JPS6050260B2 - Control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a cooling (or The invention relates to a device that controls cooling (or heating) of a heating) device.

Generally, there is a cooling system as shown in FIG. 1, in which a plurality of evaporators provided in a plurality of refrigerators are operated in parallel by one compressor.

In FIG. 1, reference numerals 1, 2, 3, and 4 are evaporators installed in different freezer or refrigerated showcases. The high temperature, high pressure gaseous refrigerant discharged from the compressor 5 is led to a condenser 6 and liquefied. The liquid refrigerant that has passed through the condenser 6 passes through a liquid pipe 8 to four electromagnetic valves SV, SV2, SV3, and SV provided corresponding to the evaporators 1, 2, 3, and 4. A branch input is made. The refrigerants that have passed through the four electromagnetic valves 5V and 5V4 are each depressurized by the expansion valve 7, and then guided to the corresponding evaporators 1, 2, 3, and 4, respectively.

In the evaporators 1, 2, 3, and 4, the refrigerant is vaporized and removes heat from the surroundings, thereby cooling the inside of each showcase. Evaporator 1,
The refrigerants passing through 2, 3, and 4 are led to the suction side of the compressor 5 through a suction pipe 9 in common. Solenoid valve SV,, SV2, S
When V3 and SV4 are energized, the valves open to allow refrigerant to pass through. Solenoid valves SV, SV in a cooling device capable of forming such a refrigerant circulation route.

, SV3, SV, there are conventional devices as follows. That is, a thermostat is provided in each showcase to perform the following temperature control. When the interior of a particular showcase is sufficiently cooled, a thermostat contact opens, cutting off power to the corresponding solenoid valve, stopping refrigerant from flowing into the evaporator, and raising the temperature.
Once the temperature is high enough, the thermostat contacts close, allowing refrigerant to flow through the corresponding solenoid valve to cool it again. In such a control circuit, the four electromagnetic valves are not related to each other and are independently controlled by their corresponding thermostat contacts. Therefore, the load on the cooling device is distributed and the load is reduced.
This results in low efficiency operation. The purpose of the present invention is to synchronize the opening and closing timing of each of the solenoid valves as much as possible, thereby preventing the load from being distributed and resulting in low load and low efficiency operation, concentrating the load, and increasing the efficiency of the operation. In addition to saving energy through low-load and high-efficiency operation, it also prevents overcooling (or overheating) that occurs when all loads are uniformly low, such as at night. The aim is to reduce power consumption loss due to overheating (overheating) and save energy. Embodiments of the present invention will be described below with reference to the drawings.

Fig. 2 shows the control device (Patent Application No. 55-1) which is the basis of the present invention.
32997).

This control device consists of four solenoid valves SVl shown in FIG.
, S■2, S■3, and S■4. In the figure, THl, TH2, TH3, and TH4 are the contacts of the thermostat installed in the showcase containing the evaporators 1, 2, 3, and 4, respectively! Ru. A thermostat opens a contact when the temperature inside the refrigerator falls below a predetermined lower limit (thermostat off value), and closes the contact when the temperature inside the refrigerator rises to or above a predetermined upper limit (thermostat on value). At first, if the temperature inside all the showcases is high, the thermostat contact TH
l, TH2, TH3, and TH4 are all closed. Therefore, relays RLl, RL2, RI-3, and RL4 are all energized and in operation, and their normally closed contacts R
Since ll, rl2, rl3, and rl4 are all open, delay relay 4 (ie, timer) TMl is not activated. Therefore, contact Tml of delay relay TMl is closed. Contact Tml is a normally closed contact that opens after a predetermined time when delay relay Tml is activated. At this time, solenoid valves SVl~S
Since power is supplied to V4 from the power supply 10 through the thermostat contacts THl to TH4 and the normally closed contact Tml, all the solenoid valves are open. Next, when the inside of one showcase (for example, a showcase equipped with evaporator 1) is sufficiently cooled, the thermostat contacts THl to T
Since thermostat contact THl of H4 opens, solenoid valve SVl of solenoid valves SVl to SV4 closes to stop the flow of refrigerant.

