CN110825055A - Hybrid production workshop energy-saving scheduling method considering continuous processing of heating furnace - Google Patents

Abstract

The invention discloses an energy-saving scheduling method for a mixed production workshop considering the continuous processing of a heating furnace, aiming at green manufacturing and energy-saving production, considering the continuous processing stage with heating furnace equipment and the intermittent processing stage of machining equipment, and analyzes different manufacturing processes. The various states of the processing equipment in the stage are established, and the optimization function of the machining equipment and the heating furnace equipment with the energy consumption as the goal in the production scheduling is established. The model goes through the following steps: establishing the energy consumption model of batch processing equipment in various time states; establishing the energy consumption model of continuous stage heating furnace equipment in various time states; The invention establishes an energy consumption optimization model for the mixed production workshop, and solves the energy saving scheduling problem of the mixed production workshop considering the continuous processing of the heating furnace by using the model.

Description

Energy-saving scheduling method of mixed production workshop considering continuous processing of heating furnace

technical field

The invention relates to a scheduling technology of a mixed production workshop, in particular to a modeling method for an energy-saving scheduling model of a mixed production workshop considering continuous processing and intermittent processing of a heating furnace, and belongs to the technical field of advanced manufacturing control and scheduling.

Background technique

With the rapid development of modern manufacturing technology, the research focus in the field of production scheduling is gradually focusing on intelligent manufacturing and green manufacturing. Especially driven by sustainable development planning, energy has become one of the most important resources for manufacturing enterprises. How to reduce manufacturing The energy loss in the process is a manufacturing problem that needs to be solved urgently.

The problem of energy-saving scheduling in processing workshops widely exists in actual production workshops. In the processing stage of mixed processing workshops, the energy consumption of thermal processing equipment such as heat treatment (such as heating furnaces) is significantly higher than that of cold processing equipment such as machining. The process is difficult to control, and the energy loss cannot be accurately counted. Therefore, most of the current research objects of production energy-saving scheduling are intermittent machining production equipment, and the research focus is mainly on the switching strategy of machining equipment. The modeling method of flexible job shop energy-saving scheduling considering shutdown and restart strategy, patent CN106020142A proposed a flexible job shop scheduling method considering energy consumption cost, and patent CN104808636A proposed a flexible flow shop energy consumption optimization scheduling method, etc.

It is difficult to accurately calculate the energy consumption of heating furnace equipment in production engineering, resulting in serious energy loss. At the same time, the subsequent continuity of heating furnace equipment processing increases the difficulty of production scheduling. Therefore, it is very valuable to establish an energy loss model for the production process of heating furnace equipment, aiming at the overall energy consumption of heating furnace equipment and processing equipment, and to achieve green manufacturing in the manufacturing process through production scheduling technology.

SUMMARY OF THE INVENTION

The energy-saving scheduling model of the hybrid production workshop considering the continuous processing of the heating furnace established in the present invention aims at green manufacturing and energy-saving production. During the production scheduling, the various states of processing equipment in different manufacturing stages are analyzed, and the optimization function of machining equipment and heating furnace equipment is established with the energy consumption as the goal in production scheduling.

The technical solution adopted in the present invention is an energy-saving scheduling method for a mixed production workshop considering the continuous processing of the heating furnace. In a batch of tasks implemented by the method, the total energy consumption is divided into continuous processing phase energy consumption and intermittent processing phase energy consumption according to different types of processing stages. Stage energy consumption, the continuous processing stage is dominated by heating furnace equipment. Once the heating furnace equipment is turned on until the final processing is completed, it will remain in the heating state. For the equipment in the intermittent processing stage, there are processes such as processing, standby, and power on/off in production. The energy consumption E _a is composed of the operation energy consumption E _e-ope of the batch processing stage, the standby energy consumption E _e-standby , the switching energy consumption E _e-on/off and the heating furnace equipment energy consumption E _f-run of the continuous stage. is the following formula:

E _a =E _e-ope +E _e-standby +E _e-on/off +E _f-run (1)

S1. Establish the energy consumption model of batch processing equipment under various time states

The processing equipment will be in a variety of different states during the production process. Various time factors are used to represent the production process state of the processing equipment, and the energy consumption of the processing equipment in different states is analyzed. The various time factors of the equipment in the batch processing stage are composed of: the processing equipment interval time T ^g , the preparation time ^{Tr , the processing time T p ,} and the adjustment time T ^s . In the preparation time and adjustment time state, the equipment is in the standby state; in the processing time state, the equipment is in the working state; in the processing equipment interval time state, the equipment adopts the switch strategy, and the equipment will have two states: standby and switch state.

