Question

In: Other

When a chemical plant needs steam at multiple pressure levels, it is often economical to generate...

When a chemical plant needs steam at multiple pressure levels, it is often economical to generate all the steam at a high pressure and then to let the steam down through pressure-reducing turbines to the desired pressure. This principle is illustrated in Figure 8.6. The downside of this approach is that as the exhaust pressure of the turbine increases, the theoretical (and actual) steam requirements increase, meaning that less energy is extracted. To illustrate this point, do the following:

a. Estimate the amount of energy extracted from 10,000 kg/h of 58.6 barg steam superheated by 165°C when connected to the following turbines (each 80% efficient):

i. Exhaust pressure is 4″ Hg absolute.

ii. Exhaust pressure is 4.82 barg.

b. Estimate the amount of energy extracted from 10,000 kg/h of saturated, 10.0 barg steam when connected to a turbine (80% efficient) exhausting at 4.82 barg.

c. Identify the locations of each of the three turbines described above on Figure 8.6.

From the book "Perrys Chemical Engineers", 6th ed Figure 8.5 and 8.6

Solutions

Expert Solution


Related Solutions

Steam enters the high-pressure turbine of a steam power plant that operates on the ideal reheat...
Steam enters the high-pressure turbine of a steam power plant that operates on the ideal reheat Rankine cycle at 6 MPa and 500°C and leaves as saturated vapor. Steam is then reheated to 400°C before it expands to a pressure of 10 kPa. Heat is transferred to the steam in the boiler at a rate of 6*104 kW. Steam is cooled in the condenser by the cooling water from a nearby river, which enters the condenser at 7°C. Show the...
In a process plant, a large amount of saturated steam is available at a pressure of...
In a process plant, a large amount of saturated steam is available at a pressure of 2 MPa. Connected to the saturated steam system through a valve is a turbine followed by a well insulated tank which is initially evacuated (P=0). The volume of the tank is 2000 L. When emergency power is needed, the valve is opened and steam flows through the turbine, generating power and the tank fills until its pressure is 2 MPa. At the end of...
Consider a steam power plant operating on the ideal reheat Rankine cycle. Steam enters the high-pressure...
Consider a steam power plant operating on the ideal reheat Rankine cycle. Steam enters the high-pressure turbine at PH MPa and TH °C and is condensed in the condenser at a pressure of PL kPa. Assume the steam is reheated to the inlet temperature of the high-pressure turbine, and that pump work is NOT negligible. If the moisture content of the steam at the exit of the low-pressure turbine is not to exceed w% percent, determine: (a) the pressure at...
A steam power plant operates with a maximum pressure of 3500 psia and maximum temperature of...
A steam power plant operates with a maximum pressure of 3500 psia and maximum temperature of 1050 oF. Assume a simple Rankine cycle, condenser pressure is 10 psia, and turbomachinery is isentropic. Turbine work in Btu/lb Pump work in Btu/lb Heat addition in steam generator in Btu/lb Cycle thermal efficiency
The net power of a combined gas-steam power plant is 450 MW. The pressure ratio of...
The net power of a combined gas-steam power plant is 450 MW. The pressure ratio of the gas turbine cycle is 14, the air enters the compressor at a temperature of 300 K and the turbine at a temperature of 1400 K. Combustion end gases coming out of the gas turbine produce steam at a waste heat boiler at 8 MPa pressure and 400 degrees Celsius temperature and exit the boiler at 460 K temperature. The steam cycle has an...
Three return steam lines in a chemical processing plant enter a collection tank operating at steady...
Three return steam lines in a chemical processing plant enter a collection tank operating at steady state at 5 bar. Steam enters inlet 1 with flow rate of 2 kg/s and quality of 0.9. Steam enters inlet 2 with flow rate of 2 kg/s at 200°C. Steam enters inlet 3 with flow rate of 1.2 kg/s at 95°C. Steam exits the tank at 5 bar. The rate of heat transfer from the collection tank is 40 kW. Neglecting kinetic and...
Superheated steam at 20 MPa, 640°C enters the turbine of a vapor power plant. The pressure...
Superheated steam at 20 MPa, 640°C enters the turbine of a vapor power plant. The pressure at the exit of the turbine is 0.5 bar, and liquid leaves the condenser at 0.4 bar at 75°C. The pressure is increased to 20.1 MPa across the pump. The turbine and pump have isentropic efficiencies of 81 and 85%, respectively. Cooling water enters the condenser at 20°C with a mass flow rate of 70.7 kg/s and exits the condenser at 38°C. For the...
The Clap Chemical Company needs a large insulated stainless steel tank to expand its plant. A...
The Clap Chemical Company needs a large insulated stainless steel tank to expand its plant. A recently closed brewery has offered to sell their tank for $15,000 delivered. The price is so low that Clap believes it can sell the tank at any future time and recover its $15,000 investment. Installing the tank will cost $9000 and removing it will cost $5000. The outside of the tank is covered with heavy insulation that requires considerable maintenance. This will cost $3500...
Question Set 3. A small manufacturing plant produces specialized stainless steel valves for high-pressure steam systems....
Question Set 3. A small manufacturing plant produces specialized stainless steel valves for high-pressure steam systems. Each valve costs $2000 to produce. The plant incurs $1,200,000 in fixed annual costs. The plant sells the valves directly to power plants for $6400 each. For this question set, use the following formulas: [Total Profit] = [Total Revenue] – [Total Cost] [Total Revenue] = [Production] x [Unit Revenue] [Total Cost] = [Production] x [Variable Unit Cost] + [Fixed Costs] 1. Create a data...
When there is no clear correct behavior, people often feel pressure to imitate the behavior of...
When there is no clear correct behavior, people often feel pressure to imitate the behavior of those around them. This demonstrates the power of: unanimity. observation. public responses. ambiguity. 2. The _____ study was conducted to determine if group size influenced conformity. Gawkers Line Autokinetic Social conformity 3. _____ is a researcher of social influence who took advantage of the autokinetic phenomenon. Solomon Asch Karen Horney Abraham Maslow Muzafer Sherif 4. Which is NOT a condition increasing the likelihood of...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT