JP2001133099A - Open showcase - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an open showcase wherein a preventive maintenance of a cooling system can be performed by sensing a frost on an evaporator, lowering of heat-exchanging performance of a condenser, leak of refrigerant gas, and dust attached on a honeycomb part by processing each sensor signal. SOLUTION: An abnormality monitoring/control device 3 determines causes of generation of abnormality by comparing a rate of change of each signal or the magnitude thereof with a predetermined threshold. The device 3 includes a means 31 for determining to switch condenser/evaporator from the rate of change in delivery side pressure signals, a sensing means 32 for sensing a lowering of condenser performance when the means 31 is on the side of a condenser 23, a means 33 for determining to switch honeycomb/evaporator when the means 31 is on the side of an evaporator 21, a sensing means 34 for sensing blocking of honeycomb when the means 33 is on the side of a honeycomb, a sensing means 35 for sensing a frost on an evaporator 21 when the means 33 is on the side of the evaporator 21, and a refrigerant leak sensing means 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an open showcase used in supermarkets, convenience stores, and the like, which detects an abnormality in a cooling system for cooling the inside of a refrigerator and facilitates preventive maintenance.

[0002]

2. Description of the Related Art FIG. 5 is a cross-sectional view of a separate type open showcase in which a refrigerator is separately provided as an example of an open showcase according to the prior art and the present invention. In FIG. 5, the open showcase 1 is provided with a large opening 13 on the front side for taking in and out of a product, a showcase body 10 having an air outlet 11 at an upper part of the opening 13 and a suction port 17 at a lower part. A display shelf 12 for a plurality of commodities, an evaporator 21 for cooling the inside of the showcase body 10 (inside 14), and a suction port 17 from a blowout port 11 through a duct 15 inside the showcase body 10. Blower 18 that circulates cooled air 19a, b, and c to form air curtain (19b) in large opening 13 and refrigerator 2 that is separately provided because it is a separately-installed open showcase in the illustrated example. And a refrigerant pipe 24 connecting between the refrigerator 2 and the evaporator 21.

In such a configuration, the open showcase 1 can easily take out a product from the large opening 13 in the front of the showcase body 10. But this opening
In order to prevent external heat from entering the inside of the showcase compartment 14 from the inside 13, the compartment 14 is cooled and an air curtain (19b) is formed. Cooling and air curtain (1
9b) can be formed as follows.

The high-temperature and high-pressure liquid refrigerant 26c produced by the compressor 22 and the condenser 23 of the refrigerator 2 passes through the refrigerant pipe 24, and is supplied to the low-temperature and low-pressure liquid by the expansion valve 25 shown by a dotted line in the open showcase 1. The refrigerant becomes the refrigerant 26d and is sent to the evaporator 21.
The air around the fins (21b to 21m) of the evaporator 21 that has been absorbed and cooled by the evaporation and vaporization of the liquid refrigerant 26d in the evaporator 21 is guided to the duct 15 by the blower 18, and the open showcase 1 Is sent to the warehouse 14 to cool the entire warehouse 14. Also, part of the cool air sent from the outlet 11
19b is sucked again by the blower 18 from the suction port 17,
The circulation of the cool air 19a, b, c is generated to form an air curtain to prevent outside air from entering the refrigerator. For the outlet 11 or the inlet 17 or the outlet 11 and the inlet 17 of the open showcase 1, a honeycomb having an excellent rectifying effect for facilitating formation of an air curtain is used.

Next, a monitoring / controlling temperature sensor installed in the main body 10 of the open showcase 1 will be described. T3 is a defrosting temperature sensor for detecting the temperature near the evaporator 21, T4 is a temperature control temperature sensor for detecting the temperature of the air guided to the duct 15 by the blower 18, and T5 is around the open showcase 1. An outside air temperature sensor for detecting a temperature (outside air), and T6 is an inside temperature sensor for detecting the temperature of the inside 14 of the open showcase 1.

Next, the configuration of the refrigerator 2 will be described.
The low-temperature and low-pressure gas refrigerant 26a sent from the evaporator 21 via the refrigerant pipe 24 is sent to the compressor 22 and becomes a high-temperature and high-pressure gas refrigerant 26b. After that, the gas refrigerant 26b is radiated by the condenser 23, so that the high-temperature and high-pressure liquid refrigerant 26b is discharged.
c is sent to the expansion valve 25 of the open showcase 1. Further, the temperature sensor and the pressure sensor installed in the refrigerator 2 will be described. T2 and P2 are a suction (low pressure) side temperature sensor and a suction (low pressure) side pressure sensor for measuring the temperature and pressure of the refrigerant gas 26a before entering the compressor 22, T1
And P1 are a discharge (high pressure) side temperature sensor and a discharge (high pressure) side pressure sensor for measuring the temperature and pressure after compression by the compressor 22. These sensors T1 to T6, P1,
P2 is used for temperature management and control of the open showcase 1.

[0007]

The open showcase and the cooling system of the refrigerator according to the prior art have four main causes of abnormalities as described below, which will cause future failures. For this reason, these abnormal factors need to be appropriately maintained and maintained before a future failure occurs. (1) Frost phenomenon of evaporator (ice bank) In an open showcase using a method in which an evaporator is provided in the refrigerator and air in the refrigerator is forcibly circulated, the frost on the evaporator generally decreases. When this occurs, clogging of the evaporator reduces the cooling capacity. For this reason, in the related art, a defrosting operation is periodically performed by a timer. The start of defrosting is started by a timer, and the end of defrosting is when the frost attached to the evaporator melts, the air circulates, and the temperature from the defrosting temperature sensor installed near the evaporator becomes higher than the set temperature. A way to quit is being taken.

However, in this method, defrosting may be terminated in a state where frost still remains in the evaporator. Even if the frost is small at first, the density increases while repeating the defrosting operation.
Even if defrosting, hardly melting frost gradually grows. In the meantime, the evaporator is completely clogged, so that the air does not circulate, resulting in a failure state in which the inside of the refrigerator is not cooled at all. (2) Clogging failure of the condenser of the refrigerator The high-temperature and high-pressure gas refrigerant compressed by the compressor is radiated by the condenser, so that the high-temperature and high-pressure gas refrigerant can be converted to the high-temperature and high-pressure liquid refrigerant. In an open showcase with such a refrigeration cycle, generally, if the condenser is clogged, the area of heat dissipation and heat transfer from the radiating fins inside the condenser to the outside decreases, and the heat exchange performance decreases. Finally, the high pressure pressure of the gas refrigerant becomes abnormal, and the refrigerator stops.

(3) Refrigerant gas leakage or refrigerant gas shortage failure If refrigerant gas circulating between the refrigerator and the showcase leaks or refrigerant gas shortage occurs, the cooling capacity is reduced and heat exchange in the evaporator is performed normally. Since it disappears, the temperature inside the showcase storage rises, and the inside of the storage becomes a failure state in which it does not cool down at all. (4) Clogging failure of the outlet (honeycomb part) of the showcase If the open showcase has been used for a long time, dust and dirt gradually accumulate in the outlet (hereinafter abbreviated as “honeycomb part”), and the honeycomb The part is clogged. For this reason, the circulation of the cooled air is deteriorated, and a failure state occurs in which the inside of the refrigerator is not cooled at all.

[0010] The present invention has been made in view of the above points, and an object of the present invention is to solve the above-mentioned problems and to provide a temperature signal from each temperature sensor installed in an open showcase and a refrigerator installed in a refrigerator. Based on the temperature signal from each temperature sensor and the pressure signal from the pressure sensor, four causes of abnormalities are as follows: (1) Adhesion of a certain amount of frost on the evaporator (2) Heat exchange performance of the condenser (3) Leakage or shortage of refrigerant gas in the refrigerator and showcase (4) Monitoring of cooling by adding a relatively small amount of dust and dust to the honeycomb part of the showcase by adding a relatively small sensor It is an object of the present invention to provide an open showcase that automatically detects system abnormalities, facilitates maintenance, and includes a cooling system preventive maintenance unit.

[0011]

In order to achieve the above object, the present invention connects a compressor, a condenser, and an evaporator to form a circulation system, and performs cooling by evaporating a refrigerant in the evaporator. A refrigerator, cooling means for storing the evaporator of the refrigerator in the main body, circulating cool air from the evaporator from the outlet to the inlet, forming an air curtain at the opening of the main body, and cooling the inside of the refrigerator;
In an open showcase that constitutes a cooling system that cools the interior of the refrigerator, an abnormality monitoring and control device that detects abnormalities in the cooling system and performs preventive maintenance uses a pressure on the discharge (high pressure) side of the compressor of the refrigerator. Or a sensor for measuring the temperature, a temperature control temperature sensor of the open showcase main body, and a temperature sensor in the refrigerator. Condenser / evaporator separation means for separating the abnormality determination on the side of the condenser, when the condenser / evaporator separation means is on the condenser side, a condenser performance decrease detection means for detecting a decrease in heat exchange performance of the condenser, When the evaporator separation means is on the evaporator / other side, honeycomb / evaporator disconnection separates the clogging of the honeycomb of the air curtain outlet and the abnormality judgment on the evaporator / other side from the rate of change of the temperature control temperature sensor signal. Minute means and this hani When the honeycomb / evaporator separation means is on the honeycomb side, the honeycomb clogging detection means for detecting honeycomb clogging, and when the honeycomb / evaporator separation means is on the evaporator / other side, the rate of change of the internal temperature sensor signal And a refrigerant gas leakage detecting means for detecting a refrigerant gas leakage abnormality from a temperature sensor signal in the refrigerator.

With this configuration, the four main causes of abnormalities in the cooling system are as follows:
(2) The heat exchange performance of the condenser deteriorates by a certain amount or more, (3) The refrigerant gas in the refrigerator and the showcase leaks or becomes insufficient, (4) A certain amount of dust and dust adheres to the honeycomb part of the showcase, Can be automatically detected. In addition, a compressor, a condenser, and an evaporator are connected to form a circulating system, and a refrigerator that evaporates and cools the refrigerant with the evaporator, and a refrigerator that accommodates the evaporator of the refrigerator in the main body and evaporates. Cooling means for circulating the cold air from the outlet to the inlet and forming an air curtain at the opening of the main body to cool the inside of the cabinet, and comprising a cooling system for cooling the inside of the cabinet. The abnormality monitoring / control device that detects system abnormalities and performs preventive maintenance is equipped with a sensor that measures the pressure or temperature on the discharge (high pressure) side of the compressor of the refrigerator. The pressure or temperature sensor signal on the discharge (high pressure) side Condenser / evaporator separation means for distinguishing the abnormality judgment of the condenser and the evaporator / other side from the rate of change of the condenser, and when the condensation / evaporator separation means is on the condenser side, the heat exchange performance of the condenser is reduced. Condenser / evaporation means for detecting deterioration of condenser performance When the separating means is on the evaporator / other side, the refrigerant for comparing the rate of change of the pressure or temperature sensor signal on the discharge (high pressure) side with the second threshold to separate the refrigerant leak from the abnormality determination on the evaporator / other side. Leakage / evaporator separation means, and when the refrigerant leakage / evaporator separation means is a refrigerant leak, detects refrigerant leakage, and when the refrigerant leakage / evaporator separation means is on the evaporator side, discharge (high pressure) side And evaporator frost detection means for detecting frost formation abnormality of the evaporator from the change rate of the pressure or temperature sensor signal.

With this configuration, the main causes of abnormalities in the cooling system, (1) frost adhered to the evaporator in a certain amount or more, (2) the heat exchange performance of the condenser decreased by a certain amount or more, (3) the refrigerator And the leakage or shortage of the refrigerant gas in the showcase can be automatically detected. In addition, a compressor, a condenser, and an evaporator are connected to form a circulating system, and a refrigerator that evaporates and cools the refrigerant with the evaporator, and a refrigerator that accommodates the evaporator of the refrigerator in the main body and evaporates. Cooling means for circulating the cold air from the outlet to the inlet and forming an air curtain at the opening of the main body to cool the inside of the refrigerator, and comprising a cooling system for cooling the inside of the refrigerator. An abnormality monitoring and control device that detects system abnormalities and performs preventive maintenance consists of a temperature sensor that measures the temperature of the discharge (high pressure) side of the compressor of the refrigerator, and a temperature sensor that measures the temperature of the suction (low pressure) side. , A temperature control temperature sensor of the open showcase main body and a temperature sensor in the refrigerator, and an evaporator / evaporator for separating an evaporator and a condenser / other side abnormality judgment from a change rate of a temperature sensor signal on a suction (low pressure) side.
When the condenser separating means and the evaporator / condenser separating means are on the evaporator side, the rate of change of the temperature sensor signal on the suction (low pressure) side and the rate of change of the temperature sensor signal on the discharge (high pressure) side are used. Heat exchange performance of the condenser based on the rate of change of the temperature sensor signal on the discharge (high pressure) side when the evaporator frost detection means and the evaporator / condenser separation means are on the condenser / other side. A condensing / refrigerant leakage separation unit that separates a decrease and an abnormality determination of the refrigerant gas leakage is provided.

[0014] With this configuration, the main causes of abnormalities in the cooling system, (1) a certain amount of frost adhered to the evaporator, (2) the heat exchange performance of the condenser decreased by a certain amount or more, (3) the refrigerator And the leakage or shortage of the refrigerant gas in the showcase can be automatically detected. In addition, a compressor, a condenser, and an evaporator are connected to form a circulating system, and a refrigerator that evaporates and cools the refrigerant with the evaporator, and a refrigerator that accommodates the evaporator of the refrigerator in the main body and evaporates. Cooling means for circulating the cold air from the outlet to the inlet and forming an air curtain at the opening of the main body to cool the inside of the refrigerator, and comprising a cooling system for cooling the inside of the refrigerator. An abnormality monitoring and control device that detects system abnormalities and performs preventive maintenance collects basic data when installing the refrigerator and data from the day after the installation, and measures the pressure on the discharge (high pressure) side of the compressor of the refrigerator. A pressure sensor, a temperature control temperature sensor for the open showcase body,
A condenser / evaporator separating means for separating a condenser, an evaporator, and an abnormality judgment on the other side from a change rate of a pressure sensor signal on a discharge (high pressure) side; When the separation means is on the condenser side, a condenser performance reduction detecting means for detecting a decrease in heat exchange performance of the condenser, and when the condensation / evaporator separation means is on the evaporator / other side, temperature control after defrosting. The time data required for the temperature to drop to the predetermined temperature is collected for one day, and the maximum deviation ΔT of the time data is compared with the basic data corrected by a predetermined coefficient, and the refrigerant gas leakage and the evaporator / Refrigerant leak / evaporator separating means for separating the abnormality determination on the other side, and refrigerant gas leak detecting the refrigerant gas leak when the refrigerant leak / evaporator separating means continuously detects the refrigerant gas leak side for a specified number of times. Detection means and refrigerant leakage / evaporator separation means are on the evaporator / other side When the time required for the internal temperature after defrosting to drop to the predetermined temperature is collected for one day, the maximum deviation ΔT 'of this time data is compared with the basic data corrected by the predetermined coefficient. Honeycomb / evaporator separating means for separating abnormality determination on the honeycomb and the evaporator side by performing
A honeycomb clogging detecting means for detecting honeycomb clogging when the honeycomb side has continued for a predetermined number of times, and comparing the rate of change of the internal temperature with basic data corrected by a predetermined coefficient to detect a frost formation abnormality. And evaporator frost detection means.

With this configuration, four main causes of abnormalities in the cooling system, (1) a certain amount of frost adheres to the evaporator,
(2) The heat exchange performance of the condenser deteriorates by a certain amount or more, (3) The refrigerant gas in the refrigerator and the showcase leaks or becomes insufficient, (4) A certain amount of dust and dust adheres to the honeycomb part of the showcase, Can be automatically detected. Further, an outside air temperature sensor can be provided.

With this configuration, when the honeycomb / evaporator separating means is on the evaporator / other side, the rate of change of the internal temperature sensor signal is calculated from the value of the rate of change of the outside air temperature sensor signal. Is corrected, and the frost formation abnormality of the evaporator can be detected. Further, the condensing / evaporator separating means includes a change rate calculating means for calculating a signal change rate per unit time of the pressure or temperature sensor signal on the discharge (high pressure) side, the change rate and a predetermined threshold value A. And comparing means for comparing

With this configuration, the condenser side can be selected when the change rate is equal to or larger than the threshold value A, and the evaporator / other side can be selected when the change rate is smaller than the threshold value A. Further, the condenser performance deterioration detecting means includes a comparing means for comparing the pressure or temperature sensor signal on the discharge (high pressure) side with a predetermined threshold value G, and a unit time of the pressure or temperature sensor signal on the discharge (high pressure) side. Comparing means for comparing the signal change rate per hit with a predetermined threshold value H.

With such a configuration, both comparing means can set the threshold values G,
When it is H or more, it is possible to detect a decrease in the heat exchange performance of the condenser. The honeycomb / evaporator separation means includes a change rate calculating means for calculating a signal change rate per unit time of the temperature control temperature sensor signal, and a change rate and a predetermined threshold value C.
And comparing means for comparing.

With this configuration, when the rate of change is smaller than the threshold C, the honeycomb clogging side can be selected, and when the rate of change is equal to or greater than the threshold C, the evaporator / other side can be selected. Further, the honeycomb clogging detecting means can include a comparing means for comparing the internal temperature sensor signal with a predetermined threshold value E. With this configuration, when the internal temperature is equal to or higher than the threshold value E, it is possible to detect honeycomb clogging of the outlet of the air curtain.

Further, the evaporator frost detection means may include a comparison means for comparing the rate of change of the internal temperature sensor signal with a predetermined threshold value D. With this configuration, when the rate of change is equal to or greater than the threshold value D, it is possible to detect frost formation abnormality of the evaporator. Further, the evaporator frost detection means includes a change rate calculation means for calculating a signal change rate per unit time of the outside air temperature sensor signal, and a correction calculation means for correcting a change rate of the internal temperature sensor signal by the change rate. Comparing means for comparing the correction value with a predetermined threshold value D.

With this configuration, when the correction value is equal to or larger than the threshold value D, it is possible to detect the frost formation abnormality of the evaporator. The evaporator frost detection means may include a correction database for correcting the rate of change of the internal temperature sensor signal based on the rate of change of the outside air temperature sensor signal. Further, the refrigerant gas leak detecting means may include a comparing means for comparing the internal temperature sensor signal with a predetermined threshold value F.

With this configuration, when the internal temperature is equal to or higher than the threshold value F, refrigerant gas leakage can be detected. Also,
The signal of the pressure or temperature sensor on the discharge (high pressure) side after defrosting is input in units of one day, and the condensing / evaporator separation means outputs the pressure or temperature sensor signal on the discharge (high pressure) side per unit time. A change rate calculating means for calculating a signal change rate (long term) and a comparing means for comparing the change rate with a predetermined threshold value H can be provided.

With this configuration, the condenser side can be selected when the change rate is equal to or larger than the threshold value H, and the evaporator / other side can be selected when the change rate is smaller than the threshold value H. Further, the condenser performance deterioration detecting means may include a comparing means for comparing a pressure or temperature sensor signal on the discharge (high pressure) side with a predetermined threshold value G. With this configuration, when the comparison unit is equal to or larger than the threshold value G, it is possible to detect a decrease in the heat exchange performance of the condenser.

The refrigerant gas leak detecting means is provided for detecting the rate of change (long term) of the pressure or temperature sensor signal on the discharge (high pressure) side.
And a comparing means for comparing a predetermined threshold value J with a predetermined threshold value J. With this configuration, when the rate of change (long term) is smaller than the threshold value J, refrigerant gas leakage can be detected.

Further, the evaporator frost detection means inputs a signal of the discharge (high pressure) side pressure or temperature sensor at intervals of defrosting, and outputs a signal of the discharge (high pressure) side pressure or temperature sensor signal. A comparison means for comparing the rate of change per unit time (short term) with a predetermined threshold K can be provided. With this configuration, when the change rate is smaller than the threshold K,
An frost formation abnormality of the evaporator can be detected.

Also, the signal of the temperature sensor on the discharge (high pressure) side and the signal of the temperature sensor on the suction (low pressure) side after defrosting are input on a daily basis. ) -Side temperature sensor signal, a change rate calculating means for calculating a signal change rate per unit time (long term), and a comparing means for comparing the change rate with a predetermined threshold A. .

With this configuration, the evaporator side can be selected when the change rate is equal to or larger than the threshold value A, and the condenser / other side can be selected when the change rate is smaller than the threshold value A. In addition, the evaporator frost detection means discharges at an interval between defrosting (high pressure).
Rate change means for inputting a temperature sensor signal on the suction side and a temperature sensor signal on the suction (low pressure) side and calculating a signal change rate (short term) per unit time of the temperature sensor signal on the suction (low pressure) side; A change rate calculating means for calculating a signal change rate (short term) per unit time of the temperature sensor signal on the (high pressure) side, and a comparing means for comparing both change rates with a predetermined threshold value K, respectively. Can be.

With this configuration, when both rates of change are smaller than the threshold value K, it is possible to detect the frost formation abnormality of the evaporator.
The condensing / refrigerant leakage separation means is configured to provide a signal change rate per unit time of the discharge (high pressure) side temperature sensor signal (long term).
And a comparing means for comparing the rate of change with a predetermined threshold value A.

With this configuration, when the rate of change is larger than the threshold value A, it is possible to detect a decrease in the heat exchange performance of the condenser, and when the rate of change is smaller than the threshold value A, it is possible to detect refrigerant gas leakage.
Further, the condensing / evaporator separating means includes a change rate calculating means for calculating a signal change rate per unit time of the pressure (high pressure) side pressure sensor signal, and a signal change rate per unit time of the internal temperature signal. A rate-of-change calculating means for calculating, and correction of a threshold (A5) obtained by correcting a signal rate-of-change basic data of a pressure sensor signal on a discharge (high pressure) side by a predetermined coefficient among basic data collected at the time of installing the refrigerator. Computing means.

With this configuration, when the rate of change is equal to or greater than the corrected threshold value (A5), the condensation side can be selected. Further, the condenser performance deterioration detecting means includes a comparing means for comparing the discharge (high pressure) side pressure sensor signal with a predetermined threshold value G, and a rate of change of the discharge (high pressure) side pressure sensor signal. And a comparing means for comparing with the threshold value H.

With this configuration, when both the rates of change are equal to or higher than the threshold G and the threshold H, respectively, it is possible to detect a decrease in the heat exchange performance of the condenser. In addition, the refrigerant leakage / evaporator separation means collects one day's worth of time data required for the temperature-controlled temperature after defrosting to drop to a predetermined temperature, and calculates the maximum value and the minimum value of this time data. A maximum deviation ΔT calculating means for measuring and calculating the difference and the maximum deviation ΔT, a correction calculating means for correcting basic data collected at the time of installing the refrigerator with a predetermined coefficient, and a maximum deviation ΔT calculating means and a correction calculating means. Comparing means for comparing both values.

With this configuration, when the measured data of the maximum deviation ΔT is equal to or larger than the basic data value corrected by the predetermined coefficient, the refrigerant gas leak side can be selected. Further, the refrigerant gas leak detecting means can detect the refrigerant gas leak abnormality when the refrigerant leak / evaporator separation means continuously selects the refrigerant gas leak side for a predetermined number of times.

Further, the honeycomb / evaporator separating means collects data for one day for the time required for the internal temperature after defrosting to drop to a predetermined temperature, and obtains the maximum value and the minimum value of the time data. A maximum deviation ΔT ′ calculating means for measuring and calculating the maximum deviation ΔT ′, a correction calculating means for correcting basic data collected at the time of installing the refrigerator with a predetermined coefficient, a maximum deviation ΔT calculating means, Comparison means for comparing both values of the correction calculation means.

With this configuration, when the maximum deviation ΔT ′ of the time data is equal to or greater than the basic data value corrected by a predetermined coefficient, the honeycomb side can be selected. Further, the honeycomb clogging detection means can detect the honeycomb clogging when the honeycomb / evaporator separation means continuously selects the honeycomb side for a predetermined predetermined number of times.

Further, the evaporator frost detection means includes a change rate calculating means for calculating a signal change rate per unit time of the internal temperature signal, and a change rate of the internal temperature signal of the basic data collected when the refrigerator is installed. A threshold (A5) for correcting the signal change rate basic data with a predetermined coefficient. With this configuration, when the rate of change of the internal temperature is larger than the basic data value corrected by the predetermined coefficient, it is possible to detect the frost formation abnormality of the evaporator.

The condenser performance deterioration detecting means can be provided with temperature sensors before and after the cooling fins of the condenser. With this configuration, it is possible to detect a clogging abnormality of the condenser from the temperature difference between the two sensors. In addition, the refrigerant gas leak detecting means can include a temperature sensor at a pipe portion at an entrance and exit of the evaporator.

With this configuration, the refrigerant gas leakage abnormality can be detected from the temperature difference between the two sensors. Also,
The refrigerant gas leak detecting means can include a pressure (or high pressure) side pressure or temperature sensor or a suction (low pressure) side pressure sensor. With this configuration, the refrigerant gas leakage abnormality can be detected from the variation width of the detection signal detected by any one of the sensors.

Further, the measurement data can be collected at night with little fluctuation in the surrounding environment. With this configuration, measurement data is stabilized by nighttime measurement with little change in the surrounding environment, so that detection accuracy can be improved and stable abnormality detection can be performed.

