JP3384655B2 - Cold storage - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low temperature warehouse provided with a refrigerant circuit, and more particularly to a low temperature warehouse capable of detecting refrigerant leakage from the refrigerant circuit.

[0002]

2. Description of the Related Art Conventionally, this type of low-temperature storage has a cooler for a refrigerant circuit provided in the inside of a heat-insulating box, as disclosed in, for example, Japanese Patent Laid-Open No. 3-70962 (F25D11 / 00). The operation of cooling the inside of the refrigerator or freezing the regenerator or the like was performed. In particular, in a low-temperature warehouse used for distribution of low-temperature foods or the like as described in the above publication or a large-sized low-temperature warehouse, a two-system refrigerant circuit may be attached in order to freeze the cold storage agent or sufficiently cool a large interior. .

[0003]

When a refrigerant leaks from one of the refrigerant circuits of the low temperature refrigerator, the inside of the refrigerator is not operated because the cooler of the other refrigerant circuit is performing the cooling action. Is cooled to some extent. Therefore, in addition to delaying the discovery of such refrigerant leakage, insufficient cooling eventually leads to poor cooling, and an excessive load is applied to the normal refrigerant circuit, so that the refrigerant circuit is also fatal. There was a problem that it would lead to a major failure.

On the other hand, in the case of a low temperature warehouse provided with two systems of refrigerant circuits as described above, a sensor is connected to the control device to compare the temperatures of a normal refrigerant circuit and an abnormal refrigerant circuit, Although it is possible to detect a leak, when the refrigerant circuit is single, such a comparison cannot be performed, and therefore it is necessary to remove the refrigerant leak detection function from the control device.

In view of the above conventional situation, it is an object of the present invention to easily enable / disable the refrigerant leakage detection function according to individual characteristics in a low temperature warehouse equipped with a refrigerant circuit. And

[0006]

According to another aspect of the present invention, there is provided a low-temperature storage device having a refrigerant circuit, wherein a controller for detecting a refrigerant leak from the refrigerant circuit is connectable. This control device has a setting switch for setting the refrigerant leakage detection function, and when the function is set to be invalid by this setting switch, the refrigerant leakage detection operation from the refrigerant circuit is stopped and set. When the refrigerant leakage detection function is set to be effective by the switch, the refrigerant leakage detection operation is executed while the sensor is connected.

In the above, the low temperature refrigerator of the invention of claim 2 is:
The control device has a function of detecting an abnormality of the sensor connected to the control device, and when the refrigerant leakage detection function is effectively set by the setting switch, the abnormality detection operation of the sensor for detecting the refrigerant leakage is performed. When the function is disabled, the abnormality detection operation of the sensor is stopped.

In the above, the low temperature refrigerator of the invention of claim 3 is:
When the control device includes a display device and the refrigerant leakage detection function is enabled by the setting switch, the display device performs data display regarding the sensor for detecting the refrigerant leakage, and when the function is disabled. Has
Data display regarding the sensor is prohibited.

In the above, the low temperature refrigerator of the invention of claim 4 is:
The control device is provided with an operation panel provided with a plurality of switches for instructing the operation of the control device and a display device, and the control device always performs a normal display on the display device, and the normal operation of the display device based on the operation of the switch. Instead of the display, the mode shifts to a check mode in which data related to the sensor is displayed.

According to the fifth aspect of the present invention, there is provided the low temperature chamber as described above.
The control device shifts to the check mode when two or more switches are simultaneously operated.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a perspective view of a low temperature storage R of the present invention, and FIG. 2 shows a vertical side view of the low temperature storage R. In the delivery base, the cold storage R of the embodiment receives the supply of AC power to operate the compressor, freezes the cold storage agent while cooling the storage chamber, stores items such as food, and then disconnects from the power source. It is a low-temperature warehouse for physical distribution, which is loaded on the bed of a delivery vehicle such as a truck and cools stored articles by an endothermic action of a cold storage agent during the delivery.

