JPH01163584A - Method of operating refrigerator - Google Patents

Abstract

PURPOSE: To achieve a power conserving effect and a reduction in the frequency of defrosting of a heat exchanger for cooling, by alternately repeating the supply and stoppage of a liquid refrigerant to the heat exchanger for cooling during the cooling operation period between forced defrosting steps. CONSTITUTION: A large integrated circuit 24 forming a centralized controller 8 has a load managing logic 25, a temperature managing logic 26, a time managing logic 27 and a system controller built thereinto. In the control of power receiving equipment, a combination is made between a total electric energy control mechanism in which one or more of relays X1 , X2 ...Xn-1 , Xn and 13 are opened sequentially according to a program written into an ROM 19 to ensure the stoppage of one or more of electric appliances, and all of the electric appliances are forcibly stopped by a set time at a fixed time interval and a total power consumption control mechanism in which the electric appliances are stopped in the predetermined sequence, when a total power consumption exceeds a set value so that the power consumption is held below the set value. This reduces a load on a refrigerating machine to obtains a power conservation effect while minimizing the frequency of forcible defrosting.

Description

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

Electrical equipment includes not only regular lighting, blower motors, and hot water boilers, but also refrigerators such as freezer/refrigerator showcases, refrigerators, and air conditioning equipment. For example, large stores such as supermarkets and department stores as shown in Figure 1 (1)
There is. This power receiving equipment is connected to an appropriate power receiving device (2
), the showcase refrigerator (Rr) (Rs > - (RK) (RK + r >.
Electrical equipment such as (Rn-+) (Rn), an air conditioning refrigerator (3), a refrigerator for cold storage (4), a lighting equipment 5), and a blower (not shown) are in operation. In addition, for showcase refrigerators, one compressor (C8) can handle 3 as shown in (R1).
A refrigeration cycle is configured with a condenser (6) and a liquid receiver (7) to cool the product storage section (Ll) (t,, >(L3) of a single unit, such as <R3). Compressor (
C2) with two product storage units (t4) (L, ) connected, and (R3) with two compressors (C3) (C8') connected in parallel to store three products. Part (L6) (
L7) A refrigeration cycle configured to cool (t8), like (Rn-I) (Rn), one compressor (Cn-1>(Cn) and one product storage section ( Lr
There are various types of refrigeration systems, such as those with a refrigeration cycle configured to cool the air (l) (Lm), and the air-conditioning refrigerator (3) and refrigerated warehouse cooling machine (4) are not particularly shown. However, like the showcase refrigerator, it is equipped with a compressor and a condenser, and the load space related to each refrigerator is cooled by the cold air that has passed through the cooling heat exchanger. The equipment is configured.

In addition, (Vl) (St), (Vz) (St) - (Vm
) (Sm)"Is'BaS") is each product storage section (t, +)
(t, , each liquid solenoid valve is operated to close the valve individually when the temperature of the product storage section reaches a set temperature, independently of the refrigerator and other load spaces to which the load space is related. .

For example, when the temperature of the product storage section (L, ) reaches the set temperature, only the liquid solenoid valve (Vl> is closed, and the product storage section (1, 2) (L, ) that has not reached the set temperature is cooled. The liquid solenoid valve <vx) (vs) that supplies liquid refrigerant to the heat exchanger remains open, and the compressor (C1) to which this product storage section (L,) is associated is closed to the liquid tw, valve (■,). Operation continues without any direct relationship with the closure of the valve.

The power required to operate such refrigeration and air conditioning equipment varies greatly depending on the load conditions of each refrigerator, such as the amount of stored products, rotation rate, number of customers, outside air conditions, and frost formation. Therefore, when each refrigerator is left to operate freely, it is necessary to set the capacity of the power receiving equipment according to the expected maximum power usage at the moment. 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.

An object of the present invention is to reduce the number of times a cooling heat exchanger is defrosted in large-scale stores such as supermarkets by saving electricity by using a showcase refrigerator that is operated throughout the year.

