CN115597045A - Control method for generating continuous steam - Google Patents

Abstract

The application provides a control method for generating continuous steam, which is applied to a steam generating system, wherein the steam generating system comprises a liquid inlet, a steam outlet, and a liquid pump, a water inlet valve and a steam heater which are connected between the liquid inlet and the steam outlet, and the method comprises the following steps: s1, controlling a liquid pump to work to drive liquid to be conveyed to a steam heater in a heating state from a liquid inlet through a water inlet valve and the liquid pump in sequence; s2, controlling the water inlet valve to alternately work on and off at a preset frequency in the working period of the liquid pump, so that liquid intermittently passes through the water inlet valve, and conveying the liquid passing through the water inlet valve to the steam heater in a pulse type continuous water flow with alternately changed strength after passing through the liquid pump; wherein the pulsed continuous stream of water continuously flows within the steam heater and is at least partially vaporized prior to exiting the steam heater. The control method for generating continuous steam can generate continuous steam with stable quality.

Description

Control method for generating continuous steam

Technical Field

The invention relates to the technical field of steam generation, in particular to a control method for generating continuous steam.

Background

The steam has the characteristics of high temperature, capability of generating a large amount of steam by a small amount of liquid water, good diffusibility and the like, and has wide application prospects in the fields of cleaning, disinfection and sterilization. In the prior art, products for cleaning and sterilizing by steam, such as steam car washers, steam mops, steam sterilizing cabinets, steam irons, garment steamers, etc., have been used.

One steam generation method in the prior art is a method of heating and evaporating water stored in a boiler. The boiler also can be used for the water storage container of heating, and it has water to store in it, adopts modes such as electrical heating or fuel heating to heat the boiler for the water boiling in the boiler produces steam, then exports the steam that produces through transfer piping. Because the mode of boiler water storage heating evaporation is adopted, the water in the boiler needs to be completely heated and boiled, and the steam generation speed is slow. In the prior art, the volume of the boiler is set to be small, and water is added into the boiler again after liquid in the boiler is evaporated so as to accelerate the generation speed of steam. However, the steam generated in this manner is not continuous. On the other hand, the dryness and humidity of the steam generated by the boiler water storage heating mode are difficult to control, and the humidity of the steam is usually high, so that the steam cannot be applied to the condition that the dry steam is required to be used; and because the steam is gas-liquid mixed steam with high humidity, the temperature is difficult to reach high temperature, and the steam is difficult to be applied to the situation that high-temperature steam is needed.

Another steam generation method in the prior art is a continuous heater method. Chinese patent application publication No. CN110382953A discloses a method for operating a steam generating apparatus, which employs a continuous heater into which liquid is continuously fed to be heated and evaporated. However, the solution of heating and generating steam by using a continuous heater has high requirement on the thermal efficiency of the continuous heater, otherwise it is difficult to evaporate the liquid to generate steam in a short time, resulting in high humidity of the generated steam. Moreover, as the continuous water inlet time is increased, the temperature of the continuous heater is reduced, so that the quality of the generated steam is inconsistent at different stages in the long-time operation process, and the quality stability of the generated steam is poor.

The chinese patent application publication No. CN102454975A proposes a scheme of intermittently turning on and off the water inlet by frequently turning on and off the water pump, aiming at the problem of insufficient steam temperature caused by insufficient water heating due to too low vaporization temperature, so as to avoid the situation of too low vaporization temperature or to raise the vaporization temperature back to normal as soon as possible after the occurrence of the situation. However, the water pump intermittently opens and closes the water inlet, and the following defects exist: 1) The resistance of the water pump at the beginning of starting is large, the starting current of the water pump is large, frequent starting and closing inevitably affects the service life of the water pump, and when the starting and stopping frequency is too high, the corresponding requirements are difficult to achieve by the existing water pump manufacturing technology; 2) The water inlet is discontinuous, and when the discontinuous time is longer, the generated steam is also discontinuous and discontinuous; 3) Because its intaking is discontinuous, consequently can't provide continuous water pressure, in the time quantum of not intaking, the steam that produces in the vaporization chamber just can lead to the water pump department through the pipeline between water pump and the vaporization chamber against the current, so lead to on the one hand the water pump to be heated, the water pump resistance is big once more opened, has aggravated the damage of water pump, and on the other hand makes steam outlet exhaust steam present obvious strong and weak discontinuity, can't produce continuous, stable steam.

In view of the above, a new technical solution is needed to solve the above problems in the prior art.

Disclosure of Invention

The application provides a control method for generating continuous steam, which can generate continuous steam with stable and controllable quality.

