JP4396301B2 - Refrigeration unit and refrigerator using the same - Google Patents

Description

  The present invention relates to a refrigeration unit and a refrigerator using the same.

  Most of recent refrigerators are electronically controlled using a microcomputer, so that the temperature of the inside of the refrigerator is generally used by a thermistor for temperature detection, which is mainly used in restaurants and the like. There is no exception in the commercial refrigerator. When this temperature detection thermistor fails, the compressor is continuously stopped, the internal temperature rises, or a supercooled state due to continuous operation occurs. Therefore, in commercial refrigerators, control for avoiding loss due to spoilage or freezing of a large amount of stored food is a very important technology.

  As a conventional refrigerator, when the temperature detector in the refrigerator breaks down, the compressor temperature and the motor damper are controlled by the on-off control according to the preset time pattern from the control by the internal temperature. There is one that prevents the food from being frozen due to overcooling or the food from being spoiled due to a rise in the internal temperature, and displays a failure (for example, see Patent Document 1).

  Hereinafter, the conventional refrigerator will be described with reference to the drawings.

  FIG. 6 is a control block diagram of a conventional refrigerator. As shown in FIG. 6, the conventional refrigerator is driven by the compressor 101, the internal temperature detection means 102, the A / D conversion unit 103, the comparison circuit unit 104, the control unit 105, and the set temperature storage unit 106. The unit 107 includes a time pattern data storage unit 108 and a failure display unit 109.

  About the refrigerator comprised as mentioned above, the operation | movement is demonstrated below.

  The internal temperature detection means 102 comprises a temperature detection sensor (thermistor) R1 and a voltage dividing resistor R2 as shown in FIG. 7A, and the output voltage from the output terminal A is A / D. After A / D conversion by the conversion unit 103, it is input to the comparison circuit unit 104 and the control unit 105. The detection data input to the comparison circuit unit 104 is compared with the set value of the internal temperature stored in the storage unit 106, and the comparison result is input to the control unit 105. Then, based on the comparison result, for example, when the internal temperature is higher than the set temperature stored in the storage unit 106, the control unit 105 controls the drive unit 107 to operate the compressor 101. On the other hand, when the internal temperature is lower than the set temperature, the operation of the compressor 101 is stopped and the internal temperature is controlled to approach the set temperature.

  Reference numeral 108 denotes a time pattern data storage unit. The time pattern data stored in the storage unit 108 is, for example, an operation time T1 of the compressor 101 that is repeated when the electric refrigerator is in a normal state and the ambient temperature is 25 ° C. And the stop time T2 are patterned. This time pattern data is not called into the control unit as long as the internal temperature detection means 102 maintains a normal function, and the temperature detection sensor (thermistor) R1 of the internal temperature detection means 102 is disconnected. Or the data is used for the first time when the compressor 101 remains in an ON state due to a short circuit or conversely remains in an OFF state.

  FIG. 7B shows the output voltage characteristics of the internal temperature detection means 102. In the figure, the operating temperature range is a temperature detection sensor (thermistor) R1 that can be considered when the electric refrigerator is powered on. In the case of the one for the freezer compartment 1, for example, it is in the range of about −40 ° C. to + 50 ° C. When the conversion range of the A / D conversion unit 103 is 0 to 5 V, the resistance value of the voltage dividing resistor R2 is selected so that the result of the A / D conversion does not become the minimum value or the maximum value in this operating temperature range. .

  By the way, in the internal temperature detection means 102, if the temperature detection sensor (thermistor) R1 is disconnected, the output voltage becomes the minimum value (0 V), so the operation of the compressor 12 is stopped, and the temperature detection sensor (thermistor) ) If R1 is short-circuited, the output voltage value becomes the maximum value (5 V), so the compressor 12 is in a continuous operation state.

However, a program for determining such an abnormal value of the output voltage is set in the control unit 105, and when these abnormal values are found, the compressor 101 and the like are controlled by using the output change of the internal temperature detecting means 102. The original control to be controlled is stopped, and instead, the compressor 101 is controlled to be turned on and off based on the time pattern data stored in the storage unit 108, and the failure display unit 21 displays a failure display. Yes. In this way, if the emergency operation is performed based on the time pattern data when the internal temperature detecting means 102 fails, the food stored in the internal compartment can be prevented from being spoiled or frozen.
Japanese Utility Model Publication No. 5-10978

  However, in the above configuration, when an abnormality occurs in the temperature detection means in the refrigerator, the compressor is turned on and off according to a preset time pattern, but the blower for circulating cold air in the refrigerator cannot be driven. Therefore, the internal temperature is insufficient to suppress the rise. Furthermore, since it is ON / OFF control of the compressor, it can be applied to a constant speed compressor equipped with an induction motor, but it is unclear how many revolutions the inverter compressor can drive with an inverter compressor that can change the rotational speed of the compressor. For this reason, there was a drawback that it was impossible to put to practical use.

