Drainage pipeline anti-corrosion device, heat supply system and drainage pipeline anti-corrosion method

Abstract

The invention discloses a drain pipeline anti-corrosion device, a heat supply system and a drain pipeline anti-corrosion method. The drain pipeline anti-corrosion device comprises a control unit, an oxygen busbar and a gas flow pump. A data acquisition end of the control unit is connected with a data sending end of the gas flow pump and is used for acquiring a flow signal of the gas flow pump; the output end of the control unit is connected with the control end of the gas flow pump and used for controlling the opening degree of the gas flow pump. The output end of the oxygen busbar is connected with the input end of the gas flow pump, and the output end of the gas flow pump is connected with an inlet of a drain pipe of the heating network heater. The air outlet of the drainage pipeline device is connected with the inlet of the drainage pipe of the heating network heater, and oxygen input by oxygen confluence is introduced into the drainage pipe of the heating network heater, so that the oxygen content in the drainage pipeline is increased, a compact oxidation protection layer is favorably formed in the drainage pipeline, electrochemical reaction in the drainage pipeline is hindered, and the drainage effect of the heating network heater is improved. And flow accelerated corrosion of the drainage pipeline is inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of power station systems, and in particular to a drainage pipeline anti-corrosion device, a heating system and a drainage pipeline anti-corrosion method. Background Art

[0002] Among the pipeline failure risks faced by nuclear power plants and large power plants in the existing technology, flow-accelerated corrosion ranks first, and pipelines experiencing flow-accelerated corrosion account for about 33% of the pipelines in power plants.

[0003] Flow-accelerated corrosion is a metal loss phenomenon caused by the combined action of electrochemical corrosion and physical erosion corrosion processes such as diffusion, mass transfer and deposition of corrosion products. The electrochemical process includes the ionization of the metal matrix Fe, the formation and chemical dissolution of the oxide film on the metal matrix surface. First, the magnetic oxide film on the surface of the metal matrix is ​​loose and porous. The metal matrix contacts the aqueous solution, and the metal matrix Fe forms a galvanic cell with the aqueous solution. Fe is ionized and loses electrons to generate Fe 2+ , part of Fe 2+ It reacts chemically with a small amount of Fe in the metal matrix under the action of an aqueous solution oxidant to form a magnetic Fe3O4 oxide film. The Fe3O4 oxide film is permeable and slightly soluble, and will chemically dissolve in water, causing the thickness of the oxide film to become thinner and the gap to increase, weakening the protective effect on the metal matrix of the pipeline, while enhancing the ionization of the metal matrix Fe, thinning the pipe wall, and accelerating the flow and corrosion rate.

[0004] Under the influence of flow-accelerated corrosion, the oxide protective film on the surface of the pipeline continues to dissolve and become thinner under the mainstream medium, resulting in a continuous decrease in the protective effect and increased corrosion, which is mainly manifested in accelerated pipeline scaling rate, valve blockage, increased pipeline pressure difference and thinning of the metal matrix. In severe cases, it will cause pipeline burst accidents, leakage of high-temperature working fluids, and unplanned shutdown of units, resulting in huge economic losses. Summary of the invention

[0005] The invention provides a drainage pipeline anti-corrosion device, a heating system and a drainage pipeline anti-corrosion method, so as to slow down or avoid flow-accelerated corrosion in the drainage pipeline.

[0006] According to one aspect of the present invention, there is provided a drainage pipeline anti-corrosion device, comprising: a control unit, an oxygen bus and a gas flow pump;

[0007] The data acquisition end of the control unit is connected to the data sending end of the gas flow pump, so as to obtain the flow signal of the gas flow pump;

[0008] The output end of the control unit is connected to the control end of the gas flow pump, and is used to control the opening of the gas flow pump;

[0009] The output end of the oxygen bus is connected to the input end of the gas flow pump, and the output end of the gas flow pump is connected to the inlet of the drain pipe of the heating network heater.

[0010] Optionally, the drainage pipe anti-corrosion device further includes: an electric valve;

[0011] The first end of the electric valve is connected to the output end of the gas flow pump, and the second end of the electric valve is connected to the inlet of the drain pipe of the heating network heater;

[0012] The control end of the electric valve is connected to the output end of the control unit.