The application is realized by the following technical scheme: a control method for generating continuous steam is applied to a steam generating system, the steam generating system comprises a liquid inlet, a steam outlet, and a liquid pump, a water inlet valve and a steam heater which are connected between the liquid inlet and the steam outlet, and the water inlet valve and the liquid pump are sequentially connected between the liquid inlet and the steam heater, and the control method comprises the following steps:

s1, controlling the liquid pump to work to drive liquid to sequentially pass through the water inlet valve and the liquid pump from the liquid inlet and be conveyed to the steam heater in a heating state;

s2, controlling the water inlet valve to alternately work on and off at a preset frequency in the working period of the liquid pump, so that the liquid intermittently passes through the water inlet valve, and the liquid passing through the water inlet valve is conveyed to the steam heater through a pulse type continuous water flow with alternately changed strength after passing through the liquid pump;

wherein the pulsed continuous stream of water continuously flows within the steam heater and is at least partially vaporized prior to exiting the steam heater.

Optionally, at least a portion of the conduit between the fill valve and the liquid pump proximate the liquid pump is a liquid-filled filling segment.

Optionally, the control method further includes: s3, controlling the steam heater to heat, and detecting the actual temperature of the steam heater; and when the actual temperature of the steam heater reaches the preset temperature, executing the steps S1 and S2.

Optionally, the steam outlet has an open state and a closed state, and in the closed state of the steam outlet, the control method includes: and controlling the steam heater to be in a heating state, and controlling the liquid pump to intermittently work so as to intermittently feed water into the steam heater.

Optionally, the frequency of the intermittent operation of the liquid pump is less than the preset frequency of the on-off alternate operation of the water inlet valve.

Optionally, the controlling the steam heater to be in a heating state and the liquid pump and the water inlet valve to intermittently work to intermittently feed water into the steam heater includes:

controlling the steam heater to work and detecting the working state of the steam heater, controlling the liquid pump and the water inlet valve to work to feed water into the steam heater when the working state of the steam heater reaches a preset condition, and controlling the liquid pump and the water inlet valve to stop feeding water into the steam heater when the working state of the steam heater does not reach the preset condition.

Optionally, the reaching of the preset condition by the operating state of the steam heater includes that the actual temperature of the steam heater reaches a preset temperature.

Optionally, the control method includes: when the steam pressure in the steam generation system reaches a preset value, the steam is discharged through the pressure release valve to release the pressure.

Optionally, the liquid pump is an electromagnetic pump and the water inlet valve is a solenoid valve.

Optionally, the control method is used for generating at least one preset dry-humidity state steam, and the preset dry-humidity state steam is realized by controlling the on-off alternating working preset frequency of the water inlet valve.

The control method for generating continuous steam provided by the application controls liquid to be conveyed to a steam heater in a heating state in a pulse type continuous water flow with strength change, wherein the pulse type continuous water flow continuously flows in the steam heater and is at least partially evaporated and vaporized before flowing out of the steam heater. In the control method provided by the application, water is fed in a pulse type continuous water flow mode with strength change of water flow, so that the steam generation speed is high, and the generated steam is continuous and stable and controllable in quality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a perspective view of a steam generation system to which the control method of the present application is applied.

Fig. 2 is a flowchart of an embodiment of a control method of the present application.

Fig. 3 is a flow chart of water inlet control when the steam outlet is in a closed state according to an embodiment of the control method of the present application.

Fig. 4 is an exploded perspective view of an embodiment of a steam heater of a steam generating system to which the control method of the present application is applied.

Description of reference numerals: 1-a liquid inlet; 2-a steam outlet; 3-a liquid pump; 4-a water inlet valve; 5-a steam heater; 11-a heating device; 111-a heat-generating tube; 1111-a first electrical connection; 1112-a second electrical connection; 112-steam tubes; 1121-water inlet; 1122-a vapor outlet; 113-a heater base; 1132 — a first via; 1133 — a second via; 1134 — first perforation; 1135 — second perforation; 115-mounting holes; 1151-a first mounting hole; 1152-a second mounting hole; 14-a temperature sensor; 141-a first temperature sensor; 142-second temperature sensor.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present application, but are merely examples of apparatus and methods consistent with certain aspects of the present application.

A control method for generating continuous steam according to the present application will be described in detail with reference to the accompanying drawings. The features in the embodiments described below may be combined with each other without conflict.

