JP5484937B2 - Outdoor unit and air conditioner - Google Patents

Description

  The present invention relates to an outdoor unit and an air conditioner suitable for preventing damage to an outdoor fan caused by snow or ice.

  In regions where there is snow in the winter, snow may blow into the outdoor unit of the air conditioner, which may be caused by snow blown into the outdoor unit, snow attached to an outdoor fan (a fan installed in the outdoor unit), or icicles. It is known that outdoor fan breakage often occurs.

  As a method for solving this problem, a method is known in which snow is blown into the outdoor unit and snow is prevented from adhering to the outdoor fan by intermittently rotating the outdoor fan (see, for example, Patent Document 1). .)

  In addition, a heater is added to the drain pan of the outdoor unit.When the outdoor fan is rotating during heating operation, the heater is energized, and the heat generated by the heater melts snow, etc., and drains it outside the outdoor unit. The method of doing is also known. In this method, for the purpose of preventing abnormal overheating of the heater, the heater is not energized when the operation of the air conditioner is stopped and the outdoor fan is stopped. That is, only the intermittent operation of the outdoor fan described above prevents snow from blowing into the outdoor unit while the heating operation is stopped.

Japanese Patent No. 3300366

As described above, the method of intermittently rotating the outdoor fan can prevent snow from blowing into the outdoor unit, but has the following problems.
That is, the outdoor unit is provided with a drain pan that discharges condensed water, rain blown from outside, water melted by snow, and the like to the outside. In winter, the water freezes and the drain hole of the drain pan is blocked, and it may not be possible to drain the outdoor unit to the outside. As a result, there is a problem that snow and ice easily accumulate inside the outdoor unit, and the outdoor fan is easily damaged. Such a problem could not be solved by the above-described method of intermittently rotating the outdoor fan.

As a method for solving the above-described problem, a method is known in which a heater is added to the drain pan of the outdoor unit, and the heater is energized when the outdoor fan is rotated during the heating operation of the air conditioner. In this method, the water on the drain pan is prevented from freezing by the heat generated by the heater, and the drain hole is prevented from being blocked by ice.
However, in the method using the heater, the heater is not energized when the operation of the air conditioner is stopped and the outdoor fan is stopped for the purpose of preventing abnormal overheating of the heater. That is, while the operation of the air conditioner is stopped, only the intermittent operation of the outdoor fan described above is performed, and the problem that the outdoor fan is easily damaged remains.

  The present invention has been made to solve the above-described problems, and provides an outdoor unit and an air conditioner that can more reliably prevent snow blowing and damage to an outdoor fan due to snow adhesion. For the purpose.

In order to achieve the above object, the present invention provides the following means.
The outdoor unit of the present invention is an outdoor unit that constitutes an air conditioner together with the indoor unit, and takes in outdoor air from the outside of the housing and exchanges heat in the outdoor heat exchanger, the outdoor heat exchanger, A heating unit that is disposed below the outdoor air blowing unit and heats a drainage unit that discharges water inside the housing to the outside, and a control unit that controls the operation of the outdoor air blowing unit and the heat generation of the heating unit. When the heating operation of the air conditioner is provided and stopped, the control unit performs intermittent operation of the outdoor air blowing unit, and further starts heating by the heating unit after the end of the intermittent operation. It is characterized by.

According to the present invention, even when the heating operation is stopped, since the intermittent operation of the outdoor air blowing unit and the heating by the heating unit are performed, compared with the case where only the intermittent operation of the outdoor air blowing unit is performed. In addition, the outdoor blower and the heat exchanger are reliably prevented from being damaged by snow and ice.
Further, the heat generated by the heating unit is not taken away by the outdoor air flowing around the heating unit by the outdoor air blowing unit. Therefore, the ratio used to melt snow and ice out of the heat generated in the heating unit is increased, and compared with the case where the intermittent operation of the outdoor air blowing unit and the heating by the heating unit are performed simultaneously, the heating unit Increases the efficiency of melting snow and ice. As a result, it is possible to reliably prevent the outdoor blower from being damaged by snow or ice.
On the other hand, when it is not necessary to increase the ability to melt snow and ice, it is possible to reduce the power consumed by the outdoor air blowing unit and the heating unit in order to melt the snow and ice.

  The outdoor unit of the present invention is an outdoor unit that constitutes an air conditioner together with the indoor unit, and takes in outdoor air from the outside of the housing and exchanges heat in the outdoor heat exchanger, the outdoor heat exchanger, A heating unit that is disposed below the outdoor air blowing unit and heats a drainage unit that discharges water inside the housing to the outside, and a control unit that controls the operation of the outdoor air blowing unit and the heat generation of the heating unit. Provided, when the heating operation of the air conditioner is stopped, the control unit performs an intermittent operation of the outdoor air blowing unit, and further starts heating by the heating unit after the intermittent operation starts, The heating by the heating unit is terminated after the intermittent operation is started.

  According to the present invention, even when the heating operation is stopped, since the intermittent operation of the outdoor air blowing unit and the heating by the heating unit are performed, compared with the case where only the intermittent operation of the outdoor air blowing unit is performed. In addition, the outdoor blower and the heat exchanger are reliably prevented from being damaged by snow and ice.

  In the said invention, it is desirable that the heating period by the said heating part is preset according to the capacity | capacitance of the said heating part.

