JP2000241068A - Pressure-controlling device for refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily set and confirm pressure, and to operate a refrigerating machine in an optimum state according to the operation state of a showcase or the like. SOLUTION: A refrigerating machine can change the pressure display of a display part for digitally displaying a low pressure, a high pressure, intake gas temperature, and a setting pressure from a conventional unit to an SI one. Also, a pressure-controlling device 8 is connected to a monitor control panel 2 of a centralized monitoring device 1 for controlling a showcase 6 or the like via a serial transmission line 4, and operation information and a change command can be transmitted and received between the monitor control panel 2 and the pressure-controlling device 8. In this case, the operation information includes the operation pressure of the refrigerating machine 9, the operation state of a compressor, and the setting pressure of the refrigerating machine 9 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

The present invention relates to a refrigerator pressure control device,
Specifically, while improving the display of the operating state of a refrigerator provided in a refrigerator or a refrigerator, such as a showcase, the pressure of the refrigerator can easily and effectively change the setting of the operating pressure of the refrigerator. It relates to a control device.

[0002]

2. Description of the Related Art As a method of controlling the operating pressure of a refrigerator such as a refrigeration / refrigeration showcase or the like which is installed in a large number of supermarkets or the like, a cut-in / cut-out is performed for each compressor by a mechanical pressure switch or an electronic pressure switch. Cutout pressure was set. Furthermore, since the change of the set pressure is performed on the refrigerator side, the work of changing the set value has to be performed in the machine room where the refrigerator is installed. When the pressure set value is changed between nighttime and daytime, a pressure switch for night operation is provided separately from the pressure switch for daytime operation, and both pressure switches are switched by a timer for use.

[0003]

Therefore, not only is the work of changing the pressure set value troublesome, but also, in particular, when changing the set pressure or monitoring the operating state, the display unit of the pressure shifts to the SI unit. The conventional display unit "kg / cm
²⁾ was changed to [MPa] in SI units, so there was a great sense of discomfort with the displayed values. If multiple refrigerators were installed, the conventional pressure display and the pressure display in SI units May be mixed, causing confusion.

The operation of the compressor is controlled by setting a pressure switch so that the compressor is operated when the low pressure rises to the cut-in pressure and is stopped when the pressure drops to the cut-out pressure. . For this reason, once the operating pressure is set, the refrigerator is operated at a fixed pressure throughout the year irrespective of the load fluctuation of a showcase or the surrounding environment such as the season, so that the capacity of the refrigerator cannot be properly controlled. Was. As a method of determining whether or not the capacity of the refrigerator is appropriate for the showcase, a determination is made based on the duty ratio of the solenoid valve of the showcase, but whether the showcase is properly cooled is performed. I couldn't tell if it was.

Accordingly, the present invention provides a refrigerator pressure control device that can easily set and check the pressure and can operate the refrigerator in an optimal state according to the operating conditions of a showcase or the like. It is intended to provide.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, a pressure control device for a refrigerator according to the present invention controls a compressor of the refrigerator by a pressure value measured by a pressure sensor. Wherein a display unit for digitally displaying low pressure pressure, high pressure pressure, suction gas temperature and set pressure is provided, and the pressure display of the display unit is formed so as to be switchable between a conventional unit and an SI unit. Is what you do.

[0007] In particular, the pressure control device has a transmission / reception unit connected via a serial transmission line to a monitor control panel of a centralized monitoring device for controlling the operation of refrigeration equipment such as a showcase. Operating information and commands, such as the operating pressure of the refrigerator, the operating state of the compressor, and the set pressure of the refrigerator, can be transmitted and received between the control panel and the pressure control device via the serial transmission line. Further, the pressure control device is formed so as to be able to change the operating pressure set value of the refrigerator by a command from the monitor control panel, and the pressure control device is provided on the monitor control panel The operating pressure set value of the refrigerator can be changed according to a predetermined time schedule by a clock function. Further, the monitor control panel is capable of controlling loads on refrigeration equipment such as a plurality of showcases,
A cooling state is monitored, and a low-pressure operating pressure setting change signal for maintaining an operating pressure of the refrigerator in an optimum state according to the cooling state is output to the pressure control device.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a system diagram showing an example of a system configuration using the pressure control device of the present invention. This system includes an operating state of a showcase 6 such as an open showcase or a walk-in refrigerator via a temperature control device 5 connected to input / output units 3a to 3f of a monitor control panel 2 of a centralized monitoring device 1 via a serial transmission line 4. While controlling the change of various set values while monitoring the operation state of the refrigerator 9 via the pressure control device 8 also connected via the serial transmission line 7. It is formed to perform.

