JP3931499B2 - Energy-saving operation method of cooling compressor and energy-saving vending machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an energy-saving operation method and an energy-saving vending machine for a cooling compressor that includes a compressor and an evaporator and cools a plurality of rooms.
[0002]
[Prior art]
When cooling a plurality of rooms with a common compressor, in order to supply the refrigerant in only one of the chambers, the compressor must be operated in the same manner as when the refrigerant is supplied to the plurality of chambers. Therefore, in the prior art, when cooling a plurality of chambers, when the temperature difference between the rooms opens to a predetermined specified temperature difference, the supply of the refrigerant to the low temperature room is stopped, and the temperature difference disappears. In addition, an operation method has been adopted in which the cooling of the plurality of chambers is started again, the timing of supplying the refrigerant to the plurality of chambers is aligned, and the time during which the compressor operates is reduced.
[0003]
FIG. 4 shows an internal temperature characteristic diagram during a three-chamber cooling operation as an example according to the conventional operation method, FIG. 5 shows a control flowchart according to the conventional operation method, and FIG. 6 shows the configuration of the vending machine according to the conventional technology and the present invention. The figure is shown.
[0004]
6A, the vending machine 1 has a plurality of rooms controlled in a predetermined temperature range Tu to Td, in the illustrated example, three rooms (1A, 1B, 1C). 1A, 1B, 1C) includes a shutoff valve 22 that receives supply of the refrigerant 24 from the refrigerator 2A and controls conduction / cutoff of the refrigerant 24, and an evaporator 21 that vaporizes the refrigerant 24 and cools the room. Composed. Further, the refrigerator 2A includes a compressor 25, a condenser 26, a dryer 27, a capillary tube or an expansion valve 28, each of these devices 25 to 28, a shutoff valve 22 and an evaporator 21 in each of the rooms (1A, 1B, 1C). Are connected in series with each other and connected in parallel to form a circulation line 23 for the refrigerant 24, and the refrigerant 24 circulates in these devices.
[0005]
In FIG. 4, temperature is plotted on the vertical axis and time is plotted on the horizontal axis. Assume that at the time t40, the three rooms (1A, 1B, 1C) are simultaneously cooled from the upper limit value Tu of the temperature range. The thermal time constants of the three rooms (1A, 1B, 1C) (depending on the specific heat and storage capacity of the products stored in each room) are T1a, T1b, T1c, and T1a>T1b> T1c. The cooling capacity of the refrigerator 2A is such that the ultimate temperature when the three chambers (1A, 1B, 1C) are simultaneously cooled can fall below the lower limit value Td of the temperature range.
[0006]
The control flowchart of FIG. 5 will be described below with reference to FIG. In FIG. 5, under the conditions as described above, the temperature Tc of the chamber 1C decreases most quickly, and the temperature Ta of the chamber 1A decreases most slowly. In step s21, the chamber temperatures (Ta, Tb, Tc) of the three chambers (1A, 1B, 1C) are measured. In step s22, the chamber temperatures (Ta, Tb, Tc) of the three chambers (1A, 1B, 1C) are measured. Determines whether the temperature is higher than the target temperature lower limit value Td. If the temperature is Yes, the process proceeds to step s23 to determine whether the temperature difference between any two chambers is equal to or greater than the specified temperature difference ΔT. Returning to s21, in step s23, the temperature difference between any two chambers is checked for Yes over the specified temperature difference ΔT. At time t41, the temperature difference between the temperature Ta of the chamber 1A and the temperature Tc of the chamber 1C is detected to be Yes over the specified temperature difference ΔT, and the process proceeds to step s24. In step s24, the cooling of the room 1C having the lowest room temperature Tc is turned off, and it is determined whether or not the lowest room temperature Tc of the room 1C in which the cooling is turned off in step s25 has reached the temperature of any one room (1B in the illustrated example). If No, the process returns to step s24, and in step s25, the temperature of one chamber (1B) is reached and Yes is checked. At time t42, Tc = Tb is detected and the process proceeds to step s26, and cooling is turned on for all three chambers (1A, 1B, 1C) and the process returns to step s21. Monitor whether Td has been reached.
[0007]
When the temperature Tc of the chamber 1C having a small thermal time constant reaches the target temperature lower limit value Td at time t43 and this is detected in step s22, the process proceeds to step s31. In step s31, the cooling of the chamber 1C that has reached the target temperature lower limit value Td is turned off, and the cooling of the remaining two chambers (1A, 1B) having a temperature higher than the target temperature lower limit value Td is turned on. In step s32, it is determined whether or not these two chambers (1A, 1B) are both higher than the target temperature lower limit value Td. If the temperature is Yes, the chamber internal temperature (Ta, Tb) of the two chambers (1A, 1B) is determined in step s33. It is determined whether or not the temperature difference between the two chambers (1A, 1B) is greater than the specified temperature difference ΔT and Yes is checked in step s33. . In the illustrated example, since the temperature difference between the two chambers (1A, 1B) does not occur more than the specified temperature difference ΔT in step s33, there is no flow from step s34 to step s36, but if the specified temperature difference ΔT is exceeded, Yes is generated. For example, in the same manner as described in steps s24 to s26, the cooling of the low temperature side room is turned off in step s34, and it is determined in step s35 whether the temperature difference between the two rooms (1A, 1B) has reached 0 deg. If No, the process returns to step s34, and in step s35, the temperature difference is checked for 0 deg Yes. Then, the process proceeds to step s36, the cooling is turned on in both the chambers (1A, 1B), the process returns to step s31, and it is monitored whether any one of the chambers in step s32 has reached the target temperature lower limit value Td. .
