Steam generator and steam generator water quality control method

Abstract

The invention provides a steam generator and a steam generator water quality control method. The steam generator comprises a generator shell, a heat exchange device, a water supplementing opening, a steam outlet and a sewage draining opening. The heat exchange device is arranged in the generator shell, the water supplementing opening is formed in the bottom of the generator shell, and the steam outlet is formed in the top of the generator shell. The sewage draining exit has an opening state and a closing state, and comprises a bottom sewage draining exit and a middle sewage draining exit; the bottom drain outlet is formed in the bottom of the generator shell and is staggered with the water replenishing port; the middle drain outlet is formed in the side wall of the generator shell; the invention further provides a water quality control method of the steam generator. The water quality control method is applied to the steam generator. The water quality control method of the steam generator is matched with the steam generator, the purpose of controlling the water quality of the steam generator is achieved with low cost, and the problems that steam generation is affected and equipment is corroded and damaged due to poor water quality in the prior art are solved.

Description

Technical Field

[0001] The invention relates to the field of heat exchange equipment, and in particular to a steam generator and a method for controlling water quality of the steam generator. Background Art

[0002] Steam generators are important equipment in the field of heat exchange. Steam generators transfer the heat energy of fuel or other energy sources to liquids through heating devices, heating the liquids into steam. They are widely used in production scenarios such as food processing, pharmaceutical textiles, vehicle manufacturing, and home appliance manufacturing, as well as in life scenarios such as equipment disinfection and sterilization, air conditioning, cooling and heating. Steam generators play a core role in energy conversion and industrial production, and also play an important role in medical care, environmental protection, and daily life.

[0003] When the steam generator is running, liquid medium is injected into the steam generator shell to maintain the liquid medium at a certain liquid level. The liquid medium is then heated by a heat exchange device laid in the steam generator shell to make the liquid boil and change into high-temperature steam. Finally, the steam is discharged to subsequent steam extraction equipment through a preset pipeline.

[0004] However, the liquid injected into the steam generator shell contains various substances dissolved in it, such as salts, acids, alkalis, etc. In addition, the liquid may also include suspended substances such as organic matter and insoluble salts, which affect the water quality. If the water quality is poor, there will be more insoluble dirt when the steam generator is running, and the substances dissolved in the water will also increase in concentration or precipitate to produce dirt due to evaporation and concentration, which will affect the steam generation efficiency and reduce the steam quality at the least, and corrode and damage the equipment at the worst, causing it to be scrapped. Summary of the invention

[0005] The present invention provides a steam generator and a steam generator water quality control method, which can achieve the purpose of controlling the water quality of the steam generator at a relatively low cost, so as to solve the problem in the related art that during the operation of the steam generator, the steam generation is affected and the equipment is corroded and damaged due to poor water quality.

[0006] In order to solve the problems in the prior art, the present invention is achieved as follows:

[0007] In a first aspect, an embodiment of the present invention provides a steam generator, the steam generator comprising:

[0008] Generator shell, heat exchange device, water supply port, steam outlet, and sewage outlet;

[0009] The heat exchange device is arranged inside the generator shell, the water replenishment port is arranged at the bottom of the generator shell, and the steam outlet is arranged at the top of the generator shell;

[0010] The sewage outlet has two states of open and closed, and the sewage outlet includes a bottom sewage outlet and a middle sewage outlet; the bottom sewage outlet is arranged at the bottom of the generator shell and is staggered with the water replenishment port; the middle sewage outlet is arranged on the side wall of the generator shell.

[0011] Optionally, a gas-liquid separation device is provided at the connecting position between the generator shell and the central sewage outlet, and the gas-liquid separation device is composed of a first baffle and a second baffle which are vertically connected to each other, and the side of the first baffle away from the second baffle is connected to the bottom of the central sewage outlet, and the second baffle faces the central sewage outlet; the lengths of the first baffle and the second baffle are both greater than the diameter of the central sewage outlet.

[0012] Optionally, a liquid level gauge is provided on the outside of the generator shell, one end of the liquid level gauge is connected to the bottom of the generator shell and is located near the water replenishment port, and the other end of the liquid level gauge is connected to the top of the generator shell; the liquid level gauge is used to detect the liquid level height of the liquid inside the generator shell, and the measuring range of the liquid level gauge covers the control range of the liquid level height of the liquid inside the generator shell.

[0013] Optionally, the central sewage outlet is provided with a valve with adjustable opening and a water quality sensor; the water quality sensor is used to detect water quality parameters of the liquid entering the central sewage outlet.

[0014] Optionally, the heat exchange device includes a plurality of heat exchange tubes, which are laid in parallel and evenly spaced on the inner bottom layer of the generator shell to form a heat exchange tube bundle, and the height of the heat exchange tube bundle is lower than the middle sewage outlet.

[0015] In a second aspect, an embodiment of the present invention provides a method for controlling water quality of a steam generator, which is applied to a steam generator as described in any one of the above items, and the method comprises:

[0016] Open the water replenishment port to replenish liquid into the generator shell, and obtain the liquid level height of the liquid inside the generator shell and the water quality parameters of the liquid entering the middle sewage outlet;

[0017] Controlling the valve opening of the water replenishment port according to the liquid level, and controlling the valve opening of the middle sewage outlet according to the water quality parameter, so that the difference between the liquid level of the liquid inside the generator housing and the height of the middle sewage outlet is less than or equal to a preset threshold;

[0018] The bottom drain outlet is opened at a preset period, and after it is detected that the bottom drain outlet discharges a first set amount of liquid, the bottom drain outlet is closed.

[0019] Optionally, the step of controlling the valve opening of the water replenishment port according to the liquid level comprises:

[0020] When the liquid level meter detects that the liquid level is higher than the middle sewage outlet, the valve opening of the water supply outlet is controlled to decrease;

[0021] When the liquid level meter detects that the liquid level is lower than the middle sewage outlet, the valve opening of the water replenishment outlet is controlled to increase.

[0022] Optionally, the step of controlling the valve opening of the middle sewage outlet according to the water quality parameter includes:

[0023] When the water quality sensor detects that the water quality parameter rises and exceeds a preset water quality threshold, the valve opening of the middle sewage outlet is controlled to increase;

[0024] When the water quality sensor detects that the water quality parameter is equal to the preset water quality threshold, the valve opening of the middle sewage outlet is controlled to decrease.

[0025] Optionally, after the step of controlling the valve opening of the water replenishment port according to the liquid level and controlling the valve opening of the middle sewage outlet according to the water quality parameter, the method further includes:

[0026] When the water quality sensor detects that the water quality parameter is less than the set value of the water quality parameter, the middle sewage outlet is controlled to be closed.

