Example 3.4 Checking if Dry or Wet Compression is Desirable in Ammonia Systems An ammonia refrigerating machine has working temperatures of 35°C in the condenser and -15°C in the evaporator. Assume two cases; (a) dry compression, and (b) wet compression Calculate for each, the following; (i) the theoretical piston displacement per ton refrigeration, (ii) the theoretical horsepower per ton refrigeration, and (iii) the coefficient of performance.

Example 3.4 Checking if Dry or Wet Compression is Desirable in Ammonia Systems An ammonia refrigerating machine has working temperatures of 35°C in the condenser and -15°C in the evaporator. Assume two cases; (a) dry compression, and (b) wet compression Calculate for each, the following; (i) the theoretical piston displacement per ton refrigeration, (ii) the theoretical horsepower per ton refrigeration, and (iii) the coefficient of performance.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter6: Forced Convection Over Exterior Surfaces

Section: Chapter Questions

Problem 6.51P

See similar textbooks

Similar questions

The condensing pressure for a Rankine engine is 0.001325 MPavac. Calculate the following for steam flow rate = 16.3846 kg/sec of steam when the steam at the beginning of expansion is at 119.6 deg SH and 4.0 Mpaa. Draw the TS and equipment diagrams for the ideal and actual case and find for the following for the ideal case: Combined work (KW) . Ans.____________________________ Combined steam rate in kg/KW-hr. Ans.___________________________ Actual heat rate( KJ/KW-hr). Ans.____________________________
Consider a cylinder of a gasoline engine at the beginning of the compression cycle, duringwhich a fuel/air mixture (for our purposes mostly composed of nitrogen and oxygen, i.e.an ideal gas of diatomic molecules) at 300 K and 1 bar is compressed down to one-tenthvolume (compression ratio of 10:1). Assume that the compression is rapid so no heatexchange occurs with the environment. Calculate the pressure and the temperature ofthe compressed gas. In a diesel engine, the compression ratios are typically much higher;redo the same calculation with a compression ratio of 20:1.
In this task, you are suggesting a suitable design for a compressor to be used for gas power plant. You client has asked you to suggest a design for a compressor, where air is compressed from 100 kPa and 30℃ to 10 bar. Prepare a technical design report using following criteria in your design To optimise the final temperature of the gas, you are asked to use various polytrophic compression process. Calculate the final temperature when the process is: Isothermal, Polytropically (n=1.2), Adiabatically Polytropically (n=1.6). Comment on your findings and recommend appropriate process for compression by calculating work input.
Pls. Answer... A steam engine boiler is maintained at 250°C and water is converted into steam. This steam is used to do work and heat is ejected to the surrounding air at temperature 300K. Calculate the maximum efficiency it can have in percent?
Round eveything to 4 decimal places. Saturated steam at 150°C is used as a working fluid for a device that supplies heat to a reservoir with a temperature of 250°C. Since the device is not 100% efficient, waste heat is produced to a sink of cooling water at 10°C. To be able to maintain the temperature in the reservoir, 2500 kJ of heat should be supplied, is this possible? Prove using entropy. Assume that the working fluid leaves as liquid water at 15°C.
ANSWER SHOULD BE: 258 kW, 143 kWPLEASE SHOW THE STEP-BY-STEP SOLUTION
can you please solve this for me (the fraction of steam extracted from theturbine for the open feedwater heater)
Draw a VLLE diagram when the temperature is constant.
Provide a complete given and computation. Include all the decimals. There are received 68,000 kg/h of steam by an ideal regenerated engine, having only one heater, of which the heater receives 15,400 kg/hr the condenser receives the remainder at 0.007 MPa. If the heater pressure is 0.96 MPa, find the state (quality or "SH) of the steam (a) at the heater entrance and (b) at the condenser entrance.
The condensing pressure for a Rankine engine is 0.001325 MPavac. Calculate the following for steam flow rate = 1 kg/sec of steam when the steam at the beginning of expansion is at 119.6 deg SH and 4.0 Mpaa. Draw the TS and equipment diagrams for the ideal and actual case and find for the following for the ideal case: Ideal turbine work (KW). Ans.____________________________ Heat rejected at condenser (KJ/sec). Ans.____________________________ Mass of cooling water in kg/sec if cp H2O = 4.18 KJ/kg-K, and inlet temp of water to condenser = 20 deg C, outlet temp is 35 deg C. Ans.____________________________ Pump work in KW. Ans.___________________________
Liquid water at 35 ºF is fed to a boiler operating at 10 bars and is converted at constant pressureto saturated steam. The steam is produced at a steady state flow rate of 600 lbm/hr. Assume thatthe kinetic energy of the liquid entering the boiler is negligible, and that the steam is dischargedfrom the boiler through a 1 ft pipe.a. Calculate ∆Ĥ (in units of Btu/lbm) for this process.b. Calculate the heat input (Btu/hr) to meet the needed saturated steam production rate.
A boiler plant raises 5.2 kg/s of steam at 1825 kN/m² pressure, using coal of calorific value 27.2 MJ/kg. If the boiler efficiency is 75%, how much coal is consumed per day? If the steam is used to generate electricity, what is the power generation in kilowatts assuming a 20% conversion efficiency of the turbines and generators?