JPH0132900B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ventilation and air conditioning method for an electrical equipment room, and particularly to a ventilation and air conditioning method suitable for a ventilation and air conditioning system in a central control room of a nuclear power plant.

FIG. 1 is a schematic system diagram of a conventional nuclear power plant central control room ventilation air conditioning system. During normal operation of the plant, outside air is taken in through the air supply louver 1 approximately 0.5 times/h (the unit of ventilation rate is 1 time/h when the room volume of air is ventilated in 1 hour).
). The outside air taken in enters the recirculating air conditioner 3 via the damper 2, where it is purified, heated or cooled, and is supplied by the blower 4 via the electric coil 15 to the central control room 5. The air discharged from the central control room 5 is discharged to the outside of the building from the exhaust louver 9 via the damper 8 by the exhaust fan 7 in an amount equal to the amount of outside air taken in, and the remaining air is passed through the recirculation line 6 to the recirculation air conditioner 3. It returns to the front and is recirculated. The amount of air to be recirculated is determined to be the amount of air necessary to remove the heat load generated by equipment and operators installed in the central control room 5,
Usually about 10 times/h. However, since computers and other equipment are installed in the central control room 5, the room temperature must be maintained at about 21 to 26°C. Furthermore, since the heat load from the installed equipment is extremely large, the refrigerator 12 connected to the cooling coil 10 of the recirculation air conditioner 3 via the cold water circulation pump 11 must be operated according to the outside air temperature. That is, the cooling coil 10 of the recirculation air conditioner 3 cools the air taken in and controls the temperature within the central control room 5. Note that an emergency filter train 13 and an emergency recirculation blower 14 are connected in front of the recirculation air conditioner 3.

When the temperature of the central control room 5 is 26℃ during normal plant operation, the difference between the air blowing temperature and the room temperature is 10℃.
When estimated, the supply air temperature will be 14°C, taking into account the heat-up of about 2°C by the blower 4.
However, in conventional devices employing the recirculation air conditioning system as described above, the temperature of the air returned through the recirculation line 6 is as high as 26° C. (design room temperature). For this reason, the temperature immediately before the cooling coil 10 is, for example, if the recirculation air volume is 9.5 times/h and the outside air intake amount is 0.5 times/h, the outside air temperature is -
Even if the temperature was 5°C, the supply air temperature would be 24.5°C. This exceeds the above-mentioned supply air temperature condition of 14°C, and therefore the refrigerator 12 must be operated to lower the supply air temperature. By the way, the value of the outside air temperature of -5° C. is approximately the same as the outside air condition in winter. Therefore, the conventional ventilation air conditioning method cannot utilize low-temperature outside air, and the refrigerator 12 must be operated throughout the year, resulting in high running costs.
Furthermore, when the outside air temperature decreases, the indoor heat load becomes relatively small compared to the summer, so the refrigerator 12 operates at a low load, so the operation control of the refrigerator 12 during this low load operation is complicated. It also had the disadvantage of becoming.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for ventilation and air conditioning of an electrical equipment room that eliminates the above-mentioned drawbacks and is energy-saving and has low running costs.

The present invention provides a ventilation air conditioner with a once-through air conditioning system and a recirculation air conditioning system, and by switching between these systems at the appropriate time, the amount of outside air intake is adjusted to the recirculation air volume during periods when the outside air temperature is lower than the supply air temperature condition. The above objective will be achieved by switching to a once-through air conditioning system that is equivalent to the above.

An embodiment of the present invention will be described below with reference to the drawings, using the same reference numerals for the same parts as in the conventional example.

FIG. 2 is an example of a ventilation air conditioning system to which an embodiment of the ventilation air conditioning method for an electrical room of the present invention is applied. The air supply louver 1 is connected via a damper 2 to a recirculation air conditioner 3 by piping. This recirculation air conditioner 3
is connected to the central control room 5 by piping via a blower 4 and an electric coil 15. The central control room 5 is connected to an exhaust louver 9 via a damper 16, an exhaust fan 17, and a damper 8 by piping. Further, the pipe on the exhaust side of the central control room 5 is connected to a pipe section in front of the recirculation air conditioner 3 via a damper 18 of the recirculation line 6. Cooling coil 1 of recirculation air conditioner 3
0 is connected to a refrigerator 12 via a cold water circulation pump 11. Further, an emergency filter train 13 and an emergency recirculation blower 14 are connected to the piping in front of the recirculation air conditioner 3. Further, a bypass circuit having a damper 19 and an exhaust fan 7 is provided in a piping section connecting the central control room 5 and the exhaust louver 9. Reference numeral 20 denotes a temperature sensor that detects the outside air temperature, and the output signal of this temperature sensor 20 is transmitted to dampers 16, 18, 19 and exhaust fans 7, 17, which are equipped with a control drive mechanism that is operated based on this output signal.
It is input to the refrigerator 12 and the cold water circulation pump 11.