The cold storage R is a body 1 made of a heat insulating box.
A storage chamber 2 for storing articles formed in the main body 1, a door 3 for opening and closing the storage chamber 2 (not shown in FIG. 2),
The cold storage chamber 4 communicates with the storage chamber 2 via a duct 5, a cold storage agent 6 stored in the cold storage chamber 4, and a cooling device 7 for cooling the cold storage agent 6.

The cooling device 7 is composed of two systems of refrigerant circuits C1 and C2 as shown in FIG. Each of the refrigerant circuits C1 and C2 has a compressor 8, a condenser 12, a capillary tube 11, and a roll bond type cooler 10.
And the accumulator 9 and the like, and the cooler 10 is arranged in the cool storage chamber 4 so as to be in thermal contact with the cool storage agent 6.

Here, the cooler 10 includes both refrigerant circuits C1 and C.
Two of them are installed in total, six are arranged in close contact with each other so as to sandwich the cool storage agent 6, and thereafter, the cooler of the refrigerant circuit C1 is 10A ..., The cooler of the refrigerant circuit C2 is 10B ... . This cooler 10A ... 10B ... And the regenerator 6
The cool air cooled by the DC fan motor 14
It is sent to the storage room 2 via the duct 5.

The air in the storage chamber 2 flows from the suction port 15 into the cold storage chamber 4
The cool air from the cold storage chamber 4 is blown into the storage chamber 2 through the outlet 16 of the duct 5. A cool storage sensor 17 that detects the temperature is attached to the cool storage agent 6 that is in close contact with the cooler 10A of the refrigerant circuit C1. Further, the outlet 16 is provided with an in-compartment sensor 18 which will be described later and detects the temperature of the cool air blown into the storage chamber 2. Further, 19 is a gas leak sensor, which is provided so as to detect the temperature of the cold storage agent 6 that is in close contact with the cooler 10B of the refrigerant circuit C2.

A caster 20 is attached to the bottom of the main body 1, and a handle 21 is attached to the door 3.
A machine room 22 is formed in the lower rear corner of the main body 1 and houses the compressors 8 and 8 of the refrigerant circuits C1 and C2 and a battery (storage battery) not shown. Further, an AC power supply input section 23 having a built-in plug is formed on the left side of the front surface of the main body 1, and an operation panel 24 is provided below the AC power supply input section 23.

On the operation panel 24, as shown in FIG. 5, the display unit 2 as a display device composed of 7-segment LEDs.
6, a refrigerating temperature selecting switch 27 for selecting a temperature as a switch for instructing an operation to a control device to be described later, a freezing temperature selecting switch 28, and LEDs 43, 44 for displaying the selection states thereof, and above them. Freezing LED29, Freezing completion LED31, In-fridge cooling L
The ED 32, the refrigerator switch 33, and the like are arranged.

Next, FIG. 6 shows a controller 36 of the cold storage R. The control device 36 is provided in, for example, an electric equipment box (not shown) provided in the machine room 22 or the like, and includes a general-purpose microcomputer 37. The input of the microcomputer 37 includes the cold storage sensor 17,
The in-compartment sensor 18 and the gas leak sensor 19 are connected. Further, the microcomputer 37 includes the condenser 1
Filter sensor 38 for detecting clogging of the second filter
Also, a battery sensor 39 for detecting the state of charge of the battery is also connected.

Further, the inputs of the microcomputer 37 are connected to the respective switches 27, 28 and 33 for operation instruction, and also to the dip switches 41 for various settings provided on the substrate of the control device 36. There is. In this DIP switch 41, the second switch is set to enable / disable the refrigerant leakage detection function, which will be described later, and the first switch is set to the cool operation time, which will be described later. Further, the output of the microcomputer 37 includes the compressors 8 and 8 of the refrigerant circuits C1 and C2 and the DC fan motor 1
4, display unit 26, LEDs 29, 31, 32, 43, 4
4 is connected, and devices (rectifier circuit, charging circuit, etc.) that control charging of the battery (not shown) are also connected.

