JP2001004261A - Control device of refrigeration show case system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control a refrigerator even if an abnormality occurs in the communication of a show case controller or the refrigerator so that the state of loads cannot be grasped. SOLUTION: The control device 1 is connected to a controller 2 of a plurality of refrigeration show cases and a common refrigerator 5 through a communication line. In the device 1, there are provided a clock mechanism 7 for outputting the present date and hour as season information and an outdoor temperature sensor 8 for detecting outdoor temperatures. When an abnormality occurs in communication, cooling loads are determined by a load judging mechanism 9 based on the season information and outdoor temperature information obtained form the mechanism 7 and sensor 8. The suction pressure set value of the refrigerator 5 is varied based on the cooling loads.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerated showcase such as an open showcase installed in a store, and more particularly to a refrigerated showcase in which a plurality of refrigerated showcases are arranged as a series and their status is monitored and operation commands are issued. The present invention relates to a control device for a system.

[0002]

2. Description of the Related Art As a control device of this kind, a controller (control unit built in each showcase) of a refrigerated showcase (hereinafter simply referred to as a showcase) and a refrigerator are connected by a serial communication line. The load condition is determined based on the state information received from the case and the refrigerator, and the set value of the suction pressure of the refrigerator is changed, and the temperature adjustment set value of the showcase (abbreviated as temperature control set value).
It is known to change or.

[0003]

In such a control device, if an abnormality occurs in communication with the showcase controller, the load status of the showcase cannot be determined. In that case, conventionally, a method of returning the suction pressure set value of the refrigerator to a predetermined initial value has been adopted, but this conventional method cannot obtain sufficient cooling performance depending on load conditions,
There is also a problem that a sufficient energy saving effect cannot be obtained.

An object of the present invention is to centrally control a refrigerated showcase system including a plurality of refrigerated showcases forming one line and one refrigerator common to the refrigerated showcases. A refrigerated showcase control device that is installed and receives a load condition of the refrigerated showcase via a communication line, and changes a suction pressure set value of the refrigerator based on the load condition. The present invention is intended to prevent a problem with the control of the refrigerator when the reception of the status information from the refrigerator becomes impossible.

[0005]

In order to solve the above-mentioned problems, the present invention provides a clock means for outputting a current date and time and an output of the clock means when an abnormality occurs in communication with the refrigerated showcase. Control means for judging the load condition based on the seasonal information obtained from the above, and changing the suction pressure set value of the refrigerator in accordance with the load condition (claim 1). Showcase loads vary from season to season. Therefore, the season is determined from the current date and time (current month, day, and time), and when communication is abnormal, the load status is determined based on the season information, and the suction pressure set value of the refrigerator is changed based on a predetermined reference. For example, in summer, it is determined that the load condition is severe, and control is performed to lower the pressure set value of the refrigerator and increase it in winter.

The present invention also provides an outside air temperature detecting means for detecting the outside air temperature of the refrigerated showcase, and an output from the outside air temperature detecting means when an abnormality occurs in communication with the refrigerated showcase. Control means for judging the load condition based on the outside air temperature information and changing the suction pressure set value of the refrigerator in accordance with the load condition (claim 2). The load on the showcase varies depending on the outside temperature. Therefore, the load situation is determined based on the detected outside temperature,
The suction pressure set value of the refrigerator is changed based on a predetermined criterion. That is, when the outside air temperature is high, it is determined that the load condition is severe, and the pressure set value of the refrigerator is decreased, and when it is low, the control is increased.

According to a third aspect of the present invention, the timepiece means according to the first aspect and the outside air temperature detecting means according to the second aspect are provided side by side, and when an abnormality occurs in communication with the refrigerated showcase, the timepiece means is provided. The load state of the showcase is determined based on the seasonal information and the outside air temperature information obtained from the above, and control is performed to change the suction pressure set value of the refrigerator according to the load state. In this case, if a switch is provided to select in advance which of the seasonal information and the outside air temperature information should be used to determine the load status when a communication error occurs, according to the installation environment of the showcase or the refrigerator, Whether the load is determined from one of the seasonal information and the outside temperature information,
It is possible to select whether to judge the load from two pieces of information (claim 4). For example, if the refrigerator is installed in an environment that is less affected by the season, such as an air-conditioned indoor, it may be better to judge the load only from the outside temperature, while the showcase is located near the entrance of the store. If it is installed in an environment where the outside air temperature fluctuates greatly, it may be better to judge the load based only on the seasonal conditions.

