Last time we ran our basic power plant steam turbine without a condenser. In that configuration the steam from the turbine exhaust was simply discharged to the surrounding atmosphere. Today we’ll connect it to a condenser to see how it improves the turbine’s efficiency. As discussed in a previous blog, enthalpy his,_{1 }
If the condenser vacuum exists at a pressure of 0.6 PSI, a realistic value for a power plant condenser, then referring to the steam tables in the Van Wylen and Sonntag thermodynamics book, we find that the enthalpy
and the amount of useful work that the turbine can perform with the condenser in place would therefore be,
h1474 BTU/lb – 847 BTU/lb = 627 BTU/lb_{2} = So essentially with the condenser present, the work of the turbine is increased by 168 BTU/lb (627 BTU/lb – 459 BTU/lb). To put this increase into terms we can relate to, consider this. Suppose there’s one million pounds of steam flowing through the turbine each hour. Knowing this, the turbine power increase,
Now according to
A typical automobile has a 120 HP engine, so this equation tells us that the turbine horsepower output was increased a great deal simply by adding a condenser to the turbine exhaust. In fact, it was increased to the tune of the power behind approximately 550 cars! What all this means is that the stronger the vacuum within the condenser, the greater the difference between h will be. This results in increased turbine efficiency and work output, as evidenced by the greater numeric value for _{2}W. Put another way, the turbine’s increased efficiency is a direct result of the condenser’s vacuum forming action and its recapturing of the steam that would otherwise escape from the turbine’s exhaust into the atmosphere.This wraps up our series on the power plant water-to-steam cycle. Next time we’ll use the power of 3D animation to turn a static 2D image of a centrifugal clutch into a moving portrayal to see how it works. ________________________________________ |

## Posts Tagged ‘steam pressure’

### How Condensers Increase Efficiency Inside Power Plants

Wednesday, December 4th, 2013### Enthalpy and the Potential for More Work

Monday, November 18th, 2013
Last time we learned how enthalpy is used to measure heat energy contained in the steam inside a power plant. The higher the steam pressure, the higher the enthalpy, and vice versa, and we touched upon the concept of Let’s revisit the equation introduced last time, which allows us to determine the amount of useful work output:
h_{2} Applied to a power plant’s water-to-steam cycle, enthalpy As for enthalpy Next week we’ll see how the condenser, and more specifically the vacuum inside of it, sets the platform for increased energy production, a/k/a
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### Enthalpy and Steam Turbines

Thursday, November 14th, 2013
Last time we learned how the formation of condensate within a power plant’s turbine results in a vacuum being created. This vacuum plays a key role in increasing steam turbine efficiency because it affects a property known as The term ^{th} Century. As discussed in a previous blog article, thermodynamics is the science that deals with heat and work present within processes. Enthalpy is a key factor in thermodynamics, and is commonly represented in engineering calculations by the letter h and denoted as, where u is the internal energy of a substance, let’s say steam; P is the pressure acting upon a specific volume, v, of the steam; and P and v are multiplied together. Pressure is force per unit area and is measured in psi, pounds per square inch. For the purposes of our discussion, it’s the amount of pressure that steam places on pipes containing it. Looking at the equation above, simple math tells us that if we increase the pressure, When it comes to steam turbines, thermodynamics tells us that the amount of h_{2} In terms of the illustration below, W stands for work, or potential for useful outcome of the turbine/generator process in the form of electricity, h We’ll discuss the importance of enthalpy in more detail next week, when we’ll apply the concept to the work output of a steam turbine.
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