air conditioner

Abstract

To reduce a load applied to components of an air conditioner.SOLUTION: An air conditioner (10) in one embodiment includes an indoor unit (20) and an outdoor unit (30). The air conditioner includes: an absorber (52) provided in the outdoor unit and absorbing moisture of outdoor air; a flow passage (P1) that passes through the absorber and connects an outdoor side with inside of the indoor unit and in which outdoor air flows; a first heater (58) and a second heater (60) heating outdoor air on the upstream side of the absorber in the flow passage; and a control section (90) controlling turning on / off of the first heater and the second heater. In the control section (90), first timing (tmg1) of switching the first heater to the on state and second timing (tmg2) of switching the second heater to the on state are set different from each other.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] Conventionally, there has been known an air conditioner that is configured with an indoor unit that is placed inside a room to be air-conditioned and an outdoor unit that is placed outside the room, as described in Patent Document 1. This air conditioner is configured so that humidified outdoor air can be supplied from the outdoor unit to the indoor unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-91000 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, there is a need to reduce the load on the components of air conditioners.

[0005] Therefore, an object of the present disclosure is to provide an air conditioner that can reduce the load on the components of the air conditioner. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, according to one aspect of the present invention, An air conditioner comprising an indoor unit and an outdoor unit, an absorbent material provided in the outdoor unit that absorbs moisture in the outdoor air; a flow path through which outdoor air flows, the flow path passing through the absorbent material, connecting the outside of the room with the inside of the indoor unit; a first heater and a second heater that heat the outdoor air upstream of the absorbent material in the flow path; a control unit that controls on / off of the first heater and the second heater; Equipped with In the air conditioner, the control unit differentiates a first timing at which the first heater is switched on from a second timing at which the second heater is switched on. [Effects of the Invention]

[0007] According to the present disclosure, an air conditioner is provided that can reduce the load on the components of the air conditioner. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure; [Figure 2] Schematic diagram of ventilation system [Figure 3] Schematic diagram of the ventilation system during ventilation operation [Figure 4] Schematic diagram of ventilation system during humidification operation [Figure 5] Schematic diagram of ventilation system during dehumidification operation [Figure 6] Schematic diagram of the first heater and the second heater and their surroundings [Figure 7] Schematic diagram showing control for suppressing inrush current [Figure 8] Schematic diagram to explain the characteristics of a PTC heater [Figure 9A] Schematic diagram explaining the heater current flowing through a PTC heater in the negative characteristic region [Figure 9B] Schematic diagram explaining the heater current flowing through a PTC heater in the negative characteristic region [Figure 10] Schematic diagram explaining the heater current flowing through a PTC heater in the positive characteristic region [Figure 11] Schematic illustrating relay control, fan speed control, heater current and heater temperature [Figure 12] Schematic diagram illustrating relay control according to Modification 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] An air conditioner according to one embodiment of the present invention is an air conditioner comprising an indoor unit and an outdoor unit, and comprising: an absorbent material provided in the outdoor unit for absorbing moisture in the outdoor air; a flow path through which the outdoor air flows, passing through the absorbent material and connecting the outdoors with the interior of the indoor unit; a first heater and a second heater for heating the outdoor air upstream of the absorbent material in the flow path; and a control unit for controlling the on / off of the first heater and the second heater, wherein the control unit differentiates between a first timing for switching on the first heater and a second timing for switching on the second heater.

[0010] According to this aspect, the load on the components of the air conditioner can be reduced.

[0011] For example, the air conditioner may further include a first relay that switches the first heater on and off, and a second relay that switches the second heater on and off, and the control unit may control the switching timing for switching the first relay and the second relay on and off, and shift the first timing and the second timing.

[0012] For example, the second timing may be a timing when a first waiting time has elapsed since the first timing.

[0013] For example, the first waiting time may be not less than 15 seconds and not more than 45 seconds.

[0014] For example, the air conditioner may further include a common relay that controls the current flowing through the first relay and the second relay, and the control unit may switch the common relay on and off before switching the first relay and the second relay on and off.

[0015] For example, the air conditioner may further include a fan that generates a flow of outdoor air in the flow path toward the indoor unit, and the first heater and the second heater may each be a PTC (Positive Temperature Coefficient) heater.

[0016] For example, before switching on the first heater and the second heater, the control unit may control the fan to cool the first heater and the second heater by blowing air from the fan.

[0017] For example, the control unit may reduce the fan speed of the fan before the first timing and the second timing.

[0018] For example, the control unit may increase the fan speed of the fan after a second waiting time has elapsed from the second timing.

[0019] For example, the second waiting time may be not less than 15 seconds and not more than 45 seconds.

[0020] For example, the controller may reduce the fan speed before switching off at least one of the first heater and the second heater.

[0021] For example, the control unit may alternately switch on the first relay and the second relay.

[0022] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0023] FIG. 1 is a schematic diagram of an air conditioner according to an embodiment of the present disclosure.

[0024] As shown in FIG. 1, an air conditioner 10 according to this embodiment has an indoor unit 20 arranged in a room Rin to be air-conditioned, and an outdoor unit 30 arranged in an outdoor room Rout.

[0025] The indoor unit 20 is provided with an indoor heat exchanger 22 that exchanges heat with the indoor air A1, and a fan 24 that draws the indoor air A1 into the indoor unit 20 and blows the indoor air A1 into the room Rin after heat exchange with the indoor heat exchanger 22.

