Disclosure of Invention
The purpose of this disclosure is to solve the problem that the empty pot of electric steam generator dry combustion or full pot overflow that exists in the existing radioactive liquid waste treatment system, provides a heat pump evaporation processing system and method for radioactive liquid waste treatment.
In order to achieve the above object, the present disclosure provides a heat pump evaporation treatment system for radioactive liquid waste treatment, the system including a first preheater having a first raw liquid chamber and a first preheating chamber, a second preheater having a second raw liquid chamber and a second preheating chamber, an evaporator having an evaporation chamber and a heating chamber, a vapor compressor, an electric vapor generator, and a condensate control device;
the first raw liquid chamber, the second raw liquid chamber, the evaporation chamber and the steam compressor are sequentially communicated, an outlet of the steam compressor and a compensation steam outlet of the electric steam generator are respectively communicated with an inlet of the heating chamber, a steam 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 steam generator, and a condensate outlet of the electric steam generator is communicated with an inlet of the first preheating chamber;
wherein the condensate control device comprises:
a condensate flow regulating valve arranged between a condensate outlet of the electric steam generator and an inlet of the first preheating chamber and used for regulating the flow of the steam condensate entering the first preheating chamber;
the liquid level sensor is arranged in the electric steam generator and 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 degree 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.
Optionally, the system further comprises a feed tank, a purification tower, a hot water pump and an external discharge pipe;
an outlet of the feeding groove is communicated with an inlet of the first raw liquid chamber;
the purification tower is arranged between the evaporation chamber and the vapor compressor, an inlet of the purification tower is communicated with an outlet of the evaporation chamber, and an outlet of the purification tower is communicated with an inlet of the vapor compressor;
the hot water pump is arranged between the electric steam generator and the first preheating chamber, an inlet of the hot water pump is communicated with a condensate outlet of the electric steam generator, and an outlet of the hot water pump is communicated with an inlet of the first preheating chamber and is used for conveying steam condensate in the electric steam generator into the first preheating chamber;
the outer discharge pipeline is communicated with an outlet of the first preheating chamber.
The present disclosure also provides a method of treating radioactive waste using the system of any of the above, 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;
under the condition that 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 degree of the condensate flow regulating valve;
and under the condition that the actual liquid level is higher than the preset liquid level, the controller is utilized to control the condensate flow regulating valve so as to increase the opening degree of the condensate flow regulating valve.
Optionally, the preset liquid level is 50-65%, preferably 55-60% of the inner depth of the electric steam generator.
Optionally, when the opening degree of the condensate flow regulating valve is regulated, the regulating range is that the total opening degree of the condensate flow regulating valve is 25-35%.
Optionally, the method further comprises:
sequentially feeding radioactive waste liquid to be treated into a first raw liquid chamber of the first preheater and a second raw liquid chamber of the second preheater for preheating treatment;
the preheated radioactive waste liquid enters an evaporation chamber of the evaporator for evaporation treatment to obtain secondary steam and concentrated waste liquid;
the secondary steam enters the steam compressor to be pressurized and heated to obtain high-temperature steam, and the high-temperature steam is used as a heat source to return to a heating chamber of the evaporator for heat exchange;
feeding 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 steam condensate generated by heat exchange in the heating chamber and 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 enter a heating chamber of the evaporator as a heat source for heat exchange;
and part of steam condensate in the electric steam generator is used as a heat source to enter a first preheating chamber of the first preheater for heat exchange, and the steam condensate after heat exchange is discharged from an outlet of the first preheating chamber.
Optionally, after being preheated by the first preheater, the temperature of the radioactive waste liquid is increased to 70 ℃ to 85 ℃, and after being preheated by the second preheater, the temperature of the radioactive waste liquid is increased to 90 ℃ to 98 ℃.
Optionally, after the pressurization and temperature rise treatment is performed by the steam compressor, the pressure of the high-temperature steam is 50kPa to 80kPa, and the temperature is 110 ℃ to 120 ℃.
