Optimization of the Dehydration Process in the Manufacture of NT Series Compressors
Abstract
The article presents the results of optimizing the final production process (the time of required dehydration) of an industrially produced compressor. Optimization is based on simulations carried out that were conducted in ANSYS CFX. Several variants were tested in which the process parameters were varied (the inside diameter of the tube, the flow at the inlet and outlet temperature). The results of the simulations show which the parameters of the compressor speed up the dehydration process and what consequences shortening of process will have for of the whole production of the compressor. Optimization of the compressor manufacturing process was performed for the NT series compressor. The compressor is the largest industrial compressor manufactured in a specialized global company.
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Introduction
The study of the dehydration process was designed for a globally operating company, one of whose sites is based in Slovakia. This is a company that is a leader in its field. It specializes in the manufacture of hermetic compressors. In its plants worldwide, the company produces more than 35 million compressors. It also produces devices that function as part of the condensing units of electrical systems to make smart appliances. The company in Slovakia specializes in the production of compressors for commercial refrigeration and production of condensing units. In 2011 it also began to produce the global Mini platform for home cooling.
One of the compressor series includes compressors for commercial refrigeration. This includes compressors from the series NE/NEK, NT, NTU and NJ. These compressors are different from compressors for household refrigeration in terms of design and construction. Compressors for commercial refrigeration have higher cooling capacity and higher resistance to extreme conditions in which operation takes place.
Manufacture of compressors on the production line consists of a number of interlinked processes. Individual processes run with various time-intensities, hence the need for optimization in order to shorten the production time of a compressor unit. One of the longest processes in the manufacture of compressors is dehydration. Since the process currently takes up to 5 hours it needs to be optimized to shorten the overall production time of the compressor and to reduce production costs in manufacturing the compressor.
The process of dehydration can be simulated in ANSYS CFX. The simulation shows how the process runs, either under the current state or under changed conditions. The results of the simulations also show under what conditions the process would accelerate, thus reducing the consumption of electricity necessary to observe the process.
Conclusion
By evaluating all the variants of simulations it was found that the dehydration process can be accelerated by up to 100 minutes. This shortening of the dehydration process can have an impact on the overall production of the compressor. It can be stated that in the process of dehydration more compressors can be heated per day. It has also been shown that the same number of compressors can be produced as today with lower operating costs for the electric oven. It is therefore a matter for the company to decide whether to produce more compressors per day or to produce the current number of compressors with lower production costs. In production with the current number of compressors the company can save more than 27% of the cost of operating the electric ovens used in the dehydration process.