JP6141508B2 - Air conditioner and control method of air conditioner - Google Patents

Description

  The present invention relates to an air conditioner having a dehumidifying function and a method for controlling the air conditioner having a dehumidifying function.

  As a conventional air conditioner, for example, there is an apparatus including a refrigerant circulation circuit in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected by piping, and a defrost heater. In the refrigerant circulation circuit, the refrigerant compressed by the compressor becomes a high-temperature and high-pressure gas refrigerant and is sent to the condenser. The refrigerant flowing into the condenser is liquefied by releasing heat into the air. The liquefied refrigerant is decompressed by the expansion valve, becomes a gas-liquid two-phase refrigerant, and flows into the evaporator. The gas-liquid two-phase refrigerant is gasified by absorbing heat from ambient air with an evaporator, and is sucked into the compressor.

  When such an air conditioner is used in, for example, a freezer warehouse, a refrigerated warehouse, etc., in order to maintain the internal temperature in a temperature range lower than 10 ° C., the evaporator of the air conditioner It is necessary to control the evaporating temperature to be lower than 0 ° C., and as a result, frosting occurs in the evaporator, and the refrigerating capacity (dehumidifying capacity) of the air conditioner decreases. Therefore, the defrosting operation is periodically performed by the defrost heater attached to the evaporator.

  And in such an air conditioning apparatus, energy will be consumed extra by the part which the defrosting operation is performed, and the operating efficiency of an air conditioning apparatus will fall. Further, during the defrosting operation, the load on the air conditioner after the defrosting operation is increased due to the rise in the internal temperature, and as a result, the power consumption of the air conditioner is reduced. To increase.

  In addition, when such an air conditioner uses, for example, a compressor whose rotation speed is controlled, along with a decrease in cooling load in the middle period of cooling (rainy season, autumn, etc.), The rotational speed of the compressor is lowered to follow the load. At that time, the evaporation temperature in the evaporator rises and the sensible heat of the room is removed, but the latent heat of the room etc. is not removed, resulting in an increase in the relative humidity of the room and the air-conditioned space. People who are in the area feel uncomfortable.

  Therefore, in the conventional air conditioner, the moisture in the air flowing into the evaporator (heat absorber) is combined with the refrigeration cycle and the moisture adsorbing means, and the moisture adsorbing means removes in advance, For example, the defrosting operation is not necessary, and the discomfort of the person in the air-conditioned space is reduced.

  For example, Patent Literature 1 discloses an air conditioner including a desiccant rotor that is a moisture adsorption unit. In the air conditioner disclosed in Patent Document 1, air from which moisture has been removed by a desiccant rotor is supplied to an evaporator (heat absorber). In addition, in order to regenerate the desiccant rotor by desorbing moisture from the desiccant rotor that has adsorbed moisture, air heated by a condenser (heat radiator) is supplied to the desiccant rotor.

JP 2001-241893 A (paragraph [0055] to paragraph [0090], FIGS. 2 to 4)

  For example, in the air conditioner disclosed in Patent Document 1, a moisture absorption air passage and a moisture release air passage are necessary, and in order to suppress air leakage between the air passages, a moisture absorption air passage is required. A seal structure is required that hermetically separates the boundary between the air passage and the air passage for moisture release. Therefore, an air conditioning apparatus will enlarge and cost will be increased. Moreover, since the air path for moisture absorption and the air path for moisture release are required, the air path structure in an air conditioning apparatus is complicated, and replacement | exchange of a desiccant rotor etc. will become difficult.

  The present invention has been made against the background of the above problems, and it is intended to obtain an air conditioner having improved cost performance and maintenance performance while improving dehumidification performance, particularly dehumidification performance in a low temperature environment. It is aimed. Moreover, it aims at obtaining the control method of such an air conditioning apparatus.

  The air conditioner according to the present invention includes a refrigerant circulation circuit in which a compressor, a flow path switching device, a first heat exchanger, a decompression device, and a second heat exchanger are sequentially connected by piping, and the first heat A desiccant material disposed between the exchanger and the second heat exchanger, and a blower that generates an airflow that passes through the first heat exchanger, the desiccant material, and the second heat exchanger in this order. And a temperature detecting means for detecting the temperature of the airflow; and the flow path switching device is controlled so that the first heat exchanger acts as a condenser or a radiator, and the second heat exchanger is an evaporator. The first operation mode for desorbing moisture held in the desiccant material, the first heat exchanger as an evaporator, and the second heat exchanger as a condenser or radiator And let the desiccant material adsorb moisture. A control device that switches between operation modes, wherein the control device determines whether the temperature of the airflow detected by the temperature detection means is low or high, and the temperature determination means When it is determined that the temperature of the airflow is low, the surface temperature of the first heat exchanger is higher than the surface temperature of the first heat exchanger in the second operation mode, and the desiccant material And a third operation mode setting means for shifting to the third operation mode for adsorbing moisture.

  In the air conditioner according to the present invention, the first heat exchanger, the desiccant material, and the second heat exchanger are arranged in series in the air passage, and the first heat exchanger is the condenser or In addition to acting as a radiator, the second heat exchanger acts as an evaporator to desorb moisture held in the desiccant material, the first heat exchanger acts as an evaporator, Dehumidification of the conditioned space is performed by switching the second operation mode in which the two heat exchangers act as a condenser or a radiator to adsorb moisture to the desiccant material. Therefore, the desiccant material adsorbing action is combined with the cooling action and heating action in the refrigerant circulation circuit to increase the amount of dehumidification, thereby improving the dehumidifying performance and relatively difficult to dehumidify. High dehumidifying performance is ensured even in a low temperature environment.

  Further, in the air conditioner according to the present invention, a common air path is used in the first operation mode for desorbing moisture held in the desiccant material and in the second operation mode for adsorbing moisture to the desiccant material. The increase in the size of the air conditioner is suppressed, and the dehumidifying performance is improved, and the cost performance is improved. Further, the complexity of the air path structure in the air conditioner is suppressed, and the dehumidifying performance is improved, and the maintenance performance is improved.

  Further, in the air conditioner according to the present invention, when the temperature determination unit determines that the temperature of the airflow is low, the third operation mode setting unit determines that the surface temperature of the first heat exchanger is in the second operation mode. A transition is made to the third operation mode in which moisture is adsorbed by the desiccant material in a state higher than the surface temperature of the first heat exchanger. Therefore, when the second operation mode is performed in a state where the temperature of the air sucked into the air conditioner is low, frost formation on the first heat exchanger is suppressed, and the cooling operation of the refrigeration cycle is suppressed. The amount of dehumidification in the dehumidification performed by is ensured over a long period of time, and the operating efficiency of the refrigeration cycle is improved.

  That is, the air conditioner according to the present invention performs dehumidification by the desiccant material and the first heat exchanger disposed on the upstream side in the second operation mode in which moisture is adsorbed to the desiccant material. Therefore, if the temperature determination means determines that the temperature of the airflow is low, the surface temperature of the first heat exchanger is the first in the second operation mode. This is realized while utilizing existing equipment by the third operation mode setting means for causing the desiccant material to adsorb moisture and shifting to the third operation mode in a state higher than the surface temperature of the heat exchanger.

It is a figure for demonstrating the structure of the air conditioning apparatus which concerns on Embodiment 1. FIG. FIG. 3 is a moist air diagram in the first operation mode of the air-conditioning apparatus according to Embodiment 1. It is a moist air diagram in the 2nd operation mode of the air harmony device concerning Embodiment 1. It is a figure for demonstrating the adsorption characteristic of the desiccant material of the air conditioning apparatus which concerns on Embodiment 1. FIG.

Hereinafter, an air conditioner according to the present invention will be described with reference to the drawings.
In addition, the structure, operation | movement, etc. which are demonstrated below are only examples, and the air conditioning apparatus which concerns on this invention is not limited to the case where it is such a structure, operation | movement, etc. Moreover, in each figure, the same code | symbol is attached | subjected to the same or similar thing, or attaching | subjecting code | symbol is abbreviate | omitted. Further, the illustration of the fine structure is simplified or omitted as appropriate. In addition, overlapping or similar descriptions are appropriately simplified or omitted.

Embodiment 1 FIG.
The air conditioning apparatus according to Embodiment 1 will be described.
<Configuration of air conditioner>
Below, the structure of the air conditioning apparatus which concerns on Embodiment 1 is demonstrated.
1 is a diagram for explaining a configuration of an air-conditioning apparatus according to Embodiment 1. FIG. In FIG. 1, the air flow is indicated by a white arrow, the refrigerant flow in the first operation mode is indicated by a solid arrow, and the refrigerant flow in the second operation mode is indicated by a dotted arrow. Further, the flow path of the four-way valve 12 in the first operation mode is indicated by a solid line, and the flow path of the four-way valve 12 in the second operation mode is indicated by a dotted line.

  As shown in FIG. 1, an air conditioner 100 includes a compressor 11, a four-way valve 12 that is a flow path switching device, a first heat exchanger 13, and an expansion valve that is a decompression device in a housing 1. 14 and a second heat exchanger 15 disposed substantially parallel to the first heat exchanger 13, and these are connected by a pipe to form the refrigerant circulation circuit A. The inside of the housing 1 is partitioned into an air passage chamber 2 and a machine chamber 3 by a drain pan 21 disposed below the first heat exchanger 13 and the second heat exchanger 15. The compressor 11 and the four-way valve 12 are arranged in the machine room 3, and the others are arranged in the air passage chamber 2.

  By switching the flow path of the four-way valve 12, the refrigerant circulation direction in the refrigerant circuit A is reversed. The four-way valve 12 may be another flow path switching device. When the flow path of the four-way valve 12 is switched to the flow path indicated by the solid line in FIG. 1, the refrigerant discharged from the compressor 11 is transferred to the four-way valve 12, the first heat exchanger 13, the expansion valve 14, and the second heat. It flows in the order of the exchanger 15 and the four-way valve 12, and returns to the compressor 11. In that case, the 1st heat exchanger 13 acts as a condenser, and the 2nd heat exchanger 15 acts as an evaporator. When the flow path of the four-way valve 12 is switched to the flow path indicated by the dotted line in FIG. 1, the refrigerant discharged from the compressor 11 is transferred to the four-way valve 12, the second heat exchanger 15, the expansion valve 14, and the first heat. It flows in the order of the exchanger 13 and the four-way valve 12 and returns to the compressor 11. In that case, the 2nd heat exchanger 15 acts as a condenser, and the 1st heat exchanger 13 acts as an evaporator.

The refrigerant of the refrigerant circuit A includes, for example, R410A refrigerant. The refrigerant in the refrigerant circuit A is not limited to such a refrigerant, and may include, for example, an HFC refrigerant, an HC refrigerant, an HFO refrigerant, or a natural refrigerant. That is, for example, a mixture of HFO refrigerant and HFC refrigerant may be used. The natural refrigerant includes, for example, a CO ₂ refrigerant or an NH ₃ refrigerant. For example, when the high pressure side pressure of the refrigerant circuit A is equal to or higher than the critical pressure, such as when the natural refrigerant is a CO ₂ refrigerant, the first heat exchanger 13 or the second heat exchanger 15 dissipates heat. Acts as a vessel.

  The first heat exchanger 13 and the second heat exchanger 15 are plate fin tube type heat exchangers. In the first heat exchanger 13 and the second heat exchanger 15, heat is exchanged between the refrigerant flowing in the heat transfer tubes and the air flowing around the fins.

  The expansion valve 14 decompresses and expands the refrigerant passing therethrough. The expansion valve 14 is a valve whose opening degree is fixed. The expansion valve 14 is not limited to such a valve, and may be, for example, an electronic expansion valve capable of opening degree control. The expansion valve 14 may be another decompression device such as a capillary tube.

  The air passage chamber 2 is formed with a suction port 4 for introducing air to be air-conditioned into the air passage chamber 2, an air outlet 5 for discharging the air-conditioned air to the outside of the air conditioner 100, and an inspection window 6. Is done. An air passage forming plate 22 is disposed in the air passage chamber 2 to form an air passage B that communicates between the suction port 4 and the air outlet 5. A lid 7 that closes the inspection window 6 is attached to the inspection window 6. At the time of inspection, the lid 7 is removed.

  In the air passage B, a first heat exchanger 13, a desiccant block 23, which is a desiccant material, disposed substantially parallel to the first heat exchanger 13, and a first heat exchanger disposed substantially parallel to the desiccant block 23. The two heat exchangers 15 and the fan 24, which is a blower, are arranged substantially in series. The fan 24 may be disposed in the downstream portion of the air passage B, or may be disposed in the upstream portion of the air passage B. When the fan 24 is driven, an air flow indicated by a white arrow in FIG. That is, the air drawn into the air passage B from the suction port 4 passes through the first heat exchanger 13, the desiccant block 23, the second heat exchanger 15, and the fan 24 in this order, and is then discharged from the blowout port 5. The

  The desiccant block 23 is a desiccant material, which is a material that absorbs and desorbs moisture, and is solidified and molded into a rectangle. The desiccant material is, for example, zeolite, silica gel, mesoporous silica, a polymeric adsorbent, or the like.

  In addition, the 1st heat exchanger 13, the desiccant block 23, and the 2nd heat exchanger 15 do not necessarily need to be arrange | positioned in parallel. Moreover, the 1st heat exchanger 13, the desiccant block 23, and the 2nd heat exchanger 15 do not necessarily need to be arrange | positioned in parallel with a gravitational direction.

  The air passage chamber 2 is provided with a temperature / humidity sensor 81 that measures the temperature and humidity of the air sucked into the air conditioner 100, that is, the temperature and humidity of the air around the air conditioner 100. The machine room 3 is provided with a control device 90 that controls the operation of the entire air conditioner 100. The control device 90 controls the dehumidifying operation described later (switching of the operation mode according to the detection signal of the temperature / humidity sensor 81, etc.), controls the rotation speed of the compressor 11, controls the opening of the expansion valve 14, Controls the number of rotations. The control device 90 includes at least a temperature determination unit 91 and a third operation mode setting unit 92. The temperature determination unit 91 and the third operation mode setting unit 92 control the dehumidification operation (temperature This is used for switching the operation mode according to the detection signal of the humidity sensor 81). All or each part constituting the control device 90 may be constituted by, for example, a microcomputer, a microprocessor unit or the like, or may be constituted by an updatable one such as firmware, or by a command from the CPU or the like. It may be a program module to be executed. Further, the control device 90 may be provided outside the air conditioner 100. The temperature / humidity sensor 81 corresponds to “temperature detection means” in the present invention. The temperature determination unit 91 corresponds to “temperature determination means” in the present invention. The third operation mode setting unit 92 corresponds to “third operation mode setting means” in the present invention.

  Note that the temperature / humidity sensor 81 may detect the temperature / humidity of the air sucked into the air conditioner 100, or detect other physical quantities that can be converted into the temperature / humidity of the air sucked into the air conditioner 100. May be. That is, the “temperature detection means” in the present invention may be any means that substantially detects the temperature. Further, “when it is determined that the temperature of the airflow is low” in the present invention may be a case where it is determined that the temperature of the airflow is substantially low.

<Dehumidifying operation of air conditioner>
Hereinafter, the dehumidifying operation of the air-conditioning apparatus according to Embodiment 1 will be described.
In the air conditioner 100, in the dehumidifying operation, the control device 90 switches the flow path of the four-way valve 12, whereby the two operation modes of the first operation mode and the second operation mode are performed.
First, each operation in the first operation mode and the second operation mode will be described.

(Refrigeration cycle operation in the first operation mode)
In the first operation mode, the flow path of the four-way valve 12 is switched as shown by the solid line in FIG. The low-pressure gas refrigerant sucked into the compressor 11 is compressed into a high-temperature and high-pressure gas refrigerant. The refrigerant discharged from the compressor 11 flows into the first heat exchanger 13 through the four-way valve 12. The refrigerant flowing into the first heat exchanger 13 dissipates heat to the air flowing through the air passage B to heat the air, and is cooled and condensed by the air to become a high-pressure liquid refrigerant. 13 will flow out. The liquid refrigerant flowing out of the first heat exchanger 13 is decompressed by the expansion valve 14 and becomes a low-pressure two-phase refrigerant. The refrigerant that has become a low-pressure two-phase refrigerant flows into the second heat exchanger 15, absorbs heat from the air flowing through the air passage B, cools the air, is heated by the air and evaporates, and low-pressure gas It becomes a refrigerant and flows out from the second heat exchanger 15. The gas refrigerant flowing out of the second heat exchanger 15 is sucked into the compressor 11 through the four-way valve 12.