[0039]

FIG. 1 is a block diagram of an open-showcase abnormality monitoring / control device according to one embodiment of the present invention, and FIGS. 2 to 4 are open-showcase abnormality monitoring as another embodiment. 5 is a block diagram of the control device, FIG. 5 is a main part configuration diagram of the open showcase, FIG. 6 is an explanatory diagram of a main part configuration of the cooling fins of the evaporator and a state of frost formation, and FIG. Sensor, temperature control temperature sensor and temperature characteristic on the suction side of the compressor and time-dependent characteristic diagram of the detection signal of the pressure sensor,
FIG. 8 is a time-dependent characteristic diagram of the detection signal of the internal temperature sensor when the defrosting operation is started, FIG. 9 is an explanatory diagram of a main part configuration of the cooling fins of the condenser and an attached state of dust, and FIG. FIG. 11 is a time-dependent characteristic diagram of the detection signal of the temperature and pressure sensor on the discharge side of the compressor, and FIG. 11 is a time-dependent characteristic diagram of the detection signal of the pressure sensor on the discharge side due to clogging of the condenser and frosting / defrosting of the evaporator.
12 is a configuration diagram of a main part of a temperature sensor provided on the inflow side and the outflow side for cooling the cooling fins of the condenser, and FIG. 13 is a diagram showing detection signals of the temperature sensors provided on the inflow side and the outflow side of the condenser cooling fin. FIG. 14 is a time-dependent characteristic diagram of the detection signals of the pressure sensors on the suction side and the discharge side of the compressor when the refrigerant gas leaks or is insufficient. FIG. 16 is a characteristic diagram of a temperature control temperature with time, FIG. 16 is a detection signal characteristic diagram of a discharge side pressure sensor when refrigerant gas leaks or shortage occurs, and FIG. 17 is a chamber temperature when dust and dust adhere to the honeycomb portion. FIG. 18 is a graph showing the relationship between temperature in the refrigerator and the temperature in the state where dust and debris adhere to the honeycomb portion and defrosting operation is started. Flow chart of an abnormality detection algorithm of an abnormality monitoring / control device of an open showcase as an embodiment DOO, FIGS. 20 to 22 are flowcharts of the abnormality detection algorithm of the abnormality monitoring and control device as another embodiment. Hereinafter, FIG. (Embodiment 1) In FIG. 5, an open showcase 1 according to the present invention connects a compressor 22, a condenser 23, and an evaporator 21 to form a circulation system.
A refrigerator 2 for evaporating and cooling the evaporator 21 and an evaporator 21 of the refrigerator 2 are housed in the main body 10, and cool air 19 a from the evaporator 21 is circulated from the outlet 11 to the suction port 17, and Aperture
A cooling system for cooling the inside of the refrigerator 14 is provided by including an air curtain (19b) in the 13 and cooling means for cooling the inside of the refrigerator 14.

In FIG. 1, an abnormality monitoring / control device 3 for detecting an abnormality in the cooling system and performing preventive maintenance includes a sensor P1, which measures the pressure or temperature on the discharge (high pressure) side of the compressor 22 of the refrigerator 2 in FIG. T1 and a temperature control temperature sensor T4 of the open showcase body 10 and a temperature sensor T6 in the refrigerator. The condenser 23 evaporates from the discharge (high pressure) side pressure or the rate of change of the signals of the temperature sensors P1 and T1. Condenser / evaporator separating means 31 for separating the abnormality judgment of the condenser 21 / other side, and condensing for detecting a decrease in heat exchange performance of the condenser 23 when the condensing / evaporator separating means 31 is on the condenser 23 side. Vessel performance degradation detection means 32 and condenser / evaporator separation means
When 31 is the evaporator 21 / other side, the honeycomb / cylinder that separates the honeycomb clogging of the air curtain outlet 11 and the abnormality judgment of the evaporator 21 / other side from the rate of change of the temperature control temperature sensor signal T4.
Evaporator separating means 33 and the honeycomb / evaporator separating means 33
When is on the honeycomb side, the honeycomb clogging detection means 34 for detecting honeycomb clogging, and when the honeycomb / evaporator separation means 33 is on the evaporator 21 and the other side, evaporation is performed from the rate of change of the signal of the internal temperature sensor T6. Evaporator frost detection means 35 for detecting frost formation abnormality of the heater 21 and refrigerant gas leakage detection means 36 for detecting refrigerant gas leakage abnormality from the signal of the internal temperature sensor T6.

With this configuration, the four main causes of abnormalities in the cooling system are as follows: (1) when a certain amount or more of frost adheres to the evaporator 21, (2) the heat exchange performance of the condenser 23 decreases by a certain amount or more. (3) When the refrigerant gas 26 in the refrigerator 2 and the evaporator 21 of the showcase 1 leaks or runs short, (4) When a certain amount of dust or dust adheres to the honeycomb portion of the showcase 1, And automatically detect an abnormality. (Embodiment 2) In the open showcase 1, the compressor 22, the condenser 23 and the evaporator 21 are connected to form a circulation system, and the evaporator 21 evaporates and cools the low-temperature / low-pressure liquid refrigerant 26d. , And an evaporator 21 of the refrigerator 2 is housed in the main body 10, and cool air 19 a from the evaporator 21 is circulated from the outlet 11 to the suction port 17 and the air curtain is opened at the opening 13 of the main body 10. (1
9b) to form a cooling system that cools the inside of the refrigerator 14 by cooling the inside 14 of the refrigerator.

In FIG. 2, an abnormality monitoring / control device 4 for detecting an abnormality of the cooling system and performing preventive maintenance includes a sensor P1, which measures the pressure or temperature on the discharge (high pressure) side of the compressor 22 of the refrigerator 2 in FIG. A condenser / evaporator separation means 41 for separating the condenser 23 from the evaporator 21 and the other side based on the rate of change of the pressure of the discharge (high pressure) side or the signals of the temperature sensors P1 and T1; When the condenser / evaporator separation means 41 is on the condenser 23 side, the condenser
Condenser performance deterioration detection means for detecting 23 heat exchange performance deterioration
When the condenser / evaporator separating means 41 is located on the other side of the evaporator 21, the refrigerant on the discharge (high pressure) side or the rate of change of the signals of the temperature sensors P 1 and T 1 is compared with a second threshold value J 2. Leaks and evaporators
21. Refrigerant leak / evaporator separating means 43 for separating the abnormality determination on the other side, and when the refrigerant leak / evaporator separating means is a refrigerant leak, the refrigerant leak is detected and the refrigerant leak / evaporator separating means is detected. When 43 is the evaporator 21 side, there is provided evaporator frost detection means 44 for detecting frost formation abnormality of the evaporator 21 based on the discharge (high pressure) side pressure or the rate of change of the signals of the temperature sensors P1 and T1. Can be configured.

With this configuration, the main causes of abnormalities in the cooling system, (1) when a certain amount or more of frost adheres to the evaporator 21, and (2) when the heat exchange performance of the condenser 23 is reduced by a certain amount or more. (3) When the refrigerant gas in the refrigerator and the showcase leaks or runs short, the abnormality can be automatically detected by separating the refrigerant gas. (Embodiment 3) In the open showcase 1, the compressor 22, the condenser 23 and the evaporator 21 are connected to form a circulation system, and the evaporator 21 evaporates and cools the low-temperature / low-pressure liquid refrigerant 26d. , And the evaporator 21 of the refrigerator 2 are housed in the main body 10, and cool air 19 a from the evaporator 21 is circulated from the outlet 11 to the suction port 17, and an air curtain is formed at the opening 13 of the main body 10. (1
9b) to form a cooling system that cools the inside of the refrigerator 14 by cooling the inside 14 of the refrigerator.

An abnormality monitoring / control device 5 for detecting an abnormality in the cooling system and performing preventive maintenance is provided with a temperature sensor P for measuring the temperature on the discharge (high pressure) side of the compressor 22 of the refrigerator 2 in FIG.
1, T1 and temperature sensor P that measures the temperature of the suction (low pressure) side
2, T2, a temperature control temperature sensor T4 of the open showcase main body 11, and a temperature sensor T6 in the refrigerator. The evaporator 21 and the condenser 23 are provided based on the rate of change of the temperature sensor signal T2 on the suction (low pressure) side. Evaporator / condenser separating means 51 for separating the abnormality judgment on the side, and when the evaporator / condenser separating means 51 is on the evaporator 21, the rate of change and discharge of the signal of the temperature sensor T2 on the suction (low pressure) side When the evaporator frost detection means 52 detects the frost formation abnormality of the evaporator 21 from the change rate of the signal of the temperature sensor T1 on the (high pressure) side, and when the evaporator / condenser separation means 51 is on the condenser 23 / other side. , A condenser / refrigerant leakage separating means 53 for distinguishing the deterioration of the heat exchange performance of the condenser 23 and the abnormality determination of the refrigerant gas leakage from the rate of change of the signal of the temperature sensor T1 on the discharge (high pressure) side. Can be.

With this configuration, the main causes of abnormalities in the cooling system, (1) when a certain amount of frost adheres to the evaporator 21, and (2) when the heat exchange performance of the condenser 23 decreases by a certain amount or more. (3) When the refrigerant gas in the refrigerator and the showcase leaks or runs out, the abnormality can be automatically detected by isolating the refrigerant gas. (Embodiment 4) In the open showcase 1, the compressor 22, the condenser 23 and the evaporator 21 are connected to form a circulation system, and the evaporator 21 evaporates and cools the low-temperature / low-pressure liquid refrigerant 26d. , And an evaporator 21 of the refrigerator 2 is housed in the main body 10, and cool air 19 a from the evaporator 21 is circulated from the outlet 11 to the suction port 17 and the air curtain is opened at the opening 13 of the main body 10. (1
9b) to form a cooling system that cools the inside of the refrigerator 14 by cooling the inside 14 of the refrigerator.

The abnormality monitoring / control device 6 for detecting an abnormality in the cooling system and performing preventive maintenance collects basic data at the time of installation of the refrigerator 2 and data after the day after the installation in FIG. A pressure sensor P1 for measuring the pressure on the discharge (high pressure) side of the compressor 22, a temperature control temperature sensor T4 of the open showcase body 10, and a temperature sensor T6 in the refrigerator, and a pressure sensor on the discharge (high pressure) side From the rate of change of the signal of P1 and the basic data (threshold A5) collected at the time of installation of the refrigerator 2 corrected by the predetermined coefficient f1, the condenser 23 and the evaporator 21.
A condensing / evaporator separating means 61 for separating an abnormality judgment on the other side;
When the condenser / evaporator separating means 61 is on the side of the condenser 23, the condenser performance decrease detecting means 62 for detecting a decrease in the heat exchange performance of the condenser 23, and the condensing / evaporator dividing means 61 are connected to the evaporator 21 /. On the other side, confirm that there is no abnormality in the outside air temperature (T5), and save the time data required for the signal of the temperature control temperature sensor T4 after defrost to drop to the predetermined temperature F ° C for one day. The maximum deviation ΔT of the collected time data is corrected by a predetermined coefficient f3 and compared with the basic data (threshold M1) collected when the refrigerator 2 is installed. Refrigerant leakage / evaporator separation means 64 for separating the abnormality determination of the refrigerant, and a refrigerant for detecting the refrigerant gas leakage when the refrigerant leakage / evaporator separation means 64 continuously detects the refrigerant gas leakage side for a specified number of times n1. When the gas leak detection means 65 and the refrigerant leak / evaporator separation means 64 are on the evaporator 21 and the other side, the defrosted Inner temperature sensor T6 signal time data required for the drops to temperature K ° C a predetermined harvested 1 day maximum deviation ΔT of the time data '
And the time data required for the temperature control temperature sensor T4 to drop to the predetermined temperature F ° C is collected for one day, and compared with a value obtained by correcting the maximum deviation ΔT of the time data by a predetermined coefficient f4. Honeycomb / evaporator separation means 66 for separating abnormality determination between the honeycomb and the evaporator 21 side, honeycomb clogging detection means 67 for detecting honeycomb clogging when the honeycomb side continues for a specified number of times n2, and an internal temperature sensor Evaporator frost detection means for detecting a frost formation abnormality by comparing the rate of change of the signal of T6 with the basic data (threshold value D3) collected at the time of installation of the refrigerator 2 corrected by the predetermined coefficient f4. 68.

With this configuration, the four main causes of abnormalities in the cooling system are as follows: (1) When a certain amount or more of frost 21n adheres to the evaporator 21, (2) The heat exchange performance of the condenser 23 exceeds a certain amount (3) when the refrigerant gas in the refrigerator 2 and the showcase 1 leaks or runs out, and (4) when a certain amount of dust and dust 23n adhere to the honeycomb portion of the showcase 1. Abnormalities can be automatically detected.

[0048]

Embodiment 1 First, four causes of abnormalities and signal change characteristics of sensors installed in the open showcase 1 and the refrigerator 2 are described above, and Examples 2 to 5 are described above in Embodiments 1 to 4. The flowchart will be described. (Example 1) (1) Defrosting failure of evaporator 21 (ice bank) In FIG. 6, (A) of FIG. 6 is a perspective view showing a main configuration of the evaporator 21. It is composed of a refrigerant conduit 21A and cooling fins (21b to 21m). The low-temperature and low-pressure liquid refrigerant 26c is introduced inside the refrigerant conduit 21A, and the vaporized heat energy is absorbed from the cooling fins (21b to 21m) and is converted into the low-temperature and low-pressure gas refrigerant 26d.
The air around the cooling fins (21b to 21m) of the evaporator 21 can be cooled. FIG. 6B shows the evaporator 21 in a state where the frost 21n is completely removed, and FIG. 6C shows a state where a limit amount of frost 21n that can completely remove the frost by the defrosting operation is attached. Is shown in FIG.

