Electric heating control method for tobacco drying apparatus

Abstract

This invention relates to the field of tobacco drying technology, specifically providing an electric heating control method for tobacco drying equipment. The aim is to solve the problem of inaccurate heat control in existing tobacco drying equipment using electric auxiliary heating, which affects the drying quality. To this end, the control method of this invention includes: acquiring the tobacco drying stage and dry bulb temperature Tai; comparing the difference between the drying temperature T corresponding to the tobacco drying stage and the dry bulb temperature Tai with a first preset temperature difference Ti. p1 The size; when T - Tai > T p1 At the same time, the electric heating device is activated and operated, and the tobacco drying equipment is controlled to enter a precise temperature control mode. The control method of this invention can balance the heat supply of the heat pump drying device and the electric heating device with the heat demand of the curing barn, achieving precise control of the heat input in the curing barn and improving the curing quality.

Description

Technical Field

[0001] This invention relates to the field of tobacco drying technology, and specifically provides an electric heating control method for tobacco drying equipment. Background Technology

[0002] Flue-cured tobacco is the main material for making cigarettes. The preparation process of flue-cured tobacco is a process of controlling the moisture of tobacco leaves to dehydrate and dry them in a timely manner.

[0003] During the tobacco curing process, heat pump heating is the primary method, supplemented by electric heating. Electric heating is activated as an auxiliary method when the heat pump supply is insufficient. For example, electric heating can be used to increase the heating rate at low ambient temperatures (below 10°C), or electric heating can be used to continue curing if the dryer itself malfunctions and cannot operate.

[0004] Conventional electric heating control methods do not consider the difference between the output heat of the electric heating device and the output heat of the heat pump drying device. The electric heating device is only activated when the heat supply of the heat pump drying device is insufficient. Furthermore, the electric heating device does not have a separate shutdown condition after activation. It works in conjunction with the heat pump drying device to shut down together with the heat pump drying device after the oven temperature reaches the set temperature. As a result, there may be situations where the heat supply required for the oven to heat up is less than the heat provided by both the heat pump drying device and the electric heating device when they are both fully activated. Consequently, even after the heat pump drying device and the electric heating device are shut down, the temperature inside the oven continues to rise, affecting the baking quality.

[0005] In addition, the existing electric heating start-stop mainly relies on detecting the temperature inside the curing room. Since the tobacco leaves inside the curing room are extremely dense, the problem of temperature lag is particularly prominent. At the same time, electric heating has a lot of inertia, and the heat control is not precise enough, which can also affect the curing quality.

[0006] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0007] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem that the heat control is inaccurate when the existing tobacco drying equipment uses electric heating as an auxiliary heat source, which affects the drying quality.

[0008] This invention provides an electric heating control method for a tobacco drying equipment, the tobacco drying equipment including an electric heating device, the control method comprising: acquiring the tobacco roasting stage and dry bulb temperature Tai; comparing the difference between the roasting temperature T corresponding to the tobacco roasting stage and the dry bulb temperature Tai with a first preset temperature difference T. p1 The size; when T-Tai > T p1 At that time, the electric heating device is started and operated, and the tobacco drying equipment is controlled to enter the precise temperature control mode.

[0009] In a specific embodiment of the electric heating control method for the above-mentioned tobacco drying equipment, the control method further includes: acquiring the outdoor ambient temperature Tao; and selectively controlling the electric heating device to shut down based on the outdoor ambient temperature Tao and the drying temperature T.

[0010] In a specific embodiment of the electric heating control method for the aforementioned tobacco drying equipment, the step of "selectively controlling the electric heating device to shut down based on the outdoor ambient temperature Tao and the baking temperature T" specifically includes: comparing the outdoor ambient temperature Tao with a first preset ambient temperature Tao1 and a second preset ambient temperature Tao2; when Tao > Tao1, controlling the electric heating device to shut down; when Tao2 < Tao < Tao1, comparing the baking temperature T with the first preset baking temperature T k1 The size of the oven temperature T is determined, and based on the comparison result, the electric heating device is selectively shut off; when Tao < Tao2, the baking temperature T is compared with the second preset baking temperature T. k2 The size of the electric heating device is determined, and based on the comparison results, the electric heating device is selectively shut down.

