Chapter 8, Problem 8.42P

A water feed pump operates with a mass flow rate of 464 kg/s. The inlet pressure is 689 kPa and the outlet pressure is 26 MPa. Water enters the pump at 422 K. Assuming an isentropic efficiency of 85%, estimate the power required to drive the pump.

In a Rankine Cycle, real work required by the pump is less that the isentropic work. True False

For a Rankine cycle, decreasing minimum pressure while holding all other parameters constant will allow an engineer to make the following statements Group of answer choices The quality at the turbine exit will decrease increasing liquid water content and back stage turbine damage, Turbine net work output will increase due to the reduced pressure at the exit The quality at the turbine exit will increase improving turbine reliability The average temperature at which heat is rejected will increase increasing thermal efficiency

A steady-flow system operating on the ideal Ericsson cycle can achieve the Carnot efficiency. One of the salient features of this cycle is the isothermal expansion through a heated turbine, as shown in Fig. a. Heat is added to the turbine such that the outlet temperature is equal to the inlet temperature, i.e. T₁=T₂, and the overall pressure ratio for this process is rₚ=P₁/P₂. However, an isothermal expansion through a heated turbine is very difficult to achieve in practical engineering applications. An alternate approach is two use a multi-stage expansion process with reheating. In this approach, the gas expansion process is carried out in multiple stages with reheating in between each stage. Consider the two-stage turbine expansion with reheating shown in Fig. b. The gas enters the first stage of the turbine at state A1, is expanded isentropically to an intermediate pressure Pₐ₂, is reheated at constant pressure to state B1, and is expanded in the second stage isentropically to the…

A steady-flow system operating on the ideal Ericsson cycle can achieve the Carnot efficiency. One of the salient features of this cycle is the isothermal expansion through a heated turbine, as shown in Fig. a. Heat is added to the turbine such that the outlet temperature is equal to the inlet temperature, i.e. T₁=T₂, and the overall pressure ratio for this process is rₚ=P₁/P₂. However, an isothermal expansion through a heated turbine is very difficult to achieve in practical engineering applications. An alternate approach is two use a multi-stage expansion process with reheating. In this approach, the gas expansion process is carried out in multiple stages with reheating in between each stage. Consider the two-stage turbine expansion with reheating shown in Fig. b. The gas enters the first stage of the turbine at state A1, is expanded isentropically to an intermediate pressure Pₐ₂, is reheated at constant pressure to state B1, and is expanded in the second stage isentropically to the…

What are the practical limitations to maximum work being able to be done from an engine when all the processes ard reversible.

19

If the turbine in a Rankine cycle operated with a second law efficiency less than 100%, how would the actual exiting quality compare to the ideal exiting quality?

an ideal Rankine cycle (fluid flow rate is 8 kg/s) operating between upper and lower pressures of 5 and 10,000 kPa. Draw a schematic of the components of this cycle. Draw the cycle on a P-v phase diagram and a T-s diagram. Find the power output of the turbine, the power input needed for the pump, and the overall cycle thermal efficiency.