JP4365378B2 - Defrosting operation control device and defrosting operation control method - Google Patents

Description

  The present invention relates to a defrosting operation control device and a defrosting operation control method for a refrigeration, refrigeration, and air conditioner, and more particularly to a defrosting operation control device and a defrosting operation control method for an evaporator that is a heat exchanger.

As an example of a conventional defrosting operation control device, the outside air frost coefficient derived from the outside air temperature state, the inside room frost coefficient derived from the inside cooling state, the state factor of the solenoid valve, and the performance determined for each case The amount of frost formation per unit time is calculated by multiplying by the coefficient, and the defrosting of the cooler is performed when the cumulative frost amount obtained by integrating the frost formation amount reaches a predetermined value. There is known a method of performing (see Patent Document 1).
Japanese Patent Laid-Open No. 5-118732 (FIG. 2)

  However, the conventional defrosting time determination method does not take into account the frosting state of the evaporator 10 that is a heat exchanger, so the high-temperature and high-humidity outside air that flows into the storage when the door is opened and closed and the low-temperature and low-humidity storage The internal air is directly mixed and the moisture in the air sucked into the evaporator 10 is frozen to become snowy air, so that low density snow directly adheres to the evaporator 10, and the moisture in the normal air is evaporated. It was not effective for a phenomenon in which the air passage of the evaporator 10 was blocked earlier than frosting condensed and frozen on the surface. For this reason, the defrosting time cannot be properly detected, and there is a problem that defrosting is not started even if the air passage of the evaporator 10 is blocked by snow or frost.

  The present invention has been made to solve the above-described problems, and reliably detects a frosting portion on the evaporator 10 that is a heat exchanger, and an appropriate defrosting time according to the frosting portion. An object of the present invention is to provide a defrosting operation control device and a defrosting operation control method capable of starting defrosting.

The defrosting operation control device according to the present invention includes means for measuring the air suction side temperature of a heat exchanger used on the cooling side of a refrigerator or an air conditioner, and the temperature and humidity outside the chamber to be cooled (hereinafter referred to as measurement). And a means for determining the frost formation part of the heat exchanger based on the result measured by the measuring means and determining the defrosting start time . Corresponds to frost formation on the first part of the heat exchanger when the straight line connecting the temperature and humidity and the temperature and humidity on the air suction side of the heat exchanger or the temperature and humidity in the cooling target room enters the region exceeding the saturation line. It is classified as the first frost type .

  This invention specifies the frost formation part to the evaporator 10 to the evaporator 10 based on the external temperature humidity of the evaporator 10, and the internal temperature condition, classifies and determines a different frost formation part as a frost formation type, and forms frost Since the defrosting operation is started at the defrosting time corresponding to the mold, the defrosting operation at the optimal time is possible from the viewpoint of energy saving.

Embodiment 1 FIG.
First, the contents of the defrosting start timing determining means 50 according to the first embodiment of the present invention will be described, and the frosting of the evaporator 10 will be determined later by the outside air temperature humidity and the air suction side temperature in the cabinet, which are the characteristics of the present invention. A defrosting control correspondence method when a part is classified as a frosting type will be described.

  The structure of the defrosting start time determination means 50 is demonstrated using FIGS. 1-4. FIG. 1 is an overall configuration diagram of a cooling system according to Embodiment 1 of the present invention, which includes a refrigeration warehouse 1 and a refrigeration apparatus. The freezer warehouse 1 is constituted by a heat insulating wall, and has a structure that suppresses heat penetration from outside as much as possible. Moreover, the freezer warehouse 1 is provided with a door 6 so that a person can go in and out and a object to be cooled can be carried in and out. In addition to the door type that unlocks and opens by hand, there are also automatic opening and closing types. A cooling device 2 is provided inside the freezer warehouse 1 (hereinafter referred to as “inside”), an outdoor unit 3 is provided outside the freezer warehouse 1 (hereinafter referred to as “outside”), and a controller 4 for controlling these is provided. The cooling device 2 and the outdoor unit 3 are connected by a refrigerant pipe 7. The cooling device 2 cools the inside of the cabinet, and the outdoor unit 3 uses heat exchange to absorb the heat in the cabinet that the cooling device 2 has absorbed by heat exchange. Throw away outside. The cooling device 2, the outdoor unit 3, and the refrigerant pipe 7 constitute a refrigeration device. The cooling device 2 may be a type that is suspended from the ceiling, or a type that is embedded and fixed in a ceiling, a side wall, or the like. The outdoor unit 3 may be a type installed on the ceiling or a type installed outdoors. The controller 4 is a control device that adjusts the internal temperature or adjusts the timing of the defrosting operation control, and can set the internal temperature and the like. The function of the controller 4 may be included in a microcomputer (not shown) in which the cooling device 2 or the outdoor unit 3 is built.

  FIG. 2 shows a cross-sectional view of the cooling device 2 viewed from the lateral direction. The cooling device 2 includes an evaporator 10 made of metal fins and pipes for cooling air, a blower fan 11 that blows air to the evaporator 10, a motor 12 that drives the blower fan 11, and the evaporator 10 and It comprises a heater 13 for heating the drain pan 15 and a drain pipe 14 for discharging water defrosted during the defrosting operation. The cooling device 2 includes an evaporation temperature sensor 16 that measures a refrigerant evaporation temperature of an evaporator 10 that is a heat exchanger that cools air, an air suction side temperature sensor 17 that measures an air suction side temperature, and an air blowing side. An air outlet side temperature sensor 18 for measuring the temperature is provided, and the temperature of each part can be measured. In addition, the heater 13 attached to the evaporator 10 is in close contact with the fins or pipes of the evaporator 10 and can efficiently melt the frost attached to the fins and pipes of the evaporator 10. Yes.

  FIG. 3 is a diagram illustrating a refrigeration cycle of the refrigeration apparatus. A refrigerant is sealed in the refrigeration apparatus, and the compressor 20, the condenser 21, the expansion valve 22, and the evaporator 10 are sequentially connected by piping. In addition to the evaporation temperature sensor 16, the refrigeration apparatus includes an expansion valve pre-pressure sensor 31 that measures refrigerant pressure, a compressor suction pressure sensor 34, an evaporator outlet temperature sensor 32 that measures temperature, and a compressor suction temperature sensor 33. These sensors are provided, and the operation state of the refrigeration cycle can be grasped. The refrigerant used in the refrigeration apparatus may be a single refrigerant such as R22 or a mixed refrigerant composed of a plurality of refrigerants such as R404A.

  FIG. 4 is a configuration diagram of the controller 4 shown in FIGS. Next, the controller 4 will be described with reference to FIG. The controller 4 compares the calculation means 41 for calculating the information obtained from each temperature sensor and each pressure sensor, the storage means 42 for storing various calculation values and predetermined values, and the magnitude of these values. Comparison means 43, determination means 44 for determining the defrosting start time and end time, input / output means 45 for performing screen display output and sound output such as user input and calculation results, and on / off of the compressor motor And a control means 46 for controlling the rotational speed. The defrosting time determining means 50 for determining the optimum defrosting time is composed of the calculating means 41, the storage means 42, the comparing means 43, the determining means 44, and the input / output means 45.

