Automatic control method and system for output CV of hot air temperature PID controller

Abstract

The invention discloses an output CV automatic control method and system of a hot air temperature PID controller, and the method comprises the steps: calculating the hot air temperature deviation of each stage through the calculated actual set value of the hot air temperature at each stage and the actual temperature value obtained by a hot air temperature sensor; calculating a CV low-limit range and a CV high-limit range of the hot air temperature PID controller in each stage, and taking the CV low-limit range and the CV high-limit range as input values of the hot air temperature PID controller for inputting a minimum CV value and a maximum CV value; and the real-time actual set value, the temperature actual value, the low-limit range and the high-limit range are combined with the state of the manual / automatic conversion condition interface to start or stop running the hot air temperature PID controller so as to output and control the opening degree of the steam membrane valve. The maximum CV control range and the minimum CV control range of the hot air temperature PID controller are limited, so that the control level of the hot air temperature of the shred and leaf moistening machine of the roller equipment is effectively improved, and the moisture and the water flow are controlled by controlling the hot air temperature.

Description

Technical Field

[0001] The invention relates to the technical field of hot air temperature PID controller automatic control, in particular to an output CV automatic control method and system of a hot air temperature PID controller. Background Art

[0002] The working principle of the drum-type hot air moistening machine is as follows: tobacco leaves and shredded tobacco enter the drum-type hot air moistening machine, and its drum continuously drives the material to roll toward the outlet. While moving toward the outlet:

[0003] 1. Through steam injection, it mixes with the added water and atomizes and adds water to the material in the drum;

[0004] Second, saturated steam is sprayed directly into the hot air duct to heat the circulating air. Relying on the power of the circulating fan, the heated hot air is mixed with the material along the hot air duct and the drum to heat and humidify the material to meet the process requirements.

[0005] The function of the drum hot air moistening machine is to increase the temperature and humidity of the materials and make them loose. Only in a high temperature and fast air flow environment can materials such as tobacco and tobacco leaves absorb moisture and increase temperature quickly, fully and evenly.

[0006] At present, the minimum actual opening of the saturated steam valve PID_CV.LL input value of the hot air temperature PID controller of the drum-type hot air silk and leaf moistening machine is 0%, and the maximum actual opening of the steam valve PID_CV.HL input value is 100%. Among them, CV represents the actual opening of the saturated steam valve, LL represents the lower limit range, and HL represents the upper limit range. Refer to the attached Figure 1 In the process of hot air temperature PID controller control, the actual opening of the output saturated steam valve PID.CV output range is 0-100%, and the membrane valve opening control range is 0-100%. Due to the strong hysteresis of hot air temperature control, the hot air temperature is often difficult to control or uncontrollable during operation. The hot air temperature deviation range is large. During the adjustment of the PID controller, the steam injection amount is too much or too little, which directly causes the moisture and temperature of the outlet material to change greatly. The outlet moisture and temperature of the product do not meet the standard, which seriously affects the quality of the product. Summary of the invention

[0007] The object of the present invention is to provide an output CV automatic control method and system of a hot air temperature PID controller, which is used to solve the problem that in the prior art, during the control process of the hot air temperature PID controller, the actual opening output range of the output saturated steam valve is 0-100%, and the opening control range of the membrane valve is 0-100%. Since the hot air temperature control has a strong hysteresis, the hot air temperature is difficult to control or uncontrollable during operation.

[0008] The present invention solves the above problems through the following technical solutions:

[0009] An output CV automatic control method of a hot air temperature PID controller, comprising:

[0010] Step A, according to the input setting value sp' of the hot air circulation temperature in each stage, respectively calculate the actual setting value SP of the hot air temperature in each stage;

[0011] Step B, using the calculated actual set value SP of the hot air temperature at each stage and the actual temperature value PV obtained by the hot air temperature sensor, calculate the hot air temperature deviation x = PV-SP at each stage;

[0012] Step C, according to the input lower limit setting value a of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage, the correction coefficient setting value L of the lower limit range of the actual opening of the saturated steam valve at each stage, and the hot air temperature deviation x of each stage calculated in step B, respectively calculate the lower limit range PID_CV.LL of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage as the input value of the minimum value of the actual opening of the saturated steam valve at the input end of the hot air temperature PID controller;

[0013] Step D, according to the input high limit setting value b of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage, the correction coefficient setting value H of the actual high limit range of the opening of the saturated steam valve at each stage, and the hot air temperature deviation x of different stages calculated in step B, respectively calculate the high limit range PID_CV.HL of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage as the input value of the actual maximum opening of the saturated steam valve at the input end of the hot air temperature PID controller;

[0014] Step E, using the calculated actual set value SP of the hot air temperature at each stage, the actual temperature value PV obtained in real time by the hot air temperature sensor, and the actual lower limit range PID_CV.LL and upper limit range PID_CV.HL of the saturated steam valve opening of the hot air temperature PID controller at each stage; and combining the state of the manual / automatic conversion condition interface obtained, start or stop the operation of the hot air temperature PID controller to output the opening of the steam membrane valve.