(Air operation in the first operation mode)
FIG. 2 is a wet air diagram in the first operation mode of the air-conditioning apparatus according to Embodiment 1. In FIG. 2, the vertical axis represents the absolute humidity of the air, and the horizontal axis represents the dry bulb temperature of the air. Further, in FIG. 2, a state where the air is saturated air is indicated by a curve C. That is, on the curve C, the relative humidity is 100%.

  If the air around the air conditioner 100 is in the state of point a shown in FIG. 2, the air flows into the air passage B and is then heated by the first heat exchanger 13, so that the temperature Rises to the point b shown in FIG. 2, the relative humidity decreases, and flows into the desiccant block 23. At that time, since the relative humidity of the air is low, the moisture held in the desiccant block 23 is desorbed (released), and the amount of moisture contained in the air increases. Further, desorption heat associated with desorption is deprived from the air flowing into the desiccant block 23, and the temperature of the air decreases. Therefore, the air flowing out from the desiccant block 23 is in the state of point c shown in FIG. The air flowing out from the desiccant block 23 then flows into the second heat exchanger 15 and is cooled. At that time, since the refrigerant circuit A is controlled by the control device 90 so that the refrigerant temperature in the second heat exchanger 15 becomes lower than the dew point temperature of the air, The air is cooled and dehumidified by the heat exchanger 15, and is in the state of point d shown in FIG. 2 to become air having a low temperature and a low absolute humidity. The air that has flowed out of the second heat exchanger 15 flows into the fan 24 and is discharged from the air outlet 5 to the outside of the air conditioner 100.

(Operation of the refrigeration cycle in the second operation mode)
In the second operation mode, the flow path of the four-way valve 12 is switched as indicated by a dotted line in FIG. The low-pressure gas refrigerant sucked into the compressor 11 is compressed into a high-temperature and high-pressure gas refrigerant. The refrigerant discharged from the compressor 11 flows into the second heat exchanger 15 through the four-way valve 12. The refrigerant flowing into the second heat exchanger 15 radiates heat to the air flowing through the air passage B to heat the air, and is cooled and condensed by the air to become a high-pressure liquid refrigerant. Flows out of 15. The liquid refrigerant flowing out of the second heat exchanger 15 is decompressed by the expansion valve 14 and becomes a low-pressure two-phase refrigerant. The refrigerant that has become a low-pressure two-phase refrigerant flows into the first heat exchanger 13, absorbs heat from the air flowing through the air passage B, cools the air, and is heated and evaporated by the air to generate a low-pressure gas. It becomes a refrigerant and flows out from the first heat exchanger 13. The gas refrigerant flowing out of the first heat exchanger 13 is sucked into the compressor 11 through the four-way valve 12.

(Air operation in the second operation mode)
FIG. 3 is a moist air diagram in the second operation mode of the air-conditioning apparatus according to Embodiment 1. In FIG. 3, the vertical axis represents the absolute humidity of the air, and the horizontal axis represents the dry bulb temperature of the air. In FIG. 3, a state where the air is saturated air is indicated by a curve C. That is, on the curve C, the relative humidity is 100%.

  Assuming that the air around the air conditioner 100 is in the state of point a shown in FIG. 3, the air flows into the air passage B and is then cooled by the first heat exchanger 13. At that time, the refrigerant circulation circuit A is controlled by the control device 90 so that the refrigerant temperature in the first heat exchanger 13 is lower than the dew point temperature of the air. The air is cooled and dehumidified by the heat exchanger 13, and is in a state of point e shown in FIG. 3 to become air having a low temperature and a high relative humidity. The air that has flowed out of the first heat exchanger 13 flows into the desiccant block 23. At that time, since the relative humidity of the air is high, moisture is adsorbed to the desiccant block 23, and the amount of moisture contained in the air is reduced, so that the air is further dehumidified. Further, the air flowing into the desiccant block 23 is heated by the adsorption heat accompanying the adsorption, and the temperature of the air rises. Therefore, the air flowing out from the desiccant block 23 is in the state of point f shown in FIG. 3, and becomes high temperature and low humidity. The air that has flowed out of the desiccant block 23 is then heated by the second heat exchanger 15 to reach the point g shown in FIG. The air that has flowed out of the second heat exchanger 15 flows into the fan 24 and is discharged from the air outlet 5 to the outside of the air conditioner 100.

  As described above, in the second operation mode, the desiccant is performed in the dehumidification (the difference between the absolute humidity at point a and the absolute humidity at point e in FIG. 3) performed by cooling using the refrigerant in the first heat exchanger 13. Dehumidification performed by the adsorption action of the block 23 (the difference between the absolute humidity at point e and the absolute humidity at point f in FIG. 3) is added. That is, as is apparent from a comparison between FIG. 2 and FIG. 3, it is possible to ensure a larger amount of dehumidification in the second operation mode than in the first operation mode. Therefore, the dehumidifying function of the air conditioner 100 is mainly realized by the second operation mode.