At the same time, relay relay RLl of relays RLl to RL4 becomes inactive, its normally closed contact Rll closes, and delay relay TMl becomes active. Even if the other load (showcase) cools down and the thermostat contacts TH2, TH3, or TH4 open while the delay relay TMl is operating,
Corresponding solenoid valve gate S■2, S■3, or SV
4 is closed, the corresponding relay RL2, RL3, or R
There is no effect on the operation of the timer or delay relay TMl, just because L4 is inactive. When the set time of the delay relay or timer TMl has elapsed, its normally closed contact Tml opens and all solenoid valves SVl to SV4
Cut off the power to.

Therefore, as the refrigerant stops flowing, the temperature inside all the showcases rises, causing the thermostat contact TH to rise.
1 to TH4 close one after another. However, delay relay TM
Since the normally closed contact Tml of l remains open, solenoid valve S
Vl to SV4 are not energized. At this time, the thermostat contacts of the showcase whose temperature has not decreased to the thermostat off value remain closed. When all thermostat contacts THl~THi are closed, relays RLl~RL
4 operate and all normally closed contacts Rll to Rl4 open, the power to delay relay TM1 is cut off, normally open contact Tml closes, and solenoid valves SV1 to SV4 are energized again.

In this way, we return to the starting state. If delay relay TML
All thermostat contacts THl~TH4 during operation
If it opens, the delay relay TMl will continue to operate, but the contact Tml will open while the temperature inside the showcase is rising, and in any case, the solenoid valves SVl to SV4 are not energized. , it's the same thing. All thermostat contacts THl during activation of delay relay TMl
~TH4 opens, and the temperature inside the showcase rises after that, causing all thermostat contacts THl~TH
Even if 4 is closed, the power to delay relay TM1 is cut off and the delay relay TM1 is placed in the initial state. On the other hand, compressor relay RI-,
When the normally open contact Rl5 of the compressor 5 is inserted and connected to the power supply circuit 11 of the compressor 5, and the relay RL5 is operated, the compressor 5 rotates and the relays R1-. When the compressor 5 becomes inactive, the compressor 5 is stopped. Compressor relay RL5 consists of a parallel circuit of normally open contacts rl″1 to r1″4 of relays RLl to RL4 and a delay relay T.
Since it is sandwiched between contact point Tml of Ml, it operates and rotates the compressor 5 only when one or more of the solenoid valves S1 to SV4 are open. Figure 3 shows the temperature change inside the showcase using this control circuit.

In this example, there are two load showcases, but the same applies if there are more than two load showcases. First, the temperature inside the showcase 1 (solid curve) has fallen sufficiently and the thermostat THl is turned on.
can be cut. As a result, the temperature inside the showcase 1 (solid line curve) starts to rise, but the inside temperature of the showcase 2 (broken line curve) continues to fall. When the thermostat THl of the showcase 1 is turned off and the set time t1 of the delay relay TMl has elapsed, cooling of the showcase 2 is also stopped. However, at this time, the temperature inside the showcase 2 has not fallen to the thermostat off value, so the thermostat contact TH2 remains closed. The temperature of both showcases 1 and 2 rises, and
When the temperature reaches the thermostat on value, the thermostat contact THl closes. At this time, since the thermostat contact TH2 of the showcase 2 remains closed, the delay relay TMl is disconnected from the power supply 10, and the temperatures of the showcases 1 and 2 begin to decrease. (See FIG. 3A) At this time, since showcase 2 was at a lower temperature, the temperature of showcase 2 reached the thermostat off value earlier than that of showcase 1, and thermostat TH2 was opened to stop cooling.

The delay relay TMl starts working from this point, but if the temperature of showcase 1 reaches the thermostat off value before the set time t1 has elapsed, the thermostat THl of showcase 1 also opens, and the thermostat contacts of both showcases 1 and 2 open. This means that Showcase 2 turned off earlier, so the temperature rose faster and reached the thermostat on value first. However, unless all the thermostats are turned on, the delay relay TM1 will not be opened, so the showcase 2 will not be cooled. The temperature of showcase 1 gradually rises and when it reaches the thermostat value, the delay relay TMl is also opened and the temperature of showcase 1 increases.
The temperature of both and 2 begins to drop. (See FIG. 3B) The temperature changes in the same manner thereafter, and the showcases 1 and 2 are cooled down at approximately the same time.