  Specifically, the controller 4 includes a central processing unit (CPU) that controls the compressor 20 of the refrigeration apparatus, a memory that stores programs and data, an external input / output device such as a touch panel and a keyboard, a display, and the like. And a microcomputer provided with a display unit. Of these, the CPU 41 and a predetermined program constitute the calculation means 41, the comparison means 43, and the determination means 44. Further, the memory means 42 is constituted by a memory, the input / output means 45 is constituted by a display unit such as a keyboard, a touch panel and a display, and the control means 46 is constituted by a relay, a power transistor and the like. In addition, it is possible to easily change the set temperature of the freezer warehouse 1 using the input / output means 45. In addition, the determination result and calculation content of the defrosting time, the value of each sensor may be configured to be transmitted and received to a remote location such as a service center, for example, a location away from the installation device via a wired or wireless signal, In this case, it is possible to monitor the operating state, operate the device, change the set value, etc. from a remote location.

  Next, the refrigeration cycle operation of the refrigeration apparatus will be described. The high-temperature and high-pressure refrigerant discharged from the compressor 20 exchanges heat with outdoor air in the condenser 21, and the refrigerant is condensed and liquefied. The refrigerant that has been decompressed by the expansion valve 22 and is in a low-pressure and low-temperature two-phase state exchanges heat with the air in the freezer warehouse 1 in the evaporator 10, evaporates and gasifies the refrigerant, and cools the air in the warehouse. The low-pressure gaseous refrigerant exiting the evaporator 10 is repeatedly sucked into the compressor 20 and compressed, and is discharged again as a high-temperature and high-pressure refrigerant. Thereby, the air in the freezer warehouse 1 is cooled, and the inside of the warehouse can be kept at a low temperature.

  By the above operation, cooling by the cooling device 2 is performed in the freezer warehouse 1. The temperature in the freezer warehouse 1 needs to be kept constant, and a method for adjusting the temperature will be described. When the compressor 20 is a fixed frequency operation system (non-inverter), the temperature is adjusted by an on / off operation of the compressor 20 according to a command from the control means 46. The temperature of the freezer warehouse 1 is monitored by the internal temperature sensor 5, and when the internal temperature falls below a predetermined temperature, the compressor 20 is turned off. When the internal temperature rises, the compressor 20 is turned on again and the cooling operation is started. The ON / OFF temperature difference and the internal set temperature can be set from the input / output means 45 of the controller 4.

  Moreover, when the compressor 20 is an inverter system, it is possible to change the operating frequency of the compressor 20 by a command from the control means 46 of FIG. In the case of the inverter system, the operation frequency of the compressor 20 is controlled so that the evaporation temperature is constant, and the cooling capacity is excessive even if the compressor frequency is operated at the lower limit value, and the temperature in the freezer warehouse 1 is set. When the temperature falls below the temperature, the compressor 20 is turned off. When the internal temperature rises, the compressor 20 is turned on again to start the cooling operation, whereby the internal temperature of the freezer warehouse 1 can be kept constant.

  Next, a defrosting operation method performed when the evaporator 10 has a lot of frost will be described. If the evaporator 10 is cooled for a long time under a condition where the temperature of the evaporator 10 is below freezing, moisture in the air freezes and adheres to the evaporator 10 and closes the air passage to cause air path pressure loss, Air becomes a heat resistance when heat exchange is performed, and heat transfer performance is reduced. When the amount of frost formation is excessive, the cooling capacity is insufficient and the inside of the freezer warehouse 1 cannot be maintained at the set temperature. Therefore, a defrosting operation for melting and removing the frost attached to the evaporator 10 is performed to return the cooling capacity to a state where the original performance can be exhibited. The frosting state on the evaporator 10 during the cooling operation is monitored by the defrosting time determining means 50, and the defrosting start command is controlled when the optimum defrosting time at which the energy consumption efficiency is maximum and the most energy saving is reached. Communicated to means 46. In the control means 46, the operation of the compressor 20 and the blower fan 11 is stopped, and the heater 13 which is a heat source for defrosting is turned on. The heater 13 heats the evaporator 10 and the drain pan 15, melts the attached frost to form a liquid drain water, and the drain water is discharged from the drain pipe 14 to the outside of the warehouse. Then, the defrosting completion timing at which the frost is completely melted is determined when the evaporation temperature sensor 16 reaches a predetermined temperature, the heater 13 is turned off, the operation of the compressor 20 and the blower fan 11 is restarted, and the cooling operation is performed again. Migrate to

  In addition, although the said defrost operation demonstrated the case of the heater heating system, it connects the refrigerant | coolant piping 7 so that the discharge gas of the compressor 20 may be directly returned to the evaporator 10, and flows hot gas, or the compressor 20's A four-way valve is provided in the discharge and suction pipes, and the refrigerant flowing in the evaporator 10 and the condenser 21 is reversed in direction, that is, by switching the four-way valve, the refrigerant discharged from the compressor 20 is expanded into the evaporator 10 and expanded. A configuration in which the defrosting operation is performed as a circuit configuration that circulates in the order of the valve 22 and the condenser 21 and returns to the compressor 20 may be used.

Next, the determination method of the defrosting time determination means 50 is demonstrated based on FIG.2, FIG5 and FIG.6. As shown in FIG. 2, in the cooling device 2, the evaporation temperature sensor 16 that measures the refrigerant evaporation temperature of the evaporator 10, the air suction side temperature sensor 17 that measures the air suction side temperature, and the air blowing side temperature are measured. The air blowing side temperature sensor 18 is provided, and the temperature of each part can be measured. The calculation means 41 calculates temperature efficiency by the following formula (1) based on these temperature information.
Temperature efficiency = (Air suction side temperature-Air blowing side temperature) / (Air suction side temperature-Evaporation temperature))
... Formula (1)
Here, / represents division.
The temperature efficiency is a parameter that represents the efficiency of heat exchange between the refrigerant and air in the evaporator 10, and is an effect of an increase in thermal resistance due to frost adhering to the heat transfer surface of the evaporator 10 during frost formation, and a change in air volume due to air passage blockage. This parameter takes into account the effects of both sides. When the air blowing side temperature is equal to the evaporation temperature, temperature efficiency = 1, and the efficiency is the highest. On the air diagram, if the air suction side temperature is AT, the evaporation temperature is ET, and the air blowing side temperature is To, the concept of temperature efficiency can be expressed as shown in FIG. If the dry-bulb temperature difference from AT to ET is 1 (100%), the temperature efficiency is Z (from equation (1)).

  The upper diagram in FIG. 5 is a graph showing the relationship between the frost formation amount and the temperature efficiency during the cooling device operation, and the horizontal axis represents the frost formation amount of the evaporator 10. In the figure, a range indicated by an arrow indicates a zone suitable as a temperature efficiency threshold candidate. In the figure, there are many portions where the temperature efficiency becomes zero. This is because the compressor 20 of the target refrigeration apparatus is a fixed frequency operation system, and therefore the compressor 20 when the internal temperature reaches the target temperature. This is because the thermo-off for turning off and the temperature adjustment control for turning on the compressor 20 again after the internal temperature rises above the set value are repeated. As can be seen from the figure, as the frosting amount of the evaporator 10 increases, the temperature efficiency gradually decreases.

