Chapter 5, Problem 5.24P

2. At a particular location in the ocean, the temperature near the surface is 30°C, and the temperature at a depth of 500 m is 7.5°C. A power plant, is built based on Rankine cycle using ammonia as the working fluid, has been proposed to utilize this naturally occurring temperature gradient to produce electrical power. The power to be developed by the turbine is 240 MW. For simplicity purpose, assume the specific heat of seawater to be a constant at 4.18 kJ/kg°C. The following conditions in the Rankine cycle are given: State 1: Saturated vapour of ammonia at 24°C State 2: Saturated liquid-vapour mixture of ammonia at 10°C State 3: Saturated liquid of ammonia at 10°C State 4: Compressed liquid of ammonia (same pressure as State 1) (a) Draw a T- s diagram for the Rankine cycle with state points legibly marked on it. (b) Calculate the thermal efficiency of the proposed cycle. (c) Calculate the net power output of the plant in MW, if the pumps (pump A and pump B) used to circulate seawater…

Consider a heat engine undergoing a power cycle. a. What is the maximum thermal efficiency that an ideal heat engine can achieve ifit operates between thermal reservoirs at 1000K and 300K? b. What is the maximum possible power output from the heat engine if operating between the same two temperatures of part (a) and the heat transfer rate in to the cycle is 140 MW?

A new parabolic dish solar concentrator is being developed to supply electricity to a small remote community. The system operates with a Stirling engine connected to two heat reservoirs HR₁ and HR₂ as shown in Fig. Concentrated solar radiation Q˙ₛᵤₙ=200kW maintains HR₁ at constant temperature Tₕᵣ,₁=700℃, and a high performance heat sink device maintains HR₂ at temperature Tₕᵣ,₂=25℃. After some time of operation, an engineer working on the project realizes that the engine power output is performing below design specifications and only provides a power output of 120kW. After inspecting the system, they discover a contact resistance that causes the thermal communication between the two heat reservoirs and the engine to be imperfect in the sense that a finite temperature difference is required to establish heat transfer between each of the heat reservoirs and the engine.  Assuming the engine itself is internally reversible, estimate the rate of entropy generation in the engine’s…

A new parabolic dish solar concentrator is being developed to supply electricity to a small remote community. The system operates with a Stirling engine connected to two heat reservoirs HR₁ and HR₂ as shown in Fig. Concentrated solar radiation Q˙ₛᵤₙ=200kW maintains HR₁ at constant temperature Tₕᵣ,₁=700℃, and a high performance heat sink device maintains HR₂ at temperature Tₕᵣ,₂=25℃. After some time of operation, an engineer working on the project realizes that the engine power output is performing below design specifications and only provides a power output of 120kW. After inspecting the system, they discover a contact resistance that causes the thermal communication between the two heat reservoirs and the engine to be imperfect in the sense that a finite temperature difference is required to establish heat transfer between each of the heat reservoirs and the engine.  Sketch the cycle on a T-s diagram and include the temperatures of the heat reservoirs in your sketch. Calculate the…

A cyclic heat engine operates between a source and sink that are respectively attemperatures of 1000 0C and 50 0C. Draw the diagram, calculate the efficiency of the heatengine and the rate of heat rejection per kW net output of the engine.

See attached image. Please show clear solutions.

2. Between 300K and 600K is the operating temperature of a pair of heat pumps connected in series. The efficiency of the second heat pump is three times that of the first. Find the input work for the first and second heat pumps if the second heat pump absorbs 20kW of heat and the heat release in the first heat pump is the same.

The thermal efficiency of a Carnot heat engine is 30%. If the engine is reversed in operation to work as a heat pump with same operating conditions then what will be the COP for heat pump? (B) 2.33 (D) Can't be calculate (A) 0.30 (C) 3.33

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