JP6636155B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigerating apparatus, and more particularly to a method for determining whether a condenser is clogged.

  2. Description of the Related Art Conventionally, in an air-cooled fin tube type condenser provided in a refrigerating apparatus, dust and dirt tend to adhere to gaps between fins, and clogging may occur with long-term use. This clogging reduces the heat radiation performance of the condenser, and the heat radiation performance of the condenser lowers the performance of the refrigeration system. In some cases, there is a problem that the high pressure cut causes an abnormal stop.

  2. Description of the Related Art Conventionally, manuals and the like often prompt visual confirmation of dirt on a condenser and periodic cleaning of fins, and it is left to a user to determine whether the condenser is clogged. For example, even if clogging has occurred, if the end user does not recognize dirt on the fins, clogging may be found in summer due to an abnormal stop due to an increase in pressure. However, when the outside air temperature in winter is low, even if clogging occurs, the pressure does not increase enough to cause an abnormal stop, and the operation may continue while consuming more power than necessary.

  Therefore, when clogging occurs in the condenser, a refrigerating apparatus that determines clogging of the condenser by utilizing the fact that the condensing temperature rises compared to the outside air temperature due to insufficient cooling of the condenser has been proposed. (For example, see Patent Document 1).

  The refrigeration apparatus described in Patent Literature 1 includes a temperature sensor that detects a condensing temperature and a temperature sensor that detects an outside air temperature, and when a difference between the condensing temperature and the outside air temperature becomes equal to or more than a threshold for clogging determination. It is determined that the condenser is clogged. When it is determined that the condenser is clogged, the power supply of the refrigerant circuit is cut off or an alarm is activated. This makes it possible to determine whether the condenser is clogged irrespective of summer or winter.

Japanese Utility Model Application Laid-Open No. 4-20972

  In the conventional refrigeration apparatus described in Patent Literature 1, the condensation temperature rises in proportion to the outside air temperature, and a threshold for determining clogging is uniquely determined. However, in the case of a refrigeration apparatus provided with an inverter, the operating frequency and the fan output greatly vary depending on the environment and conditions, and the condensing temperature also varies greatly. Therefore, the difference between the condensing temperature and the outside air temperature is not stable, and it is determined that clogging has occurred despite the fact that the condenser is hardly clogged. Nevertheless, there has been a problem that it is determined that clogging has not occurred.

  In addition, a temperature detector such as a thermistor or a temperature sensor is used to detect the condensation temperature and the outside air temperature. However, since these temperature detectors have a detection error, the rate at which clogging can be detected due to this error is large. Change.

FIG. 7 is a diagram illustrating an example of an influence of a detection error of the temperature detection unit on a ratio of detectable clogging.
For example, if the variation of the condensation temperature data by the temperature detection unit is 1.50K at the maximum and the variation of the outside temperature data is 1.20K at the maximum, the maximum variation at 3σ when the difference between the condensation temperature and the outside temperature is taken is ± 1. .90K. As shown in FIG. 7, when the clogging of the condenser is 0%, the difference between the condensation temperature and the outside air temperature is +2.40 K, and the clogging ratio is 48%. Then, in consideration of the variation of the temperature detection unit, the value that may be detected is + 0.50K to + 4.30K, and the clogging ratio is 13% to 71%.

  In other words, depending on the detection error of the temperature detector, it is determined that clogging has occurred because the difference between the condensing temperature and the outside air temperature is greater than the threshold for clogging determination even though clogging has not occurred. Or conversely, even though clogging has occurred, it is determined that clogging has not occurred without the difference between the condensation temperature and the outside air temperature being larger than the threshold for clogging determination. There was a problem of getting it.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a refrigeration apparatus that can appropriately determine clogging of a condenser.

The refrigeration apparatus according to the present invention includes a compressor, a condenser having a fan, and a heat source side unit having a liquid receiver, a load side unit having an expansion valve and an evaporator, the heat source side unit, and A load side unit is connected by piping, the compressor, the condenser, the expansion valve, and a refrigerant circuit that sequentially circulates refrigerant through the evaporator, and a control device that determines whether the condenser is clogged, The control device includes a first temperature detecting unit that detects a condensing temperature and a second temperature detecting unit that detects an outside air temperature, wherein the control device detects the condensing temperature detected by the first temperature detecting unit and the second temperature detecting unit. And a determination unit that determines whether or not the condenser is clogged using the temperature difference based on the outside air temperature and a threshold value A, wherein the determination unit determines whether the output of the fan is If the maximum is the clogging It is intended to perform a constant, the threshold value A, the first temperature detection unit and the maximum value is greater than value of the detection error of the second temperature detector, and, with the condensation temperature in clogging rates that do not abnormal operation The larger of the differences from the outside air temperature is set .

