air conditioner

Abstract

To provide an air conditioner which efficiently controls driving of a pump for a water tank.SOLUTION: An air conditioner includes: a cooling unit; a water supply part which supplies water to the cooling unit; a drain pan which stores water dropped from the cooling unit and is connected to the water supply part through a water supply passage; a water tank connected to the drain pan; a water supply pump which supplies water from the drain pan to the water supply part; a pump for the tank which supplies water from the water tank to the drain pan; a flow sensor which is disposed at the water supply passage and detects a flow rate of water flowing from the drain pan to the water supply part; a water level sensor disposed in a water storage space of the drain pan; and a control unit which controls driving of the water supply pump and the pump for the tank. The control unit acquires an output signal output from the water level sensor and the flow sensor and changes a driving state of the pump for the tank based on the acquired output signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an air conditioner. [Background technology]

[0002] Evaporative cooling air conditioners are known that draw in indoor air, use the heat of vaporization of water to lower the ambient temperature, and then blow the cooled air out into the room (see, for example, Patent Document 1). In the air conditioner of Patent Document 1, the air flowing through the second flow path passes through multiple tubes in the sensible heat exchanger, and the air flowing through the first flow path passes around the multiple tubes. As a result, heat is exchanged between the air flowing through the second flow path and the air flowing through the first flow path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-092338 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the air conditioner of Patent Document 1, from the viewpoint of supplying water from the water tank to the drain pan, no consideration is given to efficiently controlling the drive of the water tank pump.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide an air conditioner that can efficiently control the drive of a water tank pump. [Means for solving the problem]

[0006] An air conditioner according to one aspect of the present disclosure comprises a cooling unit, a water supply section that supplies water to the cooling unit, a drain pan that stores water dripping from the cooling unit and is connected to the water supply section via a supply water channel, a water tank connected to the drain pan, a water supply pump that supplies water from the drain pan to the water supply section, a tank pump that supplies water from the water tank to the drain pan, a flow rate sensor that is disposed in the supply water channel and detects the flow rate of water flowing from the drain pan to the water supply section, a water level sensor that is disposed in the water storage space of the drain pan, and a control section that controls the operation of the water supply pump and the tank pump, wherein the control section acquires output signals output from the water level sensor and the flow rate sensor, and changes the operation state of the tank pump based on the acquired output signals. [Effects of the Invention]

[0007] It is possible to provide an air conditioner that efficiently controls the drive of a water tank pump. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional side view showing an example of the configuration of an air conditioner according to a first embodiment. [Figure 2] FIG. 2 is a perspective view showing the front exterior of the air conditioner. [Figure 3] FIG. 2 is a perspective view showing the rear exterior of the air conditioner. [Figure 4] FIG. 2 is a perspective view showing the underside of the exterior of the air conditioner. [Figure 5] FIG. 2 is a block diagram showing each functional unit of the air conditioner. [Figure 6] 10 is a flowchart showing a processing procedure performed by a control unit. [Figure 7] 10 is a flowchart showing a processing procedure performed by a control unit. [Figure 8] 10 is a flowchart showing a processing procedure performed by a control unit according to the second embodiment. [Figure 9] 10 is a flowchart showing a processing procedure performed by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] An air conditioner 1 and the like according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the following examples, and includes all modifications equivalent to and within the scope of the claims.

[0010] (Embodiment 1) Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a schematic side cross-sectional view showing an example of the configuration of an air conditioner 1 according to embodiment 1. FIG. 2 is a perspective view showing the front of the exterior of the air conditioner 1. FIG. 3 is a perspective view showing the rear of the exterior of the air conditioner 1. FIG. 4 is a perspective view showing the underside of the exterior of the air conditioner 1. FIG. 1 is a schematic view of a cross section of the air conditioner 1 from the front. In FIG. 1, the installed state of the air conditioner 1 is the normal usage state of the air conditioner 1, and up, down, left, and right are shown. In FIGS. 2, 3, and 4, the installed state of the air conditioner 1 is the normal usage state of the air conditioner 1, and up, down, front, back, left, and right are shown. In this embodiment, the vertical direction indicates the up-down direction. The first horizontal direction indicates the left-right direction. The second horizontal direction indicates the front-back direction.

[0011] The air conditioner 1 is mounted on vehicles such as commercial vehicles such as forklifts and trucks, tow trucks, aerial work platforms, mini excavators, golf carts, etc. When the air conditioner 1 is mounted on a mobile object such as a forklift, the power to the main body of the air conditioner 1 may be turned on and off in conjunction with the on and off of the key switch for the forklift's engine. In other words, the power to the air conditioner 1 may be turned on by turning on the forklift's engine, and the power to the air conditioner 1 may be turned off by turning off the forklift's engine.

[0012] The housing 10 is a rectangular box made of resin or metal and includes a main body 11 and a door 12 that can be opened and closed relative to the main body 11. The box-shaped housing 10 has a top surface, a bottom surface, and side walls. The side walls include a first side wall 111, a second side wall 112, a third side wall 113, and a fourth side wall 114. In this embodiment, the first side wall 111 corresponds to the rear side wall. The second side wall 112 corresponds to the front side wall. The third side wall 113 corresponds to the right side wall. The fourth side wall 114 corresponds to the left side wall. Therefore, the first side wall 111 and the second side wall 112 face each other. The third side wall 113 and the fourth side wall 114 face each other. The third side wall 113 connects the first side wall 111 and the second side wall 112. The fourth side wall 114 connects the first side wall 111 and the second side wall 112. The first side wall 111 is composed of a main body side first side wall 1111 and a door side first side wall 1112 .

[0013] The door 12 is disposed above the main body 11 and is configured to be able to open and close relative to the main body 11. Specifically, the door-side first side wall 1112 is connected to the main body-side first side wall 1111 by two support parts 115. The support parts 115 may be, for example, hinges.

