CN213634131U - Cascade PID (proportion integration differentiation) -based intelligent particle moisture control system - Google Patents

Abstract

The utility model discloses a particle moisture intelligent control system based on cascade PID, which is characterized in that a PID main controller, a compensator, a microwave heating time regulator, a temperature cascade PID controller, a microwave heating power regulator, a paving thickness cascade PID controller, a paving thickness adjusting baffle and an outlet moisture meter are sequentially connected in series behind an inlet moisture meter and then connected in parallel with a moisture content transmitter to form a moisture content feedback loop; a temperature transmitter is connected in parallel between the temperature cascade PID controller and the spreading thickness cascade PID controller to form a temperature feedback loop; and a paving thickness transmitter is connected in parallel between the paving thickness cascade PID controller and the paving thickness adjusting baffle plate to form a temperature feedback loop. The utility model discloses can improve the granule moisture content controllability of microwave drying technology, reduce granule moisture content numerical error fast, stabilize moisture content fluctuation range, eliminate moisture content control hysteresis quality.

Description

Cascade PID (proportion integration differentiation) -based intelligent particle moisture control system

Technical Field

The utility model relates to a be applied to novel tobacco products heating for cigarette moisture intelligence control system of granule microwave drying technology, especially a moisture intelligence control system based on cascade PID.

Background

The granular heating cigarette is an original product of Chinese tobacco in the field of novel tobacco products. After the granulation process is finished, the tobacco releasing particles (including tobacco particles and non-tobacco particles) of the granular type heating cigarette need to be treated by a drying process, and then the subsequent cigarette filling forming and finished product packaging links can be carried out.

The microwave drying has the advantages of batch and continuous production and furthest reservation of the original fragrant substances of the particles, and is a better drying process of the particles for the particle-type heated cigarettes. In the particle microwave drying process, the quality of particle type heating cigarette products is seriously influenced by the control level of the water content. Most of the existing particle microwave dryers adopt an open-loop control system, manual control is performed by depending on production actual experience of operators more, and meanwhile, the problems of poor moisture control capability, large fluctuation of water content of products, artificial control lag, low control precision, power supply voltage change inhibition, poor load disturbance capability and the like exist. The influence on the control of the water content of the particles is mainly caused by factors such as the fluctuation of the surface temperature of the particles, the change of the paving thickness, manual operation errors and the like.

Disclosure of Invention

In order to solve the problems of the existing control system of the microwave dryer, the utility model provides a particle moisture intelligent control system based on cascade PID, so as to improve the particle moisture content control capability of the microwave drying process, rapidly reduce the numerical error of the particle moisture content, stabilize the fluctuation range of the moisture content and eliminate the hysteresis of the moisture content control; and the influence of factors such as untimely and inaccurate manual operation is reduced.

The utility model discloses a reach above-mentioned utility model purpose, adopt following technical scheme:

the utility model relates to a particle moisture intelligent control system based on cascade PID, which is characterized in that the system is applied to a particle microwave drying process for heating cigarettes and is connected with a first-stage closed-loop negative feedback loop in series after a moisture meter is arranged at an inlet;

the first-stage closed loop negative feedback loop is formed by sequentially connecting a PID main controller, a compensator, a microwave heating time regulator, a temperature cascade PID controller, a microwave heating power regulator, a paving thickness cascade PID controller, a paving thickness adjusting baffle and an outlet moisture meter in series to form a moisture content main control loop, and then connecting the moisture content main control loop and a moisture content transmitter in parallel to form a moisture content feedback loop;

a temperature transmitter is connected in parallel between the temperature cascade PID controller and the spreading thickness cascade PID controller to form a second-stage closed-loop negative feedback loop as a temperature feedback loop;

and a paving thickness transmitter is connected in parallel between the paving thickness cascade PID controller and the paving thickness adjusting baffle plate to form a third-stage closed-loop negative feedback loop and serve as a paving thickness feedback loop.

Compared with the prior art, the beneficial effects of the utility model reside in that:

1. the utility model discloses with stone material thickness PID controller, granule surface temperature PID controller establishes ties to moisture content main control circuit in, stone material thickness has been found, granule surface temperature, the three closed loop negative feedback control circuit of granule moisture, the high efficiency has reduced granule surface temperature, the lag to moisture control such as stone material thickness, undulant influence, simultaneously with load disturbance introduce the interior return circuit of stone material thickness control, supply voltage changes and introduces the interior return circuit of granule surface temperature control, moisture control has greatly improved the restraining capacity to the interference.

2. The utility model applies three closed-loop negative feedback control loops to form three closed-loop negative feedback; the intelligent control of stable, accurate, delay-free and self-adaptive adjustment of the water content of the particles is realized; the control capability of the water content of the granules is greatly improved, the water fluctuation of the dried granules is stabilized, the hysteresis of water control is eliminated, and the influence of factors such as untimely manual control and poor precision is reduced to a great extent.

Drawings

Fig. 1 is a schematic structural diagram of the intelligent control system of the present invention;

fig. 2 is the intelligent control mode diagram of the microwave drying process for heating the particles for cigarettes.