  According to the refrigeration apparatus of the present invention, the temperature difference between the first temperature detection unit and the second temperature detection unit is calculated based on the condensing temperature and the outside air temperature detected, and the temperature difference is corrected. Using the temperature difference and the threshold value A, it is determined that the condenser is clogged. Therefore, regardless of the detection error of the first temperature detection unit and the second temperature detection unit, it is possible to appropriately determine whether the condenser is clogged without being undetectable or causing erroneous detection.

FIG. 2 is a refrigerant circuit diagram illustrating a refrigeration apparatus according to Embodiment 1 of the present invention. FIG. 3 is a functional block diagram of a control device of the refrigeration apparatus according to Embodiment 1 of the present invention. It is a figure which shows the change of the threshold value which determines the clogging of the condenser accompanying the change of evaporation temperature. 5 is a control flow for judging and reporting clogging of the condenser by the refrigeration apparatus according to Embodiment 1 of the present invention. It is a functional block diagram of a control device of a refrigeration apparatus according to Embodiment 2 of the present invention. 9 is a control flow for determining and notifying clogging of a condenser by a refrigeration apparatus according to Embodiment 2 of the present invention. It is a figure showing an example of an influence which a detection error of a temperature detection part has on a rate of clogging which can be detected.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited by the embodiments described below. Further, in the following drawings, the size relationship of each component may be different from the actual one.

Embodiment 1 FIG.
FIG. 1 is a refrigerant circuit diagram illustrating a refrigeration apparatus according to Embodiment 1 of the present invention.
As shown in FIG. 1, the refrigeration apparatus according to Embodiment 1 includes a heat source side unit 100 and a load side unit 200.
The heat source side unit 100 includes a compressor 1, a condenser 2, and a liquid receiver 3, and corresponds to, for example, a condensing unit. The compressor 1 is designed to be driven by an inverter. The condenser 2 has a fan 6 in the vicinity thereof for promoting heat exchange between the refrigerant in the condenser 2 and the outside air. The liquid receiver 3 is provided on the outlet side of the condenser 2 and stores excess refrigerant.
The load-side unit 200 includes the expansion valve 4 and the evaporator 5, and corresponds to, for example, a showcase or a unit cooler.

  The heat source side unit 100 and the load side unit 200 are connected by a local liquid extension pipe 20 and a local gas extension pipe 21. A refrigerant circuit for sequentially circulating the refrigerant to the compressor 1, the condenser 2, the liquid receiver 3, the expansion valve 4, and the evaporator 5 is configured.

  The heat source side unit 100 includes a pressure detector 7 for detecting the pressure on the suction side of the compressor 1, a first temperature detector 8 for detecting the temperature of the refrigerant on the outlet side of the condenser 2, and a fan And a second temperature detecting unit 9 for detecting the temperature of the air before being sent to the air. The first temperature detector 8 and the second temperature detector 9 are, for example, thermistors or temperature sensors. The pressure detection unit 7 is, for example, a pressure sensor. Hereinafter, the first temperature detector 8 and the second temperature detector 9 are collectively referred to as a temperature detector.

  The pressure detected by the pressure detection unit 7 is converted and used as the evaporation temperature of the evaporator 5 mounted on the load-side unit 200 for clogging determination described later. The temperature detected by the first temperature detection unit 8 is used as a condensation temperature in the later-described clogging determination, and the temperature detected by the second temperature detection unit 9 is used as an outside air temperature in a later-described clogging determination. Is done.