[0014] A recessed handle portion 118 is formed from the bottom to the bottom surface of each of the third side wall 113 and the fourth side wall 114 of the housing 10. The handle portion 118 is a portion that is gripped when the user carries the air conditioner 1.

[0015] A duct 431 for blowing out supply air is disposed on the top surface of the housing 10. A water tank 8 is disposed next to the second side wall 112 of the housing 10. A tank stand 116 for placing the water tank 8 is located below the second side wall 112 of the housing 10. The water tank 8 is disposed on the tank stand 116, covering the second side wall 112. A drainage channel 781 for draining water from the drain pan 6 is disposed below the tank stand 116. The water tank 8 is detachably attached to the housing 10. The water tank 8 has a handle and can be removed from the housing 10. When refilling the water tank 8 with water, only the water tank 8 can be carried to a water faucet, reducing the workload of the user of the air conditioner 1. A vertically long water level confirmation window 82 is disposed on the side of the water tank 8. The user can visually check the amount of water remaining in the water tank 8 through the water level confirmation window 82.

[0016] The housing 10 is formed with an air supply inlet 42 and an exhaust inlet 52 that draw in air from the space to be air-conditioned. Furthermore, the housing 10 is formed with an air supply outlet 43 and an exhaust outlet 53. The air supply inlet 42 is formed in a third side wall 113 of the housing 10. The exhaust inlet 52 is formed in a door 12 that forms part of the housing 10. The air supply outlet 43 is formed on the top surface of the housing 10 and communicates with a duct 431. The duct 431 is configured to be rotatable in the circumferential direction of the air supply outlet 43, and may have an air direction adjustment plate 432 that adjusts the wind direction of the air supply blown out from the duct 431. The exhaust outlet 53 is formed in a fourth side wall 114 of the housing 10.

[0017] The air conditioner 1 includes a water tank 8 that stores water, and a cooling unit 20 that includes an evaporative filter 2 and a sensible heat exchanger 3 that receive water from the water tank 8. The evaporative filter 2 is housed in an evaporative filter case. The sensible heat exchanger 3 is housed in a heat exchanger case. The evaporative filter 2 uses the heat of vaporization of the water supplied from the water tank 8 to lower the ambient temperature and cool the space to be air-conditioned. The sensible heat exchanger 3 uses the sensible heat and latent heat of the water supplied from the water tank 8 to lower the ambient temperature and cool the space to be air-conditioned. The evaporative filter 2 is located downstream of the sensible heat exchanger 3 in the flow direction of the supply air. In other words, the evaporative filter 2 is located between the sensible heat exchanger 3 and the supply air outlet 43.

[0018] The air passes through sensible heat exchanger 3 and evaporative filter 2 and is cooled in two stages by sensible heat exchanger 3 and evaporative filter 2, and is blown out as supply air into the space to be air-conditioned from supply air outlet 43. Furthermore, as the air passes through sensible heat exchanger 3, it is cooled by water supplied to sensible heat exchanger 3, and then the air that has exchanged sensible heat with the supply air in sensible heat exchanger 3 is blown out as exhaust air from exhaust outlet 53 to the outside of air conditioner 1.

[0019] The supply air inlet 42 and the supply air outlet 43 are connected to each other, and an supply air flow path 4 through which the air to be supplied flows is formed, with the supply air inlet 42 serving as the supply air inlet and the supply air outlet 43 serving as the supply air outlet. That is, the supply air flows from the supply air inlet 42 into the supply air flow path 4 and flows out from the supply air outlet 43. The supply air inlet 42 may be provided with an supply air dust collecting filter that collects dust in the supply air sucked in from the supply air inlet 42.

[0020] The exhaust air inlet 52 and the exhaust air outlet 53 are in communication with each other, and an exhaust flow path 5 through which the exhaust air flows is formed, with the exhaust air inlet 52 as an exhaust inlet and the exhaust air outlet 53 as an exhaust outlet. That is, the exhaust air flows from the exhaust air inlet 52 into the exhaust flow path 5 and flows out from the exhaust air outlet 53. The exhaust air inlet 52 may be provided with an exhaust dust collecting filter that collects dust in the exhaust air sucked in from the exhaust air inlet 52.

[0021] The air conditioner 1 is equipped with fans for transporting supply air and exhaust air. The fans include a supply air fan 41 that transports supply air and an exhaust fan 51 that transports exhaust air. The supply air fan 41 and the exhaust fan 51 may be axial fans such as propeller fans, or sirocco fans. The supply air fan 41 is disposed near the supply air outlet 43, and is located downstream of the cooling unit 20 in the flow direction of the supply air in the supply air flow path 4, and functions as a suction fan.

[0022] Exhaust fan 51 is disposed near exhaust outlet 53, is located downstream of sensible heat exchanger 3 in the exhaust flow direction in exhaust flow path 5, and functions as a suction fan. Intake fan 41 and exhaust fan 51 are not limited to these embodiments, and both may be push fans or suction fans. When intake fan 41 and exhaust fan 51 are configured as push fans, intake fan 41 is disposed near intake inlet 42, and exhaust fan 51 is disposed near exhaust inlet 52.

[0023] The exhaust air transported by exhaust fan 51 is sucked in through exhaust air inlet 52 and flows into exhaust path 32 of sensible heat exchanger 3. Because exhaust air inlet 52 is formed in door 12, the exhaust air sucked in through exhaust air inlet 52 passes through door 12 and then flows into exhaust path 32 of sensible heat exchanger 3.

[0024] Sensible heat exchanger 3 is provided with an intake air path 31 through which intake air flows and an exhaust air path 32 through which exhaust air flows. That is, sensible heat exchanger 3 includes intake air path 31 and exhaust air path 32. As described above, air conditioner 1 is provided with an intake air flow path 4 through which intake air flows and an exhaust air flow path 5 through which exhaust air flows as air circulation paths. Intake air path 31 of sensible heat exchanger 3 constitutes a part of intake air flow path 4, and exhaust air path 32 of sensible heat exchanger 3 constitutes a part of exhaust air flow path 5.