[0011] In a specific embodiment of the electric heating control method for the aforementioned tobacco drying equipment, "when Tao2 < Tao < Tao1, the baking temperature T is compared with the first preset baking temperature T". k1 The step of "determining the size of T and selectively controlling the electric heating device to shut down based on the comparison result" further includes: when T < T k1 When T > T, the electric heating device is turned off; k1 At that time, the outlet air temperature T1 is obtained; based on the outlet air temperature T1 and the dry bulb temperature Tai, the electric heating device is selectively controlled to shut down.

[0012] In a specific embodiment of the electric heating control method for the aforementioned tobacco drying equipment, "when Tao < Tao2, the baking temperature T is compared with the second preset baking temperature T". k2 The step of "determining the size of T and selectively controlling the electric heating device to shut down based on the comparison result" further includes: when T < T k2 When T > T, the electric heating device is turned off; k2 At that time, the outlet air temperature T1 is obtained; based on the outlet air temperature T1 and the dry bulb temperature Tai, the electric heating device is selectively controlled to shut down.

[0013] In a specific embodiment of the electric heating control method for the aforementioned tobacco drying equipment, the step of "selectively controlling the electric heating device to shut down based on the outlet air temperature T1 and the dry bulb temperature Tai" specifically includes: comparing the difference between the outlet air temperature T1 and the dry bulb temperature Tai with a second preset temperature difference T. p2 The size; when T1-Tai>T p2 When T1-Tai < T p2 At that time, the internal coil temperature Tc1 is obtained; the difference between the internal coil temperature Tc1 and the outlet air temperature T1 is compared with the third preset temperature difference T. p3 The size; when Tc1-T1>T p3 When Tc1-T1 < T p3 At that time, the difference between the baking temperature T and the dry bulb temperature Tai is compared with the first preset temperature difference T. p1 The size; when T-Tai < T p1 When the electric heating device is turned off, control it to shut down.

[0014] In a specific implementation of the electric heating control method for the above-mentioned tobacco drying equipment, when Tao2 < Tao < Tao1, the control method of the precise temperature control mode specifically includes: controlling the electric heating device to operate at a first heating power.

[0015] In a specific embodiment of the electric heating control method for the aforementioned tobacco drying equipment, when Tao < Tao1, the control method of the precise temperature control mode includes: first controlling the electric heating device to operate at a first heating power; after the electric heating device operates at the first heating power for a second preset time, comparing the difference between the drying temperature T and the outdoor ambient temperature Tai with the first preset temperature difference T. p1 The size, and the difference between the outlet air temperature T1 and the dry bulb temperature Tai and the second preset temperature difference T p2 The size; when T-Tai > T p1 T1-Tai < T p2 When T1-Tai > T p2 At that time, the electric heating device is controlled to maintain operation at the first heating power.

[0016] In a specific embodiment of the electric heating control method for the aforementioned tobacco drying equipment, when Tao < Tao1, the control method of the precise temperature control mode further includes: when the electric heating device is operating at the second heating power, after the electric heating device has been operating at the second heating power for a third preset time, comparing the difference between the drying temperature T and the outdoor ambient temperature Tai with the first preset temperature difference T. p1The size, and the difference between the outlet air temperature T1 and the dry bulb temperature Tai and the second preset temperature difference T p2 Second preset temperature difference T p4 The size; when T-Tai > T p1 T1-Tai < T p2 When T-Tai > T p1 T p2 <T1-Tai<T p4 When T1-Tai > T p4 When the electric heating device is switched to the first heating power, the first heating power is less than the second heating power and the third heating power is less than the third heating power. In a specific embodiment of the electric heating control method for the aforementioned tobacco drying equipment, the control method further includes: acquiring the return air temperature T3; comparing the difference between the return air temperature T3 and the baking temperature T with a fifth preset temperature difference T. p5 The size; when T3-T≥T p5 When the electric heating device is turned off, control it to shut down.