[0008]
When the temperature Tb of the chamber 1B reaches the target temperature lower limit value Td at time t44 and is detected in step s32, the process proceeds to step s41. In step s41, the cooling of the chamber 1B that has reached the target temperature lower limit value Td is turned off, and the remaining one chamber (1A) having a temperature higher than the target temperature lower limit value Td is turned on. In step s42, it is determined whether or not this chamber (1A) has reached the target temperature lower limit value Td.When the lower limit value Td has been reached, the process returns to step s41, and in step s42, the chamber (1A) has reached the lower limit value Td. Monitor whether or not.
[0009]
At time t45, the temperature Ta of the room 1A reaches the target temperature lower limit value Td, and when this is detected in step s42, the process proceeds to step s44 and cooling is turned off for all three rooms (1A, 1B, 1C). Stop the compressor 25. Then, the process proceeds to step s48 to determine whether any of the three rooms (1A, 1B, 1C) has reached the target temperature upper limit Tu. If the target temperature upper limit Tu is reached No, the process returns to step s44, and in step s48, it is monitored whether any of the three rooms (1A, 1B, 1C) has reached the target temperature upper limit Tu.
[0010]
In the illustrated example, when the room 1C reaches the target temperature upper limit Tu at the time t46, this is detected in step s49, the compressor 25 of the refrigerator is started, and all the three rooms (1A, 1B, 1C) are activated. Cooling is turned ON at the same time, and the process returns to step s21.
[0011]
Thereafter, the same control is performed, and the internal temperature (Ta, Tb, Tc) of the three chambers (1A, 1B, 1C) can be controlled and maintained within the target temperature range (Tu to Td).
[0012]
[Problems to be solved by the invention]
In such an operation method according to the prior art, a plurality of chambers are cooled at the same time unless the temperature difference between the rooms reaches a specified temperature difference ΔT. Since the refrigerant supplied to each room at this time is distributed to each room, the amount of refrigerant supplied per room is reduced. On the other hand, the lower the internal temperature, the slower the cooling rate and the longer it takes to cool down. Therefore, even if the compressor of the refrigerator is turned on and turned on, multiple chambers are simultaneously cooled near the lower limit of the target temperature range, which takes the longest to cool, and cooling is performed over a short temperature for a long time. It may become.
[0013]
The present invention has been made in view of the above points. The object of the present invention is to solve the above-described problems, shorten the compressor ON time near the lower limit of the target temperature range, and provide a cooling compressor that performs energy saving operation. It is to provide an energy saving operation method and an energy saving type vending machine.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention controls the operation of a refrigerator that performs cooling using a cycle of refrigerant evaporation and condensate liquefaction to cool a plurality of rooms, and the temperature of each room is determined in advance. In the energy saving operation method of the cooling compressor that is maintained and controlled within the specified temperature range, the cooling operation control for a plurality of rooms is performed for one operation period consisting of a simultaneous operation period, a one-room operation period, and an operation stop period. The control temperature parameter of the room to be controlled by cooling has a specified temperature, an upper limit value, and a lower limit value. When the temperature of any one of a plurality of rooms reaches the upper limit value, the compressor is started. Multiple rooms are cooled at the same time (simultaneous operation), and as a result of the simultaneous operation, when any room reaches a specified temperature value, only one room is selected according to a predetermined selection criterion, and this is cooled (one room) operation) When the temperature of the selected room reaches the lower limit as a result of the operation of this one room, the cooling of this room is stopped, the other one room is sequentially selected according to the selection criteria, and the one room operation is performed. After all the rooms have been operated in one room, when the temperature of the last selected room reaches the lower limit, the compressor is stopped and the cooling of all the rooms is stopped (stopped).
[0015]
In addition, the specified temperature can be selected as a temperature value that causes a difference in the cooling rate of the temperature in the room when a plurality of rooms are simultaneously cooled and when only one room is selected and cooled. it can.
[0016]
With this configuration, when one of the rooms reaches the specified temperature, only one room is selected and concentrated according to a predetermined selection criterion, and this is cooled to the lower limit value. Thus, the compressor can be rapidly cooled to the lower limit value of the temperature range, so that the ON time of the compressor near the lower limit value of the target temperature range can be shortened.
[0017]
As a selection criterion for a room to be cooled by selecting only one room, it is possible to select a room having the highest temperature when reaching a specified temperature or a lower limit value.
[0018]
The selection criteria for the room to be selected and cooled can be selected in the order of the room having the largest thermal time constant except for the room that has reached the lower limit.
[0019]
With this configuration, except for the room that has reached the lower limit, by cooling one room in the order from the room with the highest temperature or the room with the largest thermal time constant, (1) at least several times the number of rooms Rapid cooling can be achieved by increasing the cooling rate. (2) Cool first from a room with a high temperature or a room with a large thermal time constant that is difficult to decrease. (3) Start with a room that has a slow temperature rise when cooling is turned off (a room with a large thermal time constant). Since cooling is performed, when one of the rooms reaches the upper limit value and the compressor is started, the temperature of each room can be roughly adjusted to a temperature close to the upper limit value.