Detailed Description

In this embodiment, as shown in fig. 1 and 2, a cascade PID-based intelligent particle moisture control system is applied to a microwave drying process of particles for heating cigarettes, and is connected in series with a first-stage closed-loop negative feedback loop after entering a moisture meter; an inlet moisture meter collects actual value PV of moisture content of wet particles at a feeding end₀；

The first-stage closed loop negative feedback loop is formed by sequentially connecting a PID main controller, a compensator, a microwave heating time regulator, a temperature cascade PID controller, a microwave heating power regulator, a paving thickness cascade PID controller, a paving thickness adjusting baffle and an outlet moisture meter in series to form a moisture content main control loop, and then connecting the moisture content main control loop and a moisture content transmitter in parallel to form a moisture content feedback loop; wherein, the outlet moisture meter collects the actual value PV of the water content of the dry particles at the outlet end₁The spreading thickness adjusting baffle plate collects the height of the baffle plate, namely the actual spreading thickness PV₃(ii) a The compensator being microwave-driedThe independent variable of the ternary complex function determined by the equipment process parameters can be obtained according to the equipment process control data and the operation experience, and is correspondingly corrected according to the test structure. The temperature cascade PID controller is a device for PID control of temperature. The paving thickness cascade PID controller is a device for PID control of the paving thickness of the particles.

Taking the water content feedback as the feedback of a main control loop; the actual value PV of the outlet moisture is measured₁Feeding back to the input end of the PID main controller; the output value of the PID main controller determines the set value of the temperature cascade PID controller, and the PID main controller determines the actual value PV of the inlet moisture according to the actual value PV of the inlet moisture₀With the outlet moisture setpoint SP₁The deviation of the first-time microwave drying equipment is used as the initial condition of the cascade control system, and the initial process function f of the first-time microwave drying equipment is calculated through a compensator₀(T, T, δ); wherein f is₀(T, T, delta) is a ternary complex function of microwave process parameters of heating time T, heating temperature T and paving thickness delta, and the microwave process parameters under the initial condition are determined by the initial process function f (T, T, delta) to execute microwave drying operation; after the particles are dried, the PID main controller is used for controlling the outlet water content PV₁With the outlet moisture setpoint SP₁The deviation is corrected by a compensator to calculate a process function f (T, T, delta), and the corrected process function determines microwave process parameters to execute microwave drying operation;

a temperature transmitter is connected in parallel between the temperature cascade PID controller and the spreading thickness cascade PID controller to form a second-stage closed-loop negative feedback loop as a temperature feedback loop; the temperature feedback loop converts the actual value PV of the particle surface temperature₂Feeding back to the input end of the temperature cascade PID controller; and introducing power supply voltage change disturbance into a temperature feedback control loop; the temperature sensor collects the particle surface temperature PV under the condition of power supply voltage variation and other interference factors₂. Taking the heating time t determined by the process function corrected by the compensator as an input value for adjusting the microwave heating time; the temperature cascade PID controller converts the actual value PV of the particle surface temperature₂With a particle surface temperature setpoint SP₂Calculating the microwave heating power value according to the deviation;

in spreading thickness cascade PID controllerA paving thickness transmitter is connected in parallel between the paving thickness adjusting baffle and the paving thickness adjusting baffle to form a third-stage closed-loop negative feedback loop which is used as a paving thickness feedback loop; the paving thickness feedback loop feeds the actual value PV of the paving thickness of the particles₃Feeding back to the input end of the spreading thickness cascade PID controller; introducing load disturbance into a paving thickness feedback control loop; the paving thickness cascade PID controller enables the paving thickness actual value PV₃Calculating the adjusting parameter of the paving thickness baffle plate by the deviation of the paving function set value SP3 determined by the process function; to sum up, the process stabilizes the particle outlet moisture value PV₁。

Use the utility model discloses an intelligent control system and traditional manual control system moisture control effect contrast as follows:

TABLE 1 the utility model discloses an intelligent control system and traditional manual control system moisture control effect

Can know by table 1, adopt the utility model discloses an intelligent control system has very big improvement than traditional manual control system's moisture control effect, and granule moisture content, temperature control precision all have better promotion.

Claims (1)

1. A granule moisture intelligent control system based on cascade PID is characterized in that the system is applied to a granule microwave drying process for heating cigarettes, and is connected with a first-stage closed loop negative feedback loop in series after a moisture meter is arranged at an inlet;

the first-stage closed loop negative feedback loop is formed by sequentially connecting a PID main controller, a compensator, a microwave heating time regulator, a temperature cascade PID controller, a microwave heating power regulator, a paving thickness cascade PID controller, a paving thickness adjusting baffle and an outlet moisture meter in series to form a moisture content main control loop, and then connecting the moisture content main control loop and a moisture content transmitter in parallel to form a moisture content feedback loop;

a temperature transmitter is connected in parallel between the temperature cascade PID controller and the spreading thickness cascade PID controller to form a second-stage closed-loop negative feedback loop as a temperature feedback loop;

and a paving thickness transmitter is connected in parallel between the paving thickness cascade PID controller and the paving thickness adjusting baffle plate to form a third-stage closed-loop negative feedback loop and serve as a paving thickness feedback loop.

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