Next, the operation of the ventilation air conditioner shown in FIG. 2 will be explained. This ventilation air conditioning system is equipped with a damper 18 for closing the recirculation line 6 and an exhaust fan 17 for exhaust air in order to enable a once-through air conditioning system in addition to the conventional recirculation air conditioning system. It is becoming.

During normal plant operation, during periods when the outside air temperature is higher than the air supply temperature condition to the central control room 5 (about 14°C as an example), the chiller 12 is operated using the recirculation air conditioning method as before. Cool the supply air. That is, outside air is taken in at a rate of 0.5 times/h through the air supply louver 1, filtered by the recirculation air conditioner 3,
After cooling the supply air to the supply air temperature condition with the chilled water cooling coil 10 by operating the refrigerator 12,
Air is supplied into the central control room 5. The air discharged from the central control room 5 is exhausted from the exhaust louver 9 to the outside of the building through the exhaust fan 7 in the amount of outside air intake (0.5 times/h) according to the flow balance. At this time, the damper 16 is closed because the exhaust fan 17 for the once-through air conditioning system is not used. The remaining air volume (9.5 times/h) is recirculated through the recirculation line 6.

For periods when the outside air temperature is lower than the supply air temperature condition of the central control room 5, the recirculation line 6 is connected to the damper 18.
All air required for heat load removal is taken in from the outside air, and with the refrigerator 12 stopped, the outside air is directly supplied to the central control room 5 by the blower 4 without being cooled. After the heat load in the room 5 is removed, all the air is exhausted to the outside of the building from the exhaust louver 9 using the once-through air conditioning type exhaust fan 17. In this case, damper 19 is closed.

During the period when this once-through air conditioning method is adopted, for example, in the middle of winter, the outside air temperature may be extremely lower than the supply air temperature, and if air conditioning is performed once-through, the indoor temperature may not be maintained at the designed temperature. In such a case, the air supplied to the central control room 5 is heated by the electric coil 15, the supply air temperature is adjusted, and then the air is supplied into the central control room 5 to maintain the designed temperature.

In addition, both the recirculation air conditioning method and the once-through air conditioning method reduce the temperature inside the central control room 5 to approximately 21°C.
For micro-investigation at ~26°C, the electric coil 1
This is done by heating the supply air using 5.

The amount of outside air taken in by switching between the recirculation air conditioning system and the once-through air conditioning system is adjusted by adjusting the degree of restriction of the dampers 2 and 8 and opening and closing of the damper 18.
Further, the exhaust amount is determined by switching between the exhaust fans 7 and 17.

Both of the above switching control methods are based on temperature sensor 2.
This method detects the outside air temperature by installing a control drive mechanism that switches between zero and temperature, and automatically switches between the recirculation air conditioning system and the once-through air conditioning system depending on the outside air temperature.

To switch between the above two types, the outside air temperature at the time of switching between the two types is set in advance, and the control drive mechanism that works with the temperature sensor 20 is activated based on the outside air temperature detected by the temperature sensor 20 and the set outside air temperature at that time. Dampers 16, 18, 19, air distributors 7, 17, refrigerator 12, cold water circulation pump 11
be controlled.

If the outside temperature is below the set outside temperature, the once-through air conditioning method will be used as the ventilation method. For this reason, the dampers 18 and 19 are automatically closed and the exhaust fan 7 is stopped by the control drive mechanism which is switched in response to the detection by the temperature sensor 20. Further, the refrigerator 12 and the cold water circulation pump 11 are also controlled to automatically stop. On the other hand, the damper 16 and the exhaust fan 17 are automatically opened and operation is started.
If the outside air temperature rises above the set outside air temperature, the central control room 5
Since the internal temperature cannot be controlled, the dampers 18 and 19 are automatically opened according to the outside temperature detected by the temperature sensor 20.
The exhaust fan 7 is operated. At this time, on the contrary, damper 1
6 and the exhaust fan 17 are automatically stopped, and the central control room 5
The air conditioning system will be switched to recirculation air conditioning system. Furthermore, since the refrigerator 12 and the cold water circulation pump 11 are started at the same time, the central control room 5 can be easily controlled to the designed temperature.