Referring to fig. 1 to 4, the present application provides a control method for generating continuous steam, which is applied to a steam generating system. Fig. 1 is a schematic diagram of one embodiment of a steam generation system to which the control method for generating continuous steam according to the present invention is applied. In the present embodiment, the steam generating system includes a liquid inlet 1, a steam outlet 2, and a liquid pump 3, a water inlet valve 4 and a steam heater 5 connected between the liquid inlet 1 and the steam outlet 2, wherein the water inlet valve 4 and the liquid pump 3 are connected between the liquid inlet 1 and the steam heater 5 in sequence. The liquid inlet 1, the water inlet valve 4, the liquid pump 3, the steam heater 5 and the steam outlet 2 are connected through pipelines, liquid enters from the liquid inlet 1, enters the steam heater 5 through the water inlet valve 4 and the liquid pump 3, is heated and evaporated into steam, and then is discharged through the steam outlet 2.

The liquid pump 3, i.e. a water pump, is used for providing power for driving liquid to flow, so as to realize control of water intake or stopping water intake, and in an embodiment, the liquid pump 3 is an electromagnetic pump. The water inlet valve 4 is used for controlling the water inflow and the water inlet mode, and in one embodiment, the water inlet valve 4 is a solenoid valve. The liquid pump 3 is connected between the water inlet valve 4 and the steam heater 5, the liquid pump 3 generates pressure to drive liquid to flow into the steam heater 5 when in work, and the water outlet end of the liquid pump 3 is directly connected with the steam heater 5, so the generated pressure is enough to overcome the pressure in a pipeline at the end, connected with the liquid pump 3, of the steam heater 5 so as to avoid reverse flow; and the liquid pump 3 is arranged between the water inlet valve 4 and the steam heater 5, so that the water inlet valve 4 is protected from the pressure from the steam heater 5, and the service life and the stability of the working performance of the water inlet valve 4 are ensured. The liquid pump 3 and the water inlet valve 4 are controlled by related signals to ensure the linkage matching of the work of the two.

Referring to fig. 2, the control method includes: s1, controlling the liquid pump 3 to work to drive liquid to be conveyed from the liquid inlet 1 to the steam heater 5 in a heating state through the water inlet valve 4 and the liquid pump 3 in sequence; s2, controlling the water inlet valve 4 to alternately work on and off at a preset frequency in the working period of the liquid pump 3, so that the liquid intermittently passes through the water inlet valve 4, and the liquid passing through the water inlet valve 4 is conveyed to the steam heater 5 by pulse type continuous water flow with alternately changed intensity after passing through the liquid pump 3; wherein the pulsed continuous water flow is continuously flowing inside the steam heater 5 and at least partially vaporized before flowing out of the steam heater 5.

The application provides a control method, through forming the water inlet mode that has the continuous rivers of the pulsed of strong and weak alternation, make steam heater 5 at strong and weak rivers alternation's in-process, can in time, rapid heating up to the equilibrium temperature that can produce the stable quality steam, realize that steam heater 5's temperature floats near the temperature that can produce preset steam quality all the time, thereby when guaranteeing that the rivers of every pulse period enter steam heater 5, steam heater 5's self state all is the same or almost the same, can not lead to the temperature to descend because of the evaporation heat absorption of the rivers of the place ahead, thereby its steam that produces can be the less dry steam of humidity, and steam is continuous, the stable controllable quality.

In the control method provided by the application, because the water inlet valve 4 is in on-off operation, the instantaneous water flow passing through the water inlet valve 4 is intermittent water flow; after passing through the water inlet valve 4, water flow enters the liquid pump 3 through a pipeline between the water inlet valve 4 and the liquid pump 3, the water flow passing through the liquid pump 3 is modulated into continuous water flow with strength change, and is not intermittent, so that the problems of steam discontinuity and steam countercurrent existing when the water flow enters the steam heater 5 intermittently can be avoided. In this embodiment, the pipeline between the water inlet valve 4 and the liquid pump 3 is filled with liquid, and during the operation of the liquid pump 3, the water inlet valve 4 is switched to operate alternately, so that the liquid between the liquid pump 3 and the water inlet valve 4 is in two alternate environmental states, that is, a state where the liquid pump 3 is on and the water inlet valve 4 is also on, and a state where the liquid pump 3 is on and the water inlet valve 4 is off. In a state where the liquid pump 3 is opened and the water inlet valve 4 is also opened, the liquid between the liquid pump 3 and the water inlet valve 4 is in a state where both ends are open, and the driving force provided by the liquid pump 3 can discharge a certain amount of liquid between the liquid pump 3 and the water inlet valve 4 to the steam heater 5 through the liquid pump 3, and at the same time can draw the liquid from the liquid inlet 1 into a space between the liquid pump 3 and the water inlet valve 4 through the water inlet valve 4. In this state, since the liquid between the liquid pump 3 and the water inlet valve 4 is in a state that both ends are unblocked, the liquid pump 3 drives the liquid to flow into the steam heater 5 with a large water inflow, and a strong water flow part in the pulse type water flow with the variable intensity is formed. When the liquid pump 3 is on and the water inlet valve 4 is off, the upstream of the liquid between the liquid pump 3 and the water inlet valve 4 is off, the liquid between the liquid pump 3 and the water inlet valve 4 is in a relatively closed environment at the moment, the negative pressure needs to be overcome when the liquid pump 3 drives the liquid to flow to the steam heater 5, the water inlet quantity of the liquid pump 3 driving the liquid to flow to the steam heater 5 is smaller at the moment, and the weak water flow part in the pulse type water flow with the variable strength is formed. When the water inlet valve 4 is repeatedly opened and closed at a preset frequency, the water flow passing through the liquid 3 is continuously pulse-type water flow with strength change, and is conveyed to the steam heater 5. By adopting the scheme, the water inlet into the steam heater 5 is continuous, and a small amount of water can generate a large amount of steam, so that the generated steam cannot have obvious interruption or be in a state of large time or small time after passing through the pipeline and the steam nozzle, and the generated steam is continuous and stable.