The microcomputer 37 operates by using the AC power supply when the AC power supply is connected and the battery when the AC power supply is disconnected. Similarly to the microcomputer 37, the DC fan motor 14 also operates with the AC power source as a power source via the rectifier circuit when the AC power source is connected, and operates with the battery as the power source when the AC power source is cut off. That is, during the cold storage operation in which the cold storage agent 6 is frozen, the DC fan motor 14 uses the output of the rectifier circuit as a power source and does not use the battery.

Next, the operation of the cold storage R will be described with reference to the flow chart showing the program of the microcomputer 37 in FIG. Now, the gas leak sensor 19 is connected to the microcomputer 37, and the dip switch 4
In 1, it is assumed that the refrigerant leakage detection function is set to be valid.

In the delivery base, when the low temperature storage R is connected to the AC power supply (AC200V) in step S1 and the microcomputer 37 is first powered on, charging of the battery is started and the microcomputer 3 is started.
In step S2, the setting operation state of each switch provided on the operation panel 24 is read (initial setting).

Here, provided on the operation panel 24 are a refrigerator switch 33 for instructing the start of cooling in the refrigerator, the refrigerating temperature selecting switch 27 for selecting and instructing the refrigerator temperature to + 5 ° C. which is the refrigerating temperature, and the freezing temperature. Refrigeration temperature selection switch 28 and LED 29 to select -18 ° C.
The ED 32 and the display unit 26, and when any of the switches 27 and 28 is operated, the LEDs 43 and 44 corresponding to the operation-selected temperature are turned on by the microcomputer 37.

After the freezing completion flag and each timer are cleared in step S3, the cold storage operation is started in step S4. In this cold storage operation, the microcomputer 37, based on the output of the cold storage sensor 17, both refrigerant circuits C1 and C2.
Operate the compressors 8 of 8 and coolers 10A ... 10B.
The cool storage agent 6 is cooled by.

Next, in step S5, it is determined whether or not the alternating current (AC) power source is energized. If it is connected and energized, the process proceeds to step S6 to determine whether the freezing completion condition of the cold storage agent 6 is satisfied. To determine. The freezing completion condition of the cold storage agent 6 is composed of two freezing end conditions and a battery charging completion condition. One of the freezing end conditions is that the temperature of the cold storage agent 6 based on the output of the cold storage sensor 17 is frozen or thawed. The temperature is, for example, 4 ° C. lower than −25 ° C., which is −29 ° C. or lower for more than 9 hours, and another is that the temperature of the cold storage agent 6 is −32 ° C. or lower, which is 7 ° C. lower than −25 ° C. It means that a certain state continued for 10 minutes or more.

Further, the microcomputer 37 detects the charge state of the battery based on the output of the battery sensor 39 and judges whether the charge is completed. If any one of the battery charging completion condition and the freezing ending condition is satisfied, the microcomputer 37 considers that the freezing of the cold storage agent 6 is completed, but if not, the freezing LED 29
Is turned on and the process proceeds to step S15. If the temperature of the cold storage agent 6 rises due to the door 3 being opened for a long time before the AC power source is connected in step S8, which will be described later, and the freezing completion condition is no longer satisfied, the microcomputer 3
7 determines that the freezing has been released, lights the freezing LED 29, and proceeds from step S6 to step S15 to restart freezing.

In step 15, it is determined whether the refrigerator switch 33 has been pressed, and if not, step S4.
If it is pressed, the process proceeds to step S16 and DC
The fan motor 14 is operated to circulate cool air in the storage chamber 2 to freeze the cold storage agent 6 and cool the storage chamber 2. The set temperature in this case is the temperature selected by the switches 27 and 28. In addition, the microcomputer 37
Turns on the LED 32 during the interior cooling.

When the freezing completion condition is satisfied in step S6 by the above operation, the microcomputer 3
In step S7, the freezing completion LED 31 is turned on.
From 6 to step S7, the DC fan motor 14 is operated, and based on the internal sensor 18, the internal cooling operation of maintaining the temperature of the storage chamber 2 at the set temperature is performed.