  In the first embodiment, it has been described that the condensing temperature is detected by the first temperature detecting unit 8 provided at the outlet of the condenser 2, but instead of the first temperature detecting unit 8, the discharge of the compressor 1 is performed. A pressure detecting unit (not shown) for detecting the pressure on the compressor side may be provided, and the pressure on the discharge side of the compressor 1 detected by the pressure detecting unit may be converted into the condensation temperature. Even when the pressure on the discharge side of the compressor 1 is used, the value converted from the pressure to the condensing temperature and the value detected by the second temperature detection unit 9 at the time of energization before the start of operation and the like are compared, and the difference between the values is determined. The error may be corrected so as to eliminate the error. In addition, a temperature detection unit and a pressure detection unit may be appropriately provided according to the specification of the heat source side unit 100 of the refrigeration apparatus, and the condensation temperature may be obtained according to the provided temperature detection unit and pressure detection unit.

  The refrigerating apparatus includes an inverter board 10 for changing the operating frequency of the compressor 1, a display unit 11 for performing clogging notification and the like, control of the operating frequency of the compressor 1, control of the output of the fan 6, and pressure detecting unit. 7, processing of the values detected by the first temperature detecting unit 8 and the second temperature detecting unit 9, correction of a detection error of the temperature detecting unit described later, clogging determination, and indication of clogging notification to the display unit 11, etc. And a control device 30 for performing the control.

  The control device 30 includes, for example, a microcomputer, and the display unit 11 includes, for example, a 7-segment LED. The inverter board 10, the control device 30, and the display unit 11 may be integrally formed with the heat source side unit 100 or may be provided separately, so that they can communicate with the heat source side unit 100. It just needs to be.

FIG. 2 is a functional block diagram of control device 30 of the refrigeration apparatus according to Embodiment 1 of the present invention.
As illustrated in FIG. 2, the control device 30 includes a determination unit 31 that performs various determinations, a time measurement unit 32 that measures time, a compressor control unit 33 that controls the compressor 1, and a fan that controls the fan 6 A control unit 34, a pressure data acquisition unit 35 that acquires data relating to the pressure detected by the pressure detection unit 7 (hereinafter, referred to as pressure data), and an evaporation temperature in the evaporator 5 based on the pressure data acquired by the pressure data acquisition unit 35. And a calculation unit 36 for obtaining a threshold value A for clogging determination determined according to the evaporation temperature, and data relating to the temperatures detected by the first temperature detection unit 8 and the second temperature detection unit 9 (hereinafter referred to as temperature data). ), A correction unit 38 that corrects the temperature data obtained by the temperature data obtaining unit 37 using correction data obtained in advance, and a display unit 11. A display section control section 39, and a. In the first embodiment, the correction data is stored in the correction unit 38, but is not limited thereto, and may be stored in, for example, a storage unit (not shown).

Next, the operation of the refrigeration apparatus according to Embodiment 1 will be described.
As shown in FIG. 1, the refrigerant in the refrigerant circuit is compressed into a high-temperature and high-pressure superheated gas by a compressor 1 mounted on the heat source side unit 100, and then is cooled by a condenser 2 from a refrigerant superheated gas such as air. It exchanges heat with a medium having a low temperature and is condensed into a medium-temperature and high-pressure liquid refrigerant. The liquid refrigerant is stored in the liquid receiver 3. The liquid refrigerant that has exited the liquid receiver 3 passes through the local liquid extension pipe 20 and is converted into a low-temperature, low-pressure gas-liquid two-phase refrigerant by the expansion valve 4 mounted on the load-side unit 200. Then, the heat is exchanged with the surrounding air and water in the evaporator 5, turned into a low-pressure superheated gas, and then passed through the local gas extension pipe 21 and sucked into the compressor 1 again. This series of operations constitutes a refrigeration cycle of the refrigerant circuit.

Next, a correction for a detection error of the first temperature detection unit 8 and the second temperature detection unit 9 that is performed in advance when performing clogging determination of the condenser 2 described below will be described.
The correction for the detection error of the first temperature detecting unit 8 and the second temperature detecting unit 9 does not need to be performed so that each of the temperature detecting units matches the true value, and the first temperature detecting unit 8 and the second temperature detecting unit 9 are not required. It suffices that the value of the error with respect to the true value is the same in each of 9.