The monitor control panel 2 has external output units 10a to 10a for controlling various devices such as lights and air conditioners.
An input unit 11 and the like for receiving signals such as d and electric energy are provided. The monitor control panel 2, like the monitor control panel of the conventional centralized control device, stores various preset values and information such as the internal temperature sent from the temperature control device 5 of the showcase 6. Showcase 6 based
Is kept in an optimal cooling state, and the showcase 6
And other devices can be controlled in the same manner as in the related art.

On the other hand, a pressure control device 8 provided in the refrigerator 9 is an electronic pressure control device in which various electronic components are housed in a casing 21 having an external appearance as shown in FIG. A data display unit 22 is provided on the front of the unit 21 and is used to connect input / output wiring for the serial transmission line 7, power supply, compressor output, defrost input, alarm output, heater output, alarm input, and the like. A group of terminals 23 and 24, a dip switch 25 for performing basic settings, the pressure control device 8
Address setting switch 26, low pressure sensor connection terminal 27, high pressure sensor connection terminal 28, temperature sensor connection terminal 29, display changeover switch 30, alarm reset button 31, alarm code button 32, data setting button 33, forcible operation A switch 34 is provided at a predetermined position.

As shown in FIG. 3, the display unit 22 has a data display window 41 for displaying numerical values of pressure and temperature, and three units L indicating the units of the numerical values displayed on the data display window 41.
ED (conventional unit [kg / cm ² ], SI unit [MPa], temperature [° C.]) 42a, 42b, 42
c, three display LEDs (low pressure, high pressure, suction gas temperature) 43a, 43b, 43c indicating the type of data displayed on the data display section 41, and control of a plurality of compressors (compressors). Compressor control LED group (No. 1 to No. 4) 4 indicating the number of the compressor in the case
4, further, various driving information, for example, cut-in display,
An LED group 45 including LEDs for cutout display, oil back stop display, defrost display, vacuum operation display, alarm display, remote display, and liquid back display is provided.

The data displayed in the data display window 41 can be arbitrarily switched by switching the display changeover switch 30, and the pressure can be displayed by switching between the conventional unit and the SI unit. One of the unit LEDs 42a and 42b is turned on in response to the switching of the display.

Further, display LEDs 43a, 43b, 43
c, according to the type of data displayed in the data display window 41, when the data displayed in the data display window 41 indicates a low pressure, the low pressure display LED 43a is lit,
Similarly, when the data display window 41 is displaying high pressure, the high pressure display LED 43b is lit, and when displaying the suction gas temperature, the suction gas temperature display LED 43c is lit.

When the pressure drops to 0 MPa or less, the LED group 45 turns on the vacuum operation indication LED,
Cutout LED from MPa to cutout pressure
Lights up, goes out from the cut-out pressure to the cut-in pressure, that is, goes out during normal operation, and the cut-in LED lights up when the cut-in pressure is exceeded.

Further, when the defrost operation is performed, the defrost display LED is displayed, when the forcible stop is performed during the oil back control, the oil back stop display LED is displayed, and when an alarm is issued, the alarm display LED is displayed. The liquid back display LED lights up when backing occurs, and the remote display LED lights up during remote control from the monitor control panel 2. Therefore, the operating state of the refrigerator 9 can be easily known by looking at the numerical value displayed in the data display window 41 of the display unit 22 and the lighting state of the LED. In particular, the display of the pressure displayed on the data display window 41 is expressed in the conventional unit [kg / c
m ² ] and [MPa], which is the SI unit, can be arbitrarily switched and displayed, so that the pressure can be easily and reliably confirmed, and in the transition period from the conventional unit to the SI unit. Confusion can be minimized.

The pressure control device 8 thus formed
Is provided so as to be connected to the monitor control panel 2 of the centralized monitoring device 1 via the serial transmission line 7 so that data can be transmitted and received between the pressure control device 8 and the monitor control panel 2. Refrigerator 9 input to pressure control device 8
The operating state of the compressor 9 such as the operating pressure of the compressor and the oil bag and the liquid bag can be transmitted to the monitor control panel 2, and the state of the refrigerator 9 can be collectively managed by the monitor control panel 2. Further, various conditions set in the pressure control device 8 are set by the monitor control panel 2 and transmitted to the pressure control device 8 through the serial transmission line 7 so that the set pressure value and the like can be set by the monitor control panel 2. This makes it possible to change the set pressure in the plurality of refrigerators 9 from the monitor control panel 2 at once without going to the machine room where the refrigerators 9 are installed. Moreover, by using the clock function of the monitor control panel 2 and setting a time schedule for automatically changing the operating pressure set value of the refrigerator 9, the optimal operating pressure according to the day and night or seasonal load fluctuations can be obtained. The refrigerator 9 can be operated.