  According to the present invention, overheating by the heating unit is prevented, and occurrence of breakage of the outdoor fan due to snow or ice is prevented. In other words, when the capacity of the heating unit is relatively large, the amount of heat generation is large and the ability to melt snow and ice is high, so it is possible to melt snow and ice in a short period of time, so the heating period is shortened and overheating occurs Is prevented. On the other hand, when the capacity of the heating unit is relatively small, the heat generation amount is small and the ability to melt snow and ice is low, so by setting a longer period for generating heat, snow and ice remain unmelted. This prevents the outdoor blower from being damaged.

  In the above invention, a temperature measuring unit that measures at least one temperature of the casing, the outdoor air blowing unit, and the drainage unit is further provided, and the control unit is configured so that the heating unit has a temperature measuring unit at the end of heating by the heating unit. When the measured value is less than a predetermined value, it is desirable that the next operation period by the outdoor blower is longer than the previous operation period.

  According to the present invention, the amount of snow blown into the outdoor unit can be suppressed to an amount that can be melted by heating by the heating unit, and damage to the outdoor air blowing unit due to snow or ice can be prevented.

In other words, when snow or ice remains in the portion where the temperature measurement unit is disposed, the heat is used to melt the snow or ice even if heating by the heating unit is performed. Therefore, the temperature of the portion where the temperature measuring unit is arranged does not increase. Then, when the snow and ice of the said part melt | dissolve and dry, the temperature of the said part will begin to rise with the heat which generate | occur | produced in the heating part.
If the measured value by the temperature measurement unit is less than the specified value, it may be that snow, ice, water, etc. remain. The heating by the heating unit melts the snow and ice and drains the melted water out of the outdoor unit. This is considered insufficient.

  In such a case, the amount of snow accumulated in the outdoor unit and the amount of ice adhering to the inside of the outdoor unit can be reduced by lengthening the operation time of the outdoor blowing unit and reducing the amount of snow blown into the outdoor unit. Thereby, it is possible to melt the snow accumulated in the outdoor unit and the attached ice without changing the heating of the heating unit, and drain the melted water outside the outdoor unit.

Examples of the predetermined value include the temperature at which ice melts, the temperature of snow that has accumulated and the temperature of water.
Here, the place where the temperature measurement unit is placed is a place where snow is likely to accumulate, a place where ice is easily attached, or a place where snow or ice melted water remains until the end (for example, the lowest part of the drainage part). It can be illustrated.

  In the above-mentioned invention, a temperature measuring unit that measures at least one temperature of the casing, the outdoor air blowing unit, and the drainage unit is further provided, and the control unit measures the temperature measuring unit during heating by the heating unit. When the value starts to increase, it is desirable to end the heating by the heating unit.

  According to the present invention, since the heating period by the heating unit can be adjusted to a length suitable for melting snow and ice, overheating by the heating unit is prevented, and the outdoor air blowing unit by snow and ice is prevented. Damage is prevented from occurring.

In other words, when snow or ice remains in the portion where the temperature measurement unit is disposed, the heat is used to melt the snow or ice even if heating by the heating unit is performed. Therefore, the temperature of the portion where the temperature measuring unit is arranged does not increase. Then, when the snow and ice of the said part melt | dissolve and dry, the temperature of the said part will begin to rise with the heat which generate | occur | produced in the heating part.
By adjusting the length of the heating period based on this temperature change, heating by the heating unit will continue even if there is no snow or ice, or heating by the heating unit will end even if snow or ice remains It will not be done.

  Specific examples of the case where the measured value starts to rise include a case where the rate of change in temperature is greater than or equal to a predetermined rate of change, or a case where the temperature is higher than a predetermined temperature of 0 ° C. or higher. Can do.

  In the above invention, the outdoor air blowing unit is an outdoor fan that blows outdoor air by being driven to rotate, and the control unit rotates the outdoor fan by the flow of the outdoor air while the intermittent operation is stopped. It is desirable that the outdoor fan is rotated at a rotation speed based on the detected rotation speed during the intermittent operation.

  According to the present invention, the outdoor fan can be rotationally driven at the minimum number of revolutions necessary to prevent snow from blowing into the outdoor unit, and snow can be reliably prevented from blowing into the outdoor unit, and the outdoor fan can be prevented. It is possible to reduce power consumption by driving.

  In other words, when snow blows into the outdoor unit while the outdoor fan is intermittently stopped, air flows in the direction of blowing snow inside the outdoor unit. The outdoor fan is rotated by the air flow, and the rotation speed is proportional to the speed of the air flow. By detecting this number of revolutions, the control unit can determine the minimum number of revolutions of the outdoor fan necessary to prevent snow from blowing into the outdoor unit.

  Therefore, compared to the case where the rotational speed of the outdoor fan is fixed at a constant value during intermittent operation, even if the snow blows stronger and snow blows into the outdoor unit at a constant rotational speed, the outdoor fan The number of rotations can be increased to prevent blowing. On the other hand, when the snow blows weak, the number of revolutions of the outdoor fan can be reduced to reduce the power consumed by the outdoor fan.

  In the above invention, when power is supplied after power supply to the air conditioner is stopped, the control unit operates the outdoor air blowing unit for a predetermined period longer than the intermittent operation period. It is desirable to perform heating by the heating unit.

  ADVANTAGE OF THE INVENTION According to this invention, the snow and ice which accumulate | stored inside the outdoor unit etc. during the stop of electric power supply can be removed by the time of the first starting of an air conditioner.

  The air conditioner of the present invention is characterized in that an indoor unit and the outdoor unit of the present invention are provided.

  According to the present invention, since the outdoor unit of the present invention is provided, it is possible to more reliably prevent the blowing of snow and the breakage of the outdoor air blowing section due to the adhesion of snow.