[0013] Optionally, the drainage pipeline anti-corrosion device further includes: a check valve;

[0014] The first end of the check valve is connected to the output end of the gas flow pump, and the second end of the check valve is connected to the second end of the electric valve.

[0015] Optionally, the drain pipe anti-corrosion device further includes: a back pressure valve;

[0016] The first end of the back pressure valve is connected to the output end of the gas flow pump, and the second end of the back pressure valve is connected to the second end of the electric valve.

[0017] Optionally, the drainage pipeline anti-corrosion device further includes: a buffer tank;

[0018] The first end of the buffer tank is connected to the output end of the oxygen bus, and the second end of the buffer tank is connected to the input end of the gas flow pump.

[0019] According to another aspect of the present invention, there is provided a heating system, comprising: a medium pressure cylinder, a heating network heater, a return water network, and a drainage pipe anti-corrosion device according to any embodiment of the present invention;

[0020] The air extraction end of the medium pressure cylinder is connected to the air inlet of the heat network heater, and the first end of the return water network is connected to the return water inlet end of the heat network heater;

[0021] The drain outlet of the heat network heater is connected to the output end of the gas flow pump of the drain pipe anti-corrosion device and the inlet of the heat recovery system, and the return water outlet of the heat network heater is connected to the second end of the return water network.

[0022] According to another aspect of the present invention, a method for anti-corrosion of a drain pipe is provided, which is applied to the anti-corrosion device for a drain pipe provided in any embodiment of the present invention, and the method comprises:

[0023] Obtaining the set target dissolved oxygen value in the drainage pipeline anti-corrosion device;

[0024] Obtaining drainage parameters in the drainage pipeline;

[0025] Obtaining a target flow rate of a gas flow pump in a drainage pipeline anti-corrosion device according to the set target dissolved oxygen value and the drainage parameter;

[0026] The opening degree of the gas flow pump is controlled according to the target flow rate of the gas flow pump.

[0027] Optionally, the obtaining of drainage parameters in the drainage pipeline includes:

[0028] The obtaining of the drainage parameters in the drainage pipeline comprises:

[0029] Obtain the dissolved oxygen meter parameter signal at the end of the heating network heater drain system, and obtain the flow parameter signal of the heating network heater drain pump.

[0030] Optionally, obtaining the target flow rate of the gas flow pump in the drainage pipeline anti-corrosion device according to the set target dissolved oxygen value and the drainage parameter includes:

[0031] The set target dissolved oxygen value and the drain parameter are input into the oxygenation control model, and the output result of the oxygenation control model is the target flow rate of the gas flow pump in the drain pipe anti-corrosion device;

[0032] The expression of the oxygenation control model includes:

[0033]

[0034] Among them, Q2 is the flow value of the gas flow pump, K1 is the proportional coefficient, M2 is the parameter value of the dissolved oxygen table at the end of the heat network heater drain system, M1 is the target dissolved oxygen value set by the drain pipe anti-corrosion device, K2 is the constraint coefficient, and Q1 is the flow value of the heat network heater drain pump.

[0035] Optionally, after controlling the opening of the gas flow pump according to the target flow of the gas flow pump, the method further includes:

[0036] The oxygen content value or steam hydrogen conductivity value of the heat network heater drain is obtained, and when the oxygen content value or steam hydrogen conductivity value of the heat network heater drain is greater than a preset threshold value, the gas flow pump is controlled to be closed.

