KR102740289B1 - System and method for providing steam by using combined heat and power - Google Patents

Abstract

A steam supply system and method using combined heat and power generation are disclosed. According to a preferred embodiment of the present invention, a steam supply system is provided, which includes a flash tank for generating steam by reducing hot water supplied from a combined heat and power generation to a pressure lower than the supply pressure of the hot water, and an evaporator for receiving the steam generated in the flash tank and generating steam at a higher pressure and temperature than the steam generated in the flash tank required by a demander.
According to the present invention, steam can be produced and supplied by utilizing combined heat and power generation that produces both electricity and heat, and by utilizing already implemented combined heat and power generation, there is an advantage in that the cost of steam production is reduced and the installation and operation of equipment for steam production are also easy.

Description

{System and method for providing steam by using combined heat and power}

The present invention relates to a steam supply system and method, and more particularly, to a steam supply system and method using combined heat and power generation.

Combined heat and power (CHP) is a form of power generation that simultaneously produces electricity and supplies heat to increase the overall energy utilization rate. It is called combined heat and power and is abbreviated as CHP.

In other words, combined heat and power generation uses turbines or engines to produce electricity and hot water or steam that can be used as a heat source for heating or industrial processes.

However, depending on the type or capacity of the combined heat and power generator, it often only produces hot water and has limitations in steam production.

Meanwhile, not only hot water but also vaporized water, steam, is used for various purposes, and in particular, various industrial fields require this steam in various forms.

Although they have the same meaning in the dictionary, steam that is generally used for industrial purposes is called steam to distinguish it separately. In the following, the terms steam and vapor are used interchangeably, but ultimately, the steam used in the industrial field is called steam, but it is not limited to this.

Meanwhile, steam is used in a variety of ways in the industrial field, especially in factories, where steam itself is used as a power source to drive equipment, and steam is used in various ways as a heat source.

For this reason, factories that require steam generally install separate equipment such as boilers to separately produce and use steam, but there is a problem that the cost of producing steam is high.

In addition, if facilities are installed to produce electricity and steam together to operate the equipment required in the factory, the cost increases significantly, and in particular, there is a problem of a large financial burden because a lot of electricity and raw materials are consumed to produce steam.

In order to solve the conventional problems as described above, the present invention proposes a steam supply system and method that can produce and supply steam by using combined heat and power generation that produces both electricity and heat.

And, by utilizing the already implemented combined heat and power generation, the cost of steam production is reduced and a steam supply system and method that make installation and operation of facilities for steam production easy are proposed.

Other objects of the present invention will be readily understood through the description of the following embodiments.

In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a steam supply system using combined heat and power generation is provided.

According to a preferred embodiment of the present invention, a steam supply system using combined heat and power generation is provided, characterized in that it includes: a flash tank which generates steam by reducing hot water supplied from the combined heat and power generation to a pressure lower than the supply pressure of the hot water; and an evaporator which receives the steam generated in the flash tank and generates steam at a pressure and temperature required by a demander, wherein the steam generated in the evaporator is generated at a higher pressure and temperature than the steam generated in the flash tank.

The above flash tank can recover condensate generated from the production and use of steam generated in the above evaporator and supply the recovered condensate as cooling water for the combined heat and power generation.

And the steam supply system further includes a condensate tank for recovering condensate generated by the production and use of steam generated in the evaporator, and the condensate tank is connected to the flash tank so as to provide the condensate to the flash tank.

Additionally, the condensate tank can provide the condensate to the flash tank when there is no supply of hot water from the combined heat and power generation unit.

And the above condensate tank can provide steam included in the recovery process of condensate generated by the generation and use of steam generated in the above evaporator to the above steam supply unit.

The above evaporator can be at least one of MVR (Mechanical Vapor Recompression) and TVR (Thermal Vapor Recompression).

The above evaporator is included in a steam supply unit that supplies steam to a demand source, and the steam supply unit may include at least one of an evaporator, a mechanical vapor recompression (MVR), and a thermal vapor recompression (TVR).

According to another aspect of the present invention, a method for supplying steam using combined heat and power generation is provided.

