Water spraying device and water spraying method

Abstract

To provide a sprinkling device that can reduce the amount of water to be discharged downward without being evaporated by a sprinkling mat.SOLUTION: A sprinkling device cools a heat exchanger by using air from which heat of vaporization has been removed in association with evaporation of water from a sprinkling mat wetted with water, and comprises a lower end detection unit for detecting the position of a lower end of a wetted region of the sprinkling mat, and a control unit for controlling the amount of water to be supplied to the sprinkling mat on the basis of the position of the lower end of the wetted region.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a watering device and a watering method.

Background Art

[0002] Conventionally, there is known a watering device that reduces a condensation load by dripping water onto a watering mat installed in front of a heat exchanger of a refrigerator, and using air from which heat of vaporization has been taken away as the water on the watering mat evaporates (see, for example, Patent Document 1). The watering device described in Patent Document 1 measures the temperature outside the watering mat (the side opposite to the heat exchanger with respect to the watering mat), and supplies water to the watering mat when the measured temperature is equal to or higher than a set value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration described in Patent Document 1, since the water supply amount is adjusted based only on the temperature outside the watering mat, there is a possibility that the amount of water discharged downward without evaporating on the watering mat increases.

[0005] An object of the present disclosure is to provide a watering device and a watering method capable of reducing the amount of water discharged downward without evaporating on the watering mat.

Means for Solving the Problems

[0006] The water sprinkling device of the present disclosure is a water sprinkling device that cools a heat exchanger with air whose latent heat of vaporization is taken away due to the evaporation of water from a water-wetted sprinkling mat, and includes a dry bulb temperature detection unit that detects the dry bulb temperature and a wet bulb temperature detection unit that detects the wet bulb temperature, a lower end detection unit that detects the position of the lower end of the wetted area of the sprinkling mat based on the dry bulb temperature and the wet bulb temperature, and a control unit that adjusts to reduce the amount of water supplied to the sprinkling mat based on the position of the lower end of the wetted area. The dry-bulb temperature detection unit is an inner dry-bulb temperature detection unit disposed between the water spray mat and the heat exchanger, the wet-bulb temperature detection unit is disposed at a position on the opposite side of the heat exchanger with respect to the water spray mat, and the lower-end detection unit detects the position of the lower end of the wetted region based on the relationship that the lower the temperature difference between the dry-bulb temperature detected by the inner dry-bulb temperature detection unit and the wet-bulb temperature detected by the wet-bulb temperature detection unit, the closer the position of the lower end of the wetted region is to the inner dry-bulb temperature detection unit.

[0007] The water sprinkling method of the present disclosure is a water sprinkling method performed by a water sprinkling device that cools a heat exchanger with air whose latent heat of vaporization is taken away due to the evaporation of water from a water-wetted sprinkling mat. The water sprinkling device An inner dry-bulb temperature detection unit disposed between the water spray mat and the heat exchanger, a wet-bulb temperature detection unit disposed at a position on the opposite side of the heat exchanger with respect to the water spray mat, a lower-end detection unit, and a control unit, wherein the inner dry-bulb temperature detection unit detects the dry bulb temperature detects, and the wet-bulb temperature detection unit and the wet bulb temperature, The lower-end detection unit is the one detected by the inner dry-bulb temperature detection unit and based on the dry bulb temperature detected by the wet-bulb temperature detection unit and the wet bulb temperature Based on the relationship that the lower the temperature difference therebetween, the closer the position of the lower end of the wetted region is to the inner dry-bulb temperature detection unit detects the position of the lower end of the wetted area of the sprinkling mat, The control unit and adjusts to reduce the amount of water supplied to the sprinkling mat based on the position of the lower end of the wetted area.

Advantages of the Invention

[0008] According to the water sprinkling device and the water sprinkling method of the present disclosure, it is possible to reduce the amount of water discharged downward without evaporating on the sprinkling mat.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0010] [Embodiment] An embodiment of the present disclosure will be described.

[0011] <Configuration of a refrigerant cooling device having a sprinkling device> First, the configuration of a refrigerant cooling device having a sprinkling device in an embodiment of the present disclosure will be described. FIG. 1 is a front view of the refrigerant cooling device. FIG. 2 is a side view of the refrigerant cooling device. FIG. 3 is a block diagram of the control system of the sprinkling device. Note that the number of each constituent member of the refrigerant cooling device is not limited to the number exemplified below.

[0012] The refrigerant cooling device 1 shown in FIGS. 1 and 2 cools the refrigerant compressed by a compressor of a refrigeration device (not shown). The refrigerant cooling device 1 includes a cooling unit 2 and an auxiliary cooling device 3.

[0013] The cooling unit 2 includes a main body 21 and two heat exchangers 22.

[0014] The main body 21 houses two heat exchangers 22. The main body 21 is formed in a rectangular box shape. Openings 211 are formed in the right side wall (right side wall) and the left side wall (left side wall) of the main body 21 in FIG. 1, respectively. Through the openings 211, the air outside the main body 21 is introduced into the inside of the main body 21.

[0015] A fan 23 is disposed on the upper wall of the main body 21. The fan 23 is driven based on the control of a unit control section (not shown). The fan 23 discharges the air inside the main body 21 upward of the main body 21.