After the cold storage operation and the cold storage operation as described above, or in the middle thereof, articles such as food are stored in the storage chamber 2 of the low temperature storage R, disconnected from the AC power source, and loaded on the delivery vehicle. It When the AC power is no longer supplied to the low temperature storage R, the process proceeds from step S8 to step S9 to enter the cold insulation operation of cooling the storage chamber 2 by the latent heat of fusion of the cold storage agent 6.

During the cooling operation, the microcomputer 37 and the DC fan motor 14 are supplied with power by discharging the battery as described above. Further, the DC fan motor 14 is controlled by the microcomputer 37, and is operated when the temperature of the storage chamber 2 by the internal sensor 18 rises to the set temperature + 1 ° C., and is stopped when the temperature drops to the set temperature. As a result, the inside of the storage chamber 2 is maintained around the set temperature.

Next, in step S11, the microcomputer 37 determines whether or not 5 hours have elapsed from the start of the cold insulation operation. If 5 hours have elapsed, the microcomputer 37 proceeds to step S12 and sets D
The operation of the C fan motor 14 is stopped. Further, in step S13, it is determined whether or not the AC power supply is reconnected, and if it is connected, the process returns to step S3.
It progresses to 14 and it is judged whether 72 hours have passed since the cold insulation operation start. When 72 hours have passed, the operation of the microcomputer 37 itself is stopped.

That is, the cold insulation operation ends 5 hours after the AC power supply is cut off, and the DC fan motor 14 also stops thereafter.
All stops. The five hours are calculated as sufficient time required for delivery by the delivery vehicle. And 72
If the AC power supply is not connected within the time, the operation of the microcomputer 37 itself is stopped.

The cooling operation time by the microcomputer 37 is switched to, for example, 5 hours and 7 hours, 3 hours and 5 hours, or 5 hours and 10 hours by setting the dip switch 41 as described above. It can be changed. This makes it possible to easily deal with a change in the battery capacity.

Next, the refrigerant leak (hereinafter referred to as gas leak) detection operation by the microcomputer 37 will be described with reference to the flow charts of FIGS. 8 and 9 and the timing chart of FIG.

As described above, the gas leak sensor 19 is connected to the microcomputer 37, and if the dip switch 41 has the refrigerant leak detection function enabled, the microcomputer 37 issues a gas leak alarm in step S17 of FIG. Is issued, and if it is not here, it proceeds to step S18 and determines whether or not the gas leak condition is satisfied. The gas leak condition is shown in FIG. That is, the microcomputer 37 uses the cold storage sensor 17 and the gas leak sensor 1
Based on the output of 9, the temperature TS1 of the cold storage agent 6 cooled by the cooler 10A of the refrigerant circuit C1 (cooling temperature by the cooler 10A of the refrigerant circuit C1) and the cooler 10B of the refrigerant circuit C2. Temperature TS of regenerator 6 cooled by
2 (cooling temperature by the cooler 10B of the refrigerant circuit CS)
Is constantly monitored, and it is determined in step S27 of FIG. 9 whether the absolute value of the difference between the temperatures TS1 and TS2 is greater than the temperature T1 such as 20 ° C., for example.

Here, when the refrigerant does not leak from both the refrigerant circuits C1 and C2 and both are normally performing the cooling action, the difference between the temperatures TS1 and TS2 does not reach such a large value. , The microcomputer 37 performs step S2
It progresses from 7 to step S28. At step S28, either one of the temperatures TS1 and TS2 is higher than the temperature T3 such as -29 ° C (hence the other is -29 ° C or less), and the absolute value of the difference between the temperatures TS1 and TS2 is, for example, 9 ° C. It is determined whether the temperature is higher than the temperature T2.

When the cold storage agent 6 is sufficiently cooled (frozen) and the refrigerant does not leak from both the refrigerant circuits C1 and C2 and both of them normally perform the cooling action, the temperature TS1 is reached. And the difference between TS2 does not reach such a small value,
The microcomputer 37 returns from step S28 to step S27.