According to a preferred embodiment of the present invention, a method for supplying steam in a steam supply system using a combined heat and power generation unit, which includes a combined heat and power generation unit, a flash tank, and an evaporator, is provided, comprising: a step of introducing hot water supplied from the combined heat and power generation unit into the flash tank having a pressure lower than a supply pressure of the hot water and evaporating the hot water into steam; a step of supplying the evaporated steam to the evaporator to generate steam having a pressure and temperature required by a demander, wherein the steam generated in the evaporator is generated at a higher pressure and temperature than the steam generated in the flash tank; and a step of supplying the generated steam to the demander.

The above flash tank can recover condensate generated from the production and use of steam generated in the above evaporator and supply the recovered condensate as cooling water for the combined heat and power generation.

And the steam supply system further includes a condensate tank for recovering condensate generated by the generation and use of steam generated in the evaporator, and the condensate tank is connected to the flash tank, so that in the steam supply method, the condensate can be provided to the flash tank.

Additionally, in the above steam supply method, the condensate tank can be configured to provide the condensate to the flash tank when there is no supply of hot water from the combined heat and power generation unit.

And in the above steam supply method, the condensate tank can provide steam included in the recovery process of condensate generated by the generation and use of steam generated in the evaporator to the steam supply unit.

In the above steam supply system, the evaporator may be at least one of MVR (Mechanical Vapor Recompression) and TVR (Thermal Vapor Recompression).

In the above steam supply system, the evaporator is included in a steam supply unit that supplies steam to a demand source, and the steam supply unit may include at least one of an evaporator, MVR (Mechanical Vapor Recompression), and TVR (Thermal Vapor Recompression).

As described above, the steam supply system and method using combined heat and power generation according to the present invention has the advantage of being able to produce and supply steam using combined heat and power generation that produces both electricity and heat.

In addition, by utilizing the already implemented combined heat and power generation, there is the advantage of reducing the cost of steam production and making it easy to install and operate facilities for steam production.

Figure 1 is a drawing showing the configuration of a steam supply system according to a preferred embodiment of the present invention.
FIG. 2 is a drawing showing the configuration of a steam supply system according to another preferred embodiment of the present invention.
FIG. 3 is a flowchart illustrating the sequence in which a steam supply method according to a preferred embodiment of the present invention is implemented.

The present invention can have various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

In describing each drawing, similar reference numerals are used for similar components. In describing the present invention, if it is judged that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description is omitted.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another.

For example, without departing from the scope of the present invention, the first component could be named the second component, and similarly, the second component could also be named the first component.

The term and/or includes any combination of multiple related described items or any one of multiple related described items.

When it is said that a component is "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but there may also be other components present in between.

On the other hand, when it is said that a component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

The terminology used in this application is used only to describe particular embodiments and is not intended to limit the present invention.

Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly defined in this application.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Regardless of the drawing symbols, identical or corresponding components are given the same reference numerals and redundant descriptions thereof will be omitted.

First, referring to Fig. 1, let us examine the configuration of a steam supply system according to a preferred embodiment of the present invention.

FIG. 1 is a drawing illustrating the configuration of a steam supply system according to a preferred embodiment of the present invention.

As illustrated in FIG. 1, a steam supply system according to a preferred embodiment of the present invention includes a combined heat and power generation unit (100), a flash tank (110), and a steam supply unit (120).

The combined heat and power generation unit (100) is a power generation unit that simultaneously produces electricity and supplies heat, and may be a conventional combined heat and power plant.

And it is obvious that not only the combined heat and power plant that is already installed and in operation, but also the combined heat and power generation unit (100) according to the present invention can correspond to the combined heat and power generation unit if it is a form of combined heat and power generation that provides hot water and electricity together.

That is, the combined heat and power generation unit (100) of the present invention can correspond to the combined heat and power generation unit (100) of the present invention in any case where electricity production and heat, particularly hot water supply, are performed simultaneously.

In the present invention, high temperature and high pressure hot water provided from a combined heat and power generation unit (100), i.e. a combined heat and power plant, is supplied to a flash tank (110).

Meanwhile, hot water supplied from the combined heat and power generation unit (100) is provided as high temperature and high pressure hot water for smooth hot water supply, but there is a problem in that it is difficult to generate it directly as industrial steam, i.e. steam.

In addition, since the temperature and pressure of the steam desired by each demand source, such as a factory that actually uses steam, are all different and the demand time for steam is also different, it is difficult to immediately generate hot water supplied from the combined heat and power generation unit (100) into steam and use it.

