A 4-cylinder ammonia compressor with a bore 0.04 m & stroke 0.03 m running 2500. The system operates in a simple VCC with evaporating & condensing temperatures zero C & 40 C, respectively generating cooling capacity 5 tons.
Determine:
a. Draw the PH diagram indicating all enthalpies & sp. vol.
b. Piston displacement, m3/sec
c. Suction Volume, m3/sec
d. Volumetric efficiency
e. Mass of refrigerant, kg/sec
f. Work of compressor, kW

Machine A was purchased three years ago for $23,000 and had an estimated MV of $2,300 at the end of its 10-year life. Annual operating costs are $2,300. The machine will perform satisfactorily for the next seven years. A salesperson for another company is offering Machine B for $57,000 with an MV of $5,500 after 10 years. Annual operating costs will be $1,500. Machine A could be sold now for $17,000, and MARR is 15% per year. Compare the before-tax equivalent uniform annual cost, EUAC, of the defender (keeping Machine A) to the challenger (buying Machine B). To answer this problem, calculate the value of the difference in annual costs; EUAC(challenger) – EUAC(defender) = EUAC(Machine B) – EUAC(Machine A). (Enter your answer as a number without the dollar $ sign.)

Why does not baitite occur in the continuous cooling transformation diagram?

Think about a turboprop engine (explained in the lecture). The turbine-compressor assembly drives a propeller for the propulsion and it delivers net power of 1.1 MW to the prop. This aircraft was designed to fly at 8km altitude with 550 km/h speed. The atmospheric condition up there is 236K and 0.36 bar. Air enters the diffuser and decelerates to 0 km/h for maximizing the ram effect. The compression ratio is 6.3 and the isentropic efficiency of the compressor is 83%. The turbine has 1360K inlet temperature, and the efficiency is also 83%. The pressure at the turbine exit is 10 kPa higher than the ambient pressure, and assume that the diffuser and nozzle show isentropic behaviors. Kinetic energy except for at the diffuser and the nozzle exit can be neglected. Determine:

a) The mass flow rate in kg/s.

b) The volumetric flow rate in m³/s.

c) The heat rate produced in the combustion in W.

d) The gas velocity leaves the nozzle in m/s.

a. With the aid of appropriate sketches and thermodynamic analysis, describe the stages
of a typical Carnot cycle
b. 0.82 kg of air (ideal gas) executes a Carnot power cycle having a thermal efficiency of 34 percent. The heat transfer to the air during the isothermal expansion is 82 kJ. At the

4) A refrigerator in the kitchen at 30 ° C keeps the food section at -12 ° C. Refrigerant R-134a enters the evaporator located at the back of the freezer section of a home refrigerator with a degree of dryness of 100 kPa and 20 percent and exits at 100 kPa and -20 ° C. Since the compressor consumes 600 W and the COP of the refrigerator is 2.5, a) calculate the minimum flow (kW) required to keep the mass flow of the refrigerant, b) the heat released into the kitchen air (kW), c) the food section at -12 ° C. (20 point)

3) Air enters a compressor at 2 m / s, 20 ° C and 100 kPa pressure, exits at 50 m / s, 900 kPa pressure and 200 ° C. Make sure that the power consumed by the compressor is 500 kW. The outlet cross-section diameter of the compressor is 10 cm. (Neglect the change in potential energy.) (15 points)

CALCULATE THE AMOUNT OF HEAT?

Define the following terms,
(i) specific work transfer
(ii) specific air consumption
(iii) work ratio
(iv) swept volume
b. DerivetheformulaforthemeaneffectivepressureoftheOttocycle
c. An engine of 200 mm bore and 315 mm stroke works on Otto Cycle. The clearance is
3O
0.00251 m . The initial pressure and temperature are 1 bar and 65 C. If the maximum
pressure is limited to 35 bar, calculate the following,
(i) The air standard efficiency of the cycle
(ii) The mean effective pressure for the cycle

A power station uses Diesel as fuel (C12H26), from the analysis of combustion gases, it's obtain that 30% of carbon is converted to CO and the rest to CO2.

Furthermore, the gases in the exhaust have a temperature of 450 K. with this information:

a) mass air-fuel ratio: In Kgair/Kgfuel

b) Theoric air percentage: %

c) Moles of water steam produced in the reaction: in kmol

d)"wasted" heat in the gases on the steam exhaust, if you consider that the ideal exit temprature of the combustion gases should be of 380K: in kJ/kg

i need summary between (4-10) pages about ((Control circuit refrigeration system in airplanes)) with name of the references in end page

Two equal gear wheel of 360 mm p.c.d and 6 module are in mesh if the pressure angle 20 determine the maximum addendum necessary if there are always to be at least two pairs of teeth in contact . if the gear wheels rorates at 110 r.p.m and 6 kw is being transmetted find the normal force between the teeth assuming that the total force is dividing equally between the two pairs of teeth Neglect the frection. (Ans 6.8mm , 1.54KN .)

Briefly describe (with the use of diagrams) the Brayton’s cycle and derive the formula for
the coefficient of performance for the Brayton’s cycl

A house that is losing heat to the 100C outdoors at an average rate of 50,000 kJ/h is maintained at 220C at all
times during a winter night for 10 h. The house is to be heated by 50 glass containers each containing 20 L
(1L=10-3 m3
) of water that is heated to 80oC during the day by a solar heater. A thermostat-controlled 15-kW
back-up electric resistance heater turns on whenever necessary to keep the house at 220C. Analyse and
determine the following:
i. If the average solar intensity is 650 W/m2

and the solar heater has an efficiency of 80%, calculate the

area of solar heater to heat 20L of water from 220C to 800C in 8 hours.
ii. How long did the electric heating system run at night?
iii. Keeping 2nd law of thermodynamics in mind, what is the maximum efficiency of the back-up heater?
iv. If the heat provided by the back-up heater is provided using Carnot heat pump, determine the
reduction in electricity consumption.

Derive the general energy equation for the following systems using appropriate diagrams,
(i) Internal combustion engine
(ii) Steam turbine
(iii) Boiler
(iv) Compressor

A machine is out of order for minor work. Define controls
exercised in maintenance. Department required for its maintenance.