  And the air conditioning apparatus 100 repeats a 1st operation mode and a 2nd operation mode alternately. For example, when the second operation mode is continuously carried out, there is an upper limit on the amount of moisture that can be held by the desiccant block 23. Therefore, after a certain period of time, moisture is not adsorbed by the desiccant block 23, and dehumidification is performed. The amount is reduced. Therefore, the air conditioner 100 switches to the first operation mode when the amount of moisture held in the desiccant block 23 is close to the upper limit, and performs an operation of desorbing moisture from the desiccant block 23. As described above, by alternately performing the first operation mode and the second operation mode, the adsorption / desorption action of the desiccant block 23 is sequentially exhibited, and the dehumidification amount is increased by the adsorption action of the desiccant block 23. This effect is sustained over a long period of time.

(Timing for switching between the first operation mode and the second operation mode)
Next, the timing of switching between the first operation mode and the second operation mode will be described.
Each operation time in the first operation mode and the second operation mode may be set to an appropriate time according to the air condition, the operation state of the air conditioner 100, and the like. Each operation time in the first operation mode and the second operation mode may be a predetermined time set in advance.

  An appropriate operation time in the first operation mode is a time required until an appropriate amount of moisture is desorbed from the desiccant block 23 and an amount of moisture remaining in the desiccant block 23 becomes an appropriate amount. When the first operation mode is switched to the second operation mode in a state where the amount of moisture remaining in the desiccant block 23 is larger than the appropriate amount, the amount of moisture adsorbed on the desiccant block 23 in the second operation mode is reduced. As a result, the amount of dehumidification in the second operation mode is reduced. Conversely, if the operation time of the first operation mode is too long, switching to the second operation mode with a large amount of dehumidification compared to the first operation mode is delayed, and in the second half of the operation time of the first operation mode, Since the state in which the desiccant block 23 is hardly able to desorb moisture is continued, when the switching between the first operation mode and the second operation mode is repeated, the dehumidification amount is significantly reduced.

  An appropriate operation time in the second operation mode is a time during which an appropriate amount of moisture is adsorbed on the desiccant block 23 and the amount of moisture held in the desiccant block 23 becomes an appropriate amount. When the second operation mode is switched to the first operation mode in a state where there is room to be adsorbed by the desiccant block 23, the operation time of the second operation mode with a large amount of dehumidification is shortened compared to the first operation mode. When the switching between the first operation mode and the second operation mode is repeated, the dehumidification amount decreases significantly. On the other hand, if the operation time in the second operation mode is too long, the desiccant block 23 will continue to be unable to adsorb moisture in the second half of the second operation mode, and the dehumidification amount will similarly decrease.

  Since the amount of moisture held by the desiccant block 23 varies depending on the relative humidity of the air flowing into the desiccant block 23, the proper operation time in the first operation mode and the proper operation time in the second operation mode are It changes depending on the relative humidity of the air flowing into the block 23. That is, when air having a high relative humidity flows into the desiccant block 23, the moisture held in the desiccant block 23 is difficult to be desorbed, and conversely, the amount of moisture adsorbed on the desiccant block 23 increases. In addition, when air having a low relative humidity flows into the desiccant block 23, the moisture held in the desiccant block 23 is easily desorbed, and conversely, the amount of moisture adsorbed on the desiccant block 23 is reduced.

  Therefore, in the air conditioning apparatus 100, the relative humidity of the intake air is obtained based on the detection signal of the temperature / humidity sensor 81, and the respective operation times of the first operation mode and the second operation mode are determined according to the relative humidity. To do.

  Specifically, the control device 90 generates relative humidity (hereinafter referred to as “reference relative humidity”) that serves as a reference for the intake air, and the intake air having the reference relative humidity that is obtained in advance through experiments, simulations, and the like. The reference operation time of each of the first operation mode and the second operation mode that can increase the dehumidification amount when passing through the path B is stored, and the actual relative humidity of the intake air and the reference relative humidity According to the magnitude relationship, the time obtained by appropriately increasing or decreasing the reference operation time is determined as the operation time of each of the first operation mode and the second operation mode.

  For example, the control device 90 obtains the actual relative humidity of the intake air based on the detection signal of the temperature / humidity sensor 81 at the start of the dehumidifying operation. If the relative humidity is higher than the pre-stored reference relative humidity, the amount of moisture desorbed from the desiccant block 23 in the first operation mode is equal to the relative relative humidity of the actual intake air. Since it is smaller than the amount of moisture to be desorbed when it is equal to the humidity, the operation time of the first operation mode is set to a longer time than the preset reference operation time of the first operation mode. In the second operation mode, the amount of moisture adsorbed on the desiccant block 23 is larger than the amount of moisture adsorbed when the actual relative humidity of the intake air is equal to the reference relative humidity. The operation time in the second operation mode is set to a time shorter than the preset reference operation time in the second operation mode.

  Further, for example, when the relative humidity is lower than the reference relative humidity stored in advance, the amount of moisture desorbed from the desiccant block 23 in the first operation mode is the actual relative humidity of the intake air. Since the amount of moisture to be desorbed in the case of being equal to the reference relative humidity is increased, the operation time of the first operation mode is set to a short time compared to the preset reference operation time of the first operation mode. To do. In the second operation mode, the amount of moisture adsorbed on the desiccant block 23 is smaller than the amount of moisture adsorbed when the actual relative humidity of the intake air is equal to the reference relative humidity. The operation time in the second operation mode is set to a longer time than the preset reference operation time in the second operation mode.

