A deaerator pressure control method

Abstract

The present invention provides a deaerator pressure control method, which relates to the field of deaerator pressure control. The deaerator pressure control method includes the following steps: S1. Before the operation of the deaerator, that is, before feeding water, high-pressure steam is introduced into the interior of the steam storage tank, and the state of non-connection is maintained between the steam storage tank and the outer shell of the deaerator; S2. Observe the gas pressure inside the steam storage tank. When the gas pressure is 1.4 - 2 times the standard pressure for the operation of the deaerator, water vapor is introduced into the interior of the deaerator, and the inlet pipe is opened to introduce water vapor with a stable flow rate; S3. Open the valve at the water inlet to allow the condensate water and make-up water to first enter the water chamber of the inner spiral film device group in the deaerator head. Through the steam storage tank, it is possible to quickly increase the gas to the specified pressure in the initial stage of operation, avoiding long waiting times, and by measuring the static pressure and dynamic pressure of each part, the response time of pressure stabilization is reduced, and the pressure stability is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of deaerator pressure control, and specifically to a deaerator pressure control method. Background Art

[0002] The deaerator is one of the key equipment in the boiler and heating system. If the deaeration capacity of the deaerator is poor, it will cause serious corrosion to the boiler feed water pipeline, economizer and other auxiliary equipment. Therefore, the State Power Ministry has put forward partial standards for the oxygen content in the deaerator, that is, the oxygen content in the feed water of the atmospheric deaerator should be less than 15 μg / L, and the oxygen content in the feed water of the pressure deaerator should be less than 7 μg / L. When the feed water is heated at a constant pressure, as the evaporation process proceeds, the amount of steam on the water surface continuously increases, and the partial pressure of the steam gradually rises. By discharging the gas in time, the partial pressures of various gases on the water surface continuously decrease. When the water is heated to the saturation temperature under the pressure of the deaerator, a large amount of water evaporates, and the partial pressure of the water vapor will approach the total pressure on the water surface. As the gas is continuously discharged, the partial pressures of various gases on the water surface will approach zero. Thus, the gases dissolved in the water will escape from the water and be removed. During the operation process, steam needs to be continuously introduced to make the pressure inside the deaerator head reach the operating pressure of the equipment. Summary of the Invention

[0003] (I) Technical Problems to be Solved

[0004] In view of the deficiencies of the prior art, the present invention provides a deaerator pressure control method, which solves the problems that the gas pressure reaches the threshold slowly in the initial stage of operation and fluctuates during the operation process, affecting the deaeration effect.

[0005] (II) Technical Solutions

[0006] To achieve the above object, the present invention is realized through the following technical solutions: A deaerator pressure control method includes the following steps:

[0007] S1. Before the operation of the deaerator, that is, before the feed water, high-pressure steam is introduced into the steam storage tank, and the steam storage tank and the outer shell of the deaerator are kept in a non-connected state;

[0008] S2. Observe the gas pressure inside the steam storage tank. When the gas pressure is 1.4 - 2 times the standard pressure for the operation of the deaerator, water vapor is introduced into the deaerator, and the inlet pipe is opened to introduce water vapor with a stable flow rate;

[0009] S3. Open the valve at the feed water inlet so that the condensate water and make-up water first enter the water chamber of the inner rotary film device group in the deaerator head, and under a certain water level differential pressure, spray obliquely from the small holes of the film tube into the inner hole to form a jet, and the water level differential pressure is one atmosphere;

[0010] S4. Open the valve between the steam storage tank and the deaerator, so that high-pressure gas quickly enters the interior of the deaerator housing, making the pressure reach the pressure required for the operation of the deaerator;

[0011] S5. Measure respectively through multiple pressure sensors the static pressure and dynamic pressure inside the deaerator housing, the static pressure and dynamic pressure inside the steam storage tank, and the total pressure inside the intake pipeline;

[0012] S6. According to the dynamic pressure indication inside the deaerator housing, obtain V1, and with the cross-sectional area S of the pipeline when the gas flows out of the deaerator housing, the volume V2 of the gas flowing out can be quickly calculated, and the volume of the pumped-in gas is quickly adjusted through the air pump at the input end of the steam storage tank;

[0013] S7. For the other steam inlet of the deaerator, that is, the intake pipe, it is carried out in a way of supplying gas with stable pressure by an air pump.

[0014] Preferably, a heat preservation layer is provided on the outer surface of the steam storage tank, and a heating device is provided inside the steam storage tank for maintaining the gas pressure inside the steam storage tank.