  Further, when the compressor is turned on / off at a constant speed and at a constant time interval, if the condenser temperature rises abnormally, the compressor temperature also rises, and there is a risk that the compressor will fail. Furthermore, in the above configuration, since the compressor is always driven and stopped at a constant cycle regardless of the ambient outside temperature in which the refrigerator is installed, in the low outside temperature environment, the interior is overcooled and the high outside temperature is increased. In the environment, there was a possibility of a slow cooling.

  Furthermore, for commercial refrigerators mainly used in restaurants, etc., the set temperature range of the refrigerator compartment is particularly wide (for example, -5 ° C to + 15 ° C). With the above configuration, the compressor is driven at a constant cycle regardless of the set temperature. In addition, since the operation is stopped, it is difficult to realize the internal temperature close to the set temperature intended by the user.

  The present invention solves the conventional problem, and in the event that the internal temperature detector breaks down, the compressor and the evaporator are vaporized in a preset state depending on the outside temperature of the refrigerator installation environment and the set temperature in the refrigerator. Because the refrigerator fan and the condenser fan are driven, even if the internal temperature detector fails, the temperature inside the refrigerator is close to the set temperature, as well as preventing the food from rotting or freezing due to an increase in the refrigerator internal temperature and overcooling. Since the temperature can be realized, even if the internal temperature detector fails, the freshness of the stored food is improved, and when the condensation temperature is high, the compressor can be prevented from malfunctioning because the maximum rotation speed of the compressor is limited. An object of the present invention is to provide a refrigeration unit and a refrigerator using the same.

  Furthermore, the above-mentioned conventional configuration detects the outside air temperature when controlling the ON / OFF of the sweat prevention heater provided to prevent sweating of the refrigerator wall due to the difference between the outside temperature where the refrigerator is installed and the inside temperature of the refrigerator. When the appliance breaks down, the heater is always turned off, and the refrigerator wall sweats.

  Another object of the present invention is to prevent sweating of the outer wall of the refrigerator even when the outside temperature detector that detects the outside temperature of the refrigerator installation environment breaks down.

  Furthermore, in the above conventional configuration, when the internal temperature detecting means fails, the failure is displayed and a warning is given to the user. However, when the other temperature detector fails, the failure display cannot be performed. When the defrosting end detector or the outside air temperature detector breaks down, there is a drawback that it is difficult for the user to notice.

  Another object of the present invention is that when any temperature detector fails, it is possible to identify the failed temperature detector and inform the user, so that a quick repair request is possible. You can tell which temperature detector has failed, shorten the repair time, enable smooth response, and improve maintainability.

In order to solve the above-described problems, the present invention provides an internal temperature detector that detects the internal temperature of a refrigerator, a condensing temperature detector that is attached to the condenser of the refrigeration cycle and detects the condensing temperature of the refrigerant, and an evaporator or A freezing / refrigeration unit having a defrosting end detector that is installed near the evaporator and detects the end of the defrosting, and an outside air temperature detector that detects the ambient temperature of the refrigerator, and the temperature detected by each of the temperature detectors. Based on the operating state determining means for determining the operating state of the compressor, the evaporator fan, the condenser fan, the defrosting heater, the anti-perspiration heater, etc., and the internal temperature detector abnormality detecting the abnormality of the internal temperature detector A detection means, a condensation temperature detector abnormality detection means for detecting an abnormality of the condensation temperature detector, a defrost end detector abnormality detection means for detecting an abnormality of the defrost end detector, and an outside air temperature detector. Detect anomalies An outside temperature detector abnormality detecting means, and when at least one of the temperature detectors detects an abnormality, an emergency driving means for performing an emergency operation is provided, and the operating state determining means and the emergency driving means, Control switching means for switching between, and when the abnormality of the outside air temperature detector is detected by the outside air temperature detector abnormality detecting means, the emergency switching means is selected by the control switching means, and the energization rate of the sweating prevention heater is set. It is intended to maximize duty ratio, even when an abnormality occurs in the temperature detector, by performing an emergency operation, freezing and food by supercooling in the refrigerator compartment, losses due to spoilage of food due to the internal temperature rise Can be prevented and sweating of the outer wall of the refrigerator can be prevented.

