JPH0461272B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of operating a refrigerator equipped with a cooling heat exchanger, and more particularly to a method of operating a refrigerator for use in a case.

In addition to the usual electric motors for blowing air and boilers for hot water supply, electric equipment also includes refrigerators for refrigerators, refrigerators, air conditioning equipment, etc., and has power receiving equipment that allows multiple units of these electrical equipment to operate in parallel. As an example, there is a large store 1 such as a supermarket or a department store as shown in FIG. This power receiving equipment connects the case refrigerator R ₁ ,
Electrical equipment such as R ₂ ...R _K , R _K+1 ...Rn _-1 , Rn, an air conditioning refrigerator 3, a refrigerator 4 for cold storage, lighting equipment 5, and a blower (not shown) are in operation. Also, one compressor C ₁ like R ₁ is installed in the case refrigerator.
A refrigeration cycle is configured with a condenser 6 and a liquid receiver 7 to cool three product storage sections L ₁ , L _{2 , and L 3 ,} and one compressor C ₂ and two Connecting the product storage parts L ₄ and L ₅ of the stand, like R ₃ ,
A refrigeration cycle configured such that three product compartments L ₆ , L ₇ , L ₈ are cooled by two compressors C ₃ and C ₃ ' connected in parallel, such as Rn _-1 and Rn. to 1
1 compressor Cn _-1 , 1 product storage Lm _-1 with Cn,
There are various types of refrigerators, such as those with a refrigeration cycle configured to cool The refrigerating and air conditioning equipment is equipped with a refrigerator and a condenser so that the load space associated with each refrigerator is cooled by the cold air that has passed through the cooling heat exchanger. In addition, V ₁ , S ₁ , V ₂ , S ₂ ...Vm, Sm
...S', S'' are refrigerant liquid control solenoid valves (hereinafter referred to as liquid solenoid valves) installed one by one corresponding to the load space related to the refrigerator, such as each product storage area L ₁ , L ₂ ..., etc.
and a temperature sensor for the product storage section, and each liquid solenoid valve is activated individually when the temperature of the product storage section reaches the set temperature, so that the load space is independent from the related refrigerator and other load spaces. actuates to close the valve.

For example, when the temperature of product storage section L ₁ reaches the set temperature, only liquid solenoid valve V ₁ is closed, and liquid refrigerant is supplied to the cooling heat exchangers of product storage sections L ₂ and L ₃ that have not reached the set temperature. The supplied liquid solenoid valves V ₂ and V ₃ remain open, and the compressor C ₁ to which this product storage section L ₁ is associated continues to operate without any direct relationship with the closing of the liquid solenoid valve V ₁ . do.

Therefore, the electric power required to operate such refrigeration and air conditioning equipment depends on the load conditions of each refrigerator, for example,
This varies greatly depending on the amount of product stored, rotation rate, number of customers, outside air conditions, and frost formation.If each refrigerator is left to operate freely, the capacity of the power receiving equipment cannot be adjusted at the expected moment. It is necessary to set it according to the maximum power usage. Furthermore, if a control device capable of rationally reducing the power consumption of electrical equipment operated simultaneously can be obtained, the running costs of power receiving equipment and the electrical energy consumption can be greatly reduced.

The object of the present invention is to reduce the number of times a cooling heat exchanger must be defrosted, and to save electricity by using a show case refrigerator that is operated throughout the year in a large store such as a supermarket.

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a block configuration diagram showing an embodiment in which the control device of the present invention is applied to the large-scale store equipment shown in FIG. It is represented by the number.

_{X 1 , X 2 ... _ _} ...Pn is a centralized controller 8 and relays X ₁ , X ₂ by a microcomputer system configured by a large-scale integrated circuit.
A connector 9 connects the temperature sensors S ₁ , S ₂ ...Sn of each product storage section to the voltage frequency converter 10, which sequentially switches the temperature input from the temperature sensors S 1 , S 2 ...Sn according to instructions from the central controller 8. A multiplexer that sends power to an input/output interface 12 via a counter 11, 13 a relay for power supply to a timer load 14 such as a lighting equipment 5 or a boiler (not shown) that needs to start or stop power supply at a fixed time, and 15 a warning display device. , 16
is an alarm notification device, Q is a control setting value input device, 1
7 is a time display device, 18 is a power consumption recording device, 1
9 is a storage device for storing control settings and programs (hereinafter referred to as ROM); 20 is a storage device for program control execution (hereinafter referred to as RAM); 22 is a converter for detecting the power usage of the power receiving equipment; 23 is a power usage display It is a vessel.