  According to the outdoor unit and the air conditioner of the present invention, when the heating operation of the air conditioner is stopped, the outdoor fan is intermittently operated, and further, heating by the heating unit is started after the intermittent operation is finished. By doing so, it is possible to more reliably prevent the blowout of snow and the breakage of the outdoor fan due to the adhesion of snow.

1 is a perspective view showing an air conditioner according to a first embodiment of the present invention. It is a perspective view which shows the structure of the outdoor unit of FIG. It is the elements on larger scale explaining the arrangement | positioning relationship of the outdoor fan of FIG. 2, a compressor, and a drain pan. It is the elements on larger scale explaining the arrangement | positioning relationship of the drain pan of FIG. 3, and a heater. It is a block diagram explaining the structure of the control part of FIG. It is a timing chart explaining operation | movement of the outdoor fan and heater in the snow prevention control of 1st Embodiment. It is a block diagram explaining another structure in the control part of FIG. It is a block diagram explaining the structure of the control part of the air conditioner which concerns on the 1st modification of the 1st Embodiment of this invention. It is a block diagram explaining the structure of the control part in the air conditioner of the 2nd modification of the 1st Embodiment of this invention. It is a timing chart explaining operation | movement of the outdoor fan and heater of the snow prevention control which concern on the air conditioner in the 2nd Embodiment of this invention. It is a block diagram explaining the structure of the control part in the air conditioner of the 3rd Embodiment of this invention.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing an air conditioner according to the present embodiment, and FIG. 2 is a perspective view showing a configuration of the outdoor unit of FIG.
As shown in FIG. 1, the air conditioner 10 includes an indoor unit 20 and an outdoor unit 30. The indoor unit 20 and the outdoor unit 30 are connected to each other by a refrigerant pipe 40 through which the refrigerant conducts, electric wiring (not shown), and the like. Two refrigerant pipes 40 are provided, and the refrigerant flows from the indoor unit 20 to the outdoor unit 30 on one side and from the outdoor unit 30 to the indoor unit 20 on the other side.

  The indoor unit 20 is configured such that a rear base (not shown) and a front panel 21 are integrally formed. The base includes various devices such as a plate fin tube type indoor heat exchanger 22, a substantially cylindrical cross flow fan 23, and a control unit 24 composed of various electric circuit elements for controlling the operation of the indoor unit 20. It has been.

  The front panel 21 has suction grilles 21a formed on the front and top surfaces, respectively. Indoor air is sucked into the indoor unit 20 from multiple directions by these suction grille portions 21a. In addition, an air filter 21b is provided behind the suction grille portion 21a to remove dust such as sucked air. Further, the front panel 21 is formed with an air outlet 21c below, from which warmed air or cooled air is blown out. The air suction and air blowing are performed by the rotation of the cross flow fan 23.

  As shown in FIG. 1 or FIG. 2, the outdoor unit 30 includes an outdoor heat exchanger 32, an outdoor fan (outdoor blower unit) 33, a compressor 34, a drain pan (drainage unit) 41, and a heater (heating) in a housing 31. Part) 42 and an electrical equipment box 50 in which the control unit 43 is housed. As shown in FIGS. 2 to 4, the outdoor unit 30 is provided with a baffle plate 35 that divides the space in the outdoor unit 30 into two substantially at the center.

  An outdoor fan 33 is disposed in a space on the left side (left side in FIG. 2) of the outdoor unit 30, and a compressor 34 is disposed in a space on the right side (right side in FIG. 2). As shown in FIG. 2, an electrical box 50 is disposed above the compressor 34, and the left end of the electrical box 50 protrudes beyond the baffle plate 35 into a space where the outdoor fan 33 is disposed. Has been placed.

  The outdoor heat exchanger 32 is configured by a refrigerant pipe having a large number of corrugated fins around it, and realizes heat exchange between the refrigerant and the outdoor air. The outdoor fan 33 is provided in order to constantly take new air into the casing 31 and improve heat exchange efficiency. When the outdoor fan 33 is rotationally driven, a wind is generated in the housing 31 from the outdoor heat exchanger 32 to the outdoor fan 33.

  Note that a fingered (not shown) and a fan guard 36 are provided on the back and front of the casing 31 where the outdoor heat exchanger 32 and the outdoor fan 33 face each other. The fingered is provided so that the corrugated fin is not damaged by an unexpected impact from the outside. Similarly to this, the fan guard 36 is provided for the purpose of protecting the outdoor fan 33 from external impacts and for the purpose of preventing dust contained in the outside air from being taken into the housing 31. Is.

FIG. 3 is a partially enlarged view for explaining the arrangement relationship of the outdoor fan, the compressor, and the drain pan of FIG.
As shown in FIGS. 2 and 3, the outdoor fan 33 is provided with a propeller 33 a and a motor 33 b.
The propeller 33a is driven to rotate to generate wind that flows from the outdoor heat exchanger 32 to the outdoor fan 33. In this embodiment, the propeller 33a is applied to an example in which three blades are provided. To explain. In addition, a well-known thing can be used as the propeller 33a, It does not specifically limit.
The motor 33b generates rotational driving force when electric power is supplied, and rotates the propeller 33a. As shown in FIG. 3, the motor 33b is attached to a drain pan 41 and attached to a frame 33c extending upward. As the motor 33b, any known motor can be used as long as it can control the rotation speed, and it is not particularly limited.