According to the present invention, the internal temperature detector that detects the internal temperature of the refrigerator, the condensing temperature detector that is attached to the condenser of the refrigeration cycle and detects the condensing temperature of the refrigerant, and installed in the vicinity of the evaporator or the evaporator A freezing and refrigeration unit comprising a defrosting end detector for detecting the end of defrosting and an outside air temperature detector for detecting the installation ambient temperature of the refrigerator, based on the temperature detected by each of the temperature detectors, An operating state determining means for determining an operating state of an evaporator fan, a condenser fan, a defrosting heater, an antiperspirant heater, and the like; an internal temperature detector abnormality detecting means for detecting an abnormality of the internal temperature detector; Condensation temperature detector abnormality detecting means for detecting abnormality of the condensation temperature detector, defrosting end detector abnormality detecting means for detecting abnormality of the defrosting end detector, and outside air detecting abnormality of the outside air temperature detector Temperature detector And a control switching means for switching between the operating state determining means and the emergency driving means, and having an emergency driving means for performing an emergency driving when at least one of the temperature detectors detects an abnormality. When the abnormality of the outside temperature detector is detected by the outside temperature detector abnormality detecting means, the emergency switching means is selected by the control switching means, and the conduction rate of the antiperspirant heater is set to the maximum conduction rate. is intended, even if the abnormality in the temperature detector has occurred, by performing an emergency operation, freezing and food by supercooling in the refrigerator cabinet, it is possible to prevent losses due to spoilage of food due to the internal temperature rise It is possible to prevent sweating on the outer wall of the refrigerator.

The invention according to claim 1 is an internal temperature detector for detecting the internal temperature of the refrigerator, a condensing temperature detector that is attached to the condenser of the refrigeration cycle and detects the condensing temperature of the refrigerant, and an evaporator or an evaporator A freezing and refrigeration unit having a defrosting end detector that is installed in the vicinity and detects the end of defrosting, and an outside air temperature detector that detects an installation atmosphere temperature of the refrigerator, based on the temperature detected by each temperature detector Operating state determining means for determining operating states of a compressor, an evaporator fan, a condenser fan, a defrosting heater, an antiperspiration heater, etc., and an internal temperature detector abnormality detecting means for detecting an abnormality of the internal temperature detector A condensation temperature detector abnormality detecting means for detecting an abnormality of the condensation temperature detector, a defrosting completion detector abnormality detecting means for detecting an abnormality of the defrosting completion detector, and an abnormality of the outside air temperature detector. Detecting outside temperature A detector anomaly detection means, and an emergency operation means for performing an emergency operation when at least one of the temperature detectors detects an abnormality, and a control for switching between the operation state determination means and the emergency operation means A switching means, and when the outside air temperature detector abnormality is detected by the outside air temperature detector abnormality detecting means, the emergency switching means is selected by the control switching means, and the conduction rate of the sweating prevention heater is set to the maximum conduction rate. is intended to be, even if an abnormality occurs in the temperature detector, by performing an emergency operation, to prevent freezing and food by supercooling in the refrigerator compartment, the losses due to spoilage of food due to the internal temperature rise It is possible to prevent sweating on the outer wall of the refrigerator.