[0015] As a further improvement, in step A, the calculation method of the actual set value SP of the hot air temperature is:

[0016] When set in the startup phase, SP1=sp′1+n, where SP1 is the actual set value of the hot air temperature in the startup phase; sp′1 represents the input set value of the hot air circulation temperature in the production phase; and n is the temperature increase in the startup phase.

[0017] When set in the production stage, SP2=sp′2, where SP2 is the actual set value of the hot air temperature in the startup stage; sp′2 represents the input set value of the hot air circulation temperature in the production stage.

[0018] As a further improvement, in step C, the actual opening lower limit range PID_CV.LL of the saturated steam valve of the hot air temperature PID controller at each stage is calculated by:

[0019] When set in the startup phase, the actual opening lower limit range of the saturated steam valve PID_CV.LL1=a1-x1*L1, a1 is the actual opening lower limit setting value of the saturated steam valve in the startup phase, x1 is the hot air temperature deviation in the startup phase, and L1 is the correction coefficient setting value of the actual opening lower limit range of the saturated steam valve in the startup phase;

[0020] When set in the production stage, the actual opening lower limit range of the saturated steam valve PID_CV.LL2=a2-x2*L2, a2 ​​is the actual opening lower limit setting value of the saturated steam valve in the production stage, a1=a2, x2 is the hot air temperature deviation in the production stage, and L2 is the correction coefficient setting value of the actual opening lower limit range of the saturated steam valve in the production stage;

[0021] When set in the tailing stage, the actual lower limit range of the saturated steam valve opening PID_CV.LL3=a3=0, a3 is the actual lower limit setting value of the saturated steam valve opening in the tailing stage, which is equal to 0.

[0022] As a further improvement, in step D, the actual opening upper limit range PID_CV.HL of the saturated steam valve of the hot air temperature PID controller at each stage is calculated, and the specific method includes:

[0023] When set in the startup phase, the actual opening upper limit range of the saturated steam valve PID_CV.HL1 = b1-x1*H1, b1 is the actual opening upper limit setting value of the saturated steam valve in the startup phase, x1 is the hot air temperature deviation in the startup phase, and H1 is the correction coefficient setting value of the actual opening upper limit range of the saturated steam valve in the startup phase.

[0024] When set in the production stage, the actual opening upper limit range of the saturated steam valve PID_CV.HL2=b2-x2*H2, b2 is the actual opening upper limit setting value of the saturated steam valve in the production stage, b2=b1, x2 is the hot air temperature deviation in the production stage, and H2 is the correction coefficient setting value of the actual opening upper limit range of the saturated steam valve in the production stage;

[0025] When set in the tailing stage, the actual upper limit range of the saturated steam valve opening PID_CV.HL3=b3-x3*H3, b3 is the actual upper limit setting value of the saturated steam valve opening in the tailing stage, b3=b2=b1, x3 is the hot air temperature deviation in the tailing stage, x3=x2, H3 is the correction coefficient setting value of the actual upper limit range of the saturated steam valve opening in the tailing stage, H3=H2.

[0026] As a further improvement, when the obtained manual / automatic conversion condition interface is in the "on state", the hot air temperature PID controller is turned on, and the hot air temperature adjustment amount PID_CV is calculated to output the opening of the steam film valve;

[0027] When the obtained manual / automatic conversion condition interface is in "off state", the hot air temperature PID controller is turned off; the hot air temperature PID controller stops running, the steam film valve is closed, and the opening of the output steam film valve is 0.

[0028] As a further improvement, in step E, when the condition interface for manual / automatic conversion is in the "open state", the output control of the opening of the steam membrane valve is adjusted by the hot air temperature PID controller according to the actual opening lower limit range PID_CV.LL-upper limit range PID_CV.HL of the saturated steam valve in each stage.

[0029] At the same time, the present invention also solves the above problems through the following technical solutions:

[0030] An output CV automatic control system of a hot air temperature PID controller is used to implement the output CV automatic control method of a hot air temperature PID controller as described above.

