CN113963833B - Heat pump evaporation treatment system and method for radioactive waste liquid treatment - Google Patents

Abstract

The system comprises a first preheater, a second preheater, an evaporator, a vapor compressor, an electric vapor generator, a condensate flow regulating valve arranged between a condensate outlet of the electric vapor generator and an inlet of the first preheating chamber, a liquid level sensor arranged in the electric vapor generator, and a controller correspondingly connected with the condensate flow regulating valve and the liquid level sensor respectively. The heat pump evaporation treatment system provided by the disclosure is provided with the condensate control device, so that the actual liquid level in the electric steam generator can be monitored in real time, and the flow of steam condensate flowing out of the electric steam generator is regulated based on the actual liquid level, so that the problems of dry burning or full tank overflow of the electric steam generator can be effectively avoided, and the service life of equipment is prolonged.

Description

A heat pump evaporation treatment system and method for radioactive waste liquid treatment

Technical field

The present disclosure relates to the technical field of waste liquid treatment, and in particular to a heat pump evaporation treatment system and method for radioactive waste liquid treatment.

Background technique

With the advancement of science and technology, nuclear energy, as a clean energy with great promotion value, is widely used in many fields. In the production process of nuclear energy, radioactive waste liquid will be produced during the nuclear fuel cycle. The radioactive waste liquid contains a small amount of radionuclides and salts of different concentrations, which is harmful to the human body and the environment. Therefore, it needs to be purified before discharge.

The current method used to treat radioactive waste liquid is mainly the evaporation concentration method. This method sends the preheated radioactive waste liquid into the evaporator, and uses high-temperature steam to heat the evaporator, so that the radioactive waste liquid is separated into steam and concentrated liquid. The steam is directly discharged after condensation, and the concentrated liquid is further processed.

Chinese patent CN204303367U discloses a low-level radioactive waste liquid treatment system. The system is equipped with a steam compressor and an electric steam generator, which can evaporate the radioactive waste liquid by consuming electrical energy without the need for external steam supply. Provides heating steam, thus having better energy saving effect.

However, in the process of realizing the present disclosure, the inventor discovered that the electric steam generator in the above system has problems of dry burning of the empty tank or overflowing of the full tank.

Contents of the invention

The purpose of this disclosure is to solve the problems of dry burning of empty electric steam generator tanks or overflowing of full tanks existing in existing radioactive waste liquid treatment systems, and to provide a heat pump evaporation treatment system and method for radioactive waste liquid treatment.

In order to achieve the above objects, the present disclosure provides a heat pump evaporation treatment system for radioactive waste liquid treatment, which system includes a first preheater, a second preheater, an evaporator, a steam compressor, an electric steam generator and a condensation unit. Liquid control device, the first preheater has a first raw liquid chamber and a first preheating chamber, the second preheater has a second raw liquid chamber and a second preheating chamber, the evaporator has an evaporation chamber and heating chamber;

The first raw liquid chamber, the second raw liquid chamber, the evaporation chamber and the steam compressor are connected in sequence, and the outlet of the steam compressor and the compensation steam outlet of the electric steam generator are respectively connected with the heating The inlet of the chamber is connected, the steam outlet of the heating chamber is connected with the inlet of the second preheating chamber, the condensate outlet of the heating chamber and the outlet of the second preheating chamber are connected with the electric steam generator respectively. The condensate inlet of the electric steam generator is connected with the inlet of the first preheating chamber;

Wherein, the condensate control device includes:

A condensate flow regulating valve is provided between the condensate outlet of the electric steam generator and the inlet of the first preheating chamber, and is used to control the flow of the steam condensate entering the first preheating chamber. Flow is regulated;

A liquid level sensor, disposed in the electric steam generator, for measuring the liquid level in the electric steam generator; and

A controller, respectively connected to the condensate flow regulating valve and the liquid level sensor, for obtaining the actual liquid level in the electric steam generator from the liquid level sensor, and based on the actual liquid level, The opening of the condensate flow regulating valve is adjusted to adjust the flow of the steam condensate entering the first preheating chamber.

