Which of the following statements are true regarding throttling valves?Group of answer choicesThrottle valves are flow restricting devices that cause a pressure drop in a fluid.The pressure drops across a throttle valve is often accompanied by a large increase in temperature.The flow through a throttle valve may be assumed to be adiabatic.Since pressure drops across a throttle valve, work cannot be neglected.For a single stream, steady flow throttle valve, the inlet and outlet enthalpies can be approximated to be the same.

A throttling valve is used in the ideal refrigeration cycle because ____________Question 5Select one:a.it is impossible to expand a liquid vapour mixture with a turbineb.the use of a turbine would require more work input to operatec.the use of a turbine improves the cooling power of the cycle, but would substantially increase the cost and complexityd.it provides an increase in entropy which corresponds to an additional heat input from the low temperature reservoir

Which of the following is true of regulators?Group of answer choicesAll regulators work on different principles.The regulator reduces the system pressure to the proper lower working pressure.The lower pressure must be allowed to fluctuate over a range of flow rates.All regulators can be safely interchanged for different pressure ranges.

If steam is passing through a throttling valve in a steady flow process, and we define the control volume as the valve:Question 2Select one:a.ΔmCV = 0, ΔECV = 0 and ΔSCV = 0b.ΔmCV > 0, ΔECV > 0 and ΔSCV > 0c.ΔmCV = 0, ΔECV > 0 and ΔSCV > 0d.ΔmCV = 0, ΔECV = 0 and ΔSCV > 0

If the refrigerant enters the throttling valve as a saturated liquid at 30 deg C in one cycle and as a subcooled liquid at 30 deg C in another for the same evaporator pressure in both, which cycle will have the higher COP?Question 3Select one:a.The first, since the second will involve a higher condensor pressure and require more net work for the same Qinb.The first, as will have a greater heat rejection for the same heat inputc.The second, since the fluid at the inlet to the evaporator will arrive at a lower entalhpy and be able to absorb more heat before reaching the compressord.The second, as will have a greater heat rejection for the same heat inpute.If the temperature remains the same the COP of both cycles will be the same.Clear my choiceCheckQuestion 3

n this course, we commonly assume which of the following for flow devices like pumps, heat exchanges, turbines and compressors?1 pointSteady FlowSteady StateSteady State and Steady FlowSteady State, Steady Flow, Constant Temperature