[0017] With the above technical solution, the activation of the electric heating device is determined by the outdoor ambient temperature Tao, the outlet air temperature T1, the baking temperature T, the internal coil temperature Tc1, and the dry bulb temperature Tai, while the deactivation of the electric heating device is determined by the return air temperature T3. By combining temperature monitoring at multiple points to control the on / off state of the electric heating device, a balance can be achieved between the heat supply from the heat pump drying device and the electric heating device and the heat demand of the curing barn. This allows for precise control of the heat input within the curing barn, improving the curing quality. Furthermore, when the heat supply from the heat pump drying device is insufficient, the early intervention of the electric heating device can increase the input heat. Precise control of the electric heating device to operate at different heating powers under different conditions significantly shortens the heating time and improves the quality of tobacco curing. Attached Figure Description

[0018] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0019] Figure 1 This is a flowchart of the main steps of the electric heating control method for the tobacco drying equipment of the present invention;

[0020] Figure 2 This is a flowchart of the steps in Embodiment 1 of the electric heating control method for the tobacco drying equipment of the present invention;

[0021] Figure 3 This is a flowchart illustrating the steps of Embodiment 2 of the electric heating control method for the tobacco drying equipment of the present invention;

[0022] Figure 4 This is a flowchart of the first part of Embodiment 3 of the electric heating control method for the tobacco drying equipment of the present invention;

[0023] Figure 5 This is a flowchart of the steps in the second part of Embodiment 3 of the electric heating control method for the tobacco drying equipment of the present invention. Detailed Implementation

[0024] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0025] It should be noted that although the steps of the control method of the present invention are described in a specific order in the description of the present invention, these orders are not restrictive. Without departing from the basic principles of the present invention, those skilled in the art can perform the steps in different orders.

[0026] The control method of this invention addresses situations where the dry-bulb temperature in the curing chamber drops during the switching of the curing stage and at the end of dehumidification, i.e., at the instant the curing chamber temperature is about to rise. It determines whether to control the tobacco drying equipment to enter a precise temperature control mode based on the outdoor ambient temperature Tao, the outlet air temperature T1, the curing temperature T, the internal coil temperature Tc1, the dry-bulb temperature Tai, and the return air temperature T3. Here, the outlet air temperature T1 is the temperature of the air flowing from the heating chamber through the air inlet to the curing chamber, and the return air temperature T3 is the temperature of the air flowing back from the curing chamber through the return air inlet to the heating chamber.

[0027] First refer to Figure 1 The figure is a flowchart of the main steps of the electric heating control method for the tobacco drying equipment of the present invention.

[0028] Tobacco drying equipment includes heat pump drying units and electric heating units, such as... Figure 1 As shown, the control method of the present invention mainly includes the following steps:

[0029] S1, obtaining the tobacco roasting stage and dry ball temperature Tai;

[0030] S2, compare the difference between the roasting temperature T and the dry-bulb temperature Tai corresponding to the tobacco roasting stage with the first preset temperature difference T. p1 Size;

[0031] S3, when T-Tai > T p1 At that time, the electric heating device is started and running, and the tobacco drying equipment is put into precise temperature control mode.

[0032] In steps S1 and S2, the tobacco roasting process includes a yellowing stage, a color-fixing stage, and a drying stage. Different roasting stages correspond to different roasting temperatures. Those skilled in the art will pre-store the mapping relationship between roasting stages and roasting temperatures T, and then match the corresponding roasting temperature T based on the actual roasting stage of the tobacco.

[0033] The electric heating device of this invention is equipped with six electric heating tubes. Different numbers of heating tubes correspond to different heating powers, thus corresponding to different speed settings. Specifically, when the heating power of the electric heating device is at the first heating power, the heating power is the lowest, with two heating tubes operating (low setting); when the heating power of the electric heating device is at the second heating power, the heating power is in the middle, with four heating tubes operating (medium setting); and when the heating power of the electric heating device is at the third heating power, the heating power is the highest, with all six heating tubes operating (high setting). Of course, the above-mentioned correspondence between heating power, number of heating tubes, and speed settings is merely exemplary, and this invention does not impose any limitations on it.

[0034] The control method of the present invention further includes:

[0035] Obtain the outdoor ambient temperature (Tao);

[0036] The electric heating device is selectively shut down based on the outdoor ambient temperature Tao and the baking temperature T.