Here, for example, when a gas leak occurs in the refrigerant circuit C1 from the beginning of the cold storage operation, the temperature of the cooler 10A does not decrease, but only the cooler 10B decreases, so that the temperatures TS1 and TS2. The absolute value of the difference between
Immediately, it becomes larger than T1. Then, the microcomputer 37 proceeds from step S27 to step S29 and determines that a gas leak has occurred in the refrigerant circuit C1.

Further, in the state where the regenerator 6 is sufficiently cooled (frozen) as described above, for example, when a refrigerant leaks from the refrigerant circuit C1, the temperature difference between the both coolers 10A and 10B is gradually widened. Although there is no temperature T relatively early
The absolute value of the difference between S1 and TS2 is larger than T2. Then, the microcomputer 37 proceeds to step S28.
From step S29, it is determined that a gas leak has occurred in the refrigerant circuit C1 (YES in FIG. 10).

When the microcomputer 37 determines in step S29 that a gas leak has occurred, the process advances from step S18 to step S19 in FIG. 8 and the gas leak alarm delay timer (for example, 10) provided as its own function.
Minutes) to determine if the delay time has passed. If it has not elapsed, the process returns to step S18 and is repeated. When the gas leak condition is not satisfied within 10 minutes, the microcomputer 37 cancels the determination as shown on the left side of FIG. Therefore, it is possible to prevent false alarm issuance due to the influence of the external environment.

Next, when the gas leak condition is satisfied for 10 minutes, the microcomputer 37 proceeds from step S19 to step S19 to step S20 to determine the gas leaking refrigerant circuit. In this case, the refrigerant circuit C1 is used. Therefore, the process proceeds to step S21, and the compressor 8 of the refrigerant circuit C1 is stopped. The compressor 8 of the normal refrigerant circuit C2 continues to operate, and the freezing of the regenerator agent 6 and the cooling of the storage chamber 2 continue (in the case where the gas leaked refrigerant circuit is C2, the operation proceeds to step S22 and the refrigerant circuit C2 The compressor 8 of the refrigerant circuit C1 is stopped and the operation of the compressor 8 of the refrigerant circuit C1 is continued). Then, in step S23, a predetermined gas leak alarm is displayed on the display unit 26 and a warning is issued.

Next, the microcomputer 37 returns to step S17, and this time from step S17 to step S17.
In step 24, it is determined whether or not the gas leak alarm timer (10 hours) as a function of itself and the compressor stop time have elapsed. If the time has not passed, step S
Return to 17 and repeat this. Then, when 10 hours have passed, the microcomputer 37 proceeds from step S24 to step S25 to cancel the gas leak alarm in the display unit 26, restarts the operation of the compressor 8 of the refrigerant circuit C1 in step S26, and the microcomputer 37 37 resumes normal operation (including gas leak determination operation). Therefore, if the gas leak condition is satisfied again, the microcomputer 37 will execute the gas leak warning operation again.

For example, when only a single refrigerant circuit is installed in the cold storage R, the dip switch 41 disables the refrigerant leakage detection function, so that the microcomputer 37 is shown in FIGS. 8 and 9. Stop the refrigerant leak detection operation such as the alarm. Therefore, it is not necessary to connect the gas leak sensor 19 as a matter of course.

Further, the microcomputer 37 always executes a normal display on the display unit 26 for displaying the internal temperature, the set temperature and the like. Further, the microcomputer 37 monitors whether or not any abnormality (failure) has occurred in each of the sensors 17, 18, 19 (when the refrigerant leakage detection operation is set to be valid), 38, 39 by the data. ,
As described above, when the refrigerant leak detection function is disabled by the dip switch 41, the gas leak sensor 1
The abnormality detection operation for 9 is stopped.

Next, the microcomputer 37 shown in FIG.
The display control of the display unit 26 by the microcomputer 37 will be described with reference to the program flowchart of FIG. The microcomputer 37 determines in step S30 whether the refrigerating temperature selecting switch 27 and the freezing temperature selecting switch 28 of the operation panel 24 are simultaneously pressed,
If not, the process proceeds to step S56 and the above-described normal display is performed on the display unit 26.

