JP6431356B2 - Method and apparatus for supplying cooling water for cooling tower of oil-feed water-cooled transformer - Google Patents

Description

  The present invention relates to a method and an apparatus for supplying cooling water for a cooling tower of an oil-feed water-cooled transformer. More specifically, the present invention relates to a cooling tower cooling water supply method and apparatus that can be adopted to cool a large-capacity transformer in, for example, an ultrahigh voltage substation.

  In the cooling method of circulating cooling water, the cooling fluid whose temperature is increased by cooling the fluid to be cooled is usually used by circulating a part of the cooling water by evaporating a part of it in the cooling tower and lowering the temperature of the remaining cooling water by latent heat of vaporization. Is.

  Specifically, this cooling method is widely used, for example, for cooling equipment such as transformers in substations, cooling condensers such as compression chillers, and cooling absorbers and condensers of absorption chillers. ing.

  By the way, in recent years, in the city center, it has become difficult to increase the capacity and secure the installation location due to the increase in power demand, so there is a strong demand for downsizing, and transformers are installed in the basement of buildings, etc. There are an increasing number of examples.

  For example, when a large-capacity transformer used in an ultra-high voltage substation is installed in the basement of a building or the like, the heat generated in the transformer structure is transferred to a cooling medium that cools the transformer. At the same time, it is transmitted to the cooling water through a water-cooled cooler, and this cooling water is pumped up to a cooling tower installed on the roof of the building by a pump, and a part of the cooling water is evaporated in the cooling tower. The structure which returns to the water cooling type | mold cooler of a transformer is mainly employ | adopted after cooling (refer patent documents 1-6).

  In order to compensate for the amount of evaporating water as described above, city water is replenished, but this replenishing water contains inorganic ions such as calcium and silica components, etc. The concentration of inorganic ions, silica, etc. in the remaining water gradually increases, and when it is concentrated above a certain limit, it is deposited as a scale component in the piping or heat exchange part, resulting in a decrease in cooling efficiency due to deterioration of heat transfer or clogging of the piping. Cause.

  In order to prevent this, the conductivity of the cooling water in the cooling tower is measured, and when it is higher than the predetermined conductivity, the cooling water in use is drained and new cooling water is replenished. If this new cooling water is supplied with low conductivity, the cooling water exchange interval with gradually increasing conductivity can be lengthened, but the amount of water used increases. Moreover, since the said cooling water will be used over a long period of time when the cooling water with too low electrical conductivity is used, algae generate | occur | produces in cooling water. Occurrence of vagueness is not preferable in operation.

  For this reason, the optimum water quality of the replenishing cooling water is obtained based on the evaporation amount and the drainage amount of the cooling water and supplied. In order to obtain such cooling water, first, a method of changing the water quality by using a chemical is conceivable. However, in a cooling tower having a large amount of cooling water for cooling a transformer, chemical treatment is performed. This is avoided for cost and environmental reasons. Therefore, conventionally, this predetermined amount of cooling water is obtained by subjecting raw water such as tap water (city water) and groundwater to physical filtration with an ultrafiltration membrane (UF membrane) and then using a reverse osmosis membrane (RO membrane). It is formed by removing ions (see Patent Documents 3 and 4).

  If the conductivity of the cooling water can be lowered using the RO membrane permeated water as described above, the concentration factor can be increased, and the amount of water used and the amount of drainage can be reduced. Here, when RO membrane permeated water is used as cooling water, the processing capacity of the RO device has a certain limit, so the cooling water that has passed through the RO device has its conductivity measured by the conductivity measuring device, It is mixed with tap water to a specified conductivity and stored in a matte water tank. The cooling water stored in the mat water tank is appropriately supplied to the cooling tower when the water level in the cooling tower decreases or when the conductivity of the cooling water increases.

  The amount of water supplied by the water quality improvement device such as the RO device and the capacity of the mat water tank are calculated and determined from the amount of water used in the cooling tower of the substation. It is said that.

International Publication No. 98/01871 JP-A-10-223442 JP 2008-218679 A JP 2002-310595 A JP 2003-130587 A JP 2011-200039 A

  However, the amount of water supplied by a water quality improvement device such as an RO device is, for example, when a transformer is added and the amount of water used increases, the heat becomes extremely hot and the amount of water used temporarily increases from the average. If the amount of water is insufficient due to peak load because it is the cumulative total of the month, if the supply of raw water to the device is insufficient and the device cannot move as designed, the quality of the raw water is poor and the actual amount of water is less than the design water amount of the device In some cases, a shortage may occur when the device is temporarily stopped due to failure or inspection.

  Once the amount of water in the mat aquarium decreases in this way and once falls below the specified lower limit water level, as an emergency measure, the raw water supply valve to the mat aquarium opens and a large amount of water in the mat aquarium Since the raw water is supplied, the conductivity of the cooling water in the mat water tank is increased.

  Once the conductivity of the cooling water in the mat water tank rises due to the introduction of a large amount of raw water, the cooling water concentration factor decreases, the amount of water used in the cooling tower increases, and the amount of water stored in the mat water tank decreases, making up for this. Therefore, it will fall into the negative spiral that raw water is further supplied. And if it becomes such a negative spiral, the amount of water used will increase and the water-saving effect by reverse osmosis membrane introduction will fade.

  For this reason, the amount of water supplied by the water quality improvement device and the volume of the mat tank are taken into consideration from the beginning by introducing large equipment for future expansion of the substation, and taking into account the time and heat generation in overload operation. Naturally, it is also considered to increase the size of the equipment, but the equipment installation cost and maintenance cost become high, and the place where the ultra high voltage underground substation is installed is in the urban area, so there are restrictions on the place and volume, and the initial design In addition, easy changes are difficult. In addition, as shown in Patent Documents 1 to 6, conventionally, regarding a method for supplying cooling water for a cooling tower of an oil-feed water-cooled transformer, proposals regarding several control methods and control mechanisms have been made. No consideration has been given to countermeasures in the case of a shortage of cooling water during temporary overload operation as described above.

  Accordingly, an object of the present invention is to provide a cooling water supply method and apparatus for a cooling tower of a novel oil-feed / water-cooled transformer, in view of the state of the prior art. The present invention also reduces the amount of water used and the amount of water discharged by reducing the amount of water used and draining water by reducing the size and cost of the heat exchanger equipment and preventing a rapid increase in the conductivity of the cooling water even when the equipment is operating under high loads. It is an object of the present invention to provide a cooling water supply method and a device used therefor in a cooling tower of an oil-feed water-cooled transformer that can achieve the above.

  The present invention that solves the above problems is a method for supplying cooling water in a cooling tower of an oil-feed water-cooled transformer, wherein the cooling water has a variable amount relative to reverse osmosis membrane permeated water that is derived almost quantitatively. Mixing raw water to allow cooling water to be supplied at an arbitrary conductivity, detecting the water level in the mat water tank storing the cooling water in multiple stages, and if the water level in the mat water tank is at a high position, the conductivity of When relatively low cooling water is supplied and the water level in the mat water tank is low, the cooling water is supplied by increasing the conductivity and increasing the supply amount according to the degree of decrease. Is.

  In the cooling water supply method in the cooling tower of the oil-feed water-cooled transformer according to the present invention, the conductivity of the cooling water supplied by multistage detection is changed within a range of 30 to 200 μS / cm. It is desirable to be. In the cooling water supply method in the cooling tower of the oil-feed water-cooled transformer according to the present invention, the aspect in which the multi-stage detection is, for example, 3 to 4 stages is included.

  The present invention that solves the above-mentioned problem is also a cooling water supply device in a cooling tower of an oil-feed water-cooled transformer, and the reverse osmosis membrane permeates the raw water supplied from the raw water supply source and the raw water supply source. The reverse osmosis device for performing the treatment and the reverse osmosis membrane permeated water derived from the reverse osmosis device can mix the raw water from the raw water supply source in a variable amount and supply the cooling water at an arbitrary conductivity. The water quality improvement device, the mat water tank for storing the cooling water supplied from the water quality improvement device, the water level measurement device for detecting the water level of the cooling water in the mat water tank in multiple stages, and the water level measurement device A control mechanism is provided that adjusts the raw water mixing ratio in the water quality improvement device based on cooling water level information and supplies cooling water having a predetermined conductivity based on the water level information to the mat water tank. is there.

  According to the present invention, the water level detection in the mat water tank is multi-staged, and the conductivity of the cooling water to be supplied can be changed within an allowable range depending on the water level. Even when the amount of water used increases, the water level fluctuations in the mat water tank can be kept low, the water level drops significantly, and there is an emergency supply of raw water such as tap water. As a result, the rate of cooling water concentration can be maintained within a certain range, and a water-saving effect can be expected.

It is a figure which shows the balance of the evaporation amount of the cooling water in the cooling tower by the concentration rate of cooling water, the amount of used water, and the amount of drainage (blow water amount). It is a graph which shows the relationship of the amount of used water and the amount of drainage with respect to the concentration rate of cooling water. It is a graph which shows the relationship of the amount of supply water and the concentration rate with respect to the electrical conductivity of blend water. It is a figure which shows typically the control method of the cooling water in one embodiment of the supply method of the cooling water in the cooling tower of the oil-feeding water cooling type | formula transformer which concerns on this invention. It is a figure which shows typically the control method of the cooling water in the prior art example of the supply method of the cooling water in the cooling tower of an oil-feed water-cooled transformer. It is a figure which shows typically the control method of the cooling water in another one Embodiment of the supply method of the cooling water in the cooling tower of the oil-feeding water cooling type | formula transformer which concerns on this invention. It is a figure which shows typically the structural example of the water quality improvement apparatus used for the cooling water supply method in the cooling tower of the oil-feeding water cooling type | formula transformer which concerns on this invention. It is a figure which shows typically the structural example of the cooling water supply apparatus which applies the cooling water supply method in the cooling tower of the oil-feeding water cooling type | formula transformer which concerns on this invention. Water supply conditions (simulation No. 4) in one embodiment of the cooling water supply method in the cooling tower of the oil feeding water cooled transformer according to the present invention and water supply conditions (simulation No. 1 to 3) in the comparative example group, and It is a figure which shows a result. It is a graph which shows the concentration magnification with respect to the elapsed time in the comparative example 1, the amount of water used, the amount of mat tank water, and the change of electrical conductivity. It is a graph which shows the concentration magnification with respect to the elapsed time in the comparative example 2, the amount of water used, the amount of mat tank water, and the change of electrical conductivity. It is a graph which shows the concentration magnification with respect to the elapsed time in the comparative example 3, the amount of water used, the amount of mat tank water, and the change of electrical conductivity. 2 is a graph showing changes in concentration ratio, amount of water used, amount of mat tank water, and conductivity with respect to elapsed time in Example 1.

  Hereinafter, the present invention will be described in more detail based on embodiments.

  The cooling water supply method of the cooling tower of the oil-feed water-cooled transformer according to the present invention is based on the premise that the cooling water conductivity is reduced, the concentration factor is increased, and the amount of cooling water used for circulation and the amount of drainage are reduced. The application field is not particularly limited as long as the condition is satisfied. In the following, the present invention will be described with a focus on the embodiment of the cooling system for a large-capacity transformer in an ultrahigh voltage substation, but the present invention is not limited to such an embodiment. Besides, for example, cooling of a condenser such as a compression refrigerator, cooling of an absorber and a condenser of an absorption refrigerator can be used without particular limitation.

  Here, first, the water-saving effect on the cooling water concentration ratio can be explained as follows, for example.

(Calculation formula for water consumption / drainage)
M = (E × N) / (N−1)
B = E / (N-1)
(In the formula, N represents the concentration ratio, E represents the amount of evaporation, M represents the amount of water used, and B represents the amount of drainage.)

For example, as shown in FIG. 1, when the concentration factor is 2.0 times,
The balance of the evaporation amount of cooling water, the amount of water used, and the amount of drainage (blow water amount) in the cooling tower is represented as shown in the figure.

  Table 1 and FIG. 2 below show changes in the amount of water used and the amount of drainage with respect to the concentration rate.

  As shown in Table 1 and FIG. 2, when the concentration ratio of the cooling water is increased, there is a water saving effect, and the RO membrane permeated water that has been subjected to reverse osmosis membrane (RO membrane) treatment to reduce the conductivity as the cooling water. By using (deionized water), the concentration rate can be increased, and cooling water can be saved.

  As shown in Table 1 and FIG. 2, since the concentration rate is saturated at about 7 times, even if the concentration rate is further increased, the improvement in water-saving effect cannot be expected. On the other hand, if the total amount of cooling water is RO membrane permeated water, depending on the performance of the RO membrane treatment apparatus used, the conductivity of the water supply generally obtained is too low, and it reaches a considerably high concentration ratio. . At such a high concentration ratio, the cooling tower hardly blows, so that there is a high possibility that moss is generated or dirt is accumulated in the cooling tower. Moreover, the electrical conductivity of water supply is too low, and the bad effect that the water level meter measured by electrical conductivity does not operate | move well may also arise.

  From such a point, it is desirable that the cooling water is used by blending RO membrane permeate and city water so that an appropriate concentration rate can be obtained. Since the amount of water supplied to the apparatus can be increased by blending in this way, the initial cost can be reduced.

For example, by reverse osmosis membrane (RO membrane) treatment, a reverse osmosis membrane permeate having a conductivity of 12.5 μS / cm is obtained at a water amount of 3.00 m ³ / h, while the conductivity of tap water blended therein is increased. As shown in Table 2 and FIG. 3, by changing the amount of tap water to be blended, the conductivity of the feed water obtained after blending is 30-150 μS / cm. On the other hand, the water supply amount after blending can be about ^{3 to} 7 m ³ / h.

  Thus, in the present invention, the reverse osmosis membrane permeated water and raw water are blended as described above so that water can be supplied at an arbitrary conductivity, and the operating rate of equipment such as a transformer provided with a cooling tower is provided. The conductivity of the cooling water to be supplied is appropriately changed according to the fluctuation of the amount of cooling water used due to the influence of the fluctuation of the water.

  That is, in the cooling water supply method for the cooling tower of the oil-feed water-cooled transformer according to the present invention, a variable amount of raw water is mixed with the reverse osmosis membrane permeated water that is derived almost quantitatively to obtain an arbitrary conductivity. The cooling water can be supplied, the water level in the mat water tank storing the cooling water is detected in multiple stages, and when the water level in the mat water tank is at a high position, the cooling water having a relatively low conductivity is supplied to the mat water tank. When the water level in the water tank becomes a low position, the cooling water is supplied by increasing the conductivity and increasing the supply amount according to the degree of decrease.

  As is clear from the examples shown in Table 2 and FIG. 3 described above, if the conductivity of the feed water after blending is increased, the concentration rate can be reduced, but the amount of feed water can be increased. For this reason, if the water level of the mat water tank storing the supplied water is detected finely and the conductivity of the supplied water is changed depending on the water level, the decrease in the water level of the mat water tank increases due to an increase in the amount of cooling water used. Even if it is a case, the amount of water supply commensurate with the reduction amount can be secured. In this case, the conductivity of the feed water becomes high to some extent, but the conductivity of the mat water tank does not increase significantly.

  If it demonstrates more concretely by one Embodiment of this invention, the water supply system typically shown in FIG. 4 can be illustrated, for example.

  That is, under the assumption that the feed water after blending as shown in Table 2 and FIG. 3 can be obtained, as shown in FIG. 4, the number of electrodes of the water level sensor portion of the water level meter of the mat water tank can be increased. If the conductivity of the cooling water to be supplied is changed depending on the water level, and the amount of water is changed accordingly, the water level will drop to the minimum water level of the mat tank where the tap water valve for emergency replenishment will be `` open '' This does not occur, and the electrical conductivity of the mat water tank does not increase significantly, whereby the concentration ratio of the cooling water can be maintained within a certain range, and a water saving effect can be expected.

  The water level gauge is not particularly limited, but for example, an electrode type level switch can be used. Increasing the number of electrodes of the water level sensor of such a water level meter can be performed using a technique known in the art and is not particularly limited. For example, an electrode of an electrode type level switch is held. It can be easily changed by using a commercially available device known as an “electrode holder”, specifically, for example, an OMRON electrode holder PS series or the like having a large number of poles. Of course, it is not restricted to the form using such a commercial item at all.