[0027] Optionally, after the step of controlling the valve opening of the water replenishment port according to the liquid level and controlling the valve opening of the middle sewage outlet according to the water quality parameter, the method further includes:

[0028] When the liquid level meter detects that the middle sewage outlet discharges a second set amount of liquid, the middle sewage outlet is controlled to be closed.

[0029] Optionally, after the step of controlling the valve opening of the water replenishment port according to the liquid level and controlling the valve opening of the middle sewage outlet according to the water quality parameter, the method further includes:

[0030] When the water quality sensor detects that the water quality parameter changes by more than a preset threshold value within a set time, the valve of the water replenishment port is restored to an initial opening.

[0031] Optionally, the step of opening the bottom drain outlet at a preset period and closing the bottom drain outlet after detecting that the bottom drain outlet discharges a first set amount of liquid comprises:

[0032] While the bottom sewage outlet is opened, the middle sewage outlet is controlled to be closed.

[0033] In the embodiment of the present invention, on the basis of realizing the basic functions of the steam generator, a bottom drain port and a middle drain port are opened on the steam generator shell, and the dirt settled to the bottom of the steam generator shell is discharged through the bottom drain port, and the dirt floating on the liquid surface is discharged through the middle drain port; by controlling the water replenishment port to replenish liquid, the bottom drain port and the middle drain port are controlled to discharge dirt and part of the liquid, so as to realize the water quality control of the steam generator, and avoid the adverse effects of poor water quality on the operation of the steam generator, especially the reduction of steam generation quality and efficiency and the corrosion damage to the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0035] Figure 1 An operation schematic diagram of a steam generator provided by an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of a control model of a steam generator provided in an embodiment of the present invention;

[0037] Figure 3 A schematic structural diagram of a gas-liquid separation device for a steam generator provided in an embodiment of the present invention;

[0038] Figure 4 A schematic diagram of another control model of a steam generator provided in an embodiment of the present invention;

[0039] Figure 5 A flow chart of the steps of a steam generator water quality control method provided by an embodiment of the present invention.

[0040] Among them: 10-generator shell, 20-heat exchange device, 30-water supply port, 40-steam outlet, 50 sewage outlet, 60-liquid level meter, 70-gas-liquid separation device, 21-heat exchange tube, 31-water supply port valve, 51-bottom sewage outlet, 511-bottom sewage outlet valve, 52-middle sewage outlet, 521-middle sewage outlet valve, 522-water quality sensor, 71-first baffle, 72-second baffle. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can also be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0042] like Figure 1 As shown, it is an operation schematic diagram of a steam generator provided by an embodiment of the present invention, and the structure of the steam generator includes: a generator shell 10, a heat exchange device 20, a water supply port 30, a steam outlet 40, and a sewage outlet 50; the heat exchange device 20 is arranged inside the generator shell 10, the water supply port 30 is arranged at the bottom of the generator shell 10, and the steam outlet 40 is arranged at the top of the generator shell 10; the sewage outlet 50 has two states of opening and closing, and the sewage outlet 50 includes a bottom sewage outlet 51 and a middle sewage outlet 52; the bottom sewage outlet 51 is arranged at the bottom of the generator shell 10, and is staggered with the water supply port 30; the middle sewage outlet 52 is arranged on the side wall of the generator shell 10.

[0043] Steam generator is a commonly used heat exchange equipment, among which flooded evaporator is a common form of steam generator. It has the advantages of high heat transfer efficiency, compact structure, easy cleaning and maintenance, energy saving and high efficiency, and is suitable for use in various units. Its basic working principle is as follows: the liquid required to generate steam is sent into the steam generator through the water supply port after the throttling device, and the liquid is kept at a certain liquid level inside the steam generator, so that the heat exchange device is immersed in the liquid, and the high-temperature heat exchange medium flows in the heat exchange device and transfers heat to the outer surface of the heat exchange device. The heat transferred by the heat exchange device will gradually vaporize and evaporate the liquid to boiling, during which it will phase change into steam, and then be transported from the steam outlet to the subsequent required equipment.

[0044] As a device that directly generates steam, the durability of the steam generator is related to the water quality of the replenished liquid. For example, if there are more chloride ions in the replenished liquid, the high concentration of chloride ions after evaporation and concentration will cause corrosion to the metal parts in the equipment. When there are more carbonates and hydroxide ions in the replenished liquid, carbon dioxide will be generated during the operation of the equipment, which will increase the acidity of the water, leading to hydrogen precipitation and corroding and damaging metal parts. When the alkalinity of the replenished liquid is high, it will dissolve the passivation film on the surface of the metal parts, causing the metal to be continuously corroded, and will also cause alkaline embrittlement of the metal parts, resulting in local structural fractures, causing the pressure vessel to fail and further cause accidents, and will also increase the foam on the surface of the liquid in the steam generator, increasing the risk of steam-water co-boiling. Steam-water co-boiling refers to the phenomenon that during the operation of the steam generator, the water level fluctuates sharply or a large amount of foam is generated due to the violent disturbance and mixing of liquid and steam. Water-vapor co-boiling usually occurs on the evaporation surface or in the liquid level gauge in the steam generator. When the liquid in the steam generator is heated to near the saturation temperature, the gas dissolved in the liquid begins to release, forming a large amount of foam and fluctuating up and down. The main characteristics of steam-water co-boiling include the appearance of a large amount of foam in the water level gauge, violent fluctuations in the water level, and a sharp drop in the temperature of the superheated steam. In severe cases, water hammer will occur in the steam pipe. The consequences of steam-water co-boiling are serious, which will lead to a sharp deterioration in steam quality, scaling and water hammer vibration of the heating device, damage to the heating device or affect the safe operation of subsequent gas-using equipment. When the hardness of the replenished liquid is too high, dirt will be deposited on the surface of the heat exchange device, increasing thermal resistance and reducing boiling heat transfer efficiency. In general, poor water quality will affect the quality and efficiency of steam generation, corrode or even damage equipment. Therefore, when the liquid water quality is found to be poor, measures must be taken to deal with it, such as reducing the heat exchange intensity, reducing the subsequent load, closing the main steam valve, strengthening the drainage of the steam pipeline, opening the drain valve to continuously drain water or regularly opening the drain valve to drain water, so as to improve the water quality of the liquid for steam generation. Among them, the use of the drain valve is the main means to improve the water quality of the steam generator.

[0045] Regarding improving the water quality of the steam generator through a drain valve, in the relevant technical scheme, a drain port is opened at the bottom of the steam generator, and a sedimentation agent is used, which is a more common technical scheme for controlling water quality. The sedimentation agent is sent into the steam generator through the water replenishment port, so that it reacts with the substances dissolved or suspended in the liquid of the steam generator to generate precipitates. Some solid dirt will be deposited to the bottom of the steam generator, and finally these precipitates will be discharged from the steam generator through the drain port opened at the bottom. However, this scheme can only discharge the dirt deposited and accumulated at the bottom of the steam generator. There is no better way to deal with the dirt floating near the liquid surface of the replenished liquid during the steam generation process, and the evaporation process will increase the concentration of the sedimentation agent, which in disguise increases the concentration of suspended matter or ions in the liquid. In general, the water quality control ability of the relevant technical scheme is not good.