  Therefore, the timing for calculating the correction data used when correcting the temperature data detected by the first temperature detection unit 8 and the second temperature detection unit 9 is determined by the first temperature detection unit 8 and the second temperature detection unit. Conditions under which the values detected in 9 are the same, for example, during energization before the start of operation, may be good. At the time of energization before the start of operation, the first temperature detection unit and the second temperature detection unit detect the temperature. Then, the correcting unit 38 automatically corrects one of the temperature data so that the difference becomes zero if there is a difference between the values detected by the first temperature detecting unit 8 and the second temperature detecting unit 9. Is calculated, and the correction data is stored in itself. It should be noted that once this correction data is calculated, it is not necessary to calculate thereafter.

Next, a control in which the refrigeration apparatus according to the first embodiment determines whether or not clogging of the condenser 2 has occurred and notifies the occurrence of clogging will be described.
Specifically, the temperature data acquisition unit 37 of the heat source side unit 100 acquires the condensation temperature data and the outside air temperature data detected by the first temperature detection unit 8 and the second temperature detection unit 9, and the correction unit 38 The temperature data and the outside air temperature data are corrected by correction data calculated in advance, and the determination unit 31 determines that the temperature difference ΔT (= condensation temperature−outside air temperature) is larger than a threshold value A set to a predetermined value. If it is, it is determined that the condenser 2 is clogged. When it is determined that the condenser 2 is clogged, the display control unit 39 instructs the display unit 11 to notify that the condenser 2 is clogged.

FIG. 3 is a diagram showing a change in the threshold value A for determining whether the condenser 2 is clogged with a change in the evaporation temperature.
The threshold value A used for determining the clogging of the condenser 2 is such that the operation frequency of the compressor 1 is the maximum (hereinafter, also referred to as the maximum operation frequency) and the fan 6 Is a value set as a function of the evaporation temperature as shown in FIG. 3 with the maximum output (hereinafter also referred to as the maximum fan output) as a fixed condition.

FIG. 4 is a control flow for judging and reporting clogging of the condenser 2 by the refrigeration apparatus according to Embodiment 1 of the present invention.
Hereinafter, control for determining and reporting clogging of the condenser 2 by the refrigeration apparatus according to Embodiment 1 of the present invention will be described.
The time measuring unit 32 measures a time A from when the compressor 1 starts the steady operation (Step S1). Then, the determination unit 31 determines whether the time A has passed the first reference time (Step S2).

When the determination unit 31 determines that the time A has not passed the first reference time (No in step S2), the process returns to step S2 again.
On the other hand, when the determination unit 31 determines that the time A has passed the first reference time (Yes in step S2), the determination unit 31 determines the time A based on the frequency data of the compressor 1 controlled by the compressor control unit 33. Then, it is determined whether or not the operating frequency of the compressor 1 is the maximum (step S3).

When the determining unit 31 determines that the operating frequency of the compressor 1 is not the maximum (No in step S3), the process returns to step S2 again.
On the other hand, when the determining unit 31 determines that the operating frequency of the compressor 1 is the maximum (Yes in step S3), the determining unit 31 determines the fan frequency based on the output data of the fan 6 controlled by the fan control unit 34. It is determined whether or not the output of No. 6 is maximum (step S4).

When the determining unit 31 determines that the output of the fan 6 is not the maximum (No in step S4), the process returns to step S2 again.
On the other hand, when the determination unit 31 determines that the output of the fan 6 is the maximum (Yes in step S4), the pressure data acquisition unit 35 determines the pressure data on the suction side of the compressor 1 detected by the pressure detection unit 7. Is obtained (step S5). Then, the calculation unit 36 determines the evaporation temperature in the evaporator 5 from the pressure data on the suction side of the compressor 1 acquired by the pressure data acquisition unit 35, and sets a threshold A for clogging determination according to the evaporation temperature. (Step S6).

  After that, the temperature data acquisition unit 37 acquires the condensation temperature data and the outside air temperature data detected by the first temperature detection unit 8 and the second temperature detection unit 9, and the correction unit 38 converts the condensation temperature data and the outside air temperature data into the condensation temperature data and the outside air temperature data. The correction is performed using the correction data (step S7). Then, the calculation unit 36 calculates the temperature difference ΔT based on the corrected condensation temperature data and the outside air temperature data (Step S8).

  Then, the determination unit 31 determines whether or not the value of the temperature difference ΔT obtained in step S8 is larger than the threshold A obtained in step S6 (step S9).