1) Operational energy consumption E _e-ope of batch processing stage

For the operating energy consumption of machining equipment in the batch processing stage, it is mainly the energy consumption of the equipment in the normal processing state, which is expressed as:

2) Standby energy consumption E _e-standby in batch processing stage

For the standby energy consumption of a single piece of equipment to process a single workpiece, the energy consumption generated under the standby power is intermittent during the period from the moment when the single piece of equipment completes the processing of the previous workpiece x to the time when the workpiece i starts to prepare. The standby energy consumption E _e-standby in the processing stage consists of three parts: the preparation state of the equipment, the adjustment state of the equipment, and the waiting state of a single equipment between workpieces, which is expressed as follows:

The judgment interval time parameter G _ij indicates whether the equipment is in a standby state when processing two workpieces. If the actual interval time is less than or equal to the balance interval time, the equipment is in a standby state in the interval state, as follows:

Calculate the interval time T _ij ^g of each process of each workpiece on each equipment, for the i-th workpiece to be processed on the j-th processing stage, the x-th workpiece represents the previous i-th workpiece on the equipment. The workpiece number, the interval time is expressed as follows:

Calculate the balancing interval time T _j ^b , which is obtained by calculating the ratio of the energy of the equipment on and off and the standby power of the equipment. The balancing interval time is expressed as follows:

3) Switching machine energy consumption E _e-on/off in batch processing stage;

For the power consumption of the equipment on and off, if the time period before the next workpiece arrives after the processing of a single piece of equipment is completed in the scheduling process is too long, the on-off strategy is selected to save energy, which is expressed as follows:

S2. Establish the energy consumption model of the continuous stage heating furnace equipment under various time states;

The heating process is based on the controller of the heating furnace, and the heating process is set to the following stages according to different time states:

Stage 1: Empty furnace heating, after the set temperature is approached, the controller adjusts the PWM duty cycle to ensure that the furnace temperature is gently close to the set temperature;

Stage 2: Fine-tune the furnace temperature to ensure that the furnace temperature is stably maintained at the set temperature;

Stage 3: The stage of placing the blank and taking out the blank;

Stage 4: The heating stage of the billet, heating to restore the furnace temperature to the set temperature;

Stage 5: The heat preservation stage of the billet, which is stably maintained at the set temperature;

Stage 6: The heating furnace is closed after all the tasks of the workpiece are completed, and the furnace temperature is lowered to room temperature.

Then the energy consumption (E _f-run ) of the heating furnace equipment in the continuous stage is expressed as follows:

表示每台加热炉加热到设定温度需要的空炉加热和空炉保温所消耗的能耗，后半段

表示加热炉炉内有坯料之后，加热这些坯料需要的能耗，其中dr^f，dr^a，dr^p分别代表加热炉通过PWM调节温度中，在空炉加热阶段、稳定炉温阶段和坯料加热阶段的占空比的均值。where the first half of formula (8)

Indicates the energy consumption of empty furnace heating and empty furnace heat preservation required to heat each heating furnace to the set temperature, the second half

Represents the energy consumption required to heat these billets after there are billets in the heating furnace, where dr ^f , ^{dra , dr p respectively} represent the heating furnace temperature adjustment through PWM, in the empty furnace heating stage, the stable furnace temperature stage and the billet heating stage the mean value of the duty cycle.

S3. Constructing the objective function of the energy-saving scheduling model of the hybrid production workshop

Aiming at the mixed production workshop considering the continuous processing of the heating furnace, the types of different processing stages are analyzed, and the energy consumption model of the machining equipment and the heating furnace equipment is established. From the perspective of power consumption, the optimization equation is established as follows:

f=min(R) (9)

s.t.