In FIG. 7, the horizontal axis is the time axis, and the vertical axis is the temperature of the outside air temperature sensor T5 of the open showcase 1, the inside temperature sensor T6, and the temperature control temperature sensor T4. Illustrated. Here, time A indicates a state in which the frost 21n shown in FIG. 6B has been completely removed, and time B corresponds to FIG.
(C) of the limit amount of frost 21n that can remove the frost 21n shown in FIG.
Shows a state where is attached. The temperature detected by the outside air temperature sensor T5 is substantially the same as the ambient temperature irrespective of the adhesion of the frost 21n to the evaporator 21, and is constant. On the other hand, the temperatures detected by the in-compartment temperature sensor T6 and the temperature-regulated temperature sensor T4 gradually rise because the cold air 19a, b, c cannot be blown due to the attachment of the frost 21n to the evaporator 21.

At this time, as the frost 21n adheres to the evaporator 21, the heat transfer area of the cooling fins (21b to 21m) of the evaporator 21 decreases, and the heat exchange between the refrigerants 26c and 26d normally proceeds. Therefore, the temperature and pressure of the refrigerant 26a returning from the evaporator 21 to the refrigerator 2 decrease. Therefore, the suction (low pressure) side temperature sensor T2
And the sensor signal of the suction (low pressure) side pressure sensor P2 gradually decreases. FIG. 7B shows the suction (low pressure) side temperature sensor on the vertical axis.
The state of T2 is illustrated, and FIG. 7C illustrates the state of the suction (low pressure) side pressure sensor P2 on the vertical axis. Further, since the temperature and pressure on the suction (low pressure) side decrease, the sensor signals of the discharge (high pressure) side temperature sensor T1 and the discharge (high pressure) side pressure sensor P1 also gradually decrease.

Next, FIG. 8 is a diagram showing a temperature state of the in-compartment temperature sensor T6 in a state where a defrosting operation is performed. When much frost 21n does not adhere to the evaporator 21 (state 1)
Since the frost 21n is completely removed by the defrosting operation, the internal temperature (T6) temporarily increases by the defrosting operation, but rapidly decreases after the defrosting operation. However, frost 21n to evaporator 21
When a large amount of frost adheres (states 2 and 3), the frost 21n is not completely removed by the defrosting operation.
The evaporator 21 is clogged by the frost 21n, and it becomes difficult for the air to be cooled to circulate around the cooling fins (21b to 21m). become.

(2) Clogging of the condenser 23 of the refrigerator 2 In FIG. 9, the condenser 23 has a refrigerant conduit 23A and cooling fins (2
3b to 23m). A high-temperature and high-pressure gas refrigerant 26b obtained by compressing the refrigerant 26a by the compressor 22 is introduced into the refrigerant conduit 23A, and the heat energy of the gas refrigerant 26b is radiated from the cooling fins (23b to 23m) to form a high-temperature and high-pressure liquid refrigerant. Convert to 26c. FIG. 9A illustrates the condenser 23 in a state where the dust 23n is completely removed, and FIG. 9B illustrates the condenser 23 in a state where the dust 23n is clogged. The signal of the discharge (high pressure) side temperature sensor T1 of the refrigerator 1 at this time is shown in FIG.
The signal of the discharge (high pressure) side pressure sensor P1 is shown in FIG. In FIG. 10, time A is a state in which the dust 23n shown in FIG. 9A is not attached, and time B is a state in which the dust 23n shown in FIG. 9B is jammed.

Refrigerant gas temperature (T1) and pressure on the discharge (high pressure) side
(P1) (hereinafter, the temperature and pressure detected by the sensor in parentheses are abbreviated to the temperature and pressure detected by the sensor), the condenser 23 is clogged, the heat transfer area is reduced, and the heat release from the refrigerant gas 26b, c is reduced. Since the operation is not performed normally, the temperature rises according to the degree of clogging of the dust 23n. Refrigerant gas temperature (T
1) and the pressure (P1) increase, the temperature and pressure of the refrigerant 26d guided to the evaporator 21 also increase, so that the temperature of the showcase compartment 14 also increases and returns from the evaporator 21 to the refrigerator 2. The refrigerant gas temperature (T2) and pressure (P2) on the suction (low pressure) side also increase. And finally, the showcase 1 side is
Is not cooled at all, and the refrigerator 2 side also becomes abnormally high pressure, and the refrigerator 2 stops.

Next, in FIG. 11, the discharge (high pressure) when the clogging of the condenser 23 progresses and the frost occurs to some extent (not a failure) on the evaporator 21 of the showcase 1 is shown. The time-dependent characteristics of the pressure (P1) on the side are illustrated. Condenser 23
As the clogging progresses, the refrigerant gas pressure (P1) on the discharge (high pressure) side gradually increases, but the pressure (P1) acts in a direction to decrease due to the influence of frost 21n. The rate of change of the pressure (P1) on the discharge (high pressure) side decreases. But,
After the defrosting operation, the influence of the frost 21n is reduced, and the pressure becomes a value corresponding to the clogging of the condenser 23. Therefore, in order to detect the clogging of the condenser 23 in a state where the influence of the frost 21n is separated, a method of detecting the pressure (P1) after the defrosting operation is effective. This can be considered when considering the suction (low pressure) side refrigerant gas pressure (P2), or alternatively, the suction (low pressure) side temperature (T2) and the discharge (high pressure) side temperature (T1) instead of the pressures (P1, P2). The same temporal characteristics can be obtained even in the case of).

FIG. 12 shows the cooling fins (2
3b to 23m) is a configuration diagram in which temperature sensors T7 and T8 are installed on the air inflow side and the outflow side, and FIG. 13 illustrates the temperature state of the air inflow side temperature sensor T7 and the outflow side temperature sensor T8 at that time. It was done. The air flow F in the cooling fins (23b to 23m) is generated by a fan (23P) not shown here. When the condenser 23 is not clogged with the refuse 23n, the air inflow side temperature T7 and the outflow side temperature T8 become almost the same temperature, but as the clogging of the condenser 23 progresses, the air While the outflow side temperature T8 is almost the same as before the clogging, the outflow side temperature T8 decreases the heat transfer area due to the clogging, and the heat is not normally released, so the temperature of the refrigerant gas 26c does not decrease. Gradually rise. Therefore, as the clogging of the condenser 23 progresses, the temperature difference between the two increases.

(3) Phenomenon when refrigerant gas leaks or runs short FIG. 14 shows the state of pressure (P2, P1) on the suction (low pressure) side and discharge (high pressure) side when refrigerant gas 26c leaks or runs short. FIG. The discharge (high pressure) side pressure (P1) tends to increase at the initial refrigerant gas leakage, but decreases when the refrigerant gas leakage or shortage increases, because the compression effect in the compressor 22 decreases. On the other hand, suction (low pressure)
The side pressure (P2) gradually rises irrespective of the degree of leakage or shortage of the refrigerant gas, since heat exchange in the evaporator 21 proceeds excessively. The above is not only the pressure (P1, P2),
The same phenomenon occurs when considering the suction (low pressure) side temperature (T2) and the discharge (high pressure) side temperature (T1). Finally, since the cooling capacity of the evaporator 21 is reduced due to the leakage or shortage of the refrigerant gas, the inside of the showcase compartment 14 does not cool down.

Next, FIG. 15 illustrates the temperature characteristics of the internal temperature (T6) and the regulated temperature (T4) in the state where the defrosting operation has been started. In the condition where there is no leakage or shortage of refrigerant gas, the internal temperature (T6) and temperature control temperature increased by the defrosting operation
(T4) decreases rapidly after the defrosting operation. However, in a state where the refrigerant gas is leaked or insufficient, the cooling capacity of the evaporator 21 is reduced, so that after the defrosting operation, it takes time until the inside temperature (T6) and the temperature regulation temperature (T4) decrease. It becomes like this.

Next, FIG. 16 shows the fluctuation width of the signal of the pressure sensor P1 on the discharge (high pressure) side when the leakage or shortage of the refrigerant gas has progressed. In the state where there is no leakage or shortage of the refrigerant gas, if the product does not enter the showcase 1 very much or the product is taken in and out little and the load on the refrigerator 2 is light, the temperature control temperature (T4) fluctuates. Since the solenoid valve is opened and closed, the value of the signal of the pressure sensor P1 fluctuates greatly. However, in a state where the refrigerant gas leaks or runs short, the pressure P1 decreases, and the cooling capacity of the evaporator 21 also decreases. The fluctuation width becomes smaller. The above applies to the pressure sensor P2 on the suction (low pressure) side.
The same can be said for the signal of.

(4) Clogging of Honeycomb Part with Dust and Dust FIG. 17 shows that dust and dust 23 are formed in the outlet (honeycomb part) 11.
FIG. 3 illustrates the inside temperature (T6) and the regulated temperature (T4) of the showcase 1 when n adheres. If there is no dust or dust 23n attached to the outlet (honeycomb portion) 11, the temperature difference between the inside temperature (T6) and the temperature control temperature (T4) is about 5 ° C.
On the other hand, if dust or dust adheres to the outlet (honeycomb part) 11, the amount of air from the outlet (honeycomb part) 11 decreases, so that cool air does not reach the showcase compartment 14 and the temperature of the compartment 14 becomes lower. (T6) gradually rises. However, since the cool air reaches the inside of the duct 15 where the temperature control temperature sensor T4 is installed, the temperature control temperature (T4) is
Almost the same as before the attachment of n. Therefore, the internal temperature (T
The temperature difference between 6) and the temperature control temperature (T4) gradually increases as compared with before the attachment of dust and dust 23n. The above can be said to be the same even when considering not the temperature difference but the temperature ratio.

Next, FIG. 18 illustrates the temperature state of the internal temperature (T6) and the temperature control temperature (T4) in the state where the defrosting operation has been started. When there is no dust or dust 23n,
Internal temperature (T6) and temperature control temperature (T4) raised by defrosting operation
Decreases rapidly after the defrosting operation. However, when dust and dust 23n are attached, the air volume from the outlet (honeycomb part) 11 is reduced. The temperature is almost the same as the state without the adhesion of 23n, but the internal temperature (T6)
Takes a long time to decrease. The pressure (P1, P2) and temperature (T1, T1) on the discharge (high pressure) side and the suction (low pressure) side
T2) has dust and dust at the outlet (honeycomb) 11
When n is attached, it hardly changes. (Embodiment 2) Next, an embodiment of the cooling system abnormality detection algorithm described in Embodiment 1 will be described with reference to FIG. In FIG. 19, after the defrosting operation in step s1, the pressure signal (P1) on the discharge (high pressure) side is taken into the abnormality monitoring / control device 3. Next, based on the pressure information (P1) taken in step s2 and the pressure information (P1) taken before that, the rate of change of the discharge (high pressure) side pressure (P1) per unit time is calculated. calculate. When the rate of change is equal to or greater than the predetermined threshold value A1, the process proceeds to step s3, where the absolute value of the pressure signal (P1) on the ejection (high pressure) side is equal to or greater than the threshold value G1. When the rate of change of the pressure signal (P1) on the side is equal to or greater than the threshold value H1, it can be determined in step s5 that the heat exchange performance of the condenser 23 has decreased. The reason for taking in the pressure signal (P1) on the discharge (high pressure) side after the defrosting operation in this abnormality detection algorithm is to reduce the influence of the frost 21n of the evaporator 21 as described above. In addition, the threshold A1 and the threshold H1 used as the threshold of the change rate are such that the threshold A1 is a condition for separating the abnormal condition (for example, the evaporator 21 and others), whereas the threshold H1 is The purpose of the judgment is to judge a decrease in heat exchange performance, and the purpose of the judgment conditions is different. Normally, threshold H1
> Threshold A1, but in some cases, threshold H1 = threshold A1. Here, step s2 is shown in FIG.
Steps s3 and s4 correspond to the condenser performance degradation detecting means 32.

Next, in step s2, the discharge (high pressure) side pressure (P
When the rate of change of 1) is equal to or less than the predetermined threshold value A1, the process proceeds to step s11, and the temperature sensors installed in the showcase 1 are used to output the inside temperature information (T6), the temperature control temperature information (T4), and the outside air temperature. The temperature information (T5) is taken into the abnormality monitoring / control device 3. In step s12, when the absolute value of the outside air temperature (T5) is equal to or higher than the threshold value B1, it is determined that the ambient temperature of the showcase 1 (store temperature) is high for some reason (in this flowchart, the air conditioning temperature is the cause). Then, a warning is issued (step s21), and the flow advances to the next processing step s13. In step s12, the outside air temperature (T
When the absolute value of 5) is lower than the threshold value B1, it is normal, and the process similarly proceeds to the next processing step s13.

In step s13, the rate of change of the temperature control temperature (T4) is calculated. When the rate of change is equal to or greater than the threshold value C1, the evaporator 21 may be frosted 21n or leak refrigerant gas. Move to s14. Here, instead of using the rate of change of the controlled temperature (T4), the absolute value of the controlled temperature (T4) (shown in parentheses) may be used. In step s14, the rate of change between the inside temperature (T6) and the outside air temperature (T5) is calculated, and in step s15, based on the rate of change in the outside air temperature (T5), the correction value for the rate of change in the inside temperature (T6) is calculated. Is determined, and the internal temperature (T6) in step s16
Is corrected. The reason for the correction in this step (s14 to s16) is
This is to reduce the influence of the fluctuation of the outside air temperature (T5).
In addition, if the relationship between the correction rate of the change rate of the outside air temperature (T5) and the correction rate of the change rate of the internal temperature (T6) is stored in a database in advance, the arithmetic processing becomes easy. Internal temperature after correction in step s17 (T6)
Is greater than or equal to the threshold value D1, it can be determined that the frost 21n of the evaporator 21 is abnormal. Here, step s13 including steps s12 and s21 corresponds to the honeycomb / evaporator separation means 33, and step s17 including steps (s14 to s16) corresponds to the evaporator frost detection means 35.