[0037] In the drain pipe anti-corrosion device, heating system and drain pipe anti-corrosion method of the embodiment of the present invention, in the drain pipe anti-corrosion device, the oxygen bus provides an oxygen source for the drain pipe anti-corrosion device, and the oxygen provided by the oxygen bus is input into the gas flow pump, and the control unit controls the opening of the gas flow pump to pass a certain amount of oxygen into the inlet of the heat network heater drain pipe. In the embodiment of the present invention, oxygen is passed into the drain pipe to increase the oxygen content in the drain pipe. It is helpful to form a dense oxide protective layer in the drain pipe, hinder the electrochemical reaction in the drain pipe, and inhibit the flow-accelerated corrosion of the drain pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 A drainage pipe anti-corrosion device provided by an embodiment of the present invention;

[0040] Figure 2 Another anti-corrosion device for drain pipes provided in an embodiment of the present invention;

[0041] Figure 3 Another anti-corrosion device for drain pipes provided in an embodiment of the present invention;

[0042] Figure 4 A heating system provided by an embodiment of the present invention;

[0043] Figure 5 A method for preventing corrosion of a drainage pipe provided by an embodiment of the present invention;

[0044] Figure 6 Another anti-corrosion method for drain pipes provided by an embodiment of the present invention;

[0045] Figure 7 Another anti-corrosion method for a drain pipe is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0047] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0048] Figure 1 A drainage pipe anti-corrosion device provided by an embodiment of the present invention, such as Figure 1 As shown, the drain pipe anti-corrosion device provided by the embodiment of the present invention includes: a control unit 101, an oxygen bus 102 and a gas flow pump 103; the data acquisition end of the control unit 101 is connected to the data sending end of the gas flow pump 103, for obtaining the flow signal of the gas flow pump 103; the output end of the control unit 101 is connected to the control end of the gas flow pump 103, for controlling the opening of the gas flow pump 103; the output end of the oxygen bus 102 is connected to the input end of the gas flow pump 103, and the output end of the gas flow pump 103 is connected to the inlet of the drain pipe of the heat network heater.

[0049] Specifically, Figure 1 As shown, in the anti-corrosion device for drain pipes, the oxygen bus 102 is an oxygen supply device for storing and distributing oxygen. The oxygen bus 102 delivers oxygen to the gas flow pump 103 so as to further control its flow rate. The gas flow pump 103 is a flow control device for adjusting the flow rate of oxygen. The gas flow pump 103 receives oxygen from the oxygen bus 102 and adjusts its opening according to the instruction of the control unit 101, thereby controlling the amount of oxygen entering the inlet of the drain pipe of the heat network heater. The data acquisition end of the control unit 101 collects the flow signal of the gas flow pump 103 to adjust the opening of the gas flow pump 103 according to the real-time flow data of the gas flow pump 103.

[0050] The flow-accelerated corrosion rate of pipelines is mainly affected by factors such as the shape, material, environment of the pipeline, pH, conductivity, and oxygen content of the working fluid. The iron ion content in the working fluid can directly reflect the flow-accelerated corrosion rate of the pipeline. The increase in oxygen content can effectively inhibit flow-accelerated corrosion. When the hydrogen conductivity of the heat network heater hydrophobicity is less than 0.15μS / cm (the target value is 0.1μS / cm), the hydrophobic pipeline is prone to flow-accelerated corrosion. The hydrophobic pipeline anti-corrosion device adds oxygen to the inlet of the heat network heater hydrophobic pipe to increase the dissolved oxygen mass concentration of the hydrophobicity and increase the pH value of the hydrophobicity, thereby producing a metal passivation effect on the metal surface of the pipeline, forming a double-layer oxide film on the metal surface, the inner layer is a magnetic Fe3O4 oxide film close to the surface of the metal substrate, and the outer layer is a dense protective layer of Fe2O3 and hydrated iron oxide oxide film. The dense oxide film hinders the electrochemical reaction and reduces the Fe 2+ diffusion, reducing the flow accelerated corrosion rate.

[0051] In an embodiment of the present invention, a drain pipe anti-corrosion device is provided, wherein an oxygen bus provides an oxygen source for the drain pipe anti-corrosion device, and the oxygen provided by the oxygen bus is input into a gas flow pump, and a control unit controls the opening of the gas flow pump to introduce a certain amount of oxygen into the inlet of the drain pipe of the heating network heater. In an embodiment of the present invention, oxygen is introduced into the drain pipe to increase the oxygen content in the drain pipe. This helps to form a dense oxide protective layer in the drain pipe, hinders the electrochemical reaction in the drain pipe, and inhibits the flow-accelerated corrosion of the drain pipe.