The present invention will be described in detail below based on the drawings.

FIG. 2 is a block 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,>(X,)...(Xn) is the compressor (c+) (ci)...(Cn) that constitutes each electrical device or refrigerator
Relay that supplies and stops power to (P+) (P+')
, (Pg) (Pz') - (Pn) are integrated controllers <8> and relays (L) (L) - (Xn) by a microcomputer system constructed from large-scale integrated circuits.
), and (9) sequentially switches the temperature input from the temperature detectors (St>(St)...(Sn)) of each product storage section according to instructions from the central controller (8). A voltage frequency converter (10), a multiplexer that sends to the input/output interface (12) via a counter (11), (
13) is a timer load that only needs to start or stop power supply at a fixed time, such as lighting equipment (5) or boiler (not shown).14
), (15) is the alarm display device, (15) is the power supply relay for (
16) is an alarm notification device, (Q) is an input device for control setting values, (17) is a time display device, (18) is a power usage recording device, and (19) is a storage device for storing control settings values and programs. (hereinafter referred to as ROM), (20) a storage device for program control execution (hereinafter referred to as RAM), (22) a converter for detecting the power usage of the power receiving equipment, and (23) a power usage indicator.

Therefore, the large-scale integrated circuit (
24) has a built-in load management logic (25), temperature management logic (26), time management logic (27) that divides the frequency of the commercial frequency power supply and manages time, and a system controller (not shown). address bus (28
), data bus (29) (29) input/output boat (30)
It is connected to the ROM (19), RAM (20), and input/output interface (12) via.

The control setting value input device <Q) includes, for example, the setting of the control temperature of each freezing and refrigeration equipment (Q,), the setting of the switching time of power consumption control (Q3), which will be described later, and the setting of the stop time (Q4).
), maximum allowable power setting (Q, ), power differential setting (Q, ), night set pack setting (Q7), timer load management time setting (Q8), etc., and all of these settings are related to the setting value and the refrigerator or product. The storage unit number is sent to the input/output interface by converting the operation value of the numeric keypad or rotary switch into a digital quantity. Alarm display device (
15) is a suitable light emitting device (Fl) such as a light emitting device.
)(p*)...(Ff), and the display contents include, for example, excessive power usage alarm (F,), load display during additional time controlffx)...load of product storage, etc. Space temperature abnormality alarm (PIT)...Power outage alarm ffL
+), self-check function failure alarm (Fl2>, etc.), including temperature abnormality alarm (Ff-6) and power outage alarm (Fl2>).
12-, ), the output signal of the failure alarm (FN) of the self-check function is connected via an OR logic element (31) to an alarm notification device for a security company, security station, etc.

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

In order to simplify the explanation of the present invention, the refrigerator in FIG. 1 and FIG. 2 related to the explanation thereof is a compressor (C+>
(Ct)'...(Cn-I) (Cn) is the relay (x+
>(x, >-(xn-1)(Xn), each compressor is connected to the load space (L+)(Lal...
-)-(Lm-+) (Lm) is operated individually according to the cooling state of The refrigerator is shown as having a controller (not shown) that can perform forced defrosting operation using pot gas or an electric heater, which are known means. Therefore, the central controller (8) and the refrigerator (R1) (R2>-(Rn) (3) in the figure
The relationship with (4) is that the defrost detector (D
I) (Dri... and connector (P,) (P,)...
Also, the load space (L+) (L2) - (Lm
)(L')(L”) using a temperature sensor (S,>
(S,)...(Sm) (S')(S"), detected via multiplexer (9), etc., and these detection inputs and various setting values written in advance in storage device (19) The central controller (8) controls the power supply relay (XI) (
L)...(XI1-1>(Xn) and liquid solenoid valve (V+) for opening/closing the power supply relay (13) of the timer load and controlling the temperature of the load space (V,)...(Vm-I) (Vm).