When the determining unit 31 determines that the value of the temperature difference ΔT is not larger than the threshold value A (No in step S9), the process returns to step S2 again.
On the other hand, when the determining unit 31 determines that the value of the temperature difference ΔT is larger than the threshold A (Yes in step S9), the time measuring unit 32 measures the time B (step S10). Then, the determination unit 31 determines whether the time B has passed the second reference time (Step S11).

When the determination unit 31 determines that the time B has not passed the second reference time (No in step S11), the process returns to step S2 again.
On the other hand, when determining that the time B has passed the second reference time (Yes in step S11), the determining unit 31 determines that the condenser 2 is clogged.

  Then, when the determination unit 31 determines that the condenser 2 is clogged, the display unit control unit 39 notifies the display unit 11 that the condenser 2 is clogged (hereinafter, referred to as “condenser 2”). An instruction to perform clogging notification is issued (step S12). The clogging notification includes, for example, turning on an LED lamp provided on the display unit 11, or displaying an abnormality code on a 7-segment LED provided on the display unit 11.

  The setting of the second reference time in step S11 is appropriately changed according to the environmental operating conditions used, such as the specifications of the heat source unit 100 and the specifications of the load unit 200 connected to the heat source unit 100. be able to. Further, the specific value of each parameter for clogging determination may be determined by a test on an actual device, and the value of the threshold A may be estimated from the test result on the actual device and determined as a function of the evaporation temperature. .

  As described above, the refrigeration apparatus according to Embodiment 1 performs correction using the correction data on the condensation temperature data and the outside air temperature data detected by the first temperature detection unit 8 and the second temperature detection unit 9. Then, a temperature difference ΔT is obtained based on the corrected condensation temperature data and the outside air temperature data, and when the temperature difference ΔT is larger than the threshold value A, the clogging of the condenser 2 is determined. Give an instruction to notify of the blockage. Therefore, regardless of the detection error of the temperature detection unit, it is possible to obtain an effect that the clogging of the condenser 2 can be accurately determined and the occurrence of the clogging can be reported without being undetectable or causing erroneous detection.

  Further, by performing the clogging determination only at the maximum operating frequency and the maximum fan output at which the operation is relatively stable, the clogging of the condenser 2 can be more accurately determined without causing erroneous detection due to the operating conditions. .

  Further, by changing the threshold value A for determining clogging in accordance with the evaporation temperature, it is possible to determine whether the condenser 2 is clogged regardless of the use of the refrigerating apparatus, such as refrigeration use and freezing use.

  In the first embodiment, the condensation temperature data and the outside air temperature data detected by the first temperature detection unit 8 and the second temperature detection unit 9 are corrected using the correction data (Step S7 in FIG. 4). Although the embodiment has been described, the present invention is not limited thereto, and the first temperature detector 8 and the second temperature detector 9 may be corrected in advance. By doing so, the error of the first temperature detecting unit 8 and the second temperature detecting unit 9 itself is eliminated, so that the subsequent correction becomes unnecessary, and in that case, the processing of step S7 becomes unnecessary.

Embodiment 2 FIG.
Hereinafter, a second embodiment of the present invention will be described, but the description of the same parts as those in the first embodiment will be omitted, and the same or corresponding parts as in the first embodiment will be denoted by the same reference numerals.

  In the first embodiment, it is determined that the condenser 2 is clogged when the value of the temperature difference ΔT becomes larger than the threshold value A and the second reference time has elapsed. In the clogging determination method according to the first embodiment, it is necessary to calculate in advance correction data used when correcting the temperature data detected by the temperature detecting unit before performing the clogging determination. On the other hand, in the clogging determination method according to the second embodiment, the temperature difference ΔT and the temperature difference during initial operation (hereinafter, referred to as an initial temperature difference) ΔTo in which the clogging of the condenser 2 has not yet occurred are referred to as ΔTo. Use the difference between

  In the clogging determination method according to the second embodiment, the temperature difference ΔT can be obtained without using the correction data used when performing correction on the temperature data detected by the temperature detection unit as in the first embodiment. Can be corrected using the initial temperature difference ΔTo. Therefore, the influence of the detection error of the first temperature detector 8 and the second temperature detector 9 is ignored without calculating in advance the correction data used when correcting the temperature data detected by the temperature detector. can do.