Optionally, the system also includes a feed tank, a purification tower, a hot water pump and an external discharge pipe;

The outlet of the feed tank is connected with the inlet of the first raw liquid chamber;

The purification tower is arranged between the evaporation chamber and the steam compressor, the inlet of the purification tower is connected to the outlet of the evaporation chamber, and the outlet of the purification tower is connected to the inlet of the steam compressor;

The hot water pump is disposed between the electric steam generator and the first preheating chamber, the inlet of the hot water pump is connected to the condensate outlet of the electric steam generator, and the outlet of the hot water pump is connected to the condensate outlet of the electric steam generator. The inlet of the first preheating chamber is connected for sending the steam condensate in the electric steam generator into the first preheating chamber;

The outer discharge pipe is connected with the outlet of the first preheating chamber.

The present disclosure also provides a method for treating radioactive waste liquid using any one of the systems described above, which method includes:

utilizing the controller to obtain the actual liquid level in the electric steam generator from the liquid level sensor;

Compare the actual liquid level with the preset liquid level;

When the actual liquid level is lower than the preset liquid level, use the controller to control the condensate flow regulating valve to reduce the opening of the condensate flow regulating valve;

When the actual liquid level is higher than the preset liquid level, the controller is used to control the condensate flow regulating valve to increase the opening of the condensate flow regulating valve.

Optionally, the preset liquid level is 50-65% of the internal depth of the electric steam generator, preferably 55-60%.

Optionally, when adjusting the opening of the condensate flow regulating valve, the adjustment range is such that the total opening of the condensate flow regulating valve is 25% to 35%.

Optionally, the method also includes:

Send the radioactive waste liquid to be treated sequentially into the first raw liquid chamber of the first preheater and the second raw liquid chamber of the second preheater for preheating treatment;

Let the preheated radioactive waste liquid enter the evaporation chamber of the evaporator for evaporation treatment to obtain secondary steam and concentrated waste liquid;

Let the secondary steam enter the steam compressor for pressure and temperature raising treatment to obtain high-temperature steam, and return the high-temperature steam as a heat source to the heating chamber of the evaporator for heat exchange;

Send the partially uncondensed high-temperature steam and non-condensable gas in the heating chamber as a heat source into the second preheating chamber of the second preheater for heat exchange;

Send the steam condensate generated by heat exchange in the heating chamber and the steam condensate generated by heat exchange in the second preheating chamber to the electric steam generator respectively;

Evaporate part of the steam condensate in the electric steam generator to obtain compensation steam, and use the compensation steam as a heat source to enter the heating chamber of the evaporator for heat exchange;

Part of the steam condensate in the electric steam generator is used as a heat source to enter the first preheating chamber of the first preheater for heat exchange, and the heat-exchanged steam condensate is discharged from the first preheating chamber. Export for discharge.

Optionally, after being preheated by the first preheater, the temperature of the radioactive waste liquid rises to 70°C to 85°C, and after being preheated by the second preheater, the temperature of the radioactive waste liquid is The temperature rises to 90℃~98℃.

Optionally, after the steam compressor performs pressure and temperature raising treatment, the pressure of the high-temperature steam is 50kPa˜80kPa, and the temperature is 110°C˜120°C.

Optionally, the temperature of the steam condensate entering the first preheating chamber from the electric steam generator is 110°C to 120°C;

The temperature of the steam condensate discharged from the outlet of the first preheating chamber is 40°C to 55°C.

Optionally, the temperature of the compensation steam is 110°C to 120°C.

Through the above technical solution, the heat pump evaporation processing system provided by the present disclosure is provided with a condensate control device, which can monitor the actual liquid level in the electric steam generator in real time, and condense the steam flowing out of the electric steam generator based on the actual liquid level. The flow of liquid is adjusted, which can effectively avoid problems such as dry burning of empty electric steam generator tanks or overflow of full tanks, and is beneficial to extending the service life of the equipment.

Other features and advantages of the present disclosure will be described in detail in the detailed description that follows.

Description of the drawings

The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. They are used to explain the present disclosure together with the following specific embodiments, but do not constitute a limitation of the present disclosure. In the attached picture:

Figure 1 schematically shows a structural diagram of a heat pump evaporation treatment system for radioactive waste liquid treatment according to an embodiment of the present disclosure;

FIG. 2 schematically shows a structural diagram of a condensate treatment flow path according to an embodiment of the present disclosure.

Explanation of reference signs

1 First preheater 2 Second preheater

3 Evaporator 4 Purification tower

5 Steam compressor 6 Electric steam generator

7 Condensate flow regulating valve 8 External discharge pipe

9 Feed trough 10 Hot water pump

11 Level sensor 12 Controller

Detailed ways

Specific embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described here are only used to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.

Figure 1 schematically shows a structural diagram of a heat pump evaporation treatment system for radioactive waste liquid treatment according to an embodiment of the present disclosure.