[0052] Based on the above embodiments, Figure 2 Another anti-corrosion device for drain pipes provided by an embodiment of the present invention is as follows: Figure 2 As shown, the drain pipe anti-corrosion device provided in an embodiment of the present invention also includes: an electric valve 104; the first end of the electric valve 104 is connected to the output end of the gas flow pump 103, and the second end of the electric valve 104 is connected to the inlet of the heat network heater drain pipe; the control end of the electric valve 104 is connected to the output end of the control unit 101.

[0053] Specifically, in the drainage pipe anti-corrosion device, an electric valve 104 is provided between the drainage pipe inlet of the heating network heater and the output end of the gas flow pump 103. The electric valve 104 can be turned on or off according to the control signal of the control unit 101.

[0054] When oxygen is passed through the drain pipe, the surface of the sediment layer of the drain pipe is converted into stable Fe2O3, and the micropores of the Fe3O4 film layer are blocked, making the protective layer denser, so that a uniform and dense Fe2O3+Fe3O4 double-layer protective film is formed on the carbon steel surface, thereby inhibiting the flow of the drain system to accelerate corrosion. At the same time, the addition of an oxidant causes the carbon steel potential to reach the Fe2O3 passivation zone from the magnetic Fe3O4 stable zone, thereby generating a dense and stable protective oxide film on the metal surface. However, when the amount of oxygen passed into the drain pipe is too high, oxygen, as a strong oxidant, will accelerate the oxidation reaction of the metal material, resulting in an increase in the corrosion rate of the equipment. At the same time, when the oxygen content in the drain pipe is too high and the protective oxide film generated on the metal surface is too thick, the oxides and other sediments in the pipe are more likely to accumulate in the pipe to block the pipe, affecting the normal flow of the drain, and even causing the system to fail.

[0055] The electric valve 104 is arranged between the inlet of the heat network heater drain pipe and the output end of the gas flow pump 103. When the control unit 101 detects that the oxygen content of the heat network heater drain or the steam hydrogen conductivity is greater than a preset threshold value, the electric valve 104 is closed and the drain pipe anti-corrosion device stops supplying oxygen to the drain pipe.

[0056] In the drain pipe anti-corrosion device provided in the embodiment of the present invention, an electric valve is arranged between the drain pipe inlet of the heat network heater and the output end of the gas flow pump to control the drain pipe anti-corrosion device to ensure that the oxygen flow rate in the drain pipe is within a preset threshold value, which is beneficial to ensure that oxygen is introduced into the drain at an appropriate flow rate and concentration, and is beneficial to strictly control the oxygen content, ensuring the safe, stable and efficient operation of the system.

[0057] Based on the above embodiments, Figure 3 Another anti-corrosion device for drain pipes provided by an embodiment of the present invention is as follows: Figure 3 As shown, the anti-corrosion device for drain pipes provided in the embodiment of the present invention further includes: a check valve 105; the first end of the check valve 105 is connected to the output end of the gas flow pump 103, and the second end of the check valve 105 is connected to the second end of the electric valve 104. The anti-corrosion device for drain pipes further includes: a back pressure valve 106; the first end of the back pressure valve 106 is connected to the output end of the gas flow pump 103, and the second end of the back pressure valve 106 is connected to the second end of the electric valve 104. The anti-corrosion device for drain pipes further includes: a buffer tank 107; the first end of the buffer tank 107 is connected to the output end of the oxygen bus 102, and the second end of the buffer tank 107 is connected to the input end of the gas flow pump 103.

[0058] Specifically, in the drain pipe protection device, the check valve 105 is located between the gas flow pump 103 and the electric valve 104, and the check valve 105 is used to prevent the drain in the drain pipe from flowing back into the drain pipe anti-corrosion device.

[0059] The back pressure valve 106 is located between the electric valve 104 and the gas flow pump 103. The back pressure valve 106 is used to control the pressure at the output end of the gas flow pump 103 to ensure that oxygen can be stably and input into the drain pipe at an appropriate pressure. When oxygen is pressurized and transmitted by the gas flow pump 103, the oxygen will directly impact the drain pipe because of the excessive pressure. This will not only damage the pipeline, but also affect the uniform distribution and dissolution effect of oxygen. By adjusting the opening of the back pressure valve 106, back pressure can be generated. The back pressure generated by the back pressure valve 106 is conducive to maintaining the pressure stability at the outlet of the gas flow pump 103.

