JPH0236198B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to ventilation and air conditioning equipment, and particularly to ventilation and air conditioning equipment for a central control room of a nuclear power plant. The central control room of a nuclear power plant is equipped with ventilation and air conditioning equipment to maintain a constant temperature at all times, both during normal times when the heat generation load is low to maintain functionality, and during emergencies when the heat generation load is large. FIG. 1 shows an example of a central control room ventilation air conditioning system according to the prior art. Normally, outside air is taken in through the outside air intake louver 1, combined with return air from the central control room 8, and sent to the air conditioner 4. Here, the air is cooled to a constant temperature by the cooling coil 5, heated by the heating coil 22 to maintain the central control room 8 at a required temperature, and then supplied to the central control room 8 by the fan 7. A part of the exhaust air from the central control room 8 is sent to the fan 1.
0 is directly discharged to the outside air, but the rest is returned to the air conditioner 4 through the duct 16 and reused. The outlet air temperature of the cooling coil 5 is controlled by adjusting the opening degree of the valve 15 by the temperature controller 24 and changing the amount of cold water, and is controlled by the circulation pump 13 between the cold water cooling coil 5 and the air-cooled refrigerator 12. Air is supplied to the central control room 8 by adjusting the opening degree of the valve 23 using the temperature controller 18 and changing the amount of steam supplied to the heating coil 22. In addition, in case of an emergency, an emergency filter 20 is installed to protect operators in the central control room 8 from radiation exposure.
and driving Juan 21. In this case, valve 2,
3 and 9 are closed, valves 19 and 6 are opened to shut off outside air, and a recirculation operation is performed through the emergency filter 20. According to conventional technology, the partial load control capacity of an air-cooled refrigerator is preferably about 30% or more of the maximum load, and if it is less than this, the refrigerator will repeatedly start and stop, which may cause failure, so However, a dummy load was applied to the refrigerator. For this reason, in the air conditioner, heating is performed after cooling, which is not desirable in terms of energy saving. An object of the present invention is to implement energy saving measures by controlling the number of refrigerators in operation based on outside air temperature and centrally controlled indoor temperature. The present invention provides an air conditioner having an outside air intake, a cooling coil that cools the outside air that flows in from the outside air intake, a conduit that guides the outside air that has passed through the air conditioner to a central control room, and an air conditioner that includes an inside of the cooling coil. In a ventilation air conditioning system for a central control room of a nuclear power plant, the main control room ventilation air conditioning system has a plurality of refrigerators that supply coolant to the air conditioner, and an emergency filter that purifies the outside air that flows in from the outside air intake in an emergency and supplies it to the air conditioner. , the temperature range of the outside air that can be controlled by a certain number of the refrigerators and the temperature range of the outside air that can be controlled by the partial number of the refrigerators and another number of the refrigerators are partially overlapped. and means for controlling the number of operating refrigerators based on the temperature of the outside air; and means for adjusting the flow rate of the coolant supplied from the refrigerator to the refrigeration coil based on the temperature in the central control room. A central control room ventilation air conditioning system for a nuclear power plant characterized by having a refrigerator which has been in operation up to now before the temperature of the outside air changes in the partially overlapped outside air temperature range. The system is used for air conditioning operation to reduce the frequency of switching the number of operating units. An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. The control characteristics in this embodiment are shown in FIG. 2 in terms of the relationship between the outside air temperature and the change in the heat generation load of the central control room, and the relationship between the refrigerating capacity of the ventilation air conditioning equipment refrigerator and the load control width. In the figure, A indicates the load control width when one refrigerator is operated, and B indicates the load control width when two refrigerators are operated. Also, band C shows the width of heat generation load change in normal times, and band D shows the width of heat generation load change in emergency times. From the two bands, a normal operation range E for two refrigerators, an operation range F for one refrigerator, and a range G in which both are possible are determined. The relationship between the number of refrigerators in operation and the outside temperature range in normal and emergency situations is summarized as follows from Figure 2.