As shown in Figure 1, the system may include a first preheater 1, a second preheater 2, an evaporator 3, a steam compressor 5, an electric steam generator 6 and a condensate control device. The first preheater The evaporator 1 has a first raw liquid chamber and a first preheating chamber, the second preheater 2 has a second raw liquid chamber and a second preheating chamber, and the evaporator 3 has an evaporation chamber and a heating chamber.

Wherein, the first raw liquid chamber, the second raw liquid chamber, the evaporation chamber and the steam compressor 5 are connected in sequence, and the outlet of the steam compressor 5 and the compensation steam outlet of the electric steam generator 6 are respectively connected with the inlet of the heating chamber, the steam outlet of the heating chamber is connected with the inlet of the second preheating chamber, the condensate outlet of the heating chamber and the outlet of the second preheating chamber are respectively connected with the The condensate inlet of the electric steam generator 6 is connected, and the condensate outlet of the electric steam generator 6 is connected with the inlet of the first preheating chamber.

In the present disclosure, specifically, the first raw liquid chamber, the second raw liquid chamber and the evaporation chamber constitute a waste liquid treatment flow path for preheating and evaporating radioactive waste liquid; the steam compressor, the heating chamber and the second The preheating chamber forms a steam treatment flow path, which is used to provide heating steam for preheating and evaporation of radioactive waste liquid; the electric steam generator and the first preheating chamber form a condensate treatment flow path, which is used for preheating and evaporating radioactive waste liquid. Provide preheating water and discharge the cooled steam condensate.

The radioactive waste liquid enters from the entrance of the first raw liquid chamber, and after being preheated by the first raw liquid chamber and the second raw liquid chamber, enters the evaporation chamber of the evaporator, and evaporates in the evaporation chamber to generate secondary steam; the secondary steam enters the vapor compression chamber machine, and is pressurized and heated in the steam compressor to become high-temperature steam; the high-temperature steam enters the heating chamber of the evaporator for heat exchange, providing heat for the evaporation process of radioactive waste liquid in the evaporation chamber. The high-temperature steam after heat exchange The condensed steam condensate enters the electric steam generator; part of the uncondensed high-temperature steam and non-condensable gas in the evaporation chamber enters the second preheating chamber for heat exchange, providing heat for preheating the radioactive waste liquid in the second raw liquid chamber. The steam condensate generated by heat enters the electric steam generator, and the non-condensable gas is directly discharged from the second preheating chamber; part of the steam condensate entering the electric steam generator is heated and boiled to generate compensation steam, and the other part enters the first preheating chamber. , providing heat for preheating the radioactive waste liquid in the first liquid chamber; the compensation steam generated in the electric steam generator enters the heating chamber of the evaporator for heat exchange, and the steam condensate in the first preheating chamber is exchanging heat Then discharge directly.

FIG. 2 schematically shows a structural diagram of a condensate treatment flow path according to an embodiment of the present disclosure. As shown in Figure 2, the condensate treatment flow is composed of the electric steam generator 5 and the first preheating chamber of the first preheater 1. The condensate treatment flow is provided with a condensate control device, including: a condensate flow regulating valve. 7. Disposed between the condensate outlet of the electric steam generator 6 and the inlet of the first preheating chamber, used to adjust the flow rate of the steam condensate entering the first preheating chamber. ; Liquid level sensor 11 is provided in the electric steam generator 6 for measuring the liquid level in the electric steam generator 6; controller 12 is respectively connected with the condensate flow regulating valve 7 and the The liquid level sensor 11 is connected for obtaining the actual liquid level in the electric steam generator 6 from the liquid level sensor 11 and adjusting the opening of the condensate flow rate valve 7 based on the actual liquid level. Adjustment is performed to adjust the flow rate of the steam condensate entering the first preheating chamber.

Through the above technical solution, the heat pump evaporation treatment system has at least the following beneficial effects:

(1) The heat pump evaporation treatment system uses the secondary steam generated by the waste liquid evaporation treatment as the heating steam required for the waste liquid evaporation treatment. The heating steam is converted into condensed steam that can be directly discharged during the process of providing heat for the waste liquid evaporation treatment. liquid, therefore, the present disclosure eliminates the need to install a steam condensing device, and realizes the reuse of steam heat, which has the advantage of low consumption and energy saving;

(2) A liquid level sensor for monitoring the liquid level in the electric steam generator and a condensate flow regulating valve for controlling the outflow flow of steam condensate in the electric steam generator are provided, and the liquid level sensor is connected to the condensate The flow control valve is automatically associated to realize the control method of regulating the steam condensate outflow flow according to the electric steam generator liquid level. This can effectively avoid the low electric steam generator liquid level caused by the steam condensate outflow flow being too large or too small. Or a high problem.