  For reference, FIG. 5 shows a conventional water supply method to the mat water tank. As shown in FIG. 5, conventionally, even when the water level drop of the mat water tank becomes large due to an increase in the amount of cooling water used, a constant amount of reverse osmosis membrane permeated water has been continuously supplied. The supply water volume does not keep up with the decrease in the water volume of the mat tank, and eventually decreases to the minimum water level of the mat tank. Tap water was supplied until the mat tank reached the full position. As a result, the quality of tap water is almost the same in the mat water tank. Thus, when tap water is mixed significantly, the conductivity of the mat water tank increases. Once the conductivity of the mat water tank is increased, the concentration factor is decreased and the amount of water used is increased. In this way, once the cooling water stored in the mat water tank becomes almost tap water, it falls into a negative spiral, and the amount of water used increases significantly.

  As described above, in the present invention, the concentration rate of cooling water can be maintained within a certain range even when the amount of cooling water used varies as compared with the conventional cooling water supply method. Can be expected to save water.

  Then, according to the water supply method to the mat water tank as shown in FIG. 4, for example, in the cooling of the transformer in a substation or the like, it is possible to sufficiently absorb the annual fluctuation of the load factor of the transformer. That is, in winter and early spring when the load on the transformer is low and the amount of cooling water used is low, water with low conductivity is supplied as much as possible, for example, 30 μS / cm in the example shown in FIG. Improve water quality. In May and June, the load on the transformer increases and the amount of supplied water becomes insufficient. Therefore, water with a slightly high conductivity, for example, 70 μS / cm in the example shown in FIG. 4 is supplied. Furthermore, from July to September, the load on the transformer will rise further, and the amount of water supplied will be further shorted. Therefore, the conductivity is close to the allowable limit so that the tap water valve for emergency water replenishment will not open. Water of a relatively high level, for example, 150 μS / cm in the example shown in FIG. Of course, the numerical values of the conductivity and the conditions such as seasonal variations described above are merely examples given to explain the cooling water supply method in the cooling tower of the oil-feed water-cooled transformer according to the present invention, The present invention is not limited by these numerical values.

  In the cooling water supply method in the cooling tower of the oil-feed water-cooled transformer according to the present invention, the water level in the mat water tank is detected in multiple stages, and the conductivity of the cooling water is changed accordingly to supply water. Although the number of stages (the number of changes) is not particularly limited, if too many stages or continuous fluctuations are performed, the conductivity of the cooling water is controlled accordingly, that is, the RO membrane is permeated. Since the frequency of changing the mixing ratio of the raw water to the water is increased and the control thereof may be hindered, usually, for example, about 3 to 8 stages, for example, about 3 to 4 stages. More preferably, it is linear (the water level is measured linearly to change the conductivity).

  In addition, when changing the conductivity of the cooling water as described above in multiple stages, the range of the change depends on the use of the heat exchanger in which the cooling water is used. It is desirable that the rate be changed within a range of 30 to 200 μS / cm, more preferably within a range of 30 to 150 μS / cm. If it exceeds this range, the cooling water stored in the mat water tank will have an excessive concentration factor or an excessive concentration factor, and the water saving effect due to the use of RO membrane permeate will not be obtained. This is because there is a risk of losing.

  FIG. 6 is a diagram for explaining a calculation method for determining a water supply method to the mat water tank in still another embodiment of the present invention.

In the embodiment as shown in FIG. 4, the conductivity to be supplied is arbitrarily determined and confirmed by simulation, but further developed and cooled from the time when the water level is reduced by the method described below. The amount of make-up water necessary for the tower is automatically calculated, the water supply amounts T ₁ and T ₂ at the water level 2 and the water level 3 in FIG. 6 are obtained, and the conductivity to be set can be calculated.

That is, assuming that the amount of water in the mat water tank from the water level 1 to the water level 2 in FIG. 6 is W ₁ (m ³ ) and the time is t ₁ (h), the replenishing water amount Q ₁ per hour is obtained from these. At this time, since the water quality improvement device supplies the water supply amount T ₀ (= 3.24 m ³ / h) of the cooling water having conductivity 1, it is added.
Q ₁ = W ₁ / t ₁ +3.24
Tap water amount X = Q _1- RO membrane permeate water amount 3.0

As shown in Table 2 above, the amount of permeated water from the RO membrane is 3 m ³ / h, the permeated water conductivity is 12.5 μS / cm, the amount of tap water blended is Xm ³ / h, and the tap water conductivity is 250 μS. / Cm, the blend water conductivity D ₁ is
D ₁ = ((3 × 12.5) + (X × 250)) / (3 + X),
T ₁ = Tap water amount X + RO membrane permeate water amount 3.0 = Q ₁
It becomes.