[0025] Intake air path 31 and exhaust air path 32 in sensible heat exchanger 3 are formed by a plurality of hollow resin plates, and these plates are stacked by arranging them in parallel to form sensible heat exchanger 3. By reducing the thickness of the resin plates in sensible heat exchanger 3, heat transfer performance is improved and the weight of sensible heat exchanger 3 is reduced. The hollow structure may be formed from a metal plate.

[0026] The air intake path 31 and the exhaust path 32 are formed by stacking multiple resin plates perpendicular to each other, and sensible heat exchange occurs between the intake air and the exhaust air through these resin plates. The stacking direction of these multiple stacked resin plates is perpendicular to the respective path directions of the air intake path 31 and the exhaust path 32. That is, in this embodiment, the path direction of the air intake path 31 is from right to left, and the path direction of the exhaust path 32 is from top to bottom, whereas the stacking direction is the front-to-back direction, which is perpendicular to both the left-right and up-down directions. Because the air intake path 31 and the exhaust path 32 are perpendicular to each other in this way, a cross flow is formed between the intake air flowing through the air intake path 31 and the exhaust air flowing through the exhaust path 32.

[0027] An inlet and an outlet of air supply path 31 are formed on each of two opposing side surfaces of sensible heat exchanger 3. In the illustration of this embodiment, the inlet of air supply path 31 is located on the right side of sensible heat exchanger 3, and the outlet of air supply path 31 is located on the left side of sensible heat exchanger 3.

[0028] Air supply path 31 is formed by stacking a plurality of spaces that communicate from the inlet of air supply path 31 to the outlet of air supply path 31. An inlet of exhaust path 32 is formed on the upper surface of sensible heat exchanger 3, and an outlet of exhaust path 32 is formed on the lower surface. Exhaust path 32 is formed by stacking a plurality of spaces that communicate from the inlet of exhaust path 32 to the outlet of exhaust path 32.

[0029] A box-shaped drain pan 6 with an opening at the top is disposed below cooling unit 20, i.e., below evaporative filter 2 and sensible heat exchanger 3. Drain pan 6 receives water supplied from heat exchange water supply section 33 and passed through sensible heat exchanger 3. Drain pan 6 also receives water supplied from filter water supply section 21 and passed through evaporative filter 2. Drain pan 6 is disposed downstream of sensible heat exchanger 3 in the exhaust flow direction, with its opening facing the underside of evaporative filter 2 and sensible heat exchanger 3. In other words, the water storage space, which is the internal space of drain pan 6, forms part of exhaust flow path 5.

[0030] The exhaust air is sucked in through exhaust intake port 52 by exhaust fan 51 and passes through exhaust path 32 of sensible heat exchanger 3. It then passes through a water storage space in drain pan 6, which is a box-shaped airflow path with an open top, and is blown out from exhaust outlet 53. As the exhaust air passes through exhaust path 32 of sensible heat exchanger 3, it mixes with water supplied to exhaust path 32 from heat exchange water supply section 33. That is, in exhaust path 32 of sensible heat exchanger 3, the flow direction of the exhaust air and the flow direction of the water are the same, and the exhaust air and water form parallel flows.

[0031] 1 of this embodiment, intake air path 31, through which the intake air flows, is arranged linearly from the right face to the left face of sensible heat exchanger 3. In the flow direction of the intake air, an evaporation filter 2 is arranged downstream of the outlet of intake air path 31. The evaporation filter 2 is arranged in intake air flow path 4 between sensible heat exchanger 3 and intake air outlet 43. A first intermediate intake air path 44 is located between sensible heat exchanger 3 and evaporation filter 2, and first intermediate intake air path 44 constitutes a part of intake air path 4.

[0032] The evaporative filter 2 is arranged with one rectangular surface facing the left surface of the sensible heat exchanger 3, where the outlet of the air intake path 31 is formed. In this way, the evaporative filter 2 functions as a cooling element. The evaporative filter 2 is made of, for example, rayon, polyester, or nonwoven fabric. A filter water supply section 21 having a nozzle is arranged above the evaporative filter 2. The evaporative filter 2 is water-absorbent, and water supplied from the filter water supply section 21 penetrates the entire surface of the evaporative filter 2, promoting the evaporation of the water. The air intake path 4 from the evaporative filter 2 to the air intake outlet 43 extends upward from the evaporative filter 2.

[0033] The supply air flowing out from supply air path 31 of sensible heat exchanger 3 passes through evaporative filter 2 and is blown out into the conditioned space from supply air outlet 43. The supply air flowing out from the outlet of supply air path 31 is cooled in two stages by being primarily cooled by the exhaust air via sensible heat exchanger 3 and then secondarily cooled by evaporative filter 2. Therefore, the temperature of the supply air is further reduced compared to, for example, a direct evaporation method that uses only evaporative filter 2.

[0034] Residual water in the sensible heat exchanger 3 and the evaporative filter 2 unit is received by a drain pan 6 located below the sensible heat exchanger 3 and the evaporative filter 2, and the residual water is collected by being stored in the water storage space of the drain pan 6. The water collected in the drain pan 6 is supplied to the evaporative filter 2 unit and the sensible heat exchanger 3 via a supply water passage 7.