  On the other hand, the lower diagram of FIG. 5 is a graph showing the relationship between the frost formation amount during the operation of the cooling device 2 and the temperature efficiency. The horizontal axis represents the frost formation amount and the vertical axis represents the timing of the horizontal axis value. Average input when the frost operation is started (Here, the input is power consumption or energy consumption, and the average input is one cycle of cooling defrosting of the refrigerator, that is, “total input during cooling operation + It is the figure showing how many% it increased by making the lower limit (in the case of energy saving most) of the "total input during defrost operation" into 100%. As can be seen from the figure, when the defrosting operation is started when the amount of frost formation is small, the average input is large because the energy related to defrosting, that is, the heater 13 with high power consumption is used wastefully. By the way, the average input reaches the lower limit peak. And if the amount of frost formation increases too much, since the cooling efficiency of the evaporator 10 will fall, in order to consume much compressor input, an average input will tend to increase. Based on the above, there is an optimal amount of frost when the defrosting operation is started, and energy saving operation with low average chiller input is possible by starting the defrosting operation at the optimal amount of frost I understand that

  In FIG. 5, the temperature efficiency when the average input of the refrigerator is the smallest frost amount is about 0.4. In the case of this refrigerator, the defrosting operation is performed when the temperature efficiency = 0.4. Once started, the refrigerator can be operated in the most energy-saving state. By setting an appropriate threshold value using temperature efficiency as a parameter and starting the defrosting operation when the temperature efficiency reaches the threshold value, it is possible to determine the optimum defrosting start time for energy saving. Thus, the refrigerator can be operated in an energy saving manner. In the lower diagram of FIG. 5, the range indicated by the arrow indicates that the zone is an appropriate zone with a small average input increase rate.

FIG. 7 is a flowchart showing the defrosting time determination process by the controller 4 when the optimum temperature efficiency is used. The flow of the defrosting start time determination based on the temperature efficiency will be described with reference to the flowchart of FIG.
First, in step ST1, it is determined whether the cooling operation after the initial installation or the defrosting operation has been started. This determination is made based on the on / off state of the compressor 20 and the heater 13 that are grasped by the controller 4, and it can be determined that the cooling operation has started if the heater 13 is off and the compressor 20 is on. When the cooling operation is started, the process proceeds to step ST2, and the controller 4 measures the operation data and calculates the temperature efficiency. In step ST3, it is determined whether the temperature efficiency is equal to or higher than a threshold value. If the temperature efficiency is equal to or higher than the threshold value, the process proceeds to step ST4, and the controller 4 instructs the start of the defrosting operation.

  The operation for determining the energy saving defrosting time is performed by the defrosting time determining means 50 of the controller 4. That is, the temperature efficiency is calculated from the information of each temperature sensor by the calculation means 41, and the calculation result is stored by the comparison means 43 and the storage means 42 in advance, or appropriately corrected and stored based on the actual operation characteristics of the actual machine. The temperature efficiency threshold value is compared, the determination unit 44 determines whether or not to start defrosting, and the input / output unit 45 outputs the determination result to the control unit 46. Under the control of the control means 46, control operations such as the compressor 20, the heater 13, and the motor 12 of the blower fan 11 are performed.

  Note that the temperature efficiency threshold is a function related to the temperature efficiency when the rotation speed of the blower fan 11 (hereinafter referred to as fan rotation speed) or the operation frequency of the compressor 20 can be changed. As described above, the set value may be changed, or the threshold value may be changed according to the model of the refrigerator. In addition, these threshold values may be changed in advance by storing the changed data in the storage means 42 such as a memory, or after the refrigerator is installed, the service person may change it from the input / output means 45 as necessary. Alternatively, the configuration may be changed from a remote location via a wired or wireless communication means.

  In addition, as a method of detecting the defrosting operation start timing, a method of starting the defrosting operation when the deviation from the initial state of the temperature efficiency is equal to or greater than a threshold value may be used. In this case, the initial temperature efficiency in the non-frosting state is initially learned after installation of the device, and the defrosting operation is started when the difference between the initial temperature efficiency and the current temperature efficiency is equal to or greater than the set threshold value. As described above, by performing initial learning according to the target device, it is possible to determine the optimum defrosting time according to individual differences of the evaporator 10.

The flow of the defrosting start time determination by the controller 4 when performing initial learning is shown in the flowchart of FIG.
In step ST1, the determination means 44 of the controller 4 determines whether the cooling operation after the initial installation or the defrosting operation has been started. When the cooling operation is started, the process proceeds to step ST2, and the calculation means 41 measures operation data and calculates temperature efficiency. In step ST3, the determination means 44 determines whether or not it has been learned. If it has not been learned, the process proceeds to step ST4, where operation data during normal stable operation in the initial stage of the cooling operation in which the evaporator 10 is not frosted. The reference state is learned using as the reference data. When learning is completed in step ST4, the determination in step ST3 is followed by a yes loop, that is, a loop after step ST5. In step ST5, the calculation means 41 calculates a difference dZ between the current temperature efficiency calculation value Z and the initial learning value Z0. In step ST6, the determination unit 44 determines whether or not dZ is equal to or greater than the set threshold value. If the value is larger than the threshold value, the process proceeds to step ST7, and the defrosting timing determination unit 50 instructs the control unit 46 to start the defrosting operation. To do. The control means 46 performs control operations of the compressor 20, the heater 13, the motor 12 of the blower fan 11, and the like according to a defrosting operation start command from the defrosting time determination means 50.

  As described above, according to the first embodiment, the temperature efficiency is calculated, and the optimum defrost start timing is determined using this temperature efficiency. Therefore, the determination accuracy of the defrost operation start timing is high, It is practical and the optimum defrosting time is reliably determined. Thereby, the defrost operation in the optimal time is attained, and energy saving can be aimed at.

Embodiment 2. FIG.
In the defrosting time determination method according to the first embodiment, the determination is performed using only a single parameter. However, with only a single parameter, it is not possible to follow the complicated operation of the actual machine that changes from moment to moment. There is a risk of causing a judgment. In the second embodiment, determination is made with a plurality of parameters so as to cope with such a case.
Next, a method for determining the defrosting start time based on a plurality of parameters obtained by adding other parameters to the temperature efficiency will be described. FIG. 9 is a diagram in which a fan rotation sensor 61 and a fan current sensor 62 are added to the cooling device 2 of FIG. The fan rotation sensor 61 is a sensor that detects the number of fan rotations of the blower fan 11, and is performed once every time the blower fan 11 rotates with light such as infrared light that is applied to a reflecting surface provided on a part of the blower fan 11. Since the light is reflected, the number of times of reflected light is counted to detect the number of rotations of the blower fan 11, or the number of rotations is detected by detecting the position of the rotor of the motor 12 using a Hall element. In addition, a method using magnetic flux may be used. The fan current sensor 62 detects the current of the blower fan 11 (hereinafter referred to as fan current), and measures the current value using CT (coil type) or the like. The fan rotation sensor 61 and the fan current sensor 62 can grasp the fan rotation speed of the blower fan 11 and the operating state of the fan current. The fan rotation speed and fan current of the blower fan 11 are parameters that change due to an increase in air path pressure loss when the evaporator 10 is blocked by frost. By using these parameters, the evaporator due to frost formation is used. It becomes possible to grasp the ten occlusion states. Note that changes in the evaporator 10 during frosting include changes in airway pressure loss and changes in heat transfer characteristics. Although the change in heat transfer characteristics cannot be detected by the fan rotation speed or fan current of the blower fan 11, this change in heat transfer characteristics can be one of the parameters for grasping the change during frost formation.