[0020]
In addition, energy-saving vending machines using the above-mentioned cooling compressor energy-saving operation method Because Each room has a plurality of rooms controlled to a predetermined temperature range. Each room is supplied with a refrigerant from a refrigerator, and a shutoff valve that controls conduction / cutoff of the refrigerant, vaporizes the refrigerant, and cools the room. An evaporator, and a refrigerator Configure the above cooling compressor With compressor , With a condenser , With dryer , With capillary tube or expansion valve , With each of these devices A pipe that connects the shut-off valve and the evaporator in one room in series, a pipe that connects the shut-off valve and the evaporator in parallel to the pipe that connects the shut-off valve and the evaporator, and configures a circulation system; And a refrigerant circulating in these devices.
[0021]
Energy-saving vending machines that use energy-saving operation methods for cooling compressors Because Each room has a plurality of rooms controlled to a predetermined temperature range, each room is supplied with cold air cooled by an evaporator of the refrigerator, and includes a control valve for ON-OFF control of the cold air. , Constituting the above cooling compressor With compressor , With a condenser , With dryer , Capillary tube or expansion valve and evaporator, piping connecting these devices, constituting a circulation system, refrigerant circulating in these devices, fan for sucking and blowing air cooled by the evaporator, and this It can comprise and comprise a ventilation system which consists of a duct which connects cold air to a control valve of each room.
[0022]
With this configuration, when one room is operated, the total refrigerating capacity of the refrigerator can be injected into the cooling of the selected one room, and the heat of vaporization that evaporates by absorbing the heat from the periphery of the evaporator in the room. As the amount of heat absorbed can be increased, or the amount of cold air supplied to cool one room can be increased, the final cooling temperature when operating all rooms simultaneously is more than the final cooling temperature when operating one room. Can be set to a lower temperature side, and cooling can be performed with characteristics almost linearly toward the lower limit value of the temperature range, so that the cooling time can be improved and the ON time of the compressor can be reduced.
[0023]
In addition, the cooling compressor In energy saving operation method, The room selection criteria for selecting and cooling only one room in the order of the room with the largest thermal time constant except for the room that has reached the lower limit value is one room operation, and after reaching the lower limit value, the cooling is stopped and the temperature rise characteristics of the room Selection can be ranked.
[0024]
With this configuration, the storage capacity of products that affect the thermal time constant in each room of the vending machine is automatically stopped after reaching the lower limit of the target temperature range, and the temperature rise characteristics of the room are equivalent. By obtaining and ranking the selection, the ranking of the selection can be automatically changed according to the sales amount of the product.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an internal temperature characteristic diagram during a three-chamber cooling operation for explaining an energy saving operation method of a cooling compressor as one embodiment of the present invention, and FIG. 2 is a graph showing a case where the cooling capacity of the refrigerator is slightly insufficient. FIG. 3 is a control flow chart according to the operation method of the present invention, and the same members corresponding to FIGS. 4 to 6 are denoted by the same reference numerals. In addition, the code | symbol of the vending machine of FIG.
[0026]
In FIG. 1 and FIG. 6, a plurality of rooms (1A, 1B, 1C,...) Are cooled by operating and controlling a refrigerator 2A that performs cooling using a cycle of evaporation and condensing of refrigerant 24. In the energy-saving operation method of the cooling compressor that maintains and controls the temperature within a predetermined temperature range (Tu to Td), the cooling operation control of multiple rooms (1A, 1B, 1C,. An operation period consisting of a one-room operation period and an operation stop period is defined as one operation cycle, and a specified temperature Ts, an upper limit value Tu, and a lower limit value Td are set as control temperature parameters of the room to be cooled. Have
When the temperature of any of the multiple rooms (1A, 1B, 1C,...) Reaches the upper limit Tu, the multiple rooms (1A, 1B, 1C,...) Are simultaneously cooled (simultaneous operation) ) As a result of this simultaneous operation, when any room (for example, 1C) reaches the specified temperature value Ts, only one room (for example, 1A) is selected and cooled according to a predetermined selection criterion (one room). Operation), when the temperature of the selected room (1A) reaches the lower limit Td as a result of operating this one room, the cooling of this room (1A) is stopped and the other room (for example, 1B) is stopped according to the selection criteria. Select one after another and operate one room. After operating all the rooms in one room, the compressor 25 is stopped when the temperature of the last selected room (for example, 1C) reaches the lower limit. Stop cooling all rooms (1A, 1B, 1C, ...)
When the temperature of any of the rooms (1A, 1B, 1C, ...) reaches a predetermined upper limit Tu, the compressor 25 is activated and all the rooms (1A, 1B, 1C, ...) By cooling at the same time and repeating this control cycle, multiple rooms (1A, 1B, 1C,...) Are cooled, and the temperature of each room is maintained and controlled within a predetermined temperature range (Tu to Td). Can be
[0027]
The specified temperature Ts differs between the cooling rate in the room when multiple rooms (1A, 1B, 1C, ...) are cooled at the same time and when only one room is selected and cooled. The resulting temperature value can be selected.
[0028]
With this configuration, when any room (for example, 1C) reaches the specified temperature Ts, only one room (for example, 1A) is selected and cooled to the lower limit value Td according to a predetermined selection criterion, and the remaining ones are sequentially left. Since only one room can be selected and the temperature can be rapidly cooled to the lower limit value Ts of the temperature range, the time required for the temperature to drop in the vicinity of the lower limit value of the target temperature range in the prior art can be reduced. The ON time of the compressor 25 can be shortened.
[0029]
【Example】
First, the configuration of the refrigerator 2A and the cooling principle will be described. In FIG. 6, the refrigerator 2A connects the compressor 25, the condenser 26, the dryer 27, the capillary tube or expansion valve 28, the evaporator 21, and these devices 21, 25 to 28 as described above. A cooling device comprising a piping 23 constituting a circulation system, and a refrigerant 24 (24 g, 24 L) that is charged in the cooling device and circulates in the devices 21, 25 to 28 and evaporates and cools in the evaporator 21. ).