[0035] As shown in FIG. 1 , a drain pan filter 75, a flow rate sensor 77, and a water supply pump 76 are disposed in the water supply passage 7. The water supply passage 7 is configured, for example, with a resin or metal pipe. By driving the water supply pump 76, water stored in the drain pan 6 is supplied by the water supply pump 76 to the filter water supply section 21 disposed above the evaporative filter 2 and the heat exchange water supply section 33 disposed above the sensible heat exchanger 3. Water dripping from a nozzle in the filter water supply section 21 is supplied to the evaporative filter 2. Water dripping from a nozzle in the heat exchange water supply section 33 is supplied to the exhaust path 32 of the sensible heat exchanger 3. In this way, the water supply passage 7, the heat exchange water supply section 33, the filter water supply section 21, and the drain pan 6 form a circulation water passage that circulates water between the drain pan 6 and the evaporative filter 2 and the sensible heat exchanger 3 that constitute the cooling unit 20.

[0036] The water supply passage 7 communicates with a bottom hole 611 formed in the bottom surface 61 of the drain pan 6. The water supply passage 7 includes a first water supply passage 71 extending from bottom to top along the first side wall 111 of the housing 10, a second water supply passage 72 connected to the heat exchange water supply section 33, a connecting water supply passage 73 connecting the first water supply passage 71 and the second water supply passage 72, and a water supply section connecting passage 74 connecting the heat exchange water supply section 33 and the filter water supply section 21. The heat exchange water supply section 33, the filter water supply section 21, the water supply section connecting passage 74, and the second water supply passage 72 are fixed to the door 12. The first water supply passage 71, the second water supply passage 72, and the water supply section connecting passage 74 are formed of pipes made of, for example, resin or metal.

[0037] Heat exchange water supply section 33 is composed of a rectangular hollow pipe made of, for example, resin or metal, and has a plurality of nozzles with holes formed on its underside, which faces sensible heat exchanger 3. Second water supply passage 72 passes above heat exchange water supply section 33 and is connected to a communication port provided on the top of heat exchange water supply section 33. Water flowing from connecting water supply passage 73 into second water supply passage 72 is supplied to heat exchange water supply section 33 through a communication port provided on the top of heat exchange water supply section 33. The water supplied to heat exchange water supply section 33 then drips onto the top surface of sensible heat exchanger 3 from the holes of the plurality of nozzles located on the underside.

[0038] The filter water supply section 21 is configured as a rectangular hollow pipe made of, for example, resin or metal, and has a plurality of nozzles with holes formed on its underside, which faces the evaporation filter 2. A hole is also provided on the right side of the filter water supply section 21, i.e., the side facing the heat exchange water supply section 33. The filter water supply section 21 is located at the same height as the water supply section connecting passage 74 in the vertical direction and is connected to a communication port provided on the side of the filter water supply section 21. Water flowing from the second water supply passage 72 into the water supply section connecting passage 74 is supplied to the filter water supply section 21 through the communication port provided on the side of the filter water supply section 21. The water supplied to the filter water supply section 21 then drips onto the upper surface of the evaporation filter 2 from the holes of the plurality of nozzles located on the underside.

[0039] The supply water channel 7 has a branch 78 that branches into a drain channel 781. The drain channel 781 has the branch 78 as its base end, and a drain outlet with an on-off valve or a cock attached to its tip. The drain channel 781 is made of, for example, a resin pipe. The drain outlet located at the end of the drain channel 781 has an on-off valve that is fully closed during normal use, such as when the air conditioner 1 is operating. During maintenance work, such as maintenance of the air conditioner 1, the on-off valve can be opened to drain water stored in the drain pan 6 out of the air conditioner 1 through the drain outlet.

[0040] The drain pan 6 and the water tank 8 are connected by a replenishment water passage 9. The replenishment water passage 9 is composed of, for example, a resin or metal pipe. A tank pump 91 and a tank flow rate sensor 92 are arranged in the replenishment water passage 9. One end of the replenishment water passage 9 is connected to the bottom of the water tank 8, and the other end of the replenishment water passage 9 is connected to a water supply hole 621 formed in a wall surface 62 of the drain pan 6. The water supply hole 621 is formed to be located higher than the bottom hole 611 to which the supply water passage 7 is connected. A water level sensor 63 is fixed on the bottom surface 61 of the drain pan 6 by a sensor fixing member. The water level sensor 63 is fixed at a position offset from the direction in which water is ejected from the water supply hole 621, i.e., the water outflow direction.

[0041] 5 is a block diagram showing each functional unit in the air conditioner 1. The air conditioner 1 has a board 100 including a control unit 101. A microcomputer including a memory, an MPU, etc. is mounted on the board 100, and the microcomputer functions as the control unit 101 that controls the drive of the water supply pump 76, the tank pump 91, etc. The memory stores a program executed by the control unit 101.

[0042] The substrate 100 may be disposed, for example, on the outer surface of a flow path wall that forms the exhaust flow path 5, and may be thermally connected to the flow path wall, thereby being cooled by the exhaust air flowing through the exhaust flow path 5. The electrical components of the air conditioner 1, namely, the air supply fan 41, the exhaust fan 51, the water level sensor 63, the water supply pump 76, the flow rate sensor 77, the tank pump 91, and the tank flow rate sensor 92, are communicatively connected to a control unit 101 provided on the substrate 100 via communication lines.

[0043] The water level sensor 63 is, for example, a float sensor, and outputs a water level signal, which is a signal related to the detection result of the water level stored in the drain pan 6, to the control unit 101. The flow rate sensor 77 and the tank flow rate sensor 92 are, for example, impeller-type or clamp-on-type sensors. The flow rate sensor 77 outputs a first flow rate signal, which is a signal related to the detection result of the flow rate of water flowing in the supply water passage 7, to the control unit 101. The tank flow rate sensor 92 outputs a second flow rate signal, which is a signal related to the detection result of the flow rate of water flowing in the replenishment water passage 9, to the control unit 101.

