JP2011247525A - Refrigerating device - Google Patents

Abstract

An air pressure sensor of a differential pressure detection type has two air detection ends, so that the detection end is blocked by foreign matters such as frost, snow, ice, and dust, so that accurate pressure detection cannot be performed. There was a problem of becoming.
An outdoor unit 10, a partition plate 33 that divides the interior of the outdoor unit 10 into an air passage 30 and a machine room 31, an outdoor heat exchanger 3 provided on the air passage 30 side, and an outdoor heat exchanger 3 are provided. The outdoor fan 12 that allows air to pass through, the electrical box 32 that is disposed in the outdoor unit 10 and above the partition plate 33 so as to straddle the air passage 30 and the machine room 31, and before and after passing through the outdoor heat exchanger 3. An air differential pressure sensor that senses the differential pressure of the air. Of the two detection ends of the air differential pressure sensor, the air differential pressure sensor measurement side detection end 15a, which is one of the detection ends, is connected to the air passage 30 and the other end. The air differential pressure sensor reference side detection end 15 b is provided in the machine room 31.
[Selection] Figure 2

Description

  The present invention relates to an outdoor unit structure of a heat pump refrigeration apparatus.

  Conventionally, this type of refrigeration apparatus, for example, an air conditioner, uses a refrigerant temperature of an outdoor heat exchanger in order to detect frost formation due to a decrease in the temperature of the outdoor heat exchanger during heating operation under a low outdoor temperature. A refrigerant temperature sensor for detecting, and an air pressure sensor for detecting a ventilation resistance of air passing through the outdoor heat exchanger that increases with the growth of frost, and the refrigerant temperature of the outdoor heat exchanger is equal to or lower than a predetermined value, and There has been proposed a device provided with frost determination means for determining that the outdoor heat exchanger is frosted when the static pressure of the air after passing through the outdoor heat exchanger is larger than a predetermined value (for example, Patent Documents). 1).

  In addition, this type of outdoor unit of an air conditioner includes a partition plate that divides the interior into an air passage and a machine room, and compresses the air heat exchanger and the outdoor fan in the divided air passage side space and the machine room side. In general, a refrigeration cycle component such as a machine is arranged, and an electrical box containing a control board on which an electrical control component is mounted is arranged above the partition plate so as to straddle the air passage and the machine room (for example, a patent) Reference 2).

  Furthermore, in recent years, low-cost and high-performance pressure sensors have been actively developed, and it has been expensive to install in general-purpose air conditioners. It is out. These low-cost pressure sensors are generally of a differential pressure detection type.

  FIG. 6 shows a conventional air conditioner described in Patent Document 1. In FIG. In FIG. 6, the refrigerant circuit formed by connecting the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the pressure reducing device 4, and the indoor heat exchanger 5 in an annular manner changes the refrigerant circulation direction by the switching operation of the four-way valve 2. The cooling operation and the heating operation can be selected by reversibly changing. During the cooling operation, the refrigerant circulates in a solid arrow direction, and during the heating operation, the refrigerant circulates in a broken arrow direction. During the heating operation, the outdoor fan 12 is operated so that the outside air passes through the outdoor heat exchanger 3 and exchanges heat with the refrigerant in the refrigerant circuit to act as an evaporator to absorb heat from the outside air and perform the heating operation. .

  When the outside air temperature decreases, frost forms on the surface of the outdoor heat exchanger 3, and when the frost grows, air circulation is hindered, and heat exchange is hindered so that frost grows further. It is necessary to perform defrosting operation to interrupt frost and remove frost. In order to determine whether or not the outdoor heat exchanger 3 is frosted, the refrigerant temperature sensor 13 and the air pressure sensor 16 are provided, the refrigerant temperature of the outdoor heat exchanger 3 is equal to or lower than a predetermined value, and the outdoor heat exchanger 3 is When the static pressure of the air after passing is larger than a predetermined value, the frosting determination means 22 is provided that determines that the outdoor heat exchanger 3 is frosted.

  FIG. 7 shows a conventional air conditioner described in Patent Document 2. As shown in FIG. In FIG. 7, the interior of the outdoor unit 10 is divided into an air passage 30 and a machine room 31 by a partition plate 33. The outdoor heat exchanger 3 is disposed in the air passage 30 and air is passed through the outdoor heat exchanger 3. The outdoor fan 12 is arranged. In the machine room 31, the compressor 1 and other refrigeration cycle parts (not shown) are arranged. The partition plate 33 has a configuration in which an upper end portion is notched, and an electrical box 32 is disposed in the notch portion so as to straddle the air passage 30 and the machine room 31.