Specifically, the first preheater uses water-water heat exchange to preheat the radioactive waste liquid. The heat source is the steam condensate in the first preheating chamber. After heat exchange, the steam condensate in the first preheating chamber can be Direct discharge. The radioactive waste liquid is evaporated in the evaporation chamber of the evaporator to produce secondary steam, and the steam is condensed into steam condensate in the evaporation chamber of the evaporator and the second preheating chamber of the second preheater. Under normal conditions, the radioactive waste liquid The input amount of liquid is equal to the evaporation amount of radioactive waste liquid, the evaporation amount of radioactive waste liquid is equal to the reflux amount of steam condensate, and the reflux amount of steam condensate is equal to the output amount of steam condensate, that is, without considering the evaporator When discharging concentrated waste liquid, the input volume of radioactive waste liquid is equal to the output volume of steam condensate. Therefore, in order to ensure the smooth operation of the system, it is usually necessary to control the output volume of steam condensate liquid.

However, during the operation of the system, the evaporation amount of the radioactive waste liquid may fluctuate. When the evaporation amount is low, the return flow rate of the steam condensate is low. If the steam condensate is still output according to the previous output volume, it will cause The liquid level of the electric steam generator continues to decrease, eventually causing the electric steam generator to be empty and the electric heating element to be exposed and dry. When the evaporation amount is high, the return flow of the steam condensate will be high. If the steam condensate still outputs according to the previous If the amount is output, the liquid level of the electric steam generator will continue to rise, and eventually the space inside the electric steam generator will be reduced or even disappear. This will further cause the compensation steam generated by the electric steam generator to be reduced, and it will not be able to provide electric steam. The heating chamber provides enough heating steam to affect the treatment effect of the system. The present disclosure can effectively solve the above problems by adjusting the output of steam condensate to keep the liquid level of the electric steam generator constant.

In addition, the preheating capacity of the first preheater is fixed and is usually set so that when the amount of steam condensate in the first preheating chamber is equal to the amount of radioactive waste liquid in the first raw liquid chamber, the first preheater can The radioactive waste liquid is preheated to a preset temperature. Therefore, the present disclosure controls the output of the steam condensate and can also ensure the stable operation of the first preheater and ensure that the first preheater can absorb the radioactive waste liquid entering it. Preheat to preset temperature.

According to the present disclosure, the system may also include a feed tank 9, a purification tower 4, a hot water pump 10 and an external discharge pipe 8; the outlet of the feed tank 9 is connected to the inlet of the first raw liquid chamber; the purification The tower 4 is arranged between the evaporation chamber and the steam compressor 5. The inlet of the purification tower 4 is connected with the outlet of the evaporation chamber, and the outlet of the purification tower 4 is connected with the inlet of the steam compressor 5. Communicated; the hot water pump 10 is arranged between the electric steam generator 6 and the first preheating chamber, and the inlet of the hot water pump 10 is connected with the condensate outlet of the electric steam generator 6. The outlet of the hot water pump 10 is connected with the inlet of the first preheating chamber, and is used to send the steam condensate in the electric steam generator 6 into the first preheating chamber; the external discharge pipe 8 is connected with the inlet of the first preheating chamber. The outlet of the first preheating chamber is connected.

According to the present disclosure, a first filter screen may be provided at the outlet of the evaporation chamber, a second filter screen may be provided in the purification tower 4, and the secondary steam from the evaporation chamber passes through the first filter screen and After the second filter, it enters the steam compressor 5 .

The first filter and the second filter can effectively remove small water droplets entrained in the steam that do not meet the emission standard, and prevent them from being discharged to the outside through the steam treatment flow path and the condensate treatment flow path.

The present disclosure also provides a method for treating radioactive waste liquid using any one of the systems described above. The method may include: using the controller to obtain the actual liquid level in the electric steam generator from the liquid level sensor; The actual liquid level is compared with the preset liquid level; when the actual liquid level is lower than the preset liquid level, the controller is used to control the condensate flow regulating valve to reduce the The opening of the condensate flow regulating valve; when the actual liquid level is higher than the preset liquid level, the controller is used to control the condensate flow regulating valve to increase the condensate flow regulating valve. valve opening.

