JP6401587B2 - Transformer cooling device, transformer cooling system, and transformer cooling method for underground substation - Google Patents

Description

  The present invention relates to a cooling facility for a substation facility, and more particularly, to a transformer cooling device, a transformer cooling system, and a transformer cooling method for an underground substation configured by integrating a dry cooling unit and a wet cooling unit.

  In general, substations installed in urban areas are often installed in the underground part of buildings and are called underground substations. This underground substation is an important facility for power transmission and distribution in urban areas, and the largest is a 500 kV class facility. Such underground substations tend to close up as a social problem such as disruption of the urban area due to the fact that power is supplied to major institutions in the urban area. Therefore, improving the reliability of underground substations is a major proposition.

  Because of the circumstances described above, not only high reliability is required for equipment (for example, transformers) that make up substations, but also high reliability is required for auxiliary equipment (for example, transformer cooling systems). Sex is required. For example, a transformer cooling system that forms an underground substation is required to have high reliability because the stop of the cooling system is directly connected to the stop of the transformer (self-damage due to heat).

  In addition to being installed in urban areas where electricity demand is high, underground substations are installed on the basement floors of buildings, so it is difficult to dissipate large amounts of heat generated by transformers, etc. It is necessary to forcibly release heat from the underground floor to the outside (above ground), and the cooling facilities of underground substations tend to be larger and more complex than substations installed outdoors.

  A general underground substation cooling facility system exchanges heat generated in a transformer in the process of chilled water becoming hot water in a primary cooler installed in the transformer, and then heat from the primary cooler (primary cooling). The cooling water after the heat exchange in the cooler is sent to the secondary cooler by the circulating water pump, and the heat is exchanged in the process where the hot water becomes cold water by the secondary cooler. As an example of cooling equipment for substation equipment that employs the above-described structure, for example, a cooling system described in Japanese Patent Application Laid-Open No. 2001-91189 is known (for example, see Patent Document 1).

  In the transformer cooling system for an underground substation described in the cited reference 1, a wet cooler such as a cooling tower or a dry cooler is used as a secondary cooler. A cooling tower that can also be used as a dry cooler, that is, a cooler that can be used as both a dry cooler and a wet cooler, may be used as a secondary cooler.

  When a cooling tower is used as a wet cooler, the circulating water after absorbing the heat of the transformer, which is the object to be cooled, is introduced into the cooling tower, and the cooling fan (cooling air) inside the cooling tower is inside the cooling tower. ) And watering pump (spray water). Examples of the cooling tower include an open type cooling tower and a closed type cooling tower that can suppress contamination of circulating water.

JP 2001-91189 A

  In the transformer cooling system for an underground substation described in the above cited reference 1, a cooling tower is used as a cooling facility for the transformer, and any of an open cooling tower and a closed cooling tower is adopted. Even a large amount of water is required. More specifically, since the open type cooling tower is cooled by using latent heat of evaporation when the circulating water is directly opened to the atmosphere and evaporated, a large amount of water is used inside the cooling tower. In addition, the closed cooling tower sprays sprayed water directly on the heat exchange section through which the circulating water is passed and cools it using this latent heat of vaporization. Used for.

  In the case of underground substations that use cooling towers as the cooling equipment for transformers, although depending on the scale of the facility, the water charge required to operate the cooling equipment is tens of millions to several years per year for large facilities. In order to reach 100 million yen, there is a need to reduce the water charge, that is, to save water.

  In addition, considering the occurrence of large-scale disasters such as earthquakes directly below the Tokyo metropolitan area that have been warned recently, there is a high possibility that water supply will be cut off at the time of disasters such as earthquakes directly below the Tokyo metropolitan area. It is expected that it will take a considerable number of days to recover. Therefore, transformer cooling systems for underground substations that require a large amount of water have the risk of stopping cooling facilities and eventually stopping underground substations, and it is necessary to reduce the risk of stopping such cooling facilities as much as possible. Yes. From such a background, it is desirable that the transformer cooling system of the underground substation is a transformer cooling system capable of continuously cooling the transformer without using water as much as possible.

  On the other hand, if a dry-type cooler that does not use a cooling tower is used as a cooling facility for the transformer, the above problem seems to be solved. However, the dry cooler does not use water compared to the wet cooler, so the heat exchange efficiency is poor because the large latent heat of water cannot be used, and the same amount of heat is exchanged. Therefore, a larger heat transfer area than that of the wet cooler is required, and there is a problem that the apparatus is enlarged.

  Therefore, in general, the heat generation capacity of the transformer is large, so the cooling capacity of the cooling facility is large and the installation area is small, so it is not a story that simply replaces the cooler with a dry-type cooler. It is necessary to be a cooling facility that can be installed within the area. Also, considering the cost, installation space, and minimization of construction work, it is desirable that the cooling equipment for the transformer is as compact as possible.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a transformer cooling device, a transformer cooling system, and a transformer cooling method for an underground substation that uses less water as much as possible and saves space. And

In order to solve the above-described problems, a transformer cooling device for an underground substation according to an embodiment of the present invention is provided on a path through which circulating water circulates, and is installed in the underground substation by exchanging heat with the circulating water. The hot water, which is the circulating water after passing through the primary cooling means, is installed on the path where the circulating water circulates at a position away from the primary cooling means for removing the generated heat of the transformer This is a transformer cooling device, and uses the water for cooling at high temperature and high load by supplying the taken outside air as cold heat to the first heat exchange part that exchanges heat with the circulating water supplied in the device. At least one dry cooler capable of dry operation and a second heat exchanger for exchanging heat with circulating water after passing through the dry cooler , water for cooling at the time of high temperature and high load To supply cold heat and cool the circulating water Comprising at least one or more open cooling towers capable equation operation, said at least one or more dry coolers, and a common blowing means for generating an air flow which sequentially ventilating the open cooling tower, the said The second heat exchanger is disposed outside the open-type cooling tower, and the circulating water after passing through the at least one dry cooler passes through the primary side, and passes through the secondary side. The open-type cooling tower and the second heat exchanger are circulated, and the sprayed water released to the atmosphere sprayed by the open-type cooling tower is passed through, and the at least one or more open The mold cooling tower can switch the wet operation on and off, and is configured to be able to switch the wet operation on during the high temperature and high load .
Alternatively, the circulating water is provided on a path through which the circulating water circulates, and is located away from the primary cooling means that removes the heat generated by the transformer installed in the underground substation by exchanging heat with the circulating water. A transformer cooling device that is installed on a path through which water circulates and cools hot water that is circulating water after passing through the primary cooling means, and that exchanges heat with the circulating water supplied into the device. By supplying the taken-out outside air as cold heat to the exchange unit, at least one dry cooler capable of dry operation without using water for cooling at high temperature and high load, and the dry cooler were passed through. At least one or more open type cooling towers capable of performing a wet operation for cooling the circulating water later, the at least one or more dry type coolers, and a common air blown that generates an air flow for sequentially passing the open type cooling towers Means A first flow path for supplying circulating water after passing through the at least one dry cooler to the outside, and at least circulating water after passing through the at least one dry cooler A second flow path for supplying one or more open cooling towers; a first valve for opening and closing the first flow path; and a second valve for opening and closing the second flow path. The at least one open type cooling tower opens the circulating water supplied by closing the first valve and opening the second valve in the tower, and evaporates after opening to the atmosphere. The circulating water cooled by latent heat is supplied to the outside, and the at least one open cooling tower can switch the wet operation on and off, and the wet operation is performed at the time of the high temperature and high load. Is configured to be switched on.

  In order to solve the above-described problems, a transformer cooling system for an underground substation according to an embodiment of the present invention is provided on a path through which circulating water circulates, and is installed in the underground substation by exchanging heat with the circulating water. The primary cooling means for removing heat generated from the transformer to be removed from the transformer and the primary cooling means are installed on a path where the circulating water circulates at a position away from the primary cooling means and passes through the primary cooling means. A transformer cooling system for an underground substation comprising secondary cooling means for cooling hot water that is later circulating water, and applying the transformer cooling device for the underground substation as the secondary cooling means. Features.

The transformer cooling method of an underground substation according to an embodiment of the present invention is a transformer cooling method of an underground substation using the above-described transformer cooling system in order to solve the above-described problem, and the circulation measured Based on the temperature of the water, it is determined whether the high temperature / high load or the normal operation is not the high temperature / high load. If the determination result is the normal operation, the dry operation is performed. was turned on, the steps for turning off the wet operation, when the judgment result is at the high temperature and high load, the dry operation is turned on, comprising the steps of: turning on the wet operation It is characterized by that.

  According to the present invention, it is possible to greatly reduce the amount of water used in the cooling facility for cooling the object to be cooled.

The equipment block diagram which showed roughly the underground substation transformer cooling device which concerns on the 1st Embodiment of this invention. The system block diagram which showed roughly the transformer cooling system of the underground substation which concerns on the 1st Embodiment of this invention, and its cooling system. The processing flowchart which shows the operation control procedure in the transformer cooling device and transformer cooling system of an underground substation which concerns on embodiment of this invention. The more detailed process flow figure of the cooler recommendation operation state judging step (Step S5: Drawing 3) in the operation control procedure in the transformer cooling device and transformer cooling system of an underground substation concerning the embodiment of the present invention. Explanatory drawing (graph) which shows the relationship between a cooling air temperature and the load factor in the wet bulb temperature over 27 degreeC, and thermal performance. The apparatus block diagram which showed roughly the underground substation transformer cooling device which concerns on the 2nd Embodiment of this invention. The system block diagram which showed roughly the transformer cooling system of the underground substation which concerns on the 2nd Embodiment of this invention, and its cooling system. The system block diagram (modification) which showed roughly the transformer cooling system (normal time) of the underground substation which concerns on the 2nd Embodiment of this invention, and its cooling system. The apparatus block diagram which showed roughly the substation transformer cooling device (normal time) which concerns on the 3rd Embodiment of this invention. The system block diagram which showed roughly the transformer cooling system (normal time) of the underground substation which concerns on the 3rd Embodiment of this invention, and its cooling system.

  Hereinafter, an underground substation transformer cooling device, a transformer cooling system, and a transformer cooling method (hereinafter referred to as “underground substation transformer cooling device”, “underground substation transformer cooling”, respectively, according to embodiments of the present invention. System "and" Substation transformer cooling method ") will be described with reference to the drawings.

  The underground substation transformer cooling system according to the embodiment of the present invention has a cooling device (secondary cooling means) different from the conventional underground substation transformer cooling system, and the underground substation according to the embodiment of the present invention. The transformer cooling device of the substation is provided as a secondary cooling means. Therefore, first, an outline of an underground substation transformer cooling device according to an embodiment of the present invention will be described.

  In addition, the cooling system of the substation substation equipment is designed so that the cooling capacity of the cooling equipment can be cooled even in the summer, with 100% of the heat generated by all the main units (cooled bodies) such as transformers in each bank. It is common to be done. However, the load factor of a transformer or the like in an underground substation is usually 60% or less, and generally about 80% at the maximum.

  Further, as a domestic standard, the designed outside air temperature set value is usually set to a temperature that takes into account the past maximum temperature (for example, dry bulb temperature 40 ° C., wet bulb temperature 27 ° C.). The temperature set for overseas plants and air conditioning systems is 0.4% dry bulb (DB) and wet bulb (WB) from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). ) With the 0.4% standard as the highest class temperature, it takes a very short time (about 35 hours per year) when the outside air temperature reaches the highest class temperature with respect to the total operating time of the year (365 days × 24 hours = 8760 hours). In many cases, the design temperature is set to be low, assuming that the total operating time is about 0.4% of the total operating time. In this case, the dry bulb temperature is 33.2 ° C. and the wet bulb temperature is 24.9 ° C. in Tokyo.

  Therefore, almost no load is operated at 100% of the design value at the underground substation, and it is usually about 60%, and the time when the outside air temperature exceeds the design value is based on past weather data (2014 Considering the fact that the former standard is zero hours and the latter standard is very small (about 0.4%), as a practical operation, both domestic and overseas plants are substations. Even if the cooling capacity of the cooling equipment of the substation transformer cooling system is about 60% of the design value, the operation of the underground substation can be substantially covered.

  In view of the above circumstances, an underground substation transformer cooling device according to an embodiment of the present invention is operated in a situation where the outside air temperature is low and the load on the underground substation is low (the load factor is approximately 60% or less) (hereinafter, “normal operation”). And switching in operation (hereinafter referred to as “high load operation”) in a situation where the outdoor temperature is high in summer and the load on the underground substation is high (load factor is generally over 60%). Configured as one of the facilities. In addition, water can be saved significantly by adopting a configuration that does not use water during normal operation, which occupies most of the year (limits the use of water during high-load operation).

  On the other hand, the underground substation transformer cooling system according to the embodiment of the present invention is different in that the transformer cooling system is constructed using the underground substation cooling device according to the embodiment of the present invention. In the configuration other than the substation cooling device, there is no substantial difference from the conventional underground substation substation equipment cooling system, and the cooling method is common in that circulating water is circulated. Therefore, in each of the embodiments described later, the explanation will focus on the cooling equipment for the underground substation transformer cooling system configured using the underground substation transformer cooling device and the underground substation transformer cooling device. In general, underground substations in urban areas have a three-bank configuration. From the viewpoint of simplifying the description, a cooling system and a cooling system for one bank will be described.

[First Embodiment]
FIG. 1 shows an underground substation transformer cooling device (hereinafter referred to as a “first underground substation transformer cooling device”) which is an example of an underground substation transformer cooling device according to the first embodiment of the present invention. .) Device configuration diagram schematically showing 10A, FIG. 2 is an example of an underground substation transformer cooling system (hereinafter referred to as “the substation transformer cooling system”) according to the first embodiment of the present invention. It is referred to as a “first underground substation transformer cooling system.”) A system configuration diagram schematically showing a cooling system 70 centering on a cooling facility of 30A (shown in FIG. 2 is one bank). .

  The first underground substation transformer cooling device 10A is, for example, a dry cooling means that does not use water that exchanges heat between outside air (generally air) 1 taken from the outside and cooling water flowing in the pipe. In the subsequent stage of this dry-cooling means, a slight outside air temperature generated in summer or the like is high and the load on the underground substation is high (load factor is generally over 60%) (hereinafter referred to as “high temperature and high load”). In the case of.), A wet cooling means for releasing heat from the cooling water after passing through the dry cooling means using water for cooling is integrally provided. Here, that the dry cooling means and the wet cooling means are integrally provided means that the air blowing means of the dry cooling means and the air blowing means of the wet cooling means are shared, that is, the dry cooling means and the wet cooling. It means having one common air blowing means (hereinafter referred to as “common air blowing means”) for ventilating the outside air with respect to two different types of cooling means.

  In the first underground substation transformer cooling device 10A, at least one dry cooler 11 such as two (FIG. 1), for example, is used as the dry cooling means, and one (FIG. 1) is provided as the wet cooling means, for example. Are installed in the outside air intake port of the open type cooling tower 12 which is an example of at least one wet cooler.

  In the first underground substation transformer cooling device 10 </ b> A, by operating the blower 121 as a common blower installed in the upstream stage of the open type cooling tower 12, the outside air 1 is first brought into the dry cooler 11. After being introduced and ventilated through the heat transfer section 111 of the dry cooler 11, it is guided to the inside of the open type cooling tower 12 without being exhausted outside the apparatus by the duct 112, and exhausted from the inside of the open type cooling tower 12 to the outside. That is, the blower 121 of the first underground substation transformer cooling device 10 </ b> A is shared by the dry cooler 11 and the open cooling tower 12.

  The first underground substation transformer cooling device 10A has an open main system in which the cooling water sent into the device passes through the primary side of the dry cooler 11 and the heat exchanger 13 and then is sent out of the device. A cooling system having a secondary system that circulates between the mold cooling tower 12 and the secondary side of the heat exchanger 13 is provided.

  Further, in the first underground substation transformer cooling device 10A, in order to dissipate the heat of the cooling water after passing through the dry cooler 11, at least one heat exchanger 13 such as a plate heat exchanger is provided. A stand is installed. Cooling water after passing the dry cooler 11 is introduced to the primary side of the heat exchanger 13, and circulating water supplied from the open type cooling tower 12 is introduced to the secondary side.

The first underground substation transformer cooling device 10A determines the operating state,
(1) Both the dry cooler 11 and the wet cooler (open cooling tower 12) are off, that is, the blower 121 and the watering pump 122 are stopped.
(2) The dry cooler 11 is on, the wet cooler (open cooling tower 12) is off, that is, the blower 121 is in operation, the watering pump 122 is stopped,
(3) Both the dry cooler 11 and the wet cooler (open cooling tower 12) are on, that is, the blower 121 and the watering pump 122 are in operation.
It is possible to switch to three stages.

  In other words, the first underground substation transformer cooling device 10 </ b> A performs the operation stages (1) to (3) as the first operation stage (dry operation) and the second operation stage (dry type), respectively. Operation) and the third operation stage (wet operation), the operation stage can be switched, and the first operation stage to the third operation stage (cooling stage) depending on the required cooling capacity ) Can be selected.

  The cooling stage in the first underground substation transformer cooling device 10A is, for example, (1) to (1) to (1) to (1) to (1) to (2) depending on the temperature of circulating water flowing through the primary cooling means 72, It can be switched by switching the operation stage of 3).

  In the first underground substation transformer cooling device 10A configured as described above, it is necessary to regularly (mainly) use the dry-type cooler 11 as a means for exchanging heat with circulating water to further increase the cooling capacity. Only in the case (at the time of high temperature and high load), flexible operation such as preliminarily using the open cooling tower 12 as a wet cooler using water for cooling becomes possible.

  The first underground substation transformer cooling device 10A has a configuration in which the blower 121 is shared by the dry-type cooler 11 and the open-type cooling tower 12, and therefore, it seems that it is difficult to manufacture unless it is made to order. However, based on the dry cooler 11 and the general-purpose open cooling tower 12, general construction such as installation / removal of equipment such as the blower 121, wiring work, addition of the duct 112 (welding work), and the like. Can be manufactured.

  Further, when the first underground substation transformer cooling device 10A is manufactured based on the dry type cooler 11 and the general-purpose open cooling tower 12, the output of the blower 121 is increased (for example, the rated output of 3.7 kW is increased). However, it is relatively easy to cope with this.

  For example, in the general-purpose open cooling tower 12, there is a case where the blower 121 cannot originally cover the pressure loss and the blower installation support strength is insufficient. In this case, it is possible to cope with the problem by additionally installing the blower 121 including the support device. Moreover, when support strength is enough, it can respond by removing the air blower 121 and its related apparatus, and replacing the air blower 121 of higher output.

  On the other hand, as illustrated in FIG. 2, the first underground substation transformer cooling device 10 </ b> A can be applied as a secondary cooling means of a general underground substation transformer cooling system. In the first underground substation transformer cooling system 30A provided with the first underground substation transformer cooling device 10A as a secondary cooling means, the heat generated in the transformer 3 as a cooled object is radiated to radiate heat. The vessel 3 is cooled (heat radiation).

  The cooling system 70 in the first underground substation transformer cooling system 30 </ b> A is a system in which circulating water (cooling water) cooled by the first underground substation transformer cooling device 10 </ b> A is circulated by the circulating water pump 71. In the first underground substation transformer cooling system 30A, a flow path configured by connecting the primary cooling means 72 and the first underground substation transformer cooling device 10A as the secondary cooling means, that is, circulation. Circulating water circulates in a flow path formed by connecting the output side of the water pump 71, the primary side of the dry cooler 11, the heat exchanger 13, the primary cooling means 72, and the input side of the circulating water pump 71. Flowing.

  The primary cooling means 72 (heat exchanger) has a function of radiating the heat generated by the transformer (cooled body) 3 to the circulating water. The primary cooling means 72 (heat exchanger) removes heat generated by the transformer 3 from the transformer 3 by exchanging heat with circulating water having a temperature lower than that of the transformer 3.

  The first underground substation transformer cooling device 10A as the secondary cooling means is provided at a position distant from the primary cooling means 72, and cools the circulating water (hot water) after passing through the primary cooling means 72. It has the function to do. The first underground substation transformer cooling device 10 </ b> A (secondary cooling means) cools the circulating water that has become hot water by the heat generated by the transformer 3 by radiating the heat of the circulating water (heat exchange). The circulating water that has become cold water is reintroduced from the first underground substation transformer cooling device 10A to the primary cooling means 72 (heat exchanger) on the transformer 3 side, and the primary cooling means 72 and the first underground substation transformer are transformed. It circulates through the flow path constituted by connecting the cooling device 10A (secondary cooling means).

  The cooling system 70 is also provided with a makeup water tank 73 that stores makeup water and a thermometer 75 that measures the temperature of the circulating water.

  The makeup water tank 73 appropriately supplies the makeup water stored therein to the cooling system 70 and the open cooling tower 12 (wet cooler).

  The thermometer 75 is installed, for example, on the side (inlet side) where the circulating water flows into the primary cooling means 72 and measures the temperature of the circulating water flowing into the primary cooling means 72. The temperature information (circulated water temperature TE) acquired by the thermometer 75 is input to the control device 31A, for example, and used for operation control of the first underground substation transformer cooling device 10A by the control device 31A.

  In the first underground substation transformer cooling system 30A, based on the control command from the control device 31A, the first underground substation transformer cooling device 10A is changed among the three stages (1) to (3). The operation can be switched to any operation stage. Therefore, the first underground substation transformer cooling system 30A can be operated by switching the cooling stage (operation stage) according to the required cooling capacity.

  The switching of the cooling stage in the first underground substation transformer cooling device 10 </ b> A is performed according to, for example, the temperature of the circulating water flowing through the primary cooling means 72, that is, the circulating water temperature TE acquired by the thermometer 75. As the circulating water temperature TE increases, the numbers in parentheses (1) → (2) → (3) are switched from the small to the large cooling stage. On the other hand, when the circulating water temperature TE becomes low, the numbers in parentheses (3) → (2) → (1) are switched from the large to the small cooling stage.

  As described above, in the first underground substation transformer cooling system 30A including the first underground substation transformer cooling device 10A, the operating state of the dry type cooler 11 and the open type cooling tower 12 as the wet type cooler is set. By appropriately switching according to the temperature of the circulating water (circulating water temperature TE), an appropriate cooling stage is selected and the circulating water flowing through the primary cooling means 72 is continuously cooled.

  FIG. 3 shows an operation control procedure (cooling stage) of the first underground substation transformer cooling device 10A as an example of the operation control procedure in the transformer cooling device and transformer cooling system of the underground substation according to the embodiment of the present invention. It is an operation | movement flowchart which shows a switching procedure. FIG. 4 is a more detailed process flow diagram of the cooler recommended operation state determination step (step S5) in the operation control procedure (cooling stage switching procedure: FIG. 3).

  Note that T1 and T2 shown in FIG. 4 are threshold values for ON determination (set temperature) for shifting the operation state of the cooler (dry cooler and wet cooler) from the stopped state (off) to the operating state (on). These are the threshold for determining the start of the blower 121 (FIGS. 1 and 2) and the threshold for determining the start of the watering pump 122, respectively. The relationship between the threshold values T1 and T2 is T1 <T2. Further, α and β shown in FIG. 4 are OFF determination setting values (arbitrary real numbers that are 0 or more) set for OFF determination for shifting the operation state of the cooler from the operation state to the stop state.

  The operation control procedure (steps S1 to S8) illustrated in FIG. 3 is executed by the control device, and the circulating water pump operation transition process (steps S1 and S2), the cooling water temperature control process (steps S3 to S8), and It comprises.

  The processing step of the operation control procedure is started when the cooling of the transformer as the object to be cooled starts. In the circulating water pump operation transition step (steps S1 and S2), the circulating water pump is shifted to the operating state.

  That is, it is determined whether or not the circulating water pump is operated (step S1), and when the circulating water pump has not yet started operation (NO in step S1), the circulating water pump 71 is activated. The operation is started (step S2), and the circulating water pump operation transition process (steps S1 and S2) is completed.

  On the other hand, when the circulating water pump 71 is already in operation (YES in step S1), the circulating water pump operation transition process (steps S1 and S2) is completed. When the circulating water pump operation transition process is completed, the processing flow of the operation control procedure proceeds to the next processing step (step S3).

  In the cooling water temperature control step (steps S3 to S8), the thermometer 75 (FIG. 2) acquires the circulating water temperature TE (step S3), and the second cooling unit as the secondary cooling means is obtained according to the acquired circulating water temperature TE. The operation state of the underground substation transformer cooling device 10A (FIG. 2), that is, the dry cooler 11 (FIG. 2) and the open cooling tower 12 (FIG. 2) is switched (step S4 to step S7).

  After the circulating water temperature TE is acquired (step S3), first, the current operation state of the dry cooler 11 and the open cooling tower 12 is confirmed (step S4). The current operation state of the dry cooler 11 and the open cooling tower 12 is monitored and grasped by the control device 31A (FIG. 2). When the confirmation of the current operation state of the dry cooler 11 and the open cooling tower 12 is completed, a cooler recommended operation state determination step is subsequently performed (step S5).

  In the cooler recommended operation state determination step, it is determined which cooling stage the dry cooler 11 and the open cooling tower 12 should be based on from the obtained circulating water temperature TE, that is, a recommended operation stage (about a detailed determination flow) Will be described later). More specifically, it is determined which of the first, second, and third operation stages (1) to (3) described above should be recommended.

  In the cooler recommended operation state determination step (step S5), when it is determined which operation stage the dry cooler 11 and the open cooling tower 12 should be operated on, the confirmation result of step S4, that is, the current dry type is determined. The operating state of the cooler 11 and the open type cooling tower 12 and the determination result of step S5, that is, the recommended operating state of the dry type cooler 11 and the open type cooling tower 12 (any of the first to third operating stages). Are compared (step S6).

  Here, when the operation state matches (in the case of YES in step S6), it is confirmed whether or not the transformer 3 is stopped (step S8), and when it is stopped (in the case of YES in step S8). On the other hand, when the operation control procedure is finished (END), while being in operation (NO in step S8), the processing flow of the cooling water temperature control process returns to step S3, and the processing steps after step S3 are executed. Is done.

  On the other hand, when the operation state does not match (NO in step S6), the operation stage of the dry cooler 11 and the open cooling tower 12 is switched to the operation stage determined by the control device 31A in step S5. That is, the operation state of the dry cooler 11 and the open type cooling tower 12 is switched (step S7). When the switching of the operation state is completed, the processing flow of the cooling water temperature control process proceeds to step S8, and the processing steps after step S8 are executed.

  Then, with reference to FIG. 4, the more detailed process content (step S501-step S509: FIG. 4) of a cooler recommended operation state determination step (step S5: FIG. 3) is demonstrated.

  The cooler recommended operation state determination steps (steps S501 to S509) are processing steps for determining an operation stage that should be recommended, and the current operation stage is maintained in the cooling water temperature control step (FIG. 3). This relates to step S5 for providing information for determining whether or not to switch (should be switched).

  In the cooler recommended operation state determination step (ENTER), first, when the current operation stage of the dry cooler 11 (FIG. 2) and the open type cooling tower 12 (FIG. 2) is the first operation stage (step S501). YES), the circulating water temperature TE and the temperature (threshold value) T1 set as the temperature for turning on the blower 121 of the first underground substation transformer cooling device 10A (dry cooler 11 and open cooling tower 12) Are compared (step S502).

  Here, when the circulating water temperature TE is lower than T1, that is, when TE ≧ T1 is not satisfied (NO in step S502), the operation stage of the dry cooler 11 and the open cooling tower 12 is set to the first operation stage. It is determined that the first operation stage is recommended (step S503). On the other hand, when the circulating water temperature TE is equal to or higher than T1, that is, when TE ≧ T1 is satisfied (YES in step S502), the operation stage of the dry cooler 11 and the open cooling tower 12 should be the second operation stage. A determination (recommended second operation stage) is made (step S504). When the recommended operation stage is determined (steps S503 and S504), the cooler recommended operation state determination step is completed (RETURN). After completion of the cooler recommended operation state determination step, step S6 shown in FIG. 3 is executed.

  Subsequently, when the current operation stage of the dry cooler 11 and the open type cooling tower 12 is the second operation stage (NO in step S501 → YES in step S505), the circulating water temperature TE and the dry cooler 11 is compared with the temperature (threshold value) T1-α set as the temperature at which the blower 121 is turned off (step S506).

  Here, when the circulating water temperature TE is equal to or lower than T1-α, that is, TE ≦ T1-α (YES in step S506), the operation stage of the dry cooler 11 and the open cooling tower 12 is the first operation. It is determined that the operation should be performed (the first operation phase is recommended) (step S503), and the cooler recommended operation state determination step is completed (RETURN).

  On the other hand, the circulating water temperature TE is higher than T1-α, and is set as a temperature at which the watering pump 122 of the first underground substation transformer cooling device 10A (dry cooler 11 and open cooling tower 12) is turned on. If the temperature (threshold value) is less than T2, that is, TE ≦ T1-α is not satisfied and TE ≧ T2 is not satisfied (NO in step S506 → NO in step S507), the dry cooler 11 and the open cooling tower The operation stage 12 is determined to be the second operation stage (the second operation stage is recommended) (step S504), and the cooler recommended operation state determination step is completed (RETURN).

  Further, when the circulating water temperature TE is equal to or higher than T2 exceeding T1-α, that is, TE ≦ T1-α is not satisfied and TE ≧ T2 is satisfied (NO in step S506 → YES in step S507), dry cooling is performed. It is determined that the operation stage of the vessel 11 and the open type cooling tower 12 should be the third operation stage (the third operation stage is recommended) (step S508). When the recommended operation stage is determined (step S508), the cooler recommended operation state determination step is completed (RETURN).

  Subsequently, when the current operation stage of the dry cooler 11 and the open type cooling tower 12 is the third operation stage (NO in step S501 → NO in step S505), the circulating water temperature TE is set to the water spray pump 122. Is compared with a temperature (threshold value) T2-β set as a temperature for turning off (step S509).

  As a result of the comparison, when the circulating water temperature TE is equal to or lower than T2-β, that is, when TE ≦ T2-β is satisfied (YES in step S509), the operation stages of the dry cooler 11 and the open cooling tower 12 are performed. Is to be in the second operation stage (the second operation stage is recommended) (step S504), and the cooler recommended operation state determination step is completed (RETURN).

  On the other hand, when the circulating water temperature TE exceeds T2-β, that is, when TE ≦ T2-β is not satisfied (NO in step S509), the operation stages of the dry cooler 11 and the open cooling tower 12 are changed. It is determined that the third operation stage should be performed (the third operation stage is recommended) (step S508), and the cooler recommended operation state determination step is completed (RETURN).

  Next, the cooling capacity of the cooling equipment (mainly secondary cooling means) and the cooling capacity of the wet cooling means in the underground substation transformer cooling system according to the embodiment of the present invention, and the underground substation according to the embodiment of the present invention The usefulness of the transformer cooling system will be explained.

  In the substation transformer cooling system according to the embodiment of the present invention, the operation state of the secondary cooling means is dry operation at normal load (dry cooling means on, wet cooling means off), and wet operation at high loads. (The dry cooling means is on and the wet cooling means is on). For example, in the first underground substation transformer cooling system 30A (FIG. 2), the blower 121 is turned on and the water spray pump 122 is turned off during normal load. On the other hand, when the load is high, the blower 121 is turned on and the watering pump 122 is turned on.

  Further, in the substation transformer cooling system according to the embodiment of the present invention, the outside air temperature in the hottest summer season throughout the year (for example, a dry bulb temperature of 40 ° C. and a wet bulb temperature of 27 ° C. considering the highest temperature in the past). As a design temperature, the dry cooling means as the secondary cooling means and the cooling capacity (cooling capacity) of the wet cooling means are determined. The cooling capacity of the dry cooling means and the cooling capacity of the wet cooling means are determined such that the total cooling capacity is equal to or greater than the amount of heat generated during 100% load operation of the transformer 3 (FIG. 1).

  Furthermore, in the underground substation transformer cooling system according to the embodiment of the present invention, unlike the general underground substation transformer cooling system, the design temperature of the dry cooling means and the design temperature of the wet cooling means are individually ( Set). Taking the first underground substation transformer cooling system 30A (FIG. 2) as an example, the design temperature of the dry cooler 11 as the dry cooling means and the design temperature of the open cooling tower 12 as the wet cooling means Differently set.

  Here, the design temperature is a temperature at which 100% load operation of the transformer 3 is possible if the temperature is equal to or lower than the temperature. For example, when the design temperature is 30 degrees, if the temperature is 30 degrees or less, the transformer 3 can be operated at 100% load.

  The design temperature of the dry cooler 11 (dry cooling means) is based on the dry bulb temperature in the hottest midsummer of the place where the underground substation is installed. For example, in Tokyo and the like, the design temperature is a dry bulb temperature of 40 ° C.

  The design temperature of the open-type cooling tower 12 is based on the wet bulb temperature in the hottest midsummer of the place where the underground substation is installed. For example, the highest wet bulb temperature is adopted for a predetermined period such as the past 30 years. Etc. can be determined. For example, in Tokyo and the like, a wet bulb temperature of 27 ° C. is set as the design temperature. However, the wet-cooler inlet wet bulb temperature needs to take into account the wet bulb temperature rise caused by the air that has entered the dry cooler 11 at the dry bulb temperature being warmed in the dry cooler 11.

  Further, the cooling capacity of the first underground substation transformer cooling device 10A (FIG. 2) as the secondary cooling means of the first underground substation transformer cooling system 30A (FIG. 2), that is, the dry cooler 11 The total cooling capacity of the cooling capacity and the cooling capacity of the open type cooling tower 12 is determined so as to be equal to or greater than the amount of heat generated during the 100% load operation of the transformer 3. In addition, the cooling capacity of the dry cooler 11 is set to a cooling capacity that allows 100% load operation of the transformer 3 only by the operation of the dry cooler 11 under the condition of a dry bulb temperature of 18 ° C., which is lower than the design temperature.

  Subsequently, when the first underground substation transformer cooling system 30A (FIG. 2), which is an example of the underground substation transformer cooling system according to the embodiment of the present invention, exceeds the cooling air temperature (inlet air temperature), The extent to which the load factor can be handled only by dry operation will be described, and the utility of the underground substation transformer cooling device and the underground substation transformer cooling system according to the embodiment of the present invention will be described.

  In the description, one model is set for the dry-type cooler 11 and the transformer (cooled body) 3. That is, the location of the underground substation is Tokyo, and the heat exchanger rated logarithmic average temperature difference of the dry cooler 11 and the iron loss ratio of the transformer (cooled body) 3 are set as follows.

<Dry cooler 11>
Cooling air temperature (inlet air temperature) Tai: 18 ° C. (design temperature of the dry cooler 11)
Outlet air temperature Tao: Tao = Tai + 18 = 18 + 18 = 36 ° C.
Circulating water (cooling water) inlet temperature Twi: 48 ° C
Circulating water (cooling water) outlet temperature Two: 58 ° C
Heat exchanger rated logarithm average temperature difference = {(58-36)-(48-18)} / ln {(58-36) / (48-18)}
= 25.8 ° C

<Transformer 3>
Capacity: 300MVA (gas insulated transformer)
Rated iron loss (no load loss): 120kW
Rated copper loss (load loss): 1710 kW
Rated loss: 1830kW
Iron loss ratio: 120/1830 = 0.0656

  Using the fact that the heat transfer performance of the dry cooler 11 is proportional to the logarithmic average temperature difference, when the cooling air temperature (dry bulb temperature 18 ° C.) is exceeded, how much is the load factor of the transformer 3 under the above setting conditions? It will be explained whether it is possible to cope with only the dry cooler 11 having the above set conditions (dry operation) until it becomes.

  FIG. 5 is an explanatory diagram (graph) showing the relationship between the cooling air temperature (inlet air temperature) and the load factor and heat transfer performance when the dry bulb temperature exceeds 18 ° C., derived from the equations (1) to (6). It is. In addition, the code | symbol L1 is a graph which shows a load factor, the code | symbol L2 is a graph which shows heat quantity ratio (heat transfer performance), and the graph (solid line) of L1 and L2 makes the numerical value of 18 degreeC one.

  In the graph illustrated in FIG. 5, the heat transfer performance (corresponding to the graph L2) decreases as the temperature rises above 18 ° C., but the load factor (corresponding to the graph L1) that can be handled only by the dry cooling means. ) Will also decline. In Tokyo where underground substations are installed, the monthly average temperature in August, the highest month of the year, is 27.4 ° C. The American Society of Heating, Refrigerating (ASHHRAE) and Air-Conditioning Engineers), which is the design standard for cooling, has a yearly excess risk factor of 0.4% and average matched dry bulb temperature (0.4% MCDB) is 33.2 ° C.

  The load factor shown by the graph L1 illustrated in FIG. 5 is about 82% in the case of 27.4 ° C., which corresponds to the average temperature in August in Tokyo, and the ASHRAE year standard excess risk rate 0.4% average in Tokyo The matching dry bulb temperature (0.4% MCDB) of 33.2 ° C. is about 65%. Therefore, in the first underground substation transformer cooling system 30A (FIG. 2) and the first underground substation transformer cooling device 10A (FIGS. 1 and 2), which is the secondary cooling means, the dry bulb temperature 33.2. Even at ° C., it can be said that it can cope with the amount of heat generated when the load factor is about 65% in the dry operation (the blower 121 is on and the watering pump 122 is off).

  Although the load factor differs somewhat at each substation, all are generally said to be 60-80%. Therefore, if it can handle the amount of heat generated when the load factor is 80%, it can be transformed almost all year round. The vessel 3 can be continuously cooled. Therefore, in the first underground substation transformer cooling system 30A (FIG. 2), the first underground substation transformer cooling device 10A is operated almost all year round without wet operation (with the watering pump 122 turned on). The transformer 3 can be continuously cooled.

  In addition, the first underground substation transformer cooling system 30A has a load without a wet operation (with the blower 121 turned on and the watering pump 122 turned on) even at a dry bulb temperature of 33.2 ° C. (in a dry operation). Since it can cope with the amount of heat generated at a rate of about 65%, wet operation is unnecessary for most of the time throughout the year, and the timing when wet operation is required is very limited throughout the year (it is zero in some years).

  If the wet operation in the first underground substation transformer cooling device 10A is substantially 0 (zero), the replenishment moisture used in the open type cooling tower 12 is set to almost 0 (ie, 100). % Savings. The open-type cooling tower 12 is activated even when the temperature condition is high (100%) and extremely high (40 ° C.), for example, when the load factor exceeds 80%. By doing so, it is possible to cool the transformer 3 within the design temperature. That is, the open-type cooling tower 12 can be installed in the position of a preliminary (emergency) cooling means in preparation for an extremely rare case of high temperature and high load.

  Even if the operation of the open type cooling tower 12 is necessary, the use is limited to a very short time, so the blow-down water can be minimized. The sewerage bill can also be saved significantly.

  Furthermore, the first underground substation transformer cooling device 10 </ b> A has the dry cooler 11 placed vertically at the outside air intake of the open cooling tower 12, and the dry cooler 11 and the open cooling tower 12 are integrated. Since it is configured, the installation area can be greatly reduced (about half) compared to the case where the dry cooler 11 and the open type cooling tower 12 are individually installed.

  In this way, wet operation is applied to the amount of heat generated when the load factor is 80% under the monthly average temperature conditions of the highest temperature month throughout the year (for example, 27.4 ° C, which is the monthly average temperature in August in Tokyo). Since the underground substation transformer cooling system according to the embodiment of the present invention that can be handled by dry operation without being implemented can substantially reduce water to be used, the annual water bill (water supply and sewerage) It can be said that it is extremely useful in that the transformer cooling in the first and second operation stages can be continued even if water breaks off due to the occurrence of a large-scale disaster.

  According to the first underground substation transformer cooling device 10A, the first underground substation transformer cooling system 30A, and the first underground substation transformer cooling method, wet operation (spread water in the open cooling tower 12) Can be limited to a very short time (depending on the outside temperature and transformer load, the operation time can be reduced to zero). Can save water (up to 100%). Therefore, water charges (water supply charges and sewer charges) required when operating the first underground substation transformer cooling device 10A and the first underground substation transformer cooling system 30A are greatly increased (up to 100%). ) Can be reduced.

  Further, in the first underground substation transformer cooling system 30A, the secondary cooling means, that is, the time during which the first underground substation transformer cooling device 10A uses water is extremely rare at the time of high temperature and high load. In some cases, the amount of water required for operation of the first underground substation transformer cooling device 10A is limited to a small amount of water (minimum 0 (zero)). can do. Therefore, even if a water outage occurs due to the occurrence of a large-scale disaster or the like, the first underground substation transformer cooling system 30A performs the dry operation of the first underground substation transformer cooling device 10A so that the transformer 3 Cooling can be continued.

  In addition, it can be assumed that a water outage will occur due to the occurrence of a large-scale disaster in a very short period of time throughout the year when wet operation is required. The rate is assumed to be lower than normal due to reasons such as transformer load limitation or the inability to use the load facility due to the occurrence of a large-scale disaster. Therefore, even if a water outage occurs due to the occurrence of a large-scale disaster in a very short time throughout the year when wet operation is required, without performing wet operation (operating the blower 121 and operating the watering pump 122), As long as the dry operation (operating the blower 121 without operating the watering pump 122) is performed in advance, sufficient cooling capacity to continue cooling the transformer 3 can be ensured.

  Further, in the first underground substation transformer cooling device 10A and the first underground substation transformer cooling system 30A, the time required for the wet operation for operating the watering pump 122 in the open type cooling tower 12 is set to the annual Therefore, it is possible to limit the time to a limited time, so that scale (scale) adhesion hardly occurs in the open type cooling tower 12, and maintenance such as cleaning becomes simple. Furthermore, since watering in the open cooling tower 12 is unnecessary for a long period of time (regularly), it is not necessary to take preventive measures for legionellosis, and the labor and cost required for the preventive measures for legionellosis can be reduced.

  Further, in the first underground substation transformer cooling system 30A, the period during which the wet operation is not performed, that is, the period in which the wet cooler (open cooling tower 12) is disconnected from the cooling system 70 occupies most of the year. Therefore, it is possible to clean the open cooling tower 12 during the period, remove the scale when it slightly occurs, and perform necessary maintenance.

  Furthermore, in the first underground substation transformer cooling device 10A and the first underground substation transformer cooling system 30A, the cooling system 70 passes through the main system through which the primary cooling means 72 flows and the open cooling tower 12. Since the water is separated from the sub-system, the quality of the circulating water flowing through the main system can be prevented from deteriorating.

  In addition, since the first underground substation transformer cooling device 10A and the first underground substation transformer cooling system 30A can form a wet cooler with the open type cooling tower 12, the wet type cooler is a closed type cooling tower. Compared with the case (for example, the second underground substation transformer cooling device 10B), the wet cooler can be reduced in size, which is advantageous in terms of ease of maintenance and cost.

[Second Embodiment]
FIG. 6 shows an underground substation transformer cooling device (hereinafter referred to as a “second underground substation transformer cooling device”) which is an example of an underground substation transformer cooling device according to the second embodiment of the present invention. .) Device configuration diagram schematically showing 10B, FIG. 7 is an example of an underground substation transformer cooling system (hereinafter referred to as “the substation transformer cooling system”) according to the second embodiment of the present invention. This is a system configuration diagram schematically showing a cooling system 70 centering on a cooling facility of 30B (shown in FIG. 7 is one bank). .

  In the second underground substation transformer cooling device 10B, the heat exchanger 13 installed in the first underground substation transformer cooling device 10A is installed with respect to the first underground substation transformer cooling device 10A. There are some differences, such as not.

  Further, the second underground substation transformer cooling system 30B is applied to the first underground substation transformer cooling system 30A, and the applied secondary cooling means is the first underground substation transformer cooling device 10A. The second substation transformer cooling device 10B is applied instead of the second substation transformer cooling device 10B, but the other points are not substantially different. Therefore, in this embodiment, the difference between the second underground substation transformer cooling device 10B and the first underground substation transformer cooling device 10A will be mainly described, and the first underground substation transformer cooling device 10A will be described. Constituent elements that are not substantially different from the constituent elements of FIG.

  As illustrated in FIG. 6, the second underground substation transformer cooling device 10 </ b> B is similar to the first underground substation transformer cooling device 10 </ b> A. Wet cooling means that is operated in a very short period such as when the temperature is high is integrated. In the second underground substation transformer cooling device 10B, at least one dry cooler 11 such as two (FIG. 6), for example, is used as the dry cooling means, and one (FIG. 6) is provided as the wet cooling means. Are installed at the outside air intake port of the hermetic cooling tower 14 which is an example of at least one wet cooler.

  In the second underground substation transformer cooling device 10 </ b> B, by operating the blower 141 as a common blower installed in the upstream stage of the closed cooling tower 14, the outside air 1 is first brought into the dry cooler 11. After being introduced and ventilated through the heat transfer section 111 of the dry cooler 11, it is guided to the inside of the closed type cooling tower 14 without being exhausted outside the apparatus by the duct 112, and is exhausted from the inside of the closed type cool tower 14 to the outside.

  On the other hand, the circulating water introduced into the second underground substation transformer cooling device 10 </ b> B is first introduced into each dry cooler 11, and heat exchange (heat radiation) is performed in the heat transfer unit 111. The circulating water after passing through each dry cooler 11 is subsequently introduced into a closed cooling tower 14 (wet cooler).

  In the hermetic cooling tower 14, the circulating water passes through the heat transfer unit 144 through which sprinkled water is sprinkled from the water sprinkling unit 143 as necessary. When the heat transfer unit 144 is sprayed, the circulating water flowing through the heat transfer unit 144 is cooled (heat radiation) by the latent heat of evaporation of the spray water. The circulating water after passing through the sealed cooling tower 14 is carried to the outside of the second underground substation transformer cooling device 10B.

In the second underground substation transformer cooling device 10B, as in the first underground substation transformer cooling device 10A, the operating state is
(1) Both the dry cooler 11 and the wet cooler (sealed cooling tower 14) are off, that is, the blower 141 and the watering pump 142 are stopped.
(2) The dry cooler 11 is on and the wet cooler (sealed cooling tower 14) is off, that is, the blower 141 is in operation and the watering pump 142 is stopped.
(3) Both the dry cooler 11 and the wet cooler (sealed cooling tower 14) are on, that is, the blower 141 and the watering pump 142 are in operation.
It can be switched to three stages.

  In other words, the second underground substation transformer cooling device 10B has the above (1) as the first operation stage (dry operation), (2) as the second operation stage (dry operation), and the above, respectively. (3) is the third operation stage (wet operation), and the operation stage can be switched in three stages from the first operation stage to the third operation stage, depending on the required cooling capacity ( The cooling stage (operation stage) of 1) to (3) can be selected.

  Therefore, in the second underground substation transformer cooling device 10B, as in the first underground substation transformer cooling device 10A, the dry cooler 11 serves as a means for exchanging heat with the circulating water flowing through the primary cooling means 72. Is used on a regular basis (mainly), and only when the cooling capacity needs to be further increased (during high temperature and high load), the sealed cooling tower 14 as a wet cooler using water for cooling is reserved. Flexible operation is possible.

  Further, the second underground substation transformer cooling device 10B is applied as a secondary cooling means of a general underground substation transformer cooling system, similarly to the first underground substation transformer cooling device 10A and the like. Can do. As illustrated in FIG. 7, in the second underground substation transformer cooling system 30 </ b> B including the second underground substation transformer cooling device 10 </ b> B, the circulating water fed from the circulating water pump 71 is used as a dry cooler. 11, the heat transfer section 144 of the hermetic cooling tower 14, and the primary cooling means 72 are sequentially passed, and then returned to the circulating water pump 71 and sent out from the circulating water pump 71 again.

  The second underground substation transformer cooling system 30B cools the transformer 3 by dissipating heat generated in the transformer 3 in the process in which the circulating water sent from the circulating water pump 71 circulates in the cooling system 70. (Heat radiation).

  In the second underground substation transformer cooling system 30B, the cooling system 70 through which the circulating water sent from the circulating water pump 71 circulates is not limited to the flow path illustrated in FIG. That is, the second underground substation transformer cooling system 30B can be configured using a cooling system 70 having a flow path configuration different from that of the cooling system 70 illustrated in FIG. Subsequently, another example of the second underground substation transformer cooling system 30B is illustrated in FIG.

  FIG. 8 is a system configuration diagram schematically showing a modification of the underground substation transformer cooling system 30B (one bank is shown in FIG. 8) and a cooling system 70 centering on cooling equipment.

  The second underground substation transformer cooling system 30B illustrated in FIG. 8 is different from the second underground substation transformer cooling system 30B illustrated in FIG. A flow path connecting the input end of the means 72 and the valve 19 and a flow path connected to the valve 19 and the output ends of the two dry coolers 11 are further provided. Here, the valves 17 and 18 are normally closed valves that are normally closed and opened in an emergency such as a high temperature and high load. The valve 19 is a normally open valve that is normally open and closed in an emergency such as a high temperature and high load. The valves 17, 18, and 19 are constituted by electric valves or manual valves, and in the case of an electric valve, the opening / closing can be automatically switched based on an open command or a close command from the control device 31 </ b> B.

  In the second underground substation transformer cooling system 30B illustrated in FIG. 8, the first and second operation stages are operated in the normal state shown in FIG. Therefore, the circulating water sent out from the circulating water pump 71 is subjected to heat exchange (heat radiation) in each dry cooler 11 and then passes through the valve 19 that is open without flowing into the sealed cooling tower 14 to be the primary cooling means. Return to the circulating water pump 71 through 72. The circulating water that has returned to the circulating water pump 71 is sent again from the circulating water pump 71 to each dry cooler 11.

  In the third operation stage, the operation is performed in an emergency state, that is, in a state where the valves 17 and 18 are open and the valve 19 is closed. Therefore, the circulating water sent out from the circulating water pump 71 is subjected to heat exchange (heat radiation) in each dry cooler 11, and further flows into the sealed cooling tower 14 and sprayed water is sprinkled by the sprinkling unit 143. Heat exchange (heat radiation) is performed in the heat transfer section 144. The circulating water cooled (radiated) by the dry cooler 11 and the closed cooling tower 14 returns to the circulating water pump 71 through the primary cooling means 72. The circulating water that has returned to the circulating water pump 71 is sent again from the circulating water pump 71 to each dry cooler 11.

  As described above, in the second underground substation transformer cooling system 30B illustrated in FIG. 8, in addition to the on / off switching of the blower 141 and the watering pump 142, switching of the open / close states of the valves 17 to 19 is performed. Thus, the flow path through which the circulating water flows is switched, and the three cooling stages can be switched and operated similarly to the second underground substation transformer cooling system 30B exemplified in FIG.

  If it is desired to flow the circulating water after passing through the two dry coolers 11 more surely into the closed type cooling tower 14, the valve 19 is not omitted and is installed in the third operation stage. When the underground substation transformer cooling device 10B is operated, the valve 19 may be closed.