[0026] The outdoor unit 30 is provided with an outdoor heat exchanger 32 that exchanges heat with outdoor air A2, and a fan 34 that draws the outdoor air A2 into the outdoor unit 30 and blows the outdoor air A2 out to the outdoor Rout after exchanging heat with the outdoor heat exchanger 32. The outdoor unit 30 is also provided with a compressor 36, an expansion valve 38, and a four-way valve 40 that execute a refrigeration cycle with the indoor heat exchanger 22 and the outdoor heat exchanger 32.

[0027] The indoor heat exchanger 22, the outdoor heat exchanger 32, the compressor 36, the expansion valve 38, and the four-way valve 40 are each connected by a refrigerant pipe through which a refrigerant flows. In cooling operation and dehumidification operation (weak cooling operation), the air conditioner 10 executes a refrigeration cycle in which the refrigerant flows from the compressor 36 through the four-way valve 40, the outdoor heat exchanger 32, the expansion valve 38, and the indoor heat exchanger 22 in that order, before returning to the compressor 36. In heating operation, the air conditioner 10 executes a refrigeration cycle in which the refrigerant flows from the compressor 36 through the four-way valve 40, the indoor heat exchanger 22, the expansion valve 38, and the outdoor heat exchanger 32 in that order, before returning to the compressor 36.

[0028] In addition to air conditioning operation using a refrigeration cycle, the air conditioner 10 also performs air conditioning operation in which outdoor air A3 is introduced into the room Rin. To this end, the air conditioner 10 has a ventilation device 50. The ventilation device 50 is provided in the outdoor unit 30.

[0029] FIG. 2 is a schematic diagram of a ventilation system.

[0030] As shown in FIG. 2, the ventilation device 50 includes an absorbent material 52 therein through which the outdoor air A3 and A4 passes.

[0031] The absorbent material 52 is a member through which air can pass and which collects moisture from the air passing through it or adds moisture to the air passing through it. In this embodiment, the absorbent material 52 is disk-shaped and rotates around a rotation center line C1 that passes through the center of the absorbent material 52. The absorbent material 52 is rotationally driven by a motor 54.

[0032] The absorbent 52 is preferably a polymeric adsorbent that adsorbs moisture in the air. The polymeric adsorbent is, for example, composed of cross-linked sodium polyacrylate. Compared to adsorbents such as silica gel and zeolite, the polymeric adsorbent absorbs a larger amount of moisture per volume, can desorb the moisture it holds at a low heating temperature, and can hold the moisture for a long period of time.

[0033] Inside the ventilation device 50, a first flow path P1 and a second flow path P2 are provided, through which the outdoor air A3 and A4 flow, respectively, passing through the absorbent material 52. The first flow path P1 and the second flow path P2 pass through the absorbent material 52 at different positions.

[0034] The first flow path P1 is a flow path through which the outdoor air A3 flows toward the indoor unit 20. The outdoor air A3 flowing through the first flow path P1 is supplied into the indoor unit 20 via a ventilation duct 56.

[0035] In this embodiment, the first flow path P1 includes a plurality of branch flow paths P1a, P1b on the upstream side of the absorbent material 52. In this specification, the terms "upstream" and "downstream" are used with respect to the flow of air.

[0036] The plurality of tributary channels P1a, P2a join together upstream of the absorbent material 52. The plurality of tributary channels P1a, P1b are provided with first and second heaters 58, 60, respectively, that heat the outside air A3.

[0037] The first and second heaters 58, 60 may have the same heating capacity or different heating capacities. The first and second heaters 58, 60 are preferably PTC (Positive Temperature Coefficient) heaters, which increase electrical resistance as current flows and the temperature rises, thereby preventing excessive increases in heating temperature. In the case of a PTC heater, the heater itself adjusts the heating temperature within a certain temperature range, eliminating the need to monitor the heating temperature.

[0038] The first flow path P1 is provided with a first fan 62 that generates a flow of outdoor air A3 toward the indoor unit 20. In the present embodiment, the first fan 62 is disposed downstream of the absorbent material 52. When the first fan 62 is operated, the outdoor air A3 flows from the outdoor Rout into the first flow path P1 and passes through the absorbent material 52.

[0039] The first flow path P1 is provided with a damper device 64 that distributes the outdoor air A3 flowing through the first flow path P1 to the room Rin (i.e., the indoor unit 20) or the outdoor Rout. In the present embodiment, the damper device 64 is disposed downstream of the first fan 62. The outdoor air A3 distributed to the indoor unit 20 by the damper device 64 enters the indoor unit 20 via the ventilation duct 56 and is blown out into the room Rin by the fan 24.

[0040] The second flow path P2 is a flow path through which the outdoor air A4 flows. Unlike the outdoor air A3 flowing through the first flow path P1, the outdoor air A4 flowing through the second flow path P2 does not head toward the indoor unit 20. The outdoor air A4 flowing through the second flow path P2 passes through the absorbent material 52 and then flows out to the outdoor Rout.

[0041] A second fan 66 that generates a flow of outdoor air A4 is provided in the first flow path P1. In the present embodiment, the second fan 66 is disposed downstream of the absorbent material 52. When the second fan 66 is operated, the outdoor air A4 flows from the outdoor Rout into the second flow path P2, passes through the absorbent material 52, and then flows out to the outdoor Rout.

[0042] The ventilation device 50 selectively performs ventilation operation, humidification operation, and dehumidification operation by selectively using an absorbent material 52, a motor 54, a first heater 58, a second heater 60, a first fan 62, a damper device 64, and a second fan 66.

[0043] FIG. 3 is a schematic diagram of the ventilation device during ventilation operation.

[0044] Ventilation operation is an air conditioning operation in which the outdoor air A3 is supplied directly to the room Rin (i.e., the indoor unit 20) via the ventilation duct 56. As shown in FIG. 3, during ventilation operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are in the OFF state and do not heat the outdoor air A3. The first fan 62 is in the ON state, thereby causing the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the indoor unit 20. The second fan 66 is in the OFF state, thereby causing no flow of outdoor air A4 to occur through the second flow path P2.

[0045] According to this ventilation operation, the outdoor air A3 flows into the first flow path P1 and passes through the absorbent material 52 without being heated by the first and second heaters 58, 60. The outdoor air A3 that has passed through the absorbent material 52 is distributed to the indoor unit 20 by the damper device 64. The outdoor air A3 that has passed through the damper device 64 and reached the indoor unit 20 via the ventilation duct 56 is blown out into the room Rin by the fan 24. According to this ventilation operation, the outdoor air A3 is supplied as is to the room Rin, and the room Rin is ventilated.

[0046] FIG. 4 is a schematic diagram of the ventilation device during humidification operation.

[0047] The humidification operation is an air conditioning operation in which the outdoor air A3 is humidified and the humidified outdoor air A3 is supplied to the room Rin (i.e., the indoor unit 20). As shown in FIG. 4, during the humidification operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are in the ON state and heat the outdoor air A3. The first fan 62 is in the ON state, thereby causing the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the indoor unit 20. The second fan 66 is in the ON state, thereby causing the outdoor air A4 to flow through the second flow path P2.

[0048] In this humidification operation, the outdoor air A3 flows into the first flow path P1, is heated by the first and second heaters 58, 60, and passes through the absorbent 52. At this time, the heated outdoor air A3 can remove a larger amount of moisture from the absorbent 52 than when the outdoor air A3 is not heated. As a result, the outdoor air A3 carries a larger amount of moisture. The outdoor air A3 that has passed through the absorbent 52 and carried a larger amount of moisture is distributed to the indoor unit 20 by the damper device 64. The outdoor air A3 that has passed through the damper device 64 and reached the indoor unit 20 via the ventilation duct 56 is blown into the room Rin by the fan 24. In this humidification operation, the outdoor air A3 carrying a larger amount of moisture is supplied to the room Rin, and the room Rin is humidified.

[0049] In addition, by turning off either the first heater 58 or the second heater 60, the amount of moisture that the outdoor air A3 removes from the absorbent material 52 can be reduced, i.e., a weak humidification operation can be performed in which the amount of humidification of the indoor air Rin is reduced.

[0050] As moisture is removed by the heated outdoor air A3, the water retention capacity of the absorbent 52 decreases, i.e., the absorbent 52 dries. When the absorbent 52 dries, the outdoor air A3 flowing through the first flow path P1 cannot remove moisture from the absorbent 52. To address this, the absorbent 52 removes moisture from the outdoor air A4 flowing through the second flow path P2. This keeps the water retention capacity of the absorbent 52 approximately constant, allowing the humidification operation to continue.

[0051] FIG. 5 is a schematic diagram of the ventilation device during dehumidification operation.

[0052] The dehumidifying operation is an air conditioning operation in which the outdoor air A3 is dehumidified and the dehumidified outdoor air A3 is supplied to the room Rin (i.e., the indoor unit 20). As shown in Fig. 5, in the dehumidifying operation, the adsorption operation and the regeneration operation are performed alternately.

[0053] The adsorption operation is an operation in which moisture contained in the outdoor air A3 is adsorbed onto the absorbent material 52, thereby dehumidifying the outdoor air A3. As shown in FIG. 5, during the adsorption operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are in the OFF state and do not heat the outdoor air A3. The first fan 62 is in the ON state, thereby causing the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the indoor unit 20. The second fan 66 is in the OFF state, thereby causing no flow of outdoor air A4 to occur through the second flow path P2.

[0054] During this adsorption operation, the outdoor air A3 flows into the first flow path P1 and passes through the absorbent 52 without being heated by the first and second heaters 58, 60. At this time, the moisture carried in the outdoor air A3 is adsorbed by the absorbent 52. This reduces the amount of moisture carried by the outdoor air A3, i.e., the outdoor air A3 is dried. The outdoor air A3 that has passed through the absorbent 52 and is then distributed to the indoor unit 20 by the damper device 64. The outdoor air A3 that has passed through the damper device 64 and reached the indoor unit 20 via the ventilation duct 56 is then blown into the room Rin by the fan 24. During this adsorption operation, the dried outdoor air A3 is supplied to the room Rin, and the room Rin is dehumidified.

[0055] As the adsorption operation continues, the amount of water held by the absorbent 52 continues to increase, resulting in a decrease in the absorbent 52's ability to adsorb the moisture contained in the outdoor air A3. In order to recover the adsorption ability, a regeneration operation is performed to regenerate the absorbent 52.

[0056] During regeneration operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are ON and heat the outdoor air A3. The first fan 62 is ON and causes the outdoor air A3 to flow through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the outdoor Rout rather than to the indoor unit 20. The second fan 66 is OFF and causes no flow of outdoor air A4 to occur in the second flow path P2.

[0057] According to this regeneration operation, the outdoor air A3 flows into the first flow path P1, is heated by the first and second heaters 58, 60, and passes through the absorbent 52. At this time, the heated outdoor air A3 removes a large amount of moisture from the absorbent 52. As a result, the outdoor air A3 carries a large amount of moisture. At the same time, the water retention capacity of the absorbent 52 decreases, that is, the absorbent 52 dries and its adsorption capacity is regenerated. The outdoor air A3 that has passed through the absorbent 52 and carries a large amount of moisture is diverted by the damper device 64 to the outdoor Rout and discharged to the outdoor Rout. As a result, during the regeneration operation in the dehumidification operation, the outdoor air A3 carrying a large amount of moisture due to the regeneration of the absorbent 52 is not supplied to the indoor Rin.

[0058] By alternately performing the adsorption operation and the regeneration operation in this manner, the adsorption capacity of the absorbent material 52 is maintained, and the dehumidification operation can be carried out continuously.

[0059] The above-mentioned air conditioning operations using the refrigeration cycle (cooling operation, dehumidifying operation (weak cooling operation), heating operation) and the air conditioning operations using the ventilation device 50 (ventilation operation, humidifying operation, dehumidifying operation) can be performed separately or simultaneously. For example, if the dehumidifying operation using the refrigeration cycle and the dehumidifying operation using the ventilation device 50 are performed simultaneously, it is possible to dehumidify the room Rin while maintaining the room temperature constant.

[0060] The user selects the air conditioning operation to be performed by the air conditioner 10. For example, when the user performs a selection operation on the remote controller 70 shown in Fig. 1, the air conditioner 10 performs the air conditioning operation corresponding to that operation.

[0061] Up to this point, we have given an overview of the configuration and operation of the air conditioner 10 according to this embodiment. From here on, we will explain further features of the air conditioner 10 according to this embodiment.

[0062] The structure for turning on and off the first heater 58 and the second heater 60 will be described.

[0063] FIG. 6 is a schematic diagram of the periphery of the first heater and the second heater.

[0064] 6, the on / off of the first heater 58 and the second heater 60 is controlled by a common relay 80, a first relay 82, and a second relay 84. The common relay 80, the first relay 82, and the second relay 84 are controlled by a control unit 90.

[0065] The common relay 80 controls the current flowing through the first relay 82 and the second relay 84 .

[0066] In this embodiment, the common relay 80 is arranged in the current path EP. One end of the current path EP is connected to the power supply, and the other end of the current path EP is connected to the heaters 58 and 60. The other end of the current path EP branches into a first current path EP1 and a second current path EP2 connected to the first heater 58. The first heater 58 and a first relay 82 are arranged in the first current path EP1. The second heater 60 and a second relay 84 are arranged in the second current path EP2. The current paths EP, EP1, and EP2 are, for example, wiring.

[0067] When the common relay 80 is on, the current Ih can flow through the first current path EP1 and the second current path EP2, whereas when the common relay 80 is off, the current Ih does not flow through the first current path EP1 and the second current path EP2.

[0068] When the common relay 80 is turned on, the first relay 82 switches the first heater 58 on and off. When the first relay 82 is turned on, the first heater 58 is turned on, and when the first relay 82 is turned off, the first heater 58 is turned off. Specifically, when the first relay 82 is turned on, a current Ih flows from the common relay 80 through the first current path EP1 to the first heater 58. This causes the first heater 58 to be energized and turned on. On the other hand, when the first relay 82 is turned off, the current Ih stops flowing from the common relay 80 to the first current path EP1. This causes the first heater 58 to stop being energized and turn off.

[0069] When the common relay 80 is turned on, the second relay 84 switches the second heater 60 on and off. When the second relay 84 is turned on, the second heater 60 is turned on, and when the second relay 84 is turned off, the second heater 60 is turned off. Specifically, when the second relay 84 is turned on, a current Ih flows from the common relay 80 to the second heater 60 through the second current path EP2. This causes the second heater 60 to be energized and turned on. On the other hand, when the second relay 84 is turned off, the current Ih stops flowing from the common relay 80 to the second current path EP2. This causes the second heater 60 to stop being energized and turn off.

[0070] For example, electromagnetic relays can be used for the first relay 82 and the second relay 84. With this configuration, compared to when the first relay 82 and the second relay 84 are configured using semiconductor switches, no heat dissipation member is required, and there are fewer restrictions on placement on the board.

[0071] The control unit 90 controls the common relay 80, the first relay 82, and the second relay 84 to control the on / off of the first heater 58 and the second heater 60. The control unit 90 differentiates the first timing tmg1 for switching on the first heater 58 from the second timing tmg2 for switching on the second heater 60. Specifically, the control unit 90 controls the on / off switching timing of the first relay 82 and the second relay 84 to differentiate the first timing tmg1 from the second timing tmg2. This configuration can prevent inrush currents from increasing in the first heater 58 and the second heater 60. This can prevent the inrush currents from exceeding the breaker capacity of the first heater 58 and the second heater 60. Furthermore, if the compressor performs current limitation taking inrush current into consideration, suppressing the increase in inrush current can reduce the impact on the compressor.

[0072] Furthermore, the control unit 90 switches the common relay 80 on and off before switching the first relay 82 and the second relay 84 on and off. Specifically, the control unit 90 switches the common relay 80 on before switching the first relay 82 or the second relay 84 on. The control unit 90 switches the common relay 80 off before switching the first relay 82 and the second relay 84 off. This allows the stress (load) on the first relay 82 and the second relay 84 to be distributed by the common relay 80. As a result, the lifespan of the first relay 82 and the second relay 84 can be extended.

[0073] In a relay, the operation of turning on and off the relay, which causes current to flow and break, is likely to cause stress. For example, the control unit 90 turns off the common relay 80 before turning off the first relay 82 and the second relay 84. This allows the first relay 82 and the second relay 84 to be turned off when no current is flowing through them. As a result, the stress (load) on the first relay 82 and the second relay 84 can be reduced, and the life of the first relay 82 and the second relay 84 can be extended.

[0074] The control unit 90 includes, for example, a memory that stores a program and a processing circuit corresponding to a processor such as a CPU (Central Processing Unit). The functions of the control unit 90 may be configured solely by hardware, or may be realized by combining hardware and software. The control unit 90 realizes predetermined functions by reading data and programs stored in the memory and performing various arithmetic processing.

[0075] 7A and 7B are schematic diagrams showing control for suppressing inrush current, in which Fig. 7A is a schematic diagram of relay control in Example 1, and Fig. 7B is a graph showing inrush currents in Example 1 and Comparative Example 1.

[0076] As shown in FIG. 7A, in the first embodiment, when turning on the first heater 58 and the second heater 60, the control unit 90 turns on the common relay 80, the first relay 82, and the second relay 84 in that order. Specifically, the control unit 90 turns on the common relay 80 while the common relay 80, the first relay 82, and the second relay 84 are in an off state. After turning on the common relay 80, the control unit 90 turns on the first relay 82 at a first timing tmg1. The control unit 90 turns on the second relay 84 at a second timing tmg2, which is a predetermined period after the first timing tmg1. In this way, the control unit 90 staggers the timings at which the common relay 80, the first relay 82, and the second relay 84 are turned on.

[0077] In Comparative Example 1, the first relay 82 and the second relay 84 are switched on simultaneously. Specifically, in Comparative Example 1, the first relay 82 and the second relay 84 are switched on at the first timing tmg1.

[0078] As shown in FIG. 7(b), in Comparative Example 1, an inrush current occurs at the first timing tmg1. In Comparative Example 1, inrush currents occur simultaneously at the first timing tmg1 in the first heater 58 and the second heater 60. Therefore, since two inrush currents occur, the peak value of the inrush current tends to be large. On the other hand, in Example 1, an inrush current occurs in the first heater 58 at the first timing tmg1, and an inrush current occurs in the second heater 60 at the second timing tmg2. That is, in Example 1, the inrush currents occur dispersedly.

[0079] Comparing the magnitudes of the inrush currents between Example 1 and Comparative Example 1, the magnitude of the inrush current in Example 1 is smaller than the magnitude of the inrush current in Comparative Example 1. In the example of FIG. 7(b), the magnitudes of the inrush currents at the first timing tmg1 and the second timing tmg2 in Example 1 are approximately 1 / 2 times the magnitude of the inrush current at the first timing tmg1 in Comparative Example 1.

[0080] Thus, by shifting the first timing tmg1 for switching on the first relay 82 and the second timing tmg2 for switching on the second relay 84, the inrush current generated when the relay is turned on can be dispersed, and the peak value of the inrush current can be reduced.

[0081] Next, control using the characteristics of the PTC heater will be described.

[0082] FIG. 8 is a schematic diagram for explaining the characteristics of the PTC heater. In FIG. 8, the temperature T1 < T2, Tf1 < Tf2, the electrical resistance R1 > R2, Rf1 < Rf2, and the fan speed Vf1 > Vf2. Also, "border" indicates the boundary between the negative characteristic region and the positive characteristic region.

[0083] As shown in Figure 8, the PTC heater has a negative characteristic region and a positive characteristic region. The "negative characteristic region" is a region where electrical resistance decreases in proportion to temperature. The "positive characteristic region" is a region where electrical resistance increases in proportion to temperature.

[0084] When a current flows through a PTC heater in the negative characteristic region, the temperature of the PTC heater rises. As the temperature of the PTC heater rises, its electrical resistance decreases, causing the current to increase. In the negative characteristic region, the PTC heater repeats a cycle of temperature increase, electrical resistance decrease, and current increase. As the temperature rises, the PTC heater transitions from the negative characteristic region to the positive characteristic region.

[0085] As shown in FIG. 8, in the negative characteristic region, when comparing the electrical resistance R1 at temperature T1 with the electrical resistance R2 at temperature T2 higher than temperature T1, the electrical resistance R1 is greater than the electrical resistance R2.

[0086] 9A and 9B are schematic diagrams illustrating the heater current flowing through the PTC heater in the negative characteristic region. Fig. 9A shows the current Ion1 that flows when the PTC heater is turned on at temperature T1 shown in Fig. 8, and Fig. 9B shows the current Ion2 that flows when the PTC heater is turned on at temperature T2 shown in Fig. 8. In Fig. 9A and Fig. 9B, the currents Ion1 and Ion2 represent the currents at the start of current flow.

[0087] 9A and 9B, the current Ion1 is smaller than the current Ion2. Thus, when the PTC heater is switched on in the negative characteristic region, the lower the temperature, the smaller the current flowing through the PTC heater. That is, when the PTC heater is switched on in the negative characteristic region, the lower the temperature, the smaller the current at the start of power supply.