The large-scale integrated circuit 24 constituting the central controller 8 includes a load management logic 25, a temperature management logic 26, a time management logic 27 that divides the frequency of the commercial frequency power supply and manages time, and a system controller (not shown). (omitted), and is connected to the ROM 19, RAM 20, and input/output interface 12 via an address bus 28, data buses 29, 29, and input/output ports 30.

The control setting value input device Q includes, for example, a control temperature setting Q ₂ for each freezing and refrigeration equipment, a power consumption control switching time setting Q ₃ (to be described later), a stop time setting Q ₄ , and a maximum allowable power setting Q _{5 .} , power differential setting Q ₆ , night setback setting Q ₇ , timer load management time setting Q ₈ , etc. Setting values and refrigerator or product compartment numbers can be determined using the numeric keypad or rotary switch. The value is converted into a digital quantity and sent to the input/output interface. The alarm display device 15 is a light emitting diode, etc.
Displayed by suitable light emitting elements F ₁ , F ₂ ...Fl,
The display contents may include, for example, an excessive power usage warning.
F ₁ , Load display during additional time control F ₂ ... Temperature abnormality alarm in load space such as product storage section Fl- ₂ ... Power outage alarm Fl _-1 ,
There are self-check function failure alarms Fl, etc. Output signals of the temperature abnormality alarm Fl _-2 , power outage alarm Fl _-1 , and self-check function failure alarm Fl are sent to the security company and security station via the OR logic element 31. etc. is connected to the alarm notification device.

Control of the power receiving equipment having such a configuration will be described below.

In order to simplify the explanation of the present invention, in the refrigerator in FIG. 1 and FIG. 2 related to the explanation thereof, the compressors C ₁ , C ₂ ...Cn _-1 , Cn are connected to the relays X ₁ , X ₂ ...Xn _{- 1} ,
Each compressor is connected to a load space L ₁ when powered through Xn,
L ₂ ...L', L'', Lm _-1 , Lm are operated individually according to the cooling state, and when frost forms on the heat exchanger that cools each load space, the operation is controlled in relation to other refrigerators. Rather, the refrigerator is shown as having a controller (not shown) that can independently perform forced defrosting operation using a hot gas or electric heater, which is a publicly known means.Therefore, the central controller 8 in the figure The relationship between the refrigerators R ₁ , R ₂ . . . Rn, 3, 4 is that defrost detectors D ₁ , D _{2 .} . . and connectors P ₁ ,
Also, through P ₂ ..., load spaces L ₁ , L ₂ ...Lm, L′,
The temperature of L'' is detected via temperature detectors S ₁ , S ₂ ...Sm, S', S'', multiplexer 9, etc., and these detection inputs and various setting values written in advance in the storage device 19 and While taking into account the total power consumption of the power receiving equipment, the central controller 8 controls the opening and closing of _the relays X ₁ , X ₂ ... It is designed to control the liquid solenoid valves V ₁ , V ₂ ...Vm _-1 , and Vm for management.

Therefore, in order to control the power receiving equipment by the central controller 8, in advance, so that one or more of the electrical devices constituting the power receiving equipment is always in a stopped state,
According to the program written in ROM19,
Relay X ₁ , X ₂ ...Xn _-1 , Xn, any one of 13
The total power consumption (hereinafter referred to as "total power amount") is achieved by sequentially opening three or more electrical devices and forcibly stopping all electrical devices for a set time at regular intervals.
When the total power consumption in the power receiving equipment (hereinafter referred to as power consumption) exceeds a set value, the electric equipment is stopped in accordance with the predetermined order written in the ROM 19, and the consumption is reduced. It is combined with a power consumption control mechanism that suppresses power consumption below a set value.