If the refrigerating temperature selecting switch 27 and the freezing temperature selecting switch 28 are simultaneously pressed for 2 seconds or more, the microcomputer 37 proceeds to step S31 to display E1 on the display unit 26 and shifts to the check mode. To inform the user. Next, in step S32, it is determined whether either the refrigerating temperature selection switch 27 or the freezing temperature selection switch 28 has been pressed. If so, the process proceeds to step S56 to return to the normal display,
If it has not been pressed, the process proceeds to step S33, and it is determined whether the refrigerator switch 33 has been pressed.

If the refrigerator switch 33 is pressed while E1 is being displayed on the display unit 26, the microcomputer 37 proceeds to step S34 and the battery sensor 3
D0 which is the check code of 9 is first displayed for 2 seconds on the display unit 26.
After that, the data regarding the battery sensor 39 is displayed. Thus, when the battery sensor 39 is abnormal, it can be confirmed from the value.

Next, the microcomputer 37 determines in step S35 whether one of the refrigerating temperature selecting switch 27 and the freezing temperature selecting switch 28 is pressed, and if so, the process proceeds to step S56 to return to the normal display. At the same time, if it has not been pressed, the routine proceeds to step S36, where it is determined whether or not the refrigerator switch 33 has been pressed.

As described above, the battery sensor 3 is displayed on the display unit 26.
When the refrigerator switch 33 is pressed while displaying the data regarding 9, the microcomputer 37 proceeds to step S37 and displays the check code d1 of the filter sensor 38 on the display unit 26 for the first 2 seconds. , Data about the filter sensor 38 is displayed. Thus, if the filter sensor 38 is abnormal, the value can be confirmed.

Next, the microcomputer 37 determines in step S38 whether one of the refrigerating temperature selecting switch 27 and the freezing temperature selecting switch 28 has been pressed. If so, the process proceeds to step S56 to return to the normal display. At the same time, if it has not been pressed, the process proceeds to step S39 to determine whether the refrigerator switch 33 has been pressed.

As described above, the filter sensor 3 is displayed on the display unit 26.
When the refrigerator switch 33 is pressed while displaying the data related to 8, the microcomputer 37 proceeds to step S40 and displays the check code d2 of the in-compartment sensor 18 on the display unit 26 for the first 2 seconds. After that, the data regarding the internal sensor 18 is displayed. In this way, when an abnormality occurs in the in-compartment sensor 18, the value can be confirmed.

Next, the microcomputer 37 determines in step S41 whether one of the refrigerating temperature selection switch 27 and the freezing temperature selection switch 28 has been pressed. If so, the process proceeds to step S56 to return to the normal display. At the same time, if not pressed, the process proceeds to step S42 to determine whether or not the refrigerator switch 33 is pressed.

As described above, the refrigerator switch 33 is operated while the data relating to the internal sensor 18 is being displayed on the display unit 26.
When is pressed, the microcomputer 37 proceeds to step S43 to display the check code d3 of the cold storage sensor 17 for the first 2 seconds on the display unit 26, and then displays the data relating to the cold storage sensor 17. Thus, when the cold storage sensor 17 has an abnormality, it can be confirmed from the value.

Next, the microcomputer 37 determines in step S44 whether one of the refrigerating temperature selecting switch 27 and the freezing temperature selecting switch 28 is pressed, and if so, the process proceeds to step S56 to return to the normal display. At the same time, if it has not been pressed, the routine proceeds to step S45, where it is determined whether or not the refrigerator switch 33 has been pressed.

As described above, the refrigerator switch 33 is operated while the data relating to the cold storage sensor 17 is displayed on the display unit 26.
If is pressed, the microcomputer 37 proceeds to step S46 and uses the dip switch 41 to
It is determined whether or not the above-mentioned refrigerant leakage detection function is enabled.