The invention according to claim 2 is an internal temperature detector that detects the internal temperature of the refrigerator, a condensing temperature detector that is attached to the condenser of the refrigeration cycle and detects the condensing temperature of the refrigerant, and an evaporator or an evaporator A freezing and refrigeration unit having a defrosting end detector that is installed in the vicinity and detects the end of defrosting, and an outside air temperature detector that detects an installation atmosphere temperature of the refrigerator, based on the temperature detected by each temperature detector Operating state determining means for determining operating states of a compressor, an evaporator fan, a condenser fan, a defrosting heater, an antiperspiration heater, etc., and an internal temperature detector abnormality detecting means for detecting an abnormality of the internal temperature detector A condensation temperature detector abnormality detecting means for detecting an abnormality of the condensation temperature detector, a defrosting completion detector abnormality detecting means for detecting an abnormality of the defrosting completion detector, and an abnormality of the outside air temperature detector. Detecting outside temperature A detector anomaly detection means, and an emergency operation means for performing an emergency operation when at least one of the temperature detectors detects an abnormality, and a control for switching between the operation state determination means and the emergency operation means A switching means, and when an abnormality of the outside air temperature detector is detected by the outside air temperature detector abnormality detecting means, an emergency operation means is selected by the control switching means and detected by the condensing temperature detector immediately after completion of defrosting. The heat conduction rate of the anti-sweat heater is determined based on the temperature, and even if an abnormality occurs in each temperature detector, the emergency operation is performed to freeze the food by overcooling in the refrigerator cabinet. In addition, it is possible to prevent food loss due to food temperature rise due to the rise in the internal temperature, and it is possible to detect a temperature close to the actual outside air temperature with the condensation temperature detector. Prevention of sweating walls, of course, since the operation of the antiperspirant heater for the outside air temperature, can be controlled by operating close to the optimal duty ratio, it is possible to suppress an increase in power consumption.

Invention according to claim 3, in the invention described in claim 1 or 2, comprising display means for displaying the refrigerator operating conditions, if it detects an abnormality of the temperature detector is abnormal state temperature When the refrigerator is in an emergency operation state, a warning is displayed to indicate that it is in an emergency operation by identifying the detector and displaying an abnormality, so the user of the refrigerator is in an emergency operation state because the refrigerator is in an abnormal state. Since it can be recognized, it is possible to promptly respond to repair requests. In addition, it is possible to identify the temperature detector in an abnormal state, so it is possible to tell which temperature detector has failed when requesting repairs, and the repairer can immediately identify which temperature detector has failed. Since it can be recognized, the repair time can be shortened and a smooth response can be achieved.

Invention of Claim 4 arrange | positions the refrigeration unit as described in any one of Claim 1 to 3 removably on the refrigerator main body upper part or side part, and uses a combustible refrigerant | coolant as a refrigerant | coolant. It is possible to carry out repair work by removing the refrigeration unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, about the same structure as the past, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a block diagram of a refrigeration unit and a refrigerator using the same according to Embodiment 1 of the present invention, and FIG. 2 is a configuration diagram of a cooling cycle of the refrigerator according to Embodiment 1 of the present invention. FIG. 3 is a schematic configuration diagram of the refrigerator according to the first embodiment of the present invention.

  As shown in FIG. 2, the cooling cycle of the refrigerator of the present invention includes an inverter compressor 1 that can change a driving speed using a brushless DC motor that compresses a gaseous refrigerant, and a gaseous combustible refrigerant (for example, R600a or The condenser 2 for condensing R290), the capillary 3 for reducing the pressure of the liquid refrigerant, and the evaporator 5 for cooling the storage chamber 4 for storing the food in the refrigerator by evaporating the liquid refrigerant. The condenser fan cools the condenser 2 and thereby cools the high-temperature gas refrigerant sent by the compressor 1, thereby promoting the condensation of the refrigerant.

  The evaporator fan 7 is installed in the vicinity of the evaporator in the refrigerator cabinet so as to circulate the cold air cooled by the evaporator 5 in the cabinet. Here, the condenser fan 6 and the evaporator fan 7 employ DC motors whose rotation speeds can be varied by driving voltages. The defrost heater 8 is installed in the vicinity of the evaporator 5 to remove frost attached to the evaporator 5.

  FIG. 3 shows the refrigerator according to the first embodiment. Inside the refrigerator, the storage chambers 4a, 4b, 4c, and 4c divided into four are cooled by two sets having a compressor, a condenser, a capillary tube, and an evaporator. It is cooled by the unit. The sweating prevention heater 10 is embedded in front surfaces of the outer walls 11a to 11d that contact the refrigerator door and the threshold walls 12a to 12d of the storage chambers 4a to 4d, and prevents sweating due to a temperature difference between the internal temperature and the outside air temperature. Is provided.