To solve these problems, the present invention reduces the pressure of hot water supplied from a combined heat and power generation unit (100) and generates it as steam.

Since the steam generated in this way is not used directly for industrial purposes, it is called vapor rather than steam.

That is, the flash tank (110) first generates steam by reducing the hot water supplied from the combined heat and power generation unit (100) to a pressure lower than the supply pressure of the supplied hot water.

Meanwhile, when drain and boiler water under high pressure are released to a place lower than that pressure, some of the drain evaporates again and becomes saturated drain of flash vapor, which is called the flash phenomenon.

A flash tank (110) is inserted between the high-pressure steam return pipe and the low-pressure steam return pipe in steam heating to reduce the return pressure and produce low-pressure steam, and is also used as a device to recover heat loss.

In the present invention, a flash tank, which is a tank utilizing the flash phenomenon, is used to induce high temperature/high pressure hot water into a low pressure flash tank to evaporate it.

Meanwhile, in general, when producing steam in stages, such as primary steam generation and industrial steam production, the thermal efficiency may be relatively lower compared to producing steam directly from hot water.

However, in order to solve these problems, the present invention maximizes heat efficiency by minimizing heat loss through the use of a flash tank, and also produces secondary steam that meets the demand by producing primary steam before producing steam, which is industrial steam.

In particular, since the latent heat required to convert hot water into steam is very large using only the sensible heat of hot water, it is impossible to convert all hot water into steam. Therefore, using only the sensible heat of hot water to produce only a portion of the hot water into steam and then converting the steam produced at this time into high-temperature, high-pressure steam results in higher energy efficiency. In order to take advantage of this, the present invention utilizes a flash tank (110).

Meanwhile, various studies and developments are being conducted on these flash tanks (110) to further maximize thermal efficiency, and in the present invention, there is no limitation on any flash tank that can increase thermal efficiency and produce steam by utilizing the flash phenomenon.

The steam generated in the flash tank (110) is generated as steam, which is industrial steam, in an evaporator (not shown) included in the steam supply unit (120). The steam generated at this time is steam with a higher pressure and temperature than the steam generated in the flash tank (110) required by the demander, and is used for industrial purposes only, so it is referred to as steam.

Meanwhile, in FIG. 1, a component that produces steam and supplies it to a demand source is depicted as a steam supply unit (120). It is self-evident that this steam supply unit (120) may be configured with an evaporator that produces steam, a pipe and valve that supplies steam to a demand source, a control unit, etc., but for convenience of explanation, the present invention will be described focusing on the evaporator, which is the most important component of the steam supply unit (120).

As mentioned above, the reason why relatively low-temperature/low-pressure primary steam is generated in the flash tank (110) and high-temperature/high-pressure steam is generated in the evaporator is that hot water supplied from the combined heat and power generation unit (100) is provided as high-temperature and high-pressure hot water for smooth hot water supply, but it is difficult to generate this as industrial steam, i.e. steam, and the temperature and pressure of the steam desired by the demanders, such as factories that actually use the steam, are all different.

To solve these problems, the present invention uses both a flash tank (110) and an evaporator to provide steam at the temperature and pressure required by the user, and also to increase thermal efficiency.

Meanwhile, in the case of evaporators that produce steam required by the demand source, it is possible to use MVR (Mechanical Vapor Recompression) or TVR (Thermal Vapor Recompression) to increase thermal efficiency.

In general, MVR and TVR refer to evaporators or methods that recover heat generated from waste steam to increase thermal efficiency. Rather than being used alone, they are used together with other evaporators to reuse heat from waste steam in other evaporators through heat exchange or other methods to increase thermal efficiency.

In the present invention, it is possible to use the MVR or TVR alone to produce the desired steam directly at the point of demand, or to use it together with another evaporator as in the past to further increase the thermal efficiency.

Meanwhile, the flash tank (110) recovers condensate generated from the production and use of steam generated in the evaporator and re-supplies the recovered condensate as cooling water for the combined heat and power generation.

During the process of generating and using steam, a condensation phenomenon occurs in which gas changes into liquid. The condensate that occurs at this time is recovered back into the flash tank (110) and supplied again as cooling water to the combined heat and power generation unit (100).