  The compressor 34 converts the low-temperature and low-pressure gas refrigerant into a high-temperature and high-pressure gas refrigerant and discharges it. The compressor 34 plays the most central role among the components constituting the refrigerant circuit. Here, the refrigerant circuit means, in addition to the compressor 34, an indoor heat exchanger 22, an outdoor heat exchanger 32, a refrigerant pipe 40, an expansion valve, and a four-way valve that defines the flow direction of the refrigerant (an expansion valve and a four-way valve). Is a circuit that circulates the refrigerant between the indoor unit 20 and the outdoor unit 30.

FIG. 4 is a partially enlarged view illustrating the positional relationship between the drain pan and the heater in FIG.
As shown in FIGS. 2 to 4, the drain pan 41 is disposed at the lower part of the casing 31 and guides the water inside the outdoor unit 30 to the outside. More specifically, it is arranged at the lower part of the space on the left side (left side in FIG. 2) in the front view of the outdoor unit 30, in other words, the space where the outdoor heat exchanger 32 and the outdoor fan 33 are arranged. The moisture condensed on the outdoor heat exchanger 32 and the water melted by snow and ice are guided to the outside of the outdoor unit 30.
The drain pan 41 is provided with a drain hole 41 a that guides moisture from the inside of the outdoor unit 30 to the outside.

  As shown in FIGS. 3 and 4, the heater 42 is disposed on the upper surface of the drain pan 41, and generates heat when supplied with electric power. In the present embodiment, the heaters 42 are arranged so as to extend along the three sides of the drain pan 41. A known heater can be used as the heater 42 and is not particularly limited.

FIG. 5 is a block diagram illustrating the configuration of the control unit in FIG.
As shown in FIG. 5, the control unit 43 controls rotation of the outdoor fan 33, heat generation in the heater 42, and the like. The control unit 43 is housed inside the electrical box 50 together with an inverter unit (not shown) that controls the rotation of the compressor 34.
The control unit 43 receives the temperature of the outdoor air measured by the outdoor temperature sensor 61, and a control signal for controlling the rotational speed of the outdoor fan 33 is output from the control unit 43 to the motor 33 b of the outdoor fan 33, and the heater 42. A control signal for controlling the heat generation is output from the control unit 43 to the heater 42.
Control of outdoor fan 33 and heater 42 by control unit 43 will be described later.

  The outside air temperature sensor 61 is a temperature sensor disposed in the outdoor unit 30 and is a known means for measuring the temperature of a thermocouple, thermistor, etc., and is not particularly limited.

  Next, the operation of the air conditioner 10 having the above-described configuration will be described separately for the heating operation and the cooling operation.

  First, at the time of heating operation, the high-temperature and high-pressure gaseous refrigerant in the compressor 34 is pumped to the indoor heat exchanger 22 of the indoor unit 20 through the refrigerant pipe 40 as shown in FIG. In the indoor unit 20, heat is applied from the high-temperature and high-pressure refrigerant flowing through the indoor heat exchanger 22 to the indoor air taken in from the suction grille portion 21 a by the cross flow fan 23. Thereby, warm air is blown out from the blower outlet 21c. At the same time, the high-temperature and high-pressure gaseous refrigerant is condensed and liquefied in the indoor heat exchanger 22 to become a high-temperature and high-pressure liquid refrigerant.

  The high-temperature and high-pressure liquid refrigerant is decompressed by the expansion valve while being sent to the outdoor heat exchanger 32 of the outdoor unit 30, and becomes a low-temperature and low-pressure liquid refrigerant. In the outdoor unit 30, the low-temperature and low-pressure liquid refrigerant flowing through the outdoor heat exchanger 32 takes heat from new outdoor air taken into the housing 31 by the outdoor fan 33. The low-temperature and low-pressure liquid refrigerant evaporates and vaporizes by taking heat, and becomes a low-temperature and low-pressure gas refrigerant. This is sent again to the compressor 34, and the above process is repeated.

  During the cooling operation, the refrigerant flows in the refrigerant circuit in the opposite direction to the above. That is, the high-temperature and high-pressure gaseous refrigerant in the compressor 34 passes through the refrigerant pipe 40 and is pumped to the outdoor heat exchanger 32, where the outdoor air is deprived of heat and condensed and liquefied. Become. The high-temperature and high-pressure liquid refrigerant is decompressed by the expansion valve to become a low-temperature and low-pressure liquid refrigerant, and is sent again to the indoor heat exchanger 22 through the refrigerant pipe 40. Here, the low-temperature and low-pressure liquid refrigerant takes heat from the indoor unit and blows out cold air from the outlet 21c, and the refrigerant itself evaporates to become a low-temperature and low-pressure gaseous refrigerant. This is sent again to the compressor 34, and the above process is repeated.

Next, the snow prevention control during the heating operation stop, which is a feature of the present embodiment, will be described.
The controller 43 starts the snow prevention control when the heating operation of the air conditioner 10 is stopped and a predetermined condition is satisfied. In the present embodiment, as shown in FIG. 5, the intermittent operation of the outdoor fan 33 is started when the temperature measured by the outside air temperature sensor 61 is equal to or lower than the first threshold value (for example, 4 ° C.), and the second threshold value (for example, 2 ° C.). This will be applied to an example in which the heat generation control of the heater 42 is started at the following times.
This is because there is a difference between the temperature (first threshold value) at which the possibility of snow blowing due to snowfall is high and the temperature (second threshold value) at which the possibility of ice adhesion is high. By doing in this way, the electric power consumed can be suppressed compared with the case where the intermittent operation of the outdoor fan 33 and the heat generation control of the heater 42 are started at the same temperature.