  Regarding the underground substation transformer cooling method using the second underground substation transformer cooling system 10B (hereinafter referred to as “second underground substation transformer cooling method”), the first underground substation transformer cooling method is used. Although the system to be used is different from the method for cooling the substation transformer, the steps to be performed are substantially the same. Therefore, the second substation transformer will be described with the explanation of the first substation transformer cooling method. Description of the cooling method is omitted.

  According to the second underground substation transformer cooling device 10B, the second underground substation transformer cooling system 30B, and the second underground substation transformer cooling method configured as described above, the first underground substation transformer cooling method is provided. Station transformer cooling device 10A, first underground substation transformer cooling system 30A, and the same effect as the first underground substation transformer cooling method, that is, drastically (up to 100%) water saving compared to the prior art There are effects such as being able to.

[Third Embodiment]
FIG. 9 shows an underground substation transformer cooling device (hereinafter referred to as “third underground substation transformer cooling device”), which is an example of an underground substation transformer cooling device according to the third embodiment of the present invention. .) FIG. 10 is a schematic diagram of an apparatus configuration of 10C, and FIG. 10 is an example of an underground substation transformer cooling system (hereinafter referred to as “an underground substation transformer cooling system”) according to a third embodiment of the present invention. This is a system configuration diagram schematically showing a cooling system 70 centering on a cooling facility of 30C (shown in FIG. 9 is one bank). .

  In the third underground substation transformer cooling device 10C, the heat exchanger 13 installed in the first underground substation transformer cooling device 10A is installed with respect to the first underground substation transformer cooling device 10A. There are some differences, such as not.

  In addition, the third underground substation transformer cooling system 30C is applied to the first underground substation transformer cooling system 30A. Although the difference is that the third underground substation transformer cooling device 10C is applied instead of the above, the other points are not substantially different. Therefore, in this embodiment, the difference between the third underground substation transformer cooling device 10C and the first underground substation transformer cooling device 10A will be mainly described, and the first underground substation transformer cooling device 10A will be described. Constituent elements that are not substantially different from the constituent elements of FIG.

  As illustrated in FIG. 9, the third underground substation transformer cooling device 10 </ b> C is similar to the first underground substation transformer cooling device 10 </ b> A in that it has a dry cooling means and a high level downstream of the dry cooling means. Wet cooling means that is operated in a very short period such as when the temperature is high is integrated. In the third underground substation transformer cooling device 10C, at least one dry cooler 11 such as two (FIG. 9), for example, as the dry cooling means, for example, one (FIG. 9) as the wet cooling means, etc. Are installed in the outside air intake port of the open type cooling tower 12 which is an example of at least one wet cooler.

  In the third underground substation transformer cooling device 10 </ b> C, the outside air 1 is first brought into the dry cooler 11 by operating the blower 121 as a shared blower installed in the upstream stage of the open cooling tower 12. After being introduced and ventilated through the heat transfer section 111 of the dry cooler 11, it is guided to the inside of the open type cooling tower 12 without being exhausted outside the apparatus by the duct 112, and exhausted from the inside of the open type cooling tower 12 to the outside.

  Further, in the third underground substation transformer cooling device 10C, the valves 21, 22, 23 and the valve 24 are installed downstream of the auxiliary water tank 73 in the flow path through which the circulating water (cooling water) circulates. A normal flow path for passing water through the dry cooler 11, the valve 23 and the valve 24, and an emergency flow path for passing water through the dry cooler 11, the valves 21, 22 and the open cooling tower 12 are provided as the valve 21. , 22 and 23 can be switched.

  Here, the valves 21 and 22 are normally closed valves that are normally closed and open in an emergency such as a high temperature and high load, and the valves 23 and 24 are normally open and an emergency such as a high temperature and high load. It is a normally open valve that is sometimes closed.

  Accordingly, in the third underground substation transformer cooling device 10C, since the valves 21 and 22 are closed and the valves 23 and 24 are opened in the normal time, the third underground substation transformer cooling device 10C flows into the third underground substation transformer cooling device 10C. The cooled water is cooled by the dry cooler 11 and then flows through the valve 23 and flows out of the apparatus.

  On the other hand, in the event of an emergency, since the valves 21 and 22 are open and the valve 23 is closed, the cooling water flowing into the third underground substation transformer cooling device 10C is dry-cooled. After being cooled by the vessel 11, the water is introduced into the open cooling tower 12 through the valves 21 and 22 and sprinkled. The cooling water sprayed in the open type cooling tower 12 is cooled by latent heat of evaporation when it is directly opened to the atmosphere and evaporated. The cooling water cooled in the open type cooling tower 12 is sent out of the apparatus from the open type cooling tower 12 using the atmospheric pressure which acts, for example.

  In the third underground substation transformer cooling system 30C provided with the third underground substation transformer cooling device 10C configured as described above as the secondary cooling means, the primary cooling means 72, the circulating water pump 71, The first underground substation in that circulating water (cooling water) flows in a flow path configured by connecting the third underground substation transformer cooling device 10C (secondary cooling means). It is comprised similarly to the cooling system 70 of other underground substation transformer cooling systems, such as a station transformer cooling system 10A.

  In the third underground substation transformer cooling system 30C, the operation of the third underground substation transformer cooling device 10C as the secondary cooling means is controlled by the control device 31C. For example, the control device 31C switches the on / off of the blower 121 and the water spray pump 122 and the opening and closing of the valves 21 to 24 based on the temperature information (circulation water temperature TE) acquired by the thermometer 75. 3 substation transformer cooling device 10C can be operated in any one of the first operation stage to the third operation stage (cooling stage).

  The above-described third underground substation transformer cooling system 30C is an example in which the valves 21 to 24 are automatically opened and closed in response to a control command (open command or close command) from the control device 31C. Although it is an example supposing the case where the valves 21, 22, 23, and 24 are motor-driven valves, the valves 21 to 23 may be manual valves and may be configured to be manually opened and closed by the user. In this case, switching between the second operation stage and the third operation stage is performed manually.

  An underground substation transformer cooling method (hereinafter, referred to as “third underground substation transformer cooling method”) using the third underground substation transformer cooling system 10C will be described.

  The third underground substation transformer cooling method is substantially similar to the first underground substation transformer cooling method although the system to be used is different. However, since the third underground substation transformer cooling method uses a third underground substation transformer cooling device 10C different from the first underground substation transformer cooling device 10A, the steps shown in FIG. The detailed processing contents in S7 are different.

  Specifically, the operation stage (cooling stage) of the first underground substation transformer cooling device 10A is controlled by controlling on / off of the blower 121 (FIG. 2) and the watering pump 122 (FIG. 2). In contrast to the first underground substation transformer cooling method, which is switched to any one of the first operation stage to the third operation stage, in the third underground substation transformer cooling method, the blower 121 (FIG. 10) is turned on. / Off and the opening and closing of the valves 21, 22, 23, 24 (FIG. 10) (switching of the flow path through which the circulating water flows) to control the operation stage (cooling) of the third underground substation transformer cooling device 10C Step) is switched to one of the first operation stage to the third operation stage.

  According to the third underground substation transformer cooling device 10C, the third underground substation transformer cooling system 30C, and the third underground substation transformer cooling method configured as described above, the first underground substation transformer cooling method is provided. Station transformer cooling device 10A, first underground substation transformer cooling system 30A, and the same effect as the first underground substation transformer cooling method, that is, drastically (up to 100%) water saving compared to the prior art There are effects such as being able to.

  Further, since the third underground substation transformer cooling device 10C does not require the watering pump 122 (FIG. 2) or the watering pump 144 (FIGS. 7 and 8), the third underground substation transformer cooling device 10C and The configuration of the third underground substation transformer cooling system 30C is more than the configuration of the first and second underground substation transformer cooling devices 10A and 10B and the first and second underground substation transformer cooling systems 30A and 30B. It can be simplified.

  As described above, according to the first to third underground substation transformer cooling devices 10A to 10C, the first to third underground substation transformer cooling systems 30A to 30C, and the first to third underground substation transformer cooling methods. Since the wet operation time can be limited to a limited time throughout the year (depending on the outside temperature and transformer load, the operation time can be reduced to zero). %) Can save water. Therefore, it is possible to greatly reduce water bills (water supply bills and sewer bills) required when operating the first to third underground substation transformer cooling systems 30A to 30C.

  Further, in the first to third underground substation transformer cooling systems 30A to 30C, even if a water outage occurs due to the occurrence of a large-scale disaster or the like, the first to third underground substation transformers as secondary cooling means Since the water required for operating the condenser cooling devices 10A to 10C is very little, the cooling of the transformer 3 can be continued. That is, it is possible to provide a transformer cooling device, a transformer cooling system, and a transformer cooling method for an underground substation that is resistant to disaster.