The symbols used in the mathematical model are as follows:

The invention aims at green manufacturing and energy-saving production, considers the continuous processing stage with heating furnace equipment and the intermittent processing stage of machining equipment, analyzes various states of processing equipment in different manufacturing stages, and constructs heating furnace equipment from opening, The energy change model of heating, taking and unloading processes, etc., establishes the total energy consumption optimization model of heating furnace equipment and machining equipment with energy consumption as the goal in production scheduling. By using this model, the energy-saving scheduling problem of mixed production workshop considering the continuous processing of heating furnace is solved.

Description of drawings

The present invention will be further described below with reference to the accompanying drawings and embodiments.

Figure 1 is a schematic diagram of the process of processing workpieces by the same machining equipment.

Figure 2 is a schematic diagram of the state change process of the heating furnace.

Figure 3 is a flow chart of the implementation of the present invention.

Detailed ways

The energy-saving scheduling model of the hybrid production workshop considering the continuous processing of the heating furnace established in the present invention aims at green manufacturing and energy-saving production. In the production scheduling stage, various states of workpieces and processing equipment in different manufacturing stages are analyzed, and a production scheduling model with energy consumption as the goal in production scheduling of machining equipment and heating furnace equipment is established.

The total energy consumption of a batch of tasks is divided into continuous processing stage energy consumption and intermittent stage energy consumption according to different types of processing stages. The continuous processing stage is dominated by heating furnace equipment. Once the heating furnace equipment is turned on, it will remain in the heating state until the final processing is completed. , for the equipment in the batch processing stage, there are processing, standby, on-off and other states in production, so the total energy consumption is determined by the operation energy consumption E _e-ope of the batch processing stage, the standby energy consumption E _e-standby , and the on-off energy consumption E The energy consumption E _f-run of the furnace equipment in _e-on/off and continuous stages can be described as the following formula:

E _a =E _e-ope +E _e-standby +E _e-on/off +E _f-run (1)

Below in conjunction with accompanying drawing and specific embodiment, the present invention is further described:

Step 1 Establish the energy consumption model of batch processing equipment under various time states

Figure 1 shows the relationship between the process and energy consumption of processing workpieces for the same machining equipment. The processing equipment will be in a variety of different states during the production process. Various time factors are used to represent the production process state of the processing equipment, and the energy consumption of the processing equipment in different states is analyzed. The various time factors of the equipment in the batch processing stage are composed of: the processing equipment interval time (T ^g ), the preparation time (Tr ⁾ , the processing time (T ^p ), and the adjustment time (T ^s ). In the preparation time and adjustment time state, the equipment is in the standby state; in the processing time state, the equipment is in the working state; in the processing equipment interval time state, the equipment adopts the on-off strategy, and the equipment will have two states: standby and on-off state.

1) Operational energy consumption (E _e-ope ) in the batch processing stage

For the operating energy consumption of machining equipment in the batch processing stage, it is mainly the energy consumption of the equipment in the normal processing state, which can be expressed as:

2) Standby energy consumption in batch processing stage (E _e-standby )

For the standby energy consumption of a single piece of equipment processing a single workpiece, it is the energy consumption generated under the standby power during the period from the moment when the equipment completes the processing of the previous workpiece x to the time when the workpiece i starts to prepare. It consists of three parts Composition: the preparation state of the equipment, the adjustment state of the equipment, and the waiting state of the equipment between the workpieces, which are expressed as follows:

The judgment interval time parameter G _ij indicates whether the equipment is in a standby state when processing two workpieces. If the actual interval time is less than or equal to the balance interval time, the equipment is in a standby state in this interval state, as follows:

Calculate the interval time T _ij ^g of each process of each workpiece on each equipment, for the i-th workpiece to be processed on the j-th processing stage, the x-th workpiece represents the previous i-th workpiece on the equipment. The workpiece number, the interval time is expressed as follows:

Calculate the balancing interval time T _j ^b , which is obtained by calculating the ratio of the energy of the equipment on and off and the standby power of the equipment. The balancing interval time is expressed as follows:

3) On-off energy consumption during batch processing (E _e-on/off )

For the power consumption of the equipment on and off, if the time period before the next workpiece arrives after the processing of a single piece of equipment is completed in the scheduling process is too long, the on-off strategy can be selected to save energy, which is expressed as follows:

Step 2 Establish the energy consumption model of the continuous stage heating furnace equipment under various time states

The heating process is mainly based on the controller of the heating furnace, and the heating process is set to the following stages according to different time states:

Stage 1: Empty furnace heating, after the set temperature is approached, the controller adjusts the PWM duty cycle to ensure that the furnace temperature is gently close to the set temperature;

Stage 2: Fine-tune the furnace temperature to ensure that the furnace temperature is stably maintained at the set temperature;

Stage 3: The stage of placing the blank and taking out the blank;

Stage 4: The heating stage of the billet, heating to restore the furnace temperature to the set temperature;

Stage 5: The heat preservation stage of the billet, which is stably maintained at the set temperature;

Final Stage 6: The furnace is turned off after all the workpieces have been heated, and the furnace temperature is lowered to room temperature.