In this way, the control device shown in Fig. 2 prevents load distribution and low-load, low-efficiency operation by synchronizing the opening and closing timing of each solenoid valve as much as possible, and reduces the load. It is possible to achieve energy savings by concentrating the power supply, enabling high-load, high-efficiency operation. The present invention uses a control device as shown in Fig. 2 to prevent overcooling (or conversely, overheating when heating loads) that occurs when all loads are uniformly under low load conditions, such as at night. ) to prevent
This reduces power consumption loss due to overcooling (or overheating) and saves energy.

Hereinafter, a control device according to an embodiment of the present invention shown in FIG. 4 will be explained.

In Fig. 4, the part marked 100 corresponds to 100 in Fig. 2.
This is the same as the part shown in . Below, considering the case at night,
It is assumed that the day/night selector switch SW is closed. One of the thermostats THl to TH4 is turned off, and from that point on, the delay relay (first timer) TMl starts working, and after a certain period of time t1 has elapsed, the normally closed contact Tml opens and all the solenoid valves SVl to S4 close. The process up to this point is the same as in FIG. Next, when all the thermostats THl to TH4 are closed (turned on), cooling is restarted as shown in FIG. 2, but in this embodiment, all the thermostats THl to TH4 are turned on after the compressor 5 is stopped. The compressor 5 is characterized in that the compressor 5 is restarted after a further predetermined time T2 from the point in time. The day/night selector switch SW is closed. As in the case of Fig. 2, when one of the thermostats turns off, the normally closed contacts Rll of relays RLl to RL4
~Rl4) is closed, and energization of the delay relay (first timer) TMl is started. That is, the first detection circuit that detects that any one of the plurality of thermostats is turned off includes parallel connection circuits Rll to Rl4. When the delay relay TMl starts to be energized, the normally open contact Tm''1 of the delay relay TMl closes. When the set time of the delay relay (first timer) TMl has elapsed, the normally closed contact Tml opens. All solenoid valves SVl to SV4 are closed, compressor relay R1-. is also inactive, compressor 5 is stopped, and normally closed contact r1''5 of relay RL5 is also closed. That is, when the first timer TMl measures the predetermined time t1, all the solenoid valves SVl~
The first step is to close the SV4 and stop the compressor 5.
The control circuit includes Tml. In this way, Tm″
1-RY5-Sw-Delay relay (second timer) TM
A circuit of two normally closed contacts Tm2-TMl is formed. The above-mentioned normally closed contact Tm2 is a delay relay (second timer) TM
2 is a contact that opens after a predetermined period of time after activation. Since the above-mentioned circuit is formed, even if the internal temperature of all showcases rises, relays RLl to RL4 operate, and all normally closed contacts Rll to Rl4 open, the delay relay (first
timer) TMl is not released. The temperature of all showcases rises and all thermostats THL~T
When F[4 is turned on, delay relay TMl is not opened, but at that point all normally open contacts r1''1 to r1''4 of relays RLl to RL4 are closed, so delay relay TM2 starts operating. . That is, the second detection circuit that detects that all the thermostats are turned on after the compressor 5 has stopped has Tm''1, rl''5, and rl''1 to rl.
At this point, the normally closed contact Tm''2 of the delay relay TM2 opens, but since the normally closed contact Tml is already open, it has no effect on the operation. Normally closed contact Tm2 opens after a certain period of time T2 after delay relay TIS/12 is energized! Therefore, the power to delay relay TMl is cut off. (The temperature in the showcase is rising, so
Normally closed contacts Rll-Rl4 of relays RLl-RL4 remain open. ) At that point, the normally open contact Tm''1 of the delay relay TMl also opens, the power to the delay relay TM2 is also cut off, and the normally closed contacts Tm, and normally closed contacts Tm''2 close one after another (albeit for a moment). , returns to the initial state and begins cooling.
That is, the second control circuit restarts the compressor 5 when the second timer TM2 measures the predetermined time T2.
2, Tme, and Tm″2. If the temperature of all the showcases rises and the thermostats are turned on while the delay relay TMl is operating (within a period of time), then Tm″1−r′5− Sw-r1″1~r1″″4
-The circuit of TM2 is formed, and from this point the delay relay T
Regardless of the time of Ml, delay relay TM2 starts operating and closes the solenoid valve. Normally closed contact T of delay relay TML
ml does not open until 1 sin has passed at the time of setting, but the normally closed contact Tm''2 of delay relay TM2 opens at the same time as the start of energization to delay relay TM2, so solenoid valves SVl to SV4 close,
Compressor 5 stops. The day/night changeover switch SW may be turned on or off manually, or may be turned on and off by a 24-hour timer. Or, as shown in Figure 5, the showcase lighting power supply 1
) If you connect day/night changeover relay RL6 in parallel to ).If the day/night selector switch SW is turned off (if it is set for daytime use), the circuit in Fig. 4 becomes the second
The circuit will be exactly the same as the one shown in the figure. FIG. 6 shows temperature changes when the control device of this embodiment is used.