[0031] As a further improvement, the system includes: a hot air temperature PID controller, a manual / automatic conversion condition interface, a steam membrane valve, a hot air temperature sensor and a programmable controller, wherein the hot air temperature PID controller communicates with the manual / automatic conversion condition interface, the steam membrane valve, the hot air temperature sensor and the programmable controller respectively, the hot air temperature sensor is arranged at the circulating air inlet, and the actual temperature value PV is obtained in real time by the hot air temperature sensor and fed back to the hot air temperature PID controller; then the programmable controller calculates the actual set value SP of the hot air temperature at different stages, the hot air temperature deviation x, the actual opening lower limit range value PID_CV.LL of the saturated steam valve, and the actual opening upper limit range value PID_CV.HL of the saturated steam valve, and combines the state of the manual / automatic conversion condition interface to turn on or off the hot air temperature PID controller to control the opening of the steam membrane valve through the output of the hot air temperature PID controller.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] (1) The present invention effectively improves the control level of the hot air temperature of the roller equipment silk moistening and leaf moistening machine by limiting the maximum CV control range and the minimum CV control range of the hot air temperature PID controller, and achieves the production process indicators.

[0034] (2) The maximum and minimum limit ranges of CV of the hot air temperature PID controller of the present invention are adjustable, and the ejected steam is limited, which effectively prevents the temperature from being too high or too low due to the lag of the hot air temperature PID control, improves the stability of the hot air temperature, and also improves the relative stability of the outlet moisture. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the original hot air temperature control trend;

[0036] Figure 2 It is a schematic diagram of the original hot air temperature control process trend at each stage;

[0037] Figure 3 It is a schematic diagram of the hot air temperature control process trend at each stage of the present invention;

[0038] Figure 4 It is a schematic diagram of the control trend of the hot air temperature startup stage of the present invention;

[0039] Figure 5 It is a schematic diagram of the control trend of the upper and lower limit ranges of the hot air temperature production stage of the present invention;

[0040] Figure 6 A logic control diagram of the output CV automatic control of a hot air temperature PID controller of the present invention;

[0041] Figure 7 The present invention is a schematic diagram of the process flow of the output CV automatic control of the hot air temperature PID controller. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0043] The following will be combined Figure 1-7 , a method for automatically controlling the output CV of a hot air temperature PID controller according to an embodiment of the present application is described in detail. It is worth noting that the following embodiments are only used to explain the present application and do not constitute a limitation on the present application.

[0044] Embodiment 1:

[0045] See attached Figure 6-7 , an output CV automatic control method of a hot air temperature PID controller, comprising the following steps:

[0046] A. According to the input setting value sp' of the hot air circulation temperature in the startup phase / production phase, the actual setting value SP of the hot air temperature in the startup phase / production phase is calculated respectively;

[0047] 1.1. When setting at the startup stage, the calculation method of the actual set value SP of the hot air temperature is:

[0048] SP1=sp′1+n, wherein SP1 is the actual setting value of the hot air temperature in the startup phase; sp′1 represents the input setting value of the hot air circulation temperature in the production phase; n is the temperature increase in the startup phase; in this embodiment, n=3°C.

[0049] 1.2. When setting in the production stage, the calculation method of the actual set value SP of the hot air temperature is:

[0050] SP2=sp′2, where SP2 is the actual setting value of the hot air temperature in the startup phase; sp′2 represents the input setting value of the hot air circulation temperature in the production phase.

[0051] B. Calculate the hot air temperature deviation x = PV-SP in the startup phase / production phase by using the calculated actual set value SP of the hot air temperature in the startup phase / production phase and the actual temperature value PV obtained by the hot air temperature sensor;

[0052] The hot air temperature deviation x is variable in the startup phase / production phase and serves as a control variable; x1=PV-SP1, x2=PV-SP2, x1 is the hot air temperature deviation in the startup phase, and x2 is the hot air temperature deviation in the production phase.

[0053] C. According to the set value a of the actual lower limit CV.LL of the saturated steam valve opening of the hot air temperature PID controller in the startup stage / production stage / tailing stage, the correction coefficient set value L of the actual lower limit range of the saturated steam valve opening at different stages, and the hot air temperature deviation x at different stages calculated in step B, the actual lower limit range PID_CV.LL of the saturated steam valve opening of the hot air temperature PID controller at different stages is calculated as the input value of the minimum value of CV at the input end of the hot air temperature PID controller;

[0054] In this embodiment, the actual opening lower limit range PID_CV.LL of the saturated steam valve at different stages of the hot air temperature PID controller is calculated by:

[0055] 3.1. When set in the startup phase, the actual opening lower limit range of the saturated steam valve PID_CV.LL1 = a1-x1*L1, a1 is the actual opening lower limit setting value of the saturated steam valve in the startup phase, x1 is the hot air temperature deviation in the startup phase, and L1 is the correction coefficient setting value of the actual opening lower limit range of the saturated steam valve in the startup phase.

[0056] 3.2. When set in the production stage, the actual lower limit range of the saturated steam valve opening PID_CV.LL2=a2-x2*L2, a2 ​​is the actual lower limit setting value of the saturated steam valve opening in the production stage, a1=a2, x2 is the hot air temperature deviation in the production stage, and L2 is the correction coefficient setting value of the actual lower limit range of the saturated steam valve opening in the production stage.