If it is determined in step s17 that the temperature is smaller than the threshold value D1, the process further proceeds to step s25. If the absolute value of the internal temperature (T6) is equal to or greater than the threshold value F1, it can be determined that a refrigerant gas leak is abnormal. . This step s17 is the refrigerant gas leak detection means
Corresponds to 36. In step s13, the temperature control temperature (T
When the rate of change of 4) is smaller than the threshold value C1, the process proceeds to step s22. When the absolute value of the internal temperature (T6) is equal to or greater than the threshold value E1, the outlet (honeycomb portion) 11 of the showcase 1 has a predetermined amount or more. It can be determined that dust and dust 23n have adhered.
s22 corresponds to the honeycomb clogging detecting means 34.

In the description of the cooling system abnormality detection algorithm as an example of Embodiment 1 described above, the discharge (high pressure) side pressure signal (P1) is used.
Temperature signal on the discharge (high pressure) side instead of the pressure signal (P1) on the side
(T1) may be used. (Embodiment 3) Next, an embodiment of a cooling system abnormality detection algorithm described in Embodiment 2 will be described with reference to FIG. In FIG. 20, at step s31, about once a day, after the defrosting operation,
Abnormality monitoring and control device 4 for pressure signal (P1) on discharge (high pressure) side
Take in. Next, the pressure information (P
Based on 1) and the pressure information (P1) acquired before that, the change rate (for a long period) of the discharge (high pressure) side pressure (P1) per fixed time is calculated. When the rate of change is equal to or greater than the threshold value H2, the process proceeds to step s41. When the absolute value of the discharge (high pressure) side pressure (P1) is equal to or larger than the threshold value G2 in step s41, it can be determined in step s42 that the heat exchange performance of the condenser 23 is abnormally reduced. Here, steps s31 and s32 correspond to the condenser / evaporator separating means 41 of FIG. 2, and steps s41 and s42 correspond to the condenser performance deterioration detecting means.

On the other hand, at step s32, the discharge (high pressure) side pressure
When the change rate (long term) of (P1) is smaller than the threshold value H2, the process proceeds to step s33. When step s3
7, it can be determined that refrigerant gas leakage is abnormal. Here, step s33 corresponds to the refrigerant leakage / evaporator separation means 43.

In step s33, the discharge (high pressure) side pressure
When the rate of change (long term) of (P1) is equal to or greater than the threshold value J2, the process proceeds to step s34, and further, between one defrosting operation and the next defrosting operation, the pressure signal (high pressure) on the discharge (high pressure) side. P1) is taken into the abnormality monitoring / control device 4, and the process proceeds to step s35. In step s35, when the calculated change rate (short period) of the discharge (high pressure) side pressure (P1) per fixed time is equal to or smaller than the threshold value K1, it can be determined that the frost formation of the evaporator 21 is abnormal. Here, steps s34 and s35 correspond to the evaporator frost detection means 44.

In the description of the cooling system abnormality detection algorithm as an example of the second embodiment, the discharge (high pressure) side pressure signal (P1) has been described.
Temperature signal on the discharge (high pressure) side instead of the pressure signal (P1) on the side
(T1) may be used. (Embodiment 4) Next, an embodiment of the cooling system abnormality detection algorithm described in Embodiment 3 will be described with reference to FIG. In FIG. 21, after the defrosting operation at intervals of about one day in step s51,
The temperature signal (T1) on the discharge (high pressure) side and the temperature signal (T2) on the suction (low pressure) side are taken into the abnormality monitoring / control device 5, and the taken temperature information (T1), (T2) and Temperature information (T
1), based on the information (T2), the rate of change (long term) and suction (low pressure) of the discharge (high pressure) side temperature (T1) per fixed time
The change rate (long term) of the side temperature (T2) is calculated.

Next, based on the temperature information (T2) on the suction (low pressure) side taken in at step s52 and the temperature information (T2) on the suction (low pressure) side taken before that, a certain period of time is obtained. The change rate (long term) of the temperature information (T2) on the suction (low pressure) side per unit is calculated. When this change rate is smaller than the threshold value A3, step s5
Move to 3. In step s53, between one defrost operation and the next defrost operation, the temperature signals (T1) and (T2) on the discharge (high pressure) side and the suction (low pressure) side after the defrost operation are abnormally monitored. It is taken into the control device 5, and the rate of change of temperature per fixed time (short term) is calculated. Then, the process proceeds to step s54 where the rate of change of the temperature (T2) on the suction (low pressure) side is equal to or less than the threshold K3, and the rate of change of the temperature (T1) on the discharge (high pressure) side is also equal to or less than the threshold K4 in step s55. Thus, it can be determined that the frost formation of the evaporator 21 is abnormal. Here, steps s51 and s52 correspond to the evaporator / condenser separating means 51 of FIG. 3, and steps (s53 to s56) correspond to the evaporator frost detection means 52.

On the other hand, in step s52, the rate of change (long term) of the temperature signal (T2) on the suction (low pressure) side per fixed time is set to the threshold value.
If A3 or more, the process proceeds to step s61, and if the rate of change (long term) of the temperature signal (T1) on the discharge (high pressure) side per fixed time is longer than the threshold A4, the heat exchange performance of the condenser 23 decreases. It can be determined to be abnormal. Conversely, when the rate of change (long term) of the temperature signal (T1) on the discharge (high pressure) side per fixed time is smaller than the threshold value A4, it can be determined that the refrigerant gas is abnormal. Here, step s61 corresponds to the condensation / refrigerant leakage separation means 53. (Embodiment 5) Next, an embodiment of the cooling system abnormality detection algorithm described in Embodiment 4 will be described with reference to FIG. In FIG. 22, when the showcase 1 and the refrigerator 2 are newly installed in step s71, first, as reference data for a combination of the showcase 1 and the refrigerator 2, pressure information (discharge (high pressure) side pressure information ( P1), the inside temperature information (T6) of the showcase 1 and the temperature control temperature information (T4) are taken into the abnormality monitoring / control device 6, and after the defrosting operation, the temperature control temperature (T4) becomes F °.
The time T during which the temperature decreases to C, the time when the internal temperature (T6) decreases to K ° C, and the time when the regulated temperature (T4) decreases to K ° C are defined as reference values for one day at regular intervals. The data is taken into the abnormality monitoring / control device 6 as data. Then, in step s72, from the next day after the installation of the showcase 1 and the refrigerator 2, the pressure information (P1) on the discharge (high pressure) side, the inside temperature information (T6), the temperature control temperature information (T
4), the outside air temperature information (T5) is taken into the abnormality monitoring / control device 6, and after the defrosting operation, the time T during which the temperature control temperature (T4) decreases to F ° C, and the internal temperature (T6) The time at which the temperature decreases to K ° C and the time at which the regulated temperature (T4) decreases to K ° C are taken into the abnormality monitoring / control device 6 at regular intervals as one day's data, and the above-described step s71 is performed. The following abnormality judgment is performed by comparing with the reference data collected in the step.

First, in step s73, the rate of change of the internal temperature (T6) and the rate of change of the discharge (high pressure) side pressure (P1) are calculated from the measurement data collected in step s72. Step s7
In FIG. 3, the discharge (high pressure) side pressure (P1) is shown, but the discharge (high pressure) side temperature (T1) can also be determined in the same manner. Therefore, in the following steps (s74 to s76), the temperature (T1) is written in parentheses. Postscript for pressure (P1). The reference data described below is updated periodically (specifically, for example, the measurement data of the previous day is used as the reference data of the next day). The reference data may be based on data for one day or more. Of the measurement data captured in step s74, first, the discharge (high pressure) side pressure signal
The change rate of (P1) (or temperature (T1)) is calculated, and this change rate is based on the above-described reference data (for example, the measurement data of the previous day)
If the value is equal to or greater than a threshold value A5 obtained by multiplying by a predetermined coefficient f1, the process proceeds to step s75, and further discharge (high pressure) is performed in step s75.
The absolute value of the side pressure (P1) (or temperature (T1)) is equal to or greater than the threshold value G3, and in step s76, the change rate of the discharge (high pressure) side pressure (P1) (or temperature (T1)) is equal to or greater than the threshold value H3. When the condenser 23
Can be determined to be a heat exchange performance decrease abnormality. After this determination, the process proceeds to steps s91 and s92 in order to investigate whether another abnormality has occurred at the same time. Steps s91 and s92 perform the same determination processing as steps s81 and s82 described later.

On the other hand, when the rate of change of the discharge (high pressure) side pressure signal (P1) (or temperature (T1)) is smaller than the threshold value A5 in step s74, the process proceeds to step s81, and in step s81, the outside air temperature (T5) Showcase 1 when the absolute value is greater than or equal to threshold B1
It is determined that the ambient temperature (in-store temperature) is high for some reason (in this flowchart, the air-conditioning temperature is the cause), a warning is issued in step s82, and the process proceeds to the next step s83. When the absolute value of the outside air temperature (T5) is smaller than the threshold value B1 in step s81, the outside air temperature (T5) is normal, and the process similarly proceeds to step s83.

Next, in step s83, one day's data of the time T during which the regulated temperature drops to F ° C after defrosting, which is taken in as measurement data, is read. In step s84, the data of this one day is read. Of the data, the maximum time Tmax and the minimum time Tmin
Is calculated.

[0073]

ΔT = Tmax−Tmin (1) When the time difference ΔT is equal to or larger than the threshold value M1 obtained by multiplying the above-mentioned reference data (for example, the time difference ΔT measured on the previous day) by a constant f3 in step s85, Proceeding to step s86, when such a phenomenon has continued for the specified number of times n1, it is determined that a refrigerant gas leak is abnormal, and the flow proceeds to the next step s93. The reason why the time difference ΔT is used in this determination process is to prevent the dispersion of the determination due to the difference in the surrounding environment such as day and night, and to make it more reliable to distinguish from other failures.

When the time difference ΔT is smaller than the threshold value M1 in step s85, after the judgment of the refrigerant gas leak failure in step s87, and after the judgment of the decrease in the heat exchange performance of the condenser 23 in step s77, the process proceeds to step s93. In step s93, after defrosting, a predetermined coefficient is set for the time when the inside temperature (T6) decreases to K ° C and the time when the temperature-regulated temperature (T4) decreases to K ° C.
Comparing the threshold value multiplied by f4, the time during which the internal temperature (T6) decreases to K ° C is determined by the coefficient f4
If the multiplied value is equal to or more than the threshold value, the process proceeds to step s96. If such a phenomenon continues for a specified number of times n2 in step s94, a certain amount or more of dust and dust 23n It can be determined that it has adhered.

In step s93, the internal temperature (T6) is K °
When the temperature controlled temperature (T4) during which the temperature decreases to C is smaller than a threshold obtained by multiplying the temperature control temperature (T4) by the coefficient f4, the rate of change of the internal temperature (T6) is determined in step s94. ,
Abnormality of frost formation of the evaporator 21 can be determined when the difference is equal to or more than the threshold value D3 obtained by multiplying the internal temperature (change rate of the inside temperature (T6) measured on the previous day) by a predetermined coefficient f2.

Steps (s71 to s74) are performed by the condenser / evaporator separating means 61 of FIG. 4, steps (s75 to s77) are performed by the condenser performance deterioration detecting means 62, and steps (s83 to s85) are performed by the refrigerant. leakage/
Steps s86 and s87 are to the refrigerant gas leak detection means 65, step s93 is to the honeycomb / evaporator separation means 66, step s94 is to the honeycomb clogging detection means 67, and step s96 is the evaporator separation means 64. Corresponds to the frost detection means 68. (Embodiment 6) Each cutting means and detecting means described in the first and second embodiments will be described below. 1 and 19
The abnormality monitoring / control device 3 for detecting an abnormality in the cooling system of the open showcase 1 and performing preventive maintenance includes a temperature control temperature sensor T4 of the showcase body 10 and a temperature sensor T6 in the refrigerator.
And a pressure or temperature sensor on the discharge (high pressure) side of the refrigerator 2
P1 and T1. According to the signals from these sensors, the condensing / evaporator separating means shown in FIG.
31 is the pressure (P1) on the discharge (high pressure) side in step s2 of FIG.
Alternatively, it can be provided with a change rate calculating means for calculating a signal change rate per unit time of the temperature sensor signal (T1), and a comparing means for comparing the change rate with a predetermined threshold A (A1). . Here, for example, when processing is performed by software, the change rate calculating means can be executed by dividing the difference value of data at two measurement points by the time difference.