  The temperature difference ΔT is a difference between the condensing temperature detected by the first temperature detecting unit 8 and the outside air temperature detected by the second temperature detecting unit 9, and the difference between the detection errors of the respective temperature detecting units is Larger values have a greater effect on the percentage of clogging that can be detected. On the other hand, clogging determination is performed using the difference between the temperature difference ΔT at the time of the determination and the initial temperature difference ΔTo at which the clogging ratio is 0% (= condensation temperature during the initial operation−outside air temperature during the initial operation). By doing so, the error in each of the temperature difference ΔT and the initial temperature difference ΔTo becomes the same. Therefore, the influence of the error can be ignored, and the clogging of the condenser 2 can be determined based on an index indicating how much the temperature difference ΔT has increased with respect to the initial temperature difference ΔTo. However, it is necessary to obtain the initial temperature difference ΔTo before performing the clogging determination.

FIG. 5 is a functional block diagram of a control device 30a of the refrigeration apparatus according to Embodiment 2 of the present invention.
The control device 30a according to the second embodiment includes a storage unit 40 that stores the value of the initial temperature difference ΔTo when the clogging of the condenser 2 is 0%, for example, during a trial run. In storing the value of the initial temperature difference ΔTo in the storage unit 40, it is necessary to match the operating conditions with the conditions at the time of clogging determination. That is, when the value of the initial temperature difference ΔTo is stored in a test operation or the like, the operation is temporarily performed at the maximum operation frequency and the maximum fan output, and the temperature data acquisition unit 37 acquires the condensation temperature data and the outside air temperature data at this time. Then, the calculation unit 36 calculates the value of the initial temperature difference ΔTo from the condensation temperature data acquired by the temperature data acquisition unit 37 and the outside air temperature data, and the storage unit 40 stores the value of the initial temperature difference ΔTo. It should be noted that the process of calculating the value of the initial temperature difference ΔTo is performed once and need not be performed thereafter.

FIG. 6 is a control flow for determining and notifying clogging of the condenser 2 by the refrigeration apparatus according to Embodiment 2 of the present invention.
Hereinafter, control for determining and reporting clogging of the condenser 2 by the refrigeration apparatus according to Embodiment 2 of the present invention will be described.
Steps S <b> 1 to S <b> 8 are the same as in the first embodiment, and a description thereof will not be repeated.
The determination unit 31 determines whether the difference between the value of the temperature difference ΔT obtained in step S8 and the value of the initial temperature difference ΔTo obtained in advance and stored in the storage unit 40 is larger than the threshold value A obtained in step S6. Is determined (step S13).

When the determining unit 31 determines that the difference between the value of the temperature difference ΔT and the value of the initial temperature difference ΔTo is not larger than the threshold A (No in step S13), the process returns to step S2 again.
On the other hand, when the determination unit 31 determines that the difference between the value of the temperature difference ΔT and the value of the initial temperature difference ΔTo is larger than the threshold A (Yes in step S13), the time measurement unit 32 measures the time B. (Step S10). Then, the determination unit 31 determines whether the time B has passed the second reference time (Step S11).

When the determination unit 31 determines that the time B has not passed the second reference time (No in step S11), the process returns to step S2 again.
On the other hand, when determining that the time B has passed the second reference time (Yes in step S11), the determining unit 31 determines that the condenser 2 is clogged.

  When the determination unit 31 determines that the condenser 2 is clogged, the display unit control unit 39 instructs the display unit 11 to notify that the condenser 2 is clogged. Is issued (step S12).

  In the second embodiment, the value of the threshold A is different from that of the first embodiment. However, the value of the threshold A is estimated from the test result of the actual device and determined as a function of the evaporation temperature, as in the first embodiment. Just do it.

  As described above, the refrigeration apparatus according to Embodiment 2 uses the initial temperature difference ΔTo obtained in advance to prevent clogging of the condenser 2 when the difference between the temperature difference ΔT and the initial temperature difference ΔTo is larger than the threshold value A. The determination is made, and an instruction to notify the clogging of the condenser 2 is issued to the display unit 11. Therefore, similarly to the first embodiment, regardless of the detection error of the temperature detection unit, the clogging of the condenser 2 is accurately determined without being undetectable or causing erroneous detection, and the occurrence of the clogging is notified. The effect that it can be obtained is obtained.