[0008]

FIG. 1 is a system block diagram showing an embodiment of the present invention. In FIG. 1, a control device 1 controls a plurality of showcases forming one system, and a controller 2 (2-1, 2-2, 2-1) of each showcase.
, 2-3,...), The control unit 3 makes a request for output of the state information of the showcase at a constant period, for example, every 30 seconds. The controller 2 outputs the current status information of each showcase in response to the request, and the control device 1 receives the output status information. Requests and receptions of these data are performed by serial communication between a communication interface (not shown) of each controller 2 and a showcase communication interface 4 of the control device 1. The state information of the showcase output from the controller 2 includes temperature information such as a temperature of blowing out circulating cool air, operation information such as during defrosting, presence / absence of an alarm output, and an ON / OFF state of an electromagnetic valve of the refrigerant circuit. Have been.

The plurality of showcases are cooled by one common refrigerator 5, and the control device 1 requests the refrigerator 5 to output status information. The refrigerator 5 outputs current state information in response to a request, and the control device 1 receives the output state information. Request and reception of these data are performed by the refrigerator 5
Is performed by serial communication between a communication interface (not shown) and the refrigerator communication interface 6 of the control device 1. The state information output from the refrigerator 5 includes operation information such as a suction pressure value and restarting. The refrigerator 5 is controlled at a variable speed by inverter drive, and the refrigerating capacity is adjusted according to the load condition.

The control unit 3 turns on / off the solenoid valve of the showcase.
Based on the OFF information, the ON time ratio of the solenoid valve for a certain period of time, for example, 30 minutes, is calculated to determine the load state of the showcase, and the suction pressure set value is updated to the refrigerator 5 so as to output according to it. Send the quantity. There are a method of instructing the absolute value of the pressure set value and a method of instructing the shift amount in updating the pressure set value. Here, the shift amount is instructed. The refrigerator 5 operates so as to eliminate the deviation between the received suction pressure set value and the suction pressure value measured by a pressure sensor (not shown) to change the refrigerating capacity.

The control unit 3 determines whether the current cooling load of the showcase is overloaded on the refrigerator 5 based on the temperature information from the controller 2 and the pressure information from the refrigerator 5. Then, a change value of the temperature control set value is transmitted to the controller 2 according to the load state. For example, when the circulating cool air temperature of the showcase exceeds a certain limit value and the deviation between the measured value of the suction pressure of the refrigerator 5 and the set value is not eliminated for a certain period of time or more, it is determined that an overload condition has occurred. The temperature control set value is increased by, for example, 1 ° C., and the load on the refrigerator 5 is reduced. The controller 3 transmits the changed value to the controller 2 again after a certain period of time has elapsed after transmitting the changed value of the temperature control set value to the controller 2 to return the temperature control set value to the value before the change.

Here, the control device 1 includes a clock mechanism 7 for counting the current date and time, an external temperature sensor 8 for detecting the temperature outside the showcase, and a load for reading the outputs of these to determine the load status of the showcase. A judgment mechanism 9 and a pressure control system selection switch 10 are provided. As described above, the controller 4 controls the controller 2 of each showcase.
Also, the status information is serially requested and received from the refrigerator 5, the load condition is determined, and the suction pressure set value and the temperature control set value are transmitted to the refrigerator 5 and the controller 2; When the reception of the state information from the controller 2 is interrupted, the operation command to the refrigerator 5 according to the load condition of the showcase becomes impossible.

