JP3242218U - Device for reducing the amount of dissolved oxygen in condensed water - Google Patents

Abstract

A device for reducing the amount of dissolved oxygen in condensed water is provided. A device for reducing the amount of dissolved oxygen in condensed water includes a vacuum deoxygenator provided with a steam supply pipe, a high-temperature and high-pressure extraction unit communicating with the steam supply pipe of the vacuum deoxygenator, and the vacuum deoxygenator. and a hotwell communicating with. To improve the steam supply pressure and temperature of the vacuum deoxygenator by the high temperature and high pressure extraction unit, further improve the deoxygenation effect of the vacuum deoxygenator on the condensed water, and effectively reduce the dissolved oxygen content in the condensed water. As a result, the condensed water with dissolved oxygen content within the standard enters the heat exchange system and the attached pipes of the heat exchange system, and the galvanic effect does not appear, causing electrochemical corrosion of the metal members inside the pipes. avoid doing. It also reduces the heat exchange thermal resistance of the steam turbine heat recovery system and improves the heat recovery efficiency. It also improves the vacuum degree of the condenser, ensures the safe operation of the equipment, and improves the economic efficiency and load capacity of the air cooling unit. [Selection drawing] Fig. 1

Description

TECHNICAL FIELD The present invention relates to the technical field of air cooling units, and more particularly to a device for reducing dissolved oxygen content in condensed water.

With the increasing capacity of thermal power generation units in recent years, the requirements for the water quality of condensed water have increased, and the dissolved oxygen content in condensed water is an important indicator for chemical monitoring. According to the regulations of << steam quality of thermal power generation units and steam power facilities >> (GB/T12145-2018), the expected value of dissolved oxygen in the condensed water of 3000 MW thermal power generation units reaches 30 ug / L, and during normal operation of the unit In most cases, the dissolved oxygen in the condensed water can meet the standard requirements, ideally there is no air and the degree of subcooling is zero, the solubility of oxygen in the liquid approaches zero. Therefore, the condenser is designed to specifications similar to the deoxygenator and is optimally effective at full load operation.

The working principle of the vacuum deoxygenator is to apply Henry's law and Dalton's law. According to Henry's law, in a closed container, if any gas exists on the surface of the water at the same time, the solubility of the gas is is directly proportional to its own partial pressure, and the solubility of a gas is known to be related only to its own partial pressure. Vacuum deoxygenator reduces the partial pressure of the water surface at a constant negative pressure, the partial pressure of air and oxygen becomes smaller and smaller, the partial pressure of oxygen drops to zero, and the dissolved oxygen in water also drops to zero . If the pressure on the surface of the water is less than atmospheric pressure, the solubility of oxygen can become zero at low water temperatures. In this way, the oxygen molecules in the space above the water surface are drawn out or converted to other gases, so that the partial pressure of oxygen becomes zero, and the oxygen in the water is continuously drawn out, resulting in a scavenging effect. Achieve.

However, it is likely that the dissolved oxygen content in the condensed water is high due to deterioration of the equipment, abnormal water supply, leakage of the equipment, and the like. After the condensed water with dissolved oxygen exceeding the standard enters the heat exchange system and the auxiliary pipes of the heat exchange system, the galvanic effect appears, causing electrochemical corrosion of the metal members inside the pipes. In addition, the surface of the heat exchanger of the steam turbine heat recovery system will form a film on the surface of the heat exchanger due to the agglomerated corrosives, increasing the thermal resistance of the heat exchange and reducing the heat recovery efficiency. Also, high dissolved oxygen content in the condensate can cause excess air to leak into the condenser, reducing vacuum, adversely affecting the unit's economics and, in severe cases, reducing the unit's power output. This means increasing the bleed load on the bleed system and resulting in energy loss.

Therefore, how to effectively reduce the dissolved oxygen content in the condensed water is a technical problem to be solved urgently by those skilled in the art.

To solve the problem of high dissolved oxygen content in condensed water, the present invention provides a device for reducing dissolved oxygen content in condensed water.

The apparatus for reducing the dissolved oxygen content in condensed water provided to achieve the object of the present invention is
a vacuum deoxygenator provided with a steam supply pipe;
a high temperature and high pressure extraction unit communicating with the steam supply pipe of the vacuum deoxygenator;
a hotwell in communication with the vacuum deoxygenator.

In some specific embodiments, the high temperature, high pressure bleed unit is a seventh stage bleed line located inside the condenser.

In some specific embodiments, the apparatus for reducing the amount of dissolved oxygen in condensate comprises:
It further includes a first shut-off valve with both ends communicating with the high temperature and high pressure bleed unit and the vacuum deoxygenator, respectively.

In some specific embodiments, the apparatus for reducing the amount of dissolved oxygen in condensate comprises:
It further includes a second isolation valve with each end communicating with the hotwell and the vacuum deoxygenator.

In some specific examples, the first isolation valve is a manual isolation valve.