[0060] The buffer tank 107 is located between the oxygen bus 102 and the gas flow pump 103. When oxygen flows out of the oxygen bus 102, passes through the buffer tank 107, and then enters the gas flow pump 103, the buffer tank 107 can reduce the fluctuation of the oxygen pressure, making the operation of the gas flow pump 103 more stable. At the same time, since the buffer tank 107 has a certain volume inside, it can store a certain amount of oxygen and release it when needed. This feature enables the buffer tank 107 to assist the gas flow pump 103 in regulating the flow: when the oxygen flow needs to be increased, the buffer tank 107 can quickly provide additional oxygen; and when the flow needs to be reduced, the buffer tank 107 can slow down the release rate of oxygen.

[0061] Based on the above embodiments, Figure 4 A heating system provided by an embodiment of the present invention, such as Figure 4 As shown, the heating system provided by the embodiment of the present invention includes: a medium-pressure cylinder 02, a heating network heater 03, a return water network 04 and a drain pipe anti-corrosion device 01 of any embodiment of the present invention; the air extraction end of the medium-pressure cylinder 02 is connected to the air inlet of the heating network heater 03, and the first end of the return water network 04 is connected to the return water inlet end of the heating network heater 03; the drain outlet end of the heating network heater 03 is connected to the output end of the gas flow pump 103 of the drain pipe anti-corrosion device 01 and the inlet of the heat recovery system, and the return water outlet end of the heating network heater 03 is connected to the second end of the return water network 04.

[0062] Specifically, the intermediate pressure cylinder 02 is a component of the steam turbine unit, receiving the steam discharged from the high pressure cylinder and the reheated steam. In the heating system of the embodiment of the present invention, the exhaust end of the intermediate pressure cylinder 02 is used to provide steam for heating, and the steam output from the exhaust end of the intermediate pressure cylinder 02 is input to the air inlet of the heating network heater 03.

[0063] As a heat exchange device, the heat network heater 03 uses the steam extracted from the medium pressure cylinder 02 to heat the return water in the return water network 04. The steam releases heat in the heat network heater, which increases the return water temperature in the return water network 04 to meet the heating demand. The air inlet is the heat source inlet, and the return water inlet end of the heat network heater 03 is the return water input end in the return water network 04; the heat network heater 03 also has a drain outlet end and a return water outlet end. The drain outlet end discharges the drain generated during the heating process, and the return water outlet end outputs the heated high-temperature water.

[0064] The return water network 04 is a pipe network for circulating return water. The return water flows out from the heating area, is heated by the heating network heater, and then flows back to the heating area. The heating area includes the heating network users.

[0065] The heat recovery system into which the drain flows refers to a component of the thermal system in the power plant. Exemplarily, the heat recovery system includes: a condenser hot well or a low-pressure heater. The condenser hot well is used to collect condensate from the exhaust steam of the steam turbine. This condensate is collected and stored in the hot well for subsequent use. The low-pressure heater uses lower pressure steam to further heat the drain. As the drain flows through each heater, its temperature gradually increases. Finally, the drain is heated to a temperature close to or reaching a preset temperature and is sent to a boiler or other water-using equipment.

[0066] The drain outlet of the heating network heater 03 is used as an oxygenation point, and the output end of the gas flow pump 103 of the drain pipe anti-corrosion device 01 outputs oxygen to the drain outlet of the heating network heater 03, thereby increasing the oxygen content of the drain in the drain pipe to avoid flow-accelerated corrosion.

[0067] In the heating system provided by the embodiment of the present invention, the heat source of the heat network heater comes from the medium pressure cylinder of the steam turbine unit. After the heat network heater heats the return water in the return water network, the drain is discharged through the drain outlet of the heat network heater. The output end of the gas flow pump of the drain pipe anti-corrosion device is connected to the drain outlet of the heat network heater. The drain pipe anti-corrosion device oxygenates the drain pipe, which is conducive to the formation of a dense oxidation protection layer in the drain pipe, hinders the electrochemical reaction in the drain pipe, and inhibits the flow-accelerated corrosion of the drain pipe.