In another embodiment, the portion of the conduit between the inlet valve 4 and the liquid pump 3 near the liquid pump 3 is a filling segment filled with liquid. That is, the pipe between the feed valve 4 and the liquid pump 3 may not be completely filled with liquid, but may be filled with liquid at a section near the liquid pump 3. In the arrangement of the components of the steam generating system, the position of the water inlet valve 4 can be arranged higher than the position of the liquid pump 3, the water inlet valve 4 is connected in the pipeline between the water inlet valve 4 and the liquid pump 3, the lower half part of the water inlet valve is a filling section filled with liquid, and the upper half part of the water inlet valve can be empty. When the water inlet valve 4 is in on-off alternate work, liquid drops to the filling section in a section through the water inlet valve 4, and the liquid pump 3 is in a continuous water state during work, so that the liquid pump 3 is prevented from being pumped in an empty mode.

In an embodiment of the present invention, the control method for generating continuous steam further comprises: s3, controlling the steam heater 5 to heat, and detecting the actual temperature of the steam heater; when the actual temperature of the steam heater 5 reaches the preset temperature, the steps S1 and S2 are performed.

In this embodiment, the steam heater 5 is preheated, and the inlet water is controlled when the preheating reaches a predetermined temperature, so that the inlet water can be ensured to generate steam with a predetermined quality. Compared with the scheme that the heater is triggered to heat through water inlet in the prior art, the problem that the quality of the early-stage steam is unstable when the steam is discharged can be avoided, and the waste of water resources can be reduced. In the embodiment, the steam quality includes the humidity of the steam, and the preset temperature is set in relation to the water inflow controlled by the liquid pump 3 and the water inlet valve 4 and the humidity of the steam to be achieved. Under the condition that the water inflow is controlled to be constant through the liquid pump 3 and the water inlet valve 4, the drier steam (namely, the steam with lower humidity) is pre-generated, the higher the preset temperature value of the steam heater 5 is, and on the contrary, the wetter steam (namely, the steam with higher humidity) is pre-generated, the lower the preset temperature value of the steam heater 5 is. Further, in this embodiment, the controller automatically triggers the liquid pump 3 and the water inlet valve 4 to feed water according to the detected actual temperature of the steam heater 5, so that accurate water inlet control can be realized, unstable steam quality caused by too early water inlet is avoided, and overheating of the steam heater 5 caused by too late water inlet is avoided.

Referring to fig. 3, in an embodiment that is further improved on the basis of the embodiment of the control method shown in fig. 2, the steam outlet 2 has an open state and a closed state, and when the steam outlet 2 is in the closed state, the control method includes: controlling the steam heater 5 to be in a heating state, and controlling the liquid pump 3 and the water inlet valve 4 to intermittently work so as to intermittently feed water into the steam heater 5.

In a specific embodiment, the open state and the closed state of the steam outlet 2 are manually controlled by a user, so that the user can control the turning-off and discharging of the steam at any time. For example, in one embodiment, the liquid is vaporized into steam in the steam heater 5, and then is connected to a gun head held by a user through a steam pipeline, the gun head is provided with a trigger, and the user can grip and release the trigger to switch the opening state and the closing state of the steam outlet 2.