Optionally, 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 ℃ to 55 ℃.
Optionally, the temperature of the compensation steam is 110 ℃ to 120 ℃.
Through above-mentioned technical scheme, be equipped with condensate controlling means among the heat pump evaporation treatment system that this disclosure provided, actual liquid level in can the real-time supervision electric steam generator, and based on actual liquid level adjusts the flow of the steam condensate of play electric steam generator, and this can effectively avoid the appearance of electric steam generator empty can dry combustion or full jar overflow scheduling problem, is favorable to prolonging the life of equipment.
Additional features and advantages of the disclosure will be set forth in the detailed description which follows.
Detailed Description
The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.
Fig. 1 schematically shows a schematic structural diagram of a heat pump evaporation treatment system for radioactive liquid waste treatment according to an embodiment of the present disclosure.
As shown in fig. 1, the system may include a first preheater 1 having a first raw liquid chamber and a first preheating chamber, a second preheater 2 having a second raw liquid chamber and a second preheating chamber, an evaporator 3 having an evaporation chamber and a heating chamber, a vapor compressor 5, an electric vapor generator 6, and a condensate control device.
The first raw liquid chamber, the second raw liquid chamber, the evaporation chamber and the vapor compressor 5 are sequentially communicated, an outlet of the vapor compressor 5 and a compensation vapor outlet of the electric vapor generator 6 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 6, and a condensate outlet of the electric vapor generator 6 is communicated with an 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 performing a preheating treatment and an evaporation treatment on the radioactive waste liquid; the steam compressor, the heating chamber and the second preheating chamber form a steam treatment flow path for providing heating steam for preheating and evaporating the radioactive waste liquid; the electric steam generator and the first preheating chamber form a condensate treatment flow path for providing preheating water for presetting the radioactive waste liquid and discharging cooled steam condensate.
The radioactive waste liquid enters from an inlet of the first stock solution chamber, is preheated by the first stock solution chamber and the second stock solution chamber in sequence, enters an evaporation chamber of the evaporator and is evaporated in the evaporation chamber to generate secondary steam; the secondary steam enters a steam compressor and is pressurized and heated in the steam compressor to become high-temperature steam; the high-temperature steam enters a heating chamber of the evaporator for heat exchange to provide heat for the evaporation process of the radioactive waste liquid in the evaporation chamber, and the high-temperature steam after heat exchange is condensed into steam condensate to enter an electric steam generator; part of uncondensed high-temperature steam and non-condensable gas in the evaporation chamber enter a second preheating chamber for heat exchange to provide heat for preheating the radioactive waste liquid in the second stock solution chamber, steam condensate generated by heat exchange enters an electric steam generator, and the non-condensable gas is directly discharged from the second preheating chamber; one part of the steam condensate entering the electric steam generator is heated and boiled to generate compensation steam, and the other part of the steam condensate enters the first preheating chamber to provide heat for preheating the radioactive waste liquid in the first stock solution chamber; and the compensation steam generated in the electric steam generator enters a heating chamber of the evaporator for heat exchange, and the steam condensate in the first preheating chamber is directly discharged after heat exchange.
FIG. 2 schematically illustrates a structural schematic of a condensate treatment flow path according to an embodiment of the present disclosure. As shown in fig. 2, the condensate treatment flow path is composed of the electric steam generator 5 and the first preheating chamber of the first preheater 1, and the condensate treatment flow path is provided with a condensate control device, including: a condensate flow regulating valve 7, which is arranged between the condensate outlet of the electric steam generator 6 and the inlet of the first preheating chamber, and is used for regulating the flow of the steam condensate entering the first preheating chamber; a liquid level sensor 11 disposed in the electric steam generator 6 for measuring a liquid level in the electric steam generator 6; and the controller 12 is connected with the condensate flow regulating valve 7 and the liquid level sensor 11 respectively, and is used for acquiring the actual liquid level in the electric steam generator 6 from the liquid level sensor 11, and regulating the opening degree of the condensate flow regulating valve 7 based on the actual liquid level so as to regulate the flow of the steam condensate entering the first preheating chamber.