[0037] The technical solution of the present invention will be described in detail below with reference to three specific embodiments.

[0038] Example 1

[0039] The following is combined with Figure 2 The technical solution of the first embodiment of the present invention will be described in detail below. For example... Figure 2 As shown, the control method in this embodiment includes the following steps:

[0040] S101, Obtain the outdoor ambient temperature Tao;

[0041] S102, compare the outdoor ambient temperature Tao with the first preset ambient temperature Tao1;

[0042] S103, when Tao > Tao1, control the electric heating device to shut down.

[0043] For example, the first preset ambient temperature Tao1 is 15°C. When the outdoor ambient temperature Tao is higher than 15°C, the heating demand in the drying room can be met by the heat pump drying device alone, without the need to start the electric heating device.

[0044] Example 2

[0045] The following is combined with Figure 3 The technical solution of the second embodiment of the present invention will be described in detail below. For example... Figure 3 As shown, the control method in this embodiment includes the following steps:

[0046] S201, Obtaining the outdoor ambient temperature Tao and the tobacco roasting stage;

[0047] S202, compare the outdoor ambient temperature Tao with the first preset ambient temperature Tao1 and the second preset ambient temperature Tao2;

[0048] S203, when Tao2 < Tao < Tao1, compare the roasting temperature T corresponding to the tobacco roasting stage with the first preset roasting temperature T. k1 Size;

[0049] When T < T k1 When the time comes, proceed to step S210;

[0050] When T>T k1 When the time comes, proceed to step S204;

[0051] S204, obtain the outlet air temperature T1 and dry bulb temperature Tai;

[0052] S205, based on the outlet air temperature T1 and the dry bulb temperature Tai, compare the difference between the outlet air temperature T1 and the dry bulb temperature Tai with the second preset temperature difference T. p2 Size;

[0053] When T1-Tai>T p2 When the time comes, proceed to step S210;

[0054] When T1-Tai < T p2 When the time comes, proceed to step S206;

[0055] S206, obtain the internal coil temperature Tc1;

[0056] S207, compare the difference between the internal coil temperature Tc1 and the outlet air temperature T1 with the third preset temperature difference T. p3 Size;

[0057] When Tc1-T1>T p3 When the time comes, proceed to step S210;

[0058] When Tc1-T1<T p3 When the time comes, proceed to step S208;

[0059] S208, after the tobacco drying equipment has been running for a first preset time, compare the difference between the baking temperature T and the dry bulb temperature Tai with the first preset temperature difference T. p1 Size;

[0060] When T-Tai < T p1 When the time comes, proceed to step S210;

[0061] When T-Tai>T p1 At that time, proceed to step S209;

[0062] S209 controls the electric heating device to start and run, and controls the tobacco drying equipment to enter the precise temperature control mode;

[0063] S210, control the electric heating device to shut down.

[0064] In step S209, the control method for the precise temperature control mode specifically includes:

[0065] S211, control the electric heating device to operate at the first heating power.

