阅读说明：本技术 一种中间汽水分离的直流蒸汽发生的系统和方法 (Intermediate steam-water separation direct-current steam generation system and method ) 是由 马晓珑 韩传高 刘俊峰 张瑞祥 刘峰 武方杰 余俨 于 2021-02-07 设计创作，主要内容包括：本发明公开了一种中间汽水分离的直流蒸汽发生的系统和方法,该系统包括蒸汽发生器和反应堆,其中：反应堆的出口接在蒸汽发生器的第三入口,蒸汽发生器的第三出口接在反应堆的入口,反应堆产生的热量通过反应堆的冷却剂的流动带入到蒸汽发生器中。该方法在启动过程中耗水量、耗热量较小,由于汽水分离器放置在蒸发器过热段前,机组在运行中,当给水发生波动时,水不会进入过热段,主蒸汽温度波动小,有利于机组的安全运行,机组突然全面停机后,再启动时,由于水不会进入温度较高的过热段,机组再启动过程中冷却时间较短,提高了机组的可用性。(The invention discloses a system and a method for generating direct current steam with intermediate steam-water separation, wherein the system comprises a steam generator and a reactor, and the method comprises the following steps: the outlet of the reactor is connected with the third inlet of the steam generator, the third outlet of the steam generator is connected with the inlet of the reactor, and the heat generated by the reactor is brought into the steam generator by the flow of the coolant of the reactor. The method has the advantages that the water consumption and the heat consumption are low in the starting process, the steam-water separator is placed in front of the overheating section of the evaporator, the unit is in operation, when the water supply fluctuates, the water cannot enter the overheating section, the main steam temperature fluctuation is low, the safe operation of the unit is facilitated, after the unit is suddenly and comprehensively stopped, and when the unit is restarted, the water cannot enter the overheating section with high temperature, the cooling time in the restarting process of the unit is short, and the usability of the unit is improved.)

1. A system for intermediate steam-water separation once-through steam generation is characterized by comprising a steam generator (2) and a reactor (10); wherein the content of the first and second substances,

the outlet of the reactor (10) is connected with the third inlet of the steam generator (2), the third outlet of the steam generator (2) is connected with the inlet of the reactor (10), and the heat generated by the reactor (10) is brought into the steam generator (2) through the flow of the coolant of the reactor (10).

2. The system for once-through steam generation with intermediate steam-water separation according to claim 1, characterized in that the steam generator (2) is a shell-and-tube heat exchanger, water and steam are arranged in the tube, the tube is called the secondary side of the steam generator (2), coolant of the reactor (10) is arranged outside the tube, the tube is called the primary side of the steam generator (2), the water on the secondary side of the steam generator (2) absorbs heat of the coolant of the reactor (10) on the primary side of the steam generator (2), the temperature is increased to generate steam, the steam generation is called steam generation, and the process of generating steam by water is completed in one process, and the process is called once-through.

3. An intermediate steam-water separation once-through steam generation system according to claim 1, characterized in that the steam generator (2) comprises an evaporation section (3) and a superheating section (7); a first inlet of the steam generator (2) is connected with an inlet of the evaporation section (3), an outlet of the evaporation section (3) is connected with a first outlet of the steam generator (2), a second inlet of the steam generator (2) is connected with an inlet of the superheating section (7), and an outlet of the superheating section (7) is connected with a second outlet of the steam generator (2).

4. An intermediate steam-water separation once-through steam generation system according to claim 1, characterized by further comprising a first valve group (1), a steam-water separator (4) and a second valve group (5); the outlet of the first valve group (1) is connected with the first inlet of the steam generator (2), the first outlet of the steam generator (2) is connected with the inlet of the steam-water separator (4), the first outlet of the steam-water separator (4) is connected with the second inlet of the steam generator (2), and the second outlet of the steam-water separator (4) is connected with the inlet of the second valve group (5).

5. An intermediate steam-water separation once-through steam generation system according to claim 4, characterized in that the steam-water separator (4) is located between the evaporator section (3) and the superheater section (7) of the steam generator (2), called intermediate steam-water separation, the steam-water separator (4) is used for steam-water separation of the steam-water mixture entering the steam generator (2), steam enters the second inlet of the steam generator (2) through the first outlet of the steam-water separator (4), and water enters the inlet of the second valve group (5) through the second outlet of the steam-water separator (4).