FIG. 6 is a timing chart for explaining the operation of the outdoor fan and the heater in the snow prevention control of this embodiment.
When the snow prevention control is started, the control unit 43 starts intermittent operation of the outdoor fan 33 as shown in FIG. In this embodiment, the outdoor fan 33 is rotationally driven at intervals of 10 minutes, and intermittent operation is performed in which the period of one rotational drive is 5 minutes. In other words, the rotation drive for 5 minutes and the rotation stop for 5 minutes are repeated.

  On the other hand, the control unit 43 starts control for causing the heater 42 to generate heat intermittently. In the present embodiment, the heater 42 starts to generate heat from the time when the rotation drive of the outdoor fan 33 is stopped, and control is performed so that one heat generation period (continuous heat generation period) is 2 minutes. In other words, heat generation for 2 minutes and heat generation stop for 8 minutes are repeated.

  Here, the one heat generation period in the heater 42 is a period that can be changed according to the capacity of the heater 42, and is not particularly limited to 2 minutes. That is, it can be arbitrarily set in a range from a period necessary for melting snow and ice in the outdoor unit 30 to a period during which overheating by the heater 42 occurs.

  When the outdoor fan 33 is driven to rotate, wind is generated in the housing 31 from the outdoor heat exchanger 32 to the outdoor fan 33, and the blowing of snow from the fan guard 36 side into the housing 31 is suppressed, or Is prevented. When the rotation of the outdoor fan 33 is stopped, next, power is supplied to the heater 42 and heat generation is started. Then, the snow accumulated in the casing 31, particularly on the drain pan 41, and the ice attached to the drain pan 41 are melted by the heat of the heater 42 and discharged outside the outdoor unit.

  According to the above configuration, since the intermittent operation of the outdoor fan 33 and the heating by the heater 42 are performed even while the heating operation is stopped, compared with the case where only the intermittent operation of the outdoor fan 33 is performed. Thus, the outdoor fan 33 and the outdoor heat exchanger 32 can be reliably prevented from being damaged by snow and ice.

The heat generated by the heater 42 is not taken away by the outdoor air flowing around the heating unit by the outdoor fan 33. For this reason, the proportion of heat generated in the heater 42 used to melt snow and ice is increased, and compared with the case where the intermittent operation of the outdoor fan 33 and the heating by the heater 42 are performed simultaneously, Increases the efficiency of melting snow and ice. As a result, the outdoor fan 33 and the outdoor heat exchanger 32 can be reliably prevented from being damaged by snow and ice.
On the other hand, when there is no need to increase the ability to melt snow and ice, the power consumed by the outdoor fan 33 and the heater 42 to melt snow and ice can be reduced.

  By limiting the heat generation period (heating period) by the heater 42 to 2 minutes, overheating by the heater 42 is prevented, and damage to the outdoor fan 33 and the outdoor heat exchanger 32 due to snow and ice is prevented. That is, when the capacity of the heater 42 is relatively large, the amount of heat generation is large and the ability to melt snow and ice is high, so that snow and ice can be melted in a short period of time. Is prevented. On the other hand, when the capacity of the heater 42 is relatively small, the amount of heat generation is small and the ability to melt snow and ice is low. Therefore, by setting the heat generation period longer, it is possible that unmelted snow and ice will occur. This prevents the outdoor fan 33 and the outdoor heat exchanger 32 from being damaged.

FIG. 7 is a block diagram illustrating another configuration of the control unit in FIG.
Note that the control unit 43 may determine the start of the snow prevention control based on the temperature of the outdoor air detected by the outdoor temperature sensor 61 as in the above-described embodiment, or the snowfall sensor 62 provided in the outdoor unit 30. The start of the snow prevention control may be determined based on the detection signal, and is not particularly limited.
By doing in this way, snow prevention control is performed only in the situation where there is actually snowfall and snow blowing occurs.

[First Modification of First Embodiment]
Next, a first modification of the first embodiment of the present invention will be described with reference to FIG.
The basic configuration of the air conditioner of the present modification is the same as that of the first embodiment, but differs from the first embodiment in the control of the heat generation period in the heater. Therefore, in this modification, only control of the heat generation period in the heater will be described with reference to FIG. 8, and description of other components and the like will be omitted.
FIG. 8 is a block diagram illustrating a configuration of a control unit in the air conditioner of the present modification.
In addition, about the component same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 8, the control unit 143 of the air conditioner 110 according to the present modification includes the temperature of the outdoor air measured by the outside air temperature sensor 61 and the drain pan measured by the temperature sensor (temperature measurement unit) 163. A temperature of 41 is input. On the other hand, a control signal for controlling the rotation speed of the outdoor fan 33 is output from the control unit 143 to the motor 33b of the outdoor fan 33, and a control signal for controlling heat generation in the heater 42 is output from the control unit 143 to the heater 42. Yes.
Control of outdoor fan 33 and heater 42 by control unit 143 will be described later.

  The temperature sensor 163 is a temperature sensor disposed in the outdoor unit 30 and is a known temperature detection unit such as a thermocouple or a thermistor, and is not particularly limited. The temperature sensor 163 is provided in a place where snow in the outdoor unit 30 accumulates, a place where ice easily adheres, or a place where water where snow or ice melts easily accumulates. In the present embodiment, description will be made by applying to an example provided in the drain pan 41.

  Next, the operation of the air conditioner 110 having the above configuration will be described. Since the operation of the air conditioner 110 during the heating operation and the cooling operation is the same as that of the first embodiment, the description thereof is omitted.