According to this embodiment, if the outside air temperature is below the upper limit of the supply air temperature condition to the central control room 5, it is possible to switch to the once-through air conditioning system, and therefore the amount of outside air intake is reduced from the conventional recirculation. This is approximately 20 times more efficient than with air conditioning, and since the supply air is not recirculated, high-temperature air is not supplied, making the natural cooling medium of outside air more effective. This has the effect of sufficiently removing the heat load generated within the central control room 5. Therefore, during the period that can be covered by the once-through air conditioning system, there is no need to operate the refrigerator 12, which makes it possible to save energy and significantly reduce the running cost of the ventilation air conditioning system. . For example, at a certain Planu site, the effect is that the refrigerator 12 can be shut down for five months.

In addition, by detecting changes in the outside air temperature using the temperature sensor 20, it is possible to automatically switch between the two ventilation systems, which prevents malfunctions that would otherwise occur when operated by a human. This has the effect of improving plant reliability.

Furthermore, in the past, a smoke exhaust fan was sometimes installed in the central control room 5 to exhaust smoke in the event of a fire, but according to this embodiment, a once-through air conditioning system is used in the event of a fire, and the amount of outside air intake is reduced. By maximizing the smoke exhaust air volume, it is possible to fully satisfy the smoke exhaust air volume stipulated by the Building Standards Act, which not only eliminates the need to install an exhaust fan for smoke exhaust, but also provides a sufficient smoke exhaust effect. be able to.

FIG. 3 shows another embodiment of the invention. The difference between this embodiment and the previous embodiment lies in the ventilation method when the outside air temperature falls below the supply air temperature. For this reason, in this embodiment, a movable valve 21 is inserted in place of the damper in the piping section in front of the recirculation air conditioner 3, and a movable valve 22 is inserted between the exhaust fan 17 and the exhaust louver 9. . Further, the damper 19 and the exhaust fan 7 provided in the previous embodiment are omitted, and the other configurations are the same as in the previous embodiment.

During the period when the outside air temperature is higher than the supply air temperature condition, the recirculation air conditioning method is used as in the previous embodiment. but,
During periods when the outside air temperature is lower than the supply air temperature condition, the temperature sensor 20 detects the outside air temperature and automatically adjusts the opening degrees of the movable valves 21 and 22 to adjust the ratio between the recirculation air volume and the outside air intake amount. to optimally control supply air temperature. Therefore, this embodiment uses a recirculation air conditioning system with a variable outside air intake volume that removes the heat load generated in the central control room 5 by using outside air taken in at an appropriate rate while the refrigerator 12 is stopped. It is an air conditioning system that combines through air conditioning system.

According to this embodiment, during the period when the outside air temperature is lower than the air supply condition, the outside air can be heated by using the heat source of the recirculated air volume, and the amount of heating by the electric coil 15 is significantly reduced. It has the effect of saving energy. That is, according to this embodiment, in addition to the effects obtained in the previous embodiment, the energy saving of the electric coil 15 is added, and the running cost of the ventilation air conditioner is further reduced.

FIG. 4 shows still another embodiment of the present invention. The feature of this embodiment is that compared to the previous embodiment, the exhaust method is different when switching to the recirculation air conditioning system. In other words, when switching to the recirculation air conditioning system, the exhaust fan 17 used in the once-through air conditioning system
cannot be used even if the air volume is reduced because the air volume is more than 20 times different. Therefore, in this embodiment, instead of providing an exhaust fan for the recirculation air conditioning system, exhaust is performed by utilizing natural ventilation from the central control room 5 as indicated by arrow A in the figure.

According to this embodiment, when switching to the recirculation air conditioning system, there is no need to install a separate exhaust fan, which is particularly effective in keeping equipment costs low, and it also reduces the space required to install an extra exhaust fan. There are benefits to be gained.

FIG. 5 shows still another embodiment of the present invention. This embodiment differs from the embodiments shown in FIGS. 2 and 4 in that an exhaust louver 23 is installed in the central control room instead of providing an exhaust fan for the recirculation air conditioning system.

According to this embodiment, when switching to the recirculation air conditioning method, since the indoor air 5 is maintained at a positive pressure,
Opening the exhaust louver 23 has the effect of easily securing the exhaust air volume, and has the same effect as the embodiment shown in FIG. 4.