[0016] The heat exchanger 22 is a so-called air-cooled heat exchanger, which performs heat exchange between the refrigerant compressed by the compressor and the air existing around the heat exchanger 22, and sends the cooled refrigerant after heat exchange to the evaporator via the expansion valve of the refrigeration device. The object to be cooled by the refrigeration device is cooled by the heat exchange between the refrigerant sent to the evaporator and the air existing around the evaporator. The two heat exchangers 22 are arranged at positions respectively facing the openings 211 on the right side wall and the left side wall of the main body 21. The two heat exchangers 22 are inclined so that the distance between the upper ends is longer than the distance between the lower ends when viewed from the front side (the front side in FIG. 1) of the main body 21. Note that the two heat exchangers 22 may be arranged so that the distance between the upper ends is the same as the distance between the lower ends, or the distance between the upper ends is shorter than the distance between the lower ends when viewed from the front side of the main body 21.

[0017] The auxiliary cooling device 3 cools the heat exchanger 22. The auxiliary cooling device 3 includes two water spray mats 31 and a water spraying device 4.

[0018] The two water spray mats 31 are arranged outside the main body 21 at positions respectively facing the right side wall and the left side wall of the main body 21. Each water spray mat 31 is formed in a plate shape from a breathable material. Each water spray mat 31 includes a first main surface 31A and a second main surface 31B located on the opposite side of the first main surface 31A. Each water spray mat 31 is arranged such that the first and second main surfaces 31A and 31B are substantially parallel to the vertical direction and cover the opening 211 of the main body 21. Each water spray mat 31 is arranged such that the first main surface 31A faces the heat exchanger 22. A filter (not shown) is arranged on the second main surface 31B side of each water spray mat 31. The filter prevents foreign matter from adhering to the water spray mat 31 and making it difficult for air to pass through the water spray mat 31.

[0019] The water-dispensing mat 31 may be made of a material with low resistance when air passes through it and capable of smoothly performing heat exchange with water. Examples of the water-dispensing mat 31 that is easy for air to pass through include non-woven fibrous bodies. The water-dispensing mat 31 may be made of a material having water absorption and high durability. The thickness of the water-dispensing mat 31 is, for example, about several centimeters. From the perspective of effective utilization of resources, it is preferable to use the water-dispensing mat 31 obtained by recycling waste plastic and reprocessing it into a fibrous form. From the perspective of ease of installation of the water-dispensing mat 31, the water-dispensing mat 31 is preferably formed of a stretchable material. The water-dispensing mat 31 may be composed of a single mat or may be composed of a plurality of mats arranged in at least one of the vertical and front-rear directions.

[0020] The water-dispensing device 4 cools the heat exchanger 22 by supplying water to the water-dispensing mat 31 arranged at a position facing the heat exchanger 22, taking the latent heat of vaporization from the air passing through the water-dispensing mat 31 wetted with water due to the evaporation of water, and performing heat exchange between the air (hereinafter sometimes referred to as "cooling air") from which the latent heat of vaporization has been taken and the heat exchanger 22. When supplying water to the water-dispensing mat 31, the water-dispensing device 4 detects the position of the lower end of the wetted area (hereinafter sometimes referred to as the "water-wetted area") of the water-dispensing mat 31, and adjusts the amount of water supplied to the water-dispensing mat 31 based on the position of the lower end of the water-wetted area. The water-dispensing device 4 includes a water supply unit 41 and six lower-end detection units 42.

[0021] The water supply unit 41 supplies water to the water-dispensing mat 31 based on the control of a control unit 47 described later. The water supply unit 41 includes two water-dispensing headers 411, a water supply pipe 412, a water supply device 413, six flow rate adjustment valves 414, and four drain pipes 415.

[0022] Of the two watering headers 411, one watering header 411 is disposed above the left watering mat 31, and the remaining watering header 411 is disposed above the right watering mat 31. The watering header 411 supplies water to the watering mat 31 located below the watering header 411. The watering header 411 is formed in a box shape extending from the front end (the right end in FIG. 2) to the rear end (the left end in FIG. 2) of the watering mat 31. A plurality of watering holes (not shown) arranged in the front-rear direction of the watering mat 31 are formed in the bottom wall of the watering header 411. Inside the watering header 411, a partition portion 411B is formed that partitions the internal space of the watering header 411 into a plurality of divided spaces 411A (in this embodiment, three divided spaces 411A).

[0023] The water supply pipe 412 supplies water to the watering header 411. The water supply pipe 412 includes a base pipe portion 412A that extends vertically at the rear side of the main body 21. The lower end of the base pipe portion 412A is connected to the water supply device 413. The water supply device 413 is driven based on the control of the control unit 47. The upper end of the base pipe portion 412A is connected to the center of an intermediate pipe portion 412B that extends horizontally. Horizontal pipe portions 412C that extend in the front-rear direction are connected to the left end and the right end of the intermediate pipe portion 412B above the left and right watering mats 31, respectively. Vertical pipe portions 412D that extend vertically are connected to a plurality of portions arranged in the front-rear direction in the horizontal pipe portion 412C (in this embodiment, three portions). The lower end of each vertical pipe portion 412D is connected to a portion corresponding to each divided space 411A on the upper wall of the watering header 411. That is, the water supply pipe 412 includes six vertical pipe portions 412D. One flow rate adjustment valve 414 is arranged in each of the six vertical pipe portions 412D. The flow rate adjustment valve 414 continuously or intermittently adjusts the flow rate of water flowing from the vertical pipe portion 412D into the watering header 411 based on the control of the control unit 47.