  One example of a method for processing a plurality of parameters is “Mahalanobis distance”, which is generally known. “Mahalanobis distance” is described in, for example, “Multivariate analysis that can be easily understood” (Non-Patent Document 1) issued by Tokyo Library on October 26, 1992, and is used in the field of multivariate analysis. It is a technique that is known. The Mahalanobis distance represents the normal state as an aggregate of a plurality of parameters, and represents the distance from the normal parameter aggregate. When the Mahalanobis distance is large, the distance is away from the normal state.

  First, the temperature efficiency was initially learned. However, if the temperature efficiency is initially learned as an assembly in a normal state by combining other parameters such as the air suction side temperature and the fan rotation speed of the blower fan 11 as well. It is also possible to determine the defrosting time using the Mahalanobis distance.

The flow of performing the optimum defrosting start time determination using the Mahalanobis distance will be described with reference to the flowchart of FIG. In the flowchart of FIG. 10, every time the cooling operation is started, the evaporator 10 in the initial operation stage learns the non-frosting state as a reference state, and thereafter the frosting state of the evaporator 10 in operation is determined. Monitoring is performed based on a change in Mahalanobis distance, and the control content is such that defrosting is started when the Mahalanobis distance exceeds a threshold.
In step ST1, it is determined whether or not the cooling operation after the initial installation or the defrosting operation has been started. This determination is made based on the on / off state of the compressor 20 and the heater 13 that are grasped by the controller 4, and it can be determined that the cooling operation has started if the heater 13 is off and the compressor 20 is on. When the cooling operation is started, the process proceeds to step ST2, and operation data such as temperature efficiency, fan rotation speed, fan current, and air suction side temperature are measured and calculated. In step ST3, it is determined whether or not learning has been completed. If learning has not been completed, the process proceeds to step ST4, and an average value is obtained based on operation data during normal stable operation in the initial stage of cooling operation in which the evaporator 10 is not frosted. The Mahalanobis distance in the reference state is calculated based on m _i , variance σ _i, and inverse matrix A _ij of the correlation matrix, and the learning value of the calculation result is set as reference data. When learning is completed in step ST4, the determination in step ST3 is followed by a yes loop, that is, a loop after step ST5. In step ST5, the data measured in step ST2 is normalized based on the average value m _i and the variance σ _i . The Mahalanobis distance is calculated based on the data normalized in step ST6 and the inverse matrix A _ij of the correlation matrix used in step ST4. In step ST7, the calculated value of Mahalanobis distance and the learning of the Mahalanobis distance are calculated. The deviation from the value (reference data) is compared with the threshold value stored in the storage means 42. If the Mahalanobis distance deviation is larger than the threshold value, the process proceeds to step ST8 and the defrosting operation is started. Here, the threshold is set to about 4, for example.
In the above example, the Mahalanobis distance is calculated using the inverse matrix of the correlation matrix, but may be calculated using the inverse matrix of the variance-covariance matrix. In this case, since the original data is used instead of the standardized data, the process of step ST5 is not necessary. In step ST4, an inverse matrix of the variance-covariance matrix is used instead of the inverse matrix of the correlation matrix. Details are described in Non-Patent Document 1 above.
In the above example, Mahalanobis distance is used as an example of a method for processing a plurality of parameters, but the present invention is not limited to this. For example, a linear discriminant function may be used. The details are described in Non-Patent Document 1 above.

  As described above, the defrosting operation start time is detected by grasping the frosting state by increasing the Mahalanobis distance using multiple parameters based on the non-frosting state at the start of the cooling operation. In addition, it is possible to determine the defrosting time in consideration of individual differences of the target devices and installation conditions, and it is possible to determine the defrosting time with higher accuracy than in the first embodiment.

  In FIG. 10, every time the cooling operation is started, the evaporator 10 in the initial operation stage is learned as a reference state of the non-frosting state. From this, an average reference state is learned, and thereafter, a method based on this reference state, a method in which a test is performed in advance for each model, and the reference state is stored in the controller 4 may be shipped.

  In the defrosting operation start timing detection method using the Mahalanobis distance described above, four parameters of temperature efficiency, fan speed, fan current, and air suction side temperature are used as composite variables. The present invention is not limited to this, and other parameters that change during frosting such as the refrigeration capacity of the evaporator 10 and the AK value that represents the heat exchange performance of the evaporator 10 may be added or used. For example, it may be a combination of refrigeration capacity, fan speed, air suction side temperature, AK value, fan current, air suction side temperature, etc. These parameters are matched to the detection characteristics of the defrosting operation start timing. All parameters may be used, a combination using a part of them, or other parameters that change when the evaporator 10 is frosted may be further added.

  Hereinafter, the calculation method of the refrigerating capacity and the AK value described above will be described. First, a method for calculating the refrigerating capacity will be described. The refrigerating capacity is the capacity in the evaporator 10, and there are a method of calculating from the air side and a method of calculating from the refrigerant side, but the air side requires an air volume for calculating the refrigerating capacity. Since the change in air volume is large during frost formation and accurate prediction and measurement under low temperature conditions are difficult, the calculation method on the refrigerant side will be described.

The refrigerating capacity Qe [kcal / h] is
Refrigeration capacity Qe = refrigerant flow rate Gr x (evaporator inlet refrigerant enthalpy Hein-evaporator outlet refrigerant enthalpy Heout) (2)
Can be obtained from The refrigerant flow rate Gr [kg / h] is obtained by the following equation according to the characteristics of the compressor 20.
Gr = refrigerant gas density ρ × compressor speed × compressor displacement [m3] × volumetric efficiency ηv
... Formula (3)
Here, x represents multiplication. The refrigerant gas density ρ [kg / m3] can be expressed as a function (approximate expression) of the evaporation temperature Te and the compressor inlet temperature Ts from the physical property value of the refrigerant to be used, and becomes ρ = f (Te, Tsuc). . The compressor rotation speed [1 / h] is expressed as the rotation speed per hour by multiplying the operating frequency [Hz = 1 / sec] (the rotation speed per second) of the compressor 20 by 3600. The compressor displacement volume [m3] is an excluded volume per rotation of the compressor 20. The volumetric efficiency ηv is a coefficient for correcting the flow rate of the compressor 20 and is determined according to the characteristics of the compressor 20 to be used. In addition, the inlet refrigerant enthalpy Hein [kcal / kg] and the outlet refrigerant enthalpy Heout [kcal / kg] are values determined from the refrigerant physical properties, respectively, and are expressed as functions of the refrigerant saturation pressure and temperature using approximate physical property values. Refrigerant enthalpy H = f (saturation pressure P, refrigerant temperature T). Hein can be obtained from the saturation pressure measured by the pre-expansion valve pressure sensor 31 of FIG. 3 and the temperature of the pre-expansion valve temperature sensor 30, and Heout is the compressor suction pressure sensor 34 and the evaporator outlet temperature sensor 32. Can be obtained from

Next, a method for calculating the AK value will be described. The AK value is
AK value [kcal / (h · ° C)] = Refrigeration capacity Qe / (Air suction side temperature Tae−Evaporation temperature Te)
Is calculated from Here, / represents division. The AK value is a value obtained by multiplying the heat transfer rate K and the heat transfer area A in the evaporator 10, and represents the heat transfer characteristics of the evaporator 10.

  As described above, by adding the refrigeration capacity Qe and the AK value to the item of the defrosting operation start timing determination by the composite variable using the Mahalanobis distance, it becomes possible to make a comprehensive determination using a plurality of parameters. The determination accuracy can be further improved.

  It is also possible to determine the defrosting operation start timing using only single parameters such as the refrigerating capacity Qe and the AK value as the determination threshold, and the method is the same as the method based on the temperature efficiency described above.

Embodiment 3 FIG.
Next, a method of determining the frosting state of the evaporator 10 of the cooling device 2 based on the relationship between the outside air temperature humidity and the internal air suction side temperature will be described. In this Embodiment 3, since a frost state changes with the site | parts of the evaporator 10, this is classify | categorized into several types, such as frost type 1, frost type 2, frost type 3 ..., and the said frost type The defrosting start time is changed according to. FIG. 11 is an overall configuration diagram of the cooling system according to the third embodiment of the present invention. In the overall configuration diagram of the cooling system in FIG. 1, an outside temperature sensor 71 and an outside humidity sensor for determining a frosting type are shown. 72 and a door opening / closing detection sensor 73 are added. Here, the door opening / closing detection sensor 73 is not always necessary, and is installed only when it is desired to reliably detect the intrusion state of the outside air load due to the door opening / closing.

  FIG. 12 is a diagram showing the inside / outside temperature / humidity state on the air diagram. The outside temperature / humidity is the outside temperature sensor 71 and the outside humidity sensor 72, and the inside temperature is the air suction side temperature of the cooling device 2. Detected from the sensor 17 or the internal temperature sensor 5, the controller 4 calculates the relationship with the saturation line (line of relative humidity 100%) on the air diagram from these signals. In the air diagram, the horizontal axis is the air dry-bulb temperature and the vertical axis is the absolute humidity. Therefore, when the output from the humidity sensor is relative humidity, it is converted to absolute humidity. This conversion is made possible by storing the relationship between the relative humidity and the absolute humidity with respect to the dry bulb temperature in the storage means 42 as a table, and the calculation means 41 refers to this table. In this configuration, the humidity sensor is not provided in the storage, but the storage is at low temperature and low humidity, and the value is close to zero when the continuous operation is performed. Calculates the relationship with the saturation line assuming that the inside humidity is zero. It is also possible to increase the detection accuracy by adding a humidity sensor to the inside of the cabinet, or to adjust the assumed value of the absolute humidity inside the cabinet to a value other than zero in accordance with the actual machine operating state.

  Next, a method for calculating the relationship with the saturation line (line with a relative humidity of 100%) on the air diagram will be described. The relationship between the dry bulb temperature (horizontal axis) and the absolute humidity (vertical axis) of the saturation line on the air diagram is stored in the storage means 42 of the controller 4 as a data table. This data table is composed of values of dry bulb temperature and absolute humidity on the saturation line. For example, in the target cooler 2 and the dry bulb temperature range of the outside air (eg, −50 ° C. to 50 ° C.), for example, dry bulb temperature 1 The value of saturation absolute humidity is stored for each degree in degrees Celsius. The step size of the dry bulb temperature can be adjusted according to the capacity of the storage means 42, and the interval between the step sizes can be estimated by linear interpolation.

  The inside / outside temperature / humidity position on the air diagram can be found from the sensor information as described above. Here, the slope α of the straight line connecting the inside / outside temperature / humidity position on the air diagram is obtained from α = (absolute outside humidity−internal humidity) / (outside dry bulb temperature−inside dry bulb temperature). It is done. Therefore, the absolute humidity X with respect to an arbitrary dry bulb temperature Tx on the straight line connecting the inside and outside temperature / humidity points on the air diagram is X = inside absolute humidity + (Tx−inside dry bulb temperature) × α. Is calculated by the calculation means 41. Here, / represents division, and x represents multiplication.

  The magnitude of the absolute humidity X on the straight line connecting the outside temperature / humidity point and the inside temperature / humidity point described above, and the absolute humidity (vertical axis) on the air diagram saturation line stored as a table in the storage means 42. , For example, in increments of 1 ° C. (dry bulb temperature: range between the inside bulb temperature and the outside bulb temperature), the straight line connecting the inside and outside temperature / humidity points is saturated by the comparison means 43. Whether it passes above the line (passes oversaturated region) or not can be determined. As a result of comparison, a case where a straight line connecting the inside and outside temperature / humidity points passes through the supersaturated region above the saturation line is regarded as one frosting type (hereinafter referred to as frosting type 1) and does not pass through the supersaturated region. The determination unit 44 classifies the case as another frost type (hereinafter referred to as frost type 2).

  In addition, even when the frosting type 1 and the frosting type 2 are classified as described above, the frost melts when the value of the air suction side temperature sensor 17 may be 0 ° C. or more. This case is further classified by the judging means 44 as another frost type (hereinafter referred to as frost type 3). Regarding the determination of whether the frosting type 3 or any other frosting type 1 or frosting type 2, the air suction side temperature sensor 17 is 0 ° C. or more during one cycle of frosting operation. The determination can be made by assuming that the predetermined time ratio is equal to or greater than A% (for example, 10%).

Next, the characteristics of the frosting molds 1 to 3 will be described.
In the case of the inside / outside air condition of the frosting type 1, when the door 6 of the freezer warehouse 1 is opened / closed, the high temperature / high humidity air outside the storage and the low temperature / low humidity air inside the storage are in direct contact with each other. The mixed air becomes supersaturated and becomes “snow-filled air” in which moisture in the air becomes snowy. This snow-filled air is sucked into the cooling device 2 along the flow of airflow in the freezer warehouse 1, and snow adheres to the inlet side of the evaporator 10. The evaporator 10 is generally composed of a heat transfer pipe and a large number of plate-like fins, and since the pitch of the fins is as fine as about several millimeters, when the snow adheres to the fins, the gap between the fins becomes clogged, the air volume decreases, It adversely affects cooling performance such as deterioration of heat transfer characteristics. Moreover, the snow adhering to the evaporator 10 has a lower density than the frost generated in the evaporator 10 due to the condensation and freezing of water in the air, and is easily clogged even if a small amount adheres. Cooling performance will deteriorate over time. For this reason, since the frost formation type | mold 1 causes the air inlet side clogging of the evaporator 10 in a short time, it is necessary to advance the defrosting operation start time earlier than a timer setting cycle (assuming the frost formation type 2), such as normal 6 hours. There is.