In the embodiment shown in fig. 3, when the steam outlet 2 is in the closed state, the steam generated in the steam generating system cannot be discharged through the steam outlet 2, and if a large amount of steam is continuously generated, the pressure in the steam generating system is too high, which affects the safety of the steam generating system and the user. In this embodiment, when the steam outlet 2 is in a closed state, the steam heater 5 is controlled to be in a heating state, and the liquid pump 3 and the water inlet valve 4 are controlled to intermittently operate to intermittently feed water to the steam heater 5. So set up have following beneficial effect: the steam heater 5 is controlled to be still in a heating state, so that the steam can be timely generated when a user opens the steam outlet 2. Because a user often needs to frequently turn on and off the steam when using the steam generating system, when the steam outlet 2 is in a closed state, if the steam heater 5 is controlled not to heat any more at this time, the temperature of the steam heater 5 is reduced, when the time when the steam outlet 2 is in the closed state is longer, the temperature of the steam heater 5 is reduced more, and when the user turns on the steam outlet 2 again, the steam generated at this time cannot reach the preset quality. For example, in the dry cleaning process of the laundry using the relatively dry steam, the user closes the steam outlet 2 for a certain period of time and then opens the steam outlet 2 again, and the humidity of the generated steam is relatively high due to the temperature decrease of the steam heater 5, thereby wetting the laundry. On the other hand, because the steam heater 5 is controlled to be still in a heating state, a large amount of steam can be generated by continuously feeding water, so that the pressure in the steam generating system is too high, and the safety of the steam generating system and a user is influenced; if the liquid pump 3 and the water inlet valve 4 are controlled not to feed water, the temperature of the steam heater 5 is continuously increased, which causes overheating. Based on this, in the present embodiment, on the premise that the steam heater 5 is controlled to be in the heating state, the liquid pump 3 and the water inlet valve 4 are controlled to intermittently operate to intermittently feed water to the steam heater 5. So set up, both avoided continuing that a large amount of steam that the intaking produced is difficult to the exhaust problem, avoided steam heater 5 to rise temperature continuously again, caused the overheated problem of dry combustion method.

Further, the controlling the steam heater 5 to be in a heating state and the liquid pump 3 and the water inlet valve 4 to intermittently work to intermittently feed water into the steam heater 5 comprises: controlling the steam heater 5 to work and detecting the working state of the steam heater, controlling the liquid pump 3 and the water inlet valve 4 to work to feed water into the steam heater 5 when the working state of the steam heater 5 reaches a preset condition, and controlling the liquid pump 3 and the water inlet valve 4 to stop feeding water into the steam heater 5 when the working state of the steam heater 5 does not reach the preset condition. Namely, the intermittent water inlet process control is automatically triggered by the controller according to the detected working state of the steam heater 5, so that the working state of the steam heater 5 can be well controlled and maintained, the actual working state of the steam heater 5 is prevented from excessively deviating from the working state when the steam heater can generate steam with preset quality, and the quality-controllable steam is ensured to be generated at any time. The working state reaching the preset condition can be one or more of reaching preset time, preset pressure and preset temperature. Preferably, in an embodiment, the reaching of the preset condition of the operating state of the steam heater 5 includes that an actual temperature of the steam heater 5 reaches a preset temperature. That is, when the steam outlet 2 is in a closed state, whether water is fed or not is controlled by the temperature of the steam heater 5, when the temperature of the steam heater 5 reaches a preset temperature, water is fed by controlling the liquid pump 3 and the water inlet valve 4, and at the moment, the temperature of the steam heater 5 is reduced to be lower than the preset temperature, and the liquid pump 3 and the water inlet valve 4 stop feeding water; and when the temperature of the steam heater 5 is increased to the preset temperature again, controlling the liquid pump 3 and the water inlet valve 4 to feed water again, and repeating the steps to realize intermittent water feeding. In the intermittent water inlet process, water inlet and water inlet stopping are mainly realized by the liquid pump 3, and the water inlet valve 4 is mainly used for realizing a pulse type continuous water flow water inlet mode in a water inlet stage. In other words, the frequency of the intermittent operation of the liquid pump 3 and the water inlet valve 4 is less than the preset frequency of the on-off alternate operation of the water inlet valve 4, that is, in an intermittent water inlet process, the water inlet valve 4 still has a process of multiple on-off alternate operations.

As can be seen from the above description, although the intermittent water feeding can avoid generating a large amount of steam, the steam still can be generated. Therefore, further, in this embodiment, the steam generation system further includes a pressure relief valve, and the control method further includes: when the steam pressure in the steam generation system reaches a preset value, the steam is discharged through the pressure release valve to release the pressure.