[0044] The control unit 101 determines whether the water level in the drain pan 6 is below a predetermined value based on the water level signal obtained from the water level sensor 63, and if it determines that the water level is below the predetermined value, it drives the tank pump 91 to replenish water from the water tank 8 to the drain pan 6. Note that the predetermined value is, for example, a value corresponding to the upper limit of the allowable water amount of the drain pan 6. The control unit 101 may also detect a malfunction or determine whether the water tank 8 is empty based on the first flow rate signal and the second flow rate signal from the flow rate sensor 77 and the tank flow rate sensor 92.

[0045] A microcomputer including a memory and an MPU may be mounted on the substrate 100, and the microcomputer may function as the control unit 101. The memory stores programs executed by the control unit 101 and parameters such as setting values ​​for executing the programs. The microcomputer functioning as the control unit may include an input / output interface. In this case, the input / output interface functions as an input unit that receives signals from the air supply fan 41, the exhaust fan 51, the water level sensor 63, the flow rate sensor 77, and the tank flow rate sensor 92. The input / output interface also functions as an output unit that outputs control signals to the air supply fan 41, the exhaust fan 51, the water supply pump 76, and the tank pump 91.

[0046] 6 and 7 are flowcharts showing the processing procedure performed by the control unit 101. The control unit 101 mounted on the substrate 100 performs the following processing when the air conditioner 1 performs air conditioning operation, for example.

[0047] When the main power supply of the air conditioner 1 is turned ON, the control unit 101 drives the water supply pump 76 (S101). By driving the water supply pump 76, water stored in the drain pan 6 is supplied to the filter water supply unit 21 and the heat exchange water supply unit 33 via the supply water passage 7. When driving the water supply pump 76, the control unit 101 may keep the tank pump 91 stopped.

[0048] The control unit 101 determines whether or not there is water stored in the drain pan 6 based on the first flow rate signal from the flow rate sensor 77 (S102). The control unit 101 acquires the first flow rate signal, for example, a pulse signal, from the flow rate sensor 77. The control unit 101 may count the number of acquired pulse signals while the water supply pump 76 is being driven, and if the count value, that is, the integrated number of pulses, is equal to or greater than a predetermined number of pulses, determine that water is flowing in the supply water channel 7 in which the flow rate sensor 77 is disposed and that there is water stored in the drain pan 6. The control unit 101 may also determine that there is no water stored in the drain pan 6 if the integrated number of pulses is less than the predetermined number of pulses.

[0049] The control unit 101 drives the water supply pump 76 and keeps the tank pump 91 stopped when determining whether or not water is stored in the drain pan 6 based on the first flow rate signal from the flow rate sensor 77. When driving the water supply pump 76, the control unit 101 stops the tank pump 91, and therefore stops the supply of water from the water tank 8 to the drain pan 6. This prevents the water level in the drain pan 6 from becoming unstable, ensures the detection accuracy of the water level sensor 63, and reduces the risk of water leakage from the drain pan 6 caused by, for example, erroneous detection by the water level sensor 63.

[0050] If it is determined that there is water stored in the drain pan 6 (S102: YES), the control unit 101 drives the water supply pump 76 for a predetermined period of time and then stops it (S103). After the predetermined period has elapsed since the water supply pump 76 was stopped, the control unit 101 performs a loop process to execute the process of S101 again. By repeating this loop process, the tank pump 91 is kept stopped and the water supply pump 76 is continuously or intermittently driven until it is determined that there is no water stored in the drain pan 6. This reduces the cumulative driving time without excessively operating the tank pump 91, and improves the service life of the tank pump 91.

[0051] If it is determined that there is no water stored in the drain pan 6 (S102: NO), the control unit 101 determines whether the water level in the drain pan 6 is below a predetermined water level based on the water level signal from the water level sensor 63 (S104). The water level sensor 63 is configured, for example, with a float switch, and if the water level in the drain pan 6 is below a predetermined value, it outputs a water level signal indicating that the float switch is off, i.e., an OFF signal. In this case, the water level sensor 63 is in a float OFF state. If the water level in the drain pan 6 is above a predetermined value, the water level sensor 63 outputs a water level signal indicating that the float switch is on, i.e., an ON signal. In this case, the water level sensor 63 is in a float ON state.

[0052] If the water level in the drain pan 6 is not equal to or lower than the predetermined water level (S104: NO), i.e., if an ON signal is output, the control unit 101 detects an abnormality (S1041). In this case, although the first flow rate signal from the flow rate sensor 77 indicates that there is no water stored in the drain pan 6, the water level signal from the water level sensor 63 is an ON signal, indicating that the water level in the drain pan 6 is higher than the predetermined water level and that there is water stored in the drain pan 6. In other words, the detection result of the flow rate sensor 77 and the detection result of the water level sensor 63 are inconsistent, and in this case, the control unit 101 determines that some abnormality has occurred in the supply water passage 7 or the refill water passage 9.

[0053] If it is determined that there is no water stored in the drain pan 6 based on the first flow rate signal from the flow rate sensor 77 (S102: NO), and further if the water level in the drain pan 6 is below a predetermined water level (S104: YES), that is, if the water level sensor 63 outputs an OFF signal, the control unit 101 drives the tank pump 91 (S105). By driving the tank pump 91, water is supplied from the water tank 8 to the drain pan 6 via the replenishment water passage 9. The control unit 101 may keep the water supply pump 76 stopped when driving the tank pump 91.

[0054] The control unit 101 determines whether the water level in the drain pan 6 is equal to or lower than a predetermined water level based on the water level signal from the water level sensor 63 (S106). As described above, if the water level in the drain pan 6 is equal to or lower than the predetermined water level, the control unit 101 acquires an OFF signal from the water level sensor 63. If the water level in the drain pan 6 is higher than the predetermined water level, the control unit 101 acquires an ON signal from the water level sensor 63.