In this case, according to the present invention, the load is determined based on the seasonal information obtained from the output of the clock mechanism 7 (current date and time) and the outside temperature information obtained from the output of the outside temperature sensor 8 (temperature outside the showcase). The determination mechanism 9 determines the load status of the showcase. FIG. 2 shows an example of a load determination criterion based on seasonal information (current month, day, and time) and the outside air temperature, and is set in the load determination mechanism 9 in advance. FIG.
, The cooling load of the showcase is determined to be large, medium, or small based on the time (month), time (day or night), and whether the outside air temperature is higher or lower than 15 ° C., for example. When a communication error with the showcase controller 2 occurs, the control unit 3 instructs the refrigerator 5 to change the suction pressure set value to a predetermined reference value according to the load determination.
Thus, even when the load determination based on the reception of the state information from the controller 2 becomes impossible, the refrigerator control according to the actual load can be continuously performed.

FIG. 2 shows a case in which the load is determined based on both the season information and the outside temperature information. However, depending on the installation conditions of the showcase, the refrigerator 5 and the outside temperature sensor 8, only the season information or the outside temperature information is used. It is also possible to determine the load based on the load. For example, when the refrigerator 5 is installed not indoors but indoors without a sense of season, seasonal information is unnecessary. Also, when the showcase is installed near the entrance of the store and the fluctuation of the outside temperature around the store is large. In some cases, it may be better to judge the load only with seasonal information. Pressure control system selection switch 10
In such a case, the load is determined in advance based on both the seasonal information and the outside air temperature information or the load is determined based on either of the information by manual switching.

For example, as shown in FIG. 3, the selection switch 10 is set to “environmental condition”, “seasonal condition”, “outside air temperature condition”.
It is possible to switch to the three positions. When communication is normal, the load is determined based on the received state information regardless of the switching position. However, when communication is abnormal, according to the switching position,
As shown in the figure, the load is determined based on the information on the date and time, the outside temperature, only the date and time, and only the outside temperature. The load determination criterion based on only the season information or the outside temperature information is separately set in the load determination mechanism 9 as in FIG. The control unit 3 selects a load determination criterion according to the switching position of the selection switch 10 and instructs the refrigerator 5 to change the suction pressure set value.

In FIG. 1, the control device 1 includes other mechanisms, which will be described below. First, the temperature control temperature changing mechanism 11 and the setting input mechanism 12
Is provided. The operator sets and inputs the change value of the temperature control set value and the change execution time to the temperature control temperature change mechanism 11 via the setting input mechanism 12 when the operator determines that it is necessary based on an empirical rule. If the operator inputs immediately to change the temperature control set value, the temperature control temperature change mechanism 1
1 immediately transmits the changed value to the controller 2.
When the operator inputs to execute at the designated time, the temperature adjustment temperature changing mechanism 11 sends the changed value when the time from the clock mechanism 7 reaches the designated time, and returns the original value after a fixed time. In addition, whether to return to the original state after a certain time can be selected.

Further, in FIG. 1, the control device 1 is provided with a defrost control mechanism 13, and an operator inputs a defrost start time and a defrost forced end time from the setting input mechanism 12 to the defrost control mechanism 13. I do. When the time output from the clock mechanism 7 reaches the set time, the defrost control mechanism 13 transmits a defrost start signal to the controller 2 via the communication switching mechanism 19 and the showcase communication interface 4. Also, after a certain time has passed since the transmission of the defrost start signal, a defrost release signal is transmitted in the same manner. The end of the defrosting operation is normally performed for each showcase by the judgment of the controller 2 based on the temperature signal from the defrosting thermostat. However, if the defrosting operation is continued for a certain period of time due to some trouble, the control device The operation is forcibly terminated by the defrosting release signal from step 1.

Further, in FIG. 1, the control device 1 is provided with a control mechanism 14 when the refrigerator is abnormal. The refrigerator abnormal state control mechanism 14 monitors the state information of the refrigerator 5 received by the control unit 3 and, when the state of the refrigerator 5 becomes abnormal or restarting, sends a forced cooling stop command to the controller 2. Send to Further, when the state such as the abnormality is resolved, a forced cooling stop release command is transmitted.

Further, in FIG. 1, the control device 1 is provided with a refrigerator pressure display mechanism 15 and a pressure display 16. The refrigerator pressure display mechanism 15 receives the pressure information of the refrigerator 5 received by the control unit 3 and displays the operating pressure and the pressure set value on the pressure display 16 at regular intervals. The operator confirms this display and changes the display method of the product as necessary to reduce the load on the refrigerator.