Therefore, to control the power receiving equipment by the central controller (8),
In order to ensure that one or more of the electrical devices that make up the power receiving equipment are in a stopped state, the leaf one relay (L) (L) - ( Xn-+ )(Xn)(13
) by sequentially opening one or more of the following and forcibly stopping all electrical equipment for a set period of time at regular intervals to reduce the total power consumption (hereinafter referred to as "total power amount"). When the total power consumption (hereinafter referred to as power consumption) in the control mechanism and power receiving equipment exceeds the set value, the electrical equipment is stopped in accordance with the predetermined order written in the ROM (19) and the power consumption is reduced to the set value. It is combined with a power consumption control mechanism that suppresses the power consumption below.

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 temperature of the room or product storage room that can be maintained at a low temperature by the refrigerator will be affected. The load space is stopped after confirming that the temperature condition is unique to that space.The operating relationship is as shown in Figure 3.When the chiller is stopped, the cooling heat exchange Off-cycle defrosting of the equipment is performed.

That is, the power consumption setting value (w,) of the power receiving equipment is input from the control setting value input device Q into the ROM (19) of the central controller, the power differential (w9>, which will be described later), and the cooling temperature (L) (L) of each load space. −(Im−+)(Tm), total power consumption control switching time (τ, )(τ2), similarly, stop time (
In the state where τ′, )(τ′,) 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,), total power consumption control is performed. An output signal from the mechanism is output at fixed time intervals (τI) (τ,), and for example, the first group of electrical equipment (CK) (CK-+)
The corresponding relays (XK) (XK −+)−(
An open output signal of Xn) (Xn-+)... is output.

As shown above, relay (XK) (XK-1>・(Xn
) (Xn-1>-... are opened sequentially, and the first and second groups
By sequentially stopping the operation of the electrical equipment that is the compressor of the group, when the ambient temperature is higher than 0°C, off-cycle defrosting by the atmosphere of the cooling heat exchanger corresponding to each compressor is performed sequentially during the operation stop time. It is done.

In this case, when the power consumption exceeds the allowable value (w,) due to factors such as an increase in the refrigeration load (point G), the power consumption control mechanism The output signal is output every time the total electric power control mechanism has a time width τ (preferably shorter than
:n)(Cn-+)... in a predetermined order, the corresponding relays (Xn) (Xn
-I)... is released.

Note that the division of electrical equipment into the first group and the second group is for convenience, and when grouping is not necessary, they are treated as C,=Cn.

When power consumption is reduced from the set value (wS) by an amount equal to or greater than the power differential (wp) due to such power consumption control, the electrical equipment (Cn) (Cn-r) (Cn -* )... is outputted to increase the number of operating units so that they return to operation in the reverse order from when they stopped.

If the load condition returns to light load (l) or normal load (Hl) after going through this process of power consumption control,
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 by controlling the total power amount, and it is not possible to keep the power consumption below the set value by controlling the total power amount alone. Under conditions where the power consumption is not high, use power consumption control to forcibly stop the operation of electrical equipment with warm temperature control and lighting conditions, and ensure that the power consumption never exceeds the rated power of the power receiving equipment. It is managed as follows.

Therefore, such power consumption control and total power consumption control are based on the premise that the refrigerators included in the electrical equipment, and more specifically, the products in the load space maintained at low temperatures by each refrigerator, are not damaged. Large-scale integrated circuits (24
), an output signal is output through a sequence as shown in FIG. 4 that takes into consideration the temperature conditions of the load space related to the refrigerator that is subject to total power amount control and power consumption control, and defrosting conditions. In this case, part (xt) (
Kz) (K8), there are cases where no output signal is actually output.