[0088] In the positive characteristic region, as opposed to the negative characteristic region, as the temperature of a PTC heater rises, the electrical resistance of the PTC heater increases. As the electrical resistance of the PTC heater increases, the current decreases, causing the temperature of the PTC heater to decrease. As the temperature of the PTC heater decreases, the electrical resistance decreases, causing the current to increase. As the current increases, the temperature of the PTC heater rises. In the positive characteristic region, a PTC heater stabilizes by repeating the cycle of temperature increase, electrical resistance increase, current decrease, temperature decrease, electrical resistance decrease, current increase, and temperature increase.

[0089] In this embodiment, the first heater 58 and the second heater 60, which are PTC heaters, are configured to be cooled by the wind generated by the first fan 62. Therefore, the temperature of the first heater 58 and the second heater 60 can be adjusted by adjusting the fan speed of the first fan 62. For example, as shown in FIG. 8 , when the control unit 90 sets the fan speed of the first fan 62 to Vf1, the temperature of the first heater 58 and the second heater 60 becomes Tf1 and the electrical resistance becomes Rf1. When the control unit 90 sets the fan speed of the first fan 62 to Vf2, which is lower than Vf1, the temperature of the first heater 58 and the second heater 60 rises to Tf2, which is higher than Tf1, and the electrical resistance is adjusted to Rf2, which is higher than Rf1. In this way, the temperature of the heater and the electrical resistance can be adjusted by adjusting the fan speed of the first fan 62.

[0090] FIG. 10 is a schematic diagram illustrating the heater current flowing through the PTC heater in the positive characteristic region. FIG. 10(a) shows the change in fan speed of the first fan 62. FIG. 10(b) shows the change in heater temperature of the first heater 58, which is a PTC heater. FIG. 10(c) shows the change in electrical resistance of the first heater 58. FIG. 10(d) shows the change in heater current of the first heater 58.

[0091] As shown in Fig. 10(a), in the positive characteristic region, when the fan speed of the first fan 62 is reduced from Vf1 to Vf2, the temperature of the first heater 58 increases from Tf1 to Tf2, as shown in Fig. 10(b). As a result, the electrical resistance of the first heater 58 increases from Rf1 to Rf2, as shown in Fig. 10(c), and the current of the first heater 58 decreases from Ih1 to Ih2, as shown in Fig. 10(d). In this way, in the positive characteristic region, the higher the temperature of the first heater 58 (PTC heater), the smaller the current. By adjusting the fan speed of the first fan 62, the magnitude of the current flowing through the first heater 58 (PTC heater) can be adjusted.

[0092] Next, the control of turning on and off the first heater 58 and the second heater 60 in this embodiment will be described.

[0093] Figure 11 is a schematic diagram illustrating relay control, fan speed control, heater current, and heater temperature. Figure 11(a) shows the relay control from turning on to turning off the first heater 58 and the second heater 60. Figure 11(b) shows the fan speed control of the first fan 62. Figure 11(c) shows the change in heater current. Figure 11(d) shows the heater temperature.

[0094] As shown in FIG. 11 , before the first heater 58 and the second heater 60 are switched on, the first heater 58 and the second heater 60 are cooled for a predetermined cooling period t10. The predetermined cooling period t10 is, for example, 10 seconds or more and 30 seconds or less. Specifically, the control unit 90 increases the fan speed of the first fan 62 to Vfc, thereby increasing the airflow rate of the first fan 62. This cools the first heater 58 and the second heater 60. Note that the fan speed Vfc is greater than the fan speed Vf2 but less than the fan speed Vf1.

[0095] The first heater 58 and the second heater 60 are switched on in the negative characteristic region. As described above, in the negative characteristic region, the higher the heater temperature, the lower the electrical resistance and the larger the heater current. Therefore, before the first heater 58 and the second heater 60 are switched on, the first fan 62 blows air to lower the initial temperatures of the first heater 58 and the second heater 60. This reduces the heater current generated when the first heater 58 and the second heater 60 are switched on, i.e., the current at the start of power supply.

[0096] After the first heater 58 and the second heater 60 have been cooled for a predetermined cooling period t10, the control unit 90 reduces the fan speed Vf of the first fan 62. The control unit 90 reduces the fan speed at the first timing tmg1 and the second timing tmg2 to be lower than the fan speed when both the first heater 58 and the second heater 60 are on. Specifically, the control unit 90 sets the fan speed Vf of the first fan 62 to a fan speed Vf2 that is lower than the fan speed Vf1 when both the first heater 58 and the second heater 60 are on. This promotes a temperature rise after the first heater 58 and the second heater 60 are turned on, enabling a smooth transition from the negative characteristic region to the positive characteristic region.

[0097] The control unit 90 also switches on the common relay 80. The common relay 80 is switched on before the first relay 82 and the second relay 84 are switched on.

[0098] Next, the control unit 90 switches on the first relay 82 at a first timing tmg1. When the first relay 82 is switched on, the first heater 58 is energized and switched on. At the first timing tmg1, an inrush current occurs in the first heater 58, causing the current to temporarily increase but decrease over time. At the first timing tmg1, the first heater 58 is in the negative characteristic region, and therefore, when a current flows through the first heater 58, the temperature rises. While the temperature is rising, the first heater 58 switches from the negative characteristic region to the positive characteristic region.

