JP2014185892A - Dehumidification system in turbine condenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dehumidification system in a turbine condenser, not causing air leakage from a dehumidification device using a desiccant rotor for dehumidify air in the condenser and allowing stable dehumidification effect to be obtained without depending on air humidity change inside the condenser, in maintenance construction in the turbine condenser of a nuclear power plant.SOLUTION: The dehumidification system in the turbine condenser includes: an air suction port for sucking air in the condenser; an HEPA filter connected to the air suction port via a duct; a dehumidification device having a desiccant rotor connected to a subsequent stage of the HEPA filter; a blower fan connected to a subsequent stage of the dehumidification device; a reproduction heater having a duct connecting an exhaust side of the blower fan and an exhaust port installed in the condenser, and supplying heated air to a reproduction part of the desiccant rotor; and a reproduction fan for sucking exhaust air from the reproduction part of the desiccant rotor.

Description

  The present invention relates to a dehumidifying device for dehumidifying the inside of a turbine condenser of a nuclear power plant, and more particularly to a dehumidifying device using a desiccant rotor in which a hygroscopic agent is formed in a drum shape.

  As shown in FIG. 1, the flow of a general boiling water nuclear power plant is to generate power by a generator 50 by rotating a high-pressure turbine 20 and a low-pressure turbine 30 by steam generated in a pressure vessel 10. After the used steam is returned to water by the condenser 60, the steam is heated by the low-pressure feed water heater 110 and the high-pressure feed water heater 130 and returned to the pressure vessel 10. A heat exchange tube 80 for exchanging heat with seawater is installed in the condenser 60. For maintenance such as countermeasures against corrosion of the heat exchange tube 80, the condenser 60 is opened so that workers can There is a case to work inside.

  This operation is performed in a state where water is discharged from the condenser 60, but the humidity in the condenser 60 which has just been opened is as high as about 90%, and therefore the corrosion of the heat exchange tube 80 proceeds during the operation. In order to prevent this and to improve the working environment of workers, it is necessary to take dehumidification and countermeasures against radioactive dust.

  As countermeasures for dehumidification and radioactive dust in a similar environment, the air in the suppression chamber is sucked into Patent Document 1 and the air is accompanied by the repainting work for renewing the coating film in the pressure suppression chamber (in the suppression chamber). The structure which capture | acquires the dust to perform, dehumidifies the air after dust removal, and is supplied in a suppression chamber is disclosed. However, there is no specific description of the dehumidifier, and because of the push-in method in which the dehumidifier is arranged after the fan, air leakage may occur in the case of a device with a large pressure loss such as a desiccant rotor. There is.

  On the other hand, Patent Document 2 describes a dry-type dehumidifier that takes in air in a reactor building, dehumidifies it, and supplies it to the pressure suppression chamber (the desiccant rotor is also a kind thereof), and a discharge side and a suction side of the dehumidifier. A configuration is disclosed in which the amount of dehumidified air supplied into the pressure suppression chamber is controlled by adjusting the bypass line to be connected and the amount of dehumidified air circulated through the bypass line. Similar to the above document, the dehumidifying device is pushed in, and even air with little dust in the reactor building is not preferable because there is a risk of leakage.

JP 2000-314794 A JP 2004-226249 A

  It is an object of the present invention to provide a turbine condenser dehumidification system that does not cause air leakage from a dehumidifier using a desiccant rotor so as not to cause the problems described in Patent Documents 1 and 2 above. To do.

  Another object is to obtain a stable desiccant rotor dehumidifying effect regardless of the humidity change of the air in the condenser.

  In order to solve the above problems, a dehumidifying system in a turbine condenser according to the present invention includes an intake port for sucking air in the condenser, a HEPA filter connected to the intake port via a duct, and the HEPA A dehumidifying device having a desiccant rotor connected to the subsequent stage of the filter, a blower fan connected to the subsequent stage of the dehumidifying device, and a duct connecting the exhaust side of the blower fan and the exhaust port installed in the condenser And a regeneration heater for supplying heated air to the regeneration portion of the desiccant rotor, and a regeneration fan for sucking exhaust gas from the regeneration portion of the desiccant rotor. Thereby, since all the air flowing into the desiccant rotor is sucked, leakage of air from the desiccant rotor can be prevented.