With this configuration, when the change rate is equal to or larger than the threshold value A (A1), the condenser 23 is selected, and when the change rate is smaller than the threshold value A (A1), the evaporator / other side is selected. Detection processing can be separated. Further, the condenser performance deterioration detecting means 32 includes a comparing means for comparing the pressure (P1) or the temperature sensor signal (T1) on the discharge (high pressure) side with a predetermined threshold value G (G1) in step s3, s4, comparing means for comparing a signal change rate per unit time of the pressure (P1) or temperature sensor signal (T1) on the discharge (high pressure) side with a predetermined threshold value H (H1). it can.

According to this configuration, both comparing means can set the threshold value G (G
1) When H (H1) or more, it is possible to detect an abnormality in the heat exchange performance of the condenser 23. In step s13, the honeycomb / evaporator separation means 33 outputs the temperature control temperature sensor signal (T4).
And a comparing means for comparing the change rate with a predetermined threshold value C (C1).

With this configuration, when the change rate is smaller than the threshold value C (C1), the honeycomb clogging side is selected, and when the change rate is equal to or larger than the threshold value C (C1), the evaporator / other side is selected. Detection processing can be separated. Further, the honeycomb clogging detecting means 34 can include a comparing means for comparing the inside temperature sensor signal (T6) with a predetermined threshold value E (E1) in step s23.

With this configuration, the internal temperature (T6) becomes equal to the threshold E (E
1) Above, it is possible to detect an abnormality of honeycomb clogging of the air outlet 11 of the air curtain. Further, the evaporator frost detection means 35, a comparison means for comparing the rate of change of the in-chamber temperature sensor signal (T6) calculated in step s14 and a threshold value D (D1) predetermined in step s14, Can be provided.

With this configuration, when the rate of change is equal to or greater than the threshold value D (1), it is possible to detect an abnormality in frost formation on the evaporator 21. In addition, by providing the outside air temperature sensor signal T5,
The evaporator frost detection means 35 further includes a change rate calculating means for calculating a signal change rate per unit time of the outside air temperature sensor signal (T5) in step s14, and an internal temperature sensor in steps s15 and s16 based on the change rate. Correction calculation means for correcting the rate of change of the signal (T6) and comparison means for comparing the correction value with a predetermined threshold value D (D1) in step s17 can be provided.

With this configuration, when the correction value is equal to or larger than the threshold value D (D1), it is possible to detect an abnormality of frost formation on the evaporator 21. Further, the evaporator frost detection means 35 stores correction data for correcting the rate of change of the internal temperature sensor signal (T6) based on the rate of change of the outside air temperature sensor signal (T5) as a database in the memory of the abnormality monitoring / control device 3 as a database. Can be prepared.

Further, the refrigerant gas leak detecting means 36 can include a comparing means for comparing the internal temperature sensor signal (T6) with a predetermined threshold value F (F1) in step s25. With this configuration, when the internal temperature (T6) is equal to or higher than the threshold value F (F1), it is possible to detect an abnormality in refrigerant gas leakage. As a result, the provision of the outside air temperature sensor signal T5 makes it possible to further distinguish the refrigerant gas leak failure (step s25) in which the pressure signal (P1) on the discharge side of the refrigerator 2 and the temperature (T1) tend to have the same tendency. It becomes possible precisely, and the detection accuracy of frost formation on the evaporator 21 can be improved. (Embodiment 7) Each cutting means and detecting means described in the second and third embodiments will be described below. FIG. 2 and FIG.
, An abnormality monitoring / control device 4 for detecting an abnormality of a cooling system of the open showcase 1 and performing preventive maintenance includes a refrigerator 2
After the defrosting operation of the signals from the discharge (high pressure) side pressure or temperature sensors P1 and T1 in step s31d of FIG. Input at the timing of.

The condensing / evaporator separating means 41 shown in FIG.
Is a change rate calculating means for calculating a signal change rate (long term) per unit time of the pressure (P1) or temperature sensor signal (T1) on the discharge (high pressure) side in step s32 of FIG. Comparing means for comparing with a predetermined threshold value H (H2). With this configuration, the rate of change is the threshold H
(H2) or more, the condenser 23 side is selected, and the rate of change is the threshold value H (H
2) If smaller, the abnormality detection process can be separated by selecting the evaporator / other side.

In step s41, the condenser performance deterioration detecting means 42 compares the pressure (P1) or temperature sensor signal (T1) on the discharge (high pressure) side with a predetermined threshold value G (G2). And can be provided. With this configuration, when the comparison means is equal to or larger than the threshold value G (G2), it is possible to detect an abnormality in the heat exchange performance of the condenser 23.

In step s33, the refrigerant leakage / evaporator separation means 43 determines whether the change rate (long term) of the pressure (P1) or the temperature sensor signal (T1) on the discharge (high pressure) side is a predetermined threshold value. J (J2). With this configuration, the rate of change (long term) is
When the value is smaller than (J2), an abnormality of refrigerant gas leakage can be detected.

Further, the evaporator frost formation detecting means 44
At s34, the pressure on the discharge (high pressure) side (P
1) or the temperature sensor signal (T1), and in step s35, the pressure (P1) or temperature sensor signal (T1)
A comparison means for comparing the rate of change per unit time (short period) of 1) with a predetermined threshold K (K1) can be provided. Here, the threshold values, for example, H2, G2 and K1 are collected every day or every few days (long term) and at a predetermined interval between defrosting and defrosting (short term) ) Thresholds for the data are distinguished by numbers 2 and 1.

With this configuration, when the rate of change is smaller than the threshold value K (K1), it is possible to detect an abnormality in frost formation on the evaporator 21. (Embodiment 8) Each cutting means and detecting means described in the third and fourth embodiments will be described below. 3 and FIG.
, The abnormality monitoring and control device 5 for detecting an abnormality in the cooling system of the open showcase 1 and performing preventive maintenance includes a refrigerator 2
, A temperature sensor T2 on the suction (low pressure) side and a temperature sensor T1 on the discharge (high pressure) side. In response to signals from these sensors, the abnormality monitoring / control device 5 shown in FIG. 3 performs a temperature measurement on the discharge (high pressure) side temperature sensor T1 and suction (low pressure ) Input the signal from the temperature sensor T2. And step
In s52, the evaporating / condenser separating means 51 calculates the change rate (long term) of the signal rate per unit time (long term) of the temperature sensor signal (T2) on the suction (low pressure) side. Comparing means for comparing with a predetermined threshold value A (A3).

With this configuration, the side of the evaporator 21 is selected when the change rate is equal to or larger than the threshold value A (A3), and when the change rate is smaller than the threshold value A (A3), the condenser / other side is selected. Abnormality detection processing can be separated. Also, evaporator frost detection means
In step s53, a temperature sensor signal (T1) on the discharge (high pressure) side and a temperature sensor signal (T2) on the suction (low pressure) side are input at intervals of defrosting in step s53, and suction (low pressure) is performed in step s54. Change rate calculating means for calculating a signal change rate (short period) per unit time of the temperature sensor signal (T2) on the side of), comparing means for comparing the change rate with a predetermined threshold value K (K3),
At step s55, a change rate calculating means for calculating a signal change rate (short period) per unit time of the temperature sensor signal (T1) on the discharge (high pressure) side, and a predetermined threshold value K (K4)
And comparing means for comparing with.

With this configuration, step s54 and step
s55 and the threshold value K at which both rates of change correspond to both comparison means
When it is smaller than (K3) and (K4), it is possible to detect an abnormality of frost formation on the evaporator 21. Also, the condensation / refrigerant leakage separation means 53
Is the temperature sensor signal on the discharge (high pressure) side in step s61.
A change rate calculating means for calculating a signal change rate (long term) per unit time of (T1), and a comparing means for comparing the change rate with a predetermined threshold A (A4) can be provided.

With this configuration, the rate of change is equal to the threshold value A (A4).
When it is larger, it is possible to detect an abnormality in the heat exchange performance of the condenser 23, and when this change rate is smaller than the threshold value A (A4), it is possible to detect an abnormality in refrigerant gas leakage of the evaporator 21. . (Embodiment 9) Each cutting unit and detecting unit described in the fourth and fifth embodiments will be described below. FIG. 4 and FIG.
, The abnormality monitoring and control device 6 for detecting an abnormality of the cooling system of the open showcase 1 and performing preventive maintenance includes a temperature control temperature sensor T4 of the showcase body 10 and a temperature sensor T6 in the refrigerator.
And an outside air temperature sensor T5 and a pressure sensor P1 on the discharge (high pressure) side of the refrigerator 2. Based on signals from these sensors, the abnormality monitoring / control device 6 shown in FIG. 4 uses the following data as basic data when the refrigerator 2 of the open showcase 1 is installed in step s71 of FIG. Collect and store in memory. That is, the compressor
In the defrosting operation, the defrosting operation is stopped for each of the pressure value (P1) of the pressure sensor P1 on the discharge (high pressure) side of 22, and the inside temperature (T6) and the regulated temperature (T4) of the showcase 1. The time during which the subsequent temperature drops to a predetermined F ° C. or K ° C. is measured, and this measurement data is stored in a memory.

Next, from the next day after the installation of the refrigerator 2, in step s72 as operation start initial data, the above-mentioned step s71
Collect the basic data and data on the outside air temperature (T5) at that time. In step s73, the condensing / evaporator separating means 61 calculates a change rate calculating means for calculating a signal change rate per unit time of the discharge (high pressure) side pressure sensor signal (P1) (or temperature (T1)). A change rate calculating means for calculating a signal change rate per unit time of the internal temperature signal (T6). In step s74, the pressure sensor on the discharge (high pressure) side of the basic data collected when the refrigerator is installed. Signal (P19) (or temperature
(T1)) the signal change rate basic data is determined by a predetermined coefficient f1.
Correction calculation means for the threshold value (A5) corrected in step (a).

With this configuration, in step s74, the calculated pressure sensor signal (P1) on the discharge (high pressure) side (or the temperature
(T1)) is a threshold value obtained by correcting the data by the coefficient f1 among the basic data previously collected and held in step s71.
(A5) In the above case, the abnormality detection processing can be separated by selecting the condenser 23 side. In step s75, the condenser performance deterioration detecting means 62 determines the pressure sensor signal (P1) (or temperature (T1)) on the discharge (high pressure) side and a predetermined threshold value G.
(G3) and a comparison of comparing the rate of change of the pressure sensor signal (P1) (or temperature (T1)) on the discharge (high pressure) side with a predetermined threshold value H (H3) in step s76. Means,
Can be provided.

With this configuration, in step s77, when both the comparison results of the comparison means in step s75 and the comparison means in step s76 are equal to or larger than the threshold values G (G3) and H (H3), the condenser 23
Can be detected when the heat exchange performance is reduced. As a result, the influence of the ambient environment change due to day or night or season can be reduced, and the accuracy of detecting a decrease in heat exchange performance due to clogging of the condenser 23 can be improved.

The outside air temperature abnormality confirming means 63 compares the outside air temperature (T5) with a predetermined threshold value B1 in step s81 or step s91, and proceeds to step s82 or step s92.
When the value is equal to or more than the threshold value HB3, an abnormality in the outside air temperature (T5) can be confirmed. That is, for example, it is possible to determine that the temperature in the store is high due to inappropriate setting temperature of the air conditioner or the like, and it is possible to distinguish between an abnormality or a failure in the open showcase 1 and the refrigerator 2.

In step s83, the refrigerant leakage / evaporator separation means 64 stores the time data required for the temperature control temperature (T4) after the defrosting operation to drop to the predetermined temperature F ° C for one day. In step s84, the difference between the maximum value and the minimum value of the time data, that is, the maximum deviation ΔT calculating means for measuring and calculating the maximum deviation ΔT, and in step s85, the maximum deviation ΔT is collected when the refrigerator 2 is installed. It is possible to include a correction operation means for correcting the ΔT basic data by a predetermined coefficient f3, and a comparison means for comparing both values of the maximum deviation ΔT operation means and the correction operation means.

With this configuration, when the measured data of the maximum deviation ΔT is equal to or more than the basic data value corrected by the predetermined coefficient f3 in step s85, the side of the refrigerant gas leak is selected to perform the abnormality detection processing. Can be separated.
Further, the refrigerant gas leakage detecting means 65 detects the refrigerant gas leakage abnormality when the refrigerant leakage / evaporator separation means 64 selects the refrigerant gas leakage side continuously for a predetermined number of times n1 in step s85. Can be detected. As a result, an appropriate measure can be taken by the user or the serviceman before the interior 14 becomes a failure state in which the refrigerator 14 does not cool down at all.

In step s93, the honeycomb / evaporator separating means 66 calculates time data required for the internal temperature (T6) after the defrosting operation to drop to the predetermined temperature K ° C for one day. The difference between the maximum value and the minimum value of the time data, that is, the maximum deviation ΔT ′ calculating means for measuring and calculating the maximum deviation ΔT ′, and the temperature control temperature (T4) after the defrosting operation are predetermined. And a maximum deviation ΔT ”calculating means for measuring and calculating a difference between a maximum value and a minimum value of the time data, that is, a maximum deviation ΔT", for one day of time data required for the temperature to drop to the temperature K ° C. ,
The maximum deviation ΔT "of this temperature control temperature (T4) is determined by a predetermined coefficient.
and a comparing means for comparing both the maximum deviation ΔT ′ of the internal temperature (T6) and the corrected maximum deviation ΔT ”of the regulated temperature (T4). .