The number of showcases is two, showcase 1 and showcase 2. First, the temperature of showcase 1 drops faster than showcase 2, and the thermostat turns off. From this point on, cooling of all showcases is stopped after the time set by the first timer TMl. At this time, the thermostat of the showcase 2 has not reached the thermostat off point, so the thermostat remains on. When the temperatures of the two showcases rise and the temperature of the showcase 1 reaches the ON point, the compressor 5 is forcibly stopped from that point on for the time set by the second timer TM2.

Showcase 2's thermostat remains on. (
FIG. 6, Part A) After time T2, the two showcases begin to cool down, and showcase 2 reaches the thermostat off point first.

Within hours from that point, the thermostat of showcase 1 will also be turned off. In this way, the temperatures of the two showcases rise, and the thermostat of showcase 2 turns on first. Next, the thermostat of showcase 1 is turned on. From the time when these two thermostats are turned on, cooling is still stopped for the time T2. After T2 has elapsed, both showcases 1 and 2 begin to cool down. Repeat the same process below. The above is the nighttime situation. It can be seen that the daytime temperature is as shown in Figure 3, and the average temperature is higher at night as shown in Figure 6.

In addition, in FIG. 2, malfunction may occur depending on how the electrical resistances of the relays RLl to RL4 and the electrical resistances of the solenoid valves SVl to SV4 are selected.

For example, if contact Tml is open and thermostat contact '
If only NIl is closed, normally only relay RLl should be activated, but other relays may also be activated. In other words, a circuit in which current flows (that is, a current loop circuit) is formed through the thermostat contact THl, the solenoid valve SVl, the solenoid valve SV2, and the relay RL2. At this time, if the electrical resistance of the solenoid valves SVl and SV2 is large, the voltage applied to the relay RL2 becomes lower than the operating voltage of the relay R1-2, and the relay RL2 does not operate. However, as the electrical resistance of the solenoid valves SVl and SV2 decreases, the voltage applied to the relay RL2 increases and eventually reaches the operating voltage. Relay RLl under any conditions
~In order to operate RL4 accurately without malfunction, it is necessary to do as shown in FIG. In Fig. 7, relay RL
7 is activated by the contact Tml of the timer TM1. The normally open contact Rl7 of relay RL7 is closed when relay RL7 is activated, so when Tml is closed, Rl7 is also closed.
Therefore, in the same way as when contact Trrll in FIG. 2 opens, when contact Tml opens, relay contact Rl7 opens, and solenoid valve SV
l~S■4 and relay RI-. Power is cut off. In the circuit shown in FIG. 7, the current loop circuit described above is not formed. FIG. 8 shows an embodiment in which the present invention is applied to the circuit shown in FIG. 7. In FIG. 8, the portion indicated by 10'' is the same as the portion indicated by 10'' in FIG. In FIG. 8, the contact Tml is used instead of the contact Tm in FIG.
and the normally closed contact Tm″2 of the second timer TM2 (same as the one in FIG. 4) are connected in series. The circuit in FIG. 8 also operates essentially the same as the embodiment in FIG. 4. The effects of the present invention will be listed below.

(1) If there is a thermostatic temperature sensing part in the showcase air curtain, the temperature of the showcase air curtain will be constant throughout the day, but disturbances (due to products or hands coming in and out) will be reduced by turning off the lights inside the showcase. By doing so, the showcase will be cooler at night.