[0066] For example, the first preset ambient temperature Tao1 is 15°C, the second preset ambient temperature Tao2 is 10°C, and the first preset baking temperature T k1 The first preset temperature difference is 40℃. p1 The second preset temperature difference is 1℃. p2 The third preset temperature difference is 5℃. p3 The initial temperature is 10℃, and the first preset time is 1 minute. When the outdoor ambient temperature is between 10℃ and 15℃, the baking temperature T is first compared with the first preset baking temperature T. k1 If T < 40℃, the heat pump drying device alone can meet the temperature rise requirements of the drying room, and there is no need to start the electric heating device. If T > 40℃, compare the difference between the outlet air temperature T1 and the dry bulb temperature Tai with the second preset temperature difference T. p2 The difference between the outlet air temperature T1 and the dry bulb temperature Tai indicates whether the actual heat exchange trend in the drying oven can guarantee the heating efficiency. If T1-Tai > 5℃, it indicates that the actual heat exchange trend in the drying oven can guarantee the heating efficiency, and therefore no electric heating device is needed to supplement the heat. Conversely, if T1-Tai < 5℃, it is necessary to compare the difference between the inner coil temperature Tc1 and the outlet air temperature T1 with the third preset temperature difference Tc1. p3 The difference between the inner coil temperature Tc1 and the outlet air temperature T1 indicates whether the heat exchanger can heat the curing room in a short time. If Tc1-T1 > 10℃, it means that the heat exchanger can heat the curing room in a short time, so no electric heating device is needed to supplement the heat. Conversely, if Tc1-T1 < 10℃, after the tobacco drying equipment has been running for 1 minute, that is, after the heat pump drying device has been running for 1 minute, the difference between the curing temperature T and the dry bulb temperature Tai is compared with the first preset temperature difference T. p1The value of the difference between the baking temperature T and the dry-bulb temperature Tai indicates the balance between the heat demand in the curing barn and the heat supplied by the heat pump drying device. If T-Tai < 1℃ after 1 minute of operation of the heat pump drying device, it indicates that the heat demand in the curing barn and the heat supplied by the heat pump drying device have reached a heat balance. In this case, the electric heating device needs to be turned off. Conversely, if T-Tai > 1℃ after 1 minute of operation of the heat pump drying device, it indicates that the balance between the heat demand in the curing barn and the heat supplied by the heat pump drying device cannot be achieved by relying solely on the operation of the heat pump drying device. In this case, in order to shorten the heating time of the curing barn, it is necessary to supplement the heat through the electric heating device, control the tobacco drying equipment to enter the precise temperature control mode, and make the electric heating device operate at a low level to avoid the supplied heat exceeding the demand, thereby affecting the curing quality.

[0067] Example 3

[0068] The following is combined with Figure 4 and Figure 5 The technical solution of the third embodiment of the present invention will be described in detail below. For example... Figure 4 As shown, the control method in this embodiment includes the following steps:

[0069] S301, Obtain the outdoor ambient temperature Tao and the tobacco roasting stage;

[0070] S302, compare the outdoor ambient temperature Tao with the second preset ambient temperature Tao2;

[0071] S303, when Tao < Tao2, compare the baking temperature T with the second preset baking temperature T. k2 Size;

[0072] When T < T k2 When the time comes, proceed to step S310;

[0073] When T>T k2 When the time comes, proceed to step S304;

[0074] S304, obtain the outlet air temperature T1 and dry bulb temperature Tai;

[0075] S305, based on the outlet air temperature T1 and the dry bulb temperature Tai, compare the difference between the outlet air temperature T1 and the dry bulb temperature Tai with the second preset temperature difference T. p2 Size;

[0076] When T1-Tai>T p2 When the time comes, proceed to step S310;

[0077] When T1-Tai < T p2 When the time comes, proceed to step S306;

[0078] S306, obtain the internal coil temperature Tc1;

[0079] S307, compare the difference between the internal coil temperature Tc1 and the outlet air temperature T1 with the third preset temperature difference T. p3 Size;

[0080] When Tc1-T1>T p3 When the time comes, proceed to step S310;

[0081] When Tc1-T1<T p3 When the time comes, proceed to step S308;

[0082] S308, after the tobacco drying equipment has been running for a first preset time, compare the difference between the baking temperature T and the dry bulb temperature Tai with the first preset temperature difference T. p1 Size;

[0083] When T-Tai < T p1 When the time comes, proceed to step S310;

[0084] When T-Tai>T p1 When the time comes, proceed to step S309;

[0085] S309 controls the electric heating device to start and run, and controls the tobacco drying equipment to enter the precise temperature control mode;

[0086] S310, controls the electric heating device to shut down.

[0087] In step S309, as Figure 5 As shown, the control method of the precise temperature control mode specifically includes:

[0088] S311, first control the electric heating device to operate at the first heating power;

[0089] S312, after the electric heating device has been running at the first heating power for a second preset time, compare the difference between the baking temperature T and the outdoor ambient temperature Tai with the first preset temperature difference T. p1 The size, and the difference between the outlet air temperature T1 and the dry bulb temperature Tai, and the second preset temperature difference T p2 Size;

[0090] S313, when T-Tai > T p1 T1-Tai < T p2 At that time, the electric heating device is switched to the second heating power mode;

[0091] S314, when T1-Tai>T p2 At that time, the electric heating device is controlled to maintain operation at the first heating power.

