam plant has a flash vessel operating at following conditions (15 marks) Condensate flow 8,000 kg/h Co
Posted: Fri Jul 01, 2022 6:40 am
1. A process steam plant has a flash vessel operating atfollowing conditions (15 marks) Condensate flow 8,000 kg/h Condensate pressure 8 barg Flash steam pressure 3 barg (Required for process)
Draw a diagram for this process and find, a. Liquid enthalpy before flashing b. Liquid enthalpy after flashing c. Enthalpy of evaporation of flash steam d. Flash steam rate in kg/h
2. Select the suitable pipe sizes for 3 barg, 5 barg, 6 barg, 10barg and 14 barg for dry saturated steam through long steam pipes which carries 2000 kg/h.What is the pipe selection criteria in this case? (Refer to Table 10.2.4) (12marks)
3. Select suitable pipe size for below operating conditions ofdry saturated steam (20 marks) Steam flow 25,000 kg/h Upstream pressure 14 barg Downstream pressure 13.2 barg Straight pipe length 360 m Pipe equivalence for valves and fittings 25%
Page 2 of 3
Use equation
What is the actual pressure drop through pipe when carrying 25,000kg/h of steam?
4. Write the main groups (categories) of steam traps based onthe operation? What is the basis of design of each type? (12 marks)
5. For each steam trap type, mention suitable location inprocess steam plant and clearly justify your answer in brief. (12 marks)
6. “A steam trap should not be used as a condensate pump to pumpcondensate to higher elevations”. Do you agree? Briefly justify your answer (10marks)
7. As an energy Manager in a factory you are supposed to take adecision on replacing the existing boiler with a new boiler of 85% efficiency. Thecost of new boiler is Rs. 5 million. The following information is available related to the existingboiler. . Average steam generation : 6,000 kg/hr Fuel used : furnace oil Enthalpy gained by the steam in the boiler : 610 kcal/kg ofsteam Cost of furnace oil : Rs. 100/ kg Gross calorific value of the fuel : 10,000 kcal/kg Annual operating hours : 6,500 h Boiler efficiency : 80%
Evaluate the given information and indicate your decision withreasons. (10 marks)
Where: PDF = Pressure Drop Factor (Ref: Table 10.2.6 for pipeselection) F1 = Pressure factor at inlet pressure (Ref: Table10.2.5) F2 = Pressure factor at pressure at a distance of L meters (Ref:Table 10.2.5) L = Equivalent length of pipe (m)
8. Distinguish between topping cycle and bottoming cycle inco-generation plant and give two examples for a specific industry. (3 marks)
9. There are four main sizing methods of the co-generationplants. Briefly explain each. (6 marks)
Draw a diagram for this process and find, a. Liquid enthalpy before flashing b. Liquid enthalpy after flashing c. Enthalpy of evaporation of flash steam d. Flash steam rate in kg/h
2. Select the suitable pipe sizes for 3 barg, 5 barg, 6 barg, 10barg and 14 barg for dry saturated steam through long steam pipes which carries 2000 kg/h.What is the pipe selection criteria in this case? (Refer to Table 10.2.4) (12marks)
3. Select suitable pipe size for below operating conditions ofdry saturated steam (20 marks) Steam flow 25,000 kg/h Upstream pressure 14 barg Downstream pressure 13.2 barg Straight pipe length 360 m Pipe equivalence for valves and fittings 25%
Page 2 of 3
Use equation
What is the actual pressure drop through pipe when carrying 25,000kg/h of steam?
4. Write the main groups (categories) of steam traps based onthe operation? What is the basis of design of each type? (12 marks)
5. For each steam trap type, mention suitable location inprocess steam plant and clearly justify your answer in brief. (12 marks)
6. “A steam trap should not be used as a condensate pump to pumpcondensate to higher elevations”. Do you agree? Briefly justify your answer (10marks)
7. As an energy Manager in a factory you are supposed to take adecision on replacing the existing boiler with a new boiler of 85% efficiency. Thecost of new boiler is Rs. 5 million. The following information is available related to the existingboiler. . Average steam generation : 6,000 kg/hr Fuel used : furnace oil Enthalpy gained by the steam in the boiler : 610 kcal/kg ofsteam Cost of furnace oil : Rs. 100/ kg Gross calorific value of the fuel : 10,000 kcal/kg Annual operating hours : 6,500 h Boiler efficiency : 80%
Evaluate the given information and indicate your decision withreasons. (10 marks)
Where: PDF = Pressure Drop Factor (Ref: Table 10.2.6 for pipeselection) F1 = Pressure factor at inlet pressure (Ref: Table10.2.5) F2 = Pressure factor at pressure at a distance of L meters (Ref:Table 10.2.5) L = Equivalent length of pipe (m)
8. Distinguish between topping cycle and bottoming cycle inco-generation plant and give two examples for a specific industry. (3 marks)
9. There are four main sizing methods of the co-generationplants. Briefly explain each. (6 marks)