scholarly journals Methodology of Supervision by Analysis of Thermal Flux for Thermal Conduction of a Batch Chemical Reactor Equipped with a Monofluid Heating/Cooling System

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Ghania Henini ◽  
Fatiha Souahi ◽  
Ykhlef Laidani
Keyword(s):  
Thermal Conduction ◽  
Cooling System ◽  
Batch Reactor ◽  
Thermal Flux ◽  
Exothermic Reaction ◽  
Chemical Reactor ◽  
Thermal Control ◽  
Ride Quality ◽  
Heating And Cooling

We present the thermal behavior of a batch reactor to jacket equipped with a monofluid heating/cooling system. Heating and cooling are provided respectively by an electrical resistance and two plate heat exchangers. The control of the temperature of the reaction is based on the supervision system. This strategy of management of the thermal devices is based on the usage of the thermal flux as manipulated variable. The modulation of the monofluid temperature by acting on the heating power or on the opening degrees of an air-to-open valve that delivers the monofluid to heat exchanger. The study shows that the application of this method for the conduct of the pilot reactor gives good results in simulation and that taking into account the dynamics of the various apparatuses greatly improves ride quality of conduct. In addition thermal control of an exothermic reaction (mononitration) shows that the consideration of heat generated in the model representation improve the results by elimination any overshooting of the set-point temperature.

A feedback temperature control in a chemical reactor with high inertia of its cooling system

1984 ◽  
Vol 49 (7) ◽  
pp. 1642-1652 ◽  
Author(s):  
Josef Horák ◽  
František Jiráček ◽  
Libuše Ježová
Keyword(s):  
Mathematical Model ◽  
Temperature Control ◽  
Cooling System ◽  
Batch Reactor ◽  
Time Derivative ◽  
Exothermic Reaction ◽  
Chemical Reactor ◽  
The One ◽  
The Mathematical Model ◽  
The Given

In this work we compare simple algorithms for the one-off feedback temperature control of the reaction mixture in a batch reactor during an exothermic reaction. The aim of the control was to maintain the temperature of the mixture within the given range, and simultaneously, to minimize the number of the regulator switchings. The temperature control of the mixture was being performed at conditions when working states of the reactor in an open regulation loop are unstable and when the response of the cooler to regulation is slow. The following control algorithms were compared: P - regulator, PD - regulator and algorithms based on a prediction mathematical model including its adaptive variant. The results indicate that the algorithms based on the mathematical model are more efficient. However, the precision of the control can be diminished due to error in the time derivative of the temperature of the reaction mixture which forms the input to the prediction model. The adaptive variant of the algorithms was advantageous in cases when it was necessary to make up for significant errors in initial estimates of parameters of the prediction mathematical model.

Temperature control in chemical reactors with slow response of the cooling system; Definition of coefficients of control safety

1983 ◽  
Vol 48 (3) ◽  
pp. 711-721 ◽  
Author(s):  
Josef Horák ◽  
František Jiráček
Keyword(s):  
Temperature Control ◽  
Cooling System ◽  
Operating Temperature ◽  
Batch Reactor ◽  
Exothermic Reaction ◽  
Chemical Reactor ◽  
Loop Control ◽  
Information Safety ◽  
Definition Of ◽  
Reactor Operating

Coefficients of static, dynamic and information safety are defined. They cold be used for consideration of how difficult is the feedback of temperature control in a chemical reactor with exothermic reaction. An analysis is made for a batch reactor which should be kept in a pseudostationary state which is unstable at the open control loop. Control is based on measurement of the reaction mixture temperature and on evaluation of temperature derivative with time. The action quantity is flow rate of the carrier in the cooling system. The result of an analysis is the highest operating temperature of the mixture at which the safety of the reactor operation is still secured and further the trajectory on which it is possible to reach in the shortest time the given operating temperature at preserving safety of the reactor operating.