Through the technical scheme, the heat pump evaporation treatment system at least has the following beneficial effects:
(1) the heat pump evaporation treatment system uses secondary steam generated by waste liquid evaporation treatment as heating steam required by the waste liquid evaporation treatment, and the heating steam is converted into steam condensate which can be directly discharged in the process of providing heat for the waste liquid evaporation treatment, so that a steam condensing device is not required to be arranged, the steam heat is recycled, and the heat pump evaporation treatment system has the advantages of low consumption and energy saving;
(2) the liquid level sensor used for monitoring the liquid level height in the electric steam generator is arranged, the condensate flow regulating valve used for controlling the steam condensate outflow in the electric steam generator is arranged, the liquid level sensor and the condensate flow control valve are automatically associated, the control mode of regulating the steam condensate outflow according to the liquid level of the electric steam generator is realized, and the problem that the liquid level of the electric steam generator is low or high due to large or small outflow of the steam condensate can be effectively avoided.
Specifically, the first preheater preheats the radioactive waste liquid in a water-water heat exchange mode, the heat source is steam condensate in the first preheating chamber, and the steam condensate in the first preheating chamber can be directly discharged after heat exchange. The radioactive waste liquid is evaporated in the evaporation chamber of the evaporator to generate secondary steam, the steam is condensed into steam condensate in the evaporation chamber of the evaporator and the second preheating chamber of the second preheater, the input quantity of the radioactive waste liquid is equal to the evaporation quantity of the radioactive waste liquid in a normal state, the evaporation quantity of the radioactive waste liquid is equal to the reflux quantity of the steam condensate, and the reflux quantity of the steam condensate is equal to the output quantity of the steam condensate, namely under the condition that the concentrated waste liquid in the evaporator is not considered for discharging, the input quantity of the radioactive waste liquid is equal to the output quantity of the steam condensate, so that the output quantity of the steam condensate is generally required to be controlled in order to ensure the stable operation of the system.
However, in the operation process of the system, the evaporation amount of the radioactive waste liquid may fluctuate, when the evaporation amount is relatively low, the reflux amount of the steam condensate is relatively low, and if the steam condensate is still output according to the previous output amount, the liquid level of the electric steam generator is continuously reduced, and finally the electric steam generator is empty, and the electric heating element is exposed and dried; when the evaporation amount is higher, the reflux amount of the steam condensate is higher, if the steam condensate is still output according to the previous output amount, the liquid level of the electric steam generator is continuously increased, and finally, the space in the electric steam generator is reduced or even disappears, so that the compensation steam generated by the electric steam generator is further reduced, and the sufficient heating steam cannot be provided for the electric steam heating chamber, thereby affecting the treatment effect of the system. The liquid level of the electric steam generator is kept unchanged by adjusting the output quantity of the steam condensate, and the problems can be effectively solved.
In addition, the preheating capacity of first pre-heater is fixed unchangeable, and it is equal with the indoor radioactive liquid waste's of first stoste volume to set up to the indoor steam condensate of first preheating usually, and first pre-heater can preheat the radioactive liquid waste to predetermineeing the temperature, consequently, this disclosure controls the output quantity of steam condensate, can also ensure the steady operation of first pre-heater, ensures that first pre-heater can preheat the radioactive liquid waste who gets into wherein to predetermineeing the temperature.
