Do we have the expertise to optimize operation of our refrigeration plant? (1)

Typically, there are two ways to improve the energy efficiency of existing refrigeration plants:

-  Using energy saving equipment (PLCs, VFDs)

-   Optimizing operation of the refrigeration plant

Usually, energy saving equipment is expensive and investments in this equipment have several years payback.

Right now, many companies are focused on optimizing operation of their refrigeration plants. This is the best way to save energy in industrial refrigeration. However, this approach requires specific knowledge and experience of the optimization process. I think that many companies have improved the operation of their refrigeration plants, but usually, it is just partial optimization. We will have a look at the optimization of the condensing pressure.

Optimum condensing pressure.

During summer operation, condensing pressure should float up and down based on the wet bulb temperature. Typically, the wet bulb approach is a variable that should be controlled. To optimize condensing pressure, an operator should answer the following questions:

-   What is the optimum condenser (pumps, fans) sequence?

-    What is the optimum wet bulb approach?

-    How does the optimum wet bulb approach change with variation of the wet bulb temperature?

Optimum wet bulb approach will be different for different wet bulb temperatures. Some refrigeration plant control system does not have the wet bulb approach feature. How condensing pressure should be controlled for these refrigeration plants?

The idea of the wet bulb approach feature is to minimize total (compressors + condensers) energy use by balancing capacities of the compressors and of the condensers. I found two other ways to balance capacities of the compressors and of the condensers which do not require sophisticated PLC and the wet bulb approach feature. To maximize efficiency of their refrigeration plants, every company should ask themselves. Do we have expertise to fully optimize condensing pressure during summer operation?