  Whether the door has been opened or closed is determined by monitoring the temperature of the air suction side temperature sensor 17 or the internal temperature sensor 5 with the controller 4, and these temperatures rise above the internal temperature set value. It is possible to determine that the door has been opened / closed when the temperature rises to a set threshold value or higher, for example, 10 ° C. or higher. In particular, it is possible to accurately detect the opening and closing of the door by placing the internal temperature sensor 5 near the door. Further, by detecting the door opening / closing by the door opening / closing detection sensor 73, the door opening / closing can be reliably detected.

  Next, features of the frosting mold 2 will be described. In the case of the inside / outside air condition of the frosting type 2, even if the door is opened and closed and the high temperature / high humidity air outside the storage is in direct contact with the low temperature / low humidity air inside the storage, In addition, the moisture in the air does not become snowy. For this reason, the evaporator 10 is in a normal frosting state in which moisture in the air is condensed and frozen to be generated in the evaporator 10. Therefore, in the frosting mold 2, the defrosting operation start timing may be equivalent to the normal cycle.

  The criteria for separating frosting molds 1 and 2 depend on whether or not the door has been opened and closed, and whether or not the inside / outside temperature / humidity passes through the supersaturated region on the air diagram when the door is opened / closed. For this reason, during the frost operation, the door is opened and closed, and the time when the inside / outside temperature / humidity passes through the supersaturated region on the air diagram is counted as a timer, and the counted time is one cycle in the frost operation. Separation determination can be performed by determining the frosting type 1 when the ratio is equal to or greater than a predetermined ratio B% (for example, 10%) set in advance.

  In the frosting type 3, since the value of the air suction side temperature sensor 17 may be 0 ° C. or more, the frost adhering to the evaporator 10 repeats melting and refreezing, and the frost has a high density close to ice. Further, the evaporator 10 having several rows of paths with respect to the air flow generally has the air flow and the flow direction of the heat medium flowing through the evaporator 10 facing each other in order to improve heat exchange performance. There are many. The heat medium flowing in the evaporator 10 has a low temperature on the outlet side (downstream side) of the air flow, and gradually exchanges heat, and the temperature tends to rise on the inlet side (upstream side) of the air flow. For this reason, frost is easily melted on the air flow inlet side of the heat exchange air, and is difficult to refreeze, and much frost adheres to the air flow outlet side of the low temperature heat exchange air. In the frosting type 3, since the frost density is high and it is difficult to block the air passage even if frosting occurs, the cooling efficiency is gradually lowered, and the frosting cycle can be made longer than usual.

FIG. 13 is a flowchart showing the frosting type determination process according to the third embodiment of the present invention, which is processed by the defrosting time determination means 50 of the controller 4.
The flow of the above frost formation type determination is shown in the flowchart of FIG.
In step ST1, the defrosting time determination means 50 completes the first cooling by completing the previous defrosting operation and lowering the evaporation temperature from the high chamber temperature after the defrosting to the target temperature. Determine whether or not. If the determination result in step ST1 is No, the process proceeds to step ST2, and the defrosting time determination means 50 resets each timer (described later). If the determination result in step ST1 is Yes, the process proceeds to step ST3, and the defrosting time determination means 50 starts counting Timer_ALL, which is a timer for one cycle frosting operation total time. Next, in step ST4, the defrosting time determination means 50 determines whether or not the air suction side temperature of the evaporator 10 is 0 ° C. or higher, and counts the timer 1 (Timer_1) if it is 0 ° C. or higher. (Step ST5). In step ST6, the defrosting time determination means 50 obtains the ratio of the accumulated time of the timer 1 (Timer_1) to the total cycle frosting operation time (Timer_ALL), and when it is A% or more (for example, 10%) It determines with the type | mold 3 (step ST13). In step ST7, the defrosting time determination means 50 determines whether the door is open / closed based on the temperature transition of the air suction side temperature sensor 17 or the internal temperature sensor 5, or the output of the door open / close detection sensor 73, and the door is open / closed (Yes). In step ST8, it is determined whether or not the line connecting the inside / outside temperature / humidity on the air diagram passes through the supersaturated region. If it is determined in step ST8 that the supersaturated region is passed (Yes), the timer 2 (Timer_2) is counted. When the determination result of step ST10 is the ratio of the accumulated time of the timer 2 (Timer_2) to the total cycle frosting operation total time (Timer_ALL) and is B% or more (for example, 10%) (Yes), The defrosting time determining means 50 determines the frosting type 1 (step ST11). Moreover, when the determination result of step ST10 is No, the defrosting time determination means 50 determines with the frost type 2 (step ST12).

Next, the detection method of frost formation type | mold 1-3 and the defrost method suitable for each are demonstrated.
FIG. 14 shows an example of monitoring the transient change state of the frosting type 1, FIG. 15 is the frosting type 3, and FIG. 5 is the temperature efficiency described above, and the horizontal axis is the amount of frosting. Represents.

  In the frosting type 1, clogging occurs rapidly because snow with a low density adheres to the air suction side of the evaporator 10. For this reason, temperature efficiency falls rapidly compared with another frost type. When the evaporator 10 is clogged, the cooling efficiency is lowered and the efficiency of the cooling device 2 is lowered. Therefore, it is necessary to start the defrosting operation before the clogging occurs. Therefore, the defrosting operation is performed in a cycle shorter than the normal defrosting cycle. As shown in FIG. 14, if the temperature efficiency is monitored and an appropriate threshold value (0.4 in the example in the figure) is set, the defrosting operation can be performed at the optimum defrosting start timing.

  Although the frosting mold 2 has been described with reference to FIG. 5 described above, the frosting mold 2 is a standard frosting state in which moisture in the air is uniformly frosted on the evaporator 10 when there is no outside air load intrusion by opening and closing the door. An efficient cooling operation can be performed by performing the defrosting operation at the normal defrosting timing.

  The frosting type 3 has a high frost density adhering to the evaporator 10 and is less likely to block the air passage. Therefore, the cooling performance is gradually lowered, and the defrosting start timing is delayed as compared with other frosting types. Is possible. Further, as shown in FIG. 15, the temperature efficiency declines gradually, so there is a possibility of a detection delay, and the threshold of the temperature efficiency at the start of defrosting is set slightly higher than other frosting types to make it earlier. It is good also as control which starts a defrost driving | operation.

As described above, the temperature efficiency shown in the first embodiment has been described as the parameter for detecting the defrosting start time corresponding to the frosting type, but the AK value is applied instead of the temperature efficiency in the first embodiment. Or what applied refrigeration capacity may be used in this Embodiment 3. In this case, the same effect as described above can be obtained.
Further, even when the timer defrost control is performed without using such a parameter for detecting the defrost start time, the frost type determination is performed, and the timer defrost interval is shortened in the frost type 1 according to the frost type. The frosting mold 3 may be configured to increase the timer defrosting interval. In this case, the same effect as described above can be obtained.
Furthermore, a composite function may be generated by adding the temperature efficiency shown in the first embodiment as a parameter in the second embodiment, and this composite function may be used in the third embodiment. This makes it possible to determine the defrosting start time with higher accuracy.
In the second embodiment, a composite function may be generated by adding the AK value or the refrigerating capacity as a parameter instead of the temperature efficiency, and this composite function may be used in the third embodiment. Accordingly, it is possible to determine the defrosting start time with higher accuracy in the same manner.

