Now, let me explain why a condensing steam turbine needs to be evacuated before startup.

The exhaust pressure of a condensing steam turbine significantly affects operational economy. The primary factors influencing the vacuum level in the condenser are the inlet temperature of the cooling water and the cooling rate. The former is related to the region where the power plant is located, the season, and the method of water supply. Why is it necessary to remove dust before starting up? Our editor will explain it for you.

Get to know what a condensing steam turbine is in one minute.

A condensing steam turbine is a type of steam turbine in which, after the steam expands and does work within the turbine, virtually all of the steam—except for a small amount lost through shaft seals—is directed into the condenser, where it condenses into water. In practice, to enhance the thermal efficiency of a condensing steam turbine and reduce the diameter of the turbine’s exhaust cylinder, part of the steam that has already done work is extracted and sent to a regenerative heater to preheat the boiler feedwater.

Introduction to the Working Principle of Condensing Steam Turbines

The condenser commonly used in condensing steam turbines is of the surface type. The cooled water is circulated and reused in cooling towers. At power plants located near rivers and lakes, if water availability is sufficient, the discharged water can be directly released back into the rivers and lakes—this practice is known as runoff. However, this approach may cause thermal pollution to the rivers and lakes. In regions experiencing severe water shortages, power plants can employ air-cooled condensers. Yet due to their bulky structure and high consumption of metallic materials, they are rarely used in conventional power plants except for mobile power stations.

What’s going on with the condensing steam turbine’s cylinder being sealed?

A condensing steam turbine is one in which the steam expands and does work within the turbine, and except for a small amount of leakage from the shaft seals, all the steam is directed into the condenser, where it condenses into water. So, what exactly is "cylinder trapping" during the operation of a condensing steam turbine?

Some Key Points About Condensing Steam Turbines

Condensing steam turbines are widely used in thermal power plants for power generation. The condensing equipment mainly consists of a condenser, a circulating water pump, a condensate pump, and an air extraction device. The exhaust steam from the steam turbine enters the condenser, where it is completely cooled and condensed into water by the circulating water. The condensed water is then pumped out by the condensate pump, heated through various stages of heaters, and finally sent to the boiler as feedwater.

Next, let’s talk about the startup procedures for a condensing steam turbine.

With the widespread use of steam turbine equipment, manufacturers have made numerous design choices. Generally, the startup procedures for condensing steam turbines can be categorized into hot start, warm-state start, medium-temperature start, and cold-state start. Improper startup procedures can easily damage the equipment, disrupt its normal operation, reduce operational efficiency, and shorten its service life.