On the other hand, in FIG. 1, 17 (17-1, 1
7-2, 17-3,...) Are external devices, and an external device communication interface 18 and an external device communication relay mechanism 20 are provided in the control device 1. In the external device 17,
There are a defrost timer, a defrost controller, a data collection device, a centralized control panel, and the like. The external device 17 transmits the output request of the state information to the showcase to the external device communication interface 18 with its own address information, and the external device communication interface 18 transmits the output request received from the external device 17 to the communication switching mechanism 19. send. Communication switching mechanism 19
Sends the output request received from the external device communication interface 18 to the external device communication relay mechanism 20, and the external device communication relay mechanism 20 outputs the requested information from the showcase state information stored in the control unit 3. The address of the transmission destination is attached and transmitted to the communication switching mechanism 19. The communication switching mechanism 19 distributes the request information to the external device communication interface 18 based on the address. In this way, the status information of the showcase requested by the external device 17 is transmitted to the external device 17 via the external device communication interface 18.
Is output to The external device 17 receives only information with its own address.

[0021]

As described above, according to the present invention, the clock means for outputting the current date and time as seasonal information and the outside air temperature detecting means for outputting the outside air temperature information are provided, and a communication abnormality with the showcase controller occurs. In such a case, by judging the load condition based on the seasonal information and the outside air temperature information and instructing the refrigerator to change the suction pressure set value, the appropriate refrigerator control is maintained even when communication is abnormal, It is possible to achieve sufficient cooling performance and energy saving effect. Further, by providing a switch for selecting whether to determine the load based on the season information or the outside temperature information, more appropriate control according to the installation conditions of the showcase or the refrigerator can be realized.

[Brief description of the drawings]

FIG. 1 is a system block diagram of a control device showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of determining a cooling load when communication is abnormal.

FIG. 3 is a diagram showing a selection example of a pressure control method when communication is abnormal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control apparatus 2 Showcase controller 3 Control part 4 Showcase communication interface 5 Refrigerator 6 Refrigerator communication interface 7 Clock mechanism 8 Outside air temperature sensor 9 Load judgment mechanism 10 Pressure control system selection switch

Claims (4)

[Claims] 1. A refrigeration showcase system for centrally controlling a refrigeration showcase system comprising a plurality of refrigeration showcases forming one system and one refrigerator common to these refrigeration showcases, A control device for a refrigeration showcase system that receives a load status of a case via a communication line and changes a suction pressure set value of the refrigerator in accordance with the load status. When an error occurs in communication with the showcase, the load condition is determined based on seasonal information obtained from the output of the clock means, and the suction pressure set value of the refrigerator is changed according to the load condition. A control device for a refrigerated showcase, comprising a control unit. 2. A refrigerated showcase system for centrally controlling a refrigerated showcase system comprising a plurality of refrigerated showcases constituting one series and one refrigerator common to these refrigerated showcases, A control device for a refrigerated showcase system that receives a load status of a case via a communication line and changes a suction pressure set value of the refrigerator in accordance with the load status, wherein a temperature outside the refrigerated showcase is detected. When an abnormality occurs in the communication between the outside air temperature detection unit and the refrigerated showcase, the load condition is determined based on the outside air temperature information obtained from the output of the outside air temperature detection unit. A control unit for changing a set value of the suction pressure of the refrigerator. 3. A refrigeration showcase system for centrally controlling a refrigeration showcase system comprising a plurality of refrigeration showcases forming one series and one refrigerator common to these refrigeration showcases, A control device for a refrigeration showcase system that receives a load status of a case via a communication line and changes a suction pressure set value of the refrigerator in accordance with the load status. Outside temperature detection means for detecting the temperature outside the showcase; and seasonal information obtained from the output of the clock means and output from the outside temperature detection means when an abnormality occurs in communication with the refrigerated showcase. Control means for judging the load condition on the basis of the outside air temperature information obtained, and changing a suction pressure set value of the refrigerator in accordance with the load condition. Control device for warehouse showcase. 4. A refrigeration show according to claim 3, further comprising switch means for preliminarily selecting which of said seasonal information and outside air temperature information is to be used when communication is abnormal. Case control device.