Embodiment 4 FIG.
Next, a description will be given of a method for suppressing the temperature fluctuation in the refrigerator using frosting type detection.
FIG. 16 is a cross-sectional view of the cooling device according to the fourth embodiment of the present invention, in which the evaporator 10 of the cooling device 2 is divided into two in the front-rear direction with respect to the air flow direction. Here, the evaporator 10a and the heater 13a are installed on the upstream side of the air flow, the evaporator 10b and the heater 13b are installed on the downstream side, and the heater 13 can be heated separately in the front and rear. In the case of the frosting type 1, the air suction side of the evaporator 10 is clogged early, and the defrosting operation is performed in a short time. When the frosting type 1 is determined, only the suction-side evaporator 10 is heated for a predetermined time (about 2 to 3 minutes), and the suction part of the evaporator 10 is brought into the plus temperature range, thereby adhering to the evaporator 10. The melted snow can be melted and the cooling performance can be suppressed. Thereby, also in the frosting type | mold 1, it becomes possible to extend a defrost operation space | interval, and it can transfer the defrost operation to night with little load fluctuation, for example, and can prevent degradation by the temperature rise of a frozen object.
In the above example, the fourth embodiment is applied to the third embodiment, but the present invention is not limited to this. That is, the fourth embodiment can be applied to a combination of one or more of the first to third embodiments. In this case, the same effect as described above can be obtained.
In addition to the heating by the heater 13, heating by hot gas may be performed.
Moreover, although said example demonstrated the frozen warehouse, it is not restricted to this. For example, a refrigerated warehouse or a constant temperature room may be used.

It is a whole block diagram of the cooling system in Embodiment 1 of this invention. It is sectional drawing of the cooling device of Embodiment 1 of this invention. It is a figure showing the refrigerating cycle of the freezing apparatus in Embodiment 1 of this invention. It is a block diagram of the controller in Embodiment 1 of this invention. It is a figure which shows the relationship between the amount of frost formation in Embodiment 1 and 3 of this invention, temperature efficiency, and a refrigerator average input increase rate. It is the figure which represented the temperature efficiency of Embodiment 1 of this invention on the air diagram. It is a flowchart which shows the defrosting time determination process at the time of using the temperature efficiency of Embodiment 1 of this invention. It is a flowchart which shows the defrosting time determination process at the time of using the temperature efficiency of Embodiment 1 of this invention, and performing initial learning. It is sectional drawing of the cooling device of Embodiment 2 of this invention. It is a flowchart which shows the defrosting time determination method at the time of using the composite variable of Embodiment 2 of this invention. It is a whole block diagram of the cooling system of Embodiment 3 of this invention. It is the figure which represented the internal / external temperature / humidity state of Embodiment 3 of this invention on the air diagram. It is a flowchart which shows the frost formation type | mold determination process of Embodiment 3 of this invention. It is a figure which shows the relationship between the amount of frost formation in the frost formation type | mold 1 of Embodiment 3 of this invention, temperature efficiency, and a refrigerator average input increase rate. It is a figure which shows the relationship between the amount of frost formation in the frost formation type | mold 3 of Embodiment 3 of this invention, temperature efficiency, and a refrigerator average input increase rate. It is sectional drawing of the cooling device of Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerated warehouse, 2 Cooling device, 3 Outdoor unit, 4 Controller, 5 Internal temperature sensor, 6 door, 7 Refrigerant piping, 10 Evaporator, 11 Blower fan, 12 Motor, 13 Heater, 14 Drain pipe, 15 Drain pan, 16 Evaporation temperature sensor, 17 Air suction side temperature sensor, 18 Air outlet side temperature sensor, 20 Compressor, 21 Condenser, 22 Expansion valve, 30 Expansion valve pre-temperature sensor, 31 Expansion valve pre-pressure sensor, 32 Evaporator outlet temperature sensor , 33 Compressor suction temperature sensor, 34 Compressor suction pressure sensor, 41 Calculation means, 42 Storage means, 43 Comparison means, 44 Judgment means, 45 Input / output means, 46 Control means, 50 Defrost timing judgment means, 61 Fan rotation Sensor, 62 Fan current sensor, 71 Outside temperature sensor, 72 Outside humidity sensor, 73 Door open / closed detection sensor.

Claims (21)