[0030]
With this configuration, the refrigerator 2A is cooled using a cycle of evaporation of the refrigerant 24 and condensation. The refrigerant liquid 24L evaporates in the evaporator 21 at a temperature corresponding to the pressure. At this time, if the temperature of the evaporator 21 is lower than the ambient temperature, the heat continues to be absorbed from the surroundings to evaporate. If the pressure of the evaporator 21 is kept constant, it can be kept at a constant temperature corresponding to this pressure. The refrigerant liquid 24L is depressurized by the expansion valve 28 and sent to the low-pressure evaporator 21, where the surrounding heat is absorbed and evaporated, and the generated steam 24g is sucked into the compressor 25 and compressed by the power applied to the compressor 25. 24g of high-pressure and high-temperature gas is led to the condenser 26, liquefied by dissipating heat to water / atmosphere, etc., received in the reservoir, and this is led to the expansion valve 28 described above, and the cooling cycle is It is formed.
[0031]
The refrigerant 24 (24g, 24L) is a medium for transferring heat, and in this case, the state of the refrigerant 24 only changes to gaseous (24g) or liquid (24L). By repeating this cycle, the temperature of the object in a limited portion around the evaporator 21 can be lowered to generate refrigeration (cooling). That is, the refrigeration cycle spends work, absorbs heat at a low temperature location (evaporator 21), and combines it with heat corresponding to the work spent at a high temperature location (condenser 26). Dissipate heat. The compressor 25 functions as a heat pump that pumps heat by the applied power.
[0032]
In this way, in the evaporator 21, when the pressure of the liquid refrigerant 24L is kept low, the liquid refrigerant 24L evaporates at a low temperature.At this time, the liquid refrigerant 24L evaporates, and a large amount of heat is required. Because it takes away heat and evaporates, the surroundings can be cooled. In the present invention, during one room operation, all the refrigerant 24 is absorbed and evaporated by the evaporator 21 in this room, so that the room temperature can be rapidly lowered. While the liquid refrigerant 24L is evaporated and vaporized, the evaporation temperature with respect to the pressure is constant, and the deprived heat is consumed for the state change (liquid to gas).
[0033]
Further, the compressor 25 sucks into the cylinder the vapor of the refrigerant 24g that evaporates more and more in the evaporator 21, so that the evaporator 21 can always be kept at a low pressure and the evaporation temperature of the refrigerant 24g can be kept low. In order to discharge a large amount of heat from the gaseous refrigerant 24g, which is a heat carrier, heat can be easily released by increasing the pressure to increase the condensation temperature and higher than the outside air.
[0034]
The condenser 26 can cool and liquefy 24 g of the gaseous refrigerant that has been heated to high temperature and pressure by the compressor 25 with ambient air or water at room temperature. When the gaseous refrigerant 24g condenses and returns to the liquid refrigerant 24L, the latent heat of condensation is released to the outside air or water. Accordingly, the temperature of the liquid refrigerant 24L itself in the condenser 26 does not change much.
[0035]
The dryer 27 removes moisture, dust, and the like contained in the liquid refrigerant 24L, prevents a deterioration in the quality of the refrigerants 24g and 24L, and enables the refrigerants 24g and 24L to be recycled.
[0036]
Since the pressure of the capillary tube or the expansion valve 28 is too high if the refrigerant 24L liquefied by the condenser 26 is used as it is, the pressure is reduced to a pressure at which the evaporator 21 can easily evaporate. Either the capillary tube or the expansion valve 28 resists through a narrow passage, and the pressure of the refrigerant 24L suddenly drops due to a change in throttle. Due to the squeezing effect, a part of the refrigerant 24L evaporates to generate bubbles 33. At this time, the evaporation is performed by taking away the heat of the refrigerant liquid 24L itself, not the heat from the outside.
Example 1
FIG. 6 is a block diagram of a vending machine according to an embodiment of the present invention. 6A, the vending machine 1 has a plurality of rooms controlled in a predetermined temperature range Tu to Td, in the illustrated example, three rooms (1A, 1B, 1C). 1A, 1B, 1C) includes a shutoff valve 22 that receives supply of the refrigerant 24 from the refrigerator 2A and controls conduction / cutoff of the refrigerant 24, and an evaporator 21 that vaporizes the refrigerant 24 and cools the room. Composed. Further, the refrigerator 2A includes a compressor 25, a condenser 26, a dryer 27, a capillary tube or an expansion valve 28, each of these devices 25 to 28, a shutoff valve 22 and an evaporator 21 in each of the rooms (1A, 1B, 1C). Are connected in parallel to each other to form a circulation system for the refrigerant 24, and the refrigerant 24 circulates in these devices. In the following example, the number of rooms of the vending machine 1 described in FIGS. 1 to 3 will be described in the case of three rooms (1A, 1B, 1C).
[0037]
In FIG. 1, temperature is plotted on the vertical axis and time is plotted on the horizontal axis, and the time-varying characteristics of each room temperature (Ta, Tb, Tc) are shown by thick lines, and the characteristics shown by the dotted lines are turned on or off for cooling. Indicates the state as it is. Assume that at the time t10, the three chambers (1A, 1B, 1C) are simultaneously cooled from the upper limit Tu of the temperature range. The thermal time constants of the three rooms (1A, 1B, 1C) (depending on the specific heat and storage capacity of the products stored in each room) are T1a, T1b, T1c, and T1a>T1b> T1c, The cooling capacity of the refrigerator 2A is such that the ultimate temperature when the three chambers (1A, 1B, 1C) are simultaneously cooled can be close to or lower than the lower limit value Td of the temperature range. In the following description, the selection criteria for the room to be cooled by selecting only one room are selected as the room having the highest temperature when the specified temperature Ts or the lower limit Td is reached, and one room is operated, and the remaining room is selected. It is assumed that the room shuts off the cooling by shutting off the refrigerant 24 with the shut-off valve 22.