In the present disclosure, specifically, a controller commonly used in the field can be used to automatically adjust the opening of the condensate flow regulating valve, such as a programmable logic controller (PLC system). The amount of decrease or increase in the opening of the condensate flow regulating valve can be determined according to actual needs, and will not be described in detail in this disclosure.

According to the present disclosure, the preset liquid level may be 50-65% of the internal depth of the electric steam generator, preferably 55-60%. In this disclosure, the liquid level in the electric steam generator is set to a fixed value, and the output of the steam condensate is adjusted according to changes in the liquid level in the electric steam generator, so that the output of the steam condensate is gradually equal to its return flow. As a result, the system operation tends to be stable, which can adjust the performance and operational stability of the system while ensuring that the electric steam generator always operates stably, which is conducive to ensuring the long-term stable operation of the system.

According to the present disclosure, when adjusting the opening of the condensate flow regulating valve, the adjustment range may be such that the total opening of the condensate flow regulating valve is 25% to 35%.

Optionally, the method may further include: sequentially sending the radioactive waste liquid to be treated into the first raw liquid chamber of the first preheater and the second raw liquid chamber of the second preheater for preheating. Processing; causing the preheated radioactive waste liquid to enter the evaporation chamber of the evaporator for evaporation treatment to obtain secondary steam and concentrated waste liquid; causing the secondary steam to enter the steam compressor for pressurization The temperature is raised to obtain high-temperature steam, and the high-temperature steam is returned to the heating chamber of the evaporator as a heat source for heat exchange; part of the uncondensed high-temperature steam and non-condensable gas in the heating chamber are sent into the heating chamber as a heat source. Heat exchange is performed in the second preheating chamber of the second preheater; the steam condensate generated by heat exchange in the heating chamber and the steam condensate generated by heat exchange in the second preheating chamber are sent into In the electric steam generator; evaporate part of the steam condensate in the electric steam generator to obtain compensation steam, and use the compensation steam as a heat source to enter the heating chamber of the evaporator for heat exchange; Part of the steam condensate in the electric steam generator enters the first preheating chamber of the first preheater as a heat source for heat exchange, and the heat-exchanged steam condensate is discharged from the outlet of the first preheating chamber. .

According to the present disclosure, after being preheated by the first preheater, the temperature of the radioactive waste liquid rises to 70°C to 85°C, and after being preheated by the second preheater, the temperature of the radioactive waste liquid is The temperature rises to 90℃~98℃.

According to the present disclosure, after the steam compressor performs pressure and temperature raising treatment, the pressure of the high-temperature steam can be 50kPa˜80kPa, and the temperature can be 110°C˜120°C.

According to the present disclosure, the temperature of the steam condensate entering the first preheating chamber from the electric steam generator may be 110°C to 120°C; the temperature of the steam condensate discharged from the outlet of the first preheating chamber The temperature can be 40℃~55℃.

According to the present disclosure, the temperature of the compensation steam may be 110°C to 120°C.

The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above-mentioned embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure. These simple modifications all belong to the protection scope of the present disclosure.

In addition, it should be noted that each of the specific technical features described in the above-mentioned specific embodiments can be combined in any suitable manner without conflict. In order to avoid unnecessary repetition, this disclosure describes various possible combinations. The combination method will not be further explained.

In addition, any combination of various embodiments of the present disclosure can also be carried out, and as long as they do not violate the idea of the present disclosure, they should also be regarded as the contents disclosed in the present disclosure.

Claims (11)

1. A heat pump evaporation treatment system for radioactive waste liquid treatment, characterized in that the system comprises a first preheater, a second preheater, an evaporator, a vapor compressor, an electric vapor generator and a condensate control device, wherein the first preheater is provided with a first stock solution chamber and a first preheating chamber, the second preheater is provided with a second stock solution chamber and a second preheating chamber, and the evaporator is provided with an evaporation chamber and a heating chamber;

the first stock solution chamber, the second stock solution chamber, the evaporation chamber and the vapor compressor are sequentially communicated, an outlet of the vapor compressor and a compensation vapor outlet of the electric vapor generator are respectively communicated with an inlet of the heating chamber, a vapor outlet of the heating chamber is communicated with an inlet of the second preheating chamber, a condensate outlet of the heating chamber and an outlet of the second preheating chamber are respectively communicated with a condensate inlet of the electric vapor generator, and a condensate outlet of the electric vapor generator is communicated with an inlet of the first preheating chamber;