The air intake side temperature of the heat exchanger used on the cooling side of the refrigerator or air conditioner, and
Measuring means for measuring the temperature and humidity outside the room to be cooled;
A determination unit that identifies a frost formation part of the heat exchanger based on a result measured by the measurement unit and determines a defrosting start time ;
With
In the air diagram, the determination means determines that the straight line connecting the outside air temperature humidity and the air suction side temperature humidity of the heat exchanger or the temperature humidity in the cooling target room enters a region exceeding a saturation line. exchanger first first defrosting operation controller you characterized in that classified as frost type corresponding to the frost to the site of. The air intake side temperature of the heat exchanger used on the cooling side of the refrigerator or air conditioner, and
Measuring means for measuring the temperature and humidity outside the room to be cooled;
A determination unit that identifies a frost formation part of the heat exchanger based on a result measured by the measurement unit and determines a defrosting start time ;
With
The measuring means further detects opening and closing of the door of the cooling target chamber,
The determination means detects the opening and closing of the door by the measuring means, and in the air diagram, the outside air temperature humidity outside the cooling target room and the air suction side temperature humidity of the heat exchanger or the cooling target room dividing a straight line connecting the temperature and humidity, the you characterized be classified as a first frost type corresponding to frosted cases entering the area beyond the saturation line, the first portion of the heat exchanger Frost operation control device. The defrosting operation control device according to claim 1 or 2 , wherein the first part is an air suction side. When the air suction temperature of the heat exchanger is in a plus region exceeding 0 ° C. for a certain time or more, the determination means is a second frosting type corresponding to frosting on the second part of the heat exchanger. It is classified as defrosting operation control device according to any one of claims 1 to 3, characterized in. The defrosting operation control device according to claim 4 , wherein the second part is an air blowing side. The measuring means further measures the temperature of the refrigerant flowing in the heat exchanger, the air suction side temperature and the blowout side temperature of the heat exchanger,
Means for calculating temperature efficiency representing the efficiency of heat exchange between refrigerant and air based on the result of measurement by the measuring means (hereinafter referred to as computing means);
The determination means predicts a frost formation amount to the heat exchanger based on a change tendency from the start of a frost operation of the temperature efficiency calculated by the calculation means, and an optimum defrosting is based on the frost formation amount. The defrosting operation control device according to any one of claims 1 to 5, wherein a start time is determined. The measuring means further measures the current or rotation speed of a fan motor for an air heat exchanger of the refrigerator or air conditioner,
The calculation means is not attached based on at least one of the current and rotation speed of the fan motor and the air suction side temperature of the heat exchanger measured by the measurement means in the non-frosting state and the calculated value of the temperature efficiency. Calculate the frost condition compound variable,
Means for storing the composite variable of the non-frosting state (hereinafter referred to as storage means);
The composite variable of the non-frosting state stored in the storage means, the current measurement value and rotation speed of the fan motor newly measured by the measurement means, and at least one of the air suction side temperature of the heat exchanger, and the Means for comparing the current composite variable calculated by the calculation means based on temperature efficiency (hereinafter referred to as comparison means),
Whether the heat exchanger is frosted based on information on whether the comparison result by the comparison means exceeds a threshold value stored in advance in the storage means instead of the change tendency of the temperature efficiency. The defrosting operation control device according to claim 6 , wherein the determination and the prediction of the amount of frost formation are performed. A defrosting operation control device used in a refrigerator or an air conditioner composed of a compressor, a condenser, an expansion valve, and an air-cooled evaporator,
The measurement means further includes refrigerant suction gas pressure and temperature to the compressor, discharge refrigerant pressure of the compressor or refrigerant pressure before the expansion valve, refrigerant temperature before the expansion valve, and outlet refrigerant temperature of the air-cooled evaporator. And measure
Means for calculating the refrigeration capacity of the air-cooled evaporator based on the result measured by the measuring means (hereinafter referred to as computing means);
The determination means predicts a frost formation amount to the heat exchanger based on a tendency of change of the refrigeration capacity calculated from the calculation means from the start of the frost formation operation, and based on the frost formation amount, an optimum defrosting is predicted. The defrosting operation control device according to any one of claims 1 to 5, wherein a start time is determined. The measuring means further measures the current or rotation speed of a fan motor for an air heat exchanger of the refrigerator or air conditioner,
The calculation means is non-attached based on at least one of the current and rotation speed of the fan motor and the air suction side temperature of the heat exchanger measured by the measurement means in the non-frosting state and the calculated value of the refrigeration capacity. Calculate the frost condition compound variable,
Means for storing the composite variable of the non-frosting state (hereinafter referred to as storage means);
The composite variable of the non-frosting state stored in the storage means, the current measurement value and rotation speed of the fan motor newly measured by the measurement means, and at least one of the air suction side temperature of the heat exchanger, and the Means for comparing the current composite variable calculated by the calculation means based on the refrigerating capacity (hereinafter referred to as comparison means),
Whether the heat exchanger is frosted based on information on whether the comparison result by the comparison means exceeds a threshold value stored in advance in the storage means instead of the change tendency of the refrigeration capacity. The defrosting operation control device according to claim 8 , wherein determination of whether or not and prediction of the amount of frost formation are performed. A defrosting operation control device used in a refrigerator or an air conditioner composed of a compressor, a condenser, an expansion valve, and an air-cooled evaporator,
The measuring means further includes an air temperature for heat exchange with the air-cooled evaporator, an evaporation temperature of the air-cooled evaporator, a pressure and temperature of refrigerant suction gas to the compressor, and a pressure of refrigerant discharged from the compressor or Measure the refrigerant pressure before the expansion valve, the refrigerant temperature before the expansion valve, and the evaporator outlet refrigerant temperature,
A means for calculating the refrigeration capacity of the air-cooled evaporator based on the result of measurement by the measuring means, and a means for calculating an AK value based on the refrigeration capacity, the heat transfer area of the air-cooled evaporator, and the heat passage rate (hereinafter, calculating means) And)
The determination means predicts a frost formation amount to the heat exchanger based on a change tendency of the AK value calculated by the calculation means from the start of the frost formation operation, and based on the frost formation amount, an optimum defrosting is predicted. The defrosting operation control device according to any one of claims 1 to 5, wherein a start time is determined. The measuring means further measures the current or rotation speed of a fan motor for an air heat exchanger of the refrigerator or air conditioner,
The calculation means is non-attached on the basis of at least one of the current and rotation speed of the fan motor measured by the measurement means in the non-frosting state, the air suction side temperature of the heat exchanger, and the calculated value of the AK value. Calculate the frost condition compound variable,
Means for storing the composite variable of the non-frosting state (hereinafter referred to as storage means);
The composite variable of the non-frosting state stored in the storage means, the current measurement value of the fan motor newly measured by the measurement means, the rotational speed, and the air suction side temperature of the heat exchanger, and the Means for comparing the current composite variable calculated by the calculation means based on an AK value (hereinafter referred to as comparison means);
Whether the heat exchanger is frosted based on the information whether the comparison result by the comparison means exceeds a threshold value stored in advance in the storage means instead of the change tendency of the AK value. The defrosting operation control device according to claim 10 , wherein the determination of frost and the amount of frost formation are performed. The determination means measures the time from the start of the cooling run, to any one of claims 1 to 5, characterized in that to determine the defrosting start timing on the basis of the frost type after a certain time set Defrosting operation control apparatus of description. The defrosting operation control device according to any one of claims 7 to 12 , wherein the current composite variable or the composite variable of the non-frosting state is a Mahalanobis distance. The defrosting operation control device according to any one of claims 7 to 12 , wherein the current composite variable or the composite variable of the non-frosting state is a linear discriminant function. It said heat exchanger is divided into a plurality air flow direction, further comprising a defrosting means capable individual defrosting control by a heater or hot gas for each divided heat exchanger claim 1, wherein the 14 The defrosting operation control device according to any one of the above. The defrosting operation control device according to any one of claims 1 to 15 , further comprising means for controlling the defrosting operation based on the defrosting start time calculated by the defrosting start time determining means. Measuring the air suction side temperature of the heat exchanger used on the cooling side of the refrigerator or air conditioner and the temperature and humidity outside the cooling target chamber (hereinafter referred to as measurement step);
Identifying a frost formation part of the heat exchanger based on the result measured in the measurement step, and determining a defrosting start time (hereinafter referred to as a determination step);
With
In the determination step, in the air diagram, when the straight line connecting the outside air temperature humidity and the air suction temperature / humidity of the heat exchanger or the temperature / humidity in the cooling target room enters the region exceeding the saturation line, the heat exchanger first defrosting operation control how to said be classified as frost type corresponding to the frost to the first site of. The determination step includes a step of detecting opening and closing of the door of the cooling target chamber, and further, in the air diagram, the outside air temperature humidity outside the cooling target chamber and the air suction side temperature humidity of the heat exchanger or the cooling The case where the straight line connecting the temperature and humidity in the target room enters the region exceeding the saturation line is classified as a first frosting type corresponding to frosting on the first part of the heat exchanger. The defrosting operation control method according to claim 17 . In the determination step, a case where the air suction temperature of the heat exchanger is in a plus region exceeding 0 ° C. for a certain time or more is defined as a second frost type corresponding to frost formation on the second part of the heat exchanger. The defrosting operation control method according to claim 17 or 18 , wherein classification is performed. In the determination step, by measuring the time from the start of the cooling run, in any of 19 claims 17, characterized in that to determine the defrosting start timing on the basis of the frost type after a certain time set The defrosting operation control method described. The defrosting operation control method according to any one of claims 17 to 20 , further comprising a step of controlling the defrosting operation based on the defrosting start time determined in the determination step.

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