[0024] With the above configuration, the water supplied from the water supply device 413 passes through each vertical pipe section 412D and each divided space 411 of the water sprinkling header 411, and is supplied (dropped) to the area located vertically below each divided space 411 in the water sprinkling mat 31. Also, the amount of water flowing into each divided space 411 of the water sprinkling header 411 is individually controlled by adjusting the opening degree of each flow rate adjustment valve 414. A part constituting one divided space 411 in the water sprinkling header 411, one vertical pipe section 412D supplying water to the divided space 411, and one flow rate adjustment valve 414 arranged in the vertical pipe section 412D constitute one water supply section 40. The water supply section 40 mainly supplies water to the divided area 311 located below the divided space 411 among the plurality of divided areas 311 (in this embodiment, three divided areas 311) obtained by dividing one water sprinkling mat 31 in the width direction. In FIG. 2, the boundary lines of the divided areas 311 are shown by two-dot chain lines, but the adjacent divided areas 311 may get wet due to the water supplied from each water supply section 40 to each divided area 311. The water supply unit 41 includes the same number of water supply sections 40 as the number of divided areas 311 (in this embodiment, since there are two water sprinkling mats 31, a total of six water supply sections 40).

[0025] The drain pipe 415 discharges, below the water sprinkling mat 31, the water that has reached the lower end of the water sprinkling mat 31 without evaporating among the water supplied to the water sprinkling mat 31. The drain pipes 415 are respectively arranged on the front side and the rear side below each water sprinkling mat 31. Note that a configuration may be provided to return the water discharged from the drain pipe 415 to the water supply device 413 and reuse the water returned to the water supply device 413 as the water supplied to the water sprinkling mat 31. Also, the water discharged from the drain pipe 415 may be discarded without being reused as the water supplied to the water sprinkling mat 31.

[0026] Each lower end detection unit 42 detects the position of the lower end of the water-wetted area of each divided area 311 in the water sprinkling mat 31. Each lower end detection unit 42 includes an inner dry bulb temperature detection unit 43 and a wet bulb temperature detection unit 44.

[0027] Each inner dry-bulb temperature detection unit 43 detects the dry-bulb temperature (hereinafter, may be referred to as "inner dry-bulb temperature") between each divided region 311 and the heat exchanger 22. Each inner dry-bulb temperature detection unit 43 may be arranged near each divided region 311. For example, although the distance from each inner dry-bulb temperature detection unit 43 to each divided region 311 is not limited, each inner dry-bulb temperature detection unit 43 is arranged at a position where it is not affected by rainwater or water droplets from sprinkling between each divided region 311 and the heat exchanger 22. Also, even if each inner dry-bulb temperature detection unit 43 is a detection unit that is not affected by rainwater or water droplets from sprinkling, the distance from each inner dry-bulb temperature detection unit 43 to each divided region 311 is not limited. Each inner dry-bulb temperature detection unit 43 may be arranged at a position between each divided region 311 and the heat exchanger 22 and satisfying the following formula (1). Lm×0.9≦L1≦Lm×0.75 … (1) Lm: The distance from the upper end to the lower end of the divided region 311 (the water sprinkling mat 31) L1: The distance from the upper end of the divided region 311 (the water sprinkling mat 31) to the inner dry-bulb temperature detection unit 43

[0028] Each inner dry-bulb temperature detection unit 43 is respectively provided with an inner dry-bulb temperature sensor 431 for detecting the inner dry-bulb temperature. Each inner dry-bulb temperature sensor 431 outputs a signal corresponding to the inner dry-bulb temperature to the control unit 47.

[0029] Each wet-bulb temperature detection unit 44 detects the wet-bulb temperature (hereinafter, may be referred to as "outer wet-bulb temperature") at a position on the opposite side of the heat exchanger 22 with respect to each divided region 311. Each wet-bulb temperature detection unit 44 may be arranged in the vicinity of each divided region 311. For example, although the distance from each wet-bulb temperature detection unit 44 to each divided region 311 is not limited, each wet-bulb temperature detection unit 44 is arranged in the vicinity of each divided region 311 so as not to be affected by raindrops or water droplets from watering. Also, even if each wet-bulb temperature detection unit 44 is a detection unit that is not affected by raindrops or water droplets from watering, each wet-bulb temperature detection unit 44 may be arranged in the vicinity of each divided region 311, and the distance from each wet-bulb temperature detection unit 44 to each divided region 311 is not limited. Each wet-bulb temperature detection unit 44 may be arranged at a position on the opposite side of the heat exchanger 22 with respect to each divided region 311 and at a position that satisfies the following formula (2). In the present embodiment, each wet-bulb temperature detection unit 44 is arranged at a position such that the distance L2 from the upper end of the divided region 311 to the wet-bulb temperature detection unit 44 is approximately the same as the distance L1 from the upper end of the divided region 311 to the inner dry-bulb temperature detection unit 43. Note that when the wet-bulb temperature on the upper end side of the divided region 311 and the wet-bulb temperature on the lower end side of the divided region 311 can be regarded as the same or substantially the same, each wet-bulb temperature detection unit 44 may be arranged above or below each inner dry-bulb temperature detection unit 43. Lm×0.9≦L2≦Lm×0.75 … (2) L2: Distance from the upper end of the divided region 311 (watering mat 31) to the wet-bulb temperature detection unit 44

[0030] Each wet-bulb temperature detection unit 44 includes an outer dry-bulb temperature sensor 441 and a humidity sensor 442, respectively.