JP 60-218551 A Japanese Patent No. 3535843

  However, in the conventional configuration, in order to accurately determine frost formation, an air pressure sensor for detecting the static pressure of the air that has passed through the outdoor heat exchanger is employed, so that it is a relatively inexpensive differential pressure detection type. Therefore, since the differential pressure detection type air pressure sensor has two detection ends for detecting the air pressure, compared with the conventional air pressure sensor having one detection end. In addition, there has been a problem that the risk that the detection end is blocked by foreign matters such as frost, snow, ice, and dust and the state where accurate differential pressure detection cannot be performed is doubled.

  The present invention solves the above-described conventional problems, and in accurately detecting frost formation using a relatively inexpensive differential pressure detection type air pressure sensor, the detection end of the differential pressure detection type air pressure sensor is An object of the present invention is to provide a refrigeration apparatus with a low risk of being blocked by a foreign object.

  In order to solve the above-described conventional problems, the refrigeration apparatus of the present invention includes an outdoor unit, a partition plate that divides the interior of the outdoor unit into an air passage and a machine room, an outdoor heat exchanger provided in the air passage, An outdoor fan that allows air to pass through the outdoor heat exchanger, and an air differential pressure sensor in which one of the two detection ends is provided in the air passage and the other is provided in the machine room.

  As a result, the detection end of the air differential pressure sensor is less likely to come into contact with foreign matter such as frost, snow, ice, and dust, and the refrigeration apparatus is less likely to be in a state where the detection end is blocked and cannot accurately detect the differential pressure. Can be provided.

  In the refrigeration apparatus of the present invention, when accurately detecting frost formation using a relatively inexpensive differential pressure detection type air pressure sensor, the detection end of the differential pressure detection type air pressure sensor (air differential pressure sensor) is a foreign object. Can reduce the risk of being blocked.

Configuration diagram of refrigeration cycle and control block according to Embodiment 1 of the present invention The block diagram of the outdoor unit in Embodiment 1 of this invention Temporal change graph of temperature and differential pressure in Embodiment 1 of the present invention Control flowchart according to Embodiment 1 of the present invention The block diagram of the outdoor unit in Embodiment 2 of this invention Configuration diagram of refrigeration cycle and control block of conventional air conditioner Configuration diagram of outdoor unit of conventional air conditioner

  The first invention includes an outdoor unit, a partition plate that divides the interior of the outdoor unit into an air passage and a machine room, an outdoor heat exchanger provided in the air passage, and an outdoor fan that allows air to pass through the outdoor heat exchanger. And an air differential pressure sensor in which one of the two detection ends is provided in the air passage and the other is provided in the machine room, so that a relatively inexpensive differential pressure detection type air pressure sensor (air differential pressure) is provided. In the accurate frost determination using the sensor, the risk that the detection end of the air differential pressure sensor is blocked by foreign matter can be reduced.

The second invention includes an outdoor unit, a partition plate that divides the interior of the outdoor unit into an air passage and a machine room, an outdoor heat exchanger provided in the air passage, and an outdoor fan that allows air to pass through the outdoor heat exchanger. And an electrical box disposed above the partition plate so as to straddle the air passage and the machine room, and an air differential pressure sensor in which one of the two detection ends is provided in the air passage and the other is provided in the electrical box The risk of the detection end of the air differential pressure sensor being blocked by foreign matter can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a refrigeration cycle and a control block according to the first embodiment of the present invention.

  In FIG. 1, the refrigeration apparatus of the present embodiment is an air conditioner in which an outdoor unit 10 and an indoor unit 11 are connected by piping. The outdoor unit 10 includes a compressor 1 that compresses the refrigerant, a four-way valve 2 that switches the flow direction of the refrigerant, an outdoor heat exchanger 3 that exchanges heat between the refrigerant and the outside air, a decompression device 4 that expands the refrigerant, and an outdoor unit. An outdoor fan 12 that blows outside air to the heat exchanger 3, an outside air temperature sensor 14 that detects the air temperature around the outdoor unit 10, and the like are provided, and the indoor unit 11 heats between the refrigerant and the indoor air. An indoor heat exchanger 5 that performs exchange is provided.

  Further, in order to determine whether or not the outdoor heat exchanger 3 has been frosted, a refrigerant temperature sensor 13, an air differential pressure sensor 15, an air differential pressure detection means 20, a storage means 21, and a frost determination determination means 22 are provided. Yes. The refrigerant temperature sensor 13 is provided on a refrigerant pipe constituting the outdoor heat exchanger 3 in order to detect the temperature of the outdoor heat exchanger 3. The air differential pressure sensor 15 is a sensor that detects the differential pressure of the air before and after passing through the outdoor heat exchanger 3, and the differential pressure sensor measurement side detection end 15 a that measures the pressure of the air at the location to be measured, And an air differential pressure sensor reference side detection end 15b for measuring the pressure of air serving as a pressure reference.