[0092] In step S313, when the electric heating device is operating at the second heating power, the control method for the precise temperature control mode further includes:

[0093] S314, after the electric heating device has been running at the second heating power for a third preset time, compare the difference between the baking temperature T and the outdoor ambient temperature Tai with the first preset temperature difference T. p1 The size, and the difference between the outlet air temperature T1 and the dry bulb temperature Tai, and the second preset temperature difference T p2 Second preset temperature difference T p4 Size;

[0094] S3141, when T-Tai > T p1 T1-Tai < T p2 At that time, the electric heating device is switched to the third heating power mode;

[0095] S3142, when T-Tai > T p1 T p2 <T1-Tai<T p4 At the same time, the electric heating device is controlled to maintain operation at the second heating power;

[0096] S3143, when T1-Tai>T p4 At that time, the electric heating device is switched to the second heating power.

[0097] For example, the second preset ambient temperature Tao2 is 10°C, and the second preset baking temperature T k2 The first preset temperature difference is 30℃. p1 The second preset temperature difference is 1℃. p2 The third preset temperature difference is 5℃. p3 The fourth preset temperature difference is 10℃. p4 The temperature is 10℃, the first preset time is 1 minute, the second preset time is 1 minute, and the third preset time is 1 minute.

[0098] When the outdoor ambient temperature Tao < 10℃, first compare the baking temperature T with the second preset baking temperature T. k2 If T < 30℃, the heat pump drying device alone can meet the temperature rise requirements of the drying room, and there is no need to start the electric heating device. If T > 30℃, compare the difference between the outlet air temperature T1 and the dry bulb temperature Tai with the second preset temperature difference T. p2The difference between the outlet air temperature T1 and the dry bulb temperature Tai indicates whether the actual heat exchange trend in the drying oven can guarantee the heating efficiency. If T1-Tai > 5℃, it indicates that the actual heat exchange trend in the drying oven can guarantee the heating efficiency, and therefore no electric heating device is needed to supplement the heat. Conversely, if T1-Tai < 5℃, it is necessary to compare the difference between the inner coil temperature Tc1 and the outlet air temperature T1 with the third preset temperature difference Tc1. p3 The difference between the inner coil temperature Tc1 and the outlet air temperature T1 indicates whether the heat exchanger can heat the curing room in a short time. If Tc1-T1 > 10℃, it means that the heat exchanger can heat the curing room in a short time, so no electric heating device is needed to supplement the heat. Conversely, if Tc1-T1 < 10℃, after the tobacco drying equipment has been running for 1 minute, that is, after the heat pump drying device has been running for 1 minute, the difference between the curing temperature T and the dry bulb temperature Tai is compared with the first preset temperature difference T. p1 The value of the difference between the baking temperature T and the dry-bulb temperature Tai indicates the balance between the heat demand in the curing barn and the heat supplied by the heat pump drying device. If T-Tai < 1℃ after the heat pump drying device has been running for 1 minute, it indicates that the heat demand in the curing barn and the heat supplied by the heat pump drying device have reached a heat balance. In this case, the electric heating device needs to be turned off. Conversely, if T-Tai > 1℃ after the heat pump drying device has been running for 1 minute, it indicates that the heat demand in the curing barn and the heat supplied by the heat pump drying device cannot be balanced by relying solely on the operation of the heat pump drying device. In this case, in order to shorten the heating time of the curing barn, it is necessary to supplement the heat through the electric heating device and control the tobacco drying equipment to enter the precise temperature control mode.

[0099] After the tobacco drying equipment enters the precise temperature control mode, the electric heating device is initially controlled to run at a low setting. After 1 minute, if T-Tai > 1℃ and T1-Tai < 5℃, it indicates that the heat supply is insufficient to meet the temperature rise requirements of the drying room. The electric heating device is then switched to a medium setting to increase the heat supply. If T1-Tai > 5℃, it indicates that the heat supply is sufficient to meet the temperature rise requirements of the drying room, and the electric heating device continues to operate at a low setting.