[0031] Each outside dry-bulb temperature sensor 441 detects the dry-bulb temperature (hereinafter sometimes referred to as "outside dry-bulb temperature") on the outside of each divided region 311 (the side opposite to the heat exchanger 22 with respect to the water spray mat 31). Each outside dry-bulb temperature sensor 441 may be arranged between the humidity sensor 442 and the divided region 311. For example, each outside dry-bulb temperature sensor 441 may be arranged at a position where the distance to the humidity sensor 442 is 10 mm or less. Although FIG. 1 shows an example where each outside dry-bulb temperature sensor 441 is arranged between the humidity sensor 442 and the divided region 311, each outside dry-bulb temperature sensor 441 only needs to be arranged in the vicinity of the humidity sensor 442. For example, each outside dry-bulb temperature sensor 441 may be arranged in front of or behind the humidity sensor 442, or each outside dry-bulb temperature sensor 441 may be arranged on the side opposite to the divided region 311 with respect to the humidity sensor 442 as shown in FIG. 1. Each outside dry-bulb temperature sensor 441 outputs a signal corresponding to the outside dry-bulb temperature to the control unit 47.

[0032] Each humidity sensor 442 detects the humidity (hereinafter sometimes referred to as "outside humidity") on the outside of each divided region 311. Each humidity sensor 442 outputs a signal corresponding to the outside humidity to the control unit 47. Based on the outside dry-bulb temperature and the outside humidity, the outside wet-bulb temperature at the position on the side opposite to the heat exchanger 22 with respect to each divided region 311 is calculated.

[0033] In the lower-end detection unit 42 having the above configuration, based on the temperature difference between the inside dry-bulb temperature and the outside wet-bulb temperature, the lower end of the wetted region of the water spray mat 31 is detected. Here, the reason why the lower end of the water-wetted region of the water spray mat 31 (divided region 311) can be detected based on the temperature difference between the inside dry-bulb temperature and the outside wet-bulb temperature will be explained.

[0034] When the watering control described later is performed using the watering device 4, the fan 23 is driven. When the fan 23 is driven, as indicated by the arrow A in FIG. 1, an air flow is generated from the outside to the inside of the watering mat 31 (between the watering mat 31 and the heat exchanger 22). The air that has passed through the watering mat 31 (hereinafter sometimes referred to as "passing air") is guided by the fan 23 in a direction approaching the heat exchanger 22. The heat exchanger 22 is cooled by heat exchange with the passing air. The passing air that has undergone heat exchange with the heat exchanger 22 passes through the heat exchanger 22 and is discharged above the main body 21.

[0035] When the watering mat 31 is wet, with the evaporation of water from the watering mat 31, the latent heat of vaporization is taken from the passing air. The heat exchanger 22 is cooled by the passing air from which the latent heat of vaporization has been taken, that is, the cooling air. Also, with the supply of water from above the watering mat 31 to the watering mat 31, as the water-wetted area of the watering mat 31 becomes larger downward, the latent heat of vaporization is taken from the passing air at a lower position with the evaporation of water, and the inner dry-bulb temperature detected by the inner dry-bulb temperature detection unit 43 becomes lower. As a result, as long as the outer wet-bulb temperature does not change significantly due to a sudden change in the weather or the like, as the water-wetted area of the watering mat 31 becomes larger downward, that is, as the lower end of the water-wetted area moves downward, the temperature difference between the inner dry-bulb temperature and the outer wet-bulb temperature becomes smaller. The temperature difference between the inner dry-bulb temperature and the outer wet-bulb temperature becomes smaller as the lower end of the water-wetted area moves downward when the lower end of the water-wetted area exists above the inner dry-bulb temperature detection unit 43. However, when the lower end of the water-wetted area exists below the inner dry-bulb temperature detection unit 43, the temperature difference between the inner dry-bulb temperature and the outer wet-bulb temperature hardly changes even when the lower end of the water-wetted area moves downward. In the present embodiment, as described above, based on the relationship that the smaller the temperature difference between the inner dry-bulb temperature and the outer wet-bulb temperature, the closer the position of the lower end of the water-wetted area of the watering mat 31 is to the inner dry-bulb temperature detection unit 43, the position of the lower end of the water-wetted area is detected. Therefore, for example, compared with a configuration that detects the position of the lower end of the water-wetted area using image processing, the position of the lower end of the water-wetted area can be easily detected with simple processing.

[0036] As shown in FIG. 3, the watering device 4 further includes an operation unit 45, a storage unit 46, and a control unit 47.

[0037] The operation unit 45 is configured to be able to transmit and receive various signals to and from the control unit 47. The operation unit 45 is operated by the user of the auxiliary cooling device 3. The operation unit 45 outputs a signal corresponding to the operation to the control unit 47. For example, when the operation unit 45 receives an operation to start the watering control, it outputs a signal to start the watering control to the control unit 47. When the operation unit 45 receives an operation to end the watering control, it outputs a signal to end the watering control to the control unit 47.

[0038] The storage unit 46 is configured to be able to transmit and receive various data to and from the control unit 47. The storage unit 46 stores various data for controlling the watering device 4. For example, the storage unit 46 stores calculation information indicating the relationship between the outside dry-bulb temperature, the outside humidity, and the outside wet-bulb temperature. The storage unit 46 further stores a threshold value used for determining whether to perform the watering control and a target value used for adjusting the water supply amount to the watering mat 31.

[0039] The control unit 47 adjusts the amount of water supplied to the watering mat 31 based on the position of the lower end of the water-wetted area of the watering mat 31. For this reason, the amount of water discharged below the watering mat 31 without evaporation can be reduced. In the present embodiment, the control unit 47 adjusts the amount of water supplied by each water supply unit 40 based on the temperature difference between the inside dry-bulb temperature and the outside wet-bulb temperature at the position corresponding to each divided area 311 of the plurality of divided areas 311 of the watering mat 31. When the watering mat 31 is large, due to the difference in the air suction speed in each part of the heat exchanger 22 or the distortion of the filter of the watering mat 31, etc., the entire watering mat 31, that is, the plurality of divided areas 311 may not be wetted uniformly. By adopting a configuration in which the water supply amount is adjusted for each divided area 311 as in the present embodiment, even when the watering mat 31 is large, an amount of water corresponding to the wetting condition can be supplied to each divided area 311. Therefore, the plurality of divided areas 311 can be wetted uniformly, and the heat exchanger 22 can be cooled uniformly.