When the steam outlet 2 is in an open state, the control method comprises the following steps: controlling the steam heater 5 to be in a heating state, and controlling the liquid pump 3 and the water inlet valve 4 to work to feed water; and the heating of the steam heater 5 and the water inlet relationship controlled by the liquid pump 3 and the water inlet valve 4 are configured such that the heat generated by the steam heater 5 per unit time is not less than the heat consumed by the water inlet controlled by the liquid pump 3 and the water inlet valve 4 per unit time.

That is, when the steam outlet 2 is opened, the liquid is controlled to continuously feed water into the steam heater 5 to ensure the continuity of the generated steam. In order to avoid the temperature drop of the steam heater 5 in the state of continuous water intake, the heat generated by the steam heater 5 in unit time is not less than the heat consumed by the water intake controlled by the liquid pump 3 and the water inlet valve 4 in unit time, so that the steam heater 5 can be heated to a preset temperature from a temperature below the preset temperature in the process of continuous water intake, and can be maintained at the preset temperature after being heated to the preset temperature. The preset temperature may be a temperature interval, the heating to the preset temperature may be heating to a lower limit temperature value of the temperature interval, and the maintaining at the preset temperature may be temperature floating between an upper limit temperature value and a lower limit temperature value of the temperature interval. It should be noted that the continuous water supply is described herein with respect to the intermittent water supply in which the steam outlet 2 is closed, and it should be understood that the continuous water supply and the intermittent water supply are described herein as the manner of supplying the pulsed water flow controlled by the water supply valve 4 is not changed in terms of the continuous on and the intermittent on and off of the liquid pump 3.

The control method for generating continuous steam can be used for generating steam in one or more preset dry-humidity states, and the steam in the preset dry-humidity state is realized by controlling the preset frequency of the on-off alternate work of the water inlet valve 4. For example, when the water inlet valve 4 is controlled to perform on-off alternate operation at a first preset frequency, the liquid passing through the water inlet valve 4 is conveyed to the steam heater 5 at a first preset temperature in a strong and weak pulse type continuous water flow to generate a first dry-humidity steam; when the water inlet valve 4 is controlled to alternately work at a second preset frequency, the liquid passing through the water inlet valve 4 is conveyed to a steam heater 5 at a second preset temperature in a strong and weak pulse type continuous water flow to generate second dry humidity steam; the first preset frequency is different from the second preset frequency, and/or the first preset temperature is different from the second preset temperature, so that the fact that the humidity of the first dry humidity steam is different from the second dry humidity steam can be achieved.

Please refer to fig. 4, which is a perspective exploded view of an embodiment of a steam heater 5 of a steam generating system applied in the control method of the present application. In the present embodiment, the steam heater 5 includes a heating device 11 and a heat-insulating casing (not shown) surrounding the heating device 11. The heating device 11 comprises a heating tube 111 and a steam tube 112, the heating tube 111 is connected with the steam tube 112 in a heat conduction manner, and the outlet of the liquid pump 3 is communicated with the water inlet 1121 of the steam tube 112. As shown in fig. 4, in the present embodiment, the heating device 11 further includes a heater base 113, the heater base 113 is made of a heat conducting material, the heating pipe 111 and the steam pipe 112 are embedded in the heater base 113, and the heating pipe 111 and the steam pipe 112 conduct heat through the heater base 113. Of course, in other embodiments, the heat generating tubes 111 and the steam tubes 112 may also transfer heat by direct contact heat transfer or other means.

Further, as shown in fig. 4, in the present embodiment, the steam heater 5 further includes a temperature sensor 14, the temperature sensor 14 is disposed on the heater base 113, and the temperature sensor 14 is in electrical signal connection with the controller to transmit the temperature information of the heating device 11 to the controller.

Specifically, in the steam heater 5 of the present embodiment, the heater base 113 is used to transfer heat between the heating tube 111 and the steam tube 112, that is, the heat generated by the heating tube 111 is firstly transferred to the heater base 113, and then the heat is transferred to the steam tube 112 by the heater base 113, so that the steam tube 112 is heated uniformly and the temperature is raised rapidly. Moreover, because the heating tube 111 and the steam tube 112 are embedded in the heater base 113, the heating tube 111, the steam tube 112 and the heater base 113 are in close contact with each other, so that the three have good heat-conducting performance, and the heat loss in the heat-conducting process is reduced. Meanwhile, by providing the temperature sensor 14 on the heater base 113, the temperature of the steam can be accurately controlled by the temperature sensor 14, and thus the dryness and humidity of the steam can be controlled. Because the heating tube 111 is a heating source, the temperature of the heating tube is higher than the temperature of the steam, and the temperature of the heating tube cannot represent the temperature of the steam; however, since water flows through the steam pipe 112, the temperature of each portion of the steam pipe 112 is not uniform, and thus the temperature sensor 14 cannot be installed on the heat generating pipe 111 or the steam pipe 112, otherwise the temperature detection value is inaccurate. This steam heater 5 not only heat-conduction efficiency is high, and steam produces fastly, and steam pipe 112 is heated evenly moreover, can guarantee the production quality of steam, and temperature homogeneity, the humidity homogeneity such as steam are better, can control the temperature and the humidity of steam simultaneously.