  In FIG. 1, the internal temperature detector 13 for detecting the internal temperature of the refrigerator and the condensing temperature detector 14 for detecting the condensing temperature of the refrigerant attached to the condenser 2, the evaporator 5 or the vicinity of the evaporator 5 are installed. The defrosting end detector 15 for detecting the end of the defrosting and the outside temperature detector 16 for detecting the outside temperature of the environment where the refrigerator is installed are composed of a temperature detecting thermistor, and the resistance when the ambient temperature of the thermistor is low. As shown in FIG. 4, the partial pressure of the resistance connected in series with the thermistor is condensed into the internal temperature detection means 17 using the negative characteristic that the resistance value increases when the value is large and the ambient temperature is high. By inputting the temperature detection means 18, the defrosting end detection means 19, and the outside air temperature detection means 20, the respective temperatures are detected.

  The inside temperature detector abnormality detecting means 21, the condensation temperature detector abnormality detecting means 22, the defrosting end detector abnormality detecting means 23 and the outside air temperature detector abnormality detecting means 24 are the same as the inside temperature detecting means 17, the condensation temperature detecting means. From the outputs of the means 18, the defrosting end detecting means 19, and the outside air temperature detecting means 20, the inside temperature detector 13, the condensation temperature detector 14, the defrosting end detector 15, and the outside air temperature detector 16 are in an abnormal state. Is to detect.

  The control method switching means 25 outputs the output signals from the inside temperature detector abnormality detecting means 21, the condensation temperature detector abnormality detecting means 22, the defrosting end detector abnormality detecting means 23, and the outside air temperature detector abnormality detecting means 24. If all the temperature detectors are normal, the operating state determining means 26 determines the driving states of the compressor 1, the condenser fan 6, the evaporator fan 7, the defrosting heater 8, and the antiperspirant heater 10. The compressor drive means 28, the condenser fan drive means 29, the evaporator fan drive means 30, the defrost heater drive means 31, and the antiperspiration heater drive means 32 are instructed to run / stop, and each load is driven or stopped.

  When the display unit 33 is driven by the operation state determination unit 26, the current internal temperature of the storage chambers 4a to 4d or the set temperature of each storage chamber, and the temperature of the condensation temperature detector 14 rises to a specified temperature. When the emergency operation means 27 is used to drive the filter, a filter that is in an abnormal state is identified and displayed abnormally. Is.

  The operation of the refrigeration unit configured as described above and a refrigerator using the same will be described below.

  As shown in FIG. 4, the internal temperature detector 13, the condensation temperature detector 14, the defrosting end detector 15, and the outside air temperature detector 16 are connected in series with the resistors. A divided voltage is output. The internal temperature detection means 17, the condensation temperature detection means 18, the defrosting end detection means 19, and the outside air temperature detection means 20 receive this voltage and detect each temperature by A / D conversion to detect the internal temperature. Output to the detector abnormality detecting means 21, the condensation temperature detector abnormality detecting means 22, the defrosting end detector abnormality detecting means 23, and the outside air temperature detector abnormality detecting means 24.

  Here, when each temperature detector has a short circuit failure, a voltage of 5 V is input, and when an open failure occurs, a voltage of 0 V is input. Therefore, when a short circuit or an open failure occurs in each detector, a temperature that cannot be actually used in the refrigerator (for example, −100 ° C. or + 100 ° C. at the internal temperature) is detected. Next, each failure detection means, when the temperature detected by all the detectors is within a preset temperature range (for example, -40 ° C to + 40 ° C for the internal temperature,- 20 ° C to + 80 ° C, -40 ° C to + 40 ° C for the defrosting end temperature, -20 ° C to + 50 ° C for the outside air temperature detector) The control method switching means 25 selects the operating state determining means 26 and the driving state of each load. To decide.

  Moreover, in the operation state determination means, the present refrigerator state is displayed by the display means 33 by displaying the current internal temperature state or set temperature state of the storage rooms 4a to 4d, so that the user can check the current refrigerator state.

  Now, determination of the driving state by the driving state determination means will be described. First, the drive state of the compressor 1 is determined by determining the operation rotational speed of the compressor 1 based on the internal set temperature preset in the operation state determining means and the internal temperature detected by the internal temperature detector ( For example, when the initial rotational speed at startup of the compressor is 40 r / s and the internal temperature is higher than the set temperature by 1 ° C. or more, the compressor rotational speed is increased by 10 r / s every 5 minutes. When the temperature is higher than 0 ° C and lower than 1 ° C, the compressor speed is decreased by 10 r / s every 5 minutes.If the internal temperature becomes lower than the set temperature, the internal temperature becomes lower than the set temperature. If it is large and high, the compressor speed can be increased to increase the cooling rate when the internal temperature rises. When the internal temperature is close to the set temperature, the compressor is driven at low speed to save energy. Can do.