[0057] 3.3. When set in the tailing stage, the actual lower limit range of the saturated steam valve opening PID_CV.LL3=a3=0, a3 is the actual lower limit setting value of the saturated steam valve opening in the tailing stage, which is equal to 0.

[0058] D. According to the set value b of the actual upper limit CV.HL of the saturated steam valve of the hot air temperature PID controller in the startup stage / production stage / tailing stage, the set value H of the correction coefficient of the actual upper limit range of the saturated steam valve in different stages, and the hot air temperature deviation x in different stages calculated in step B, the actual upper limit range PID_CV.HL of the saturated steam valve of the hot air temperature PID controller in different stages is calculated as the input value of the maximum value CV of the input end of the hot air temperature PID controller;

[0059] In this embodiment, the actual opening upper limit range PID_CV.HL of the saturated steam valve at different stages of the hot air temperature PID controller is calculated by:

[0060] 4.1. When set in the startup phase, the actual opening upper limit range of the saturated steam valve PID_CV.HL1 = b1-x1*H1, b1 is the actual opening upper limit setting value of the saturated steam valve in the startup phase, x1 is the hot air temperature deviation in the startup phase, and H1 is the correction coefficient setting value of the actual opening upper limit range of the saturated steam valve in the startup phase.

[0061] 4.2. When set in the production stage, the actual opening upper limit range of the saturated steam valve PID_CV.HL2 = b2-x2*H2, b2 is the actual opening upper limit setting value of the saturated steam valve in the production stage, b2 = b1, x2 is the hot air temperature deviation in the production stage, and H2 is the correction coefficient setting value of the actual opening upper limit range of the saturated steam valve in the production stage.

[0062] 4.3. When set in the tailing stage, the actual opening upper limit range of the saturated steam valve PID_CV.HL3=b3-x3*H3, b3 is the actual opening upper limit setting value of the saturated steam valve in the tailing stage, b3=b2=b1, x3 is the hot air temperature deviation in the tailing stage, x3=x2, H3 is the correction coefficient setting value of the actual opening upper limit range of the saturated steam valve in the tailing stage, H3=H2.

[0063] E. Use the calculated actual set value SP of the hot air temperature at different stages, the actual temperature value PV obtained by the hot air temperature sensor, and the actual lower limit range PID_CV.LL and upper limit range PID_CV.HL of the saturated steam valve opening of the hot air temperature PID controller at different stages; and combine the status of the manual / automatic conversion condition interface PUSHAUTO to start or stop the operation of the hot air temperature PID controller to output the opening (%) of the controlled steam membrane valve.

[0064] In this embodiment, when the obtained manual / automatic conversion condition interface PUSHAUTO is in the "on state", the hot air temperature PID controller is turned on, and the hot air temperature adjustment amount PID_CV is calculated to output the opening degree (%) of the steam membrane valve for control; the opening degree (%) of the steam membrane valve is adjusted within the range of the lower limit range PID_CV.LL-upper limit range PID_CV.HL of the actual opening degree of the saturated steam valve at different stages of the calculated hot air temperature PID controller, so as to form a hot air temperature PID closed-loop control with a limited range of adjustment amount.

[0065] When the "off state" of the manual / automatic switching condition interface PUSHAUTO is obtained, the hot air temperature PID controller is turned off; the hot air temperature PID controller stops running, the steam film valve is closed, and the opening (%) of the steam film valve is 0.

[0066] Embodiment 2:

[0067] See attached Figure 6 , an output CV automatic control system of a hot air temperature PID controller, used to implement an output CV automatic control method of a hot air temperature PID controller described in Example 1, comprising: a hot air temperature PID controller, a manual / automatic conversion condition interface, a steam film valve, a hot air temperature sensor and a programmable controller, wherein the hot air temperature PID controller communicates with the manual / automatic conversion condition interface, the steam film valve, the hot air temperature sensor and the programmable controller respectively, the hot air temperature sensor is arranged at the circulating air inlet, and the actual temperature value PV is obtained in real time by the hot air temperature sensor and fed back to the hot air temperature PID controller; then the programmable controller calculates the actual set value SP of the hot air temperature at different stages, the hot air temperature deviation x, the actual opening lower limit range value PID_CV.LL of the saturated steam valve, and the actual opening upper limit range value PID_CV.HL of the saturated steam valve, and combines the state of the manual / automatic conversion condition interface PUSH AUTO to turn on or off the hot air temperature PID controller, so as to control the opening (%) of the steam film valve through the output of the hot air temperature PID controller.