wherein the condensate control device comprises:

the condensate flow regulating valve is arranged between a condensate outlet of the electric steam generator and an inlet of the first preheating chamber and is used for regulating the flow of steam condensate entering the first preheating chamber;

the liquid level sensor is arranged in the electric steam generator and is used for measuring the liquid level in the electric steam generator; and

and the controller is respectively connected with the condensate flow regulating valve and the liquid level sensor, and is used for acquiring the actual liquid level in the electric steam generator from the liquid level sensor, and regulating the opening of the condensate flow regulating valve based on the actual liquid level so as to regulate the flow of the steam condensate entering the first preheating chamber.

2. The system of claim 1, further comprising a feed tank, a purge column, a hot water pump, and an off-line conduit;

the outlet of the feed tank is communicated with the inlet of the first stock solution chamber;

the purification tower is arranged between the evaporation chamber and the vapor compressor, the inlet of the purification tower is communicated with the outlet of the evaporation chamber, and the outlet of the purification tower is communicated with the inlet of the vapor compressor;

the hot water pump is arranged between the electric steam generator and the first preheating chamber, the inlet of the hot water pump is communicated with the condensate outlet of the electric steam generator, and the outlet of the hot water pump is communicated with the inlet of the first preheating chamber and is used for feeding the steam condensate in the electric steam generator into the first preheating chamber;

the outer-row pipeline is communicated with an outlet of the first preheating chamber.

3. A method of treating radioactive waste using the system of claim 1 or 2, the method comprising:

acquiring an actual liquid level in the electric steam generator from the liquid level sensor by using the controller;

comparing the actual liquid level with a preset liquid level;

when the actual liquid level is lower than the preset liquid level, controlling the condensate flow regulating valve by using the controller to reduce the opening of the condensate flow regulating valve;

and under the condition that the actual liquid level is higher than the preset liquid level, controlling the condensate flow regulating valve by using the controller so as to increase the opening degree of the condensate flow regulating valve.

4. The method of claim 3, wherein the step of,

the preset liquid level is 50-65% of the depth inside the electric steam generator.

5. The method of claim 4, wherein the predetermined level is 55% to 60% of the depth inside the electric steam generator.

6. A method according to claim 3, wherein the opening of the condensate flow control valve is adjusted by an amount of 25 to 35% of the total opening of the condensate flow control valve.

7. The method according to any one of claims 3 to 6, further comprising:

the radioactive waste liquid to be treated is sequentially sent into a first stock solution chamber of the first preheater and a second stock solution chamber of the second preheater for preheating treatment;

enabling the preheated radioactive waste liquid to enter an evaporation chamber of the evaporator for evaporation treatment to obtain secondary steam and concentrated waste liquid;

enabling the secondary steam to enter the steam compressor for pressurizing and heating treatment to obtain high-temperature steam, and returning the high-temperature steam as a heat source to a heating chamber of the evaporator for heat exchange;

feeding part of the high-temperature steam which is not condensed in the heating chamber and the non-condensable gas into a second preheating chamber of the second preheater as heat sources for heat exchange;

respectively feeding the steam condensate generated by heat exchange in the heating chamber and the steam condensate generated by heat exchange in the second preheating chamber into the electric steam generator;

evaporating part of steam condensate in the electric steam generator to obtain compensation steam, and enabling the compensation steam to be used as a heat source to enter a heating chamber of the evaporator for heat exchange;

and enabling part of steam condensate in the electric steam generator to be used as a heat source to enter a first preheating chamber of the first preheater for heat exchange, and discharging the steam condensate after heat exchange from an outlet of the first preheating chamber.

8. The method of claim 7, wherein the temperature of the radioactive waste after preheating by the first preheater is raised to 70 ℃ to 85 ℃, and the temperature of the radioactive waste after preheating by the second preheater is raised to 90 ℃ to 98 ℃.

9. The method according to claim 7, wherein the high-temperature steam has a pressure of 50kPa to 80kPa and a temperature of 110 ℃ to 120 ℃ after the heating-up treatment by the vapor compressor.

10. The method of claim 7, wherein the temperature of the steam condensate entering the first preheating chamber from the electric steam generator is 110 ℃ to 120 ℃;

the temperature of the steam condensate discharged from the outlet of the first preheating chamber is 40-55 ℃.

11. The method of claim 7, wherein the temperature of the make-up steam is 110 ℃ to 120 ℃.