Question

In: Other

A particular power plant operates with a heat-source reservoir at 350°C and a heat-sink reservoir at...

A particular power plant operates with a heat-source reservoir at 350°C and a heat-sink reservoir at 30°C. It has a thermal efficiency equal to 67% of the Carnot-engine thermal efficiency for the same temperatures.

What is the thermal efficiency of the plant?

The thermal efficiency of the plant is .

Expert Solution

Particular power plant operates with heat source reservoir Temperature Th = 350 C = 350 + 273 = 623 K

Heat sink reservoir temperature TL = 30 C = 30 + 273 = 303K

Carnot engine cycle - Carnot engine gives maximum efficiency. It is based on second law of thermodynamics. Carnot engine is used to transfer heat from higher to lower temperature by converting some amount of work. By second law of thermodynamics heat can not be fully converted into work.

If we give heat from heat reservoir source is Qh and engine transfer to the sink reservoir QL by converting W work then,

Carnot engine efficiency = work output /heat input = W/Qh

Where W = Qh - QL

By entropy relation, Qh = Th*ΔS

QL = TL*ΔS

Efficiency = Qh-QL/Qh = 1- QL/Qh = 1- TL*ΔS/Th*ΔS = 1- TL/Th

Carnot engine efficiency = (1- TL/Th)*100

= (1-303/623)*100 = 51.36 %

Given power plant operates with thermal efficiency equal to 67% of carnot engine efficiency.

power plant thermal efficiency = 0.67*51.36 = 34.41%

Ans: 34.41 %

Amanda K answered 7 months ago

A steam power plant operates with a boiler that is heated from a heat source at...

A steam power plant operates with a boiler that is heated from a heat source at 457 °C and produces 450 ton/hr. of steam. The steam leaves the boiler at 425 °C and 4 MPa. The steam reaches a turbine at 375 °C and 3 MPa and leaves it at 50 kPa with 4% liquid water. This mixture is flown into a condenser that rejects the heat into a river at 17 °C. Water leaves the condenser at 50 kPa...

A heat engine operates between a source and a sink. The source temperatures vary from 300...

A heat engine operates between a source and a sink. The source temperatures vary from 300 to 1000°C. Heat is supplied to the heat engine at a steady rate of 1200 kJ/min. Using Matlab or Excel (or other) software, study the effects of the temperatures of the heat source and the heat sink on the maximum power produced and the cycle thermal efficiency. Plot the power produced and the cycle efficiency against the source temperature for sink temperatures of 0°C,...

A binary geothermal power plant uses geothermal water at 160°C as the heat source. The plant...

A binary geothermal power plant uses geothermal water at 160°C as the heat source. The plant operates on the simple Rankine cycle with isobutane as the working fluid. Heat is transferred to the cycle by a heat exchanger in which geothermal liquid water enters at 160°C at a rate of 555.9 kg/s and leaves at 90°C. Isobutane enters the turbine at 3.25 MPa and 147°C and leaves at 79.5°C and 410 kPa. Isobutane is condensed in an air-cooled condenser and...

19 - 3 -4 A heat engine operates between a reservoir at 29°C and one at...

19 - 3 -4 A heat engine operates between a reservoir at 29°C and one at 341°C. What is the maximum efficiency possible for this engine? heat engine operates in a Carnot cycle between 88.0°C and 345°C. It absorbs 21,200 J of energy per cycle from the hot reservoir. The duration of each cycle is 3.00 s. (a) What is the mechanical power output of this engine? kW (b) How much energy does it expel in each cycle by heat?

A heat engine operates between a high-temperature reservoir at 610 K and a low-temperature reservoir at...

A heat engine operates between a high-temperature reservoir at 610 K and a low-temperature reservoir at 320 K. In one cycle, the engine absorbs 6800 J of heat from the high-temperature reservoir and does 2200 J of work. A) What is the net change in entropy as a result of this cycle?

1. A nuclear power plant contains a heat engine that operates between the temperatures of 150oC...

1. A nuclear power plant contains a heat engine that operates between the temperatures of 150oC and 677oC. (a) What is the Carnot efficiency of the engine? (b) If the engine exhausts energy to the cold reservoir at a rate of QC = 7.0 × 108 J per second, how much heat energy must be flowing into the engine from the hot reservoir (QH) each second? 2. A house has a flat (horizontal) roof. If the wind then blows over...

A heat engine operates by extracting 2,000 KJ of heat from a source at 1500 K,...

A heat engine operates by extracting 2,000 KJ of heat from a source at 1500 K, and dumping 800 of waste heat into a sink at 300 K. a) Does this engine violate any known laws of thermodynamics? b) How much work does this engine produce? c) What are the first and second law efficiencies?

A heat engine operates between two reservoirs at T2 = 600 K and T1 = 350...

A heat engine operates between two reservoirs at T2 = 600 K and T1 = 350 K. It takes in 1 000 J of energy from the higher-temperature reservoir and performs 250 J of work. Find (a) the entropy change of the Universe delta SU for this process and (b) the work W that could have been done by an ideal Carnot engine operating between these two reservoirs. (c) Show that the difference between the amounts of work done in...

A power company operates three power generation plants. One is a wind plant, and the other...

A power company operates three power generation plants. One is a wind plant, and the other two consume a combination of Fuel 1 and Fuel 2, emitting carbon dioxide in the process. In addition, all three plants require maintenance. The amount of fuel consumed (in Mg), maintenance required (in person-hours), carbon dioxide (CO2) emitted (in Mg), and power generated (in MWh) per day of operation is as follows: Maintenance Fuel 1 Fuel 2 CO2 Power Plant Required Required Required Emitted...

A steam power plant receives heat from a furnace at a rate of 280 GJ/h. Heat...

A steam power plant receives heat from a furnace at a rate of 280 GJ/h. Heat losses to the surrounding air from the steam as it passes through the pipes and other components are estimated to be about 8 GJ/h. If the waste heat is transferred to the cooling water at a rate of 145 GJ/h, determine (a) net power output and (b) the thermal efficiency of this power plant