[0046] To this end, the embodiment of the present invention first provides a steam generator, which has a bottom drain port 51 and a middle drain port 52 on the side wall of the generator shell 10 to enhance the water quality control capability of the steam generator. Specifically, in the embodiment of the present invention, a full-liquid evaporator is used, and staggered water replenishment ports 30 and bottom drain ports 51 are provided at the bottom of the generator shell 10, and a middle drain port 52 is provided on the side wall of the generator shell. Both the bottom drain port 51 and the middle drain port 52 can be opened or closed, and the steam outlet 40 is arranged at the top of the shell; the replenished liquid is sent into the generator shell 10 through the water replenishment port 20 as shown in the X direction, and the heat exchange device 20 is immersed, so that the liquid and the heat exchange device 20 are fully in contact, and the medium inside the heat exchange device 20 is continuously heated, and the replenished liquid is converted into steam, and the steam flows to the steam outlet 40 at the top of the generator shell 10 in the Y direction, and is finally sent to the subsequent equipment. During the steam generation process, if dirt is deposited and accumulated at the bottom of the steam generator, the bottom drain port 51 is opened to allow part of the liquid to be discharged together with the dirt as shown in the Z direction; if dirt is floating on the liquid surface in the steam generator, the liquid surface is maintained to be flush with the middle drain port 52, and the middle drain port 52 is opened at the same time to allow part of the liquid to be discharged together with the dirt as shown in the W direction; through the above-mentioned arrangement, the dirt floating on the liquid surface and deposited on the bottom surface of the generator shell are effectively treated and no longer corrode and damage the equipment, while the substances dissolved in the liquid are continuously precipitated and discharged, thereby reducing the liquid concentration ratio, enhancing the evaporation capacity of the liquid, and reducing the concentration of dissolved substances; by treating the dirt and reducing the concentration of dissolved substances, the water quality of the steam generator is controlled.

[0047] The steam generator provided in the embodiment of the present invention, on the basis of realizing the basic functions of the steam generator, is provided with a bottom drain outlet and a middle drain outlet on the steam generator shell, and the dirt settled to the bottom of the steam generator shell is discharged through the bottom drain outlet, and the dirt floating on the liquid surface is discharged through the middle drain outlet; the water quality of the steam generator is controlled by replenishing liquid by controlling the water replenishment port and controlling the bottom drain outlet and the middle drain outlet to discharge dirt and part of the liquid, thereby avoiding the adverse effects of poor water quality on the operation of the steam generator, especially the reduction of steam generation quality and efficiency and corrosion damage to equipment.

[0048] Optional, such as Figure 2 As shown in FIG. 1 , a control model schematic diagram of a steam generator provided in an embodiment of the present invention is provided, wherein a gas-liquid separation device 70 is provided at the connection position between the generator housing 10 and the middle sewage outlet 52. Figure 3As shown, it is a structural schematic diagram of a gas-liquid separation device of a steam generator provided in an embodiment of the present invention. The gas-liquid separation device 70 is composed of a first baffle 71 and a second baffle 72 which are vertically connected to each other. The side of the first baffle 71 facing away from the second baffle 72 is connected to the bottom of the middle sewage outlet 52, and the second baffle 71 faces the middle sewage outlet 52; the lengths of the first baffle 71 and the second baffle 72 are both greater than the diameter of the middle sewage outlet 52.

[0049] Furthermore, a gas-liquid separation device 70 is provided at the middle sewage outlet 52, and the separation device 70 is composed of a first baffle 71 and a second baffle 72 which are perpendicular to each other; the first baffle 71 blocks the liquid from entering the middle sewage outlet 52 from the bottom, and the second baffle 72 blocks the liquid from entering the middle sewage outlet 52 from the side. Through the above arrangement, when the liquid level in the steam generator overflows the second baffle 72, the dirt floating on the liquid surface is discharged from the middle sewage outlet 52 along with the liquid; in addition, the main function of the gas-liquid separation device 70 is to prevent bubbles generated by boiling on the surface of the heat exchange device 20 from entering the middle sewage outlet 52, so as to avoid the interference of bubbles on the sewage discharge process or subsequent detection operations. The gas-liquid separation device 70 can be made of stainless steel and directly fixed at the set position of the generator housing 10 by welding; as for the length of the gas-liquid separation device 70, it is sufficient to ensure that the first baffle 71 and the second baffle 72 block the middle sewage outlet so that the floating bubbles cannot enter the middle sewage outlet 52. As for the connection between the two baffles and the generator housing 10 in the length direction, it can be extended until the baffle contacts and connects to the end face of the generator housing 10, or after the baffle length exceeds the diameter of the middle sewage outlet 52, additional baffles can be set to block the two ends of the length direction of the gas-liquid separation device 70. The embodiment of the present invention does not make specific restrictions on this.

[0050] Optional, such as Figure 2 As shown, a liquid level gauge 60 is provided on the outside of the generator shell 10, one end of the liquid level gauge 60 is connected to the bottom of the generator shell 10 and is located near the water replenishment port 20, and the other end of the liquid level gauge 60 is connected to the top of the generator shell 10; the liquid level gauge 60 is used to detect the liquid level height of the liquid inside the generator shell 10, and the measuring range of the liquid level gauge covers the control range of the liquid level height of the liquid inside the generator shell.

[0051] In the embodiment of the present invention, if the liquid level needs to be regulated, a liquid level meter is required to detect the liquid level. Accordingly, the range of the liquid level meter needs to cover the regulating range of the liquid level inside the generator housing. Figure 2 and Figure 4 As shown, Figure 4A schematic diagram of another control model of a steam generator provided in an embodiment of the present invention. In both control models, the change in the liquid level inside the steam generator shell 10 can be observed through the liquid level meter 60 on the outside of the generator shell 10, and the detection result will be sent to the control system to execute the corresponding control logic.

[0052] Optional, such as Figure 4 As shown, the middle sewage outlet 52 is provided with a valve with adjustable opening and a water quality sensor 522 ; the water quality sensor 522 is used to detect the water quality parameters of the liquid entering the middle sewage outlet 52 .