[0038]
Under the conditions as described above, when the three chambers (1A, 1B, 1C) are simultaneously cooled at time t10, the temperature Tc of the chamber 1C is decreased most quickly, and the temperature Ta of the chamber 1A is decreased most slowly. The chamber temperature (Ta, Tb, Tc) of the three rooms (1A, 1B, 1C) is measured, and one of the three rooms (1A, 1B, 1C) at the time t11 (1C in the example shown) When the inside temperature (Tc) reaches the specified temperature Ts, the room 1A having the highest room temperature at the time t11 is operated as one room, and the supply of the refrigerant 24 in the other rooms 1B and 1C is stopped. Since all the refrigerant 24 is supplied to the room 1A having the highest room temperature, the rate of temperature drop in the chamber is faster than the simultaneous cooling of multiple rooms, and the temperature (Ta) of one room (1A) is the lower temperature limit. Even when approaching Td, the internal temperature drop rate can be maintained higher than when cooling multiple rooms simultaneously.
[0039]
When one room 1A is operated and the internal temperature Ta reaches the lower limit Td at time t12, one room 1B having the highest room temperature at this time t12 is operated, and the refrigerant 24 of the other rooms 1A and 1C is supplied. Stop. As in the case of the one room 1A described above, the room 1B that showed the intermediate room temperature Tb at the time t11 when the refrigerant 24 was concentrated has a high internal temperature decrease rate, and the speed does not decrease so much at the time t13. The lower limit value Td is reached. At this time t13, the room 1C having the highest room temperature, that is, in the example shown in the figure, is the cooling of the three rooms, so the last remaining room 1C is operated, and the supply of the refrigerant 24 in the other rooms 1A, 1B is stopped. At time t14, the internal temperature Tc reaches the lower limit value Td. In this way, in the one-room operation, the room to be cooled next is selected from the room having the highest internal temperature at that time, so that the temperature of the remaining room not operating in the one-room is reduced. The cooling time can be made as short as possible when the temperature is lowered as much as possible and the next one-chamber cooling operation is performed.
[0040]
In this way, when all three rooms (1A, 1B, 1C) have reached the lower limit cooling temperature value Td, the compressor 25 is stopped and the cooling of all rooms (1A, 1B, 1C,. To stop. The compressor 25 is constantly in the ON state during a period ton from the start of cooling (simultaneous operation) of all the rooms (1A, 1B, 1C,...) Until the end of (single-room operation).
[0041]
As described above, the timing at which the supply of the refrigerant 24 to each room stops is shifted from t12, t13, and t14, so that there is a difference in the internal temperature rise after the compressor 25 is stopped. However, when the inside temperature rises, the cause of this rise in the inside temperature depends only on the intrusion of heat from outside the warehouse, and the higher the inside temperature, the slower the inside temperature. The temperature difference between the room (1A) where the supply of the refrigerant 24 was stopped and the room (1C) where the supply of the refrigerant 24 was stopped later is reduced.
[0042]
When the temperature of any one of the three rooms (1A, 1B, 1C) (the room 1C in the illustrated example) reaches a predetermined upper limit Tu, the compressor 25 is activated and all the rooms (1A, 1C, 1B, 1C, ・) are cooled at the same time (simultaneous operation), and this control cycle is repeated to cool multiple rooms (1A, 1B, 1C), and the temperature of each room (1A, 1B, 1C) It can be maintained and controlled within a predetermined temperature range (Tu to Td).
[0043]
The reason for starting the compressor 25 and operating all rooms (1A, 1B, 1C, ..) simultaneously when the temperature of any of the three rooms (1A, 1B, 1C) reaches the upper limit Tu Is
(1) In order to supply the refrigerant 24 to any one chamber (1C), the compressor 25 must be started.
[0044]
(2) Also, if the refrigerant 24 is supplied to one chamber (1C), the refrigerant 24 is supplied until the chamber (1A, 1B) that has not reached the upper limit Tu of the internal temperature reaches the upper limit Tu. Na No In this case, the temperature difference between the three chambers (1A, 1B, 1C) widens, and as a result, the time for one-room operation becomes longer, and conversely, the time ton during which the compressor 25 is turned on becomes longer.
[0045]
As a result of the above, it is possible to reduce the time ton when the compressor 25 is turned on with respect to the cycle that is the sum of the time ton when the compressor 25 is turned on and the time toff when it is turned off. It can be performed.
(Example 2)
FIG. 2 will be described as another embodiment for explaining the effect of the present invention. The difference between FIG. 2 and FIG. 1 or FIG.
(1) The cooling operation capacity when all the rooms are operated simultaneously is shown in FIGS. 1 and 4 when the refrigerator 2A has a cooling capacity that can be lower than the lower limit value Td. On the other hand, FIG. 2 shows that the cooling capacity of the refrigerator 2A can be cooled to the specified temperature Ts when operated at the same time, but cannot be cooled to the lower limit value Td, and is cooled beyond the lower limit value Td only during one-chamber operation. Indicate when you can.