  FIG. 5 shows the relationship between the evaporation (inside chamber) temperature and the condensation temperature in the compressor usage range, and the shaded area is the compressor usage range. As shown in FIG. 5, when the evaporation (inside) temperature is high (Tj or more), the condensation temperature is allowed up to Tg, and when the evaporation (inside) temperature is low (less than Tg), the condensation temperature is Tg. It needs to be kept lower.

  Therefore, when the compressor is driven, the compressor speed is decreased when the condensing temperature with respect to the internal temperature approaches or reaches the upper limit temperature of the operating range of the compressor while monitoring the internal temperature and the condensing temperature. The compressor is prevented from malfunctioning by suppressing the rise in the condensation temperature. The compressor is driven or stopped by the compressor driving means 28 according to the determined command rotational speed of the compressor.

  The determination of the driving state of the condensing fan 6 is driven or stopped in synchronization with the driving or stopping of the compressor 1. During driving of the compressor, the voltage to be driven is determined by the temperature detected by the condensing temperature detector (for example, the driving voltage when the condensing temperature is less than 30 ° C. is 8 V, and the condensing temperature is 10 ° C. when the condensing temperature is less than 40 ° C. When the condensation temperature exceeds 40 ° C., the compressor voltage 1 is increased by increasing the drive voltage and driving the condenser fan at a higher rotational speed as the condensation temperature is higher. To prevent malfunction. Further, since a flammable refrigerant is used, even if the refrigerant leaks, it can diffuse without staying.

  The operation state of the evaporator fan is determined by the operation speed of the compressor 1 (for example, when the compressor drive speed is 0 r / s to less than 30 r / s, it is 8 V drive, 30 r / s to less than 50 r / s By driving at 10V and 12V at 50r / s or higher, the cooling time in the refrigerator can be shortened by operating the fan at high speed while the refrigerator temperature is high and the compressor is rotating at high speed. Then, energy saving drive is possible by low speed drive.

  The determination of the operating state of the defrosting heater is started when the elapsed time from the end of the previous defrosting is a time set in advance in the operating state determination means 26. Further, the defrosting is completed when the temperature detected by the defrosting completion detector reaches a temperature (for example, 15 ° C.) preset in the operation state determining means 26, and the evaporator 5 is By removing the attached frost, a decrease in cooling performance due to frost formation on the evaporator is prevented.

  During the defrosting, the operation state determination means 26 outputs a stop command for the compressor 1, the condenser fan 6, and the evaporator fan to each driving means to stop it.

  The operation state of the sweating prevention heater is determined by the difference between the outside air temperature detected by the outside air temperature detector 16 and the set temperature of the interiors 4a to 4d set in the operation state determining means 26 (for example, temperature When the difference is 20 ° C. or less, the conduction rate is 40%, the conduction rate is 60% for 20 ° C. or more and less than 40 ° C., and the conduction rate is 80% for 40 ° C. or more. To save energy.

  Next, the temperatures inputted to the internal temperature detector abnormality detection means 17, the condenser temperature detector abnormality detection means 18, the defrosting end detector detection means 19 and the outside air temperature detector abnormality detection means 20 are set in advance. The case where the temperature is outside the specified temperature range will be described. At this time, the control method switching means 25 selects the emergency operation means 27 and determines the driving state of each load.

  At this time, the display means 33 identifies the temperature detector in the abnormal state and displays the abnormality, so that the user can quickly recognize the abnormal state and can promptly respond to a repair request or the like. In addition, since a detector in an abnormal state can be identified, maintenance can be improved and repair time can be shortened.

  Hereinafter, the determination of the driving state by the emergency driving means will be described.

  First, when an abnormality of the internal temperature detector is detected by the internal temperature detector abnormality detection means 17, the emergency operation means 27 is detected from the outside air temperature detected by the outside air temperature detector 16 and the current set temperature of the storage room. Driving is performed in a preset operating state of the compressor 1, the evaporator fan 7, and the condenser fan 6. The driving state preset in the emergency driving means 27 is a value obtained by experiment (Table 1).

  Thus, since the compressor, the evaporator fan, and the condenser fan are driven in the specified operation state by the outside air temperature and the set temperature, it is possible to prevent overcooling and temperature rise in the warehouse, Since the internal temperature close to the set temperature can be maintained, the internal temperature detector can improve the food freshness at the time of abnormality, as well as preventing loss due to freezing and spoilage of stored food.

