What is the effect on cycle efficiency of condenser pressure decreases?

The overall effect of lowering the condenser pressure is an increase in the thermal efficiency of the cycle. The average temperature at which heat is added to the steam can be increased without increasing the boiler pressure by superheating the steam to high temperatures.

What are the factors affecting the efficiency of Rankine Cycle?

There are many factors affecting the Organic Rankine Cycle’s (ORC) performance, such as working fluid selection, evaporator and condenser temperatures, pinch point temperature differences (the minimum temperature difference between refrigerant and the waste heat source (PPTDevap) or cooling water (PPTDcon)).

How can increase the efficiency of the Rankine Cycle?

There are three ways to increase the efficiency of the simple ideal Rankine cycle.

1. Decreasing the condenser pressure. The effect of lowering the condenser pressure on the Rankine cycle efficiency is illustrated on a T-s diagram on the left.
2. Superheating the steam to a high temperature.
3. Increasing the boiler pressure.

What is the purpose of condenser in Rankine Cycle?

Originally Answered: Why is a condenser used in a Rankin cycle? A condenser is used to convert the steam from the exit of the turbine to saturated liquid. This is done so that we can use a pump to pressurize the liquid. There is no mechanical device till date which can work on steam+liquid mixture.

What is Rankine cycle efficiency?

The efficiency of the Rankine cycle is limited by the high heat of vaporization of the working fluid. This gives a theoretical maximum Carnot efficiency for the turbine alone of about 63.8\% compared with an actual overall thermal efficiency of less than 50\% for typical power stations.

Does a condenser increase or decrease pressure?

Temperature profile inside the condenser In a similar way to evaporation, the only pressure difference between the entrance and the exit of the heat exchanger is the pressure drop. Because the flow velocity in a condenser decreases, the induced pressure drop is much lower than in an evaporator.

What is the efficiency of Rankine cycle?

In modern nuclear power plants, which operate the Rankine cycle, the overall thermal efficiency is about one-third (33\%), so 3000 MWth of thermal power from the fission reaction is needed to generate 1000 MWe of electrical power.

Why efficiency of Rankine cycle is less than Carnot cycle?

The thermal efficiency of a Rankine cycle is lower then that of a Carnot cycle operating between the same temperature levels. This is primarily because of the fact that the energy transfer as heat in the boiler does not take place at constant temperature in the Rankine cycle.

When the condenser pressure of an ideal Rankine cycle is reduced below atmospheric pressure the thermal efficiency tends to?

Introducing Vapor Power Plants ►The fossil-fueled vapor power plant of Fig. 8.1(a) will be considered as representative. The overall plant is broken into four major subsystems identified by A, B, C, and D. Water is the working fluid.

Which condition of Rankine cycle has highest efficiency?

According to the Carnot process, the highest efficiency is reached if heat transfer occurs isothermally. To preheat the feed liquid to its saturation temperature, bleed vapor from various positions of the turbine is passed through external heat exchangers (regenerators), as shown in Figure 5.

What happens when condenser pressure increases?

Figure 3.15 shows the effect of increasing condenser inlet pressure on the exergy efficiency and energetic COP of the heat pump cycle. Increasing the outlet temperature from 77 °C to 97 °C causes both the exergy efficiency and the energetic COP of the system to decrease. Figure 3.15.

When condenser pressure is increased performance is?

As indicated in Figure 5 as the condenser pressure increases the steam entering to the condenser increases. The main reason is when the condenser pressure is high, the turbine is exit enthalpy is high and the specific turbine power output is low.

How can I increase the efficiency of the Rankine cycle?

There are three ways to increase the efficiency of the simple ideal Rankine cycle. 1. Decreasing the condenser pressure The effect of lowering the condenser pressure on the Rankine cycle efficiency is illustrated on a T-s diagram on the left.

How does steam temperature affect the thermal efficiency of Rankine cycle?

Thermal efficiency of the rankine cycle increases on account of increase in steam temperature. One desirable effect of increasing the increasing the steam temperature is that it doesn’t allow to the last stage mositure \% of steam to increase. This effect can be easily seen on the T-s diagram (Fig:2) above.

How does the condenser pressure affect the work done by the turbine?

By lowering the condenser pressure, the steam is condensed at a lower pressure thus resulting in more expansion through the Turbine which increases the net work done by the turbine. This can be visualised easily through the T-S diagram of Rankine Cycle. This is the simplest form of Rankine cycle on T-S plot.

What is the effect of lowering the operating pressure of condenser?

lowering the operating pressure of the condenser lowers the temperature at which heat is rejected. The overall effect of lowering the condenser pressure is an increase in the thermal efficiency of the cycle.