Chapter 5, Problem 5.15CU

_____________states that when a system undergoes a thermodynamic cycle then the net heat supplied to the system from its surrounding plus the net work input to the system from its surroundings must equal zero.

Combustion engineering

An air conditioner is a device used to cool the inside of a home. It is, in essence, a refrigerator in which mechanical work is done and heat removed from the (cooler) inside and rejected to the (warmer) outside. A home air conditioner operating on a reversible Carnot cycle between the inside, absolute temperature T2, and the outside, absolute tempera- ture T1 > T2, consumes P joules/sec from the power lines when operating continuously. (a) In one second, the air conditioner absorbs Q2 joules from the house and rejects Q1 joules outdoors. Develop a formula for the efficiency ratio Q2/P in terms of T1 and T2. (b) Heat leakage into the house follows Newton's law Q = A(T, – T2). Develop a formula for T, in terms of T1, P, and A for continuous operation of the air conditioner under constant outside temperature T and uniform (in space) inside temperature T2. (c) The air conditioner is controlled by the usual on-off thermostat and it is observed that when the thermostat set at 20°C and an…

A steam power plant operates on a thermodynamic cycle in which water circulates through a boiler, turbine, condenser, pump, and back to the boiler. For each kilogram of steam (water) flowing through the cycle, the cycle receives 2100 kJ of heat in the boiler, rejects 1100 kJ of heat to the environment in the condenser, and receives 10 kJ of work in the cycle for stage one pump and another 10 kJ of work in the cycle for second stage one 1. Determine the work done by the steam in the turbine, in kJ/kg. 2. Determine the thermal efficiency for this cycle.

Steady-state operating data for a simple steam power plant are provided in the figure shown. Stray heat transfer and kinetic and potential energy effects can be ignored. Determine (a) the thermal efficiency and (b) the mass flow rate of the cooling water, in kg per kg of steam flowing.

A gas within a piston-cylinder assembly executes a Carnot power cycle during which the isothermal expansion occurs at TH = 500 K and the isothermal compression occurs at TC = 290 K.     Determine:   (a) the thermal efficiency.   (b) the percent change in thermal efficiency if TH increases by 5% while TC remains the same.   (c) the percent change in thermal efficiency if TC decreases by 5% while TH remains the same.   (d) the percent change in thermal efficiency if TH increases by 5% and TC decreases by 5%.

A gas within a piston-cylinder assembly executes a Carnot power cycle during which the isothermal expansion occurs at TH = 500 K and the isothermal compression occurs at Tc = 290 K. Determine: (a) the thermal efficiency. (b) the percent change in thermal efficiency if TH increases by 15% while Tc remains the same. (c) the percent change in thermal efficiency if Tc decreases by 15% while TH remains the same. (d) the percent change in thermal efficiency if TH increases by 15% and Tc decreases by 15%. Part A Determine the thermal efficiency. na = Save for Later % Attempts: 0 of 5 used Part B The parts of this question must be completed in order. This part will be available when you complete the part above. Part C The parts of this question must be completed in order. This part will be available when you complete the part above. Part D The parts of this question must be completed in order. This part will be available when you complete the part above. Submit Answer

The figure shows the schematic of a vapor power plant in which 100 kg/s of water circulates through the four components operating at steady state. The water flows through the boiler and condenser at constant pressure and through the turbine and pump adiabatically. Kinetic and potential energy effects can be ignored.Process data follow:Process 4–1: constant-pressure at 4000 kPa from saturated liquid to saturated vapor.Process 2–3: constant-pressure at 20 kPa from x2 = 88% to x3 = 18%.   Determine the cycle thermal efficiency.  Determine σ˙cycle, in kW/K. Determine if the cycle is internally reversible, irreversible, or impossible.

What are the types of thermodynamic cycle as to the type of output? Define each.