A two-point regulator control of a chemical reactor; Cooling system with a large inertia - PD algorithm

1983 ◽  
Vol 48 (9) ◽  
pp. 2627-2635 ◽  
Author(s):  
Josef Horák ◽  
František Jiráček ◽  
Libuše Ježová
Keyword(s):  
Temperature Control ◽  
Cooling System ◽  
Batch Reactor ◽  
Chemical Reactor ◽  
Slow Response ◽  
Practical Utilization ◽  
Laboratory Scale Reactor ◽  
Combined Simulation ◽  
Rate Of Response

The effect has been investigated of the gain of the derivative element of a PD controller on the quality of the temperature control of an exothermal reaction mixture in a batch reactor. The investigation concerned a reactor equipped with a cooling system whose rate of response could be varied in the range of several orders of magnitude. The results have lead to the conclusion that a slow response of the coolong system is difficult to make up for by using more sophisticated control algorithms. For the slow response of the cooling system the range of gain of the controller providing for a safe temperature control is narrow leaving essentially no margin for its practical utilization. The study combined simulation on a mathematical model with experimental verification of a laboratory scale reactor cooled by a submersible retractable cooler.

A simplified method of temperature control maximizing productivity of the batch reactor; The effect of inertia of the cooling system

1982 ◽  
Vol 47 (2) ◽  
pp. 454-464 ◽  
Author(s):  
František Jiráček ◽  
Josef Horák
Keyword(s):  
Mathematical Model ◽  
Temperature Control ◽  
Cooling System ◽  
Batch Reactor ◽  
Exothermic Reaction ◽  
Cooling Capacity ◽  
Variable Activity ◽  
Simplified Method ◽  
Opening And Closing ◽  
Time Of Operation

The effect has been studied of the inertia of the cooling system on the reliability of control of the temperature of the reaction mixture. The study has been made using a mathematical model of the batch reactor with an exothermic reaction. The temperature has been controlled by a two-level controller opening and closing the flow of the coolant. The aim of the control has been to maintain a constant value of the degree of utilization of the cooling capacity of the reactor. The instantaneous value of the degree of utilization has been assessed from the ratio of times for which the cooling system is idle to the time of operation. The reliability of control has been studied for variable activity of the catalyst.

Temperature control in a chemical reactor through variable area of the heat transfer surface. Experimental verification

1982 ◽  
Vol 47 (2) ◽  
pp. 446-453
Author(s):  
Josef Horák ◽  
František Jiráček ◽  
Libuše Ježová
Keyword(s):  
Batch Reactor ◽  
Exothermic Reaction ◽  
Chemical Reactor ◽  
Open Loop ◽  
Heat Transfer Surface ◽  
Laboratory Reactor ◽  
Hysteresis Control ◽  
Relay With Hysteresis ◽  
Rate Of Response ◽  
The Ideal

A possibility has been tested in the paper of the feed back control of temperature of the reaction mixture in a batch reactor with an exothermic reaction through the variable area of the cooling surface. The measurement were carried out in a laboratory reactor with a retractable cooler which was being immersed into the reaction mixture. The speed of motion of the cooler was sufficiently high permitting the process of immersion to be regarded as practically instantaneous. The aim of the control was to stabilize the set point temperature of the reaction mixture by a two-point controler. In dependence on the rate of response of the system to a change of the section variable either the ideal relay or the relay with hysteresis control algorithmus were used. The results of measurements showed that with the aid of a retractable cooler the temperature could be controlled safely even in those cases, in which the control by the variable flow rate of the coolant was unfeasible. The verification was carried out in the open-loop instable operating point of the reactor.

Temperature control in a chemical reactor through variable area of the heat transfer surface. Simulation analysis

1982 ◽  
Vol 47 (2) ◽  
pp. 430-445
Author(s):  
Josef Horák ◽  
Zina Valášková
Keyword(s):  
Heat Exchange ◽  
Simulation Analysis ◽  
Batch Reactor ◽  
Chemical Reactor ◽  
Rate Of Change ◽  
Action Variable ◽  
Heat Exchange Surface ◽  
Relay With Hysteresis ◽  
Exchange Surface

An algorithm has been developed and on a mathematical model analyzed to stabilize the reaction temperature of a batch reactor. The reaction has been a zero-order one and the reactor has been operated in a instable operating point. The action variable is the heat exchange surface whose area is increased if the temperature is above, or decreased if the temperature is below the set point. The following two-point regulators have been studied: An ideal relay, a relay with hysteresis and an asymmetric PD relay. The effect has been discussed of the parameters of the regulators on the quality of regulation. Stability analysis has been made of the stationary switching cycles and the domains of applicability have been determined for individual regulators with respect to the rate of change of the area of heat exchange surface.

scholarly journals Predictive functional control of temperature in a pharmaceutical hybrid nonlinear batch reactor