[0040] The control unit 47 is configured to be able to transmit and receive various signals to and from the water supply device 413, the six flow rate adjustment valves 414, the six inner dry bulb temperature detection units 43, or the six wet bulb temperature detection units 44. In FIG. 3, one flow rate adjustment valve 414, one inner dry bulb temperature detection unit 43, and one wet bulb temperature detection unit 44 are shown respectively.

[0041] <Operation of the watering device> Next, the operation of the watering device 4 will be described. FIGS. 4 and 5 are flowcharts of the watering control performed by the watering device 4. In the following, among the six divided areas 311 included in the two watering mats 31, the watering control for one divided area 311 will be described, but the same watering control as that described below is also performed for the remaining five divided areas 311.

[0042] As shown in FIG. 4, the control unit 47 determines whether to start the watering control based on the signal from the operation unit 45 (step S1). When the control unit 47 determines not to start the watering control (step S1: NO), it adjusts the opening degree of the flow rate adjustment valve 414 to 0% (step S2). By the process of step S2, water is not supplied from the water supply unit 40 to the divided area 311. After performing the process of step S2, the control unit 47 performs the process of step S1.

[0043] On the other hand, when the control unit 47 determines to start the watering control (step S1: YES), it determines whether the outside humidity is less than the threshold value based on the signal from the humidity sensor 442 (step S3). As the threshold value, 85% which is the humidity when it is raining can be exemplified, but any value other than 85% may be used as long as it is the humidity indicating that it is raining. Note that the unit control unit may start driving the fan 23 when it determines to start the watering control in step S1, or may keep the fan 23 driven at all times regardless of whether it determines to start the watering control.

[0044] When the control unit 47 determines that the outside humidity is not less than the threshold value (step S3: NO), it adjusts the opening degree of the flow rate adjustment valve 414 to 0% (step S2). The case where it is determined that the outside humidity is not less than the threshold value is when it is raining. When it is raining, even if water is not supplied from the water supply unit 40 to the divided area 311, since the divided area 311 is wet with rain, water evaporates from the divided area 311. The heat exchanger 22 is cooled by the cooling air generated along with the evaporation of this water. When the opening degree of the flow rate adjustment valve 414 has already been adjusted to 0% at the time when it is determined that the outside humidity is not less than the threshold value (step S3: NO), the control unit 47 does not perform the process of step S2, performs the process of step S1, and in the process of step S1, determines to start the watering control.

[0045] On the other hand, when the control unit 47 determines that the outside humidity is less than the threshold value (step S3: YES), it calculates the outside wet bulb temperature based on the outside dry bulb temperature based on the signal from the outside dry bulb temperature sensor 441, the outside humidity based on the signal from the humidity sensor 442, and the calculation information stored in the storage unit 46 (step S4). The case where it is determined that the outside humidity is less than the threshold value is when it is not raining, for example, when it is sunny. Next, the control unit 47 calculates the temperature difference between the outside wet bulb temperature and the inside dry bulb temperature based on the signal from the inside dry bulb temperature sensor 431 (step S5). Since the inside dry bulb temperature does not become less than or equal to the outside wet bulb temperature, the control unit 47 calculates the value obtained by subtracting the outside wet bulb temperature from the inside dry bulb temperature as the temperature difference.

[0046] Next, the control unit 47 determines whether the temperature difference is less than the target value + 2K (step S6). The target value of the temperature difference is preferably set to the temperature difference when the position of the lower end of the water-wetted area is at the same height as the inner dry-bulb temperature detection unit 43 or slightly below the inner dry-bulb temperature detection unit 43 (the distance from the inner dry-bulb temperature detection unit 43 to the lower end of the water-wetted area is within 10 mm). By setting the target value to such a value, as will be described later, when the control unit 47 determines that the temperature difference has become less than or equal to the target value, the position of the lower end of the water-wetted area can be made substantially the same as the position of the inner dry-bulb temperature detection unit 43 or slightly below the inner dry-bulb temperature detection unit 43. Therefore, when the control unit 47 determines that the temperature difference has become less than or equal to the target value, by reducing the water supply amount and suppressing the position of the lower end of the water-wetted area from moving further downward, the amount of water drained downward without evaporating from the divided area 311 can be made 0 or less than a predetermined amount. As the target value, for example, a value of 2K or more and 3K or less can be exemplified.

[0047] When the control unit 47 determines that the temperature difference is not less than the target value + 2K (step S6: NO), it increases the opening degree of the flow rate adjustment valve 414 by the first adjustment amount and supplies water to the divided area 311 (step S7). The first adjustment amount is a sufficiently large amount compared to the second adjustment amount described later. As the first adjustment amount, a value of 70% or more and 100% or less can be exemplified. After performing the process of step S7, the control unit 47 performs the process of step S6 after a predetermined time has elapsed.

[0048] When the opening degree of the flow rate adjustment valve 414 increases due to the process of step S7, the water supply amount per unit time to the divided region 311 increases. When the water supply amount per unit time is larger than the evaporation amount of water from the divided region 311 per unit time, the lower end of the water-wetted region moves downward, and the range where water evaporates in the divided region 311 becomes larger. When the range where water evaporates becomes larger, the range of contact with the cooling air in the heat exchanger 22 becomes larger. Also, since the cooling air is generated at a lower position, the inner dry bulb temperature becomes lower, and the temperature difference becomes smaller when the process of step S7 is performed, as long as the outer wet bulb temperature does not change significantly due to sudden changes in the weather or the like.