As shown in Figure 2, it is the change process of temperature and energy consumption in different stages of the heating furnace.

Then the energy consumption (E _f-run ) of the heating furnace equipment in the continuous stage can be expressed as follows:

The first half of the formula represents the energy consumption of empty furnace heating and empty furnace heat preservation required for each heating furnace to heat up to the set temperature, and the second half represents the energy consumption after the billet is in the heating furnace, where dr ^f , dr ^a and ^drp respectively represent the average value of the duty cycle in the empty furnace heating stage, the stable furnace temperature stage and the billet heating stage in the furnace temperature adjustment by PWM.

Step 3 Construct the objective function of the energy-saving scheduling model of the hybrid production workshop

Aiming at the mixed production workshop considering the continuous processing of the heating furnace, the types of different processing stages are analyzed, and the energy consumption model of the machining equipment and the heating furnace equipment is established. From the perspective of power consumption, the optimization equation is established as follows:

f=min(R) (9)

s.t.

The symbols used in the mathematical model are as follows:

Claims (2)

1. the energy-saving scheduling method of the hybrid production workshop considering the continuous processing of the heating furnace is characterized by comprising the following steps of: in a batch of tasks implemented by the method, the total energy consumption is divided into continuous processing stage energy consumption and intermittent stage energy consumption according to different types of processing stages, the continuous processing stage is mainly heating furnace equipment which is in a heating state once being started until the final processing is finished, and the equipment in the intermittent processing stage has the states of processing, standby, startup and shutdown and the like in production, so the total energy consumption E_aEnergy consumption by operation of the batch processing stage E_e-opeStandby energy consumption E_e-standbyEnergy consumption for turning on/off the power supply E_e-on/offAnd continuous phase furnace equipment energy consumption E_f-runComposition, described as the following formula:

E_a＝E_e-ope+E_e-standby+E_e-on/off+E_f-run(1)

s1, establishing an energy consumption model of intermittent processing equipment in various time states

The processing equipment can be in various different states in the production process, various different time factors are adopted to represent the production process state of the processing equipment, and the energy consumption of the processing equipment in different states is analyzed; the various time factors of the equipment in the intermittent processing stage are as follows: machining equipment interval time T^gPreparation time T^rMachining time T^pAdjusting the time T^s(ii) a Preparation time and adjustmentIn the time state, the equipment is in a standby state; in the machining time state, the equipment is in a working state; under the processing equipment interval time state, equipment adopts the switching on and shutting down strategy, and equipment will have two kinds of states: standby and power on/off states;

s2, establishing an energy consumption model of the heating furnace equipment in the continuous stage under various time states;

the heating process is set to the following stages according to the state of different time according to the controller of the heating furnace:

stage 1: heating the empty furnace, and after the temperature reaches the set temperature, adjusting the duty ratio of PWM by using a controller to ensure that the furnace temperature is slowly close to the set temperature;

and (2) stage: finely adjusting the furnace temperature to ensure that the furnace temperature is stably kept at a set temperature;

and (3) stage: placing blank and taking out blank;

and (4) stage: a blank heating stage, wherein heating is carried out to enable the furnace temperature to be recovered to a set temperature;

and (5) stage: the blank is stably kept at a set temperature in a heat preservation stage;

and 6: after the heating of the heating furnace is completed, all the workpieces are closed, and the furnace temperature is reduced to room temperature;

the furnace equipment energy consumption of the successive stages (E)_f-run) Is represented as follows:

wherein the first half of equation (8)

The energy consumption consumed by empty furnace heating and empty furnace heat preservation required by heating each heating furnace to the set temperature is shown in the second half section