  The air differential pressure detection means 20 takes the output value of the air differential pressure sensor 15 as an input value, appropriately calculates and converts the input value, and outputs a detected value of the air differential pressure. The storage means 21 is a memory that temporarily stores the output value of the air differential pressure detection means 20. The frost formation determination unit 22 determines whether or not the outdoor heat exchanger 3 is frosted based on the value stored in the storage unit 21 or the output value of the air differential pressure detection unit 20. . The air differential pressure detection means 20, the storage means 21, and the frost formation determination means 22 are provided as part of a control board (not shown) together with control means for controlling the rotation speed of the compressor 1 and the rotation speed of the outdoor fan 12. It has been.

  The compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the pressure reducing device 4, and the indoor heat exchanger 5 are connected in an annular manner by refrigerant piping to form a refrigerant circuit, and the refrigerant circulation direction is changed by switching operation of the four-way valve 2. The cooling operation and the heating operation can be selected by reversibly changing. During the cooling operation, the refrigerant circulates in a solid arrow direction, and during the heating operation, the refrigerant circulates in a broken arrow direction. During the heating operation, the outdoor fan 12 is operated so that the outside air passes through the outdoor heat exchanger 3, exchanges heat with the refrigerant in the refrigerant circuit, and acts as an evaporator to absorb heat from the outside air. Heating operation is performed by radiating heat with the exchanger 5. When the outside air temperature decreases during the heating operation, frost is generated on the surface of the outdoor heat exchanger 3, and when the frost grows, air circulation is hindered, and heat exchange is hindered so that frost further grows. Therefore, it is necessary to interrupt the heating and perform a defrosting operation to remove frost.

FIG. 2 shows a configuration diagram of the outdoor unit according to the first embodiment of the present invention. In FIG. 2, the interior of the outdoor unit 10 is divided into an air passage 30 and a machine room 31 by a partition plate 33. The outdoor heat exchanger 3 is disposed in the air passage 30 and air is passed through the outdoor heat exchanger 3. The outdoor fan 12 is arranged. In the machine room 31, the compressor 1 and other refrigeration cycle parts (not shown) are arranged. The upper end portion of the partition plate 33 is notched, and the electrical equipment box 32 is arranged so as to straddle the air passage 30 and the machine room 31 in this notch portion. A control board on which electrical control components are mounted is accommodated in the electrical box 32. An air differential pressure sensor measurement side detection end 15a is disposed on the air passage 30 side below the electrical box 32, and an air differential pressure sensor reference side detection end 15b is disposed on the machine room 31 side.

  FIG. 3 shows a time-dependent graph of the temperature of the outdoor heat exchanger 3 and the differential pressure of air before and after passing through the outdoor heat exchanger 3, and FIG. 4 shows a control flowchart.

  3 and 4, details of the frost determination method using the configuration including the refrigerant temperature sensor 13, the air differential pressure sensor 15, the air differential pressure detection means 20, the storage means 21, and the frost determination means 22 of FIG. 1 will be described. To do. Until time 1 shown in FIG. 3 is reached, the air differential pressure sensor 15 and the air differential pressure detection means 20 before and after passing the outdoor heat exchanger 3 in S2 are maintained while continuing the heating operation of S1 shown in FIG. Detect air differential pressure. In S3, the refrigerant temperature sensor 13 determines whether the temperature of the outdoor heat exchanger 3 is a predetermined value, for example, less than 0 ° C., and the value stored in the storage means 21 in S4. The loop of updating and returning to S2 is repeated.

  After that, after Time 1 in FIG. 3, that is, after the time when the temperature of the outdoor heat exchanger 3 detected by the refrigerant temperature sensor 13 becomes a predetermined value, for example, less than 0 ° C., The value stored in the storage means 21 in S4 is not updated, and the outdoor heat exchange is performed in a state in which the temperature of the outdoor heat exchanger 3 is maintained at a predetermined value, for example, a value when the temperature is less than 0 ° C. The pressure difference between the air before and after passing through the vessel 3 is compared with the value held in the storage means 21 to determine whether or not the predetermined value is exceeded. That is, the loop of S2-> S3-> S5-> S2 is repeated. Thereafter, when Time 2 in FIG. 3 is reached, if the differential pressure of the air before and after passing through the outdoor heat exchanger 3 exceeds a value obtained by adding a predetermined value to the value held in the storage means 21, S5 in FIG. Is satisfied, that is, it is determined that the outdoor heat exchanger 3 is sufficiently frosted, and the defrosting operation is started.