With this configuration, when the maximum deviation ΔT ′ of the internal temperature (T6) is equal to or larger than the maximum deviation ΔT ″ of the temperature-regulated temperature (T4) corrected by the predetermined coefficient f4, the honeycomb side is selected. As a result, the outlet of the showcase (honeycomb part) has the same tendency as that of the internal temperature (T6) abnormality due to the refrigerant gas leakage abnormality.
The clogging of the honeycomb 11 can be separated, and the detection accuracy of the clogging of the honeycomb 11 can be improved.

Further, the honeycomb clogging detecting means 67 detects when the honeycomb / evaporator separating means 66 in step s93 selects the honeycomb side continuously for a predetermined specified number of times n2.
In step s93, an abnormality of honeycomb clogging can be detected. Further, in step s96, the evaporator frost detection means 68 calculates the signal change rate per unit time of the internal temperature signal (T6), and the change rate calculation means described above in step s71.
The basic coefficient of the signal change rate of the internal temperature signal (T6) among the basic data collected when installing the refrigerator in
correction calculation means for the threshold value (D3) corrected by f2.

With this configuration, when the rate of change of the internal temperature (T6) is equal to or greater than (smaller than) the basic data value corrected by the predetermined coefficient f2, an abnormality in frost formation on the evaporator 21 is detected. be able to. (Embodiment 10) Further, the condenser performance deterioration detecting means 32, 42, (5
3), 62, temperature sensors T7, T8 can be provided before and after the cooling fins of the condenser 23 in FIG.

With this configuration, it is possible to detect an abnormal clogging of the condenser 23 from the temperature difference between the two sensors T7 and T8. Also, refrigerant gas leak detection means 36, (43), (53), 65
Can be provided with a temperature sensor not shown in FIG. 5 in the piping section at the entrance and exit of the evaporator 21. With this configuration, it is possible to detect the refrigerant gas leakage abnormality from the temperature difference between the two sensors.

The refrigerant gas leak detecting means 36, (43), (5
3) and 65 are the pressure (P1) on the discharge (high pressure) side or the temperature sensor (T1) or the pressure (P2) on the suction (low pressure) side in FIG.
Alternatively, a temperature sensor (T2) can be provided. With this configuration, a refrigerant gas leakage abnormality can be detected from the variation width of the detection signal detected by any of the sensors (P1, T1, P2, T2).

It is preferable that the measurement data is collected at night when there is little fluctuation in the surrounding environment. With this configuration, measurement is performed at night when there is little change in the surrounding environment, so that the measurement data is stabilized, so that detection accuracy can be improved and stable abnormality detection can be performed.

[0105]

As described above, according to the present invention, the temperature signal from each temperature sensor installed in the open showcase, the temperature signal from each temperature sensor installed in the refrigerator, and the temperature signal from the pressure sensor are provided. Based on the pressure signal, the four causes of abnormalities are as follows: (1) A certain amount of frost adheres to the evaporator (2) The heat exchange performance of the condenser decreases by a certain amount or more (3) Refrigerator and showcase (4) Addition of a relatively small amount of dust and dust to the honeycomb part of the showcase to monitor the addition of a relatively small sensor, automatically detect abnormalities in the cooling system, and facilitate maintenance Thus, it is possible to provide an open showcase provided with preventive maintenance means for the cooling system.

[Brief description of the drawings]

FIG. 1 is a block diagram of an abnormality monitoring / control device for an open showcase as one embodiment of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention for monitoring abnormalities of a showcase.
Block diagram of control unit

FIG. 3 is a diagram showing another embodiment of monitoring abnormalities of a showcase.
Block diagram of control unit

FIG. 4 is a diagram showing another embodiment of the abnormality monitoring and monitoring of a showcase.
Block diagram of control unit

FIG. 5 is a configuration diagram of a main part of an open showcase.

6A and 6B are explanatory views of a main part configuration of a cooling fin of an evaporator and a state of frost formation, wherein FIG. 6A is a perspective view of the cooling fin, FIG. Frost formation diagram

FIG. 7 shows a frost formation state and an outside air temperature sensor, an inside temperature sensor,
It is a time characteristic diagram of a temperature control temperature sensor and a detection signal of a temperature and a pressure sensor on a suction side of a compressor. (A) is a time characteristic diagram of an outside air temperature sensor, an internal temperature sensor, and a temperature control temperature sensor.
(B) is a time-dependent characteristic diagram of the suction-side temperature sensor of the compressor, and (C) is a time-dependent characteristic diagram of the suction-side pressure sensor of the compressor.

FIG. 8 is a time-dependent characteristic diagram of a detection signal of an internal temperature sensor when a defrosting operation is started.

9A and 9B are explanatory diagrams of a configuration of a main part of a cooling fin of a condenser and a state of dust attachment, wherein FIG.

10A and 10B are time-dependent characteristic diagrams of a temperature and a pressure sensor on the discharge side of the compressor according to a dust attached state, FIG. 10A is a time-dependent characteristic diagram of the discharge-side temperature sensor, and FIG. Time characteristic chart

FIG. 11 is a time-dependent characteristic diagram of a detection signal of a pressure sensor on a discharge side due to clogging of a condenser and frosting / defrosting of an evaporator.

FIG. 12 is a main part configuration diagram of temperature sensors provided on an inflow side and an outflow side for cooling a cooling fin of a condenser.

FIG. 13 is a time-dependent characteristic diagram of detection signals of a temperature sensor provided on an inflow side and an outflow side of a condenser cooling fin.

FIG. 14 is a time-dependent characteristic diagram of detection signals of the pressure sensors on the suction side and the discharge side of the compressor when the refrigerant gas leaks or runs short.

FIG. 15 is a time-dependent characteristic diagram of the inside temperature and the temperature control temperature in a state where a defrosting operation is started.

FIG. 16 is a characteristic diagram of a detection signal of a pressure sensor on a discharge side when a refrigerant gas leaks or runs short.

FIG. 17 is a graph showing the temporal characteristics of the internal temperature and the regulated temperature when dust and dirt adhere to the honeycomb portion.

FIG. 18 is a graph showing the aging characteristics of the internal temperature and the temperature control temperature in a state where debris adheres to the honeycomb portion and defrosting operation is started.

FIG. 19 is a flowchart of an abnormality detection algorithm of the abnormality monitoring / control device of the open showcase as one embodiment of the present invention.

FIG. 20 is a flowchart of an abnormality detection algorithm of the abnormality monitoring / control device as another embodiment.

FIG. 21 is a flowchart of an abnormality detection algorithm of the abnormality monitoring / control device as another embodiment.

FIG. 22 is a flowchart of an abnormality detection algorithm of the abnormality monitoring / control device as another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Open showcase 10 Main body 11 Outlet 12 Display shelf 13 Opening 14 Interior 15 Duct 17 Suction port 18 Blower 2 Refrigerator 21 Evaporator 21A, 23A Refrigerant conduit 21b -21m, 23b -23m Cooling fin 21n Frost 22 Compressor 23 Condenser 23n Garbage 24 Refrigerant piping 26,26a, 26b, 26c, 26d Refrigerant 3-6 Abnormality monitoring / control device 31,41,61 Condenser / evaporator disconnecting means 32,42,62 Condenser performance deterioration detecting means 33 , 66 Honeycomb / evaporator separation means 34,67 Honeycomb clogging detection means 35,44,52,68 Evaporator frost detection means 36,65 Refrigerant gas leak detection means 43,64 Refrigerant leak / evaporator separation means 51 Evaporation / condenser separation means 63 Outside air temperature abnormality confirmation means T1 Compressor discharge side temperature sensor T2 Compressor suction side temperature sensor T3 Defrost temperature sensor T4 Temperature control temperature sensor T5 Outside air temperature sensor T6 Internal temperature sensor T7 Condenser air Inlet temperature sensor T8 Condenser air outlet temperature sensor P1 Compressor discharge pressure sensor P2 Compressor suction side pressure sensor

Continued on the front page F term (reference) 3L045 AA02 BA01 CA02 DA02 EA01 GA04 HA01 LA14 LA18 MA01 MA02 MA04 MA05 MA06 MA09 NA19 PA01 PA02 PA03 PA04 PA05 3L046 AA02 BA01 CA01 DA01 FA02 FB01 GA04 GB04 HA01 JA17 KA02 KA04 MA03 MA03 LA MA04 MA05

Claims (31)