Therefore, by raising the set temperature at night using the control device of the present invention, overcooling can be prevented and energy savings can be achieved. (2) Even if a temperature-sensitive thermostat is set inside the showcase to keep the temperature constant, the temperature of the product will drop at night because there is no radiant heat from lighting. Therefore, by using the control device of the present invention, it is possible to actively raise the temperature inside the refrigerator, prevent overcooling of the items, and achieve energy savings. (3) There is a thermostat (dual thermostat) that can set a temperature difference between day and night, but this must be installed for each load.

In the control device of the present invention, by using as many inexpensive ordinary thermostats as there are loads, it is possible to simultaneously achieve the energy saving effects of preventing overcooling at night and synchronizing the operation of the solenoid valves. The control device of the present invention can be used in a cooling device in which a compressor and a condenser are combined into one unit and a plurality of evaporators are connected, such as a refrigerator, a refrigerator, a room cooler for cooling multiple rooms, and the like.

Furthermore, the control device of the present invention is of a heat pump type that releases heat, and includes a compressor and an evaporator as a unit.
It can be used in a heating device in which a plurality of condensers are connected, such as a multi-room heating device.

In this case, the connection of the thermostat is such that, contrary to the above-described embodiment, the connection of the thermostat is turned off when the temperature rises above the upper limit of a predetermined temperature, and is turned on when the temperature falls below the lower limit of the predetermined temperature.

[Brief explanation of the drawing]

Figure 1 is a refrigerant circulation system diagram of a cooling system in which multiple evaporators installed in multiple refrigerators are operated in parallel with one compressor.
The figure is a circuit diagram of the control device that is the basis of the present invention, and FIG. 3 is a time chart diagram showing control by the control device of FIG. 2.
FIG. 4 is a circuit diagram of a control device according to one embodiment of the present invention, FIG. 5 is a diagram for explaining another embodiment of the present invention, and FIG. 6 shows control by the control device of FIG. 4. It is a time chart figure. FIG. 7 is a circuit diagram showing a modification of FIG. 2, and FIG. 8 is a circuit diagram of a control device according to another embodiment of the present invention. 1, 2,
3, 4... Evaporator, 5... Compressor,
6... Condenser, 7... Expansion valve, 8...
...Liquid pipe, 9...Suction pipe, 10...Power supply,
1... Showcase lighting power supply, 11... Compressor power supply circuit, S■1 to S■4... Solenoid valve,
THl~TH4...Thermostat contact, RL
l~RL)●Plate●Lilleni, Rll~Rl49rv5●●
...Normally closed contacts of relays RLl to RL5, r1″1 to r1″
4, r15... Normally open contacts of relays RN-1 to RL5, r1''1 to r1''''4... Relay RLl~
Normally open contact of RL4, TMl...First timer (delay relay), Tml and Tm''1... Contact of timer TMl, TM,... Second timer (delay relay), Tm2 and h″2...timer TM2 contact, R1...relay, SW...
...Day/night switch.

Claims (1)

[Claims] 1 Multiple evaporators (or condensers) from one compressor
In a control device for a cooling (or heating) device that cools (or heats) multiple loads by supplying compressed gas to the The first state is established when the temperature of each load falls below the lower limit of a predetermined temperature (or rises above the upper limit of the predetermined temperature). and, conversely, a plurality of thermostats that enter a second state when the temperature rises above the upper limit of the predetermined temperature (or falls below the lower limit of the predetermined temperature), and one of the thermostats among the plurality of thermostats. is connected to the first detection circuit, starts working at the time of detection by the first detection circuit, and starts to operate from the detection time to the first state. a first timer that measures a predetermined time;
a first control circuit that closes all of the solenoid valves and stops the compressor when the first timer measures the first predetermined time; and a first control circuit that closes all of the solenoid valves and stops the compressor when the first timer measures the first predetermined time; is connected to the second detection circuit, starts working at the time of detection by the second detection circuit, and starts to operate from the time of detection to the second detection circuit. A control device comprising: a second timer that measures a predetermined time; and a second control circuit that restarts the compressor when the second timer measures the second predetermined time.