[0068] Based on the above embodiments, Figure 5 The present invention provides a method for preventing corrosion of a drain pipe. The present invention is applicable to preventing corrosion of the drain pipe caused by flow acceleration. The method for preventing corrosion of a drain pipe can be applied to the device for preventing corrosion of a drain pipe in any embodiment of the present invention. Figure 5 As shown, the anti-corrosion method for drain pipes provided by the embodiment of the present invention includes:

[0069] S201. Obtain a set target dissolved oxygen value in a drain pipe anti-corrosion device.

[0070] Specifically, Figures 1 to 5 In the embodiment, the anti-corrosion device 01 of the drain pipe is set to set a target dissolved oxygen value. The specific value of the target oxygen content is determined by the actual operation of the power plant. Optionally, the target dissolved oxygen value is set between 20 and 80 μg / L. Setting the target dissolved oxygen value can provide enough oxygen for the drain pipe to form a dense oxide film to avoid accelerated corrosion of the flow of the drain pipe; at the same time, it can also avoid problems such as excessively thick oxide layer and intensified corrosion reaction caused by excessive oxygen.

[0071] S202: Obtain drainage parameters in the drainage pipeline.

[0072] Specifically, the drainage parameters in the drainage pipeline include: the dissolved oxygen meter value at the end of the heating network heater drainage system and the flow value of the heating network heater drainage pump.

[0073] Exemplarily, the sensor or instrument on the drain pipe obtains the dissolved oxygen meter signal at the end of the heat network heater drain system and the flow signal of the heat network heater drain pump. The dissolved oxygen meter value at the end of the heat network heater drain system and the flow value of the heat network heater drain pump reflect the actual oxygen content in the drain pipe and the flow rate of the drain.

[0074] S203, obtaining a target flow rate of a gas flow pump in a drainage pipeline anti-corrosion device according to the set target dissolved oxygen value and drainage parameters.

[0075] Calculate and determine the oxygen flow rate that the gas flow pump needs to provide to achieve the set target dissolved oxygen value. Optionally, calculate the target flow rate of the gas flow pump based on the target dissolved oxygen value, the actual dissolved oxygen value and the drain flow value through an algorithm or model.

[0076] S204: Control the opening of the gas flow pump according to the target flow of the gas flow pump.

[0077] Specifically, according to the target flow rate of the gas flow pump, the control unit 101 adjusts the opening of the gas flow pump 103 so that the actual oxygen flow rate matches the target flow rate.

[0078] In the anti-corrosion method for drain pipes of the embodiment of the present invention, accurate control of the amount of oxygen passed into the drain pipe by the anti-corrosion device for drain pipes is achieved by setting a target dissolved oxygen value, obtaining drain parameters, calculating a target flow rate, and controlling the opening of a gas flow pump. This method helps prevent flow-accelerated corrosion in the drain pipe and improves the operating efficiency and safety of the power plant.

[0079] Based on the above embodiments, Figure 6 Another anti-corrosion method for drain pipes provided by an embodiment of the present invention is as follows: Figure 6As shown, the anti-corrosion method for drain pipes provided in the embodiment of the present invention also includes:

[0080] S301. Obtain a set target dissolved oxygen value in a drain pipe anti-corrosion device.

[0081] S302, obtaining a dissolved oxygen meter parameter signal at the end of the heat network heater drain system, and obtaining a flow parameter signal of a heat network heater drain pump.

[0082] Specifically, the dissolved oxygen meter parameter signal at the end of the heat network heater drain system reflects the dissolved oxygen level at the end of the drain pipe (ie, the outlet of the heat network heater drain system). The heat network heater drain pump flow parameter signal represents the flow of the drain pump, ie, the water flow rate in the drain pipe.

[0083] S303, setting a target dissolved oxygen value and drain parameters and inputting them into an oxygenation control model, the output result of the oxygenation control model is a target flow rate of a gas flow pump in the drain pipe anti-corrosion device.