[0068] Specific implementation process:

[0069] First, in the startup phase, based on the calculated actual hot air temperature setting value SP and the actual temperature value PV measured by the hot air temperature sensor, the hot air temperature deviation x = (PV-SP) is used as the control variable. The product of the hot air temperature deviation x and the correction coefficient setting value L in the startup phase is used as the lower limit correction variable in the hot air temperature startup phase, and is superimposed on the minimum CV input value of the hot air temperature PID controller to calculate the lower limit range of the hot air temperature PID_CV.LL; the product of the hot air temperature deviation x and the correction coefficient setting value H in the startup phase is used as the upper limit correction variable in the hot air temperature startup phase, and is superimposed on the maximum CV input value of the hot air temperature PID controller to calculate the upper limit range of the hot air temperature PID_CV.HL.

[0070] During the startup phase, the PID_CV adjustment output of the hot air temperature PID controller is limited by the PID_CV.LL lower limit range and the PID_CV.HL upper limit range. The PID_CV adjustment output during the startup phase will be output between the PID_CV.LL lower limit range and the PID_CV.HL upper limit range to control the steam film valve opening. During the startup phase, as the material enters, the time and temperature drop rapidly, and the PID_CV adjustment output will reach the highest point of the PID_CV.HL upper limit range and then output constantly, limiting the amount of steam injection into the circulating hot air duct and eliminating the over-temperature phenomenon of the hot air temperature due to reaction lag during the startup phase.

[0071] Secondly, in the production stage, the hot air temperature deviation x = (PV-SP) is calculated based on the actual hot air temperature setting value SP and the actual temperature value PV obtained by the hot air temperature sensor as the control variable. The product of the hot air temperature deviation x and the correction coefficient setting value L in the production stage is used as the lower limit correction variable of the hot air temperature production stage, and is superimposed on the minimum CV input value of the hot air temperature PID controller as the lower limit range of the hot air temperature PID_CV.LL; the product of the deviation x and the correction coefficient setting value H in the high limit range of the production stage is used as the high limit correction variable of the hot air temperature production stage, and is superimposed on the maximum CV input value of the hot air temperature PID controller as the high limit range of the hot air temperature PID_CV.HL.

[0072] During the production stage, the PID_CV adjustment output of the hot air temperature PID controller is limited by the PID_CV.LL lower limit range and the PID_CV.HL upper limit range. The PID_CV adjustment output during the production stage will be output in the range from the lowest point of the PID_CV.LL lower limit range to the highest point of the PID_CV.HL upper limit range to control the opening of the steam membrane valve. During the production stage, as the material temperature changes, the PID_CV adjustment output will be based on the measured actual material temperature, and will be output in the range between the lowest point of the lower limit range and the highest point of the upper limit range within the calculated output range, limiting the amount of steam injection into the circulating hot air duct and controlling the stability of the hot air temperature during the production stage.

[0073] Finally, when the tailing stage = 0, the hot air temperature PID controller is in operation. The hot air temperature PID_CV adjustment amount will perform hot air temperature PID closed-loop control according to the status of the startup stage and production stage;

[0074] When the tailing stage = 1, the hot air temperature PID controller is in the stopped state. The PID.CV output adjustment amount of the hot air temperature PID controller = 0, the steam film valve is closed, and the steam spraying into the circulating air duct is stopped.

[0075] Embodiment 3:

[0076] See attached Figure 2 , production start-up stage / production stage / tailing stage, original hot air temperature control process trend diagram. Among them, the blue line represents the hot air temperature trend, the gray line represents the moisture trend, and the red line represents the water flow trend; the hot air temperature PID controller of the entire production process is adjusted according to the actual temperature obtained by the temperature sensor. Due to the hysteresis of the actual temperature, the temperature fluctuates greatly, and at the same time, it affects the deviation of the moisture content of the export material accordingly.

[0077] See attached Figure 3, production start-up stage / production stage / tailing stage, hot air temperature control process trend diagram after adopting the output CV automatic control method of a hot air temperature PID controller of Example 1. By adopting an output CV automatic control method of a hot air temperature PID controller, at different production stages, according to the actual temperature actual value PV obtained, the lower limit range PID_CV.LL of the actual opening of the saturated steam valve of the hot air temperature PID controller and the upper limit range PID_CV.HL of the actual opening of the saturated steam valve are calculated, and the overshoot status caused by the lag of the actual temperature value PV of the actual opening of the saturated steam valve of the hot air temperature PID controller is eliminated, so that the hot air temperature trend is smooth, and the moisture trend and water flow trend are also correspondingly smooth. By limiting the maximum CV control range and the minimum CV control range of the hot air temperature PID controller, the control level of the hot air temperature of the roller equipment silk and leaf moistening machine is effectively improved, and the production and manufacturing process indicators and control effects are achieved.

[0078] In a specific embodiment,

[0079] (I) Calculation of the output adjustment amount CV of the hot air temperature PID controller:

[0080] 1) Start-up phase: The time required for the temperature to be adjusted is 6 minutes and 42 seconds.