And, the condensate may be recovered to the flash tank (110) and used to maintain the low temperature/low pressure of the flash tank (110) at a relatively low temperature/low pressure compared to the high temperature/high pressure hot water supplied from the combined heat and power generation unit (100).

Meanwhile, due to the nature of combined heat and power generation, the use of hot water is limited in seasons such as summer, so the supply of hot water from the combined heat and power generation unit (100) may be limited.

In addition, there may be cases where hot water is not supplied from the combined heat and power generation unit (100) due to reasons such as a breakdown or maintenance of the combined heat and power generation unit, and in such cases, it becomes difficult to produce steam any longer.

In preparation for such cases, it will be possible to prepare for interruption of hot water supply from the combined heat and power generation unit (100) by storing condensate in a separate condensate tank and controlling and utilizing it.

Figure 2 illustrates an example of the configuration of the present invention when a separate condensate tank (130) is included to prepare for a disruption in the supply of hot water from a combined heat and power generation unit (100).

FIG. 2 is a drawing illustrating the configuration of a steam supply system according to another preferred embodiment of the present invention.

As illustrated in FIG. 2, the configuration of a steam supply system according to another preferred embodiment of the present invention further includes a condensate tank (130).

The condensate tank (130) is connected to the flash tank (110) and the steam supply unit (120), and the condensate generated by the production and use of steam generated in the steam supply unit (120) is first recovered to the condensate tank (130).

And the condensate tank (130) stores condensate and can provide condensate to the flash tank (110) when necessary, for example, when the supply of hot water from the combined heat and power generation unit (100) is interrupted or when more condensate is needed as cooling water in the combined heat and power generation unit (100).

In addition, by selectively providing condensate from the condensate tank (130) to the flash tank (110) when necessary for controlling temperature or pressure for generating primary steam in the flash tank (110), steam can be stably provided to the demand source even under various conditions and environments, and cooling water required for combined heat and power generation can also be provided to the combined heat and power generation unit (100) as needed.

And in the process of recovering the condensate generated from the generation and use of steam generated in the steam supply unit (120), not only the condensate but also some steam is recovered. At this time, the recovered steam can be provided back to the steam supply unit (120) and used to produce steam.

In addition, in cases where the operation of the combined heat and power generation is stopped, when the cooling water of the combined heat and power generation needs to be replenished due to a shortage, or when the temperature or pressure of the flash tank needs to be adjusted, the steam supply system according to the present invention can be operated more stably by additionally including a condensate tank.

That is, the steam supply system utilizing combined heat and power generation according to the present invention can be operated more stably than when a separate condensate tank is included rather than directly supplying condensate to the flash tank, including only the flash tank.

Below, with reference to Fig. 3, we will once again examine the order in which the steam supply method is implemented in a steam supply system using a combined heat and power generation system having such a configuration.

FIG. 3 is a flowchart illustrating the sequence in which a steam supply method according to a preferred embodiment of the present invention is implemented.

As illustrated in FIG. 3, the sequence in which a steam supply method according to a preferred embodiment of the present invention is implemented is as follows: First, a process of generating steam by reducing the pressure of high-temperature and high-pressure hot water of a combined heat and power generation unit (100) in a flash tank (110) is performed (S200).

The hot water supplied from the combined heat and power generation unit (100) is provided as high temperature and high pressure hot water for smooth supply of hot water, but it is difficult to generate it directly as industrial steam, i.e. steam, and the temperature and pressure of the steam desired by the demanders, such as factories that actually use the steam, are all different, and the demand time for the steam is also different, so the hot water supplied from the combined heat and power generation unit (100) is not generated directly as industrial steam, i.e. steam.

In addition, since the latent heat required to convert hot water into steam is very large using only the sensible heat of hot water, it is impossible to convert all of the hot water into steam. Therefore, using only the sensible heat of the hot water to produce only a portion of the hot water into steam and then converting the steam produced at this time into high-temperature, high-pressure steam results in higher energy efficiency. Therefore, the present invention uses a flash tank (110) to take advantage of this point.

In this way, steam generated in the flash tank (110) is used to generate high temperature and high pressure steam desired by the demander in the evaporator (120) included in the steam supply unit (S202).

In the case of the evaporator (120), in order to offset the decrease in thermal efficiency caused by not directly generating the hot water supplied from the combined heat and power generation unit (100) into steam for industrial use, an MVR or TVR with increased thermal efficiency can be configured alone or together as described above.