[Claims] 1. A refrigerator which connects a compressor, a condenser and an evaporator to form a circulation system and evaporates and cools a refrigerant by the evaporator, and houses the evaporator of the refrigerator in a main body. Cooling means for circulating cool air from the evaporator from the outlet to the inlet to form an air curtain at the opening of the main body and cool the inside of the refrigerator,
In an open showcase that constitutes a cooling system that cools the interior of the refrigerator, an abnormality monitoring and control device that detects abnormalities in the cooling system and performs preventive maintenance uses the pressure on the discharge (high pressure) side of the compressor of the refrigerator. Or a sensor that measures temperature, a temperature control temperature sensor of the open showcase main body, and a temperature sensor in the refrigerator. The condenser or evaporator, etc. are determined based on the change rate of the pressure or temperature sensor signal on the discharge (high pressure) side. Condenser / evaporator separation means for separating the abnormality determination on the side of the condenser, when the condenser / evaporator separation means is on the condenser side, a condenser performance reduction detecting means for detecting a decrease in heat exchange performance of the condenser, When the evaporator disconnection means is on the evaporator / other side, the honeycomb / evaporator disconnection separates the clogging of the honeycomb of the air curtain outlet and the abnormality judgment on the evaporator / other side from the rate of change of the temperature control temperature sensor signal. Minute means and this ha Honeycomb clogging detection means for detecting honeycomb clogging when the cam / evaporator separation means is on the honeycomb side, and change rate of the temperature sensor signal in the refrigerator when the honeycomb / evaporator separation means is on the evaporator / other side An open showcase, comprising: evaporator frost detection means for detecting a frost formation abnormality of the evaporator; and refrigerant gas leakage detection means for detecting a refrigerant gas leakage abnormality from an internal temperature sensor signal. 2. A refrigerator that connects a compressor, a condenser, and an evaporator to form a circulation system and evaporates and cools a refrigerant by the evaporator, and stores the evaporator of the refrigerator in a main body. Cooling means for circulating the cool air from the evaporator from the outlet to the inlet and forming an air curtain at the opening of the main body to cool the inside of the refrigerator;
In an open showcase that constitutes a cooling system that cools the interior of the refrigerator, an abnormality monitoring and control device that detects abnormalities in the cooling system and performs preventive maintenance uses the pressure on the discharge (high pressure) side of the compressor of the refrigerator. A condenser / evaporator separating means for separating a condenser and an evaporator / other-side abnormality judgment from a change rate of a pressure or temperature sensor signal on a discharge (high pressure) side; Condenser performance reduction detecting means for detecting a decrease in heat exchange performance of the condenser when the evaporator separating means is on the condenser side, and discharge (high pressure) when the condensing / evaporator separating means is the evaporator / other side Refrigerant / evaporator disconnection means for comparing the rate of change of the pressure or temperature sensor signal on the side with the second threshold value to distinguish between refrigerant leakage and abnormality determination on the evaporator / other side; When the dividing means detects a refrigerant leak, the refrigerant leak is detected and the refrigerant is detected. And evaporator frost detecting means for detecting frost formation abnormality of the evaporator based on the rate of change in the pressure or temperature sensor signal on the discharge (high pressure) side when the evaporator separating means is on the evaporator side. Open showcase characterized by: 3. A refrigerator that connects a compressor, a condenser, and an evaporator to form a circulation system and evaporates and cools a refrigerant by the evaporator, and houses the evaporator of the refrigerator in a main body. Cooling means for circulating the cool air from the evaporator from the outlet to the inlet and forming an air curtain at the opening of the main body to cool the inside of the refrigerator;
In an open showcase that constitutes a cooling system that cools the interior of the refrigerator, an abnormality monitoring and control device that detects abnormalities in the cooling system and performs preventive maintenance uses the temperature on the discharge (high pressure) side of the compressor of the refrigerator. , A temperature sensor for measuring the suction (low pressure) side temperature, a temperature control temperature sensor of the open showcase main body, and a temperature sensor in the refrigerator, and a temperature sensor signal for the suction (low pressure) side Evaporator / condenser separating means for distinguishing the abnormality determination of the evaporator and the condenser / other side from the rate of change of the temperature, and a temperature sensor on the suction (low pressure) side when the evaporator / condenser separating means is on the evaporator side Signal change rate and discharge (high pressure)
Frost detection means for detecting the frost formation abnormality of the evaporator from the rate of change of the temperature sensor signal on the side, and the temperature sensor on the discharge (high pressure) side when the evaporator / condenser separation means is the condenser / other side An open showcase comprising: condensation / refrigerant leakage separation means for determining whether the heat exchange performance of the condenser is degraded or the refrigerant gas is abnormal based on the rate of change of the signal. 4. A refrigerator that connects a compressor, a condenser and an evaporator to form a circulation system and evaporates and cools a refrigerant by the evaporator, and houses the evaporator of the refrigerator in a main body. Cooling means for circulating the cool air from the evaporation 4 from the outlet to the inlet and forming an air curtain at the opening of the main body to cool the inside of the refrigerator;
In an open showcase that constitutes a cooling system that cools the interior of the refrigerator, the abnormality monitoring and control device that detects abnormalities in the cooling system and performs preventive maintenance uses basic data at the time of installing the refrigerator and data after the next day of installation. And a pressure sensor for measuring the pressure on the discharge (high pressure) side of the compressor of the refrigerator, a temperature control temperature sensor on the open showcase body, and a temperature sensor in the refrigerator. Condenser / evaporator separation means for distinguishing abnormality determination between the condenser and the evaporator / other side from the rate of change of the pressure sensor signal, and heat exchange of the condenser when the condensation / evaporator separation means is on the condenser side When the condenser performance degradation detecting means for detecting the performance degradation and the condenser / evaporator separation means are on the evaporator / other side, the time data required for the regulated temperature after defrosting to drop to a predetermined temperature is obtained. One day's worth of time data Refrigerant leakage / evaporator separation means for comparing refrigerant gas leakage and abnormality determination on the evaporator / other side by comparing the deviation ΔT with basic data corrected by a predetermined coefficient; A refrigerant gas leak detecting means for detecting a refrigerant gas leak when the dividing means continuously detects a refrigerant gas leak side a predetermined number of times; and a refrigerant gas / evaporator separating means for evaporator / other side.
The time data required for the internal temperature after the defrost to drop to the predetermined temperature is collected for one day, and the maximum deviation ΔT ′ of this time data is compared with the basic data corrected by the predetermined coefficient. Honeycomb / evaporator separation means for separating abnormality determination between the honeycomb and the evaporator side, honeycomb clogging detection means for detecting honeycomb clogging when the honeycomb side continues for a specified number of times, and a change rate of the temperature in the refrigerator and a predetermined value. An evaporator frost detecting means for detecting frost formation abnormality by comparing the basic data corrected by the coefficient with the obtained coefficient. 5. The open showcase according to claim 1, further comprising an outside air temperature sensor, wherein when the honeycomb / evaporator separation means is on the other side of the evaporator, the change rate of the internal temperature sensor signal is detected by the outside air temperature sensor. An open showcase, wherein the rate of change of the internal temperature sensor signal is corrected from the value of the rate of change of the signal to detect abnormal frost formation on the evaporator. 6. The open showcase according to claim 1, wherein the condenser / evaporator separating means calculates a change rate of the pressure or temperature sensor signal on the discharge (high pressure) side per unit time. Means for comparing the rate of change with a predetermined threshold value A, and selecting the condenser side when the rate of change is equal to or greater than the threshold value A, and evaporating when the rate of change is less than the threshold value A. An open showcase characterized by selecting a vessel and the other side. 7. The open showcase according to claim 1, wherein the condenser performance deterioration detecting means compares a pressure or temperature sensor signal on the discharge (high pressure) side with a predetermined threshold value G. Comparing means for comparing a signal change rate per unit time of a pressure or temperature sensor signal on the discharge (high pressure) side with a predetermined threshold value H, wherein both comparing means are equal to or greater than the threshold values G and H An open showcase characterized by detecting a decrease in the heat exchange performance of the condenser when: 8. The open showcase according to claim 1, wherein the honeycomb / evaporator separating means is configured to control a signal change per unit time of the temperature control temperature sensor signal. A change rate calculating means for calculating the change rate; and a comparing means for comparing the change rate with a predetermined threshold value C. When the change rate is smaller than the threshold value C, the honeycomb clogging side is selected. An open showcase, wherein the evaporator / other side is selected when the rate is equal to or higher than the threshold value C. 9. The open showcase according to claim 1, wherein the honeycomb clogging detecting means compares the internal temperature sensor signal with a predetermined threshold value E. And a comparing means for comparing, wherein when the temperature in the refrigerator is equal to or higher than the threshold value E, the honeycomb clogging of the outlet of the air curtain is detected. 10. The method of claim 1 or claim 6 to claim 9.
In the open showcase according to any one of the above items, the evaporator frost detection means comprises a comparison means for comparing the rate of change of the in-chamber temperature sensor signal with a predetermined threshold D, the rate of change An open showcase characterized by detecting a frost formation abnormality of the evaporator when is greater than or equal to a threshold value D. 11. The method of claim 1 or claim 6 to claim 1.
0, the evaporator frost detection means comprises: a change rate calculating means for calculating a signal change rate per unit time of the outside air temperature sensor signal; and an internal temperature based on the change rate. A correction calculating means for correcting the rate of change of the sensor signal; and a comparing means for comparing the correction value with a predetermined threshold value D. When the correction value is equal to or greater than the threshold value D, the frost formation abnormality of the evaporator is determined. An open showcase characterized by detecting. 12. The open showcase according to claim 11, wherein the evaporator frost detection means comprises a correction database for correcting the rate of change of the inside temperature sensor signal based on the rate of change of the outside air temperature sensor signal. An open showcase characterized by the following. 13. The method of claim 1 or claim 6 to claim 1.
2. The open gas showcase according to any one of the items 2, wherein the refrigerant gas leakage detecting means includes: comparing means for comparing the inside temperature sensor signal with a predetermined threshold value F; An open showcase that detects a refrigerant gas leak in the above case. 14. The open showcase according to claim 2, wherein a signal of a pressure or temperature sensor on the discharge (high pressure) side after defrosting is input on a daily basis, and the condensing / evaporator separating means receives the signal. Change rate calculating means for calculating a signal change rate per unit time (long term) of the pressure or temperature sensor signal on the discharge (high pressure) side, comparing means for comparing the change rate with a predetermined threshold value H, An open showcase comprising: selecting the condenser side when the rate of change is equal to or higher than the threshold value H, and selecting the evaporator / other side when the rate of change is smaller than the threshold value H. 15. The open showcase according to claim 2, wherein the condenser performance deterioration detecting means compares a pressure or temperature sensor signal on the discharge (high pressure) side with a predetermined threshold value G. An open showcase, comprising: comparing means, wherein when the comparing means is equal to or larger than the threshold value G, a decrease in heat exchange performance of the condenser is detected. 16. The method according to claim 2, 14 or 15.
In the open showcase according to any one of the above items, the refrigerant gas leak detecting means compares the rate of change (long term) of the pressure or temperature sensor signal on the discharge (high pressure) side with a predetermined threshold value J. Means for detecting refrigerant gas leakage when the rate of change (long term) is smaller than a threshold value J. 17. The open showcase according to claim 2, wherein the evaporator frost detection means discharges (high pressure) at an interval between defrosting and defrosting. Comparing means for receiving a signal of the pressure or temperature sensor on the discharge side and comparing a rate of change (short term) per unit time of the pressure or temperature sensor signal on the discharge (high pressure) side with a predetermined threshold K. An open showcase, comprising: detecting a frost formation abnormality of the evaporator when the rate of change is smaller than a threshold value K. 18. The open showcase according to claim 3, wherein a signal of the temperature sensor on the discharge (high pressure) side and a signal of the temperature sensor on the suction (low pressure) side after defrosting are input on a daily basis. / Evaporator separating means for calculating a change rate (long term) of a signal change per unit time (long term) of the temperature sensor signal on the suction (low pressure) side, and the change rate and a predetermined threshold value A Comparing means for comparing the evaporator when the rate of change is greater than or equal to the threshold value A, and selecting the condenser / other side when the rate of change is less than the threshold value A. Showcase. 19. The open showcase according to claim 3, wherein the evaporator frost detection means includes a temperature sensor signal on a discharge (high pressure) side and a suction (low pressure) at an interval between defrosting and defrosting. ) -Side temperature sensor signal, a change rate calculating means for calculating a signal change rate per unit time (short period) of the suction (low pressure) side temperature sensor signal, and a discharge rate (high pressure) side temperature sensor signal. A change rate calculating means for calculating a signal change rate (short term) per unit time; and a comparing means for comparing both change rates with a predetermined threshold K, wherein both change rates are smaller than the threshold K. An open showcase characterized by detecting abnormal frost formation on the evaporator at the time. 20. The method of claim 3, 18 or 19.
In the open showcase according to any one of the above items, the condensing / refrigerant leakage separation means calculates a signal change rate (long term) of the temperature sensor signal on the discharge (high pressure) side per unit time (long term). And a comparing means for comparing the rate of change with a predetermined threshold A. When the rate of change is greater than the threshold A, a decrease in the heat exchange performance of the condenser is detected, and the rate of change is smaller than the threshold A. An open showcase that detects a refrigerant gas leak when: 21. The open showcase according to claim 4, wherein the condensing / evaporator separating means includes a change rate calculating means for calculating a signal change rate per unit time of the discharge (high pressure) side pressure sensor signal. A change rate calculating means for calculating a signal change rate per unit time of the internal temperature signal; and a signal change rate basic data of a discharge (high pressure) side pressure sensor signal among basic data collected when the refrigerator is installed. A correction operation means for a threshold value A (A5) corrected by a predetermined coefficient, and when the rate of change is equal to or greater than the corrected threshold value A (A5), the condensation side is selected. Case. 22. The open show case according to claim 4, wherein the condenser performance deterioration detecting means compares a pressure sensor signal on the discharge (high pressure) side with a predetermined threshold value G. And a comparing means for comparing the rate of change of the pressure sensor signal on the discharge (high pressure) side with a predetermined threshold H. When both rates of change are equal to or greater than the threshold G and the threshold H, respectively, heat exchange of the condenser is performed. An open showcase characterized by detecting performance degradation. 23. The method according to claim 4, 21 or 22.
In the open showcase according to any one of the above items, the refrigerant leakage / evaporator separation means collects one day's worth of time data required for the temperature control temperature after defrosting to drop to a predetermined temperature, Maximum deviation ΔT calculating means for measuring and calculating the difference between the maximum value and the minimum value of the time data and the maximum deviation ΔT;
A correction operation means for correcting basic data collected at the time of installing the refrigerator by a predetermined coefficient; and a comparison means for comparing both values of the maximum deviation ΔT operation means and the correction operation means, and measuring the maximum deviation ΔT An open showcase wherein the refrigerant gas leak side is selected when the data is equal to or greater than the basic data value corrected by a predetermined coefficient. 24. Claims 4, 21 to 23
In the open showcase according to any one of the above items, the refrigerant gas leakage detection means, when the refrigerant leakage / evaporator separation means has selected the refrigerant gas leakage side continuously for a predetermined predetermined number of times, An open showcase characterized by detecting abnormalities. 25. Claims 4, 21 to 24
In the open showcase according to any one of the above items, the honeycomb / evaporator separation means collects one day's worth of time data required for the internal temperature after defrost to drop to a predetermined temperature, and A maximum deviation ΔT ′ calculating means for measuring and calculating the difference between the maximum value and the minimum value of the time data and the maximum deviation ΔT ′,
A correction calculating means for correcting the basic data collected at the time of installing the refrigerator with a predetermined coefficient; and a comparing means for comparing both values of the maximum deviation ΔT calculating means and the correction calculating means. An open showcase, wherein the honeycomb side is selected when the deviation ΔT ′ is equal to or greater than a basic data value corrected by a predetermined coefficient. 26. Claims 4, 21 to 25
In the open showcase according to any one of the above items, the honeycomb clogging detection means detects the honeycomb clogging when the honeycomb / evaporator separation means continuously selects the honeycomb side for a predetermined specified number of times. An open showcase characterized by that. 27. Claims 21, 21 and 26.
In the open showcase according to any one of the above, the evaporator frost detection means, the change rate calculating means for calculating the signal change rate per unit time of the internal temperature signal, and basic data collected at the time of installing the refrigerator , The threshold value A in which the basic data of the signal change rate of the internal temperature signal is corrected by a predetermined coefficient.
(A5) correction calculating means, wherein when the rate of change of the internal temperature is larger than a basic data value corrected by a predetermined coefficient, an abnormal frost formation of the evaporator is detected. Open showcase. 28. The open showcase according to any one of claims 1 to 4, or 7, 15, 20, and 22, wherein the means for detecting deterioration of the condenser performance is provided before and after the cooling fins of the condenser. An open showcase, which is equipped with a temperature sensor and detects a clogging abnormality of the condenser based on the temperature difference between the two sensors. 29. Claims 1 to 4 or 1
In the open showcase according to any one of Items 6 and 24, the refrigerant gas leak detection means includes a temperature sensor at a pipe portion at an entrance and exit of the evaporator, and detects a refrigerant gas leakage abnormality from a temperature difference between the two sensors. An open showcase characterized by that. 30. Claim 1 to Claim 4 or Claim 1
In the open showcase according to any one of Items 6 and 24, the refrigerant gas leak detection means includes a pressure or temperature sensor on the discharge (high pressure) side or a pressure or temperature sensor on the suction (low pressure) side. An open showcase characterized by detecting a refrigerant gas leakage abnormality from a variation width of a detection signal detected by the sensor. 31. The open showcase according to any one of claims 1 to 30, wherein the measurement data is collected at night when there is little change in the surrounding environment. .