[0046]
(2) Therefore, only the horizontal time axis is scaled down, and the other conditions are the same.
[0047]
In FIG. 2, it is assumed that the cooling operation is performed simultaneously from the upper limit value Tu at time t20 as in FIG. As for the cooling rate, the chamber temperature (Tc, Tb, Ta) decreases in the order of the chambers 1C, 1B, and 1A, and the chamber temperature Tc of the chamber 1C reaches the specified temperature Ts at time t21. At this time t21, the room 1A having the highest room temperature is operated in one room, and the supply of the refrigerant 24 in the other rooms 1B and 1C is stopped. Since all the refrigerant 24 is supplied to the room 1A having the highest room temperature, the rate of temperature drop in the chamber is faster than the simultaneous cooling of multiple rooms, and the temperature (Ta) of one room (1A) is the lower temperature limit. Even if the temperature approaches Td, those that cannot be cooled to the lower limit Td by simultaneous cooling of a plurality of rooms can be cooled while maintaining the internal temperature drop rate.
[0048]
When one room 1A is operated and the internal temperature Ta reaches the lower limit Td at time t22, one room 1C having the highest room temperature at this time t22 is operated and the refrigerant 24 is supplied to the other rooms 1A and 1B. Stop. In the illustrated example, the order of the room is different from that of FIG. 1 and the room of single room operation, but the room 1C (room 1B in FIG. 1) in which the refrigerant 24 is concentrated has a lower rate of temperature in the cabinet, as in the case of the room 1A described above. It becomes faster and reaches the lower limit value Td at time t23 without much decrease in speed. At this time t23, the room 1B having the highest room temperature, that is, in the example shown in the figure, is the cooling of the three rooms, so the last remaining room 1B is operated, and the supply of the refrigerant 24 in the other rooms 1A and 1C is stopped. At time t24, the internal temperature Tc is made to reach the lower limit value Td.
[0049]
In this way, when all three rooms (1A, 1B, 1C) have reached the lower limit cooling temperature value Td at time t24, the compressor 25 is stopped and the cooling of all the rooms (1A, 1B, 1C,...) Is stopped. Stop the cooling operation. The compressor 25 continues until the temperature of any room reaches the upper limit Tu, and at time t25, the compressor 25 is started again to start simultaneous operation.
[0050]
In the illustrated example, the timing at which the supply of the refrigerant 24 to each room (1A, 1B, 1C) stops is shifted from t22, t23, t24, so there is a difference in the rise in the internal temperature after the compressor 25 is stopped. . In particular, the internal temperature Tb of the chamber 1B having an intermediate thermal time constant T1b is lower than that of the other two chambers 1A and 1C. In the illustrated example, simultaneous operation starts at time t25, and room 1C having a small thermal time constant T1c reaches the specified temperature Ts at time t26, enters single room operation of room 1A, and in the order of room 1B and room 1C 1 After entering the room operation, all three rooms (1A, 1B, 1C) reach the lower limit cooling temperature value Td at time t29d, the compressor 25 is stopped, and the cooling of all the rooms (1A, 1B, 1C) is stopped. Stop operation. In the following, while taking the cycle of simultaneous operation, one-room operation, and operation stop, the internal temperature of all the rooms (1A, 1B, 1C,...) Is controlled and maintained within a predetermined target temperature range. be able to.
[0051]
Under the conditions shown in FIG. 2, the refrigerator 2A cannot continuously reduce the internal temperature of the vending machine 1 to the lower limit value Td under the conditions shown in FIG. By providing the specified temperature Ts and performing the one-chamber operation, it is possible to stop the operation of the refrigerator 2A, and the energy-saving operation of the cooling compressor can be performed.
(Example 3)
Next, a control flowchart of the operation method according to the present invention will be described with reference to FIG. The description will be made assuming that the three chambers (1A, 1B, 1C) as described above have the same amount of influence of heat penetration from the outside, and that the thermal time constant of each chamber is in the condition of T1a>T1b> T1C. In this state, the temperature Tc of the chamber 1C decreases most quickly, and the temperature Ta of the chamber 1A decreases most slowly. In FIG. 3, the chamber temperature (Ta, Tb, Tc) of the three chambers (1A, 1B, 1C) is measured in step s1, and one of the three chambers (1A, 1B, 1C) is measured in step s2. However, it is determined whether or not the internal temperature has reached the specified temperature Ts, and the process returns to step s1 with the arrival No. In step s2, this flow is circulated and waited until it is detected that the inside temperature of any one of the rooms reaches the specified temperature Ts. When the internal temperature (Tc) of any one of the rooms (1C in the illustrated example) reaches the specified temperature Ts at step t2 at time t11 and detects Yes, the process proceeds to step s3.
[0052]
In step s3, the room 1A having the highest room temperature at this time is operated as one room, the supply of the refrigerant 24 to the other rooms 1B and 1C is shut off by the shutoff valve 22, and the process proceeds to step s4. In step s4, it is determined whether or not the room 1A, which shows the maximum room temperature at time t11 and is operating in one room, has reached the target temperature lower limit Td. If no, the process returns to step s3. This flow is circulated and waited until it is detected that the room 1A operating in one room reaches the target temperature lower limit Td.