[0053] In such Figure 4 In the control model shown, a valve with adjustable opening, i.e., a valve 521 of the middle sewage outlet, is provided at the middle sewage outlet 52, and a water quality sensor 522 is provided. The valve 521 of the middle sewage outlet is a regulating valve, which is usually composed of a valve body, a valve core, an actuator, a valve seat and other components. The regulating valve automatically adjusts the opening of the valve by receiving a signal from a controller, thereby changing the flow rate and flow velocity of the liquid medium flowing through, i.e., the liquid entering the middle sewage outlet 52. In the embodiment of the present invention, the flow characteristic of the valve of the middle sewage outlet can be any one of linear, equal percentage, and parabola, and the embodiment of the present invention does not impose any further restrictions on this. The water quality sensor is a device for monitoring the quality of liquid. It evaluates the degree of liquid pollution or water quality by measuring various physical, chemical or biological parameters in the liquid. It is widely used in environmental monitoring, water treatment, agricultural irrigation and drinking water safety. The working principle of the water quality sensor is based on different technologies, including electrochemical principle, optical principle and physical principle. For example, the total dissolved solids (TDS) water quality sensor indirectly estimates the TDS content by measuring the conductivity in the water. When the dissolved ions in the water increase, the conductivity will also increase accordingly. In addition, the water quality sensor can also detect various parameters such as hydrogen ion concentration index, dissolved oxygen, turbidity, temperature, etc. In the embodiment of the present invention, the corresponding water quality sensor is used and deployed according to the water quality parameters to be detected. The liquid discharged through the middle sewage outlet 52 is sampled and measured by the water quality sensor 522. According to the measured water quality parameters, the opening of the middle sewage outlet valve 521 is infinitely adjusted to realize the flow rate control of the middle sewage outlet 52, thereby further realizing the precise control of the evaporator water quality.

[0054] Optional, such as Figure 1 As shown, the heat exchange device 20 includes a plurality of heat exchange tubes 21 , which are laid in parallel and evenly spaced on the inner bottom layer of the generator shell 10 to form a heat exchange tube bundle, and the height of the heat exchange tube bundle is lower than the middle sewage outlet 52 .

[0055] The heat exchange tubes 21 are evenly spaced and laid on the inner bottom layer of the generator shell 10. When the liquid in the generator shell 10 immerses the heat exchange device 20, the contact area with the heat exchange device 20 is maximized, the heat exchange efficiency is improved, and the steam generation efficiency is enhanced; the heat exchange tube bundle composed of the heat exchange tubes 21 is lower than the middle drain port 52, so that the liquid can immerse the heat exchange device 20 before being discharged through the middle drain port 52, thereby avoiding the liquid near the heat exchange device 20 being discharged from the middle drain port 52 before being fully heated, thereby reducing heat loss.

[0056] In the steam generator provided in the embodiment of the present invention, a sewage outlet is respectively arranged at the bottom and the side wall of the generator shell to realize double sewage discharge; a gas-liquid separation device is arranged at the middle sewage outlet of the side wall of the generator shell to prevent the influence of bubbles generated during evaporation on the sewage discharge process of the middle sewage outlet; a valve with adjustable opening and a water quality sensor are arranged at the middle sewage outlet to realize precise adjustment of the sewage discharge volume; a liquid level meter is arranged to detect the liquid level height of the liquid when the water quality needs to be regulated; the heat exchange device is a heat exchange light beam to maximize the heat exchange efficiency; through the integration of the above technical solutions, dirt can be discharged without stopping the machine, and the concentration of dissolved substances can be reduced, so as to achieve the purpose of controlling water quality while maintaining the efficient operation of the steam generator and realizing the steam generation effect.

[0057] In a second aspect, the present invention provides a steam generator water quality control method, which is applied to the steam generator mentioned above.

[0058] like Figure 5 FIG. 1 is a flow chart of steps of a steam generator water quality control method provided by an embodiment of the present invention, and the control method comprises:

[0059] Step 101, open the water replenishment port, replenish liquid into the generator shell, obtain the liquid level height of the liquid inside the generator shell and the water quality parameters of the liquid entering the middle sewage outlet.

[0060] In an embodiment of the present invention, the water quality control process begins during the steam generation operation, that is, while liquid is replenished into the generator shell through the water replenishment port, the middle drain port is opened, the liquid level inside the generator shell is obtained by a liquid level meter, and the water quality parameters of the liquid entering the middle drain port are detected by a water quality sensor, in preparation for subsequent precise control.

[0061] Step 102, controlling the valve opening of the water replenishment port according to the liquid level, and controlling the valve opening of the middle sewage outlet according to the water quality parameters, so that the difference between the liquid level inside the generator shell and the height of the middle sewage outlet is less than or equal to a preset threshold.

[0062] After obtaining the liquid level, the valve opening of the water replenishment port can be controlled by the liquid level. The valve of the water replenishment port here adopts an adjustable valve, and the opening can be infinitely adjusted to control the flow rate and flow velocity of the replenishment liquid entering the generator shell. In addition, in addition to the adjustable valve, the water replenishment port is also provided with a reflux valve to prevent the liquid in the generator shell from flowing back after the water replenishment port is opened. In order to avoid misunderstanding or unclear reference, in other parts of the embodiments of the present invention, unless otherwise specified, the valve of the water replenishment port refers to an adjustable valve. After obtaining the water quality parameters, the opening of the valve of the middle sewage outlet can be controlled by the water quality parameters. The valve of the middle sewage outlet here is the same as the middle sewage outlet valve mentioned above. , and the valve with adjustable opening arranged at the middle sewage outlet all refer to the same valve, which is a regulating valve and can adjust the opening infinitely so as to control the flow rate and flow velocity of the liquid discharged from the middle sewage outlet, and correspondingly, the discharge volume of the middle sewage outlet is also controlled; by adjusting the above two valves, the liquid level in the generator shell is maintained at the middle sewage outlet, specifically, the difference between the liquid level in the generator shell and the height of the middle sewage outlet is made less than or equal to a preset threshold value. In this case, the liquid near the liquid surface will continuously flow into the middle sewage outlet, and the floating dirt will be discharged from the generator shell, thereby achieving the purpose of continuously discharging dirt through the middle sewage outlet.

[0063] Step 103, opening the bottom drain outlet at a preset period, and closing the bottom drain outlet after detecting that the bottom drain outlet discharges a first set amount of liquid.

[0064] In addition to the control of the middle drain port, the bottom drain port is regularly controlled to open to target the dirt deposited at the bottom of the generator shell, so that the liquid at the bottom of the generator shell can be discharged from the generator shell along with the deposited dirt. In order to avoid the bottom drain port being open for a long time, which may lead to insufficient liquid for heat exchange in the generator shell, the bottom drain port will be closed after it is detected that the bottom drain port has discharged the first set amount of liquid to ensure the normal operation of the steam generation process. The first set amount here is determined by the amount of replenished liquid. When the middle drain port is not opened, it is generally 5%-10% of the amount of replenished liquid in the interval between two bottom drain operations.