[0049] On the other hand, when the control unit 47 determines that the temperature difference is less than the target value + 2K (step S6: YES), as shown in FIG. 5, it determines whether the temperature difference is less than the target value + 1K (step S8). The determination that the temperature difference is less than the target value + 2K is made when the divided region 311 is somewhat wet. When the control unit 47 determines that the temperature difference is not less than the target value + 1K (step S8: NO), it increases the opening degree of the flow rate adjustment valve 414 by a second adjustment amount (step S9). The determination that the temperature difference is not less than the target value + 1K is made when a part of the divided region 311 is wet, but the amount of water sprayed is insufficient to make the temperature difference the target value. The second adjustment amount is a larger amount compared to the third adjustment amount described later. As the second adjustment amount, a value of 50% or more and less than 70% can be exemplified. After performing the process of step S9, the control unit 47 performs the process of step S8 after a predetermined time has elapsed.

[0050] When the process of step S9 is performed, compared with the case where the opening degree of the flow rate adjustment valve 414 is further increased by the first adjustment amount, the amount of water supplied to the divided region 311 per unit time decreases, and the speed at which the water-wetted region of the divided region 311 increases becomes slower. However, since the supply of water to the divided region 311 continues, as long as the water supply amount per unit time remains larger than the evaporation amount of water from the divided region 311 per unit time, the water-wetted region continues to increase downward. As a result, the range of contact with the cooling air in the heat exchanger 22 becomes even larger. Also, since the cooling air is generated at a lower position, the inner dry bulb temperature becomes lower, and the temperature difference becomes smaller when the process of step S9 is performed, unless the outer wet bulb temperature changes significantly due to a sudden change in the weather or the like. Further, when the process of step S9 is performed, compared with the case where the opening degree of the flow rate adjustment valve 414 is further increased by the first adjustment amount, the rate at which the temperature difference per unit time decreases becomes smaller, so that it is possible to suppress the temperature difference from dropping significantly below the target value. As a result, it is possible to suppress the lower end of the water-wetted region from unintentionally moving too far downward and the water contained in the divided region 311 from being drained downward without evaporation.

[0051] On the other hand, when the control unit 47 determines that the temperature difference is less than the target value + 1K (step S8: YES), it increases the opening degree of the flow rate adjustment valve 414 by the third adjustment amount (step S10). The determination that the temperature difference is less than the target value + 1K is made when the temperature difference is approaching the target value. The third adjustment amount is approximately the same amount as the fourth adjustment amount described later. As the third adjustment amount, a value of 30% or more and less than 50% can be exemplified. When the process of step S10 is performed, compared with the case where the opening degree of the flow rate adjustment valve 414 is further increased by the first adjustment amount or the second adjustment amount, the speed at which the water-wetted area increases becomes slower. However, as long as the water supply amount per unit time continues to be more than the evaporation amount of water from the divided area 311 per unit time, the water-wetted area continues to increase downward. As a result, the range in contact with the cooling air in the heat exchanger 22 becomes even larger. Also, since the cooling air is generated at a lower position, the temperature difference becomes smaller when the process of step S10 is performed unless the outside wet-bulb temperature changes significantly due to a sudden change in the weather or the like. Further, due to the process of step S10, compared with the case where the opening degree of the flow rate adjustment valve 414 is further increased by the first adjustment amount or the second adjustment amount, the rate at which the temperature difference per unit time decreases becomes smaller, so that it is possible to suppress the temperature difference from decreasing significantly below the target value. As a result, it is possible to suppress the lower end of the water-wetted area from unintentionally moving downward too much and the water contained in the divided area 311 from being drained downward without evaporation.

[0052] Next, the control unit 47 determines whether the temperature difference is less than or equal to the target value (step S11). When the control unit 47 determines that the temperature difference is not less than or equal to the target value (step S11: NO), after a predetermined time has elapsed, the process of step S10 is performed. The temperature difference is determined not to be less than or equal to the target value when the temperature difference and the target value are approximately the same. On the other hand, when the control unit 47 determines that the temperature difference is less than or equal to the target value (step S11: YES), the opening degree of the flow rate adjustment valve 414 is decreased by the fourth adjustment amount (step S12). The temperature difference is determined to be less than or equal to the target value because water is supplied to the difficult-to-dry (difficult for water to evaporate) divided region 311, causing the lower end of the water-wetted region to drop to a position near the inner dry-bulb temperature detection unit 43, and there is a possibility that the amount of water (drainage amount) discharged downward from the divided region 311 without evaporating increases. The divided region 311 becomes more difficult to dry (more difficult for water to evaporate), for example, when the outside humidity is high. As the fourth adjustment amount, a value of 0% or more and less than 30% can be exemplified. After performing the process of step S12, the control unit 47 performs the process of step S11 after a predetermined time has elapsed. Note that when the control unit 47 acquires a signal indicating the end of the watering control from the operation unit 45 during the above-described watering control, the watering control is terminated.