  Further, the turbine condenser dehumidification system according to the present invention is connected to an intake port for sucking air in the condenser, a HEPA filter connected to the intake port via a duct, and a subsequent stage of the HEPA filter. A dehumidifying device having a desiccant rotor, a blower fan connected to a subsequent stage of the dehumidifying device, a duct connecting an exhaust side of the blower fan and an exhaust port installed in the condenser, and a regeneration unit of the desiccant rotor A regenerative heater for supplying heated air to the regenerator and a regenerative fan for sucking exhaust from the regenerative portion of the desiccant rotor, and measuring the differential pressure between the upstream side of the blower fan and the upstream side of the regenerative fan It has a differential pressure measuring instrument. As a result, the pressure on the upstream side of the blower fan can be kept negative from the upstream side of the regeneration fan, and the air in the turbine condenser is prevented from leaking from the regeneration fan through the inside of the desiccant rotor. it can.

  Further, the turbine condenser dehumidification system according to the present invention is connected to an intake port for sucking air in the condenser, a HEPA filter connected to the intake port via a duct, and a subsequent stage of the HEPA filter. A heater for air heating, a dehumidifying device having a desiccant rotor connected to the subsequent stage of the air heating heater, a blower fan connected to the subsequent stage of the dehumidifying device, an exhaust side of the blower fan, and installed in the condenser A duct for connecting the exhaust port, a regeneration heater for supplying heated air to the regeneration portion of the desiccant rotor, a regeneration fan for sucking exhaust gas from the regeneration portion of the desiccant rotor, It has a differential pressure measuring device for measuring a differential pressure between the upstream side and the upstream side of the regeneration fan. Thereby, even when the humidity in the turbine condenser changes, the humidity change can be reduced by the air heating heater, so that a stable desiccant rotor dehumidifying effect can be obtained.

  Further, the turbine condenser dehumidification system according to the present invention is connected to an intake port for sucking air in the condenser, a HEPA filter connected to the intake port via a duct, and a subsequent stage of the HEPA filter. A heater for air heating, a dehumidifying device having a desiccant rotor connected to a subsequent stage of the heater for air heating, a plurality of blower fans connected in parallel to a subsequent stage of the dehumidifying apparatus, an exhaust side of the plurality of blower fans, and the A duct connecting an exhaust port installed in the condenser, a regeneration heater for supplying heated air to the regeneration portion of the desiccant rotor, and a regeneration fan for sucking exhaust air from the regeneration portion of the desiccant rotor And a differential pressure measuring device for measuring a differential pressure between the upstream side of the blower fan and the upstream side of the regeneration fan. As a result, even when the pressure of the HEPA filter or the desiccant rotor increases due to dust in the turbine condenser, it is possible to obtain a constant amount of air flow by controlling the number of operating fans, so stable dehumidification of the desiccant rotor An effect can be obtained.

  According to the turbine condenser dehumidification system having the above-described features, the air in the turbine condenser can be dehumidified in a closed loop, so that the diffusion of radioactive substances into the building can be prevented. In addition, a stable desiccant rotor dehumidifying effect can be obtained even in a dehumidifying change in the turbine condenser due to a decrease in humidity due to operation of the dehumidifying device or a change in weather.

Schematic showing the flow of a boiling water nuclear power plant. Schematic which shows the structure of Example 1 of this invention. Schematic which shows the structure of Example 2 of this invention. Schematic which shows the structure of Example 3 of this invention. Schematic which shows the structure of Example 4 of this invention. The top view which shows arrangement | positioning of Example 4 of this invention.

FIG. 2 is a schematic diagram illustrating the configuration of the dehumidifying system in the turbine condenser according to the first embodiment of the present invention.
Dehumidification having an intake port 290 for sucking high-humidity air in the condenser 60, a HEPA filter 220 connected to the intake port 290 via a duct 300, and a desiccant rotor 240 connected to the subsequent stage of the HEPA filter 220 The desiccant rotor 240 has a device 210, a blower fan 250 connected to the subsequent stage of the dehumidifying device 210, a duct connecting the exhaust side of the blower fan 250 and the exhaust port 280 installed in the condenser. A regeneration heater 270 that supplies heated air to the regeneration unit 245 and a regeneration fan 260 that sucks exhaust air from the regeneration unit 245 of the desiccant rotor 240.