[0081] 1.1) Equipment control parameters:

[0082] Hot air temperature adjustment value PID_CV of hot air temperature PID controller;

[0083] The correction coefficient setting value of the lower limit range of the actual opening of the saturated steam valve is L1 = 0.9;

[0084] The actual setting value of the hot air temperature SP1 = sp'1 + n = 65 + 3 = 68 ° C;

[0085] The actual temperature value PV obtained by the hot air temperature sensor changes from 67.2℃ to 61.14℃ (when cold tobacco enters), and then to 63.09℃;

[0086] 1.2) Hot air temperature PID controller:

[0087] The actual lower limit setting value of the saturated steam valve opening during the startup phase is a1 = 25%;

[0088] The actual upper limit setting value of the saturated steam valve opening during the startup phase is b1 = 32%;

[0089] 1.3) According to the calculation formula:

[0090] Hot air temperature PID controller

[0091] The actual opening lower limit range of the saturated steam valve PID_CV.LL during the startup phase:

[0092] PID_CV.LL1=a1-x1*L1

[0093] =a1-(PV-SP1)*L1

[0094] =25%-(67.2-68)*0.9

[0095] =25.72%;

[0096] PID_CV.LL1=a1-x1*L1

[0097] =a1-(PV-SP1)*L1

[0098] =25%-(61.14-68)*0.9

[0099] =31.174%;

[0100] The actual opening upper limit range of the saturated steam valve PID_CV.HL during the startup phase:

[0101] PID_CV.HL1=b1-x1*H1

[0102] =b1-(PV-SP1)*H1

[0103] =32%-(67.2-68)*0.9

[0104] =32.72%;

[0105] PID_CV.HL1=b1-x1*H1

[0106] =b1-(PV-SP1)*H1

[0107] =32%-(61.14-68)*0.9

[0108] =38.174%;

[0109] From the above, it can be seen that the actual opening lower limit range of the saturated steam valve PID_CV.LL is adjusted between 25.72%-31.174% during the startup phase, and the actual opening upper limit range of the saturated steam valve PID_CV.HL is adjusted between 32.72%-38.174% during the startup phase.

[0110] The CV range of the hot air temperature PID controller is adjusted between 25.72% and 31.174%, and between 32.72% and 38.174%.

[0111] The actual temperature value PV obtained by the hot air temperature sensor fluctuates within the range of 68-60℃.

[0112] 2) Production stage: 2 hours and 54 minutes.

[0113] 2.1) Equipment control parameters:

[0114] The hot air temperature setting value in the production stage is SP2 = sp'2 = 65°C;

[0115] The actual temperature value PV obtained by the hot air temperature sensor during the production stage was 65.59°C at the highest and 64.44°C at the lowest;

[0116] 2.2) Hot air temperature PID controller:

[0117] The actual lower limit setting value of the saturated steam valve opening during the production stage is a2 = 25%;

[0118] The actual upper limit setting value of the saturated steam valve opening in the production stage is b2 = 32%;

[0119] The correction coefficient setting value of the lower limit range of the actual opening of the saturated steam valve in the production stage is L2 = 1.2;

[0120] 2.3) According to the calculation formula:

[0121] Hot air temperature PID controller

[0122] The actual opening lower limit range of the saturated steam valve PID_CV.LL in the production stage:

[0123] PID_CV.LL2=a2-x2*L2=a2-PV-SP2)*L2

[0124] =25%-(65.59-65)*1.2

[0125] =24.292%;

[0126] PID_CV.LL2=a2-x2*L2=a2-PV-SP2)*L2

[0127] =25%-(64.44-65)*1.2

[0128] =25.672%;

[0129] PID_CV.HL2=b2-x2*H2=b2-(PV-SP2)*H2

[0130] =32%-(65.59-65)*1.2

[0131] =31.292%;

[0132] PID_CV.HL2=b2-x2*H2=b2-(PV-SP2)*H2

[0133] =32%-(64.44-65)*1.2

[0134] =32.672%;

[0135] From the above, it can be seen that the actual opening lower limit range of the saturated steam valve PID_CV.LL is adjusted between 24.16%-25.72% in the production stage, and the actual opening upper limit range of the saturated steam valve PID_CV.HL is adjusted between 31.392%-32.672% in the production stage;

[0136] The CV range of the hot air temperature PID controller is adjusted between 24.16% and 2.672%.

[0137] The hot air temperature deviation is maintained at ±0.5℃.

[0138] 3) Tailings stage:

[0139] The actual opening lower limit range value of the saturated steam valve PID_CV.LL3=a3=0;

[0140] The actual opening upper limit range value of the saturated steam valve PID_CV.HL3=b3-x3*H3, and b3=b2=b1, x3=x2, H3=H2;

[0141] PID_CV.HL3 = PID_CV.HL2,

[0142] The CV range of the hot air temperature PID controller is adjusted between 31.392% and 32.672%.