[0055] If the water level in the drain pan 6 is not below the predetermined water level (S106: NO), that is, if an ON signal is acquired, the control unit 101 stops the tank pump 91 (S1061). The ON signal from the water level sensor 63 indicates that the water level in the drain pan 6 is higher than the predetermined water level, and in this case, the water level sensor 63 is in the float ON state. The control unit 101 stops the tank pump 91 when an ON signal is acquired.

[0056] This reliably prevents excessive water from being supplied to the drain pan 6 and causing water to leak from the drain pan 6. The control unit 101 may stop the tank pump 91 when the operating time of the tank pump 91 reaches a predetermined maximum operating time even if it does not receive an ON signal, i.e., even if an OFF signal is output from the water level sensor 63. The maximum operating time is pre-stored in a memory or the like accessible by the control unit 101, which is configured by a microcomputer or the like. In this way, even if the float is in the OFF state and the OFF signal is output from the water level sensor 63, the tank pump 91 is stopped when the operating time of the tank pump 91 exceeds the maximum operating time. Therefore, even if the water level sensor 63 is malfunctioning, for example, water can be reliably prevented from leaking from the drain pan 6.

[0057] The control unit 101 drives the water supply pump 76 (S1062). The control unit 101 determines whether water is stored in the drain pan 6 based on the first flow rate signal from the flow rate sensor 77 (S1063). If it is determined that water is stored in the drain pan 6 (S1063: YES), the control unit 101 performs loop processing to execute S103 again. As long as water remains in the water tank 8, the loop processing is repeated, whereby the water supply pump 76 and the tank pump 91 are intermittently driven, and the water stored in the drain pan 6 is supplied to the filter water supply unit 21 and the heat exchanger water supply unit 33.

[0058] If it is determined that there is no water stored in the drain pan 6 (S1063: NO), the control unit 101 detects an abnormality (S1064). In this case, although the first flow rate signal from the flow rate sensor 77 indicates that there is no water stored in the drain pan 6, the water level signal from the water level sensor 63 is an ON signal, and the water level in the drain pan 6 is higher than the predetermined water level, indicating that there is water stored in the drain pan 6. In other words, the detection result of the flow rate sensor 77 and the detection result of the water level sensor 63 are inconsistent, and in this case, the control unit 101 determines that some abnormality has occurred in the supply water passage 7 or the replenishment water passage 9.

[0059] If the water level in the drain pan 6 is below a predetermined level (S106: YES), that is, if an OFF signal is acquired, the control unit 101 determines whether the amount of water supplied from the drain pan 6 is below a predetermined value based on the first flow rate signal from the flow rate sensor 77 (S107). The control unit 101 drives the water supply pump 76 for a predetermined period and acquires the first flow rate signal from the flow rate sensor 77. As described above, even if the float is OFF and an OFF signal is output from the water level sensor 63, if the driving time of the tank pump 91 exceeds the maximum driving time, the control unit 101 stops the tank pump 91. Therefore, when the water supply pump 76 is driven in this process, the tank pump 91 is stopped.

[0060] The control unit 101 may count the number of acquired pulse signals during the driving period of the water supply pump 76, and determine whether the amount of water supplied from the drain pan 6 is equal to or less than a predetermined value depending on whether the count value, that is, the integrated number of pulses, is equal to or less than a predetermined number. If the integrated number of pulses is equal to or greater than the predetermined number of pulses, the control unit 101 may determine that water is flowing in the water supply channel 7 in which the flow rate sensor 77 is disposed, and therefore the water tank 8 is not empty. If the integrated number of pulses is less than the predetermined number of pulses, the control unit 101 may determine that the water tank 8 is empty.

[0061] If the amount of water supplied from the drain pan 6 is equal to or less than a predetermined value (S107: YES), the control unit 101 determines that the water tank 8 is empty and places the air conditioner 1 in the air blowing operation state (S108). Thus, if the output signal from the water level sensor 63 indicates that the water level in the drain pan 6 is equal to or less than a predetermined level after driving the tank pump 91 for a predetermined time, the control unit 101 drives the water supply pump 76. After driving the water supply pump 76 for a predetermined time, the control unit 101 determines whether water remains in the water tank 8 based on the output signal from the flow rate sensor 77, thereby ensuring the accuracy of the determination. The control unit 101 places the air conditioner 1 in the air blowing operation state by driving the air supply fan and exhaust fan while keeping the water supply pump 76 and the tank pump 91 stopped. If it is determined that there is no water remaining in the water tank 8, the control unit 101 keeps the water supply pump 76 stopped, thereby preventing the water supply pump 76 from being driven excessively.

[0062] If the amount of water supplied from the drain pan 6 is not equal to or less than the predetermined value (S107: NO), the control unit 101 drives the water supply pump 76 (S109). The control unit 101 determines whether water is stored in the drain pan 6 based on the first flow rate signal from the flow rate sensor 77 (S110). The control unit 101 determines whether water is stored in the drain pan 6 based on the first flow rate signal from the flow rate sensor 77, as in S102 and S1063.

[0063] If it is determined that there is water stored in the drain pan 6 (S110: YES), the control unit 101 stops the water supply pump 76 (S111). After a predetermined period of time has elapsed since the water supply pump 76 was stopped, the control unit 101 performs a loop process to execute the process of S109 again. By repeating this loop process, it is possible to use up all the water stored in the drain pan 6. In other words, because the water tank 8 is empty, the tank pump 91 is kept stopped while the water supply pump 76 is continuously or intermittently driven, so that the water stored in the drain pan 6 can be used up until the drain pan 6 is empty, and the air conditioner 1 can continue cooling operation to the maximum extent possible.

[0064] If it is determined that there is no water stored in the drain pan 6 (S110: NO), the control unit 101 drives the tank pump 91 (S112). When driving the tank pump 91, the control unit 101 stops the water supply pump 76. The control unit 101 drives the tank pump 91 until it receives an ON signal from the water level sensor 63 or until the driving time of the tank pump 91 reaches the maximum driving time.