  After the condenser 60 is opened, the water in the turbine condenser 60 is discharged before the maintenance work, but the moisture in the condenser 60 is about 90% (temperature) because some moisture remains. 30 to 40 ° C.), and there is also radioactive dust in the condenser 60. Therefore, by passing the air in the condenser 60 through the system including the HEPA filter 220 and the dehumidifying device 210 to perform dehumidification and dust removal, the humidity is gradually reduced to about 25% and the dust concentration is also reduced. To improve the working environment. The desiccant rotor 240 is formed by adsorbing an adsorbent in a circular drum shape. The desiccant rotor 240 is divided by a seal structure into an adsorption part that adsorbs moisture in the air to produce dry air and a regeneration part that releases the adsorbed moisture by hot air. It is rotating at a slow speed of about 8 revolutions per hour.

  The seal structure has a slight gap between the rotating adsorbent and the blower fan so that the air returned into the condenser 60 by the blower fan 250 does not leak into the system discharged by the regeneration fan 260. The 250 side is maintained at a negative pressure.

  Although the HEPA filter 220 has a particle collection rate of 99.97% or more with respect to particles having a rated air volume and a particle size of 0.3 μm, particles that are not collected may adhere to the desiccant rotor 240. Therefore, when the regeneration heating air is pushed in, radioactive dust attached to the desiccant rotor 240 together with the heating air from the casing of the dehumidification device may leak to the periphery of the dehumidification device. Is desirable.

FIG. 3 is a schematic diagram showing the configuration of a turbine condenser dehumidification system according to Embodiment 2 of the present invention.
A dehumidifier 210 having an intake port 290 for sucking air in the condenser 60, a HEPA filter 220 connected to the intake port 290 via a duct 300, and a desiccant rotor 240 connected to a subsequent stage of the HEPA filter 220; The blower fan 250 connected to the subsequent stage of the dehumidifier 210, the duct connecting the exhaust side of the blower fan 250 and the exhaust port 280 installed in the condenser 60, and the regeneration unit 245 of the desiccant rotor 240 A regenerative heater 270 for supplying heated air to the regenerator, a regenerative fan 260 for sucking exhaust gas from the regenerator 245 of the desiccant rotor 240, and an upstream side of the blower fan 250 and an upstream side of the regenerative fan 260 The differential pressure measuring device 310 that measures the differential pressure is provided.

  A difference in configuration from the first embodiment is that a differential pressure measuring device 310 is provided. Although it is conceivable to previously set operating conditions using the air volume and pressure of the blower fan 250 and the regeneration fan 260 as parameters, the humidity of the air in the condenser 60 varies depending on various factors as described above. Therefore, it is effective to measure the differential pressure between the upstream side of the blower fan 250 and the upstream side of the regeneration fan 260 in real time to maintain the blower fan 250 side at a more negative pressure. Note that if the operating condition of the blower fan 250 is changed in order to maintain the negative pressure relationship between the two, the amount of dry air supplied into the condenser 60 changes, so the operating condition of the regeneration fan 260 is preferably changed. However, the operating conditions of the regeneration heater 270 are also adjusted accordingly.

FIG. 4 is a schematic diagram showing the configuration of a turbine condenser dehumidification system according to Embodiment 3 of the present invention.
An intake port 290 for sucking air in the condenser 60, a HEPA filter 220 connected to the intake port 290 via a duct 300, an air heater 230 connected to a subsequent stage of the HEPA filter 220, and the air A dehumidifier 210 having a desiccant rotor 240 connected to the rear stage of the heater 230, a blower fan 250 connected to the rear stage of the dehumidifier 210, the exhaust side of the blower fan 250, and the condenser 60 are installed. A duct connecting the exhaust port 280, a regeneration heater 270 for supplying heated air to the regeneration unit 245 of the desiccant rotor 240, and a regeneration fan 260 for sucking exhaust from the regeneration unit 245 of the desiccant rotor 240 are provided. In addition, a differential pressure measuring device 3 that measures a differential pressure between the upstream side of the blower fan 250 and the upstream side of the regeneration fan 260. And has a 0.

  The difference from the configuration of the second embodiment is that an air heating heater 230 is provided. Since the humidity of the air in the condenser 60 changes as described above, the desiccant rotor 240 (for example, about 8 revolutions per hour), the regeneration heater 270 (for example, the amount of heat), and the regeneration fan 260 ( For example, it is necessary to change the operating conditions of the equipment, such as the flow rate, but it is desirable to keep the respective operating efficiency constant around the rated value with high operating efficiency. For this purpose, it is effective to keep the humidity of the air flowing into the dehumidifying device 210 constant, and the air heating heater 230 controls the humidity of the air in the condenser 60 so as not to fluctuate greatly, so that the entire dehumidifying system is The driving efficiency is improved.