Specifically, in the present embodiment, the heating device 11 is an electric heating device, that is, the heating tube 111 is an electric heating tube, two ends of the heating tube 111 are respectively provided with a first electric connection end 1111 and a second electric connection end 1112, and the first electric connection end 1111 and the second electric connection end 1112 of the heating tube 111 are connected to an external circuit and then generate heat energy through an electric heating manner. Both ends of the steam pipe 112 are respectively provided with a water inlet 1121 and a steam outlet 1122, and water enters the steam pipe 112 from the water inlet 1121, is heated to form steam, and then is discharged out of the steam heater 5 through the steam outlet 1122. In operation, when the temperature sensor 14 detects that the temperature of the heater base 113 reaches a set value, the controller controls the water to be supplied into the steam pipe 112 to generate steam; meanwhile, the temperature and the dryness and humidity of the steam can be controlled by adjusting the set value.

Further, as shown in fig. 4, in the present embodiment, the temperature sensor 14 is disposed close to the heat generation pipe 111 and the steam pipe 112, and the temperature sensor 14 is not in contact with the heat generation pipe 111 and the steam pipe 112, so as not to cause the heat generation pipe 111 and the steam pipe 112 to affect the temperature detection value of the temperature sensor 14.

Further, as shown in fig. 4, in the present embodiment, the heater base 113 is provided with a mounting hole 115, and the temperature sensor 14 is disposed in the mounting hole 115. In this embodiment, the inner wall of the mounting hole 115 is threaded to facilitate the installation of the temperature sensor 14, i.e., the temperature sensor 14 is screwed into the mounting hole 115.

Further, in the present embodiment, the temperature sensor 14 includes the first temperature sensor 141 and the second temperature sensor 142, and both the first temperature sensor 141 and the second temperature sensor 142 are provided on the heater base 113. Specifically, the first temperature sensor 141 and the second temperature sensor 142 are used to detect the normal operating temperature and the off-protection temperature of the heating apparatus 11, respectively. In operation, when the first temperature sensor 141 detects that the temperature of the heater base 113 reaches a set value, the controller controls the inflow of water into the steam pipe 112 to generate steam; meanwhile, the temperature and the dryness and humidity of the steam can be controlled by adjusting the set value. Under normal conditions, when the first temperature sensor 141 works normally (i.e. the first temperature sensor 141 is not damaged), the temperature of the heating device 11 is controlled to be close to the normal working temperature, and the heating device 11 will not be overheated, but when the first temperature sensor 141 fails and cannot detect the temperature, the heating device 11 will continue to heat and dry heat, and there is a safety hazard. Therefore, the second temperature sensor 142 is mainly used for over-temperature protection, when the temperature detected by the second temperature sensor 142 reaches the shutdown protection temperature, the controller controls the steam heater 5 to stop working, and meanwhile, a text or sound warning can be set to remind a user that the temperature detection fails and the maintenance is needed in time. The set value of the turn-off protection temperature is higher than the set value of the normal working temperature. Further, as shown in fig. 4, in the present embodiment, the mounting holes 115 include first and second mounting holes 1151 and 1152 that are spaced apart from each other, and the first and second temperature sensors 141 and 142 are respectively disposed in the first and second mounting holes 1151 and 1152.

Further, in the present embodiment, the heater base 113 is formed by casting, and the heater base 113 is a cast aluminum piece or a cast copper piece. Specifically, during manufacturing, the manufactured heating tube 111 and steam tube 112 may be placed in a mold (not shown), and then molten aluminum or copper may be cast into the mold, and the heater base 113 may be obtained after the aluminum or copper is cooled. Since the heater base 113 is formed by casting, the heater base 113 can be in close contact with the heat generation pipe 111 and the steam pipe 112, i.e., the heat generation pipe 111 and the steam pipe 112 are closely covered by the heater base 113; meanwhile, since the heater base 113 is made of a material having excellent heat conductivity, such as copper or aluminum, the heat generated by the heating tube 111 can be rapidly conducted to the heater base 113, and the heater base 113 conducts the heat to the steam tube 112, so that the steam tube 112 is uniformly heated and rapidly heated, and the heat loss during the heat conduction process can be reduced. Of course, in other embodiments, the heater base 113 may be formed by other methods.