[0053] As described above, the control unit 47 repeats the process of reducing the opening degree of the flow rate adjustment valve 414 by the fourth adjustment amount (step S12) in step S11 until it is determined that the temperature difference is not less than the target value. When the water supply amount per unit time to the divided region 311 is reduced by the process of step S12, the speed at which the water-wetted region increases is slower than when increasing the water supply amount to the divided region 311. As long as the water-wetted region continues to increase downward, the range in contact with the cooling air in the heat exchanger 22 becomes larger while the temperature difference becomes smaller. However, if the water supply amount per unit time to the divided region 311 continues to be reduced and the water supply amount becomes less than the evaporation amount of water from the divided region 311 per unit time, drying starts from the lower side of the divided region 311 and the lower end of the water-wetted region moves upward. When the lower end of the water-wetted region moves upward, the range in contact with the cooling air in the heat exchanger 22 becomes smaller while the inner dry-bulb temperature detected by the inner dry-bulb temperature detection unit 43 becomes higher and the temperature difference becomes larger. Then, in step S11, when the control unit 47 determines that the temperature difference exceeds the target value, that is, the temperature difference is not less than the target value, it performs the process of step S10 to increase the water supply amount per unit time to the divided region 311. By the process of this step S10, this time, the lower end of the water-wetted region moves downward, the range in contact with the cooling air in the heat exchanger 22 becomes larger while the temperature difference becomes smaller. After that, the control unit 47 repeats the process of step S10 until the temperature difference becomes not less than the target value, and when the temperature difference becomes not less than the target value, this time, it repeats the process of step S12 until the temperature difference exceeds the target value.

[0054] By performing the above processes, the water sprinkling device 4 adjusts the water supply amount to the divided region 311 so that the temperature difference becomes the target value, that is, the lower end of the water-wetted region is positioned near the inner dry-bulb temperature detection unit 43. For this reason, the amount of water discharged downward without evaporating in the divided region 311 can be reduced.

[0055] When the outside humidity is less than the threshold value and it is estimated that it is not raining, the watering device 4 performs watering control based on the position of the lower end of the water-wetted area, and when the outside humidity is equal to or greater than the threshold value and it is estimated that it is raining, the watering control is not performed. In this way, by performing watering control when the watering mat 31 is not wet and not performing watering control when the watering mat 31 is wet by rain, the processing load of the watering device 4 can be reduced while the heat exchanger 22 can be cooled.

[0056] The inner dry bulb temperature detection unit 43 is arranged at a position that satisfies "L1 ≤ Lm × 0.75" in the above formula (1). Therefore, by adjusting the water supply amount by the control unit 47, it is possible to always wet 75% or more of the upper region of the divided region 311 with water, and it is possible to increase the range of contact with the cooling air in the heat exchanger 22. Therefore, the cooling efficiency of the heat exchanger 22 can be increased. Further, the inner dry bulb temperature detection unit 43 is arranged at a position that satisfies "Lm × 0.9 ≤ L1" in the above formula (1). Therefore, by adjusting the water supply amount by the control unit 47, the distance from the upper end of the divided region 311 to the lower end of the water-wetted area can be made a distance of 90% or less of the height of the divided region 311, and the possibility of water being drained from the divided region 311 can be reduced.

[0057] In addition, when an electromagnetic valve that can only make an alternative selection of opening or closing the flow path is provided in each water supply unit 40 of the watering device 4, it is necessary to adjust the water supply amount with a needle valve in consideration of the influence of water pressure at the initial stage of construction of the watering device 4, and there is a possibility that the workability will deteriorate. Further, when the water pressure fluctuates, only an amount of water corresponding to the water pressure after the fluctuation can be supplied, so there is a possibility that each divided region 311 cannot be appropriately wetted. Each water supply unit 40 of the present embodiment includes a flow rate adjustment valve 414 that can continuously or intermittently adjust the flow rate of water. Therefore, it is not necessary to adjust the water supply amount at the initial stage of construction of the watering device 4. Further, when the water pressure fluctuates, the control unit 47 adjusts the opening degree of the flow rate adjustment valve 414 according to the fluctuation, so that each divided region 311 can be appropriately and uniformly wetted.

[0058] [Modification Example of Embodiment] Needless to say, the present disclosure is not limited to what is shown in the embodiments described so far, and various modifications can be made without departing from the spirit thereof. Further, the above embodiments and the modification examples shown below can be combined in any manner as long as they function properly.

[0059] For example, as a method of controlling the water supply amount to the divided region 311 so that the temperature difference between the inner dry-bulb temperature and the outer wet-bulb temperature becomes the target value, the method is not limited to the methods shown in FIGS. 4 and 5, and the method shown in FIG. 6 may be applied. In the method shown in FIG. 6, when the watering control is started at time T0, the opening degree of the flow rate adjustment valve 414 is continuously increased until the temperature difference becomes equal to or less than the target value (up to time T1). Then, when the temperature difference becomes equal to or less than the target value, the process of continuously decreasing the opening degree of the flow rate adjustment valve 414 until the temperature difference becomes equal to or greater than the target value + a predetermined value (between time T1 and T2, between time T3 and T4, between time T5 and T6, between time T7 and T8), and when the temperature difference becomes equal to or greater than the target value + a predetermined value, the process of continuously increasing the opening degree of the flow rate adjustment valve 414 until the temperature difference becomes equal to or less than the target value (between time T2 and T3, between time T4 and T5, between time T6 and T7) are repeated.

[0060] As the lower end detection unit 42, a configuration may be applied in which the position of the lower end of the water-wetted area is detected by performing image processing on the image captured by the imaging unit. Further, as the lower end detection unit 42, a configuration for detecting the drainage amount from the drainage pipe 415 (for example, a flow rate sensor) is applied, and when the control unit 47 detects the drainage from the drainage pipe 415 after starting the water supply to the watering mat 31, that is, when it is detected that the position of the lower end of the water-wetted area has reached the lower end of the watering mat 31, the processing after step S4 shown in FIG. 4 may be performed.

[0061] As the wet-bulb temperature detection unit 44, a wet-bulb temperature sensor for detecting the wet-bulb temperature may be applied instead of the outer dry-bulb temperature sensor 441 and the humidity sensor 442.