[0084] Among them, the expression of the oxygen addition control model includes:

[0085]

[0086] Among them, Q2 is the flow value of the gas flow pump, K1 is the proportional coefficient, M2 is the parameter value of the dissolved oxygen table at the end of the heat network heater drain system, M1 is the target dissolved oxygen value set by the drain pipe anti-corrosion device, K2 is the constraint coefficient, and Q1 is the flow value of the heat network heater drain pump.

[0087] Specifically, the proportional coefficient K1 and the constraint coefficient K2 are set manually according to the actual situation. The proportional coefficient K1 adjusts the difference between the set target dissolved oxygen value (hereinafter referred to as the target value) and the dissolved oxygen meter parameter value at the end of the heat network heater drain system (hereinafter referred to as the actual value), which is the adjustment ratio of the gas flow meter flow control. The constraint coefficient K2 controls the actual value to be stable near the target value.

[0088] For example, for a unit with a relatively stable drain flow rate of a heating network heater, the setting value of the corresponding proportional coefficient K1 is relatively large and the setting value of the constraint coefficient K2 is relatively small. The larger proportional coefficient K1 is because the stable flow rate means that a smaller adjustment is required to maintain the dissolved oxygen value within the target range; the setting value of the constraint coefficient K2 can be relatively small because the system itself is relatively stable. At this time, the drain flow rate changes little, and the gas flow pump flow value Q2 tends to be stable.

[0089] When the flow fluctuation of the heat network heater drain is relatively large, the setting value of the corresponding proportional coefficient K1 is relatively small and the setting value of the constraint coefficient K2 is relatively large. Due to the drastic changes in the actual value and the target value caused by the flow fluctuation, the smaller the proportional coefficient K1, the smaller the difference between the actual value and the target value, so as to reduce the direct impact of the flow fluctuation on the dissolved oxygen value control; the larger the constraint coefficient K2 value, the better the return to neutrality when the actual value deviates greatly from the target value, and the better stability when the actual value is close to the target value.

[0090] S304: Control the opening of the gas flow pump according to the target flow of the gas flow pump.

[0091] Based on the above embodiments, Figure 7 Another anti-corrosion method for drain pipes provided by an embodiment of the present invention is as follows: Figure 7 As shown, the anti-corrosion method for drain pipes provided in the embodiment of the present invention also includes:

[0092] S401, obtaining a set target dissolved oxygen value in a drain pipe anti-corrosion device.

[0093] S402: Obtain drainage parameters in the drainage pipeline.

[0094] S403, obtaining a target flow rate of a gas flow pump in a drainage pipeline anti-corrosion device according to the set target dissolved oxygen value and drainage parameters.

[0095] S404: Control the opening of the gas flow pump according to the target flow of the gas flow pump.

[0096] S405, obtaining the oxygen content value or steam hydrogen conductivity value of the heat network heater drain, and when the oxygen content value or steam hydrogen conductivity value of the heat network heater drain is greater than a preset threshold, controlling the gas flow pump to close.

[0097] Specifically, when the oxygen content in the drain of the heating network heater is too high, the excessive oxygen in the drain will react with the metal equipment to cause oxidation, which will accelerate the corrosion of the equipment. When the hydrogen conductivity of the drain is high, the ion content in the system is high, which will also accelerate the oxygen evolution corrosion of the iron of the pipeline matrix. Therefore, the preset thresholds of the oxygen content value and steam hydrogen conductivity value of the drain of the heating network heater are set. The oxygen content value or steam hydrogen conductivity value of the drain of the heating network heater is collected in real time and compared with the preset threshold value; when the oxygen content value or steam hydrogen conductivity value of the drain of the heating network heater is greater than the preset threshold value, the gas flow pump is controlled to be closed.

[0098] Optionally, the preset threshold value of the oxygen content value of the heat network heater drain is 80 μg / L; the preset threshold value of the steam hydrogen conductivity value is 0.15 μS / cm.