According to the present disclosure, the system may further include a feed tank 9, a purification tower 4, a hot water pump 10, and an external discharge pipe 8; the outlet of the feeding groove 9 is communicated with the inlet of the first raw liquid chamber; the purification tower 4 is arranged between the evaporation chamber and the vapor compressor 5, an inlet of the purification tower 4 is communicated with an outlet of the evaporation chamber, and an outlet of the purification tower 4 is communicated with an inlet of the vapor compressor 5; the hot water pump 10 is arranged between the electric steam generator 6 and the first preheating chamber, the inlet of the hot water pump 10 is communicated with the condensate outlet of the electric steam generator 6, and the outlet of the hot water pump 10 is communicated with the inlet of the first preheating chamber, so that the steam condensate in the electric steam generator 6 is fed into the first preheating chamber; the outer discharge pipe 8 is communicated with the outlet of the first preheating chamber.
According to the present disclosure, a first filter screen may be disposed at an outlet of the evaporation chamber, a second filter screen may be disposed in the purification tower 4, and the secondary steam from the evaporation chamber enters the vapor compressor 5 after passing through the first filter screen and the second filter screen.
The first filter screen and the second filter screen can effectively remove water drops which are carried in steam and do not reach the emission standard, and the water drops are prevented 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 of treating radioactive waste using the system of any of the above, which may include: 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; under the condition that 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 degree of the condensate flow regulating valve; and under the condition that the actual liquid level is higher than the preset liquid level, the controller is utilized to control the condensate flow regulating valve so as to increase the opening degree of the condensate flow regulating valve.
In the present disclosure, in particular, the opening degree of the condensate flow regulating valve may be automatically adjusted by a controller commonly used in the art, such as a programmable logic controller (PLC system). The reduction or increase of the opening of the condensate flow regulating valve can be determined according to actual needs, and details are not repeated in the disclosure.
According to the present disclosure, the preset liquid level may be 50 to 65%, preferably 55 to 60%, of the depth inside the electric steam generator. This is disclosed sets for the fixed value with the liquid level in the electric steam generator to liquid level change in the electric steam generator regulates and control steam condensate's output quantity, makes steam condensate's output quantity gradually equal to its backward flow volume, thereby makes the system operation tend to stable, and this can be under the condition of guaranteeing electric steam generator steady operation all the time, adjusts the performance and the operating stability of system, and this is favorable to the long-term steady operation of guarantee system.
According to the disclosure, when the opening degree of the condensate flow regulating valve is regulated, the regulating range can be 25-35% of the total opening degree of the condensate flow regulating valve.
Optionally, the method may further include: sequentially feeding radioactive waste liquid to be treated into a first raw liquid chamber of the first preheater and a second raw liquid chamber of the second preheater for preheating treatment; the preheated radioactive waste liquid enters an evaporation chamber of the evaporator for evaporation treatment to obtain secondary steam and concentrated waste liquid; the secondary steam enters the steam compressor to be pressurized and heated to obtain high-temperature steam, and the high-temperature steam is used as a heat source to return to a heating chamber of the evaporator for heat exchange; feeding 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 steam condensate generated by heat exchange in the heating chamber and 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 enter a heating chamber of the evaporator as a heat source for heat exchange; and part of steam condensate in the electric steam generator is used as a heat source to enter a first preheating chamber of the first preheater for heat exchange, and the steam condensate after heat exchange is discharged from an outlet of the first preheating chamber.
According to the present disclosure, the temperature of the radioactive waste liquid is raised to 70 to 85 ℃ after being preheated by the first preheater, and the temperature of the radioactive waste liquid is raised to 90 to 98 ℃ after being preheated by the second preheater.
According to the disclosure, after the pressurization and temperature rise treatment is performed by the steam compressor, the pressure of the high-temperature steam may be 50kPa to 80kPa, and the temperature may be 110 ℃ to 120 ℃.
According to the present disclosure, the temperature of the steam condensate entering the first preheating chamber from the electric steam generator may be 110 ℃ to 120 ℃; the temperature of the vapour condensate discharged from the outlet of the first preheating chamber may be between 40 ℃ and 55 ℃.
According to the present disclosure, the temperature of the compensation steam may be 110 ℃ to 120 ℃.
The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.
It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.
In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.