Valve Failure Positions; Controlling Global Processes

Readers Ask About PID Controller Action, Valve Failure Positions and Global Process Trends for Industrial Applications

By Bela Liptak

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We can also measure the oceans' salt content at locations both near the Equator, where increased heat input increases evaporation and, therefore, the ocean surface becomes saltier, and to the north, where increased precipitation causes it to drop (Figure 2). The dynamics of this "water circulation loop" and the rate at which the salt concentration difference is rising is another undeniable indicator of the rising heat input of the planet.

Naturally, in addition to the increased rate of water circulation, the same cycle is taking place below the oceans' surface, because the melting ice near the poles further reduces the salt content of the ocean, which slows the ocean currents and increases the formation of tornados and hurricanes, as I explained in detail in my articles in the March and May issues of Control in 2006 (March, Can Process Control Help Stabilize Global Warming?; May, Why Do We Have Global Warming?).

This increased circulation results in desertification (destruction of agriculture) at the evaporation end of the cycle and flooding at the other. The science of process control is important because by measuring the dynamics of this "open loop," we can tell where it will take the planet and when.

Now, as far as "closing the loop," we have to "throttle" its manipulated variable, which is human behavior! How do we do that? By education, explaining that there is a profession (process control) that can guide the smooth conversion of our lifestyle to be fueled by an inexhaustible, clean and free energy source, the Sun.

I could make the same argument for closing the loop on the relationship between the emission of radioactive substances and cancer, natural gas emission and allergy, the accumulation of endocrine disruptors from herbicides and obesity or the global destruction of the male hormones, etc., but I think the above example is enough to show that the science of process control is also applicable to non-industrial processes. 

Bela Liptak

A: Why did we stop talking about the old term "degree days," which we used in ASHRAE to size heat pumps.  The public gets only the record highs and lows, which are not related to energy. There is also no data on the global solar insolation. The reason why we have constant arguing over global warming is because we can't complete a simple energy balance on the earth or any other planet like Mars.

Reed Morton

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