【Learn Ethylene Together】Five questions per day to easily learn about ethylene 29

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【Learn Ethylene Together】Five questions per day to easily learn about ethylene. Question 29: Multiple choice. 11. What is the correct way to deal with a decrease in the vacuum level of the unit? ( ) a. Close the outlet valve of the cooling water heat exchanger. b. Add make-up water. c. Clean the main surface condenser. 12. Possible reasons for an increase in the amount of turbine condensate. （） a. Increased water supply b. Stuck steam extraction valve c. Decreased vacuum level d. Fluctuations in the steam pipeline network. 13. The possible causes of unit vibration include . （） a、Poor alignment b、Fluctuations in the lubrication system c、Bent shaft d、Too low process flow rate. 14. The reasons for changes in pressure in the refrigeration system are . ( ) a. Fluctuations in coolant usage b. Contamination by light components c. Contamination by heavy components d. Changes in rotation speed. 15. Which of the following statements are correct regarding the three-machine system? （） a. Increasing the suction pressure can reduce the compressor’s power consumption. b. Reducing the pressure drop between stages can lower the compressor’s power consumption. c. Raising the suction temperature can decrease the compressor’s power consumption. d. Lowering the suction pressure can reduce the compressor’s power consumption. 11. What is the correct way to address a decrease in the vacuum level of the unit? bc a. Reduce the outlet valve of the cooling water heat exchanger; b. Add make-up water; c. Clean the main surface condenser. 12. Possible reasons for an increase in the amount of turbine condensate. (b, d) a. Increased water supply; b. Stuck steam extraction valve; c. Decreased vacuum level; d. Fluctuations in the steam pipeline system. 13. Possible causes of unit vibration include . (a, b, c, d) a. Poor alignment; b. Fluctuations in the lubrication system; c. Bent shaft; d. Too low process flow rate. 14. The reasons for changes in pressure in the refrigeration system are as follows. (b, c, d) a. Fluctuations in coolant usage b. Light-component contamination c. Heavy-component contamination d. Changes in rotational speed 15. Which of the following statements are correct regarding the three-machine system? (a, b) a. Increasing the suction pressure can reduce the compressor’s power consumption. b. Reducing the pressure drop between stages can lower the compressor’s power consumption. c. Raising the suction temperature can decrease the compressor’s power consumption. d. Lowering the suction pressure can reduce the compressor’s power consumption