Further, in the air conditioner 100, the temperature determination unit 91 of the control device 90 is based on the detection signal of the temperature / humidity sensor 81 when switching to the second operation mode or when executing the second operation mode. It is determined whether or not the temperature of the intake air is equal to or lower than a preset reference temperature. Then, when the temperature determination unit 91 of the control device 90 determines that the temperature of the intake air is equal to or lower than a preset reference temperature, immediately after that or after the set standby time has elapsed, The three operation mode setting unit 92 shifts the defrosting operation to the third operation mode. The third operation mode is an operation mode in which moisture is adsorbed to the desiccant block 23 in a state where the surface temperature of the first heat exchanger 13 is higher than the surface temperature of the first heat exchanger 13 in the second operation mode. It is. The standby time is the time until clogging due to frosting occurs in the first heat exchanger 13, which is stored or calculated in the third operation mode setting unit 92. The waiting time may be set to a different time according to the temperature of the intake air. That is, the standby time may be set to a shorter time as the temperature of the intake air is lower. When the third operation mode is continued and an appropriate amount of moisture is adsorbed to the desiccant block 23, the control device 90 switches the flow path of the four-way valve 12 and shifts to the first operation mode.
The operation in the third operation mode will be described below.

(Operation of the refrigeration cycle in the third operation mode)
In the third operation mode, in the second operation mode, the compressor 11 is stopped in a state where the flow path of the four-way valve 12 is switched to the flow path indicated by the dotted line in FIG. That is, in the third operation mode, the circulation of the refrigerant in the refrigerant circuit A is stopped, so that the first heat exchanger 13 does not function as an evaporator, and the surface temperature of the first heat exchanger 13 increases. In addition, the second heat exchanger 15 does not function as a condenser.

(Air operation in the third operation mode)
In the third operation mode, driving of the fan 24 in the second operation mode is continued. Therefore, the air around the air conditioner 100 passes through the first heat exchanger 13, then flows into the desiccant block 23, and moisture is adsorbed by the desiccant block 23 to be dehumidified. The air that has flowed out of the desiccant block 23 then passes through the second heat exchanger 15, flows into the fan 24, and is discharged from the air outlet 5 to the outside of the air conditioner 100.

<Desicant material>
FIG. 4 is a diagram for explaining adsorption characteristics of a desiccant material in the air-conditioning apparatus according to Embodiment 1. In FIG. 4, the vertical axis represents the equilibrium adsorption rate of moisture, and the horizontal axis represents the relative humidity of air. In FIG. 4, D represents the adsorption characteristic when the desiccant material is silica gel or zeolite. In FIG. 4, E represents the adsorption characteristic when the desiccant material is a porous silicon material and mesoporous silica having a large number of pores of about 1.5 nm. In FIG. 4, F represents the adsorption characteristic when the desiccant material is a polymer adsorbent.

  As shown in FIG. 4, the mesoporous silica has a slope in which the change rate of the equilibrium adsorption rate with respect to the relative humidity is less than 30% or 40% in the relative humidity range of about 30% to 40%. It is large compared to the slope in the exceeding range. In addition, the polymer adsorbent has a markedly high equilibrium adsorption rate in a range where the relative humidity is high. The desiccant material of the desiccant block 23 may be any of D, E, and F in the figure. When the desiccant material of the desiccant block 23 is E or F in the figure, it is necessary to lower the relative humidity during desorption compared to the case where the desiccant material of the desiccant block 23 is D in the figure When the first heat exchanger 13 acts as a condenser in the first operation mode, the desiccant block 23 can be desorbed using the air that has passed through the first heat exchanger 13. . In the case of D in the figure, an auxiliary heater (not shown) is required depending on the case.

<Operation of air conditioner>
Below, the effect | action of the air conditioning apparatus which concerns on Embodiment 1 is demonstrated.
In the air conditioner 100, the first operation mode and the second operation are performed in the state where the first heat exchanger 13, the desiccant block 23, and the second heat exchanger 15 are arranged in series in the air passage B. By switching between modes, the air-conditioned space is dehumidified. Therefore, by combining the adsorption action of the desiccant block 23 with the cooling action and the heating action in the refrigerant circuit A, the amount of dehumidification increases, the dehumidification performance is improved, and the dehumidification is relatively reduced. High dehumidification performance is ensured even in difficult low-temperature environments.

  In particular, in the second operation mode, dehumidification performed by the desiccant block 23 is added to dehumidification performed by the cooling action of the refrigeration cycle, that is, dehumidification performed by the first heat exchanger 13, and thus dehumidification performance is improved. Moreover, high dehumidification performance is ensured even in a low temperature environment where dehumidification is relatively difficult.

  In the second operation mode, if the dehumidification performed by the desiccant block 23 is not added to the dehumidification performed by the cooling action of the refrigeration cycle, that is, the dehumidification performed by the first heat exchanger 13, the air path B If the temperature of the air flowing through the air is about 10 ° C. or less, frost formation occurs in the first heat exchanger 13, so the frequency of defrosting operation increases, and the dehumidification capacity extremely decreases. On the other hand, when the dehumidification performed by the desiccant block 23 is added to the dehumidification performed by the cooling action of the refrigeration cycle, that is, the dehumidification performed by the first heat exchanger 13, the temperature of the air flowing through the air passage B is about Even if it is 10 degrees C or less, it becomes possible to suppress the dehumidification performed in the 1st heat exchanger 13 only by the dehumidification performed in the desiccant block 23, the frequency of a defrosting operation increases, and dehumidification capability is carried out. It is possible to avoid the extreme decrease.

