Operating Engineers and Optimization

Recently I have found that many people believe that operating engineers should optimize the operation of the refrigeration plants. I personally disagree with this approach. Optimization of refrigeration plant operation is a very complicated issue. The operating engineers can not do it alone. They require help from experts to optimize the operation of the refrigeration plants.

Ideally, a refrigeration plant control should have:

1.     A software to determine optimum set points and optimum operating strategies.

2.     A PLC to implement these set points and operating strategies.

Currently, we have many PLCs on the market. Several of them can do a good job by implementing certain set points and operating strategies. However, we do not have software to determine optimum set points and optimum operating strategies. It is very complicated to create this type of software. Who should determine these set points and operating strategies?

Recently, several researches have been done to optimize operation of refrigeration plants. However, these were the master’s degree and PhD researches. Probably, nobody think that an operating engineer can do PhD research on his refrigeration plant. In reality, the initial steps of the optimization can be done by an operating engineer. However, he will likely require help from an expert for the final tuning up of the refrigeration plant.

Example.

A refrigeration plant was operated at minimum head pressure of 120psig.

An operating engineer determined that minimum allowable head pressure for his refrigeration plant can be 110psig. He found that at head pressure lower than 110psig, the evaporator coils at the far end of the plant will not defrost properly.

An expert reviewed the operation of this plant and determined that the winter average optimum head pressure for this plant is 60psig. The efficiency of the plant will improve when plant operating head pressure will be closer to 60psig. The expert suggested operation of this plant at 90psig of head pressure during periods of cool weather. However, defrosting at such low head pressure requires precise adjustment of hot gas supply, back pressure regulator and defrosting time. These adjustments were done and $40,000 of energy costs has been saved because all winter this plant was operating at 90psig of head pressure.

I believe that operating engineers are the major players in energy savings in industrial refrigeration but they do require help from experts to maximize efficiency of the refrigeration plants.

Recently, I have found that some people disagree with the statements in my newsletters. I’m open to discussions, as only through opposing opinions will we will be able to find the truth. If you have a different opinion or questions, please feel free to send it to me.