  Further, the first temperature detecting unit 8 and the second temperature detecting unit can be used without calculating the correction data used when correcting the temperature data detected by the temperature detecting unit as in the first embodiment. 9 can be neglected.

  Further, by performing the clogging determination only at the maximum operating frequency and the maximum fan output at which the operation is relatively stable, the clogging of the condenser 2 can be more accurately determined without causing erroneous detection due to the operating conditions. .

  Further, by changing the threshold A for clogging determination according to the evaporation temperature, clogging of the condenser 2 can be determined regardless of the use of the refrigerating apparatus such as refrigeration and freezing.

Embodiment 3 FIG.
Hereinafter, a third embodiment of the present invention will be described. However, description of parts overlapping with the first and second embodiments will be omitted, and the same or corresponding parts as those in the first and second embodiments will be denoted by the same reference numerals. .

  In the third embodiment, the threshold A used for clogging determination described in the first and second embodiments will be described. In the refrigerating apparatuses according to the first and second embodiments, before performing the clogging determination, a process for eliminating an influence of a detection error of the first temperature detecting unit 8 and the second temperature detecting unit 9 is performed in advance. The threshold value A is set on the assumption that the prior processing is performed. Therefore, in the refrigerating apparatuses according to the first and second embodiments, there is a possibility that an erroneous detection or a non-detection may occur when the prior processing is not performed. Therefore, in the refrigerating apparatus according to the third embodiment, a threshold value A corresponding to a case where the pre-processing is not performed is set.

  The threshold value A is determined from two values: (1) a clogging rate that does not cause an operation abnormality, for example, a temperature difference ΔT at 30%, and (2) a value that does not cause erroneous detection due to a detection error of the temperature detection unit. Regarding (1), a clogging rate that does not cause an operation abnormality, for example, a temperature difference ΔT at 30% may be obtained by an actual machine test. Regarding (2), it is necessary to set a value that does not determine that clogging has occurred due to a detection error of the temperature detection unit in an initial state where clogging of the condenser 2 has not occurred, and the maximum value of detection error + α (For example, 0.5K). By doing so, even if the temperature detection unit having the largest detection error is used, it is not determined that clogging of the condenser 2 has occurred unless α (for example, 0.5K) is clogged. Therefore, no erroneous detection occurs in the initial state.

  Note that the maximum value of the detection error is a value obtained from the specification value of the temperature detection unit to be used. α is desirably a value that causes clogging by at least 10%. (1) Similarly, α may be obtained by an actual machine test.

  As described above, in consideration of the possibility of erroneous detection, the threshold value A needs to be at least the value of (2). Therefore, as the threshold value A used in the control flow for determining the clogging of the condenser 2, the larger one of the values (1) and (2) may be selected.

  In addition, before the control flow for determining whether the condenser 2 is clogged, it is determined whether or not a process for eliminating a detection error of the temperature detection unit has been performed in advance, and if the process has been performed, the detection is performed. Erroneous detection due to errors does not occur. Therefore, by fixing the threshold value A to the value of (1), it is possible to perform clogging determination corresponding to the presence or absence of the prior processing.

  The process of changing the threshold value A to the fixed value of (1) depending on the presence or absence of the above-mentioned prior process may be automatically performed during a control flow for determining whether the condenser 2 is clogged, Before the control flow for determining clogging of the container 2 is performed, it may be performed manually.

  As described above, the refrigeration apparatus according to Embodiment 3 sets the threshold value A corresponding to the case where the pre-processing has not been performed, thereby enabling the temperature detection unit to detect the detection error of the temperature detection unit in Embodiments 1 and 2 in advance. Even when the process for eliminating the influence has not been performed, the clogging can be determined without causing erroneous detection. Further, by judging the presence or absence of the prior processing, if the prior processing has been performed, the same clogging determination as in the first and second embodiments can be performed. Thus, the effect that the clogging determination can be performed is obtained.

  Reference Signs List 1 compressor, 2 condenser, 3 receiver, 4 expansion valve, 5 evaporator, 6 fan, 7 pressure detector, 8 first temperature detector, 9 second temperature detector, 10 inverter board, 11 display unit , 20 on-site liquid extension pipe, 21 on-site gas extension pipe, 30 control unit, 30a control unit, 31 judgment unit, 32 hour measurement unit, 33 compressor control unit, 34 fan control unit, 35 pressure data acquisition unit, 36 calculation unit , 37 temperature data acquisition section, 38 correction section, 39 display section control section, 40 storage section, 100 heat source side unit, 200 load side unit.

