The difference between 80 percent efficiency furnaces and 90 percent efficiency furnaces is that 90 percent efficiency furnaces:
A) Use more combustion air per 1,000 BTU firing rate.
B) Have an extra recuperative heat exchanger that condenses water out of the flue gas.
C) Burn more gas to increase the heat exchanger temperatures.
D) Use more efficient air filters.
B
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A distillation unit is to be used to generate pure water vapor. 2.0 kg/s of liquid water at 25oC enters the system, and 0.2 kg/s of saturated water vapor leaves through one port and 1.8 kg/s of saturated liquid leaves through a second port (along with impurities in the water which can be neglected in the analysis). The pressure throughout the whole system is 100 kPa. There is no work done in the process, and all energy is added through heat transfer. (a) Determine the rate of heat transfer needed to produce this flow of saturated water vapor. (b) Using your separation chamber model, plot the heat transfer rates needed to produce saturated water vapor flow rates between 0.1 kg/s and 1.0 kg/s (along with corresponding changes to the saturated liquid water exit flow rates).
State 1: Inlet stream; State 2: Saturated vapor exit stream; State 3: Saturated liquid exit. Given: P1 = P2 = P3 = 100 kPa; T1 = 20oC; x2 = 1.0; x3 = 0.0; m?1=2.0kgs; m?2=0.2kgs; m?3=1.80kgs Assume: W?=0 (given). Given no other information regarding the mixing chamber, make the following common assumptions: ?KE=?PE=0. We are told there is heat transfer. Also, assume the mixing chamber is a single-inlet, multiple-outlet, steady-state, steady-flow device. What will be an ideal response?
Which of the following is NOT a type of torque wrench?
A. electronic B. click C. spring D. dial
The same set of principles are used when reading and setting metric vernier calipers as for customary vernier calipers.
Answer the following statement true (T) or false (F)
Technician A says "intent to vent" means the technician is working in a shop without adequate ventilation. Technician B says "intent to vent" means the technician is working on an air conditioner in a shop that does not have a recovery machine for each type of refrigerant being serviced. Who is correct?
A. Technician A only B. Technician B only C. Both A and B D. Neither A nor B