Refrigerant R-134a at 1.2 MPa and 120 °C is throttled through a valve to 280 kPa. Assume no change in kinetic and potential energies. What is the exit temperature (in °C)? Select one: O 108.13 O 111.43 122.15 O 100.61 O 89.66 O 117.23

It is planned to build a geothermal power plant for electricity generation purposes. The subsoil water reaches temperatures close to 170 ° C while the ambient temperature is 20 ° C. Find the maximum efficiency that a geothermal plant could aspire to if installed in that location.   Ans: η=33.85%

Ger Chose The Correct Answer The equation of work done in a reversible process for a closed sysfem can be expressed as: W12 = S, PdP on %3D W12 = S, PdV W12 = , VdP W12 = S, Vav Next page ot=802467&cmid 151230 hp

Draw a Temperature (T) versus Entropy (s) diagram for a typical gas turbine. Thediagram should show the processes for an actual gas turbine and should show theeffect of real world losses where the compressor and turbine have an isentropicefficiency and pressure losses in the combustion chamber in an actual gas turbine.Explain each of the processes on the T-s diagram.

A two stage compressor is used to compress 800 m3 /h of CO2 measured at 288K and 1 bar from its initial state of 0.5bar and 30k to a pressure of 1.5 bar with inter cooling to 300K. A compression efficiency of 85% may be assumed in each stage. Calculate the power required to run the compressor and the discharge temperature.

13. 1.2 kg gas (R = 260 J/kg K, k = 1.395) in a Tank is stirred by a naddle until the pressure is doubled. The change in entropy is, Saved successfully C-0.568 a 0.531 b 0.547 d-0.547

Determine the amount of work required to compressed 1.5 kg of air at a pressure of 7 barg. The isentropic index is 1.2 and the air intake is at 1 bar, 200C & RH =65% v)  The discharged air is passed through an R134a refrigerant dryer, the temperature of air coming out the dryer is 400C. The air then settles inside a reservoir at a temperature of 25 0C. Determine: The humidity variation throughout the production of compressed air The amount of condensate formed at each stage of the process by using The humidity definition

Do it fast

2) Argon (ideal gas, Cp=0.5203 kJ/kg.K) at 27 ºC, 85 kPa, and 215 m/s enters a diffuser at a rate of 2 kg/s and leaves at 50 ºC. The exit area of the diffuser is 500 cm2. The gas is estimated to lose heat at a rate of 20 kJ/s during this process.  Required: Draw a standard and clear schematic of the problem and label the performance of the schematic. Perform step by step energy and mass analyses, state your assumptions and determine the following:a) The exit velocityb) The inlet areac) The inlet pressure of the Argon

According to Newton’s law of cooling, the rate of change of temperature is proportional to the temperature difference between the system and its surroundings:dT/dt= -α(T-Tsur)where Tsur is the temperature of the surroundings and α is a constant. (a) Integrate this equation with the initial condition that T = Ti at t = 0.(b) Given that the entropy varies with temperature according to S(T) − S(Ti) = C ln(T/Ti), where Ti is the initial temperature and C the heat capacity, deduce an expression entropy of the system at time t.