FIG. 5 is a schematic diagram showing a configuration of a dehumidifying system in a turbine condenser according to a fourth embodiment of the present invention.
An intake port 290 for sucking air in the condenser 60, a HEPA filter 220 connected to the intake port 290 via a duct 300, an air heater 230 connected to a subsequent stage of the HEPA filter 220, and the air A dehumidifier 210 having a desiccant rotor 240 connected to the rear stage of the heater 230, a plurality of blower fans 250 connected in parallel to the rear stage of the dehumidifier 210, the exhaust side of the plurality of blower fans 250 and the condensate A duct connecting the exhaust port 280 installed in the chamber 60, a regeneration heater 270 for supplying heated air to the regeneration unit 245 of the desiccant rotor 240, and exhaust from the regeneration unit 245 of the desiccant rotor 240 While having a regeneration fan 260, the differential pressure between the upstream side of the blower fan 250 and the upstream side of the regeneration fan 260 is measured. And a differential pressure measuring instrument 310.

  The difference from the third embodiment is that a plurality of blower fans 250 are connected in parallel. As described above, when the air heater 230 is controlled according to the humidity in the condenser 60, the fluctuation in humidity can be reduced, but the air volume changes with the temperature of the air. Further, the air volume decreases as the operating time increases due to an increase in pressure loss due to the influence of dust collection by the HEPA filter 220. Therefore, although it is necessary to change the air volume (output) of the blower fan 250, the efficiency of the entire system can be improved by operating the blower fan 250 in parallel because the blower fan 250 may deviate from the rated operation condition and the operation efficiency may decrease. Improvement has been achieved.

  FIG. 6 shows a planar arrangement of the dehumidifying system in the turbine condenser when the fourth embodiment is performed, and the arrangement is the same as the number of low-pressure turbines (condensers). The size of the condenser 60 is several tens of meters in length and width, and the intake port 290 and the exhaust port 280 are arranged on a diagonal line in order to efficiently dehumidify the air in this space. Further, since the path from the inlet 290 to the HEPA filter 220 contains radioactive dust, it is preferable to shorten this path as much as possible. Therefore, the intake port 290 is disposed near a place where the dehumidifier 210 and the like are disposed, and the exhaust port 280 is disposed on the diagonal line (a position far from the dehumidifier 210). Note that exhaust from the regeneration fan 260 is in the vicinity of an air inlet (not shown) of the ventilation system of the building itself, so that moisture containing a large amount of moisture can be prevented from remaining in the building.

10 ......... pressure vessel, 20 ......... high pressure turbine, 30 ......... low pressure turbine, 40 ......... low pressure turbine, 50 ......... generator, 60 ......... condenser, 70 ......... circulation pump, 80 ......... Heat exchange tube, 90 ......... Water supply piping, 95 ......... Drain piping, 100 ......... Condensate pump, 110 ......... Low pressure feed water heater, 120 ......... Water supply pump, 130 ......... High pressure feed water heater, 200 ......... Fuel rod, 210 ......... Dehumidifier, 220 ......... HEPA filter, 230 ...... Heater for air heating, 240 ......... Desicant rotor, 245 ......... Regeneration unit, 250 ......... Blower fan, 260 ......... Regeneration fan, 270 ......... Regeneration heater, 280 ...... Exhaust port, 290 ...... Intake port, 300 ...... Duct, 310 ...... Differential pressure measuring instrument .

Claims (4)

An intake port for sucking air in a turbine condenser of a nuclear power plant, a HEPA filter connected to the intake port via a duct, a dehumidifying device having a desiccant rotor connected to a subsequent stage of the HEPA filter, and the dehumidification device A regenerative fan for supplying heated air to the regeneration section of the desiccant rotor, having a blower fan connected to the rear stage of the device, a duct connecting the exhaust side of the blower fan and an exhaust port installed in the condenser A dehumidifying system in a turbine condenser having a heater and a regeneration fan for sucking exhaust gas from a regeneration part of the desiccant rotor. The dehumidifying system in a turbine condenser according to claim 1, further comprising a differential pressure measuring device that measures a differential pressure between the upstream side of the blower fan and the upstream side of the regeneration fan. The turbine condenser dehumidification system according to claim 1 or 2, wherein an air heating heater is provided between the HEPA filter and the dehumidifier. The dehumidification system in a turbine condenser according to any one of claims 1 to 3, wherein a plurality of the blower fans are connected in parallel.

Images