[0100] If, after the electric heating device operates at medium speed for 1 minute, T-Tai > 1℃ and T1-Tai < 5℃, it indicates that the electric heating device still cannot meet the heating requirements of the drying room after switching to medium speed. In this case, the electric heating device is switched to high speed to continue increasing the heat supply. If T-Tai > 1℃ and 5℃ < T1-Tai < 10℃, it indicates that the electric heating device can meet the heating requirements of the drying room after switching to medium speed. However, since T1-Tai < 10℃, in order to ensure a continuous and sufficient heat supply, the electric heating device is controlled to continue operating at medium speed. If T1-Tai > 10℃, it indicates that the electric heating device still cannot meet the heating requirements of the drying room after switching to medium speed. In this case, the electric heating device is controlled to switch to high speed to continue increasing the heat supply.

[0101] In Embodiments 2 and 3, the control method of the present invention further includes:

[0102] Obtain the return air temperature T3;

[0103] Compare the difference between the return air temperature T3 and the baking temperature T with the fifth preset temperature difference T. p5 Size;

[0104] When T3-T≥T p5 When the time comes, the electric heating device will be turned off.

[0105] For example, the fifth preset temperature difference T p5 The temperature is 0.5℃. During the operation of the tobacco drying equipment, the return air temperature is monitored. When T3-T≥0.5℃, in order to avoid the temperature in the curing room from continuing to rise due to the inertia of heating, the electric heating device is turned off to ensure the curing quality.

[0106] In addition, in this invention, T-Tai > 1℃ is a prerequisite for the tobacco drying equipment to enter the precise temperature control mode. When T1 < T, the electric heating device needs to be turned on whenever heating is required. When Tc1-T > 5℃ and Tc1-T1 > 10℃, the electric heating device can be turned off.

[0107] This invention provides an electric heating control method for tobacco drying equipment. It uses outdoor ambient temperature Tao, outlet air temperature T1, drying temperature T, internal coil temperature Tc1, and dry bulb temperature Tai to determine whether to activate the electric heating device, and return air temperature T3 to determine whether to deactivate it. By combining temperature monitoring at multiple points to control the activation and deactivation of the electric heating device, it can balance the heat supply from the heat pump drying device and the electric heating device with the heat demand of the curing barn, achieving precise control of heat input within the curing barn and improving curing quality. Furthermore, when the heat supply from the heat pump drying device is insufficient, controlling the electric heating device to intervene earlier can increase the input heat. The method also allows for precise control of the electric heating device to operate at different heating powers according to different conditions, significantly shortening the heating time and improving the quality of tobacco curing.

[0108] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. An electric heating control method for a tobacco drying equipment, characterized in that, The tobacco drying equipment includes an electric heating device, and the control method includes: To obtain the tobacco roasting stage and dry bulb temperature (Tai); The difference between the roasting temperature T corresponding to the tobacco roasting stage and the dry bulb temperature Tai is compared with a first preset temperature difference T. p1 Size; When T-Tai>T p1 At that time, the electric heating device is started and operated, and the tobacco drying equipment is controlled to enter the precise temperature control mode; Obtain the outdoor ambient temperature (Tao); The electric heating device is selectively shut down based on the outdoor ambient temperature Tao and the baking temperature T. The step of selectively controlling the electric heating device to shut down based on the outdoor ambient temperature Tao and the baking temperature T specifically includes: Compare the outdoor ambient temperature Tao with the first preset ambient temperature Tao1 and the second preset ambient temperature Tao2; When Tao2 < Tao < Tao1, compare the baking temperature T with the first preset baking temperature T. k1 The size of the electric heating device is determined, and based on the comparison results, the electric heating device is selectively shut down. When Tao2 < Tao < Tao1, compare the baking temperature T with the first preset baking temperature T. k1 The step of determining the size of the electric heating device and selectively controlling its shutdown based on the comparison results further includes: When T < T k1 When this occurs, the electric heating device is shut off. When T>T k1 At that time, obtain the outlet air temperature T1; The electric heating device is selectively shut down based on the outlet air temperature T1 and the dry bulb temperature Tai.