Further, based on information such as the internal temperature of the showcase 6 input to the monitor control panel 2, a pressure control device 8 is provided.
, The operating state of the refrigerator 9 can be changed. FIG. 4 shows a flowchart for performing this control. First, in step S1, a temperature difference (inside temperature-set temperature) T between the detected internal temperature and the set temperature is compared with a preset lower limit set temperature Tmin, and the temperature difference T is set to be lower than the lower limit set temperature Tmin. When the temperature is low, that is, when the temperature in the refrigerator is lower than the lower limit temperature and the temperature in the refrigerator is too cold,
Proceeding to step S2, the operating pressure set value is shifted up. In step S3, the temperature difference T is compared with a preset upper limit set temperature Tmax. If the temperature difference T is higher than the upper limit set temperature Tmax, that is, if the internal temperature is higher than the upper limit temperature, If the cooling is insufficient, the process proceeds to step S4 to shift down the operating pressure set value. If the conditions in steps S1 and S3 are not satisfied, the flow advances to step S5 to hold the current set value.

As described above, when the internal temperature is low, the operating efficiency of the refrigerator 9 can be improved by increasing the operating pressure to increase the evaporation temperature. When the internal temperature is high, the showcase 6 can be cooled to a predetermined temperature by lowering the operating pressure to lower the evaporation temperature.

Changing the operating pressure set value as described above can be performed by inputting various conditions into the monitor control panel 2. FIG. 5 shows an example of a screen display when setting various conditions for automatically changing the low pressure setting value. When changing the pressure set values of a plurality of refrigerators, the address of the pressure control device 8 may be selected on a screen different from this screen.

First, the setting target display 51 displays "LP" meaning low pressure. The next shift setting display 52 shows the upshift value and downshift value in steps S2 and S4 described above. Here, it is displayed that the shift pressure is set to “shift = 0.01 MPa”. I have. This shift pressure is 0.01
It can be performed in 0.01 units in the range of -0.05 MPa, and 0.01 MPa is set as an initial value. This set value may be a value common to showcases for low-temperature use and medium-temperature use.

The medium temperature setting 53 is a medium temperature application (the cut-in set pressure of the refrigerator> 0.10MP) which is a specification of meat or fresh fish.
This indicates the maximum shift-up value in the case of a), and is 0.0
It can be performed in 0.01 units in the range of 1 to 0.10 MPa, and the initial value is 0.10 MPa (“Mid = 0.1
0 MPa ”).

The low-temperature setting 54 is for low-temperature applications such as refrigeration or ice specifications (cut-in set pressure of refrigerator: 0.10 MPa
This indicates the maximum shift-up value in the case of a), and is 0.0
It can be performed in 0.01 unit within the range of 1 to 0.10 MPa. In this low-temperature specification, since the temperature inside the refrigerator may become unstable when shifting up, the maximum shift-up value is set to a relatively low 0.06 MPa (“Low = 0.06MPa”).
a)) as an initial value.

The totaling time setting 55 indicates the totalizing time of the average value of the internal temperature of the showcase. The average of the internal temperature of the refrigerator is excluded except during defrost where the internal temperature is not stable or 30 minutes after the end of the defrost. The time to calculate the value is set. The setting range can be set in the range of 0 to 120 minutes in units of minutes, and 60 minutes (“Ave = 60 m”) is set as an initial value.

The interval setting 56 indicates an interval time for performing a shift-up or a shift-down. When a shift-up or a shift-down is performed,
The next shift-up or shift-down is performed after the time set here, thereby preventing frequent shift-up or shift-down. 60 minutes (“Int = 60 m”) is set as the initial value, and
It can be set in minutes in the range of 0 minutes.

The upper limit value display 57 indicates the upper limit value (the upper limit set temperature Tmax in the step S3) when shifting down the cut-in and cut-out set values, and the initial value is 0.5 ° C. (“MAX”). = 0.5 ° C ”), and can be set in the range of 0 to 5.0 ° C in 0.1 ° C units.

The lower limit value display 58 indicates a lower limit value (lower limit set temperature Tmin in the step S1) when shifting up the cut-in and cut-out set values, and 0.0 ° C. (“MIN”) as an initial value. = 0.0 ° C ”), and can be set in 0.1 ° C units in the range of 0 to 5.0 ° C.