[0065] Optionally, the step of controlling the valve opening of the water replenishment port according to the liquid level in step 102 includes:

[0066] Sub-step 1021, when the liquid level meter detects that the liquid level is higher than the middle sewage outlet, controlling the valve opening of the water replenishment outlet to decrease;

[0067] Sub-step 1022: When the liquid level meter detects that the liquid level is lower than the middle sewage outlet, the valve opening of the water replenishment outlet is controlled to increase.

[0068] With regard to controlling the valve opening of the water replenishment port according to the liquid level, specifically, when the liquid level in the generator shell rises to a level higher than the height of the middle drain port, the valve opening of the water replenishment port is controlled to be reduced, thereby reducing the flow rate and flow rate of the replenishment liquid entering the generator shell. The height of the middle drain port here refers to the height of the upper edge of the middle drain port, that is, at this time, the liquid in the generator shell completely submerges the middle drain port. Obviously, if the opening of the valve of the middle drain port remains unchanged at this time, the liquid level in the generator shell will continue to decrease; when the liquid level in the generator shell drops to a level lower than the middle drain port, When the height of the sewage outlet is increased, the valve opening of the water supply port is controlled to increase, and the flow rate and flow of the supplementary liquid entering the generator shell are increased. The height of the middle sewage outlet here refers to the height of the lower edge of the middle sewage outlet. After the gas-liquid separation device is set, it refers to the height between the end face of the second baffle away from the first baffle and the bottom surface of the generator shell. That is, at this time, if the bottom sewage outlet is not opened, the liquid in the generator shell can only be converted into steam through heat exchange to leave the generator shell. Obviously, if the opening of the middle sewage outlet valve does not change at this time, the liquid level of the liquid in the generator shell will continue to rise.

[0069] It should be noted that there is no clear time sequence between sub-step 1021 and sub-step 1022. The order in which these two steps are executed depends on the situation in which the water quality control step process is executed, that is, during the steam generation process, if the water quality control process is executed when the liquid level is higher than the height of the middle sewage outlet, the middle sewage outlet is opened, and sub-step 1021 is executed first. On the contrary, if the water quality control process is executed when the liquid level is lower than the height of the middle sewage outlet, the middle sewage outlet is opened, and sub-step 1022 is executed first. The above setting scheme adjusts the valve opening of the water replenishment port according to the liquid level detected by the liquid level meter, controls the amount of liquid added into the generator housing, and makes the liquid level adjustable.

[0070] Optionally, the step of controlling the valve opening of the middle sewage outlet according to the water quality parameter in step 102 includes:

[0071] Sub-step 1023: when the water quality sensor detects that the water quality parameter rises and exceeds a preset water quality threshold, controlling the valve opening of the middle sewage outlet to increase;

[0072] Sub-step 1024: When the water quality sensor detects that the water quality parameter is equal to the preset water quality threshold, control the valve opening of the middle sewage outlet to decrease.

[0073] In step 102, in addition to controlling the valve opening of the water replenishment port according to the liquid level, the valve opening of the middle sewage outlet is also controlled by water quality parameters; specifically, after the liquid passes through the middle sewage outlet, it will be sampled and detected by the water quality sensor to obtain water quality parameters. In the embodiment of the present invention, the conductivity of the liquid is generally selected as a representative water quality parameter. The conductivity is an important indicator for measuring the ionic strength in the liquid. It reflects the total concentration of ions in the solution. The conductivity is proportional to the total concentration of charged substances such as salts, acids, and alkalis dissolved in the liquid. When the liquid contains inorganic acids, alkalis, salts or organic charged colloids, the conductivity will increase. Therefore, the conductivity is often used to indirectly infer the total concentration of charged substances in the liquid. This indicator can be used as a representative water quality parameter to evaluate the water quality. In addition, the hydrogen ion concentration index (Pondus Hydrogenii, pH), alkalinity, and solid solubility of the liquid can also be selected as representative water quality parameters participating in the control process.

[0074] Taking conductivity as an example, if the water quality sensor detects that the water quality parameter rises and exceeds the preset water quality threshold, it is considered that the concentration of dissolved substances in the liquid in the generator shell increases, and the corresponding water quality is deteriorating. At this time, the valve opening of the central sewage outlet is controlled to increase, and the flow rate and flow of the liquid discharged from the generator shell through the central sewage outlet are increased, and the rate at which dirt is discharged through the central sewage outlet is increased. Obviously, when the valve opening of the water replenishment port remains unchanged, the liquid level of the liquid in the generator shell will continue to decrease; if the water quality sensor detects that the water quality parameter is equal to the preset water quality threshold, it is considered that the concentration of dissolved substances in the liquid in the generator shell is maintained at an appropriate level. At this level, it is necessary to give priority to ensuring the operation of the steam generation process, and the discharge volume can be reduced, that is, the valve opening of the central sewage outlet is controlled to decrease, and the flow rate and flow of the liquid discharged from the generator shell through the central sewage outlet are reduced, and the rate at which dirt is discharged through the central sewage outlet is reduced. Obviously, when the valve opening of the water replenishment port remains unchanged, the page height of the liquid in the generator shell will continue to rise. It should be noted that, similar to sub-steps 1021 and 1022, there is no clear sequential relationship between the execution of sub-steps 1023 and 1024. The execution order of sub-steps 1023 and 1024 depends on the relationship between the water quality parameters and the preset water quality threshold when the water quality sensor described in this paragraph detects the water quality parameters; in addition, the above-mentioned water quality threshold is the set threshold of the water quality parameter. If conductivity is taken as an example, the water quality threshold is the threshold of conductivity, which can be set with reference to the national standard for industrial boiler water quality. The above-mentioned setting scheme adjusts the valve opening of the middle sewage outlet according to the water quality parameters detected by the water quality sensor, controls the amount of liquid discharged from the generator shell, and makes the liquid level adjustable.

[0075] Through the cooperation of sub-steps 1021, 1022, 1023, and 1024, the liquid level inside the generator housing is adjusted to a difference with the height of the middle drain outlet that is less than or equal to a preset threshold. It should be noted that the height of the middle drain outlet here refers to the height of the center of the diameter of the middle drain outlet. If a gas-liquid separation device is provided outside the middle drain outlet, it refers to the height between the end surface of the second baffle away from the first baffle and the bottom surface of the generator housing. Through the above-mentioned arrangement, the liquid level inside the generator shell is maintained at a position where sewage can be continuously discharged, that is, in this state, the liquid in the generator shell will continuously flow into the middle sewage outlet, which will discharge dirt floating on the liquid surface on the one hand, and substances dissolved in the liquid on the other hand. At the same time, the concentration of various dissolved substances in the liquid replenished into the generator shell through the water replenishment port remains basically unchanged. After mixing with the original liquid in the generator shell, the concentration of dissolved substances in the liquid in the generator shell will decrease; by discharging the concentration of floating dirt and dissolved substances, the water quality of the steam generator is controlled; further, the execution of step 102 is completed by the two precise values ​​of the liquid level height and the water quality parameter in conjunction with the steplessly adjustable valve, so that timely and accurate adjustment feedback can be achieved, making the control process of the water quality of the steam generator more accurate.