2. The electric heating control method for the tobacco drying equipment according to claim 1, characterized in that, The step of selectively controlling the electric heating device to shut down based on the outdoor ambient temperature Tao and the baking temperature T further includes: When Tao > Tao1, the electric heating device is turned off. When Tao < Tao2, compare the baking temperature T with the second preset baking temperature T. k2 The size of the electric heating device is determined, and based on the comparison results, the electric heating device is selectively shut down.

3. The electric heating control method for the tobacco drying equipment according to claim 2, characterized in that, When Tao < Tao2, compare the baking temperature T with the second preset baking temperature T. k2 The step of determining the size of the electric heating device and selectively controlling its shutdown based on the comparison results further includes: When T < T k2 When this occurs, the electric heating device is shut off. When T>T k2 At that time, obtain the outlet air temperature T1; The electric heating device is selectively shut down based on the outlet air temperature T1 and the dry bulb temperature Tai.

4. The electric heating control method for tobacco drying equipment according to claim 1 or 3, characterized in that, The step of selectively controlling the electric heating device to shut down based on the outlet air temperature T1 and the dry bulb temperature Tai specifically includes: Compare the difference between the outlet air temperature T1 and the dry bulb temperature Tai with the second preset temperature difference T. p2 Size; When T1-Tai>T p2 When this occurs, the electric heating device is shut off. When T1-Tai < T p2 At that time, obtain the internal coil temperature Tc1; Compare the difference between the inner coil temperature Tc1 and the outlet air temperature T1 with the third preset temperature difference T. p3 Size; When Tc1-T1>T p3 When this occurs, the electric heating device is shut off. When Tc1-T1<T p3 At that time, the difference between the baking temperature T and the dry bulb temperature Tai is compared with the first preset temperature difference T. p1 Size; When T-Tai < T p1 When the electric heating device is turned off, control it to shut down.

5. The electric heating control method for the tobacco drying equipment according to claim 1, characterized in that, When Tao2 < Tao < Tao1, the control method of the precise temperature control mode specifically includes: The electric heating device is controlled to operate at a first heating power.

6. The electric heating control method for the tobacco drying equipment according to claim 2, characterized in that, When Tao < Tao1, the control method of the precise temperature control mode includes: First, control the electric heating device to operate at the first heating power; After the electric heating device operates at the first heating power for a second preset time, the difference between the baking temperature T and the outdoor ambient temperature Tai is compared with the first preset temperature difference T. p1 The size, and the difference between the outlet air temperature T1 and the dry bulb temperature Tai and the second preset temperature difference T p2 Size; When T-Tai>T p1 T1-Tai < T p2 At that time, the electric heating device is controlled to switch to the second heating power operation; When T1-Tai>T p2 At that time, the electric heating device is controlled to maintain operation at the first heating power.

7. The electric heating control method for the tobacco drying equipment according to claim 6, characterized in that, When Tao < Tao1, the control method of the precise temperature control mode further includes: When the electric heating device is operating at the second heating power, after the electric heating device has been operating at the second heating power for a third preset time, the difference between the baking temperature T and the outdoor ambient temperature Tai is compared with the first preset temperature difference T. p1 The size, and the difference between the outlet air temperature T1 and the dry bulb temperature Tai and the second preset temperature difference T p2 Second preset temperature difference T p4 Size; When T-Tai>T p1 T1-Tai < T p2 At that time, the electric heating device is controlled to switch to the third heating power operation; When T-Tai>T p1 T p2 <T1-Tai<T p4 At the same time, the electric heating device is controlled to maintain operation at the second heating power; When T1-Tai>T p4 At that time, the electric heating device is controlled to switch to the first heating power operation; Among them, the first heating power < the second heating power < the third heating power.

8. The electric heating control method for tobacco drying equipment according to any one of claims 1 to 3 and 5 to 7, characterized in that, The control method further includes: Obtain the return air temperature T3; Compare the difference between the return air temperature T3 and the baking temperature T with the fifth preset temperature difference T. p5 Size; When T3-T≥T p5 When the electric heating device is turned off, control it to shut down.

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