In some specific examples, the line communicating between the high temperature high pressure bleed unit and the vacuum deoxygenator is 304 stainless steel seamless pipe.

In some specific embodiments, the diameter of the conduit communicating between the high temperature, high pressure extraction unit and the vacuum deoxygenator is between 210 mm and 220 mm.

In some specific embodiments, the vacuum deoxygenator is a deoxygenated water tank at the bottom and a deoxygenation tower at the top,
A steam feed line is provided to the deoxygenation tower.

Beneficial effects of the present invention are as follows. The apparatus for reducing the amount of dissolved oxygen in condensed water according to the present invention uses a high-temperature, high-pressure extraction unit to improve the steam supply pressure and temperature of the vacuum deoxygenator, and further to improve the deoxygenation effect of the vacuum deoxygenator on the condensed water. , effectively reducing the dissolved oxygen content in the condensed water, so that the dissolved oxygen content in the condensed water reaches the standard. After the condensed water with dissolved oxygen reaches the standard enters the heat exchange system and the auxiliary pipe of the heat exchange system, the galvanic effect does not appear, avoiding the electrochemical corrosion of the metal members inside the pipe. . In addition, the surface of the heat exchanger of the steam turbine heat recovery system does not form a film on the surface of the heat exchanger due to agglomerated corrosives, which reduces the heat exchange thermal resistance and improves the heat recovery efficiency. It also improves the vacuum degree of the condenser, ensures the safe operation of the equipment, and improves the economic efficiency and load capacity of the air cooling unit.

1 is a schematic configuration diagram of one specific embodiment of a device for reducing the amount of dissolved oxygen in condensed water according to the present invention; FIG. FIG. 2 is a schematic configuration diagram of some specific examples of a vacuum deoxygenator in the apparatus for reducing the amount of dissolved oxygen in condensed water shown in FIG. 1;

The following clearly and completely describes the technical means in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Apparently, the described embodiments are only part of the present invention, not all of them.

Examples of the above embodiments are shown in the drawings, throughout which the same or similar reference numerals indicate the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the drawings are merely illustrative and are for the purpose of interpreting the present invention, and should not be understood as limiting the present invention.

In the description of the present invention, terms such as "top", "bottom", "inside", "outside", "axial direction", and "circumferential direction" refer to directions or positional relationships shown in the drawings. Based on relationships and merely for the purpose of conveniently or simply describing the present invention, it is assumed that any device or component shown necessarily has a particular orientation and is configured and operated in a particular orientation. It is not intended to be an indication or to be implied and should not be construed as a limitation on the invention.

In addition, the terms "first" and "second" are only for describing purposes, and either indicate or imply relative importance or imply the number of technical features shown. It should not be understood as instructing. As such, a feature that is qualified as "first" and "second" expressly or implicitly includes one or more of such features. In the description of the present invention, the term "plurality" means two or more, unless expressly specified otherwise.

In the present invention, the meanings of terms such as "attachment", "connection", "connection", "fixation", "engagement", and "hinged connection" should be broadly understood unless explicitly defined and limited. be. For example, it may be a fixed connection, a removable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, or an indirect connection via an intermediate medium. There may also be communication between the two parts or an interaction relationship between the two parts. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to the specific situation.

As described in the Background Art, a situation in which the dissolved oxygen content in the condensed water is high is likely to occur due to deterioration of the equipment, abnormality of the water supply, leakage of the equipment, and the like.

In order to improve the above problems, the present application includes a vacuum deoxygenator 110, a high temperature and high pressure extraction unit 120, a hot well 130, a first isolation valve 140 and a second isolation valve 150, as shown in FIGS. Provided is a device for reducing the amount of dissolved oxygen in condensed water. The vacuum deoxygenator 110 is provided with a steam supply pipe 1121 . The high temperature and high pressure extraction unit 120 communicates with the steam supply pipe 1121 of the vacuum deoxygenator 110 . Hotwell 130 communicates with vacuum deoxygenator 110 . Both ends of the first shutoff valve 140 communicate with the high temperature and high pressure extraction unit 120 and the vacuum deoxygenator 110, respectively. Both ends of the second shutoff valve 150 communicate with the hot well 130 and the vacuum deoxygenator 110, respectively. They are shut off by the first shutoff valve 140 and the second shutoff valve 150 respectively. The high temperature and high pressure extraction unit 120 can improve the steam supply pressure and temperature of the vacuum deoxygenator 110, further improve the deoxygenation effect of the vacuum deoxygenator 110 on the condensed water, and effectively reduce the dissolved oxygen content in the condensed water. By lowering the dissolved oxygen content in the condensate reaches the norm. After the condensed water with dissolved oxygen reaches the standard enters the heat exchange system and the auxiliary pipe of the heat exchange system, the galvanic effect does not appear, avoiding the electrochemical corrosion of the metal members inside the pipe. . In addition, the surface of the heat exchanger of the steam turbine heat recovery system does not form a film on the surface of the heat exchanger due to agglomerated corrosives, which reduces the thermal resistance of heat exchange and improves heat recovery efficiency. It also improves the vacuum degree of the condenser, ensures the safe operation of the equipment, and improves the economic efficiency and load capacity of the air cooling unit.