2013 ◽  
Vol 19 (4) ◽  
pp. 573-582 ◽  
Author(s):  
Simon Stampar ◽  
Sasa Sokolic ◽  
Gorazd Karer
Keyword(s):  
Temperature Control ◽  
Control Algorithm ◽  
Batch Reactor ◽  
Pharmaceutical Product ◽  
Control Law ◽  
Batch Reactors ◽  
Heating And Cooling ◽  
Pharmaceutical Substances ◽  
Functional Control

These days, in times of recession, we are forced by competitiveness and the optimization of production to lower the costs of the temperature control in pharmaceutical batch reactors and increase the quantity and quality of the produced pharmaceutical product (active pharmaceutical substances). Therefore, a control algorithm is needed which provides us rapid and precise temperature control. This paper deals with the development of a control algorithm, where two predictive functional controllers are connected in a cascade for heating and cooling the content of the hybrid batch reactor. The algorithm has to be designed to cope with the constraints and the mixed discrete and continuous nature of the process of heating and cooling. The main goal of the control law is to achieve rapid and exact tracking of the reference temperature, good disturbance rejection and, in particular, a small number of heating and cooling medium switchings. The simulation results of the proposed algorithm give us much better performance compared to a conventional cascade PI algorithm.

scholarly journals The use of mathematical modeling for the construction of a control system for a climate chamber

2019 ◽  
Vol 2 (1) ◽  
pp. 562-569
Author(s):  
Marian Banaś ◽  
Mariusz Filipowicz ◽  
Krzysztof Lalik ◽  
Sławosz Kleszcz ◽  
Szymon Podlasek ◽  
...  
Keyword(s):  
Cooling System ◽  
Climate Chamber ◽  
Precise Control ◽  
Heating And Cooling ◽  
Advanced Control ◽  
Air Handling Units ◽  
Temperature Parameter ◽  
Executive Elements ◽  
Proper Operation

Abstract Due to the introduced political instruments, as well as the increase in awareness and standard of living, mechanical ventilation is becoming more and more popular in Poland. The growing market and standards force the manufacturers of air handling units to constantly improve the quality of their products. In order to verify the operation of these devices, it is necessary in a specially adapted for this object called the climate chamber. Due to the strict regulations regarding the working conditions of the said facilities, it is necessary to apply the processes of advanced control systems in the process of regulation. These processes are aimed at establishing stable parameters of air supplied to the tested objects, ventilation and air-conditioning units such as: temperature, humidity, flux. Due to the need for precise control and operation of the installation in industrial conditions, it was decided to use the PID controller. The article deals with the optimization of the heating and cooling system, because the temperature parameter was a problematic element in the proper operation of the climate chamber. Both the heating and cooling systems have been described and executive elements have been emphasized, thanks to which it was possible to control the flow of circulating factors. The procedure of selection and implementation of the regulator's settings and its influence on the operation of the climate chamber was also analyzed.

scholarly journals Development of a Simulation Model for Controlling and Improving the Productivity of Batch Reactors

2013 ◽  
Vol 15 (1) ◽  
pp. 78-87 ◽  
Author(s):  
Ghania Henini ◽  
Fatiha Souahi ◽  
Ykhlef Laidani
Keyword(s):  
Simulation Model ◽  
Cooling System ◽  
Batch Reactor ◽  
Fluid Flows ◽  
Batch Reactors ◽  
Unsteady State ◽  
Constant Flow Rate ◽  
Heating And Cooling ◽  
Dynamic Simulator ◽  
The Heat Balance

This paper describes the development of a dynamic simulator model for a jacketed batch reactor equipped with a mono-fluid heating/cooling system. The Mono-fluid flows at constant flow-rate through the jacketed reactor. The heating and cooling are assured respectively by electrical resistance and two plate heat exchangers. A detailed description of the equations leading to the development of simulation model is presented. The model is based on writing the equations of the mass balance and the heat balance for the reactor and the thermal loop in unsteady state. To validate the simulation model, we first studied the thermal behavior of the reaction mixture during heating and cooling, using water as the reaction mixture. We then considered the consecutive chemical reaction of the synthesis of cyclopentanediol from cyclopentadiene by studying the yield of this reaction. The results show that heating the reaction mixture increases significantly the yield of this synthesis reaction.

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