Here, the snow prevention control during the heating operation stop, which is a feature of this modification, will be described.
When the snow prevention control is first started, the control unit 143 starts the intermittent operation of the outdoor fan 33 as in the first embodiment. Then, the heater 42 starts to generate heat from the time when the rotational drive of the outdoor fan 33 is stopped.

  When the temperature of the drain pan 41 measured by the temperature sensor 163 has not risen above a predetermined value at the time when the heat generation in the heater 42 is completed for 2 minutes, the control unit 143 drives the next outdoor fan 33 to rotate. Control to lengthen the period. In the case of the present embodiment, control is performed for a period longer than 5 minutes.

As the case where the temperature of the drain pan 41 has not risen, it is estimated that the snow that has accumulated on the drain pan 41 remains unmelted, the case where it is estimated that the attached ice remains unmelted, A case where it is estimated that water in which snow or ice has melted remains in the drain pan 41 is mentioned.
Thus, the amount of snow blown into the outdoor unit 30 can be reduced by lengthening the operation period of the outdoor fan 33.

  According to the above configuration, the amount of snow blown into the outdoor unit 30 can be suppressed to an amount that can be melted by heating by the heater 42, and damage to the outdoor fan 33 due to snow or ice can be prevented.

That is, when snow or ice remains in the portion where the temperature sensor 163 is disposed, the heat is used to melt the snow or ice even if the heater 42 is heated. Therefore, the temperature of the portion where the temperature sensor 163 is disposed does not increase. Thereafter, when the snow or ice in the part melts and dries, the temperature of the part starts to rise due to the heat generated in the heater 42.
When the measured value by the temperature sensor 163 is less than the predetermined value, it is considered that snow, ice, water or the like remains, and it is considered that heating by the heater 42 is insufficient to melt the snow or ice.

  In such a case, by increasing the operation time of the outdoor fan 33 and reducing the amount of snow blown into the outdoor unit 30, the amount of snow accumulated in the outdoor unit 30 and the amount of attached ice can be reduced. As a result, it is possible to melt the snow accumulated in the outdoor unit 30 and the attached ice without changing the heating of the heater 42.

  Here, examples of the predetermined value include the temperature at which ice melts, the temperature of snow that has accumulated, and the temperature of water.

Note that, as in the above-described modification, control for changing the operation period of the outdoor fan 33 may be performed based on the measurement value of the temperature sensor 163, or the heat generation period of the heater 42 may be changed. It is not limited.
Specifically, when the measured value by the temperature sensor 163 has not increased during the two-minute heating period in the heater 42, the heating period by the heater 42 is extended, and the heater starts when the measured value starts to increase. The heating at 42 may be terminated.

  By doing in this way, since the heat generation period (heating period) by the heater 42 can be adjusted to a length suitable for melting snow and ice, overheating by the heater 42 is prevented, and snow and ice are also prevented. This can prevent the outdoor fan 33 from being damaged.

  Specific examples of the case where the measured value starts to rise include a case where the rate of change in temperature is greater than or equal to a predetermined rate of change, or a case where the temperature is higher than a predetermined temperature of 0 ° C. or higher. Can do.

[Second Modification of First Embodiment]
Next, a second modification of the first embodiment of the present invention will be described with reference to FIG.
The basic configuration of the air conditioner of this modification is the same as that of the first embodiment, but the control of the outdoor fan during intermittent operation is different from that of the first embodiment. Therefore, in this modification, only the control of the outdoor fan during intermittent operation will be described with reference to FIG. 9, and description of other components and the like will be omitted.
FIG. 9 is a block diagram illustrating a configuration of a control unit in the air conditioner of the present modification.
In addition, about the component same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 9, the control unit 243 of the air conditioner 210 of the present modification includes an outdoor air temperature measured by the outdoor air temperature sensor 61 and an outdoor fan 33 that is rotationally driven by the flow of the outdoor air. A signal related to the rotational speed is input. On the other hand, a control signal for controlling the rotation speed of the outdoor fan 33 is output from the control unit 243 to the motor 33b of the outdoor fan 33, and a control signal for controlling heat generation in the heater 42 is output from the control unit 243 to the heater 42. Yes.
Control of the outdoor fan 33 and the heater 42 by the control unit 243 will be described later.

  The motor 33b of the outdoor fan 33 generates a driving force for rotating the propeller fan 33a when electric power is supplied from the outside, and generates electric power when the propeller fan 33a is rotationally driven by the flow of outdoor air. Is. The electric power generated by the motor 33a is input to the control unit 243, and the control unit 243 can obtain the rotation speed of the propeller fan 33a. When the motor 33b incorporates a shaft phase detection sensor such as a brushless DC motor or a rotation detection sensor, the rotational speed of the propeller fan 33a may be obtained using the sensor.

  Next, the operation of the air conditioner 210 having the above configuration will be described. Since the operation of the air conditioner 210 during the heating operation and the cooling operation is the same as in the first embodiment, the description thereof is omitted.

Here, the snow prevention control during the heating operation stop, which is a feature of this modification, will be described.
When the snow prevention control is started first, the control unit 243 starts the intermittent operation of the outdoor fan 33 as in the first embodiment. Then, the heater 42 starts to generate heat from the time when the rotational drive of the outdoor fan 33 is stopped.

  When outdoor air blows into the outdoor unit 30 while the rotational drive of the outdoor fan 33 is stopped, the propeller fan 33a is rotated by the flow of outdoor air. The rotation of the propeller fan 33a is transmitted to the motor 33b, and electric power is generated in the motor 33b. The generated electric power is input to the control unit 243, and the rotation speed of the propeller fan 33a is estimated.