  Further, when the maximum temperature of the compressor 1 due to the condensation temperature is limited during emergency operation when the internal temperature detector fails, the compressor speed during emergency operation is set to a limited upper limit. This suppresses the compressor failure.

  The operation when the condensation temperature detector fails will be described. If the compressor is driven in a state where the condensation temperature detector fails and the condensation temperature cannot be detected, there is a risk that the compressor will fail due to an increase in the condensation temperature. Accordingly, the emergency operation means 27 drives the condenser fan 6 at the maximum rotation to promote heat dissipation of the condenser and suppress an increase in the condensation temperature.

  Further, when the compressor is driven at a high speed when the condensing temperature detector is in a failure state, there is a risk that the condensing temperature will rise excessively, so the upper limit number of rotations obtained by experimenting the compressor (for example, the outside air temperature 35) Excessive temperature rise is suppressed by not driving at a maximum rotation speed of 45r / s) that satisfies the following conditions: As a result, the compressor can be prevented from malfunctioning and the inside of the refrigerator can be kept in a cooled state, so that the stored food can be prevented from being spoiled due to an increase in the internal temperature.

  In addition, when the condensing temperature is high, that is, when the suction pressure of the compressor is high, when the compressor is driven at a low rotation, the compressor may stop due to the compressor stepping out. Do not drive at a lower speed than the lower limit speed obtained in (for example, outside air temperature 35 ° C, internal temperature -18 ° C, internal load and door open / close, minimum rotational speed 35Hz at condensation temperature 60 ° C) Thus, it is possible to prevent the stored food from being spoiled due to the rise in the internal temperature due to the compressor step-out stop.

  A case where the defrosting end detector fails will be described. The defrosting in the case where the defrosting end detector fails is started when the elapsed time from the end of the previous defrosting is the time set in the emergency operation means 27 in advance, and the end is the defrosting control time. The process ends when a time set in advance in the emergency operation means 27 (for example, an outside air temperature of 30 ° C., no opening / closing of the refrigerator door, no defrosting time in the refrigerator) obtained in an experiment has elapsed.

  Thereby, when the defrosting end detector 15 is short-circuited, the cooling capacity is lowered due to the completion of the defrosting immediately after the start of the defrosting, or a longer time than necessary due to the opening failure (for example, provided for safety). 60 minutes of the defrosting forced completion time) The rise in the internal temperature due to energization of the defrosting heater can be prevented.

  Further, as shown in FIG. 4, the compressor 1, the condenser 2, the capillary 3, the evaporator 5, the condenser fan 6, the evaporator fan 7, the defrost heater 8, the internal temperature detector 13, and the defrost end detector 15 In a top mount type refrigerator installed on the top of the refrigerator as a single cooling unit, the internal temperature detector is installed close to the evaporator and defrost heater, so it is affected by the heat during defrosting. Easily, when the temperature detected by the internal temperature detector reaches a set value (for example, 7 ° C) when the defrosting end detector fails, it is configured to stop the defrosting by the emergency operating means. Even in the defrosting control at the time, it is possible to suppress a decrease in cooling capacity due to the remaining frost at the time of defrosting and an increase in the internal temperature at the time of defrosting due to an excessive defrosting time.

  Next, emergency operation when the outside air temperature detector fails will be described. When the outside temperature detector fails to open, the emergency operation means sets the energization rate of the antiperspirant heater to the maximum value (for example, 80%) at the normal time and drives it to drive the external walls 11a to 11d and the threshold walls 12a to 12d of the refrigerator. Sweating can be suppressed with a simple configuration.

  Further, the detected temperature of the condensation temperature detector immediately after the end of the defrosting control is almost equal to the outside air temperature where the refrigerator is installed because the compressor is in a stopped state and is hardly affected by the heat of the compressor and the condenser. . Therefore, if the temperature detected by the condensing temperature detector by the emergency operation means is substituted as the outside air temperature when the outside air temperature detector fails, the energization rate of the sweating prevention heater can be determined at a temperature close to the actual outside temperature, Low power consumption drive is possible even during emergency operation due to the optimal current-carrying rate operation.

  As described above, even when an abnormality occurs in the temperature detector, the present invention can perform emergency operation to prevent freezing of food due to overcooling and food spoilage due to an increase in internal temperature. It can be widely applied to the operation control.