[0065] The control unit 101 determines whether the amount of water supplied from the drain pan 6 is equal to or less than a predetermined value based on the first flow rate signal from the flow rate sensor 77 (S113). If the amount of water supplied from the drain pan 6 is not equal to or less than the predetermined value (S113: NO), the control unit 101 detects an abnormality (S1131).

[0066] If the amount of water supplied from the drain pan 6 is equal to or less than the predetermined value (S113: YES), the control unit 101 determines that the water tank 8 is empty and places the air conditioner 1 in the air blowing operation state (S114). By retrying the operation by driving the tank pump 91 again and then detecting the amount of water supplied from the drain pan 6 again based on the first flow rate signal from the flow rate sensor 77, it is possible to reliably determine that the water tank 8 is empty. That is, after the output signal from the flow rate sensor 77 indicates that the flow rate of water flowing from the drain pan 6 to the water supply unit is equal to or less than the predetermined flow rate, the control unit 101 stops driving the water supply pump 76 and drives the tank pump 91 for a predetermined period, such as 30 seconds, thereby restarting the tank pump 91 even if it was determined that the water tank 8 was empty. After restarting the tank pump 91, the control unit 101 again determines whether the water tank 8 is empty based on the output signal from the flow rate sensor 77, thereby ensuring the accuracy of the determination.

[0067] The control unit 101 changes the drive state of the tank pump 91 based on the water level signal output from the water level sensor 63 and the first flow rate signal output from the flow rate sensor 77, and therefore can prevent water from leaking from the drain pan 6 more effectively than, for example, controlling the drive of the tank pump 91, such as by turning it on or off, using only the water level sensor 63. By combining the water level sensor 63 and the flow rate sensor 77 in this way, the risk of water leakage from the drain pan 6 can be reduced, and the amount of circulating water recovered in the drain pan 6 after being supplied from the drain pan 6 to the water supply unit can be minimized. Furthermore, the amount of water supplied from the water tank 8 to the drain pan 6 can be reduced, which reduces the drive frequency of the tank pump 91 and extends its useful life.

[0068] (Embodiment 2) 8 and 9 are flowcharts showing the processing procedure by the control unit 101 according to the second embodiment. The control unit 101 mounted on the substrate 100 performs the following processing, for example, when the air conditioner 1 performs air conditioning operation. The second embodiment differs from the first embodiment in that the control unit 101 performs various processing based on a second flow rate signal output from the tank flow rate sensor 92. The control unit 101 performs the processing from S201 to S2064, similar to S101 to S1064 in the first embodiment.

[0069] As in S105 of the first embodiment described above, after executing the process of S205, the control unit 101 determines whether the water level in the drain pan 6 is equal to or lower than a predetermined water level based on the water level signal from the water level sensor 63 (S206). If the water level in the drain pan 6 is not equal to or lower than the predetermined water level (S206: NO), that is, if an ON signal is acquired, the control unit 101 stops the tank pump 91 (S2061), similar to S1061 of the first embodiment. The subsequent processes are the same as those in the first embodiment.

[0070] If the water level in the drain pan 6 is below a predetermined level (S206: YES), i.e., if an OFF signal is received, the control unit 101 determines whether the amount of water supplied from the water tank 8 to the drain pan 6 is equal to or greater than a first predetermined value based on a second flow rate signal from the tank flow rate sensor 92 (S207). The control unit 101 receives the second flow rate signal, for example, a pulse signal, from the tank flow rate sensor 92. The control unit 101 may count the number of received pulse signals while the tank pump 91 is being driven, and if the count value, that is, the integrated number of pulses, is equal to or greater than a predetermined number of pulses, determine that water is flowing in the refill water passage 9 in which the tank flow rate sensor 92 is disposed and that the amount of water supplied from the water tank 8 to the drain pan 6 is equal to or greater than the first predetermined value.

[0071] If the amount of water supplied from the water tank 8 to the drain pan 6 is equal to or greater than the first predetermined value (S207: YES), the control unit 101 detects an abnormality (S2071). The first predetermined value used in the determination of S207 is set, for example, as a value corresponding to the upper limit of the allowable water volume of the water tank 8 and is greater than a second predetermined value used to determine whether the water tank 8 is empty, as described below. If the second flow rate signal from the tank flow rate sensor 92 indicates that the amount of water supplied from the water tank 8 to the drain pan 6 is equal to or greater than the first predetermined value, it is assumed, based only on the second flow rate signal, that sufficient water is being supplied from the water tank 8 to the drain pan 6 and that the water level in the drain pan 6 is greater than the predetermined level. However, the determination process of S207 is performed when the process of S206 determines that the water level in the drain pan 6 is equal to or less than the predetermined level (S206: YES). In other words, the water level signal from the water level sensor 63 indicates that the water level in the drain pan 6 is equal to or less than the predetermined level. In this case, for example, there is a concern that the water level sensor 63 may be stuck in a state where the float is always OFF, causing an abnormality that causes it to constantly erroneously determine that there is no water. In this way, the detection results of the water level sensor 63 and the tank flow rate sensor 92 may be inconsistent, and the control unit 101 may determine that some abnormality has occurred in the water level sensor 63 or the like.

[0072] If the amount of water supplied from the water tank 8 to the drain pan 6 is not equal to or greater than the first predetermined value (S207: NO), that is, if the amount of water is less than the first predetermined value, the control unit 101 determines whether the amount of water supplied from the water tank 8 to the drain pan 6 is equal to or less than a second predetermined value that is smaller than the first predetermined value, based on the second flow rate signal from the tank flow rate sensor 92 (S208). The second predetermined value is set to a value smaller than the first predetermined value, and is stored in the memory unit.

