Identification of heat exchange process in the evaporators of absorption refrigerating units under conditions of uncertainty

Kravchenko

et al. 2018

Self Cite

Section: Materials and Methods To Study Influence Of The Consumption mentioning

confidence: 99%

Section: Literature Review and Problem Statementmentioning

confidence: 99%

Algorithmic tools for optimizing the temperature regime of evaporator at absorption-refrigeration units of ammonia production

Kravchenko

et al. 2018

Self Cite

“…There is also a change in the heat transfer coefficients in the system's devices. As shown in [10], this is caused by a change in the condensation thermal resistance and, mainly, by its dependence on the concentration of ammonia in CG at the input [6].…”

Section: Literature Review and Problem Statementmentioning

confidence: 97%

“…This is due to the influence of external heat load from CG. The uncertainty, as found in [6], relates to the impossibility of continuous automatic control over ammonia concentration in CG, both at the TSSC input and output. There is also a change in the heat transfer coefficients in the system's devices.…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

“…That leads to significant fluctuations in the TSSC temperature regime and deviations in the temperature of secondary condensation from the rated norm of −5 °C [5]. The increase in this temperature even by 1 °C in the synthesis units AM-1360 causes a decrease in the energy efficiency of production by increasing the annual consumption of natural gas by 307.3 thousand nm 3 [6]. Therefore, it is necessary to stabilize the temperature regime of TSSC at the regulatory level.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Design of an intelligent system to control the technological system of ammonia production secondary condensation

Kravchenko

et al. 2022

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This paper has analyzed the functioning conditions for the technological system of secondary condensation (TSSC) in a typical ammonia synthesis unit of the AM-1360 series with the use of a system-control approach. The coordinates of control vectors and external disturbances have been determined. An algorithm has been developed for predicting the coordinates of the control vector for the subsystem of decision support under the conditions of external disturbances for such a complex inertial object with high metal consumption as TSSC. The method of mathematical modeling was used to determine, based on the developed algorithm, the patterns and quantitative dependences of the influence of external disturbances such as the temperature of primary condensation and the flow rate of circulation gas on the efficiency of TSSC heat exchange processes. The regularity of increase in the heat flows and coordinates of control vector with an increase in the temperature of primary condensation has been established. The parametric sensitivity of the coordinates of the control vector under the conditions of change in the temperature of the primary condensation has been determined, which, compared with the circulation gas flow rate, exceeds it by more than six times. The executed software implementation of the algorithm employing the MATLAB programming environment makes it possible, owing to the embedded client part (ORC client), free software access to the current data on the technological process. The functional structure of computer-integrated TSSC technology with the proposed correction subsystem under a supervisory control mode has been designed. Correction solutions involving the additional hardware and software based on the programmable logic controller VIPA and SCADA-system Zenon have been practically implemented. The implementation of the developed system ensures the stabilization of the secondary condensation temperature at the regulatory level of −5 °C, which reduces the consumption of natural gas by almost 1 million nm3 per year.

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Designing energy-efficient hardware and technological structure of absorption refrigeration units for ammonia production

Babichenko,

Krasnikov,

Babichenko

et al. 2024