Automatic control system for the technological process of chlorella cultivation
Authors: Rakhmanov Sh , Azizova N , Abdullaeva D , Abduganiev A , Akbaraliev A , Kamolov E 
Published: July 2020

This article devoted to the implementation of mathematical models and algorithms in control problems of the chlorella cultivation process. The article gives us expanded concepts about the construction of the control functional – algorithmic structure, as well as the automation of various microbiological processes and productions, which based on modern computing devices, creation of a full-fledged complex for the task of chlorella mass cultivation process.

When building the control system, problems are solved: collection and primary processing of information, prediction of technological processes progress, optimization of mode parameters, process control.

Within the framework of these main tasks solutions have been found, which make it possible to facilitate the operator-technologist operational control or to implement reasonable management decisions depending on different production situations. For the considered class of objects, in particular the technological process of microalgae cultivation, the task of synthesis of control systems is to maintain the technological process at an optimal level that meets the technological and ecological standards of production.

One of the necessary conditions for the optimal conduct of the process of cultivation of microorganisms is automatic control of the content and composition of nutrients at the entrance, as well as control of the output indicators of the process.

The following technical tasks are also required to implement the management systems:

- Improvement of local control and control systems (pH, T, light.);

- Nutrient composition control, continuous medium circulation.

Periodicity of control tasks solution is established depending on process features, control object, process introduction mode, as well as the availability of a set of hardware.

As a result of the implementation of the proposed control system, the maximum ratio of chlorella concentration to its average value decreased by 23.8%.

Thus, the control system of the chlorella cultivation process provides a timely prediction of the technological process and the formation of control actions using a computing device, which contributes to an increase in the productivity of the cultivator by 8-12%.

Based on the theoretical and experimental studies performed as part of this work, the following main results were obtained:

1. Based on the developed models and algorithms, a functional-algorithmic structure of a control system for the chlorella cultivation process is proposed, oriented towards solving the following problems: collecting and primary processing of information, predicting the progress of the technological process, optimizing operating parameters and controlling the course of the technological process.

2. The implementation of the control system made it possible to increase the yield of chlorella from a unit of spent nutrients, to increase the productivity of the cultivator due to the strict maintenance of the optimal value of the residence time of the substrate particles in the apparatus.

3. The results obtained make it possible to draw a conclusion about the adequacy of the constructed models for the real process, the correctness of the selected control actions and optimality criteria, as well as the efficiency and effectiveness of the developed algorithms for optimizing and controlling the technological process of chlorella production cultivation.