As shown in fig. 4, in the present embodiment, the heater base 113 has a first through hole 1132 and a second through hole 1133, and the water inlet 1121 and the steam outlet 1122 of the steam pipe 112 respectively pass through the first through hole 1132 and the second through hole 1133 and then are exposed outside the heater base 113, so as to facilitate connection between the steam pipe 112 and external pipelines. The heater base 113 is provided with a first through hole 1134 and a second through hole 1135, and the first electrical connection end 1111 and the second electrical connection end 1112 of the heating tube 111 respectively pass through the first through hole 1134 and the second through hole 1135 and then are exposed outside the heater base 113, so that the connection between the heating tube 111 and an external circuit is facilitated.

As can be seen from the above description of the specific embodiments, the control method for generating continuous steam provided by the present application feeds water in a manner of pulse type continuous water flow with alternating intensity, and the pulse type continuous water flow is heated and evaporated in the process of continuously flowing in the steam heater 5, so that the speed of generating steam is fast; moreover, because the water inlet into the steam heater 5 is pulse continuous water flow, the steam heater 5 can be rapidly heated and restored to the balance temperature capable of generating steam with preset quality in the process of alternating water flow strength, so that when each pulse water flow enters the steam heater 5, the self states of the steam heater 5 are the same or almost the same, the temperature drop caused by the heat absorption of the evaporation of the front water flow can be avoided, the generated steam can be dry steam with low humidity, and the steam is continuous and stable and controllable in quality.

Although the present invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present invention.

Claims (10)

1. A control method for generating continuous steam, which is applied to a steam generating system, wherein the steam generating system comprises a liquid inlet, a steam outlet, and a liquid pump, a water inlet valve and a steam heater which are connected between the liquid inlet and the steam outlet, and the water inlet valve and the liquid pump are sequentially connected between the liquid inlet and the steam heater, and the control method comprises the following steps:

s1, controlling the liquid pump to work to drive liquid to sequentially pass through the water inlet valve and the liquid pump from the liquid inlet and be conveyed to the steam heater in a heating state;

s2, controlling the water inlet valve to alternately work on and off at a preset frequency in the working period of the liquid pump, so that the liquid intermittently passes through the water inlet valve, and the liquid passing through the water inlet valve is conveyed to the steam heater through a pulse type continuous water flow with alternately changed strength after passing through the liquid pump;

wherein the pulsed continuous stream of water continuously flows within the steam heater and is at least partially vaporized prior to exiting the steam heater.

2. The method according to claim 1, wherein the portion of the conduit between the inlet valve and the liquid pump at least near the liquid pump is a filling section filled with liquid.

3. The control method for generating continuous steam according to claim 1, further comprising: s3, controlling the steam heater to heat, and detecting the actual temperature of the steam heater; and when the actual temperature of the steam heater reaches the preset temperature, executing the steps S1 and S2.

4. The control method for generating continuous steam according to claim 1, wherein the steam outlet has an open state and a closed state, and in the closed state of the steam outlet, the control method comprises: and controlling the steam heater to be in a heating state, and controlling the liquid pump to intermittently work so as to intermittently feed water into the steam heater.

5. The method as claimed in claim 4, wherein the frequency of the intermittent operation of the liquid pump is less than a predetermined frequency of the on/off alternation of the water inlet valve.

6. The method of claim 4, wherein said controlling said steam heater to be in a heating state and said liquid pump and said water inlet valve to intermittently operate to intermittently supply water to said steam heater comprises:

controlling the steam heater to work and detecting the working state of the steam heater, controlling the liquid pump and the water inlet valve to work to feed water into the steam heater when the working state of the steam heater reaches a preset condition, and controlling the liquid pump and the water inlet valve to stop feeding water into the steam heater when the working state of the steam heater does not reach the preset condition.

7. The control method of generating continuous steam according to claim 6, wherein the operating state of the steam heater reaching the preset condition includes that an actual temperature of the steam heater reaches a preset temperature.

8. The control method for continuous steam generation as claimed in claim 6, wherein the control method comprises: when the steam pressure in the steam generation system reaches a preset value, the steam is discharged through the pressure release valve to release the pressure.

9. The method of claim 1, wherein the liquid pump is a solenoid pump and the water inlet valve is a solenoid valve.

10. The control method for generating continuous steam according to any one of claims 1 to 9, wherein the control method is used for generating the steam in at least one preset dry humidity state, and the steam in the preset dry humidity state is realized by controlling the preset frequency of on-off alternate work of the water inlet valve.

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