[0076] Optionally, after step 102, the method further includes:

[0077] Step A1: When the water quality sensor detects that the water quality parameter is less than the preset water quality threshold, the middle sewage outlet is controlled to be closed.

[0078] The middle sewage outlet does not need to be open all the time. During the process of discharging liquids and sewage at the middle sewage outlet, if the water quality sensor detects that the water quality parameters are less than the preset water quality threshold, it is considered that the water quality of the steam generator is good at this time, and there is no need to perform drainage operations. At this time, the middle sewage outlet will be controlled to be closed to prevent heat from being transferred out of the steam generator with the drainage operations, causing heat loss and affecting the efficiency of steam generation.

[0079] Optionally, after step 102, the method further includes:

[0080] Step B1: When the liquid level meter detects that the middle sewage outlet discharges a second set amount of liquid, control the middle sewage outlet to close.

[0081] In the control scheme when the water quality sensor fails or is not installed, the middle sewage outlet can also be controlled by the change in the liquid in the generator housing detected by the liquid level meter, so that it can be closed when necessary; specifically, when the liquid level meter detects that the middle sewage outlet discharges a second set amount of liquid, the middle sewage outlet is controlled to be closed. The second set amount here is determined by the amount of replenished liquid. When the bottom sewage outlet is not opened, it is generally 5%-10% of the amount of liquid replenished in the interval between two middle sewage discharge operations.

[0082] Optionally, after step 102, the method further includes:

[0083] Step C1: when the water quality sensor detects that the water quality parameter changes by more than a preset threshold value within a set time, restore the valve of the water replenishment port to an initial opening.

[0084] When the sewage is discharged at the middle sewage outlet, if the liquid level in the generator shell drops below the upper edge of the middle sewage outlet, in addition to the liquid, some air will enter the middle sewage outlet. For the water quality sensor at the middle sewage outlet, the water quality parameters detected at the sampling position will suddenly change due to the entry of air, that is, a change greater than a preset threshold will occur within the set time. In the embodiment of the present invention, it is considered that the steam generator has started to discharge liquid and sewage through the middle sewage outlet. At this time, the valve of the water replenishment port will be adjusted to restore the valve of the water replenishment port to its initial opening. Correspondingly, if the generator The liquid level in the generator shell rises to the level of the lower edge of the middle drain port, or when a gas-liquid separation device is provided, it rises to the level of the end face of the second baffle away from the first baffle, so that the liquid has just entered the opened middle drain port. The water quality parameters detected at the sampling position of the water quality sensor will also change suddenly, and a change greater than the preset threshold value will occur within the set time. Similarly, in the embodiment of the present invention, it is also considered that the steam generator has begun to discharge liquid and sewage through the middle drain port at this time. At this time, the valve of the water replenishment port will be adjusted to restore the valve of the water replenishment port to the initial opening. The above-mentioned initial opening refers to the opening at which the valve of the water replenishment port is located when the middle drain port is opened. Through the above-mentioned arrangement, the capacity of the liquid in the generator shell can be maintained at the amount required for the discharge process of the middle drain port for a long time.

[0085] Regarding the timing relationship among step A1, step B1 and step C1, step A1 and step B1 are mutually replaceable, that is, after step 102, one of step A1 and step B1 is executed, and step A1 and step B1 cannot be executed at the same time. There is no restriction on the timing position of step C1 among the three, that is, after step 102, step C1 can be executed simultaneously with any one of step A1 or step B1, and can also be executed before or after any one of step A1 or step B1. The embodiment of the present invention is not limited to this.

[0086] Optionally, the step of opening the bottom drain outlet at every preset period in step 103, and closing the bottom drain outlet after detecting that the bottom drain outlet discharges a first set amount of liquid, comprises:

[0087] While the bottom sewage outlet is opened, the middle sewage outlet is controlled to be closed.

[0088] When controlling the bottom sewage outlet, the bottom sewage outlet and the middle sewage outlet can be opened at the same time, but in this case, the two sewage outlets discharge sewage and liquid at the same time, and the liquid level meter cannot accurately determine the displacement of each of the two sewage outlets, and it is also impossible to control the valve of the middle sewage outlet according to the displacement feedback of the middle sewage outlet. Therefore, the two sewage outlets are opened at the same time only when there is no need for the middle sewage outlet valve to participate in the adjustment. It should be noted that the total displacement can still be measured by the liquid level meter at this time; in situations where precise control of water quality is required, when the bottom sewage outlet is opened, the middle sewage outlet will be controlled to be closed, and accordingly, when the middle sewage outlet is opened, the bottom sewage outlet will be controlled to be closed; it can be understood that in situations where precise control of water quality is required, the middle sewage outlet and the bottom sewage outlet are opened alternately. In an embodiment not shown in the present invention, in addition to periodically closing the bottom sewage outlet by detecting the first set amount through a liquid level meter in cooperation with the control system, a preset time length can also be set for the bottom sewage outlet. After the control system detects that the open state of the bottom sewage outlet remains for a preset time length, the control system closes the bottom sewage outlet.

[0089] For ease of understanding, the present invention provides two control models: Figure 2 and Figure 4 The control model shown.

[0090] exist Figure 2 In the control model shown, for the steam generation process, the liquid to be evaporated enters the generator housing 10 through the water replenishment port 30 in the X direction, is converted into steam under the action of the heat exchange device 20, and rises in the Y direction to the steam outlet 40 to enter the subsequent equipment.

[0091] For water quality control process, Figure 2 The middle sewage outlet of the steam generator is not equipped with a water quality sensor. In this model, the middle sewage outlet 52 and the bottom sewage outlet 51 will be opened alternately and regularly. The control system only controls the opening and closing state of the middle sewage outlet valve 521, but does not control its opening degree. The opening degree of the water replenishment port valve 31 is only controlled according to the needs of the steam generation process. During the water quality control process, the control system only monitors the liquid replenishment amount of the water replenishment port 30. The role of the gas-liquid separation device 70 in this model is to prevent the bubbles generated by boiling from entering the middle sewage outlet 52, thereby affecting the sewage discharge efficiency of the middle sewage outlet 52.