Block diagram of Embodiment 1 of a refrigeration unit and a refrigerator using the same according to the present invention Configuration diagram of cooling cycle of refrigerator of same embodiment Connection diagram of each detector in the same embodiment Front view of the refrigerator according to the embodiment Compressor operating range characteristics diagram according to the embodiment Control block diagram of a conventional refrigerator Conventional refrigerator interior temperature detection means and output voltage characteristics diagram

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Capillary 5 Evaporator 6 Condenser fan 7 Evaporator fan 8 Defrost heater 10 Antiperspiration heater 13 In-case temperature detector 14 Condensation temperature detector 15 Defrost end detector 16 Outside temperature detector 21 Internal temperature detector abnormality detection means 22 Condensation temperature detector abnormality detection means 23 Defrost end detector abnormality detection means 24 Outside air temperature detector abnormality detection means 25 Control switching means 26 Operating state determination means 27 Emergency operation means 28 Compressor drive Means 29 Condenser fan drive means 30 Evaporator fan drive means 31 Defrost heater drive means 32 Antiperspiration heater drive means 33 Display means

Claims (4)

An internal temperature detector that detects the internal temperature of the refrigerator, a condensation temperature detector that is attached to the condenser of the refrigeration cycle and detects the condensation temperature of the refrigerant, and is installed near the evaporator or near the evaporator to detect the end of defrosting A refrigeration unit provided with a defrosting end detector for detecting and an outside air temperature detector for detecting an installation atmosphere temperature of the refrigerator, based on the temperature detected by each temperature detector, a compressor, an evaporator fan, and a condenser Operating state determining means for determining the operating state of a fan, a defrosting heater, a sweating prevention heater, etc., an internal temperature detector abnormality detecting means for detecting an abnormality of the internal temperature detector, and an abnormality of the condensation temperature detector Condensation temperature detector abnormality detecting means for detecting, defrosting completion detector abnormality detecting means for detecting abnormality of the defrosting completion detector, and outside air temperature detector abnormality detecting means for detecting abnormality of the outside air temperature detector And For example, when said at least one of detecting the abnormality of the temperature detector has an emergency operating means for performing an emergency operation, and a control switching means for switching between the emergency operation means and said operating condition determining means, When an abnormality of the outside air temperature detector is detected by the outside air temperature detector abnormality detecting means, the emergency switching means is selected by the control switching means, and the conduction rate of the sweating prevention heater is set to the maximum conduction rate. Refrigeration unit. An internal temperature detector that detects the internal temperature of the refrigerator, a condensation temperature detector that is attached to the condenser of the refrigeration cycle and detects the condensation temperature of the refrigerant, and is installed near the evaporator or near the evaporator to detect the end of defrosting A refrigeration unit provided with a defrosting end detector for detecting and an outside air temperature detector for detecting an installation atmosphere temperature of the refrigerator, based on the temperature detected by each temperature detector, a compressor, an evaporator fan, and a condenser Operating state determining means for determining the operating state of a fan, a defrosting heater, a sweating prevention heater, etc., an internal temperature detector abnormality detecting means for detecting an abnormality of the internal temperature detector, and an abnormality of the condensation temperature detector Condensation temperature detector abnormality detecting means for detecting, defrosting completion detector abnormality detecting means for detecting abnormality of the defrosting completion detector, and outside air temperature detector abnormality detecting means for detecting abnormality of the outside air temperature detector And For example, when said at least one of detecting the abnormality of the temperature detector has an emergency operating means for performing an emergency operation, and a control switching means for switching between the emergency operation means and said operating condition determining means, When an abnormality of the outside air temperature detector is detected by the outside air temperature detector abnormality detecting means, an emergency operation means is selected by the control switching means, and sweating prevention is performed based on the temperature detected by the condensation temperature detector immediately after the defrosting is completed. A freezing and refrigeration unit characterized in that the energization rate of the heater is determined . It has a display means for displaying the operation state of the refrigerator, and when an abnormality has occurred in each temperature detector, the refrigerator is in an emergency operation by identifying the abnormal temperature detector and displaying it on the display means The refrigeration unit according to claim 1 or 2 , wherein a warning is displayed. A refrigerator, wherein the refrigeration unit according to any one of claims 1 to 3 is detachably disposed on an upper part or a side part of a refrigerator body, and a combustible refrigerant is used as a refrigerant.

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