[0073] If the amount of water supplied from the water tank 8 to the drain pan 6 is equal to or less than the second predetermined value (S208: YES), the control unit 101 determines that the water tank 8 is empty and sets the air conditioner 1 to the air blowing operation state (S2081). The control unit 101 sets the air conditioner 1 to the air blowing operation state by driving the air supply fan and the exhaust fan while keeping the water supply pump 76 and the tank pump 91 stopped. In this way, the control unit 101 acquires the second flow rate signal output from the tank flow rate sensor 92 and determines whether water remains in the water tank 8 based on the acquired output signal, so that the presence or absence of water in the water tank 8 can be efficiently determined.

[0074] If the amount of water supplied from the water tank 8 to the drain pan 6 is not equal to or less than the second predetermined value (S208: NO), that is, if the amount of water supplied is greater than the second predetermined value and less than the first predetermined value, the control unit 101 drives the water supply pump 76 (S209). The control unit 101 determines whether water is stored in the drain pan 6 based on a first flow rate signal from the flow rate sensor 77 (S210). The control unit 101 determines whether water is stored in the drain pan 6 based on the first flow rate signal from the flow rate sensor 77, similar to S102 etc. in the first embodiment.

[0075] If it is determined that there is no water stored in the drain pan 6 (S210: NO), the control unit 101 detects an abnormality (S2101). In this case, the detection result of the flow rate sensor 77 and the detection result of the tank flow rate sensor 92 are inconsistent, and the control unit 101 determines that some abnormality has occurred in the supply water passage 7 or the replenishment water passage 9.

[0076] If it is determined that there is water stored in the drain pan 6 (S210: YES), the control unit 101 performs a loop process to execute the process of S203 again. By repeating this loop process, even if the water tank 8 has run out of water, the water stored in the drain pan 6 can be used up.

[0077] Multiple claims may be combined with each other regardless of the form of reference. Multiple dependent claims may be included in the claims, depending on multiple claims. Multiple dependent claims may be included in a multiple dependent claim. If multiple dependent claims are not included in a multiple dependent claim, this does not limit the number of multiple dependent claims that are included in a multiple dependent claim.

[0078] The embodiments disclosed herein are to be considered as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0079] 1 Air conditioner 100 boards 101 Control section 10. Cabinet 11 Main unit 111 First side wall 1111 First side wall of the main body 1112 Door side first side wall 112 Second side wall 113 Third Side Wall 114 4th side wall 115 Support part 116 Tank base 118 Handle 12 Doors 20 Cooling Unit 2 Evaporative filters 21 Filter water supply unit (water supply unit) 3. Sensible heat exchanger 31 Air supply route 32 Exhaust route 33 Heat exchange water supply section (water supply section) 4 Air supply channel 41 Air supply fan 42 Air intake port 43 Air supply outlet 431 Duct 432 Wind direction adjustment plate 44 First intermediate air supply passage 5 Exhaust flow path 51 Exhaust fan 52 Exhaust intake port 53 Exhaust outlet 6 Drain pan 61 bottom 611 Bottom hole 62 Wall 621 Water supply hole 63 Water level sensor 7 Supply waterway 71 First water supply channel 72 Second water supply channel 73 Connected water supply channel 74 Water supply connection road 75 Drain pan filter 76 Water supply pump 77 Flow Sensor 78 Branch 781 Drainage Channel 8. Water Tank 82 Water level check window 9 Refill waterway 91 Tank pump 92 Tank flow sensor

Claims

1. A cooling unit; a water supply unit that supplies water to the cooling unit; a drain pan that stores water dripping from the cooling unit and is connected to the water supply unit via a supply water channel; a water tank connected to the drain pan; a water supply pump that supplies water from the drain pan to the water supply section; a tank pump for supplying water from the water tank to the drain pan; a flow rate sensor disposed in the supply water channel and configured to detect the flow rate of water flowing from the drain pan to the water supply section; a water level sensor disposed in the water storage space of the drain pan; a control unit that controls the drive of the water supply pump and the tank pump, The control unit Acquire output signals output from the water level sensor and the flow rate sensor; Based on the acquired output signal, the driving state of the tank pump is changed. An air conditioner characterized by:

2. The control unit drives the tank pump when the output signal from the flow rate sensor indicates that the flow rate of water flowing from the drain pan to the water supply unit is equal to or less than a predetermined flow rate value and when the output signal from the water level sensor indicates that the water level in the drain pan is equal to or less than a predetermined water level.

2. The air conditioner according to claim 1.

3. The control unit stops the tank pump when driving the water supply pump.

3. The air conditioner according to claim 2.

4. The control unit After driving the tank pump for a predetermined time, if an output signal from the water level sensor indicates that the water level in the drain pan is equal to or lower than a predetermined water level, driving the water supply pump; After the water supply pump has been driven for a predetermined time, it is determined whether water remains in the water tank based on an output signal from the flow rate sensor.

3. The air conditioner according to claim 2.

5. When the control unit determines that there is no water remaining in the water tank, the control unit maintains the stopped state of the water supply pump.

5. The air conditioner according to claim 4.

6. When the control unit determines that there is no water remaining in the water tank, the control unit continues to drive the water supply pump until an output signal from the flow rate sensor indicates that the flow rate of water flowing from the drain pan to the water supply unit is equal to or less than a predetermined flow rate value.

6. The air conditioner according to claim 5.

7. The control unit stops driving the water supply pump when the output signal from the flow rate sensor indicates that the flow rate of water flowing from the drain pan to the water supply unit is equal to or less than a predetermined flow rate value, and then drives the tank pump for a predetermined period of time.

7. The air conditioner according to claim 6.

8. a tank flow rate sensor is disposed in a replenishment water passage connecting the drain pan and the water tank; The control unit Acquire an output signal output from the tank flow rate sensor; Based on the acquired output signal, it is determined whether water remains in the water tank.

4. The air conditioner according to claim 1, wherein the first and second electrodes are electrically connected to the first and second electrodes.

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