Further, the water volume Q ₂ from the water level 2 to the water level 3 in FIG. 6 is determined as W ₂ (m ³ ) and the time t ₂ (h) as the amount of water in the mat water tank. At this time, since the water quality improvement device supplies the water supply amount T ₁ m ³ / h of the cooling water having conductivity 2, it is added.
Q ₂ = W ₂ / t ₂ + T ₁
Tap water amount X = Q ₂ -RO membrane permeate amount 3.0

When the permeate flow rate from the RO membrane is 3 m ³ / h, the permeate conductivity is 12.5 μS / cm, the tap water to be blended is Xm ³ / h, and the tap water conductivity is 250 μS / cm, the blend water conductivity D ₂ is
D ₂ = ((3 × 12.5) + (X × 250)) / (3 + X),
T ₂ = Tap water amount X + RO membrane permeate water amount 3.0 = Q ₂
It becomes.

  Thus, if the conductivity and the amount of water supplied at each stage are calculated from the amount of water reduced in the mat water tank, it is possible to supply water without opening the tap water valve for emergency replenishment.

  Next, the structural example of the water quality improvement apparatus used for the cooling water supply method of the cooling tower of the oil-feeding water cooling type | formula transformer which concerns on this invention is shown. In the embodiment shown in FIG. 7, the water quality improvement apparatus 1 includes a raw water storage tank 2, an activated carbon filtration apparatus 3, an ultrafiltration apparatus (UF apparatus) 4, a filtrate storage tank 5, and a reverse osmosis apparatus (RO apparatus). 6 and a blending device 12 that blends the raw water from the raw water storage tank 2 with the RO membrane permeate from the RO device at an arbitrary ratio. The raw water storage tank 2 stores raw water such as tap water and groundwater. The raw water in the raw water storage tank 2 is sent to the activated carbon filtration device 3 by the pump 10. The activated carbon filtration device 3 uses activated carbon as a filter medium, and has an activated carbon layer. By passing the raw water through the activated carbon filtration device 3, residual chlorine contained in the raw water is removed. The activated carbon filtration tank 3 is periodically backwashed with water flowing from the reverse side.

  The raw water that has passed through the activated carbon filtration tank 3 flows into the UF device 4. The UF device 4 includes a UF (ultrafiltration membrane), and removes suspended substances in the raw water. Similarly to the activated carbon filtration tank 3, the UF device 4 is regularly backwashed. The raw water that has passed through the UF device 4 is stored in the filtrate storage tank 5.

  The raw water in the filtrate storage tank 5 is pumped to the RO device 6 by the pump 11. The RO device 6 includes an RO membrane (reverse osmosis membrane), and raw water fed at a pressure higher than the osmotic pressure becomes deionized water.

  The cooling water that has passed through the RO device 6 is measured for conductivity by the conductivity measuring device 9 and sent to the blending device 12, where the conductivity is separately measured and the raw water storage tank 2 at a predetermined variable flow rate. The raw water is blended with the raw water, and the conductivity is set according to the water level of the stored water in the mat water tank 7 as described above, and is supplied to the mat water tank. The cooling water stored in the mat water tank 7 is appropriately supplied to the cooling tower 8 when the water level in the cooling tower 8 is lowered or when the conductivity of the cooling water is increased. The cooling tower 8 cools the large-capacity transformer 18 (see FIG. 8).

  The configuration example shown in FIG. 7 is merely an example, and in the water quality improvement apparatus, if the RO membrane permeated water and raw water are blended and the cooling water with the initial conductivity can be adjusted, the apparatus The configuration is not particularly limited.

  Further, FIG. 8 is a schematic view showing a part of a cooling tower of an oil-feed / water-cooled transformer to which the cooling water supply system according to the present invention is applied.

  The cooling water having a predetermined conductivity by the water quality improving apparatus 1 as described above is stored in the mat water tank 7. The cooling water is fed from here to the replenishing water tank 14 by the pump 13. From this replenishing water tank 14, cooling water is replenished as a replenishing water to a water storage tank 15 provided at the lower part of the cooling tower 8. Cooling water in the water storage tank 15 is sprinkled by a pump 16 from a sprinkling pipe 17 at the top of the cooling tower 8.