Represents the energy consumption required for heating the billets after the billets are in the heating furnace, wherein dr^f，dr^a，dr^pRespectively represent the passage of the heating furnaceIn the PWM temperature regulation, the average value of the duty ratio of an empty furnace heating stage, a furnace temperature stabilizing stage and a blank heating stage;

s3, constructing an objective function of the energy-saving scheduling model of the hybrid production workshop

Aiming at a hybrid production workshop considering the continuous processing of a heating furnace, analyzing different processing stage types, and establishing a model of energy consumption of machining equipment and energy consumption of heating furnace equipment; from the viewpoint of power consumption, an optimization equation is established as follows:

f＝min(R) (9)

s.t.

the symbols used in the mathematical model are specifically as follows:

n number of workpieces;

i workpiece number, i ═ 1,2, …, n;

m number of processing stages;

j is the number of the processing stage, j is 1,2, …, m;

x numbering the previous workpiece of the i workpiece on the same machining equipment;

y numbering the next workpiece of the i workpiece on the same machining equipment;

k device numbers in the same phase;

k_jnumber of devices in the j stage;

n_jkthe j stage is a continuous processing stage and represents the k additionThe number of workpieces to be processed by the heating furnace;

D_jD_j0 means that the j-th stage is a continuous processing stage; d_j1 indicates that the j-th stage is a batch processing stage;

the preparation time of the ith workpiece in the jth stage;

the processing time of the ith workpiece in the jth stage;

adjusting time of the ith workpiece in the jth stage;

the interval time of the ith workpiece on the jth stage;

the energy consumption balance time of the ith workpiece in the jth stage;

G_ijjudging interval time parameters of the ith workpiece in the jth stage;

st_ijthe starting time of the ith workpiece on the jth stage;

rt_ijstarting time of preparation time of the ith workpiece in the jth stage;

pt_ijthe machining start time of the ith workpiece in the jth stage;

sut_ijstarting time of adjustment time of the ith workpiece in the jth stage;

et_ijthe end time of the ith workpiece in the jth stage;

heating the ith workpiece on the jth stage for the first-stage full heating time of the furnace;

heating the ith workpiece in a heating furnace at the j stage for adjusting the heating time at the first stage;

heating the ith workpiece in the second stage of the heating furnace in the j stage for the heating time;

the processing power of the equipment at the j stage;

standby power of the device at the j stage;

the startup and shutdown energy consumption of the equipment at the j stage;

dr^paverage duty ratio of the empty furnace heating stage;

dr^astabilizing the mean value of the duty ratio of the furnace temperature stage;

dr^faverage value of duty ratio of blank heating stage;

r total energy consumption required for all manufacturing facilities to produce n workpieces.

2. The hybrid production shop energy-saving scheduling method considering continuous processing of heating furnaces according to claim 1, characterized in that:

1) energy consumption of operation of the batch processing stage E_e-ope

The operating energy consumption of a machining device in the intermittent machining stage, mainly the energy consumption of the device in the normal machining state, is expressed as:

2) standby energy consumption E of the batch processing stage_e-standby

The standby energy consumption of a single device for processing a single workpiece is the energy consumption generated under the standby power, namely the standby energy consumption E of the intermittent processing stage in the period from the time when the single device finishes processing the previous workpiece x to the time when the workpiece i starts to be prepared_e-standbyThe medicine consists of three parts: the preparation state of the equipment, the equipment adjustment state and the waiting state of the single equipment among the workpieces are represented as follows:

determining interval time parameter G_ijWhether the equipment is in a standby state when the equipment is used for processing two workpieces is indicated, if the actual interval time is less than or equal to the balance interval time, the equipment is in the standby state in the interval state, and the following conditions are indicated:

calculating the interval time T of each process of each workpiece on each device_ij ^gFor the ith workpiece to be processed on the jth processing stage, the xth workpiece represents the workpiece number before the ith workpiece on the apparatus, and the interval time represents the following:

calculating the equilibrium Interval time T_j ^bThe balance interval time is obtained by calculating the ratio of the energy of the device for switching on and off to the standby power of the device and is expressed as follows:

3) energy consumption for switching on and off the machine in the intermittent processing stage E_e-on/off；

For the power consumption of the equipment, if the time period before the next workpiece is delivered is too long after the single equipment workpiece is processed in the scheduling process, the power-on and power-off strategy is selected to save energy, which is expressed as follows:

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