6. An intermediate steam-water separation once-through steam generation system according to claim 4, characterized in that the first valve group (1) and the second valve group (5) are composed of a stop valve and a regulating valve.

7. The system for once-through steam generation with intermediate steam-water separation according to claim 4, characterized by further comprising a steam turbine (9), a turbine bypass valve set (8) and a condenser (6); the outlet of the second valve group (5) is connected to the first inlet of the condenser (6), the second outlet of the steam generator (2) is divided into two parts, the first part is connected to the inlet of the steam turbine (9), the second part is connected to the inlet of the turbine bypass valve group (8), the outlet of the steam turbine (9) is connected to the second inlet of the condenser (6), and the outlet of the turbine bypass valve group (8) is connected to the third inlet of the condenser (6).

8. A method for intermediate steam-water separation once-through steam generation, which is based on the intermediate steam-water separation once-through steam generation system of claim 7, and comprises the following steps:

1) at the initial stage of starting a nuclear power unit, controlling water injection to a steam generator (2) through a regulating valve of a first valve group (1), and enabling water injected into the steam generator (2) to enter a steam-water separator (4) through an evaporation section (3);

2) when the evaporation section (3) is filled with water and the water level of the steam-water separator (4) is visible, the water discharge of the steam-water separator (4) is controlled through the regulating valve of the second valve group (5), and the normal water level of the steam-water separator (4) is maintained;

3) the power of the reactor (10) is increased, the temperature of the coolant of the reactor (10) is increased, and the coolant of the reactor (10) transfers heat to water in the evaporation section (3) through the steam generator (2);

4) along with the further improvement of the power of the reactor (10), steam is generated at the outlet of the evaporation section (3), a steam-water mixture is separated in a steam-water separator (4), water is discharged into a condenser (6) through a second valve group (5), and the steam enters the condenser (6) through a superheating section (7) in the steam generator (4) and a turbine bypass valve group (8);

5) controlling the pressure of the secondary side of the steam generator (2) and the pressure of the steam-water separator (4) by controlling a turbine bypass valve group (8);

6) along with the further increase of the power of the reactor (10), the steam generated at the outlet of the evaporation section (3) is increased, and the water quantity is reduced until the steam is completely changed into steam;

7) when the steam generated by the overheating section (7) meets the running requirement of the steam turbine (9), the steam enters the steam turbine (9), the steam turbine (9) runs with load, and the bypass valve group (8) of the steam turbine is gradually closed until the steam turbine is completely closed.

9. A method of intermediate steam-water separation once-through steam generation according to claim 8, characterized in that the load of the steam turbine (9) is adjusted synchronously with the change of the reactor (10) power.

Technical Field

The invention belongs to the technical field of nuclear power, and particularly relates to a direct-current steam generation system and method for intermediate steam-water separation.

Background

In the high-temperature gas-cooled reactor nuclear power plant constructed at present, a steam-water separator is arranged at an outlet of an evaporator (a superheating section), and water must flow through a superheater in a startup and shutdown stage. The current design has several problems:

(1) the unit consumes a large amount of water and heat in the starting process;

(2) when the unit is in operation, when the water supply fluctuates, the water directly enters the superheat section, the temperature fluctuation of the main steam is large, and the safe operation of the unit is not facilitated;

(3) after the unit is suddenly and completely shut down, the high-pressure heater and the low-pressure heater lose heating steam sources, the water supply temperature of the evaporator can only be heated to about 120 ℃, the outlet temperature of the evaporator is about 570 ℃, the evaporator needs to be cooled for a long time when water circulation is established in the two loops, and the usability of the unit is reduced.

Disclosure of Invention

The invention aims to provide a direct-current steam generation system and a direct-current steam generation method for intermediate steam-water separation aiming at the defects of the conventional unit system.

The invention is realized by adopting the following technical scheme:

a system for generating direct current steam with intermediate steam-water separation comprises a steam generator and a reactor; wherein the content of the first and second substances,

the outlet of the reactor is connected with the third inlet of the steam generator, the third outlet of the steam generator is connected with the inlet of the reactor, and the heat generated by the reactor is brought into the steam generator by the flow of the coolant of the reactor.

The steam generator is a shell-and-tube heat exchanger, water and steam are arranged in a tube, the tube is called a secondary side of the steam generator, coolant of a reactor is arranged outside the tube and called a primary side of the steam generator, the water on the secondary side of the steam generator absorbs the heat of the coolant of the reactor on the primary side of the steam generator, the temperature is increased to generate steam, the steam generation is called steam generation, and the process of generating steam by water is finished in one flow and called direct current.