  As described above, in the present embodiment, in order to determine whether or not the outdoor heat exchanger 3 has been frosted, the refrigerant temperature sensor 13, the air differential pressure sensor 15, the air differential pressure detection means 20, and the storage means 21. The outdoor heat exchanger detected when the frost determination means 22 is at a temperature that is a refrigerant temperature at which the outdoor heat exchanger 3 is not frosted, for example, 0 ° C. or more, is provided with the frost determination means 22. By using the differential pressure before and after 3 as a reference, the outdoor heat exchanger 3 is frosted and the frost formation is determined by comparing with the differential pressure of the outdoor heat exchanger 3 when the refrigerant temperature is less than 0 ° C. Even when the outdoor heat exchanger 3 is clogged with dust or the like due to a change, or when there is a difference in ventilation resistance depending on the installation condition of the air conditioner, it is possible to accurately determine frost formation. Thereby, the defrosting operation can be performed at an appropriate time, and the operation efficiency of the refrigeration apparatus can be improved.

  Furthermore, in the present embodiment, the air differential pressure sensor measurement side detection end 15a and the air differential pressure sensor reference side detection end 15b are not directly exposed to the outside environment in a form housed in the outdoor unit 10, The risk of being blocked by contact with foreign matters such as snow, ice and dust can be greatly reduced. Thereby, the defrosting operation can be performed at an appropriate time, and the operation efficiency of the refrigeration apparatus can be improved.

  The main body of the air differential pressure sensor 15 is provided in the electrical box 32, and only the air differential pressure sensor measurement side detection end 15a is disposed in the air passage 30 and only the air differential pressure sensor reference side detection end 15b is disposed in the machine room 31. It is desirable to reduce the size of the air differential pressure sensor 15 and the electrical box 32.

Moreover, in this Embodiment, the frost determination means 22 is provided with the refrigerant | coolant temperature sensor 13, the air differential pressure detection means 20, and the memory | storage means 21, and determines whether it has formed frost in consideration of those outputs. For example, the output value of the outside air temperature sensor 14 may be used instead of the output value of the refrigerant temperature sensor 13. Furthermore, it is good also as what determines whether the frost formation determination means 22 is frosting only from the output of the air differential pressure sensor 15. FIG.

(Embodiment 2)
FIG. 5 shows a configuration diagram of an outdoor unit according to the second embodiment of the present invention.

  In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The difference of the present embodiment from the first embodiment is that the air differential pressure sensor reference side detection end 15 b is disposed inside the electrical box 32. In addition, the air differential pressure sensor measurement side detection end 15a is arranged on the air passage 30 side below the electrical box 32 as in the configuration of the first embodiment.

  With this configuration, the air differential pressure sensor measurement side detection end 15a and the air differential pressure sensor reference side detection end 15b are housed in the outdoor unit 10 and are not directly exposed to the outside environment, so that frost, snow, ice The risk of being blocked by contact with foreign matter such as dust can be greatly reduced. Thereby, the defrosting operation can be performed at an appropriate time, and the operation efficiency of the refrigeration apparatus can be improved. Furthermore, since the air differential pressure sensor reference side detection end 15b is disposed inside the electrical box 32, the air differential pressure sensor 15 and the electrical box 32 can be reduced in size.

  The main body of the air differential pressure sensor 15 is provided in the electrical box 32, and the air differential pressure sensor 15 and the electrical box 32 are more compact if only the air differential pressure sensor measurement side detection end 15a is disposed in the air passage 30. It is desirable for

  As described above, the refrigeration apparatus according to the present invention reduces the risk that the detection end detection end of the air differential pressure sensor is blocked and cannot accurately detect differential pressure, and can accurately detect frost formation. It can also be applied to household and commercial air conditioners, heat pump water heaters, large refrigeration equipment, etc. that require frosting and defrosting as the ambient temperature decreases.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Pressure reducing device 5 Indoor heat exchanger 10 Outdoor unit 11 Indoor unit 12 Outdoor fan 13 Refrigerant temperature sensor 14 Outdoor temperature sensor 15 Air differential pressure sensor 15a Air differential pressure sensor measurement side detection end 15b Air differential pressure sensor reference side detection end 16 Air pressure sensor 20 Air differential pressure detection means 21 Storage means 22 Frosting determination means 30 Air passage 31 Machine room 32 Electrical box 33 Partition plate

Claims (2)

An outdoor unit, a partition plate that divides the interior of the outdoor unit into an air passage and a machine room, an outdoor heat exchanger provided in the air passage, an outdoor fan that allows air to pass through the outdoor heat exchanger, and A refrigeration apparatus comprising an air differential pressure sensor in which one of two detection ends is provided in an air passage and the other is provided in the machine room. An outdoor unit, a partition plate that divides the interior of the outdoor unit into an air passage and a machine room, an outdoor heat exchanger provided in the air passage, an outdoor fan that allows air to pass through the outdoor heat exchanger, and An electrical box provided on the upper part of the partition plate so as to straddle the air passage and the machine room, and an air difference in which one of two detection ends is provided in the air passage and the other is provided in the electrical box. A refrigeration apparatus comprising a pressure sensor.