By performing the control as shown in FIG. 4 in such a setting, it is possible to always operate the refrigerator 9 at an optimum operating pressure according to the load fluctuation of the showcase 6 and the surrounding environment. Become. Note that while the refrigerator 9 is performing the suction override, the above control is invalidated, the suction override is performed with priority, and the pressure is increased to increase the evaporation temperature. As the lower limit of the downshift, a low pressure set value set separately is used.

[0028]

As described above, according to the showcase centralized monitoring device of the present invention, the pressure display of the pressure control device can be switched between the conventional unit and the SI unit, so that the pressure can be confirmed without fail. It can be carried out. In addition, by connecting the monitor control panel of the centralized monitoring device via a serial transmission line, the operating state of the refrigerator can be monitored by the monitor control panel, and the operating pressure set value of the refrigerator can be changed by the monitor control panel. Becomes possible. In addition, by using the clock function of the monitor control panel, the refrigerator can be operated on a time schedule corresponding to day and night or seasonal load fluctuation. In particular, it becomes possible to operate the refrigerator in an optimal state according to the operating state of the showcase or the like input to the monitor control panel. Therefore, the number of pressure switches installed in the refrigerator can be reduced, a timer is not required, and the wiring can be simplified, so that the equipment cost can be reduced. Further, since the refrigerator can be operated in an optimal state, the power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an example of a system configuration using a pressure control device of the present invention.

FIG. 2 is a front view of the pressure control device.

FIG. 3 is a front view of a display unit.

FIG. 4 is a flowchart illustrating a control example of a pressure control device by a monitor control panel.

FIG. 5 is a front view showing a display example of a condition setting screen.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Central monitoring apparatus 2 Monitor control panel 3a-3f Input / output part 4 Serial transmission line 5 Temperature control device 6 Showcase 7 Serial transmission line 8 Pressure control device 9 Refrigerator 10a-10d External output part 11 Input part 21 Housing 22 Data Display unit 23, 24 Terminal group 25 Dip switch 26 Address setting switch 27 Low pressure sensor connection terminal 28 High pressure sensor connection terminal 29 Temperature sensor connection terminal 30 Display switch 31 Alarm reset button 32 Alarm code button 33 Data setting button 34 Forced operation switch 41 Data display windows 42a, 42b, 42c Unit LEDs 43a, 43b, 43c Display LEDs 44 Compressor control LED group 45 LED group 51 Setting target display 52 Shift setting display 53 Medium temperature setting 54 Low temperature setting 55 Total time setting 56 Interface Bal set 57 upper limit value display 58 lower limit value display

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Setsu Nozawa 2-15-4 Shibaura, Minato-ku, Tokyo Nakano Refrigerator Co., Ltd. F-term (reference) 3L045 AA02 AA04 BA01 CA02 DA01 LA11 LA16 LA18 MA01 MA09 NA00 PA02 PA03 PA04

Claims (5)

[Claims] 1. A refrigerator pressure control device for controlling a compressor of a refrigerator by a pressure value measured by a pressure sensor, wherein a display unit for digitally displaying a low pressure, a high pressure, a suction gas temperature and a set pressure is provided. A pressure control device for a refrigerator, wherein a pressure display of the display unit is formed so as to be switchable between a conventional unit and an SI unit. 2. The pressure control device has a transmission / reception unit connected via a serial transmission line to a monitor control panel of a centralized monitoring device for controlling the operation of a refrigeration equipment such as a showcase. Operating information and commands such as the operating pressure of the refrigerator, the operating state of the compressor, the set pressure of the refrigerator, etc., can be transmitted and received between the panel and the pressure control device via the serial transmission line. The pressure control device for a refrigerator according to claim 1, wherein: 3. The pressure control device for a refrigerator according to claim 2, wherein the pressure control device is configured to be able to change an operation pressure set value of the refrigerator according to a command from the monitor control panel. . 4. The pressure control device according to claim 1, wherein a set value of an operation pressure of the refrigerator is changeable according to a predetermined time schedule by a clock function provided in the monitor control panel. Item 3. A pressure control device for a refrigerator according to Item 2. 5. The low-pressure operating pressure for monitoring the load and the cooling state of the refrigeration equipment such as a plurality of showcases and maintaining the operating pressure of the refrigerator in an optimum state according to the cooling state. The pressure control device for a refrigerator according to claim 2, wherein the pressure change device is configured to output a setting change signal to the pressure control device.