  Further, in the first to third underground substation transformer cooling systems 30A to 30C, the time required for wet operation is very small throughout the year (zero depending on the year). Almost no scale (scale) adheres to the cooling means. In addition, since there is no need for wet operation over a long period of time (regularly), it is not necessary to take preventive measures for legionellosis, and the labor and cost required for preventive measures for legionellosis can be reduced.

  Moreover, in the 1st-3rd underground substation transformer cooling system 30A-30C, the period when the wet operation is not carried out, ie, the period when the wet coolers (cooling towers 12 and 14) are disconnected from the cooling system 70 is annual. Therefore, the open-type cooling tower 12 and the closed-type cooling tower 14 can be cleaned, the scale can be removed if necessary, and necessary maintenance can be performed during this period.

  Further, the first to third underground substation transformer cooling devices 10A to 10C are integrated by placing the dry cooler 11 on the outside air intake port of the open type cooling tower 12 or the closed type cooling tower 14 and integrating them. Therefore, the installation area of the cooling facility in the first to third underground substation transformer cooling systems 30A to 30C can be reduced (about half of the conventional underground substation transformer cooling system) It can be made into a space.

  Therefore, in general, in the underground substations in urban areas where it is difficult to secure a large installation space as the cooling facilities tend to become large-scale, if the same installation space as the current situation can be secured, not only at the time of new installation but also at the time of renovation The first to third underground substation transformer cooling systems 30A to 30C can also be applied.

  Furthermore, the first to third underground substation transformer cooling devices 10A to 10C are connected to the outside air intake of the open type cooling tower 12 or the closed type cooling tower 14 (the outside of the open type cooling tower 12 or the closed type cooling tower 14). ) Is provided with the dry cooler 11, it is possible to reliably avoid the situation in which the sprayed water sprayed inside the open type cooling tower 12 or the closed type cooling tower 14 reduces the heat exchange efficiency of the dry cooler 11. be able to.

  More specifically, it is known that the cooling tower includes a cooling device in which a dry cooler is arranged, that is, a cooling device in which a dry cooler and a wet cooler are integrated. In the cooling device in which the dry cooler is arranged inside the cooling tower, due to its structure, a part of the sprayed water sprayed inside the cooling tower is rolled up and adheres to the fins of the dry cooler. Unavoidable. Since the sprayed water sprayed in the cooling tower is concentrated by evaporation of salts such as calcium (Ca) and magnesium (Mg), the sprayed water adhering to the fins solidifies on the fins and becomes a scale. Accumulate in fins. If the scale accumulates on the fins, the air flow in the dry cooler is hindered, and the heat exchange efficiency in the dry cooler decreases.

  On the other hand, in the first to third underground substation transformer cooling devices 10A to 10C, the dry cooler 11 is installed at the outside air intake that is outside the open type cooling tower 12 or the closed type cooling tower 14. Therefore, the scale does not accumulate in the fins of the dry cooler 11, and a decrease in the heat exchange efficiency of the dry cooler 11 due to the scale accumulation can be reliably avoided.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be implemented in various forms other than the above-described examples in the implementation stage, and within the scope not departing from the gist of the invention. Various omissions, additions, replacements, and changes can be made. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

1 Outside air 3 Transformer (cooled body)
10A, 10B, 10C First, second and third underground substation transformer cooling device 11 Dry cooler (dry cooling means)
111 Heat transfer section (first heat exchange section)
112 Duct 12 Open cooling tower (wet cooling means, second heat exchanging section)
121 Blower 122 Sprinkling Pump 123 Sprinkling Unit 13 Heat Exchanger (Second Heat Exchanger)
14 Closed cooling tower (wet cooling means)
141 Blower 142 Sprinkling pump 143 Sprinkling part 144 Heat transfer part (second heat exchange part)
17, 18, 21, 22 Valve (Normally closed valve)
19, 23, 24 valves (normally open)
30A, 30B, 30C 1st, 2nd, 3rd substation transformer cooling system 31A, 31B, 31C Controller 70 Cooling system 71 Circulating water pump 72 Primary cooling means 73 Makeup water tank 75 Thermometer L1 Load factor L2 Heat ratio

Claims (8)

The circulating water is provided on a path through which the circulating water circulates, and is located away from the primary cooling means for removing heat generated by the transformer installed in the underground substation by exchanging heat with the circulating water. A transformer cooling device that is installed on a circulating path and cools hot water that is circulating water after passing through the primary cooling means;
By supplying the taken-out outside air as cold heat to the first heat exchange section that exchanges heat with the circulating water supplied into the apparatus, at least one capable of dry operation without using water for cooling at high temperature and high load More than a dry cooler ,
Cooling is supplied to the second heat exchanger that exchanges heat with the circulating water after passing through the dry cooler using the water for cooling at the time of the high temperature and high load, thereby cooling the circulating water. At least one open cooling tower capable of wet operation;
The at least one dry cooler , and a common air blowing means for generating an air flow for sequentially passing the open cooling tower ,
The second heat exchanger is disposed outside the open-type cooling tower, and the circulating water after passing through the at least one dry cooler is passed to the primary side to pass the secondary side. Circulated through the open-type cooling tower and the second heat exchanger, and is configured to allow the sprayed water to be released to the atmosphere sprayed by the open-type cooling tower to pass through.
The at least one open type cooling tower is configured to be capable of switching the wet operation on and off, and configured to switch the wet operation on at the time of the high temperature and high load. Transformer cooling system for underground substation. The circulating water is provided on a path through which the circulating water circulates, and is located away from the primary cooling means for removing heat generated by the transformer installed in the underground substation by exchanging heat with the circulating water. A transformer cooling device that is installed on a circulating path and cools hot water that is circulating water after passing through the primary cooling means;
By supplying the taken-out outside air as cold heat to the first heat exchange section that exchanges heat with the circulating water supplied into the apparatus, at least one capable of dry operation without using water for cooling at high temperature and high load More than a dry cooler,
At least one open type cooling tower capable of a wet operation for cooling the circulating water after passing the dry cooler;
The at least one dry cooler, and a common air blowing means for generating an air flow for sequentially passing the open cooling tower,
A first flow path for supplying the circulating water after passing through the at least one dry cooler to the outside; and the at least one circulating water after passing through the at least one dry cooler. A second flow path for supplying the inside of the open cooling tower or higher, a first valve for opening and closing the first flow path, and a second valve for opening and closing the second flow path. And
Wherein at least one or more open cooling tower, closing the first valve, the said circulating water supplied by opening the second valve opened to the atmosphere in the tower, the latent heat of vaporization after air opening Supplying the cooled circulating water to the outside;
The at least one open type cooling tower is configured to be capable of switching the wet operation on and off, and configured to switch the wet operation on at the time of the high temperature and high load. Transformer cooling system for underground substation. 3. The transformer cooling device for an underground substation according to claim 2, wherein the first valve and the second valve are configured by an electric valve that opens and closes based on an open command or a close command received. The transformer cooling device for an underground substation according to any one of claims 1 to 3 , wherein a plurality of the dry coolers are provided for one of the open cooling towers . Further comprising a control device for switching on and off of the dry operation and on and off of the wet operation;
The control device determines whether the dry operation should be turned on and whether the wet operation should be turned on based on the temperature of the circulating water, and issues a command based on the determination result to the at least Transformer cooling of an underground substation according to any one of claims 1 to 4 , characterized in that it is configured to feed one or more dry coolers and the at least one open cooling tower . apparatus. The control device includes a first threshold value for determining whether to switch the dry operation from off to on, and a value equal to or less than the first threshold value for determining whether to switch the dry operation from on to off. A second threshold for determining whether to switch the wet operation from off to on, and the third threshold for determining whether to switch the wet operation from on to off And a fourth threshold value is set,
The control device compares whether the temperature of the circulating water and the load factor of the underground substation with the threshold value to determine whether the dry operation should be turned on and whether the wet operation should be turned on. 6. The transformer cooling device for an underground substation according to claim 5 , wherein the transformer cooling device is configured to determine whether or not the substation is installed. Primary cooling means provided on a path through which the circulating water circulates and removing heat generated from the transformer installed in the substation by exchanging heat with the circulating water, and the primary cooling means Transformer cooling of an underground substation comprising secondary cooling means installed on a path where the circulating water circulates at a distant position and cools hot water that is circulating water after passing through the primary cooling means System,
7. A transformer cooling system for an underground substation, wherein the transformer cooling device for an underground substation according to claim 1 is applied as the secondary cooling means. It is a transformer cooling method of an underground substation using the transformer cooling device according to any one of claims 1 to 6 .
Based on the measured temperature of the circulating water, it is determined whether the high temperature / high load or the normal operation is not the high temperature / high load, and the determination result is the normal operation Turning on the dry operation and turning off the wet operation ;
And a step of turning on the dry operation and turning on the wet operation when the determination result is at the time of the high temperature and high load.

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