[0062] Regardless of the value of the outside humidity, that is, regardless of whether it is raining or not, the watering device 4 may perform watering control based on the position of the lower end of the water-wetted area.

[0063] Although a configuration in which the water supply part 40 and the lower end detection part 42 are arranged at positions corresponding to each of the divided areas 311 is illustrated, one water supply part 40 and one lower end detection part 42 may be arranged on each watering mat 31.

[0064] Although a configuration in which a flow rate adjustment valve 414 capable of continuously or intermittently adjusting the flow rate of water is provided in each water supply part 40 is illustrated, a solenoid valve that can only make an alternative selection of opening or closing the flow path may be provided instead of the flow rate adjustment valve 414.

Industrial Applicability

[0065] The present disclosure can be applied to a watering device and a watering method.

Explanation of Signs

[0066] 1 Refrigerant cooling device 2 Cooling unit 3 Auxiliary cooling device 4 Watering device 21 Main body 22 Heat exchanger 23 Fan 31 Watering mat 31A First main surface 31B Second main surface 40 Water supply part 41 Water supply unit 42 Lower end detection part 43 Inside dry bulb temperature detection part 44 Wet bulb temperature detection part 45 Operation part 46 Storage part 47 Control part 211 Opening 311 Divided area 411 Watering header 411A Divided space 411B Partition part 412 Water supply pipe 412A Base Pipe Section 412B Intermediate Pipe Section 412C Horizontal Pipe Section 412D Vertical Pipe Section 413 Water Supply Device 414 Flow Control Valve 415 Drain Pipe 431 Inner Dry-Bulb Temperature Sensor 441 Outer Dry-Bulb Temperature Sensor 442 Humidity Sensor

Claims

1. A watering device that cools a heat exchanger with air whose latent heat of vaporization is taken away as water evaporates from a watering mat wetted with water, comprising: a dry bulb temperature detection unit that detects the dry bulb temperature and a wet bulb temperature detection unit that detects the wet bulb temperature; a lower end detection unit that detects the position of the lower end of the wetted area of the watering mat based on the dry bulb temperature and the wet bulb temperature; a control unit that adjusts to reduce the amount of water supplied to the watering mat based on the position of the lower end of the wetted area, wherein the dry bulb temperature detection unit is an inner dry bulb temperature detection unit disposed between the watering mat and the heat exchanger, and the wet bulb temperature detection unit is disposed at a position on the opposite side of the heat exchanger with respect to the watering mat, wherein the lower end detection unit detects the position of the lower end of the wetted area based on the relationship that the lower the temperature difference between the dry bulb temperature detected by the inner dry bulb temperature detection unit and the wet bulb temperature detected by the wet bulb temperature detection unit, the closer the position of the lower end of the wetted area is to the inner dry bulb temperature detection unit; A watering device.

2. The wet bulb temperature detection unit includes a humidity sensor that detects humidity and an outer dry bulb temperature sensor that detects the dry bulb temperature, wherein the wet bulb temperature is calculated based on the humidity detected by the humidity sensor and the dry bulb temperature detected by the outer dry bulb temperature sensor. The watering device according to claim 1.

3. When the humidity detected by the humidity sensor is less than a threshold value, the control unit adjusts the amount of water supplied to the watering mat based on the position of the lower end of the wetted area, while when the humidity detected by the humidity sensor is greater than or equal to the threshold value, the control unit does not supply water to the watering mat. The watering device according to claim 2.

4. The inner dry bulb temperature detection unit is disposed at a position that satisfies the following formula (1) between the watering mat and the heat exchanger: Lm × 0.9 ≤ L1 ≤ Lm × 0.75... (1) Lm: the distance from the upper end to the lower end of the watering mat L1: the distance from the upper end of the watering mat to the inner dry bulb temperature detection unit The watering device according to any one of claims 1 to 3.

5. The watering device further includes a plurality of water supply units that supply water to a plurality of divided areas obtained by horizontally dividing the watering mat, wherein the inner dry bulb temperature detection unit and the wet bulb temperature detection unit are disposed at positions corresponding to the plurality of divided areas respectively. The control unit adjusts the amount of water supplied by the water supply unit based on the position of the lower end of the wetted area for each of the plurality of divided areas. The sprinkler device according to any one of claims 1 to 3.

6. The plurality of water supply units each include a flow rate adjustment valve for adjusting the flow rate of water. The control unit adjusts the amount of water supplied by the water supply unit by controlling the flow rate adjustment valve for each of the plurality of divided areas. The sprinkler device according to claim 5.

7. A watering method performed by a watering device that cools a heat exchanger with air from which latent heat of vaporization has been taken away due to evaporation of water from a watered watering mat, The watering device includes an inner dry-bulb temperature detection unit disposed between the watering mat and the heat exchanger, a wet-bulb temperature detection unit disposed at a position on the opposite side of the heat exchanger with respect to the watering mat, a lower-end detection unit, and a control unit. The inner dry-bulb temperature detection unit detects the dry-bulb temperature. The wet-bulb temperature detection unit detects the wet-bulb temperature. The lower-end detection unit detects the position of the lower end of the wetted area of the watering mat based on the relationship that the position of the lower end of the wetted area becomes closer to the inner dry-bulb temperature detection unit as the temperature difference between the dry-bulb temperature detected by the inner dry-bulb temperature detection unit and the wet-bulb temperature detected by the wet-bulb temperature detection unit becomes smaller. The control unit adjusts to reduce the amount of water supplied to the watering mat based on the position of the lower end of the wetted area. Watering method.

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