Thereafter, when the operation of the outdoor fan 33 is started, the control unit 243 performs control to rotate the outdoor fan 33 at the estimated rotational speed. Here, the direction of rotation of the outdoor fan 33 by outdoor air is opposite to the direction of rotation of the outdoor fan 33 driven by receiving power.
Therefore, by the operation of the outdoor fan 33, the flow of outdoor air in the direction in which snow blows into the outdoor unit 30 is offset, and snow blowing is prevented.

  According to the above configuration, the outdoor fan 33 can be rotationally driven at the minimum number of rotations necessary to prevent snow from blowing into the outdoor unit 30, and snow blowing into the outdoor unit 30 can be reliably prevented. At the same time, it is possible to reduce power consumption due to the operation of the outdoor fan 33.

  That is, when snow blows into the outdoor unit 30 while the outdoor fan 33 is intermittently stopped, air flows in the snow blowing direction inside the outdoor unit 30. The outdoor fan 33 is rotated by this air flow, and the rotation speed is proportional to the speed of the air flow. By detecting this rotational speed, the control unit 243 can determine the minimum rotational speed of the outdoor fan 33 in order to prevent snow from blowing into the outdoor unit 30.

  Therefore, compared with the case where the rotational speed of the outdoor fan 33 is fixed to a constant value during intermittent operation, even if the snow blows stronger and snow blows into the outdoor unit 30 at a constant rotational speed, The number of rotations of the outdoor fan 33 can be increased to prevent blowing. On the other hand, when the snow blown weakens, the number of revolutions of the outdoor fan 33 can be reduced, and the power consumed by the outdoor fan 33 can be reduced.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the air conditioner of the present embodiment is the same as that of the first embodiment, but differs from the first embodiment in the heat generation period of the heater during snow prevention control. Therefore, in the present embodiment, only the heat generation period of the heater at the time of snow prevention control will be described using FIG. 10, and description of other components and the like will be omitted.
FIG. 10 is a timing chart for explaining the operation of the outdoor fan and heater for snow prevention control according to the air conditioner of this embodiment.
In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and the description is abbreviate | omitted.

  The operation of the air conditioner 10 according to the present embodiment will be described. Since the operation of the air conditioner 10 during the heating operation and the cooling operation is the same as that in the first embodiment, the description thereof is omitted.

Here, the snow prevention control during the heating operation stop, which is a feature of the present embodiment, will be described.
When the snow prevention control is first started, the control unit 43 starts heat generation of the heater 42 at the same time as the intermittent operation of the outdoor fan 33 is started as in the first embodiment, as shown in FIG. And the heat generation of the heater 42 is stopped simultaneously with the stop of the intermittent operation of the outdoor fan 33.
In other words, the rotation drive of the outdoor fan 33 and the heat generation of the heater 42 for 5 minutes, and the rotation stop of the outdoor fan 33 and the heat generation stop of the heater 42 for 5 minutes are repeated.

According to the above configuration, since the intermittent operation of the outdoor fan 33 and the heating by the heater 42 are performed even while the heating operation is stopped, compared with the case where only the intermittent operation of the outdoor fan 33 is performed. Thus, the outdoor fan 33 can be reliably prevented from being damaged by snow or ice.
Furthermore, since the outdoor fan 33 is rotationally driven when the heater 42 generates heat, overheating by the heater 42 is prevented. That is, a part of the heat generated from the heater 42 is taken away by the outdoor air flow flowing in the vicinity of the heater 42 caused by the outdoor fan 33, and thus overheating is prevented.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
The basic configuration of the air conditioner of the present embodiment is the same as that of the first embodiment, but differs from the first embodiment in the content of the snow prevention control from the power failure to the first activation. Therefore, in this embodiment, only the content of the snow prevention control at the time of the first start after a power failure is demonstrated using FIG. 11, and description of other components etc. is abbreviate | omitted.
FIG. 11 is a block diagram illustrating a configuration of a control unit in the air conditioner of the present embodiment.
In addition, the same code | symbol is attached | subjected to the component same as 1st Embodiment, and the description is abbreviate | omitted.

As shown in FIG. 11, the temperature of the outdoor air measured by the outside air temperature sensor 61 is input to the control unit 343 of the air conditioner 310 of the present embodiment. On the other hand, a control signal for controlling the rotational speed of the outdoor fan 33 is output from the control unit 343 to the motor 33b of the outdoor fan 33, and a control signal for controlling heat generation in the heater 42 is output from the control unit 243 to the heater 42. Yes.
Control of outdoor fan 33 and heater 42 by control unit 343 will be described later.

  Next, the operation of the air conditioner 310 having the above configuration will be described. Since the operation of the air conditioner 310 during the heating operation and the cooling operation and the snow prevention control during the heating operation stop are the same as those in the first embodiment, the description thereof is omitted.

Here, the snow prevention control from the power failure to the first activation, which is a feature of the present embodiment, will be described.
When detecting the stop (power failure) of the power supply to the air conditioner 310, the control unit 343 starts the snow prevention control until the air conditioner 310 is activated for the first time after the supply of power is resumed.
In the snow prevention control performed at this time, the operation of the outdoor fan 33 and the heat generation of the heater 42 are continuously performed.

  According to the above configuration, the snow and ice accumulated in the outdoor unit 30 and the like while the power supply is stopped can be removed by the first start after the power failure in the air conditioner 310. The fan 33 can be reliably prevented from being damaged.