[0143] The output adjustment amount CV of the hot air circulation temperature PID controller in the tailing stage is 0%.

[0144] 2. Data Analysis

[0145] Collect 100 data points during the entire batch production phase:

[0146] 63.09 65.26 65.59 64.55 65.33 64.53 65.13 65.04 65.09 65.03 63.51 65.29 65.6 64.5 65.46 64.53 65.11 64.99 65.08 64.92 63.78 65.39 65.59 64.41 65.49 64.48 64.97 64.99 65.08 64.04 64.11 65.43 65.55 64.43 65.49 64.6 64.89 64.97 65.03 64.99 64.42 65.52 65.45 64.53 65.44 64.8 64.78 64.99 64.96 64.96 64.62 65.57 65.24 64.67 65.37 65.01 64.83 64.99 64.87 64.41 64.82 65.6 65.1 64.79 65.4 65.16 64.97 64.99 64.87 64.54 64.95 65.59 64.9 64.92 65 65.26 65.11 64.97 64.97 64.36 65.05 65.59 64.79 65.07 64.83 65.28 65.11 65.04 64.99 63.7 65.12 65.59 64.67 65.21 64.62 65.26 65.11 65.04 65.03 63.16

[0147] Standard deviation of hot air circulation temperature during production process = 0.491;

[0148] Average value = 64.933°C;

[0149] Coefficient of variation = standard deviation of production process air temperature / average value of production process air temperature * 100;

[0150] =0.491 / 64.339*100=0.756%;

[0151] Data comparison:

[0152] Process requirements: temperature setting value 65℃±2℃;

[0153] The average temperature of the production process wind = 64.933℃;

[0154] Comprehensive evaluation method for cigarette manufacturing level:

[0155] The lower limit of the coefficient of variation of the hot air temperature of the loose rehumidifier is 0.5%, and the upper limit is 4%. The trend of the indicator is expected to be small;

[0156] The lower limit of the variation coefficient of the hot air temperature of the feeder is 0.5%, and the upper limit is 4%. The indicator trend is expected to be small;

[0157] Hot air temperature variation coefficient = 0.756%;

[0158] 0.5%<0.756%<4%, the coefficient of variation of the hot air temperature of the conditioning machine tends to the lower limit.

[0159] Although the present invention is described herein with reference to the illustrative embodiments of the present invention, the above embodiments are only preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and embodiments, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A method for automatic control of the output CV of a hot air temperature PID controller, characterized in that: include: Step A, according to the input setting value sp' of the hot air circulation temperature in each stage, respectively calculate the actual setting value SP of the hot air temperature in each stage; Step B, using the calculated actual set value SP of the hot air temperature at each stage and the actual temperature value PV obtained by the hot air temperature sensor, calculate the hot air temperature deviation x=PV-SP at each stage, where x is used as the control variable; Step C, according to the input lower limit setting value a of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage, the correction coefficient setting value L of the lower limit range of the actual opening of the saturated steam valve at each stage, and the hot air temperature deviation x of each stage calculated in step B, respectively calculate the lower limit range PID_CV.LL of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage as the input value of the minimum value of the actual opening of the saturated steam valve at the input end of the hot air temperature PID controller; Step D, according to the input high limit setting value b of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage, the correction coefficient setting value H of the actual high limit range of the opening of the saturated steam valve at each stage, and the hot air temperature deviation x of different stages calculated in step B, respectively calculate the high limit range PID_CV.HL of the actual opening of the saturated steam valve of the hot air temperature PID controller at each stage as the input value of the actual maximum opening of the saturated steam valve at the input end of the hot air temperature PID controller; Step E, using the calculated actual set value SP of the hot air temperature at each stage, the actual temperature value PV obtained in real time by the hot air temperature sensor, and the actual lower limit range PID_CV.LL and upper limit range PID_CV.HL of the saturated steam valve opening of the hot air temperature PID controller at each stage; and combining the state of the manual / automatic conversion condition interface obtained, start or stop the operation of the hot air temperature PID controller to output the opening of the steam membrane valve.

2. According to claim 1, a method for automatically controlling the output CV of a hot air temperature PID controller, characterized in that: In step A, the actual setting value SP of the hot air temperature is calculated as follows: When set in the startup phase, SP1=sp′1+n, where SP1 is the actual set value of the hot air temperature in the startup phase; sp′1 represents the input set value of the hot air circulation temperature in the production phase; and n is the temperature increase in the startup phase. When set in the production stage, SP2=sp′2, where SP2 is the actual set value of the hot air temperature in the startup stage; sp′2 represents the input set value of the hot air circulation temperature in the production stage.