FIG. 6 shows still another embodiment of the present invention. In this embodiment, a service building ventilation air conditioning system of a nuclear power plant is equipped with both a recirculation air conditioning system and a once-through air conditioning system, which can be switched. The outside air drawn in from the supply air louver 24 passes through the damper 25 and enters the recirculation air conditioner 26 .
The air passing through this recirculation air conditioner 26 is sent to a blower 27.
Air is supplied to each of the clean area 28 and dirty area 29. The air from the clean area 28 is discharged from the exhaust louver 3 through a damper 30 and an exhaust fan 31.
2, or it passes through a recirculation line 33 and returns to the front of the recirculation air conditioner 26 via a damper 34. Further, the exhaust air from the dirty area is all sent to Stax S via an exhaust treatment device 35 and an exhaust fan 36. Chilled water is supplied to the recirculation air conditioner 26 by a cold water circulation pump 37, and this cold water is supplied to the refrigerator 3.
8.

The service building ventilation and air conditioning system has a relatively similar system configuration to the central control room ventilation and air conditioning system. The difference is that rooms with air that can be contaminated with radioactivity (Dirty Area 2)
9) and a room (clean area 28) containing air that is unlikely to be contaminated, all the air supplied to the dirty area 29 is discharged to the stack S. However, the clean area 28 uses a recirculation air conditioning system that partially takes in outside air. In this embodiment, the present invention is applied to the clean area 28. For this reason, in the past, the exhaust gas from the clean area 28 was transferred to the dirty area 29 or recirculated, so that almost no exhaust air was released outside the building. However, in this embodiment, by providing an exhaust fan 31 and switching dampers 30 and 34, clean air can be directly exhausted from the exhaust louver 32.

According to this embodiment, like the central control room ventilation air conditioning system, the clean area 28 of the service building can be operated by switching between the once-through air conditioning system and the recirculation air conditioning system, so the service building ventilation This has the effect of reducing the running cost of the air conditioning system refrigerator 38 and also has the effect of saving energy.

As described above, according to the ventilation and air conditioning method for an electrical equipment room of the present invention, it is possible to save energy and reduce running costs.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a conventional central control room ventilation air conditioner, Fig. 2 is a system diagram of a central control room ventilation air conditioner to which an embodiment of the electrical room ventilation air conditioning method of the present invention is applied, and Fig. 3 is a system diagram of a central control room ventilation air conditioner to which another embodiment of the present invention is applied, FIG. 4 is a system diagram of a central control room ventilation air conditioner to which still another embodiment of the present invention is applied, and FIG. FIG. 6 is a system diagram of a ventilation air conditioner for a central control room to which still another embodiment of the present invention is applied. FIG. 6 is a system diagram of a ventilation air conditioner for a service building to which still another embodiment of the present invention is applied. 1...Air supply louver, 3...Recirculation air conditioner, 5...
...Main control room, 6...Recirculation line, 7,17...
...Exhaust fan, 9,23...Exhaust louver, 10...Cooling coil, 12...Freezer, 15...Electric coil, 16,18,19...Damper, 21,22...
...Movable valve.

Claims (1)

[Scope of Claims] 1. In a ventilation air conditioner that maintains an electrical equipment room at a set temperature throughout the year, after supplying air at a predetermined temperature to the electrical equipment room, most of the discharged air is brought back to the predetermined temperature. A recirculation air conditioner that supplies the electrical equipment room and a once-through air conditioner that supplies outside air to the electrical equipment room and exhausts all exhaust air from the electrical equipment room to the outside of the building are installed together, and both air conditioning equipment can be switched at appropriate times. A ventilation air conditioning method characterized in that it is used in 2. A device that detects the temperature of outside air, and by interlocking with this device, controls the on/off of dampers, exhaust fans, refrigerators, etc., and automatically operates the recirculation air conditioner and the once-through air conditioner. 2. The ventilation air conditioning method according to claim 1, further comprising a control drive device for switching. 3. In a ventilation air conditioner that maintains an electrical room at a set temperature throughout the year, the ventilation air conditioner is a recirculation air conditioner equipped with a movable valve that significantly changes the supply ratio between outside air and recirculated exhaust air. An electrical equipment room that is both a device and a once-through air conditioner, and that supplies air at a predetermined temperature to the electrical equipment room by changing the mixing ratio of outside air and recirculated exhaust air. Ventilation air conditioning method.