[0015] Preferably, for the heating steam rising in S4, a large amount of heating steam is sucked in by the water during the jet movement, and a strong mixing and heating effect is generated in a very short time and a very small stroke, the water temperature is greatly increased, and the rotating water continues to rotate downward along the inner wall of the membrane tube to form a tumbling water film skirt. At this time, the heat transfer and mass transfer effect of the water in the turbulent state is the best, and the water temperature reaches the saturation temperature.

[0016] Preferably, V1 = (2G / ρ) ½, V2 = V1 * S, where V1 is the gas flow rate, G is the static pressure, ρ is the density of water vapor, and V2 is the volume change of water vapor.

[0017] Preferably, the total pressure of the pressure sensor inside the intake pipeline in S5 is used to indicate whether the steam intake end is stable, and the static pressure inside the deaerator housing is the real-time pressure of water vapor.

[0018] (III) Beneficial effects

[0019] The present invention provides a method for controlling the pressure of a deaerator. It has the following beneficial effects:

[0020] 1. Through the steam storage tank, in the initial stage of operation, the gas can be quickly increased to the specified pressure, avoiding long-term waiting.

[0021] 2. By measuring the static pressure and dynamic pressure of each part, the response time of pressure stability is reduced, and the pressure stability is increased. Specific embodiments

[0022] The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] Embodiment 1:

[0024] The embodiment of the present invention provides a deaerator pressure control method, including the following steps:

[0025] S1. Before the operation of the deaerator, that is, before feeding water, high-pressure steam is introduced into the interior of the steam storage tank, and the steam storage tank and the outer shell of the deaerator are kept in a non-connected state. S2. Observe the gas pressure inside the steam storage tank. The outer surface of the steam storage tank is provided with a heat-insulating layer, and a heating device is arranged inside the steam storage tank to maintain the gas pressure inside the steam storage tank. When the gas pressure is 1.4 times the standard pressure for the operation of the deaerator, water vapor is introduced into the interior of the deaerator, and the inlet pipe is opened to introduce water vapor with a stable flow rate. S3. Open the valve at the water inlet to allow the condensate water and make-up water to first enter the water chamber of the inner spiral film device group in the deaerator head, and spray obliquely inward from the small holes of the film tube under a certain water level differential pressure to form a jet. The water level differential pressure is one atmospheric pressure. S4. Open the valve between the steam storage tank and the deaerator, and the high-pressure gas quickly enters the interior of the deaerator shell to make the pressure reach the pressure required for the operation of the deaerator. The rising heating steam is sucked in by the water in the jet movement, and a strong mixing and heating effect is generated in a very short time and a very small stroke, resulting in a large increase in the water temperature. The rotating water continues to swirl downward along the inner wall of the film tube to form a rolling water film skirt. At this time, the heat transfer and mass transfer effect of the turbulent water is the best, and the water temperature reaches the saturation temperature. At a certain temperature, when the gas dissolved in the water and the gas separated from the water are in a dynamic equilibrium state, the amount of gas dissolved in a unit volume of water is proportional to the partial pressure of the gas on the water surface. S5. Measure the static pressure and dynamic pressure inside the deaerator shell, the static pressure and dynamic pressure inside the steam storage tank, and the total pressure inside the intake pipe respectively through multiple pressure sensors. V1 = (2G / ρ)½, V2 = V1*S. V1 is the gas flow rate, G is the static pressure, ρ is the density of water vapor, and V2 is the volume change of water vapor. According to the dynamic pressure indication inside the deaerator shell, V1 can be obtained, and the cross-sectional area S of the pipeline when the gas flows out of the deaerator shell can be used to quickly calculate the volume V2 of the gas flowing out. The volume of the pumped-in gas is quickly adjusted through the air pump at the input end of the steam storage tank. S7. The other water vapor inlet of the deaerator, that is, the intake pipe, is supplied with gas in a manner of stabilizing the pressure by an air pump. The total pressure of the pressure sensor inside the intake pipe in S5 is used to indicate whether the steam intake end is stable. The static pressure inside the deaerator shell is the real-time pressure of water vapor. The oxygen content in the water in the water tank reaches the operating standard of 0 - 7 μg / L under high pressure and less than 15 μg / L under low pressure. When the feed water is heated at a constant pressure, as the evaporation process of the water proceeds, the amount of steam on the water surface continuously increases, and the partial pressure of the steam gradually rises. The gas is discharged in time, and the partial pressures of various gases on the water surface continuously decrease accordingly.