If the setting is enabled, the microcomputer 37 proceeds to step S47 to display the check code d4 of the gas leak sensor 19 for the first 2 seconds on the display unit 26, and then displays the data relating to the gas leak sensor 19. . As a result, the gas leak sensor 19
If there is an abnormality, it can be confirmed from the value.

On the other hand, when the DIP switch 41 is set to be invalid, the microcomputer 37 proceeds from step S46 to step S50. Therefore, the above-mentioned data display regarding the gas leak sensor 19 is not performed.

When the refrigerant leakage detection function is enabled, the microcomputer 37 next determines in step S48 whether one of the refrigerating temperature selection switch 27 and the freezing temperature selection switch 28 has been pressed, and it is pressed. If so, the process proceeds to step S56 to return to the normal display, and if not pressed, the process proceeds to step S49 to determine whether the refrigerator switch 33 has been pressed.

When the refrigerator switch 33 is pressed while the data concerning the gas leak sensor 19 is being displayed on the display unit 26 as described above, the microcomputer 37 is used.
Advances to step S50 to display the check code E3 of the dip switch 41 on the display unit 26. next,
The microcomputer 37 determines in step S51 whether one of the refrigerating temperature selection switch 27 and the freezing temperature selection switch 28 has been pressed, and if so, the step S51.
If the button is not pressed, the process proceeds to step S52 and the refrigerator switch 3
It is determined whether or not 3 is pressed.

As described above, when the refrigerator switch 33 is pressed with the display unit 26 displaying E3,
The microcomputer 37 proceeds to step S53 to display the setting state of the dip switch 41 on the display unit 26. In this case, the microcomputer 37 displays the setting state of the four switches (1 to 4) of the DIP switch 41 in hexadecimal.

Next, in step S54, the microcomputer 37 determines whether one of the refrigerating temperature selection switch 27 and the freezing temperature selection switch 28 is pressed, and if so, the process proceeds to step S56 to return to the normal display. At the same time, if it has not been pushed, the routine proceeds to step S55, where it is determined whether or not the refrigerator switch 33 has been pushed. If it is pressed, the process proceeds to step S56 to return to the normal display.

Each value such as the temperature shown in the embodiment can be variously changed according to the capacity and capacity of the low temperature chamber. Also,
In the embodiment, the two-system refrigerant circuit has been described, but the present invention is also effective for a low temperature warehouse having more refrigerant circuits.

[0063]

As described in detail above, according to the invention of claim 1, in a low temperature warehouse provided with a refrigerant circuit, there is provided a control device to which a sensor for detecting refrigerant leakage from the refrigerant circuit can be connected. This control device has a setting switch for setting the refrigerant leakage detection function, and when the function is set to be invalid by this setting switch, along with stopping the refrigerant leakage detection operation from the refrigerant circuit, When the refrigerant leak detection function is enabled by the setting switch,
Since the refrigerant leakage detection operation is executed when the sensor is connected, it is easy to enable / disable the refrigerant leakage detection function with the setting switch according to various characteristics such as the number of refrigerant circuits in the low temperature warehouse. It becomes possible to set to, and the operability is remarkably improved.

According to the invention of claim 2, in addition to the above, the control device has a function of detecting an abnormality of the sensor connected to the control device, and the refrigerant leakage detection function is effectively set by the setting switch. If it is, the abnormality detection operation of the sensor for detecting the refrigerant leakage is performed, and if the function is set to be disabled, the abnormality detection operation of the sensor is stopped. It is possible to automatically set the sensor abnormality detection operation of the control device to a state adapted to the validity / invalidity of the refrigerant leakage detection function. Therefore, the operability is further improved.

According to the invention of claim 3, in addition to the above, the control device is provided with a display device, and in the case where the refrigerant leakage detection function is effectively set by the setting switch, in order to detect the refrigerant leakage in the display device. When the function is disabled, the data display related to the sensor is prohibited.Therefore, the data display based on the sensor abnormality detection operation of the control device is displayed by the setting switch. Effectiveness of refrigerant leakage detection function /
It is possible to automatically set a state that is suitable for invalidation.
Therefore, the operability is further improved, and it is possible to prevent the occurrence of erroneous recognition by the user.