Preferably, in the illustrative example, the high temperature, high pressure bleed unit 120 is a seventh stage bleed line provided inside the condenser. Utilizing the high bleed pressure and high temperature of the 7th bleed line provided inside the condenser, the steam supply pressure and temperature of the vacuum deoxygenator 110 can be improved at a lower cost, Furthermore, by improving the deoxidizing effect of the vacuum deoxygenator 110 on the condensed water and effectively reducing the dissolved oxygen content in the condensed water, the dissolved oxygen content in the condensed water reaches the standard. Ensure the safe operation of the equipment, improve the economic efficiency and load capacity of the air cooling unit. Under normal operating conditions, the replenished demineralized water can pass through the vacuum deoxygenator 110 so that the dissolved oxygen content reaches the standard.

Preferably, in the illustrative example, first isolation valve 140 is a manual isolation valve. The operator has direct control over the opening and closing of the manual isolation valve.

Preferably, in the illustrative example, the line communicating between the high temperature, high pressure extraction unit 120 and the vacuum deoxygenator 110 is 304 stainless steel seamless pipe. 304 stainless steel seamless pipe is a steel pipe that is resistant to corrosion in mildly corrosive media such as air, steam, water, and chemically aggressive media such as acids, alkalis, and salts.

Preferably, in the illustrative example, the diameter of the conduit communicating between the high temperature, high pressure extraction unit 120 and the vacuum deoxygenator 110 is between 210 mm and 220 mm. Specifically, the diameter of the conduit connecting the high-temperature, high-pressure extraction unit 120 and the vacuum deoxygenator 110 is 210 mm, 215 mm, 219 mm, or 220 mm.

Preferably, in the illustrative example, the vacuum deoxygenator 110 has a deoxygenated water tank 111 at the bottom and a deoxygenation tower 112 at the top. The internal structures of the deoxygenated water tank 111 and the deoxygenated tower 112 are conventional technology, and the description thereof is omitted here. A steam supply pipe 1121 is provided in the deoxygenation tower 112 .

In the description of this specification, terms such as "one embodiment", "some embodiments", "example", "specific example", "one specific embodiment" or "some examples" is meant to include in at least one embodiment or example of the invention the specific feature, structure, material or property described in combination with that embodiment or example. Schematic representations of terms in this specification do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described may be combined as appropriate in any one or more embodiments or examples.

The above are only preferred and specific embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent replacement or modification made according to the idea of the present invention shall fall within the protection scope of the present invention.

110 vacuum deoxygenator 111 deoxygenated water tank 112 deoxygenation tower 1121 steam supply pipe 120 high temperature and high pressure extraction unit 130 hot well 140 first shutoff valve 150 second shutoff valve

Claims (8)

a vacuum deoxygenator provided with a steam supply pipe;
a high temperature and high pressure extraction unit communicating with the steam supply pipe of the vacuum deoxygenator;
a hotwell in communication with the vacuum deoxygenator;
A device for reducing the amount of dissolved oxygen in condensed water, characterized by: The high-temperature and high-pressure extraction unit is a seventh-stage extraction pipe provided inside the condenser,
The apparatus for reducing the amount of dissolved oxygen in condensed water according to claim 1, characterized in that: further comprising a first isolation valve having both ends respectively communicating with said high temperature and high pressure bleed unit and said vacuum deoxygenator;
The apparatus for reducing the amount of dissolved oxygen in condensed water according to claim 1, characterized in that: further comprising a second isolation valve having opposite ends communicating with the hotwell and the vacuum deoxygenator, respectively;
The apparatus for reducing the amount of dissolved oxygen in condensed water according to claim 3, characterized in that: wherein the first shutoff valve is a manual shutoff valve;
The apparatus for reducing the amount of dissolved oxygen in condensed water according to claim 3, characterized in that: The pipeline communicating between the high temperature and high pressure extraction unit and the vacuum deoxygenator is a 304 stainless steel seamless pipe.
The apparatus for reducing the amount of dissolved oxygen in condensed water according to any one of claims 1 to 5, characterized in that: The diameter of the conduit connecting the high-temperature high-pressure extraction unit and the vacuum deoxygenator is 210 mm to 220 mm.
The apparatus for reducing the amount of dissolved oxygen in condensed water according to any one of claims 1 to 5, characterized in that: The vacuum deoxygenator has a deoxygenated water tank at the bottom and a deoxygenation tower at the top,
A steam supply pipe is provided in the deoxygenation tower,
The apparatus for reducing the amount of dissolved oxygen in condensed water according to any one of claims 1 to 5, characterized in that:

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