[Table] From the above, the number of chillers in operation is 2 in an emergency, and 2 -> 1 when the outside temperature is below 5°C, and 1 -> 2 when the outside temperature is above 20°C. The daily outside temperature change range in Japan is approximately 10℃.
(According to "Science Chronology" - compiled by Tokyo Astronomical Observatory), the temperature range for changing the number of operating refrigerators is smaller than about 15 degrees Celsius, so if the operation of the refrigerators is controlled by the outside temperature, the frequency of switching the number of refrigerators will be very low. You can expect good driving. In FIG. 3, under normal conditions, outside air is taken in through the outside air intake louver 1, combined with return air from the central control room 8, and sent to the air conditioner 4. Here, the air is changed to a predetermined temperature by the cooling coil 5 (humidified if necessary), and is supplied to the central control room 8 by the fan 7. Four parts of the exhaust air from the central control room 8 is directly discharged to the outside air by the fan 10, while the remaining part is returned to the air conditioner 4 via the duct 16 and is reused. The room temperature inside the central control room 8 is controlled by adjusting the opening degree of the valve 15 using the temperature controller 18, changing the amount of cold water supplied to the cooling coil 5, and adjusting the supply air temperature. Circulation of cold water between the cooling coil 5 and the refrigerator 12 is performed by a pump 13. A surge tank 14 is provided in the cold water line to absorb changes in volume due to changes in the temperature of the cold water. The number of air-cooled refrigerators 12 in operation is controlled by detecting the outside air temperature using the temperature switch 17 and, based on the control characteristics shown in FIG. ,
Two units will be operated when the outside temperature is 20℃ or higher. In an emergency, the emergency filter 20 and fan 21 are operated to protect operators in the central control room 8 from radiation exposure, but because the heat input from the fan is large, two air-cooled refrigerators 12 are operated. Become. In this case, valves 2, 3, and 9 are closed, and valves 19 and 6 are opened to shut off outside air, resulting in a recirculation operation through the emergency filter 20. According to this embodiment, the number of operating chillers can be automatically controlled according to changes in heat generation load due to changes in outside air temperature, and there is no need for dummy loads even at low loads, so air cooling and regeneration using conventional technology are possible. Wasteful energy consumption such as heating can be eliminated. According to the present invention, (1) the number of operating chillers can be selected according to the heat generation load due to changes in outside air temperature, so abnormal start and stop of the chillers can be prevented, the failure potential is greatly reduced, and reliability is improved. I can figure it out. (2) Room temperature control in the central control room is performed by a control system based on chiller load control, which eliminates the need for reheating after cooling, which was required in the past, resulting in a significant energy saving effect.

[Brief explanation of drawings]

Fig. 1 is a schematic system diagram of a central control room ventilation air conditioning system showing an example of the prior art, and Fig. 2 is a diagram for explaining the prior art and the present invention, showing changes in outside air temperature and heat generation in the central control room. FIG. 3 is a schematic system diagram of a central control room ventilation air conditioning system showing an embodiment of the present invention. 1... Outside air intake louver, 2, 3, 6, 9, 1
5,19,23...Valve, 4...Air conditioner, 5...
...Cooling coil, 7, 10, 21...Fan, 8...
... Central control room, 11 ... Exhaust louver, 12 ... Air-cooled refrigerator, 13 ... Pump, 14 ... Surge tank, 16 ... Duct, 17 ... Temperature switch,
18, 24...Temperature controller, 20...Emergency filter, 22...Heating coil.

Claims (1)

[Claims] 1. An air conditioner having an outside air intake, a cooling coil that cools the outside air that flows in from the outside air intake, a conduit that guides the outside air that has passed through the air conditioner to a central control room, and a coolant in the cooling coil. In the central control room ventilation and air conditioning equipment of a nuclear power plant, the central control room ventilation air conditioning equipment includes a plurality of refrigerators that supply the outside air, and an emergency filter that purifies outside air that flows in from the outside air intake port and supplies it to the air conditioner in an emergency. It has a control characteristic that partially overlaps the temperature range of the outside air whose temperature can be controlled by a certain number of refrigerators, and the temperature range of the outside air whose temperature can be controlled by a certain number of refrigerators and another number of the refrigerators, A means for controlling the number of operating refrigerators based on the temperature of the outside air, and a means for adjusting a flow rate of the coolant supplied from the refrigerator to the refrigeration coil based on the temperature in the central control room. Ventilation and air conditioning equipment for the central control room of a nuclear power plant.