[0092] like Figure 2 As shown, the control system controls the middle sewage outlet valve 521 to open, so that after the middle sewage outlet 52 is opened, the liquid level of the liquid in the generator shell 10 continues to decrease. During this period, the control system will record the change of the liquid level through the liquid level meter 60, and calculate the sewage discharge volume of the middle sewage outlet 52 according to the change value of the liquid level. When the sewage discharge volume of the middle sewage outlet 52 exceeds the second set value, the middle sewage outlet 52 is closed; based on the same control logic, the control system opens the bottom sewage outlet valve 511, so that after the bottom sewage outlet 51 is opened, the liquid level of the liquid in the generator shell 10 continues to decrease. During this period, the control system will record the change of the liquid level through the liquid level meter 60, and calculate the sewage discharge volume of the bottom sewage outlet 51 according to the change value of the liquid level. When the sewage discharge volume of the bottom sewage outlet 51 exceeds the first set value, the bottom sewage outlet 51 is closed. Figure 2 The control model shown can achieve the sewage discharge effect and adjust the concentration of dissolved substances in the liquid in the generator shell to achieve the purpose of controlling water quality. However, Figure 2 The control model shown cannot achieve quantitative control. If the water quality of the liquid from the water replenishment port 10 deviates far from the ideal water quality range required for the steam generation process, that is, the concentration of dissolved substances in the replenishment liquid exceeds the concentration of dissolved substances in the liquid allowed by the steam generation process, it is difficult to adjust the water quality control of the steam generator back to the ideal water quality range. Therefore, Figure 2 The control model shown is suitable for roughly regulating liquids that do not deviate much from the ideal water quality range.

[0093] Figure 4 Another control model provided by the embodiment of the present invention is shown. This model is a preferred solution in the embodiment of the present invention. For the steam generation process, Figure 2 The control model shown is consistent, the liquid to be evaporated enters the generator housing 10 through the water replenishment port 30 in the X direction, is converted into steam under the action of the heat exchange device 20, rises in the Y direction to the steam outlet 40 and enters the subsequent equipment.

[0094] For water quality control process, Figure 4 In the middle sewage outlet, a water quality sensor 522 and a middle sewage outlet valve 521 with adjustable opening are provided. The liquid passing through the middle sewage outlet along the W direction will be sampled and tested for water quality parameters at the water quality sensor 522 before being discharged; Figure 4 In the control model shown, the gas-liquid separation device 70 is used to prevent bubbles generated by boiling on the surface of the heat exchange device 20 from entering the middle sewage outlet 52, affecting the sewage discharge efficiency of the middle sewage outlet 52 and the water quality detection accuracy of the water quality sensor 522.

[0095] like Figure 4 As shown, conductivity is used as a representative water quality parameter. Figure 4In the control model shown, when the water quality sensor 522 detects that the conductivity increases and exceeds the preset conductivity threshold, the control system will control the intermediate drain outlet valve 521 to open wider, increase the discharge volume of the middle drain outlet 52, and reduce the concentration ratio of the liquid in the steam generator; when the water quality sensor 522 detects that the conductivity drops to the preset conductivity threshold, the control system will control the intermediate drain outlet valve 521 to open narrower, reduce the discharge volume of the intermediate drain outlet 52, and reduce the heat lost during the drain and liquid discharge operation during the steam generation process. While the control system is controlling the opening of the middle sewage outlet valve 521, it will also adjust the water replenishment port valve 31 according to the liquid level detected by the liquid level meter 60, thereby controlling the amount of replenished liquid; when the liquid level is higher than the set distance of the middle sewage outlet, the control system will control the opening of the water replenishment port valve 313 to reduce the amount of replenished liquid. The set distance here is set according to the actual situation, and is preferably 0. Considering that the liquid level will fluctuate due to the outflow of bubbles during the steam generation process, there will be an error between the liquid level detected by the liquid level meter and the actual liquid level. Therefore, according to the actual situation, the set distance can be set to be slightly higher than the upper edge of the middle sewage outlet. It should be noted that the set distance cannot be The pressure relief valve 314 is too high to avoid the phenomenon of liquid inhalation. Liquid inhalation means that in the subsequent steam extraction equipment, the gas inhaled by the steam extraction equipment contains a certain amount of liquid. This phenomenon will affect the normal operation and efficiency of the steam extraction equipment. When the liquid level is lower than the set distance of the middle sewage outlet, the control system will control the opening of the water replenishment port valve 313 to increase, so that the amount of replenished liquid increases. Also based on the reason of bubble outburst, the set distance here is set according to the actual situation. The set distance is set to be slightly lower than the end face of the second baffle of the gas-liquid separation device 70 away from the first baffle. It should be noted that the set distance cannot be too low to avoid the liquid in the steam generator shell being unable to completely immerse the heat exchange device 20, causing the heat exchange device 20 to burn dry.

[0096] like Figure 4 As shown, the control system controls the opening of both the water replenishment port valve 31 and the middle sewage outlet valve 521, thereby realizing the control of the amount of liquid in the generator shell 10, so that the liquid level is maintained at the position of the middle sewage outlet 52. At this time, the steam generator can continuously discharge sewage during the steam generation process, and the rate at which the dirt floating on the liquid surface is continuously discharged is higher than the rate at which the liquid generates floating dirt, so that the floating dirt in the steam generator shell is reduced. At the same time, the concentration of the dissolved substance in the liquid in the generator shell is maintained within a limited range under the joint action of the sewage discharge operation at the middle sewage outlet 52 and the liquid replenishment operation at the water replenishment port 30, and does not increase significantly due to the evaporation process.

[0097] like Figure 4As shown, before the liquid level in the generator housing enters and is maintained at the middle drain outlet 52, the detection value of the water quality sensor 522 will not change suddenly, that is, when the liquid fills the middle drain outlet 52, the water quality parameters detected by the water quality sensor 522 change slowly, or when the liquid level has not yet overflowed the second baffle 72 and the liquid cannot enter the middle drain outlet 52, the water quality sensor cannot take samples and cannot detect the water quality parameters. If in the above case, the control system adjusts the water replenishment port valve 31 or the middle sewage outlet valve 521 to allow the liquid and air to mix and enter the middle sewage outlet 52, then the water quality parameter detected by the water quality sensor will undergo a sudden change, that is, a change greater than the preset threshold will occur within the set time, and the control system will believe that the middle sewage outlet of the steam generator has started to discharge sewage and liquid. In order to maintain the drainage process for a longer period of time, the control system will adjust the opening of the water replenishment port valve 31 to restore it to the opening before the middle sewage outlet valve 521 is opened; through the above settings, the changing trend of the supplementary liquid entering the generator housing 10 through the water replenishment port 30 is opposite to the changing trend of the liquid level at the middle sewage outlet, thereby slowing down the change rate of the liquid level at the middle sewage outlet.