In a further development of the invention, the steam generator comprises an evaporation section and a superheating section; the first inlet of the steam generator is connected with the inlet of the evaporation section, the outlet of the evaporation section is connected with the first outlet of the steam generator, the second inlet of the steam generator is connected with the inlet of the superheating section, and the outlet of the superheating section is connected with the second outlet of the steam generator.

The invention has the further improvement that the invention also comprises a first valve group, a steam-water separator and a second valve group; the outlet of the first valve group is connected with a first inlet of the steam generator, a first outlet of the steam generator is connected with an inlet of the steam-water separator, a first outlet of the steam-water separator is connected with a second inlet of the steam generator, and a second outlet of the steam-water separator is connected with an inlet of the second valve group.

The steam-water separator is positioned between the evaporation section and the overheating section of the steam generator and is called intermediate steam-water separation, the steam-water separator is used for separating steam from steam of a steam-water mixture entering the steam generator, steam enters the second inlet of the steam generator through the first outlet of the steam-water separator, and water enters the inlet of the second valve group through the second outlet of the steam-water separator.

The invention is further improved in that the first valve group and the second valve group are both composed of a stop valve and a regulating valve.

The invention has the further improvement that the system also comprises a steam turbine, a steam turbine bypass valve group and a condenser; the outlet of the second valve group is connected with the first inlet of the condenser, the second outlet of the steam generator is divided into two streams, the first stream is connected with the inlet of the steam turbine, the second stream is connected with the inlet of the turbine bypass valve group, the outlet of the steam turbine is connected with the second inlet of the condenser, and the outlet of the turbine bypass valve group is connected with the third inlet of the condenser.

A method for generating intermediate steam-water separation direct current steam is based on the intermediate steam-water separation direct current steam generation system and comprises the following steps:

1) at the initial stage of starting the nuclear power unit, controlling water injection to the steam generator through a regulating valve of a first valve group, and enabling water injected into the steam generator to enter a steam-water separator through an evaporation section;

2) when the evaporation section is filled with water and the water level of the steam-water separator is visible, the water discharge of the steam-water separator is controlled through the regulating valve of the second valve group, and the normal water level of the steam-water separator is maintained;

3) increasing the reactor power, increasing the reactor coolant temperature, and transferring heat from the reactor coolant to the water in the evaporation section through the steam generator;

4) along with the further improvement of the reactor power, steam is generated at the outlet of the evaporation section, a steam-water mixture is separated in a steam-water separator, water is discharged into a condenser through a second valve group, and the steam enters the condenser through a superheating section and a turbine bypass valve group in the steam generator;

5) controlling the pressure of the secondary side of the steam generator and the pressure of the steam-water separator by controlling a turbine bypass valve group;

6) along with the further improvement of the reactor power, the steam generated at the outlet of the evaporation section is increased, and the water quantity is reduced until the steam is completely changed into steam;

7) when the steam generated in the superheat section meets the turbine running requirement, the steam enters the turbine, the turbine runs under load, and the bypass valve set of the turbine is gradually closed until the bypass valve set is completely closed.

A further development of the invention consists in that the load of the steam turbine is adjusted synchronously with the change in the reactor power.

The invention has at least the following beneficial technical effects:

the system and the method for generating the intermediate steam-water separated direct-current steam have the following obvious advantages:

(1) the water consumption and the heat consumption of the unit are small in the starting process;

(2) because the steam-water separator is arranged in front of the overheating section of the evaporator, when the unit is in operation, water cannot enter the overheating section when the feed water fluctuates, the temperature fluctuation of the main steam is small, and the safe operation of the unit is facilitated;

(3) after the unit is suddenly and comprehensively stopped and restarted, because water cannot enter a superheat section with higher temperature, the cooling time in the restarting process of the unit is shorter, and the usability of the unit is improved.

Drawings

Fig. 1 is a block diagram of a system for direct steam generation with intermediate steam-water separation according to the present invention.