[0026] Embodiment 2:

[0027] The embodiment of the present invention provides a method for controlling the pressure of a deaerator, including the following steps:

[0028] S1. Before the deaerator runs, that is, before feeding water, high-pressure steam is introduced into the interior of the steam storage tank, and the steam storage tank and the outer shell of the deaerator are kept in a non-connected state. S2. Observe the gas pressure inside the steam storage tank. The outer surface of the steam storage tank is provided with a heat-insulating layer, and a heating device is arranged inside the steam storage tank to maintain the gas pressure inside the steam storage tank. When the gas pressure is twice the standard pressure for the operation of the deaerator, water vapor is introduced into the interior of the deaerator, and the inlet pipe is opened to introduce water vapor with a stable flow rate. S3. Open the valve at the water inlet, so that the condensate water and makeup water first enter the water chamber of the inner rotary film device group in the deaerator head, and under a certain water level differential pressure, spray obliquely from the small holes of the film tube into the inner hole to form a jet. The water level differential pressure is one atmospheric pressure. S4. Open the valve between the steam storage tank and the deaerator, and high-pressure gas quickly enters the interior of the deaerator shell, so that the pressure reaches the pressure required for the operation of the deaerator. The rising heating steam, and the water will suck in a large amount of heating steam during the jet movement. A strong mixing and heating effect is generated in a very short time and a very small stroke, and the water temperature is greatly increased. The rotating water continues to rotate downward along the inner wall of the film tube to form a rolling water film skirt. At this time, the heat transfer and mass transfer effect of the turbulent water is the best, and the water temperature reaches the saturation temperature. At a certain temperature, when the gas dissolved in the water and the gas separated from the water are in a dynamic equilibrium state, the amount of gas dissolved in the unit volume of water is proportional to the partial pressure of the gas on the water surface. S5. Measure respectively through multiple pressure sensors the static pressure and dynamic pressure inside the deaerator shell, the static pressure and dynamic pressure inside the steam storage tank, and the total pressure inside the intake pipe. V1 = (2G / ρ)½, V2 = V1*S. Where V1 is the gas flow rate, G is the static pressure, ρ is the density of water vapor, and V2 is the volume change of water vapor. According to the dynamic pressure indication inside the deaerator shell, V1 can be obtained, and the cross-sectional area S of the pipe when the gas flows out of the deaerator shell can be used to quickly calculate the volume V2 of the gas flowing out. The volume of the pumped gas is quickly adjusted through the air pump at the input end of the steam storage tank. S7. The other water vapor inlet of the deaerator, that is, the intake pipe, is supplied with gas in a manner of stabilizing the pressure by an air pump. The total pressure of the pressure sensor inside the intake pipe in S5 is used to display whether the steam intake end is stable. The static pressure inside the deaerator shell is the real-time pressure of water vapor. The oxygen content of the water in the water tank is 0 - 7 μg / L under high pressure and less than 15 μg / L under low pressure to meet the operation standard. When the feed water is heated at a constant pressure, as the evaporation process of the water progresses, the amount of steam on the water surface continuously increases, and the partial pressure of the steam gradually rises. The gas is discharged in time, and the partial pressures of various gases on the water surface continuously decrease accordingly.

[0029] Example Three:

[0030] The embodiment of the present invention provides a method for controlling the pressure of a deaerator, including the following steps:

[0031] S1. Before the operation of the deaerator, that is, before feeding water, high-pressure steam is introduced into the interior of the steam storage tank, and the state of non-connection is maintained between the steam storage tank and the outer shell of the deaerator. S2. Observe the gas pressure inside the steam storage tank. The outer surface of the steam storage tank is provided with a heat-insulating layer, and a heating device is arranged inside the steam storage tank to maintain the gas pressure inside the steam storage tank. When the gas pressure is 1.7 times the standard pressure for the operation of the deaerator, water vapor is introduced into the interior of the deaerator, and the inlet pipe is opened to introduce water vapor with a stable flow rate. S3. Open the valve at the water inlet, so that the condensate water and make-up water first enter the water chamber of the inner spiral film device in the deaerator head, and spray obliquely from the small holes of the film tube into the inner hole under a certain water level differential pressure to form a jet. The water level differential pressure is one atmospheric pressure. S4. Open the valve between the steam storage tank and the deaerator, and high-pressure gas quickly enters the interior of the deaerator shell, so that the pressure reaches the pressure required for the operation of the deaerator. The rising heating steam is sucked in a large amount by the water during the jet movement, and a strong mixing and heating effect is generated in a very short time and a very small stroke, and the water temperature is greatly increased. The rotating water continues to rotate downward along the inner wall of the film tube to form a rolling water film skirt. At this time, the heat transfer and mass transfer effect of the turbulent water is the best, and the water temperature reaches the saturation temperature. At a certain temperature, when the gas dissolved in the water is in dynamic equilibrium with the gas separated from the water, the amount of gas dissolved in the unit volume of water is proportional to the partial pressure of the gas on the water surface. S5. Measure respectively through multiple pressure sensors the static pressure and dynamic pressure inside the deaerator shell, the static pressure and dynamic pressure inside the steam storage tank, and the total pressure inside the intake pipe. V1 = (2G / ρ)½, V2 = V1 * S. V1 is the gas flow rate, G is the static pressure, ρ is the density of water vapor, and V2 is the volume change of water vapor. According to the dynamic pressure indication inside the deaerator shell, V1 is obtained, and the cross-sectional area S of the pipe when the gas flows out of the deaerator shell can be used to quickly calculate the volume V2 of the gas flowing out. The volume of the pumped-in gas is quickly adjusted through the air pump at the input end of the steam storage tank. S7. The other water vapor inlet of the deaerator, that is, the intake pipe, is supplied with gas in a manner of stabilizing the pressure by an air pump. The total pressure of the pressure sensor inside the intake pipe in S5 is used to indicate whether the steam inlet end is stable. The static pressure inside the deaerator shell is the real-time pressure of water vapor. The oxygen content in the water in the water tank reaches the operating standard of 0 - 7 μg / L under high pressure and less than 15 μg / L under low pressure. When the feed water is heated at a constant pressure, as the evaporation process of the water progresses, the amount of steam on the water surface continuously increases, the partial pressure of the steam gradually rises, and the gas is discharged in time, and the partial pressures of various gases on the water surface continuously decrease accordingly.

[0032] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A deaerator pressure control method, characterized in that: It includes the following steps: S1. Before the deaerator runs, that is, before feeding water, high-pressure steam is introduced into the interior of the steam storage tank, and the steam storage tank and the outer shell of the deaerator are kept in a non-connected state; S2. Observe the gas pressure inside the steam storage tank. When the gas pressure is 1.4 - 2 times the standard pressure for the operation of the deaerator, water vapor is introduced into the interior of the deaerator, and the inlet pipe is opened to introduce water vapor with a stable flow rate; S3. Open the valve at the water inlet, so that the condensate water and make-up water first enter the water chamber of the inner rotary film device group in the deaerator head, and under a certain water level differential pressure, spray obliquely inward from the small holes of the film tube into the inner hole to form a jet, and the water level differential pressure is one atmospheric pressure; S4. Open the valve between the steam storage tank and the deaerator, and high-pressure gas quickly enters the interior of the deaerator shell to make the pressure reach the pressure required for the operation of the deaerator; S5. Measure the static pressure and dynamic pressure inside the deaerator shell, the static pressure and dynamic pressure inside the steam storage tank, and the total pressure inside the intake pipe through multiple pressure sensors respectively; S6. According to the dynamic pressure indication inside the deaerator shell, obtain V1, and quickly calculate the volume V2 of the gas flowing out through the cross-sectional area S of the pipe when the gas flows out of the deaerator shell, and quickly adjust the volume of the pumped-in gas through the air pump at the input end of the steam storage tank; S7. For another water vapor inlet of the deaerator, that is, the intake pipe, it is carried out by the method of supplying gas with a stable pressure by an air pump.

2. The deaerator pressure control method according to claim 1, wherein: The outer surface of the steam storage tank is provided with a heat insulation layer, and a heating device is arranged inside the steam storage tank.

3. A deaerator pressure control method according to claim 1, characterized in that: For the heating steam rising in S4, a large amount of heating steam is sucked in by the water during the jet movement, and a strong mixing and heating effect is generated in a very short time and a very small stroke, the water temperature is greatly increased, and the rotating water continues to rotate downward along the inner wall of the film tube to form a rolling water film skirt. At this time, the heat transfer and mass transfer effect of the turbulent water is the best, and the water temperature reaches the saturation temperature.

4. A deaerator pressure control method according to claim 1, characterized in that: V1=(2G / ρ)½, V2=V1*S, where V1 is the gas flow rate, G is the static pressure, ρ is the density of water vapor, and V2 is the changed volume of water vapor.

5. A deaerator pressure control method according to claim 1, characterized in that: In S5, the total pressure of the pressure sensor inside the intake pipe is used to indicate whether the steam inlet end is stable, and the static pressure inside the deaerator shell is the real-time pressure of water vapor.