However, if the electrical equipment whose operation is stopped by the output signal from the power consumption control mechanism or the total power consumption control mechanism is a refrigerator, the room or product that is maintained at a low temperature by the refrigerator The chiller is stopped after confirming that the load space such as the storage room is under the temperature conditions specific to that space.The operating relationship is as shown in Figure 3, and when the chiller is stopped, Off-cycle defrosting of the cooling heat exchanger is performed.

That is, the power consumption setting value of the power receiving equipment is input from the control setting value input device Q to the ROM 19 of the central controller.
W _S Power differential W _D to be described later, cooling temperature T ₁ , T ₂ ...Tm _-1 , Tm of each load space, switching time τ ₁ , τ ₂ of total power amount control, similarly, stop time τ′ ₁ ，
In the state in which τ′ ₂ is written, when the load of the refrigerator that constitutes the power receiving equipment is in a normal state and the power consumption is less than the set value W _S , the output signal from the total power consumption control mechanism is constant. It is output every time τ ₁ , τ ₂ , and for example, the time interval τ is set for each of the first group of electric devices C _K C _K-1 ... and the second group of electric devices Cn, Cn _-1 ... one by one. An output signal is output to open the corresponding relays X _K , X _{K - 1 .} . .

As shown above, relays X _K , X _K-1 …Xn, Xn _-1 …
is sequentially opened, and the electrical equipment of the first and second group compressors is sequentially stopped, so that when the ambient temperature is higher than 0°C, cooling heat exchange corresponding to each compressor is performed during the operation stop time. Off-cycle defrosting is performed sequentially depending on the atmosphere of the container.

In this case, at point (G) when the power consumption exceeds the allowable value W _S due to an increase in the refrigeration load, etc., the power consumption control mechanism is activated for a certain period of time τ (this time width is the total power consumption control mechanism time). width τ (preferably shorter than ₀ ), an output signal is issued and the corresponding relays Xn, Xn - are activated to stop the second group of electrical devices Cn, Cn _{-1 . 1} ...is released.

The classification of electrical equipment into Group 1 and Group 2 is for convenience only, and when grouping is not necessary,
Treated as C _K = Cn.

Through such power consumption control, the power consumption is reduced by an amount equal to or greater than the power differential W _D to the set value W _S
When the power consumption decreases further, an output signal is issued to increase the number of operating electrical devices Cn, Cn _-1 , Cn _-2 , etc. that are subject to power consumption control, so that they return to operation in the reverse order from when they stopped. .

When going through this process of power consumption control,
If the load condition returns to light load _H1 or normal load _H2 , power consumption control is no longer necessary, and only total power amount control continues.

As described above, in the power supply control device of the present invention, the power consumption of the power receiving equipment is kept below the rated power of the power receiving equipment through total power control, and the power consumption cannot be kept below the set value with such total power amount control alone. Under conditions where this cannot be maintained, power consumption control may be used to forcibly switch off electrical equipment with warm temperature control or lighting conditions.
Operation is stopped and power consumption is managed to never exceed the rated power of the power receiving equipment.

Therefore, such power consumption control and total power consumption control are performed on the refrigerator included in the electrical equipment, and more specifically, on the refrigerator included in the electrical equipment.
This is done on the premise that the products in the load space, which are maintained at low temperatures by each refrigerator, will not be damaged, and inside the large-scale integrated circuit 24, the total power amount control and power consumption control are An output signal is output through a sequence as shown in FIG. 4, which takes into consideration the temperature conditions of the load space to which the refrigerator relates and the defrosting conditions. In this case, the parts K ₁ , K ₂ ,
As seen in K ₃ , there are cases where no output signal is actually output.