That is, in FIG. 4, as in FIG. 2, (15) is a display light emitting diode, (16) is a power alarm, (18) is a used power recording device, (19') is a ROM power system storage section, ( 19”) is also the storage unit for total power amount control, (22
) is a detection converter for the input from the power sensor (22'), (
23) is the power consumption display, (26> is the temperature management logic, (32) is the AND logic, (33) is the OR logic, (Q4) is the stop time setting, (Q6) is the maximum allowable power setting, ( Q6) is the input device for power differential setting, (X') is the drive part of the relay (X), (35) is the power comparison part between the used power and the allowable power, and (3)
6) is a clock, (37) is a stop control unit, (38) is a display converter, (El) is a total power consumption control mechanism, (E,) is a power consumption control mechanism, (E3) is a defrosting signal, ( E4) indicates a temperature signal, and under this sequence, the total electric energy control mechanism (E4) is applied to the current electrical equipment at regular intervals.
, ), if the output signal comes out from the ROM (19)
After the temperature of the load space related to this electrical equipment falls below the set temperature according to the control sequence written in , If this electrical equipment is not related to defrosting, or if it is related but not defrosting, an output signal that is a forced stop permission signal is output from the temperature management logic (26), so the OR logic (
A receives an output signal which is a forced stop permission signal from 33).
The ND logic (32) outputs an output signal and drives the drive section (X'
) to indicate the stoppage of the electrical equipment due to the total power consumption control using the display light emitting diode (15), and also turn off the relay (X) to set the electrical equipment to the ROM (19').
), it is an actual stop for the set time written in the field, that is, a forced intermittent stop. This operation is also controlled by the power consumption control mechanism (
The same is true for the output signal from E,).

That is, according to this sequence, the electrical equipment to be controlled by the control mechanism is a refrigerator, and the defrosting signal (E,
> and temperature signal (E4) are not output and a forced stop permission signal is output from the temperature management logic (26),
When a forced stop signal is output from the total power consumption control mechanism (El) at regular intervals, the set time OR logic (33)
Then, the AND logic (32) inputs both matching signals, and the operation of the refrigerator is stopped for the set time. In addition, when the refrigerator is defrosting or has just been defrosted and the temperature of the product storage section, which is the load space, has just reached the set temperature, the defrost signal (E3) and the temperature Signal (E4)
does not enter the AND logic (32), so if the signal from the control mechanism (El) (E2) enters the OR logic (33)
Even if the compressor is output after the next total power consumption control cycle, the AND logic (32) is not activated, and the intermittent operation stop of the refrigerator can be avoided. There is no amount control, and temperature control logic (2
6), the compressor will not be stopped by power consumption control unless the condition is such that an output signal is output from 6).

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 can be performed when the supply of liquid refrigerant to the cooling heat exchanger is stopped. As a result, the rate of increase in the amount of frost that accumulates on the cooling heat exchanger as time passes during the cooling operation is extremely high, making it possible to reduce the number of forced defrosts, and also to reduce the amount of frost that accumulates during the cooling operation. Since the amount of heat exchanger is small, the cooling heat exchanger can operate at a high heat exchange rate and exhibit sufficient cooling performance.

[Brief explanation of the drawing]

The drawings show an embodiment of the method of operating the refrigerator of the present invention,
Fig. 1 is a configuration diagram of electrical equipment showing an example of power receiving equipment in a large-scale store, Fig. 2 is a block diagram showing electrical connections of the power supply control device according to the present invention, and Fig. 3 is a timer diagram showing an overview of the control. The chart diagram, FIG. 4, is a block diagram showing an example of the load management logic of the block diagram shown in FIG. 2. (R+ > (R*) - (RK) (RK+, ) - (Rn
-I) (Rnl...Refrigerating machine for showcase, (3)...
...Freezer for air conditioning, (4)...Freezer for cold storage warehouse,
(8)...centralized controller, (L,)...(Ln)
(L') (L'')...Load space, (25)...Load management logic.

Claims (1)

[Claims] 1. A cooling heat exchanger is placed in the product storage area, and the forced defrosting means is activated in a refrigerator that cools the load space with cold air obtained by exchanging heat with the cooling heat exchanger during operation of the refrigerator. During the cooling operation period between forced defrosts, cooling heat is removed. A method of operating a refrigerator that alternately supplies and stops liquid refrigerant to the exchanger.