3. According to claim 1, the output CV automatic control method of the hot air temperature PID controller is characterized in that: In the step C, the actual opening lower limit range PID_CV.LL of the saturated steam valve of the hot air temperature PID controller at each stage is calculated, and the specific method is: When set in the startup phase, the actual opening lower limit range of the saturated steam valve PID_CV.LL1=a1-x1*L1, a1 is the actual opening lower limit setting value of the saturated steam valve in the startup phase, x1 is the hot air temperature deviation in the startup phase, and L1 is the correction coefficient setting value of the actual opening lower limit range of the saturated steam valve in the startup phase; When set in the production stage, the actual opening lower limit range of the saturated steam valve PID_CV.LL2=a2-x2*L2, a2 ​​is the actual opening lower limit setting value of the saturated steam valve in the production stage, a1=a2, x2 is the hot air temperature deviation in the production stage, and L2 is the correction coefficient setting value of the actual opening lower limit range of the saturated steam valve in the production stage; When set in the tailing stage, the actual lower limit range of the saturated steam valve opening PID_CV.LL3=a3=0, a3 is the actual lower limit setting value of the saturated steam valve opening in the tailing stage, which is equal to 0.

4. According to claim 1, a method for automatically controlling the output CV of a hot air temperature PID controller, characterized in that: In the step D, the actual opening upper limit range PID_CV.HL of the saturated steam valve of the hot air temperature PID controller at each stage is calculated, and the specific method includes: When set in the startup phase, the actual opening upper limit range of the saturated steam valve PID_CV.HL1 = b1-x1*H1, b1 is the actual opening upper limit setting value of the saturated steam valve in the startup phase, x1 is the hot air temperature deviation in the startup phase, and H1 is the correction coefficient setting value of the actual opening upper limit range of the saturated steam valve in the startup phase.

5. The output CV automatic control method of a hot air temperature PID controller according to claim 4, characterized in that: In the step D, the actual opening upper limit range PID_CV.HL of the saturated steam valve of the hot air temperature PID controller at each stage is calculated, and the specific method includes: When set in the production stage, the actual upper limit range of the saturated steam valve opening PID_CV.HL2 = b2-x2*H2, b2 is the actual upper limit setting value of the saturated steam valve opening in the production stage, b2 = b1, x2 is the hot air temperature deviation in the production stage, and H2 is the correction coefficient setting value of the actual upper limit range of the saturated steam valve opening in the production stage.

6. The output CV automatic control method of a hot air temperature PID controller according to claim 5, characterized in that: In the step D, the actual opening upper limit range PID_CV.HL of the saturated steam valve of the hot air temperature PID controller at each stage is calculated, and the specific method includes: When set in the tailing stage, the actual upper limit range of the saturated steam valve opening PID_CV.HL3 = PID_CV.HL2.

7. The output CV automatic control method of a hot air temperature PID controller according to claim 1, characterized in that: In the step E, When the obtained manual / automatic conversion condition interface is "on", the hot air temperature PID controller is turned on, and the hot air temperature adjustment amount PID_CV is calculated to output the opening of the steam film valve; When the obtained manual / automatic conversion condition interface is "off state", the hot air temperature PID controller is turned off; the hot air temperature PID controller stops running, the steam film valve is closed, and the opening of the output steam film valve is 0.

8. The output CV automatic control method of a hot air temperature PID controller according to claim 7, characterized in that: In the step E, when the obtained manual / automatic conversion condition interface is "open state", the output control steam film valve opening is adjusted in the hot air temperature PID controller according to the actual opening lower limit range PID_CV.LL-upper limit range PID_CV.HL of the saturated steam valve at each stage.

9. An output CV automatic control system of a hot air temperature PID controller, characterized in that: Used to implement the output CV automatic control method of a hot air temperature PID controller as described in claim 1.

10. The output CV automatic control system of the hot air temperature PID controller according to claim 9, characterized in that: include: A hot air temperature PID controller, a conditional interface for manual / automatic conversion, a steam film valve, a hot air temperature sensor and a programmable controller, wherein the hot air temperature PID controller communicates with the conditional interface for manual / automatic conversion, the steam film valve, the hot air temperature sensor and the programmable controller respectively, the hot air temperature sensor is arranged at the circulating air inlet, and the actual temperature value PV is obtained in real time by the hot air temperature sensor and fed back to the hot air temperature PID controller; the programmable controller then calculates the actual set value SP of the hot air temperature at different stages, the hot air temperature deviation x, the actual lower limit range value PID_CV.LL of the opening of the saturated steam valve, and the actual upper limit range value PID_CV.HL of the opening of the saturated steam valve, and turns on or off the hot air temperature PID controller in combination with the state of the conditional interface for manual / automatic conversion, so as to control the opening of the steam film valve through the output of the hot air temperature PID controller.

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