[0099] After switching on the first relay 82, the control unit 90 switches on the second relay 84 at a second timing tmg2. The second timing tmg2 is the timing when a first waiting time t20 has elapsed since the first timing tmg1. The first waiting time t20 is, for example, 15 seconds or more and 45 seconds or less. Preferably, the first waiting time t20 is 30 seconds. When the second relay 84 is switched on, the second heater 60 is energized and switched on. At the second timing tmg2, an inrush current occurs in the second heater 60, so the current temporarily increases but decreases over time. Furthermore, at the second timing tmg2, the second heater 60 is in the negative characteristic region, and therefore, when a current flows through the second heater 60, the temperature increases. While the temperature is increasing, the second heater 60 switches from the negative characteristic region to the positive characteristic region.

[0100] In this way, by shifting the first timing tmg1 at which the first relay 82 is switched on and the second timing tmg2 at which the second relay 84 is switched on, the timing at which the inrush current occurs can be dispersed compared to when the first heater 58 and the second heater 60 are switched on simultaneously. This reduces the overall peak value of the inrush current. As a result, it is possible to prevent the inrush current from exceeding the breaker capacity. Furthermore, if the compressor is configured to limit the current taking the inrush current into consideration, the impact on the compressor can be reduced.

[0101] After switching on the second relay 84, the control unit 90 increases the fan speed of the first fan. Specifically, after the second waiting time t21 has elapsed from the second timing tmg2, the control unit 90 sets the fan speed Vf of the first fan 62 to a fan speed Vf1 that is higher than the fan speed Vf2.

[0102] At this time, the first heater 58 and the second heater 60 are in the positive characteristic region. As described above, in the positive characteristic region, the higher the heater temperature, the greater the electrical resistance and the smaller the heater current. Therefore, by adjusting the fan speed of the first fan 62, the heater temperature can be adjusted, and the electrical resistance can be adjusted. This allows the heater current to be adjusted.

[0103] The control unit 90 reduces the fan speed Vf of the first fan 62 before switching off the common relay 80, the first relay 82, and the second relay 84. For example, the control unit 90 starts reducing the fan speed Vf of the first fan 62 a predetermined period t22 before the third timing tmg3 at which the common relay 80 is switched off. The control unit 90 also stops the first fan 62 a predetermined period t11 after the third timing tmg3. The predetermined period t22 is, for example, 10 seconds or more and 30 seconds or less. The predetermined period t11 is, for example, 0.1 seconds or more and 5 seconds or less. Because the third timing tmg3 is in the positive characteristic region, reducing the fan speed Vf of the first fan 62 increases the temperatures of the first heater 58 and the second heater 60, increasing their electrical resistance and reducing the heater current. As a result, stress on the common relay 80 can be reduced.

[0104] The control unit 90 switches off the common relay 80 after reducing the fan speed Vf of the first fan 62 and before switching off the first relay 82 and the second relay 84. For example, after switching off the common relay 80 at the third timing tmg3, the control unit 90 switches off the first relay 82 and the second relay 84 after a predetermined period t11 from the third timing tmg3. This switches off the first heater 58 and the second heater 60.

[0105] As described above, relays are susceptible to stress when they are turned on and off, causing current to flow and cut off. Therefore, by switching off the common relay 80, the first relay 82 and the second relay 84 can be switched off without current flowing through them. This reduces the stress (load) on the first relay 82 and the second relay 84.

[0106] According to this embodiment, it is possible to provide an air conditioner that can reduce the load on the components of the air conditioner.

[0107] Although the present invention has been described above with reference to the above-mentioned embodiments, the present disclosure is not limited to the above-mentioned embodiments.

[0108] For example, in the above embodiment, the control unit 90 controls both the first relay 82 and the second relay 84 to be on, but this is not limiting. The control unit 90 may alternately switch on the first relay 82 and the second relay 84.

[0109] FIG. 12 is a schematic diagram illustrating relay control in Modification 1. As shown in FIG. 12, while the first relay 82 is on, the second relay 84 is off, and while the second relay 84 is on, the first relay 82 is off. In other words, the first relay 82 and the second relay 84 are not on at the same time. This configuration allows the first heater 58 and the second heater 60 to be turned on alternately, enabling efficient heating. This shortens the on-time of each heater and reduces the load on the heater. As a result, the product life of the heater can be extended.

[0110] For example, in the above embodiment, an example has been described in which the air conditioner 10 controls the on / off of the first heater 58 and the second heater 60 using the common relay 80, the first relay 82, and the second relay 84, but the present invention is not limited to this. The air conditioner 10 may control the on / off of the first heater 58 and the second heater 60 using a configuration other than a relay. For example, the on / off of the first heater 58 and the second heater 60 may be controlled using semiconductor switches such as MOSFETs or IGBTs.

[0111] Furthermore, the common relay 80 is not an essential component of the air conditioner 10. Even if the air conditioner 10 does not have the common relay 80, by shifting the first timing tmg1 and the second timing tmg2, it is possible to prevent the inrush current from increasing in the first relay 82 and the second relay 84.

[0112] For example, in the above embodiment, the control unit 90 reduces the fan speed of the first fan 62 before switching off the first heater 58 and the second heater 60. However, the present invention is not limited to this. For example, the control unit 90 may reduce the fan speed of the first fan 62 before switching off at least one of the first heater 58 and the second heater 60.

[0113] For example, in the above embodiment, an example was described in which the air conditioner 10 was equipped with two heaters 58, 60, but the present invention is not limited to this. The air conditioner may be equipped with two or more heaters.

[0114] For example, in the above-described embodiment, the first heater 58 and the second heater 60 are PTC heaters, but this is not limiting. The first heater 58 and the second heater 60 do not have to be PTC heaters. For example, the first heater 58 and the second heater 60 may be heaters that use nichrome wire, carbon fiber, or the like.