[0099] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0100] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A drainage pipe anti-corrosion device, characterized in that: include: Control unit, oxygen bus and gas flow pump; The data acquisition end of the control unit is connected to the data sending end of the gas flow pump, so as to obtain the flow signal of the gas flow pump; The output end of the control unit is connected to the control end of the gas flow pump, and is used to control the opening of the gas flow pump; The output end of the oxygen bus is connected to the input end of the gas flow pump, and the output end of the gas flow pump is connected to the inlet of the drain pipe of the heating network heater.

2. The drainage pipe anti-corrosion device according to claim 1, characterized in that: The drainage pipeline anti-corrosion device also includes: an electric valve; The first end of the electric valve is connected to the output end of the gas flow pump, and the second end of the electric valve is connected to the inlet of the drain pipe of the heating network heater; The control end of the electric valve is connected to the output end of the control unit.

3. The drainage pipe anti-corrosion device according to claim 2, characterized in that: The drainage pipeline anti-corrosion device also includes: a check valve; The first end of the check valve is connected to the output end of the gas flow pump, and the second end of the check valve is connected to the second end of the electric valve.

4. The drainage pipe anti-corrosion device according to claim 2, characterized in that: The drainage pipeline anti-corrosion device also includes: a back pressure valve; The first end of the back pressure valve is connected to the output end of the gas flow pump, and the second end of the back pressure valve is connected to the second end of the electric valve.

5. The drainage pipe anti-corrosion device according to claim 1, characterized in that: The drainage pipeline anti-corrosion device also includes: a buffer tank; The first end of the buffer tank is connected to the output end of the oxygen bus, and the second end of the buffer tank is connected to the input end of the gas flow pump.

6. A heating system, characterized in that: include: A medium pressure cylinder, a heating network heater, a return water network and a drainage pipe anti-corrosion device according to any one of claims 1 to 5 above; The air extraction end of the medium pressure cylinder is connected to the air inlet of the heat network heater, and the first end of the return water network is connected to the return water inlet end of the heat network heater; The drain outlet of the heat network heater is connected to the output end of the gas flow pump of the drain pipe anti-corrosion device and the inlet of the heat recovery system, and the return water outlet of the heat network heater is connected to the second end of the return water network.

7. A method for anti-corrosion of a drain pipe, applied to the anti-corrosion device of any one of claims 1 to 5, characterized in that: The method comprises: Obtaining the set target dissolved oxygen value in the drainage pipeline anti-corrosion device; Obtaining drainage parameters in the drainage pipeline; Obtaining a target flow rate of a gas flow pump in a drainage pipeline anti-corrosion device according to the set target dissolved oxygen value and the drainage parameter; The opening degree of the gas flow pump is controlled according to the target flow rate of the gas flow pump.

8. The method for anti-corrosion of drain pipes according to claim 7, characterized in that: The obtaining of the drainage parameters in the drainage pipeline comprises: Obtain the dissolved oxygen meter parameter signal at the end of the heating network heater drain system, and obtain the flow parameter signal of the heating network heater drain pump.

9. The method for anti-corrosion of drain pipes according to claim 8, characterized in that: The step of obtaining the target flow rate of the gas flow pump in the drainage pipeline anti-corrosion device according to the set target dissolved oxygen value and the drainage parameter comprises: The set target dissolved oxygen value and the drain parameter are input into the oxygenation control model, and the output result of the oxygenation control model is the target flow rate of the gas flow pump in the drain pipe anti-corrosion device; The expression of the oxygenation control model includes: Among them, Q2 is the flow value of the gas flow pump, K1 is the proportional coefficient, M2 is the parameter value of the dissolved oxygen table at the end of the heat network heater drain system, M1 is the target dissolved oxygen value set by the drain pipe anti-corrosion device, K2 is the constraint coefficient, and Q1 is the flow value of the heat network heater drain pump.

10. The method for anti-corrosion of drain pipe according to claim 7, characterized in that: After controlling the opening of the gas flow pump according to the target flow of the gas flow pump, the method further includes: The oxygen content value or steam hydrogen conductivity value of the heat network heater drain is obtained, and when the oxygen content value or steam hydrogen conductivity value of the heat network heater drain is greater than a preset threshold value, the gas flow pump is controlled to be closed.

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