That is, in FIG. 4, 15
is a display light emitting diode, 16 is a power alarm, 18
19′ is a power system storage unit of ROM, 19″ is a storage unit for total power consumption control,
22 is a detection converter for input from the power sensor 22';
23 is the power usage display section, 26 is the temperature management logic, 32 is the AND logic, 33 is the OR logic,
Q ₄ is for stop time setting, Q ₅ is for maximum allowable power setting,
Q ₆ is an input device for power differential setting,
X' indicates a drive unit for relay
E ₁ is the total power consumption control mechanism, E ₂ is the power consumption control mechanism,
E ₃ indicates a defrost signal, E ₄ indicates a temperature signal, and under such a sequence, if an output signal is now output from the total power consumption control mechanism E ₁ to a certain electrical device at fixed time intervals. , when the temperature output signal _E4 is not output after a certain period of time has elapsed after the temperature of the load space related to this electrical equipment falls below the set temperature according to the control sequence written in the ROM 19 in advance. In addition, if this electrical equipment is not related to defrosting, or if it is related but not defrosted, an output signal that is a forced stop permission signal is output from the temperature control logic 26, so the OR logic 33
Received an output signal that is a forced stop permission signal from
AND logic 32 outputs an output signal and drives the drive unit.
By activating X', the display light emitting diode 15 indicates that the operation of the electrical equipment is stopped due to total power consumption control, and the relay X is turned off to stop the electrical equipment.
Stopping for the set time written in ROM19',
In other words, the system is forced to stop intermittently. Further, this operation is exactly the same for the output signal from the power consumption control mechanism _E2 .

That is, according to this sequence, if the electrical equipment to be controlled by the control mechanism is a refrigerator,
Defrost signal E ₃ and temperature signal E ₄ are not output,
When a forced stop permission signal is issued from the temperature management logic 26, the total electric energy control mechanism E ₁ is activated at regular intervals.
When a forced stop signal is output from
The matching signals from the OR logic 33 and the AND logic 32 are inputted, and the operation of the refrigerator is stopped for the previously set time. In addition, when the refrigerator is defrosting or has just been defrosted and the temperature of the product storage area, which is the load space, has just reached the set temperature, the defrost signal _E3 and the temperature signal are not activated. Since E ₄ does not enter the AND logic 32, even if the signals from the control mechanisms E ₁ and E ₂ are output via the OR logic 33,
AND logic 32 does not operate, and the intermittent operation stoppage of the refrigerator is avoided, and as a result, the compressor of the refrigerator does not enter total power consumption control until the next total power consumption control cycle, and , temperature control logic 2
Unless the condition is such that an output signal is output from 6, the compressor will not be stopped by power consumption control.

According to the above-mentioned operating method of the present invention, since the supply of liquid refrigerant to the cooling heat exchanger is forcibly stopped for a set time at regular intervals, the load on the refrigerator is reduced during this period. By combining forced defrosting and intermittent operation during cooling operation, off-cycle defrosting is performed when the supply of liquid refrigerant to the cooling heat exchanger is stopped. As a result, the rate of increase in frost that accumulates on the cooling heat exchanger over time during cooling operation becomes extremely small, making it possible to reduce the number of forced defrosts, and since the amount of frost accumulated during cooling operation is small, The cooling heat exchanger is operated at a high heat exchange rate and can exhibit sufficient cooling performance.

Furthermore, even if a preset time for stopping liquid refrigerant to the cooling heat exchanger comes during the cooling operation period immediately after forced defrosting between forced defrosts, this time is skipped. Since the liquid refrigerant is continuously supplied to the cooling heat exchanger, it is possible to prevent the temperature of the product storage section from rising immediately after forced defrosting.

[Brief explanation of the drawing]

The drawings show an embodiment of the method of operating a refrigerator according to the present invention, FIG. 1 is a configuration diagram of electrical equipment showing an example of power receiving equipment in a large-scale store, and FIG. FIG. 3 is a time chart showing an outline of control, and FIG. 4 is a block diagram showing an example of the load management logic of the block diagram shown in FIG. 2. R ₁ , R ₂ ... R _K , R _K+1 ... Rn _-1 , Rn ... Refrigerator for storage case, 3 ... Refrigerator for air conditioning, 4 ... Refrigerator for cold storage, 8 ... Central controller, L ₁ …Ln, L′,
L″...Load space, 25...Load management logic.

Claims (1)

[Claims] 1. In a refrigerator that has a cooling heat exchanger placed in the product storage area and cools the load space with cold air obtained by exchanging heat with the cooling heat exchanger during operation of the refrigerator, forced defrosting means is activated. In addition, during the cooling operation period between forced defrosts, the central controller Supply and stop of liquid refrigerant to the cooling heat exchanger are alternately repeated at preset intervals, and liquid refrigerant to the cooling heat exchanger is stopped at the beginning of cooling operation immediately after forced defrosting. A method of operating a refrigerator that continues to supply liquid refrigerant even when the time is up.