Claims (11)

A heat source side unit including a compressor, a condenser including a fan, and a liquid receiver;
A load-side unit with an expansion valve and an evaporator;
The heat source-side unit and the load-side unit are connected by piping, the compressor, the condenser, the expansion valve, and a refrigerant circuit for sequentially circulating a refrigerant to the evaporator,
A control device for determining clogging of the condenser,
A first temperature detector for detecting a condensation temperature;
A second temperature detection unit that detects an outside air temperature,
The control device includes:
Using the temperature difference based on the condensation temperature and the outside air temperature detected by the first temperature detection unit and the second temperature detection unit and the threshold value A, it is determined whether the condenser is clogged. A determination unit that performs
The determination unit includes:
The clogging determination is performed when the output of the fan is the maximum ,
The threshold A is
Any one of a value larger than the maximum value of the detection error of the first temperature detection unit and the second temperature detection unit, and a difference between the condensation temperature and the outside air temperature at a clogging rate that does not cause an operation error. Refrigeration unit for which the value is set . The control device includes:
A temperature data acquisition unit that acquires data related to the condensation temperature and the outside air temperature detected by the first temperature detection unit and the second temperature detection unit;
A calculating unit that calculates a temperature difference that is a difference between the condensing temperature and the outside air temperature,
The refrigeration apparatus according to claim 1, wherein the determination unit determines that the condenser is clogged when the temperature difference is larger than a threshold value A. The control device includes:
A temperature data acquisition unit that acquires data related to the condensation temperature and the outside air temperature detected by the first temperature detection unit and the second temperature detection unit;
A calculation unit that calculates a temperature difference, which is a difference between the condensation temperature and the outside air temperature, obtained by the temperature data obtaining unit,
When the condenser is not clogged, an initial temperature difference, which is a difference between a condensation temperature detected by the first temperature detection unit and an outside air temperature detected by the second temperature detection unit, is stored. And a part,
The refrigeration apparatus according to claim 1, wherein the determination unit determines that the condenser is clogged when a difference between the temperature difference and the initial temperature difference is larger than a threshold value A. A display unit for reporting the clogging of the condenser,
The control device includes:
The display unit control unit that outputs an instruction to notify the clogging of the condenser to the display unit when the determining unit determines that the condenser is clogged. Refrigeration equipment. A pressure detection unit that detects a pressure on a suction side of the compressor,
The control device includes:
A pressure data acquisition unit that acquires pressure data on the suction side of the compressor detected by the pressure detection unit,
The refrigeration apparatus according to any one of claims 2 to 4, wherein the calculation unit obtains an evaporation temperature from a pressure on a suction side of the compressor, and sets the threshold value A according to the evaporation temperature. The refrigeration apparatus according to claim 5 , wherein the calculation unit sets the threshold value A according to the evaporation temperature, as a difference between the condensation temperature and the outside air temperature when the clogging rate is 30%. The determination unit includes:
The refrigeration apparatus according to any one of claims 1 to 6 , wherein the clogging determination is performed when an operation frequency of the compressor is maximum and an output of the fan is maximum. The control device includes:
Based on the condensation temperature and the outside air temperature detected by the first temperature detection unit and the second temperature detection unit, a temperature difference between them is calculated, the temperature difference is corrected, and the corrected temperature difference and a threshold A are calculated. The refrigeration apparatus according to any one of claims 1 to 7 , wherein it is determined whether or not clogging has occurred in the condenser using: The control device includes:
The refrigeration apparatus according to claim 8 , further comprising: a correction unit configured to correct the data related to the condensation temperature and the outside air temperature acquired by the temperature data acquisition unit using correction data obtained in advance. The refrigeration apparatus according to any one of claims 1 to 9 , wherein the first temperature detection unit and the second temperature detection unit are corrected in advance. The refrigeration apparatus according to any one of claims 6 to 10 , wherein the threshold value A is a threshold value for clogging determination determined according to the evaporation temperature in the evaporator.

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