  As a case where the power supply to the air conditioner 310 is stopped, the air conditioner installed in a store, school, or office has a long period when the air conditioner is not used, such as nighttime or long vacation. be able to.

  Furthermore, it is desirable that the snow prevention control in this embodiment is performed by dividing a predetermined period. As a predetermined period, the period which can melt the snow blown overnight, for example, 6 hours can be mentioned.

10, 110, 210 Air conditioner 20 Indoor unit 30 Outdoor unit 31 Housing 32 Outdoor heat exchanger 33 Outdoor fan (outdoor air blower)
41 Drain pan (drainage)
42 Heater (heating unit)
43, 143, 243 Control unit 163 Temperature sensor (temperature measurement unit)

Claims (8)

An outdoor unit that constitutes an air conditioner together with an indoor unit,
An outdoor air blower that takes in outdoor air from the outside of the housing and exchanges heat in the outdoor heat exchanger;
A heating unit that is disposed below the outdoor heat exchanger and the outdoor air blowing unit and heats a drainage unit that discharges water inside the housing to the outside; and
A control unit for controlling the operation of the outdoor ventilation unit and the heat generation of the heating unit;
Is provided,
The outdoor air blower includes an outdoor fan that blows the outdoor air by being driven to rotate,
When the heating operation of the air conditioner is stopped, the control unit performs intermittent operation of the outdoor air blowing unit,
Furthermore, the heating by the heating unit is started from the time when the rotational drive of the outdoor fan is stopped ,
The controller is
When rotation of the outdoor fan is stopped, the rotation of the outdoor fan due to the flow of the outdoor air is detected,
Outdoor unit wherein the outdoor fan is in the case which is driven to rotate, characterized Rukoto rotates the outdoor fan at a rotational speed based on the rotation speed detected. An outdoor unit that constitutes an air conditioner together with an indoor unit,
An outdoor air blower that takes in outdoor air from the outside of the housing and exchanges heat in the outdoor heat exchanger;
A heating unit that is disposed below the outdoor heat exchanger and the outdoor air blowing unit and heats a drainage unit that discharges water inside the housing to the outside; and
A control unit for controlling the operation of the outdoor ventilation unit and the heat generation of the heating unit;
Is provided,
The outdoor air blower includes an outdoor fan that blows the outdoor air by being driven to rotate,
When the heating operation of the air conditioner is stopped, the control unit performs intermittent operation of the outdoor air blowing unit,
Furthermore, heating by the heating unit is started from the time when the rotational driving of the outdoor fan is started, and heating by the heating unit is ended when the rotational driving of the outdoor fan is stopped ,
The controller is
When rotation of the outdoor fan is stopped, the rotation of the outdoor fan due to the flow of the outdoor air is detected,
Outdoor unit wherein the outdoor fan is in the case which is driven to rotate, characterized Rukoto rotates the outdoor fan at a rotational speed based on the rotation speed detected.   An outdoor unit that constitutes an air conditioner together with an indoor unit,
  An outdoor air blower that takes in outdoor air from the outside of the housing and exchanges heat in the outdoor heat exchanger;
  A heating unit that is disposed below the outdoor heat exchanger and the outdoor air blowing unit and heats a drainage unit that discharges water inside the housing to the outside; and
  A control unit for controlling the operation of the outdoor ventilation unit and the heat generation of the heating unit;
Is provided,
  When the heating operation of the air conditioner is stopped, the control unit performs intermittent operation of the outdoor air blowing unit,
  Furthermore, the heating by the heating unit is started from the time when the rotational drive of the outdoor fan is started,
  When power is supplied after power supply to the air conditioner is stopped, the control unit operates the outdoor air blowing unit for a predetermined period longer than the intermittent operation period, and the heating An outdoor unit that is heated by a section.   An outdoor unit that constitutes an air conditioner together with an indoor unit,
  An outdoor air blower that takes in outdoor air from the outside of the housing and exchanges heat in the outdoor heat exchanger;
  A heating unit that is disposed below the outdoor heat exchanger and the outdoor air blowing unit and heats a drainage unit that discharges water inside the housing to the outside; and
  A control unit for controlling the operation of the outdoor ventilation unit and the heat generation of the heating unit;
Is provided,
  When the heating operation of the air conditioner is stopped, the control unit performs intermittent operation of the outdoor air blowing unit,
  Furthermore, heating by the heating unit is started from the time when the rotational driving of the outdoor fan is started, and heating by the heating unit is ended when the rotational driving of the outdoor fan is stopped,
  When power is supplied after power supply to the air conditioner is stopped, the control unit operates the outdoor air blowing unit for a predetermined period longer than the intermittent operation period, and the heating An outdoor unit that is heated by a section. The outdoor unit according to any one of claims 1 to 4 , wherein a heating period by the heating unit is set in advance according to a capacity of the heating unit. A temperature measuring unit for measuring the temperature of at least one of the housing, the outdoor air blowing unit, and the drainage unit;
The control unit makes the next operation period by the outdoor air blowing unit longer than the previous operation period when the measurement value of the temperature measurement unit is less than a predetermined value at the end of heating by the heating unit. The outdoor unit according to any one of claims 1 to 4 . A temperature measuring unit for measuring the temperature of at least one of the housing, the outdoor air blowing unit, and the drainage unit;
Wherein, when the measured value of the temperature measuring section during heating by the heating unit starts to rise, according to any one of claims 1 to 4, characterized in that to terminate the heating by the heating unit Outdoor unit. Indoor unit,
An outdoor unit according to any one of claims 1 to 7,
Is provided with an air conditioner.

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