  The cooling object 18, which is a large-capacity transformer, is provided with outgoing and return chilled water pipes 19, 20 passing through the cooling tower 8. The cold water in the cold water pipes 19 and 20 is heat-exchanged with the cooling water cooled by the fan 22 rotated by the motor 21 in the cooling tower 8. That is, the chilled water heated by cooling the cooling object 18 enters the cooling tower 8 through the forward chilled water pipe 19, is cooled by heat exchange with the chilled water, and then cooled through the return chilled water pipe 20. The object 18 is cooled again.

  When the cooling water evaporates due to heat exchange in the cooling tower 8 and the conductivity becomes high, the water is drained from the water storage tank 15.

  Although the present invention has been described above by taking the configuration in the case of an open type cooling tower as an example, the present invention can be applied regardless of whether the cooling tower is an open type or a closed type. However, the present invention is not limited to the above-described embodiment.

  Hereinafter, the present invention will be described more specifically.

-Example 1 and Comparative Examples 1-3
Assuming seasonal variations in the evaporation amount of cooling water shown in FIG. 9, the concentration rate with respect to the elapsed time when the cooling water is supplied in the water-cooled heat exchanger according to the water supply conditions shown in FIG. The change of water quantity and conductivity was simulated. The obtained results are shown in FIGS. Simulation No. 1 shown in FIG. 1 to 3 are conditions in Comparative Examples 1 to 3, respectively, in which the conductivity of the feed water and the amount of water supplied were not changed in accordance with the change in the evaporation amount, etc. 4 is a condition in Example 1, and is an example in which the conductivity and the amount of water supplied are adjusted according to the fluctuation of the water level of the mat water tank according to the supply method of the present invention. As is apparent from the results shown in FIGS. 9 to 13, in Example 1 of the present invention, there is no shortage of water supply throughout the year, and about 5 to 6% of water can be saved annually compared to the comparative example. It was shown that

1 Water quality improvement device 2 Raw water storage tank 3 Activated carbon filtration device 4 Ultrafiltration device (UF device)
5 Filtrated water storage tank 5
6 Reverse osmosis equipment (RO equipment)
7 Mat water tank 8 Cooling tower 9 Conductivity measuring device 12 Blending device 18 Cooling object (transformer)

Claims (4)

  A method for supplying cooling water in a cooling tower of an oil-feeding water-cooled transformer, wherein as the cooling water, a variable amount of raw water is mixed with reverse osmosis membrane permeated water that is derived almost quantitatively, and an arbitrary conductivity is obtained. The cooling water can be supplied at, the water level in the mat water tank storing the cooling water is detected in multiple stages, and when the water level in the mat water tank is at a high position, the cooling water having a relatively low conductivity is supplied, A cooling tower of an oil-feeding water-cooled transformer characterized in that when the water level in the mat water tank is low, the cooling water is supplied by increasing the conductivity and increasing the supply amount according to the degree of the decrease. Supply method of cooling water in   2. The cooling water in the cooling tower of the oil-feed water-cooled transformer according to claim 1, wherein the conductivity of the supplied cooling water is changed within a range of 30 to 200 μS / cm by the multistage detection. Supply method.   The method for supplying cooling water in a cooling tower of an oil-feed / water-cooled transformer according to claim 1 or 2, wherein the multistage detection is performed in 3 to 4 stages.   A cooling water supply device in a cooling tower of an oil-feed water-cooled transformer, comprising a raw water supply source, a reverse osmosis device that performs reverse osmosis membrane permeation treatment on the raw water supplied from the raw water supply source, and the reverse A blend water supply mechanism capable of supplying a variable amount of raw water from the raw water supply source to the reverse osmosis membrane permeated water derived from a osmosis device and supplying cooling water at an arbitrary conductivity, and the blend water Based on a mat water tank that stores cooling water supplied from a supply mechanism, a water level measuring device that detects the water level of the cooling water in the mat water tank in multiple stages, and water level information of the cooling water detected by the water level measuring device An oil-feeding water-cooled transformer comprising a control mechanism that adjusts a raw water mixing ratio in the blend water supply mechanism and supplies cooling water having a predetermined conductivity based on water level information to the mat water tank. Cold Supply device of cooling water in the tower.

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