  Further, when the dehumidification performed by the desiccant block 23 is not added to the dehumidification performed by the cooling action of the refrigeration cycle, that is, the dehumidification performed by the first heat exchanger 13, the air flowing through the air path B is It was difficult to make the relative humidity below about%. On the other hand, in the air conditioner 100, in the second operation mode, dehumidification performed in the desiccant block 23 is added, and further, the air flowing through the air passage B is heated by the second heat exchanger 15, so that the air passage B It is possible to make the air flowing through the state of point g shown in FIG. 3, that is, in a state of high temperature and low absolute humidity, and a relative humidity of about 20% or less. Air having a relative humidity of about 20% or less is suitable for drying applications. For example, when such air is directly applied to an object to be dried such as laundry, drying of the object to be dried is greatly accelerated, so that the drying function of the air conditioner 100 is improved.

  Moreover, in the air conditioning apparatus 100, since the common wind path B is used by the 1st operation mode and the 2nd operation mode, it is suppressed that the air conditioning apparatus 100 enlarges, and dehumidification performance is improved. However, cost performance is improved. Moreover, it is suppressed that the air path structure in the housing | casing 1 of the air conditioning apparatus 100 is complicated, a maintenance performance is improved, improving a dehumidification performance.

  Further, in the air conditioner 100, the temperature of the intake air is equal to or lower than a preset reference temperature in the temperature determination unit 91 of the control device 90 when switching to the second operation mode or when executing the second operation mode. If it is determined that there is, the third operation mode setting unit 92 of the control device 90 stops the compressor 11 immediately after that or after the set standby time has elapsed. Therefore, when the second operation mode is performed in a state where the temperature of the air sucked into the air conditioning apparatus 100 is low, frost formation on the first heat exchanger 13 is suppressed, and the refrigeration cycle. The amount of dehumidification in the dehumidification performed by the cooling action is ensured over a long period of time, and the operation efficiency of the refrigeration cycle is improved.

  That is, dehumidification performance that is possible because the air conditioner 100 performs dehumidification by the desiccant block 23 and the first heat exchanger 13 disposed on the upstream side in the second operation mode. When the temperature of the intake air is determined to be equal to or lower than a preset reference temperature, the third operation mode setting unit 92 that stops the compressor 11 causes the existing equipment to be Realized while utilizing.

Embodiment 2. FIG.
An air conditioner according to Embodiment 2 will be described.
Note that description overlapping or similar to that in Embodiment 1 is appropriately simplified or omitted.
<Dehumidifying operation of air conditioner>
Below, the dehumidification operation | movement of the air conditioning apparatus which concerns on Embodiment 2 is demonstrated.

In the air conditioning apparatus 100, the temperature determination unit 91 of the control device 90 is based on the detection signal of the temperature / humidity sensor 81 when switching to the second operation mode or when executing the second operation mode. Is less than or equal to a preset reference temperature. Then, when the temperature determination unit 91 of the control device 90 determines that the temperature of the intake air is equal to or lower than a preset reference temperature, immediately after that or after the set standby time has elapsed, The three operation mode setting unit 92 shifts the defrosting operation to the third operation mode. The third operation mode is an operation mode in which moisture is adsorbed to the desiccant block 23 in a state where the surface temperature of the first heat exchanger 13 is higher than the surface temperature of the first heat exchanger 13 in the second operation mode. It is. The standby time is the time until clogging due to frosting occurs in the first heat exchanger 13, which is stored or calculated in the third operation mode setting unit 92. The waiting time may be set to a different time according to the temperature of the intake air. That is, the standby time may be set to a shorter time as the temperature of the intake air is lower. When the third operation mode is continued and an appropriate amount of moisture is adsorbed to the desiccant block 23, the control device 90 switches the flow path of the four-way valve 12 and shifts to the first operation mode.
The operation in the third operation mode will be described below.

(Operation of the refrigeration cycle in the third operation mode)
In the third operation mode, in the second operation mode, the opening degree of the expansion valve 14 is increased in a state where the flow path of the four-way valve 12 is switched to the flow path indicated by the dotted line in FIG. That is, in the third operation mode, the refrigerant evaporation temperature in the first heat exchanger 13 is increased. In the third operation mode, the rotation speed of the compressor 11 may be decreased, and the evaporation temperature of the refrigerant in the first heat exchanger 13 may be increased. The change amount of the opening degree of the expansion valve 14 and the change amount of the rotation speed of the compressor 11 may be different change amounts according to the temperature of the intake air. That is, the opening degree of the expansion valve 14 is preferably set to a larger opening degree as the temperature of the intake air is lower. Moreover, the rotation speed of the compressor 11 is good to be set to a low rotation speed, so that the temperature of suction air is low.

(Air operation in the third operation mode)
In the third operation mode, driving of the fan 24 in the second operation mode is continued. Therefore, the air around the air conditioner 100 is dehumidified by the first heat exchanger 13, then flows into the desiccant block 23, moisture is adsorbed by the desiccant block 23, and further dehumidified. The air flowing out from the desiccant block 23 is then heated by the second heat exchanger 15, flows into the fan 24, and is discharged from the air outlet 5 to the outside of the air conditioner 100.

<Operation of air conditioner>
Below, the effect | action of the air conditioning apparatus which concerns on Embodiment 2 is demonstrated.
In the air conditioner 100, the temperature of the intake air is equal to or lower than a preset reference temperature in the temperature determination unit 91 of the control device 90 when switching to the second operation mode or when executing the second operation mode. If it determines, immediately after that or after the set standby time elapses, the third operation mode setting unit 92 of the control device 90 increases the evaporation temperature of the refrigerant in the first heat exchanger 13. Therefore, when the second operation mode is performed in a state where the temperature of the air sucked into the air conditioning apparatus 100 is low, frost formation on the first heat exchanger 13 is suppressed, and the refrigeration cycle. The amount of dehumidification in the dehumidification performed by the cooling action is ensured over a long period of time, and the operation efficiency of the refrigeration cycle is improved.