[0115] In the present embodiment, the control unit 90 reduces the fan speed of the first fan 62 before switching off the first heater 58 and the second heater 60, thereby increasing the temperature of the first heater 58 and the second heater 60, increasing the electrical resistance, and reducing the heater current. However, the control unit 90 does not have to reduce the fan speed of the first fan 62. For example, the air conditioner 10 may increase the temperature of the first heater 58 and the second heater 60, increasing the electrical resistance, and reducing the heater current before switching off the first heater 58 and the second heater 60, without adjusting the fan speed of the first fan 62. In any configuration, the air conditioner 10 may reduce the heater current before switching off the first heater 58 and the second heater 60. For example, the control unit 90 may adjust the applied voltage to reduce the heater current. In the positive characteristic region, the current value decreases as the applied voltage increases, and increases as the applied voltage decreases. In the negative characteristic region, the current value increases as the applied voltage increases, and decreases as the applied voltage decreases. Alternatively, an auxiliary heater for adjusting the temperature of the PTC heater may be disposed near the heaters 58 and 60. The control unit 90 may control the auxiliary heater to adjust the temperature of the heaters 58 and 60, thereby adjusting the resistance and the current.

[0116] For example, in the above-described embodiment, the control unit 90 switches on the first relay 82 and then switches on the second relay 84 at the second timing tmg2 after the first waiting time t20 has elapsed. However, this is not limiting. The control unit 90 may distribute the switching on of the first relay 82 and the second relay 84. For example, if the air conditioner 10 has a detection unit that detects the heater current, the control unit 90 may determine the timing of switching on the first relay 82 and the second relay 84 based on the heater current detected by the detection. Even with this configuration, the timing of the occurrence of inrush currents in the first heater 58 and the second heater 60 can be shifted. This reduces the stress (load) on the heaters and relays that constitute the air conditioner 10.

[0117] It should be noted that, in this specification, terms such as "first," "second," etc. are used for descriptive purposes only and should not be understood as expressing or implying the relative importance or ranking of technical features. Features qualified as "first" and "second" expressly or imply the inclusion of one or more of such features.

[0118] In other words, the air conditioner according to the embodiment of the present disclosure is, in a broad sense, an air conditioner comprising an indoor unit and an outdoor unit, and comprising: an absorbent material provided in the outdoor unit that absorbs moisture from the outdoor air; a flow path through which the outdoor air flows that passes through the absorbent material and connects the outdoors with the inside of the indoor unit; a first heater and a second heater that heat the outdoor air upstream of the absorbent material in the flow path; and a control unit that controls the on / off of the first heater and the second heater, wherein the control unit differentiates between a first timing for switching on the first heater and a second timing for switching on the second heater. [Industrial Applicability]

[0119] The present disclosure is applicable to any air conditioner that includes an indoor unit and an outdoor unit. [Explanation of symbols]

[0120] 10 Air conditioner 20 Indoor unit 30 Outdoor unit 40 Four-way valve 50 Ventilation Equipment 52 Absorbent material 54 Motor 56 Ventilation duct 58 First heater 60 Second heater 62 Fan (First Fan) 64 Damper device 66 Fan (Second Fan) 70 Remote Controller 80 Common Relay 82 First Relay 84 Second Relay 90 Control Unit P1 flow path (first flow path) P2 flow path (second flow path)

Claims

1. An air conditioner comprising an indoor unit and an outdoor unit, an absorbent material provided in the outdoor unit that absorbs moisture in the outdoor air; a flow path through which outdoor air flows, the flow path passing through the absorbent material, connecting the outside of the room with the inside of the indoor unit; a first heater and a second heater that heat the outdoor air upstream of the absorbent material in the flow path; a fan that generates a flow of outdoor air in the flow path toward the indoor unit; a control unit that controls on / off of the first heater and the second heater and controls the fan; Equipped with the first heater and the second heater are each a PTC (Positive Temperature Coefficient) heater; The control unit a first timing for switching on the first heater and a second timing for switching on the second heater are made different from each other; reducing the fan speed of the fan before the first timing and the second timing; Air conditioner.

2. a first relay for switching on and off the first heater; a second relay for switching the second heater on and off; Further provided with the control unit controls a switching timing for switching on and off the first relay and the second relay, and shifts the first timing from the second timing; The air conditioner according to claim 1.

3. the second timing is a timing when a first waiting time has elapsed since the first timing; The air conditioner according to claim 2.

4. the first waiting time is equal to or greater than 15 seconds and equal to or less than 45 seconds; The air conditioner according to claim 3.

5. a common relay that controls a current flowing through the first relay and the second relay; the control unit switches the common relay on and off before switching the first relay and the second relay on and off. The air conditioner according to any one of claims 2 to 4.

6. the control unit controls the fan to cool the first heater and the second heater by blowing air from the fan before turning on the first heater and the second heater. The air conditioner according to any one of claims 1 to 5.

7. the control unit increases the fan speed of the fan after a second waiting time has elapsed from the second timing. The air conditioner according to any one of claims 1 to 6.

8. the second waiting time is equal to or greater than 15 seconds and equal to or less than 45 seconds; The air conditioner according to claim 7.

9. the control unit reduces the fan speed of the fan before switching off at least one of the first heater and the second heater. The air conditioner according to any one of claims 1 to 8.

10. the control unit alternately switches on the first relay and the second relay; The air conditioner according to claim 2.

Images