[0098] like Figure 4 As shown, corresponding to the middle sewage outlet, at every predetermined period, the control system will open the bottom sewage outlet valve 511 to open the bottom sewage outlet 51, and at the same time, the control system will control the middle sewage outlet 52 to be closed, so that the dirt settled at the bottom of the generator shell 10 can be discharged along the Z direction. During this period, the liquid level meter 60 records the change in the liquid level of the liquid in the generator shell 10, and the control system calculates the displacement of the bottom sewage outlet 51. When the bottom sewage outlet 51 is opened and its displacement reaches the first set amount, the control system will close the bottom sewage outlet valve 511 and control the bottom sewage outlet 51 to be closed.

[0099] In an embodiment of the present invention, a steam generator water quality control method is provided, and in combination with the steam generator provided in the embodiment of the present invention, the openings of the corresponding water replenishment port valve and the middle sewage outlet valve are adjusted according to the liquid level in the generator shell and the water quality parameters of the liquid entering the middle sewage outlet, thereby adjusting the amount of replenished liquid and the amount of discharged liquid, thereby achieving the discharge of liquid dirt in the steam generator and the control of the concentration of dissolved substances in the body, thereby achieving the control of the water quality of the steam generator. The water quality sensor is combined with the gas-liquid separation device to avoid the interference of boiling bubbles on sampling detection, so that the present invention can accurately measure the water quality parameters of the water sample, and timely feedback the control system through accurate parameters to achieve the purpose of accurately controlling the water quality; the steam generator and the steam generator water quality control method provided by the embodiment of the present invention can achieve accurate sewage discharge and achieve the purpose of automatic water quality control without shutting down the steam generator, which has little impact on the basic steam generation function of the steam generator and can enable the steam generator to continue to operate efficiently. Furthermore, the control components involved in the embodiment of the present invention are relatively few, the logic is simple, and it is easy to produce and deploy; in general, the present invention realizes water quality control of the steam generator at a relatively low cost and a relatively high level of automation.

[0100] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, rather than to describe a specific order or precedence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0101] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A steam generator, characterized in that: The steam generator comprises: Generator shell, heat exchange device, water supply port, steam outlet, and sewage outlet; The heat exchange device is arranged inside the generator shell, the water replenishment port is arranged at the bottom of the generator shell, and the steam outlet is arranged at the top of the generator shell; The sewage outlet has two states of open and closed, and the sewage outlet includes a bottom sewage outlet and a middle sewage outlet; the bottom sewage outlet is arranged at the bottom of the generator shell and is staggered with the water replenishment port; the middle sewage outlet is arranged on the side wall of the generator shell.

2. The steam generator according to claim 1, characterized in that: A gas-liquid separation device is provided at the connecting position between the generator shell and the central sewage outlet. The gas-liquid separation device consists of a first baffle and a second baffle connected vertically to each other. The side of the first baffle facing away from the second baffle is connected to the bottom of the central sewage outlet, and the second baffle faces the central sewage outlet. The lengths of the first baffle and the second baffle are both greater than the diameter of the central sewage outlet.

3. The steam generator according to claim 1, characterized in that: A liquid level gauge is provided on the outside of the generator shell, one end of the liquid level gauge is connected to the bottom of the generator shell and is located near the water replenishment port, and the other end of the liquid level gauge is connected to the top of the generator shell; the liquid level gauge is used to detect the liquid level height of the liquid inside the generator shell, and the measuring range of the liquid level gauge covers the control range of the liquid level height of the liquid inside the generator shell.

4. The steam generator according to claim 1, characterized in that: The central sewage outlet is provided with a valve with adjustable opening and a water quality sensor; the water quality sensor is used to detect the water quality parameters of the liquid entering the central sewage outlet.

5. The steam generator according to claim 1, characterized in that: The heat exchange device comprises a plurality of heat exchange tubes, which are laid in parallel and evenly spaced on the inner bottom layer of the generator shell to form a heat exchange tube bundle, and the height of the heat exchange tube bundle is lower than the middle sewage outlet.

6. A method for controlling water quality of a steam generator, applied to the steam generator according to any one of claims 1 to 5, characterized in that: The method comprises: Open the water replenishment port to replenish liquid into the generator shell, and obtain the liquid level height of the liquid inside the generator shell and the water quality parameters of the liquid entering the middle sewage outlet; Controlling the valve opening of the water replenishment port according to the liquid level, and controlling the valve opening of the middle sewage outlet according to the water quality parameter, so that the difference between the liquid level of the liquid inside the generator housing and the height of the middle sewage outlet is less than or equal to a preset threshold; The bottom drain outlet is opened at a preset period, and after it is detected that the bottom drain outlet discharges a first set amount of liquid, the bottom drain outlet is closed.

7. The method according to claim 6, characterized in that The step of controlling the valve opening of the water replenishment port according to the liquid level comprises: When the liquid level meter detects that the liquid level is higher than the middle sewage outlet, the valve opening of the water supply outlet is controlled to decrease; When the liquid level meter detects that the liquid level is lower than the middle sewage outlet, the valve opening of the water replenishment outlet is controlled to increase.

8. The method according to claim 6, characterized in that The step of controlling the valve opening of the middle sewage outlet according to the water quality parameter comprises: When the water quality sensor detects that the water quality parameter rises and exceeds a preset water quality threshold, the valve opening of the middle sewage outlet is controlled to increase; When the water quality sensor detects that the water quality parameter is equal to the preset water quality threshold, the valve opening of the middle sewage outlet is controlled to decrease.

9. The method according to claim 6, characterized in that After the step of controlling the valve opening of the water replenishment port according to the liquid level and controlling the valve opening of the middle sewage outlet according to the water quality parameter, the method further includes: When the water quality sensor detects that the water quality parameter is less than the set value of the water quality parameter, the middle sewage outlet is controlled to be closed.

10. The method according to claim 6, characterized in that After the step of controlling the valve opening of the water replenishment port according to the liquid level and controlling the valve opening of the middle sewage outlet according to the water quality parameter, the method further includes: When the liquid level meter detects that the middle sewage outlet discharges a second set amount of liquid, the middle sewage outlet is controlled to be closed.

11. The method according to claim 6, characterized in that After the step of controlling the valve opening of the water replenishment port according to the liquid level and controlling the valve opening of the middle sewage outlet according to the water quality parameter, the method further includes: When the water quality sensor detects that the water quality parameter changes by more than a preset threshold value within a set time, the valve of the water replenishment port is restored to an initial opening.

12. The method according to claim 6, characterized in that The step of opening the bottom drain outlet at every preset period and closing the bottom drain outlet after detecting that the bottom drain outlet discharges a first set amount of liquid comprises: While the bottom sewage outlet is opened, the middle sewage outlet is controlled to be closed.

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