Chapter 5, Problem 5.32P

Steam is supplied to a two-stage turbine at 40 bar and 350°C. It expands in the first turbine until it is just dry saturated, then it is re-heated to 350°C and expanded through the second-stage turbine. The condenser pressure is 0.035 bar. Calculate the work output and the heat supplied per kilogram of steam for the plant, assuming ideal processes and neglecting the feed-pump term. Calculate also the specific steam consumption and the cycle efficiency,

Calculate the amount of heat to be supplied to generate 10 kg/sec of steam at 12 MPa and 400°C from water at 115°C.

with all formulas please

In a refrigerator the power rating impressed on the compressor is 1.2 kW. The circulating wire in evaporator is 5 kW and the cooling water took away 10 kW from condenser coil. The operating temperatures range is 18ºC and 0ºC and their corresponding latent heats are 170 kJ/kg and 230 kJ/kg and the difference between theliquid energy is 35 kJ/kg. Find the actual COP of the system (2) relative COP, assuming the vapor is just dry and saturated at the end of the compression.

A steam turbine operates receiving steam from the boiler at 2000 psia and 1000 F. The steam expands to 600 psia where there is an extraction port. The temperature of the extracted steam is 750 F. 25% of the entering steam flow is extracted and sent to a feedwater heater. The remaining steam inside the turbine expands to 1.0 psia, the condenser pressure. The quality of the steam exiting the turbine to the condenser is 85%. Calculate the isentropic efficiency of the turbine. Answers:   73%   78%   64%   68%   85%

A reversible heat pump is working between 9°C and 28°C. The minimum power required per ton on heating effect is W.

The steam rate to a turbine for variable output is controlled by a throttle valve in the inlet line.Steam is supplied to the throttle valve at 1,700 kPa and 225°C. During a test run, the pressure atthe turbine inlet is 1000 kPa, the exhaust steam at 10 kPa has a quality of 0.95, the steam flowrate is 0.5 kg/s, and the power output of the turbine is 180kW. 1. What are the heat losses from the turbine? 2. What would be the power output if the steam supplied to the throttle valve were expandedisentropically to the final pressure?

Muhammad is a Mechanical Engineering major at UCR, and his team just got their butts kicked by an ME team from CSUN in a design competition. The CSUN team had a great power cycle, and one of their members (Arman) was laughing at them the entire time. When Muhammad returns to UCR he goes straight to the lab and begins working on a better power cycle design. Muhammad's power cycle takes air that is initially at a pressure of 240 kPa and a volume of 4 m³. In the first step, the air undergoes isothermal expansion to a volume of 12 m. In the second step, the air undergoes isobaric expansion to a volume of 20 m². In the third step, the air undergoes isochoric pressurization back to 240 kPa. In the fourth, and final, step the air undergoes isobaric contraction to a volume of 4 m³. What is the net heat flow, per cycle, in Muhammad’s power cycle? [Hint: Draw a PV diagram of the process. It will help.]

A gas turbine draws in air from atmosphere at 1 bar and 150C and compresses it to 4.5 bar. The air is heated to 1100 K at constant pressure and then expanded through two stages in series back to 1 bar. The high pressure turbine is connected to the compressor and produces just enough power to drive it. The low pressure stage is connected to an external load and produces 100 kW of power. For the compressor y= 1.4 and for the turbines y = 1.3. The gas constant is 0.287 kJ/kg K for both. Neglect the increase in mass due to the addition of fuel for burning. Assume the specific heat of the gas in the combustion chamber is the same as that for the turbines. Calculate the following. i. The specific heat Cp of the air and the burned mixture. (1.005 and 1.243) ii. The mass flow of air. (0.407 kg/s) 111. The inter-stage pressure of the turbines. (2.67 bar) iv. The thermal efficiency of the cycle. (30%)