[0053]
Then, when the temperature Ta of the room 1A reaches the lower limit value Td in step s4 at time t12, and the arrival Yes is detected, the process proceeds to step s5. In step s5, one room 1B showing the maximum room temperature at time t12 (that is, the room showing the intermediate room temperature at time t1) is operated, and the supply of the refrigerant 24 to the other rooms 1A and 1C is shut off. Shut off at 22 and proceed to step s6. In step s6, it is determined whether or not the room 1B, which exhibits the maximum room temperature at time t12 and is operating in one room, has reached the lower limit Td. If no, the process returns to step s5, and in step s6, this one-room operation is performed. Monitoring is performed until the room 1B that has been reached the lower limit Td and checked Yes.
[0054]
When the temperature Tb of the room 1B reaches the lower limit value Td at time t13 and the arrival Yes is detected, the process proceeds to step s7. In step s7, one room 1C showing the maximum room temperature at time t13 is operated, the supply of the refrigerant 24 to the other rooms 1A and 1B is shut off by the shut-off valve 22, and the process proceeds to step s8. In step s8, it is determined whether or not the room 1C, which exhibits the maximum room temperature at time t13 and is operating in one room, has reached the lower limit Td. If no, the process returns to step s7, and in step s8, this one-room operation is performed. The room 1C is monitored until reaching the lower limit Td and checking Yes.
[0055]
When the temperature Tc of the room 1C reaches the lower limit value Td at time t14 and the arrival Yes is detected, the process proceeds to step s9, where the operation of the compressor 25 is stopped, the cooling operation is stopped, and the process proceeds to step s10. . In step s10, it is determined whether the room temperature in any room has reached the upper limit value Tu. If no, the process returns to step s9, and in step s10, the room temperature in any room is the upper limit value. Monitoring is continued until Yes at Tu is checked, and when the temperature inside the room reaches the upper limit Tu at time t15 and detects Yes, the process proceeds to step s11, the compressor 25 is started, and all rooms 1A , 1B, 1C can be operated simultaneously, the process proceeds to step s1, and control can be continued.
Example 4
In the above description, according to the present invention, “the selection criterion for the room to be selected and cooled is to select the room having the highest temperature at the time of reaching the specified temperature Ts or the lower limit value Td”. The selection criterion of “selecting a room for cooling by selecting only one room is selected in the order of the room having the largest thermal time constant except for the room that has reached the lower limit value” can be adopted. If such a selection criterion is adopted, the problem of changing the order of the one-room operation that occurred at time t22d in FIG. 2 is solved, and the cooling is turned off in the order of the room with the larger thermal time constant. Therefore, all the rooms (1A, 1B, 1C,...) Can be made closer to the upper limit value Tu of the target temperature after the operation of the compressor 25 is stopped.
[0056]
For example, in the case of the vending machine 1, the quantity of products in each store of the vending machine 1 changes from time to time depending on the sales situation of the product, so the thermal time constant in each store changes. Therefore, it is preferable to measure this thermal time constant during the operation and sale of the vending machine 1 and adjust the selection criteria.
[0057]
As a method of measuring the thermal time constant and selecting the room in order of increasing thermal time constant, the chamber temperature (Ta, Tb, Tc, ...) is the lower limit for each room (1A, 1B, 1C, ...). After reaching the value Td, the temperature rise rate when the cooling is turned off, the temperature rise value for a predetermined time, or a temperature rise within a predetermined temperature range (for example, Td to (Tu-ΔT)) In the former two, the selection time is selected in ascending order of the temperature increase rate or temperature increase value, and in the latter, the selection order is selected in ascending order of the required time.
(Example 5)
In FIG. 6B, another energy-saving vending machine 3 using the energy-saving operation method of the cooling compressor according to the present invention has a plurality of rooms (1A, 1D, 2) controlled to a predetermined temperature range (Tu to Td). 1B, 1C, ・), and each room (1A, 1B, 1C, ・) is supplied with cold air 24A by the fan 29 and cooled by the evaporator 21B of the refrigerator 2B. The refrigerator 2B includes a compressor 25, a condenser 26, a dryer 27, a capillary tube or an expansion valve 28, an evaporator 21B, and each of these devices 21B, The piping 23 which connects 25-28 and comprises a circulation system and a ventilation system, and the refrigerant | coolant 24 which circulates in these apparatuses 25-28 can be provided and comprised.
[0058]
With this configuration, when the one-chamber cooling operation is performed, the total refrigeration capacity of the refrigerator 2B, that is, the entire amount cooled by the amount of heat absorbed by the refrigerant 24 as heat of vaporization that is absorbed and evaporated from the periphery of the evaporator 21B. Since the air can be used as cold air 24A to cool a selected room, the final cooling temperature is lower when operating in one room than in the final cooling temperature when operating all rooms simultaneously. Therefore, it is possible to cool with characteristics almost linearly toward the lower limit value Td of the temperature range. That is, the cooling rate can be improved and the ON time of the compressor 25 can be reduced.
[0059]
【The invention's effect】
As described above, according to the present invention, the following effects can be expected.
[0060]
(1) In the vicinity of the lower limit of the target temperature where it takes a relatively long time to lower the temperature, one room (cooling) is operated from the room with the highest temperature, thereby cooling efficiently by concentrating refrigerant or cold air. The operation time of the overall cooling compressor can be shortened. As a result, an energy saving operation method and an energy saving type vending machine for the cooling compressor can be provided.
[0061]
(2) In addition, by aligning the cooling timing of multiple rooms near the upper limit of the target temperature and operating them simultaneously, the temperature difference between the multiple rooms at the start of one-room operation is reduced, and all the multiple rooms are at the target temperature. The time from reaching the lower limit to turning off the cooling compressor can be shortened. As a result, an energy saving operation method and an energy saving type vending machine for the cooling compressor can be provided.