According to the invention of claim 4, in addition to the above, an operation panel provided with a plurality of switches for instructing the operation of the control device and a display device is provided, and the control device comprises:
Since the normal display is always executed on the display device and the check mode for displaying the data related to the sensor is displayed instead of the normal display on the display device based on the operation of the switch, without disassembling the exterior parts. By operating the switch on the operation panel, the state of the sensor can be extremely easily inspected.

According to the fifth aspect of the present invention, in addition to the above, the control device shifts to the check mode when two or more switches are simultaneously operated. Therefore, a special inspection switch is provided. Since it is not necessary to provide it, it is possible to reduce the number of parts and costs, and since it is an operation that cannot be normally considered, it is possible to prevent the occurrence of an erroneous operation.

[Brief description of drawings]

FIG. 1 is a perspective view of a cold storage according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional side view of a cold storage.

FIG. 3 is an overhead view of the lower part of the low temperature refrigerator with the door opened.

FIG. 4 is a refrigerant circuit diagram of a low temperature chamber.

FIG. 5 is a front view of an operation panel of a cold storage.

FIG. 6 is a front view of a control device for a cold storage.

FIG. 7 is a flowchart showing a main program of a microcomputer.

FIG. 8 is a flowchart showing a gas leak detection program of a microcomputer.

FIG. 9 is a flow chart showing a gas leak detection program of the same microcomputer.

FIG. 10 is a timing chart illustrating a gas leak detection operation of the microcomputer.

FIG. 11 is a flowchart showing a display control program of a microcomputer.

[Explanation of symbols]

C1 refrigerant circuit C2 refrigerant circuit R cold storage 8 compressor 10A, 10B cooler 17 Cold storage sensor 19 Gas leak sensor 24 Operation panel 26 Display 27 Refrigeration temperature selection switch 28 Freezing temperature selection switch 33 refrigerator switch 36 Controller 37 Microcomputer 41 DIP switch

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-126061 (JP, A) JP-A-3-70962 (JP, A) JP-A-3-91675 (JP, A) JP-A-3- 213972 (JP, A) JP 5-126421 (JP, A) JP 6-2915 (JP, A) JP 63-96466 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F25B 49/02 520 F25D 11/00 101 F25D 23/00 301 F25D 29/00 F25B 49/02 570 F25B 49/02

Claims (5)

(57) [Claims] 1. A low-temperature warehouse equipped with a refrigerant circuit, comprising a control device to which a sensor for detecting refrigerant leakage from the refrigerant circuit is connectable, the control device comprising:
It has a setting switch for setting the refrigerant leakage detection function, and when the function is disabled by this setting switch, the refrigerant leakage detection operation from the refrigerant circuit is stopped and the refrigerant leakage detection is performed by the setting switch. When the function is set to be valid, the refrigerant leak detection operation is executed in a state in which the sensor is connected. 2. The control device has a function of detecting an abnormality of a sensor connected to the control device, and when the refrigerant leakage detection function is effectively set by a setting switch, a sensor for detecting refrigerant leakage. 2. The abnormality detection operation of the sensor is executed, and the abnormality detection operation of the sensor is stopped when the function is disabled.
Low temperature warehouse. 3. The control device is provided with a display device, and when the refrigerant leakage detection function is set to be valid by a setting switch, the control device executes data display regarding a sensor for detecting refrigerant leakage in the display device and the function. 3. The low temperature warehouse according to claim 2, wherein the display of data relating to the sensor is prohibited when is set to be invalid. 4. An operation panel provided with a plurality of switches for instructing the operation of the control device and a display device, wherein the control device always performs normal display on the display device and 4. The low temperature warehouse according to claim 3, wherein, based on an operation, a check mode for displaying data relating to a sensor is displayed instead of the normal display on the display device. 5. The cold storage according to claim 4, wherein the control device shifts to the check mode when two or more switches are simultaneously operated.