The Rankine cycle is a way to turn heat into useful work. It's often used in power plants to generate electricity. Here are the four main parts of the cycle:

1. Boiler: This part heats water to turn it into steam. It does this by using a lot of heat and operates at high pressures, like 10-30 MPa, and very high temperatures, usually around 500-600°C.

2. Turbine: The steam produced in the boiler expands here. This expansion turns the steam's heat energy into mechanical energy, which can be used to do work. Steam turbines can be pretty efficient, working about 25% to 45% of the time.

3. Condenser: This part cools the steam and turns it back into water. When this happens, heat is released. The condenser works at lower pressures, typically around 0.1-0.6 MPa.

4. Pump: After the water has been turned back from steam, the pump increases the pressure of this water and sends it back to the boiler. This pump is quite efficient, usually working between 70% to 85%.

The efficiency of the Rankine cycle can be measured using a simple formula:

$$\eta = \frac{W_{net}}{Q_{in}} = \frac{Q_{in} - Q_{out}}{Q_{in}} = 1 - \frac{Q_{out}}{Q_{in}}$$

In this formula:

• $W_{net}$ is the amount of work done by the cycle,
• $Q_{in}$ is the heat added in the boiler,
• $Q_{out}$ is the heat released in the condenser.

Normally, the Rankine cycle is about 30% to 45% efficient. However, using special techniques like regenerative cycles and reheating can make it work even better.