[0062]
(3) In addition, due to some circumstances, for example, due to abnormal temperature rise in summer, simultaneous cooling of multiple rooms cannot cool to the target temperature lower limit value, and even when the cooling compressor is in continuous operation, single room operation As a result, it is possible to efficiently cool by concentrating refrigerant or cold air, so that a period during which the cooling compressor can be turned off can be obtained. As a result, an energy-saving operation method for the cooling compressor and an energy-saving vending machine can be provided. it can.
[Brief description of the drawings]
FIG. 1 is an internal temperature characteristic diagram during cooling operation for explaining an energy saving operation method of a cooling compressor as one embodiment of the present invention.
[Fig. 2] Temperature characteristics of the chamber during cooling operation when the cooling capacity of the refrigerator is slightly insufficient
FIG. 3 is a control flowchart according to the operation method of the present invention.
FIG. 4 is a temperature characteristic diagram in the refrigerator during the cooling operation for explaining the energy saving operation method of the cooling compressor according to the prior art.
FIG. 5 is a control flowchart according to a conventional driving method.
6A and 6B are main part configuration diagrams of a vending machine according to the prior art and the present invention, wherein FIG. 6A is a configuration diagram in which an evaporator is provided for each room and refrigerant is supplied, and FIG. 6B is a supply of cold air for each room. Configuration diagram
[Explanation of symbols]
1, 3 Vending machine
1A, 1B, 1C room
2A, 2B refrigerator
21,21B evaporator
22 Shut-off valve
23 Piping
23B duct
24,24g, 24L refrigerant
24A cold air
25 Compressor
26 Condenser
27 Dryer
28 Expansion valve
29 fans
Ts Specified temperature
Tu upper limit
Td lower limit
ΔT temperature difference
t10 ~, t20 ~, t40 ~, ton, toff time

Claims (7)

Cooling compressor that operates and controls a refrigerator that performs cooling using a cycle of refrigerant evaporation and condensate liquefaction to cool a plurality of rooms, and maintains and controls the temperature of each room within a predetermined temperature range In the energy saving operation method of
In the cooling operation control for a plurality of rooms, an operation period composed of a simultaneous operation period, a one-room operation period, and an operation stop period is defined as one operation cycle, and a specified temperature and an upper limit value are set as control temperature parameters for the room to be controlled by cooling. and a lower limit value, when the temperature of any room of the plurality of chambers has reached the upper limit value, to start the compressor to cool a plurality of rooms at the same time, as a result of this simultaneous operation, one of the room when There reaching the specified temperature value, which was cooled to select only one room in accordance with the selection criteria established in advance, when the temperature of the first chamber operation result selected room reaches the lower limit, the chamber Cooling is stopped, one other room is sequentially selected according to the selection criteria, and one room operation is performed. After all the rooms are operated in one operation cycle, the temperature of the last selected room becomes the lower limit value. When it reaches The stop to stop cooling the entire room, energy-saving method of operating a cooling compressor, characterized in that. In the energy saving operation method of the cooling compressor according to claim 1,
The specified temperature is selected when a plurality of rooms are cooled at the same time, or when only one room is selected and cooled, and a temperature value that causes a difference in the cooling rate of the temperature in the room is selected. Energy-saving operation method for cooling compressors. In the energy saving operation method of the cooling compressor according to claim 1 or 2,
A method for energy saving operation of a cooling compressor, wherein the selection criterion for a room to be cooled by selecting only one room is to select a room having the highest temperature when reaching a specified temperature or a lower limit value. In the energy saving operation method of the cooling compressor according to claim 1 or 2,
A method for selecting a room for cooling by selecting only one room is selected in order of a room having a large thermal time constant, except for a room that has reached a lower limit value. In the energy saving operation method of the cooling compressor according to claim 4,
The room selection criteria for selecting and cooling only one room in the order of the room with the largest thermal time constant except for the room that has reached the lower limit value is one room operation, and after reaching the lower limit value, the cooling is stopped and the temperature rise characteristics of the room An energy-saving operation method characterized by ranking the selection. An energy-saving vending machine using the energy-saving operation method of the cooling compressor according to any one of claims 1 to 5,
Each room has a plurality of rooms controlled to a predetermined temperature range. Each room is supplied with a refrigerant from a refrigerator, and a shutoff valve that controls conduction / cutoff of the refrigerant, vaporizes the refrigerant, and cools the room. And an evaporator,
A refrigerator includes a compressor, a condenser, a dryer, a capillary tube or an expansion valve, and each of these devices constituting the cooling compressor according to any one of claims 1 to 5. A pipe that connects the shut-off valve and the evaporator in series, a pipe that connects the shut-off valve and the evaporator, and a pipe that constitutes a circulation system by further connecting the shut-off valve and the evaporator in another room in parallel, and these devices An energy-saving vending machine comprising a refrigerant circulating in the interior. An energy-saving vending machine using the energy-saving operation method of the cooling compressor according to any one of claims 1 to 5,
Each room has a plurality of rooms controlled to a predetermined temperature range, and each room receives supply of cold air cooled by an evaporator of the refrigerator, ON-OFF With a control valve to control,
A refrigerator includes a compressor, a condenser, a dryer, a capillary tube or an expansion valve, an evaporator, and each of these devices that constitute the cooling compressor according to any one of claims 1 to 5. Are connected to each other to form a circulation system, a refrigerant circulating in these devices, a fan that sucks and blows air cooled by an evaporator, and a duct that connects this cold air to a control valve in each room. An air-saving system characterized by comprising an air blowing system Vending machine.

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