  That is, dehumidification performance that is possible because the air conditioner 100 performs dehumidification by the desiccant block 23 and the first heat exchanger 13 disposed on the upstream side in the second operation mode. And the third operation mode in which the further improvement of the operation efficiency increases the evaporation temperature of the refrigerant in the first heat exchanger 13 when it is determined that the temperature of the intake air is equal to or lower than a preset reference temperature. The setting unit 92 is realized while utilizing existing equipment.

  As mentioned above, although Embodiment 1 and Embodiment 2 were demonstrated, this invention is not limited to description of each embodiment. For example, it is possible to combine all or a part of each embodiment, each modification, and the like.

  DESCRIPTION OF SYMBOLS 1 Case, 2 Air channel room, 3 Machine room, 4 Suction inlet, 5 Air outlet, 6 Inspection window, 7 Lid, 11 Compressor, 12 Four-way valve, 13 1st heat exchanger, 14 Expansion valve, 15 2nd Heat exchanger, 21 Drain pan, 22 Air path forming plate, 23 Desiccant block, 24 Fan, 81 Temperature / humidity sensor, 90 Control device, 91 Temperature determination unit, 92 Third operation mode setting unit, 100 Air conditioner, A Refrigerant circulation Circuit, B Airway.

Claims (9)

A refrigerant circulation circuit in which a compressor, a flow path switching device, a first heat exchanger, a decompression device, and a second heat exchanger are sequentially connected by piping;
A desiccant material disposed between the first heat exchanger and the second heat exchanger;
An air blower that generates an airflow that passes in the order of the first heat exchanger, the desiccant material, and the second heat exchanger;
Temperature detecting means for detecting the temperature of the airflow;
By controlling the flow path switching device, the first heat exchanger acts as a condenser or a radiator, and the second heat exchanger acts as an evaporator, so that the moisture held in the desiccant material is reduced. A first operation mode to be desorbed and a second operation in which the first heat exchanger acts as an evaporator and the second heat exchanger acts as a condenser or a radiator to adsorb moisture to the desiccant material. A control device for switching between modes,
The controller is
Temperature determining means for determining whether the temperature of the airflow detected by the temperature detecting means is low or high;
When the temperature determining means determines that the temperature of the airflow is low, the surface temperature of the first heat exchanger is higher than the surface temperature of the first heat exchanger in the second operation mode. An air conditioner comprising: a third operation mode setting means for causing the desiccant material to adsorb moisture and shifting to a third operation mode.   The air conditioner according to claim 1, wherein the control device stops the compressor in the third operation mode.   In the third operation mode, the control device is configured such that the refrigerant evaporation temperature in the first heat exchanger is higher than the refrigerant evaporation temperature in the first heat exchanger in the second operation mode. The air conditioning apparatus according to claim 1.   4. The air conditioner according to claim 3, wherein, in the third operation mode, the control device makes the pressure reduction amount of the pressure reduction device smaller than the pressure reduction amount of the pressure reduction device in the second operation mode.   5. The air conditioner according to claim 3, wherein the control device lowers the rotation speed of the compressor in the third operation mode as compared with the rotation speed of the compressor in the second operation mode. apparatus.   When the temperature determining unit determines that the temperature of the airflow is low at the time of switching to the second operation mode or executing the second operation mode, the third operation mode setting unit immediately The air conditioner according to any one of claims 1 to 5, wherein the air conditioner is shifted to a third operation mode. The third operation mode setting means includes
Store or calculate the waiting time until the third operation mode is shifted,
When the temperature determination means determines that the temperature of the airflow is low when switching to the second operation mode or when executing the second operation mode, the third operation mode is entered after the standby time has elapsed. The air-conditioning apparatus according to any one of claims 1 to 5, which is shifted.   The air conditioner according to any one of claims 1 to 7, wherein the refrigerant circulating in the refrigerant circuit includes an R410A refrigerant, an HFC refrigerant, an HC refrigerant, an HFO refrigerant, or a natural refrigerant. A refrigerant circulation circuit in which a compressor, a flow path switching device, a first heat exchanger, a decompression device, and a second heat exchanger are sequentially connected by piping;
A desiccant material disposed between the first heat exchanger and the second heat exchanger;
An air blower that generates an airflow that passes in the order of the first heat exchanger, the desiccant material, and the second heat exchanger;
Temperature detecting means for detecting the temperature of the airflow,
Using the flow path switching device, the first heat exchanger acts as a condenser or a radiator, and the second heat exchanger acts as an evaporator to desorb moisture held in the desiccant material. A first operation mode that allows the first heat exchanger to act as an evaporator, and a second operation mode in which the second heat exchanger acts as a condenser or a radiator to adsorb moisture to the desiccant material. And a method of controlling the air conditioner,
Determining whether the temperature of the airflow detected by the temperature detecting means is low or high,
When it is determined that the temperature of the airflow is low, the desiccant material is in a state where the surface temperature of the first heat exchanger is higher than the surface temperature of the first heat exchanger in the second operation mode. The control method of the air conditioner which transfers to the 3rd operation mode which makes water adsorb | suck to the air.

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