And the condensate generated from steam generation and use is recovered in a flash tank (110) and provided to the combined heat and power generation unit (100) (S204).

Meanwhile, as described above, the condensate generated from steam generation and use is not configured to be directly recovered to the flash tank (110), but rather, it is possible to first recover the condensate tank (130) by including a separate condensate tank (130), so that it can be used for interrupting hot water supply in the combined heat and power generation unit (100) or controlling pressure and temperature in the flash tank (110).

In addition, as described above, in cases where cooling water is required in the combined heat and power generation unit (100), it is also possible to provide the condensate stored in the condensate tank (130) to the combined heat and power generation unit (100).

According to the steam supply system and method using combined heat and power generation according to the present invention, steam can be produced and supplied using combined heat and power generation that produces both electricity and heat, and by using the already implemented combined heat and power generation, the cost of steam production is reduced and the installation and operation of equipment for steam production are also simplified.

And the decrease in thermal efficiency, such as heat loss that may occur when hot water is not directly produced as steam but rather steam is produced in two stages, can be sufficiently offset by using MVR or TVR with increased thermal efficiency in the flash tank and evaporator.

In addition, if a separate condensate tank is included, steam can be produced regardless of the season or breakdown or maintenance of the combined heat and power plant, and the condensate generated during the production and use of steam can also be used as cooling water for the combined heat and power plant, resulting in high energy efficiency overall.

The above preferred embodiments of the present invention have been disclosed for the purpose of illustration, and those skilled in the art with common knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

Claims (14)

In a steam supply system using combined heat and power generation,
A flash tank for generating steam by reducing the hot water supplied from the above combined heat and power generation to a pressure lower than the supply pressure of the hot water; and
An evaporator that receives steam generated from the flash tank and generates steam at a pressure and temperature required by a demand source, wherein the steam generated from the evaporator is generated at a higher pressure and temperature than the steam generated from the flash tank;
The above evaporator is included in a steam supply section that supplies steam to the demand location,
The above flash tank recovers the condensate generated from the generation and use of steam generated in the above evaporator and supplies the recovered condensate as cooling water for the combined heat and power generation.
The above steam supply system further includes a condensate tank for recovering condensate generated from the generation and use of steam generated in the above evaporator,
The above condensate tank is connected to the above flash tank and supplies the condensate to the above flash tank,
The above condensate tank provides the condensate to the flash tank in the event that there is no supply of hot water from the combined heat and power generation plant,
A steam supply system characterized in that the above condensate tank supplies steam included in the process of recovering condensate generated by the generation and use of steam generated in the above evaporator back to the above steam supply unit.
delete delete delete delete In the first paragraph,
A steam supply system, wherein the evaporator is at least one of MVR (Mechanical Vapor Recompression) and TVR (Thermal Vapor Recompression).
delete A method for supplying steam in a steam supply system using cogeneration including a cogeneration unit, a flash tank and an evaporator,
A step of evaporating hot water supplied from the combined heat and power generation unit into the flash tank having a pressure lower than the supply pressure of the hot water and evaporating the hot water into steam;
A step of supplying the evaporated steam to the evaporator to generate steam at a pressure and temperature required by the demand source, wherein the steam generated in the evaporator is generated at a higher pressure and temperature than the steam generated in the flash tank; and
Including a step of supplying the generated steam to the above demand source,
In the above steam supply system, the evaporator is included in a steam supply section that supplies steam to a demand source,
The above flash tank recovers the condensate generated from the generation and use of steam generated in the above evaporator and supplies the recovered condensate as cooling water for the combined heat and power generation.
The above steam supply system further includes a condensate tank in which condensate generated by the generation and use of steam generated in the evaporator is recovered,
The above condensate tank is connected to the flash tank, and in the above steam supply method, the condensate is provided to the flash tank,
In the above steam supply method, the condensate tank provides the condensate to the flash tank when there is no supply of hot water from the combined heat and power generation,
A steam supply method characterized in that the above condensate tank supplies steam included in the process of recovering condensate generated by the generation and use of steam generated in the above evaporator to the above steam supply unit.
delete delete delete delete In Article 8,
A steam supply method, characterized in that the evaporator in the above steam supply system is at least one of MVR (Mechanical Vapor Recompression) and TVR (Thermal Vapor Recompression).
delete