Description of reference numerals:

1. the system comprises a first valve group, a steam generator, a steam evaporation section, a steam-water separator, a second valve group, a steam condenser, a superheating section, a steam turbine bypass valve group, a steam turbine and a reactor, wherein the first valve group 2, the steam generator 3, the steam evaporation section 4, the steam-water separator 5, the second valve group 6, the steam condenser 7, the superheating section 8, the steam turbine bypass valve group 9.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1, the system for generating once-through steam by intermediate steam-water separation according to the present invention includes a first valve group 1, a steam generator 2, a steam-water separator 4, a second valve group 5, a condenser 6, a turbine bypass valve group 8, a turbine 9, and a reactor 10. The steam generator 2 comprises an evaporation section 3 and a superheating section 7; wherein, the first inlet of the steam generator 2 is connected with the inlet of the evaporation section 3, the outlet of the evaporation section 3 is connected with the first outlet of the steam generator 2, the second inlet of the steam generator 2 is connected with the inlet of the superheating section 7, and the outlet of the superheating section 7 is connected with the second outlet of the steam generator 2. The outlet of the reactor 10 is connected to the third inlet of the steam generator 2, the third outlet of the steam generator 2 is connected to the inlet of the reactor 10, and the heat generated by the reactor 10 is taken into the steam generator 2 by the flow of the coolant of the reactor 10. The outlet of the first valve group 1 is connected with the first inlet of the steam generator 2, the first outlet of the steam generator 2 is connected with the inlet of the steam-water separator 4, the first outlet of the steam-water separator 4 is connected with the second inlet of the steam generator 2, and the second outlet of the steam-water separator 4 is connected with the inlet of the second valve group 5. The outlet of the second valve set 5 is connected with the first inlet of the condenser 6, the second outlet of the steam generator 2 is divided into two parts, the first part is connected with the inlet of the steam turbine 9, the second part is connected with the inlet of the turbine bypass valve set 8, the outlet of the steam turbine 9 is connected with the second inlet of the condenser 6, and the outlet of the turbine bypass valve set 8 is connected with the third inlet of the condenser 6.

Preferably, the steam generator 2 is a shell-and-tube heat exchanger, water and steam are contained in the tube, which is called the secondary side of the steam generator 2, coolant of the reactor 10 is contained outside the tube, which is called the primary side of the steam generator 2, the temperature of the water on the secondary side of the steam generator 2 is increased to generate steam after absorbing heat of the coolant of the reactor 10 on the primary side of the steam generator 2, which is called steam generation, and the process of generating steam by water is completed in one flow, which is called direct current.

Preferably, the steam-water separator 4 is located between the evaporation section 3 and the superheating section 7 of the steam generator 2, which is called intermediate steam-water separation, the steam-water separator 4 is used for performing steam-water separation on steam-water mixture entering the steam generator 2, steam enters the second inlet of the steam generator 2 through the first outlet of the steam-water separator 4, and water enters the inlet of the second valve set 5 through the second outlet of the steam-water separator 4.

Preferably, the first valve group 1 and the second valve group 5 are both composed of a stop valve and a regulating valve.

The invention provides a direct-current steam generation method for intermediate steam-water separation, which comprises the following steps of:

1) at the initial stage of starting the nuclear power unit, water is injected into the steam generator 2 under the control of the regulating valve of the first valve group 1, and water injected into the steam generator 2 enters the steam-water separator 4 through the evaporation section 3;

2) when the evaporation section 3 is filled with water and the water level of the steam-water separator 4 is visible, the water discharge of the steam-water separator 4 is controlled by the regulating valve of the second valve group 5 to maintain the normal water level of the steam-water separator 4;

3) the power of the reactor 10 is increased, the temperature of the coolant of the reactor 10 is increased, and the coolant of the reactor 10 transfers heat to water in the evaporation section 3 through the steam generator 2;

4) along with the further improvement of the power of the reactor 10, steam is generated at the outlet of the evaporation section 3, a steam-water mixture is separated in the steam-water separator 4, water is discharged into the condenser 6 through the second valve group 5, and steam enters the condenser 6 through the superheating section 7 in the steam generator 4 and the turbine bypass valve group 8;

5) controlling the pressure of the secondary side of the steam generator 2 and the pressure of the steam-water separator 4 by controlling a turbine bypass valve group 8;

6) along with the further improvement of the power of the reactor 10, the steam generated at the outlet of the evaporation section 3 is increased, and the water quantity is reduced until the steam is completely changed into steam;

7) when the steam generated by the superheating section 7 meets the running requirement of the steam turbine 9, the steam enters the steam turbine 9, the steam turbine 9 operates with load, and the steam turbine bypass valve group 8 is gradually closed until the steam turbine bypass valve group is completely closed.

Thereafter, the load of the steam turbine 9 is synchronously adjusted as the power of the reactor 10 changes.