WO2019208634A1

WO2019208634A1 - Hot/cold storage container

Info

Publication number: WO2019208634A1
Application number: PCT/JP2019/017438
Authority: WO
Inventors: 清水　拓也
Original assignee: サンデン・リテールシステム株式会社
Priority date: 2018-04-24
Filing date: 2019-04-24
Publication date: 2019-10-31
Also published as: JP2019190706A

Abstract

[Problem] To provide a hot/cold storage container capable of precise temperature management in which temperature changes are suppressed. [Solution] A hot/cold storage container (1) has an outer box (10) in the interior of which a chamber for storing an object is formed, and a first refrigeration circuit (21) for cooling the interior of the chamber. The first refrigeration circuit (31) is provided with, in a refrigerant circulation passage (33), at least an internal evaporator (21) that exchanges heat with the interior of the chamber, thereby evaporating a refrigerant, a compressor (35) for compressing the refrigerant, and an external evaporator (38) that is arranged in the circulation passage (33) on the upstream side of the compressor (35), and that exchanges heat with the outside of the chamber. The refrigerant flowing from the internal evaporator (21) passes through the external evaporator (38) and then returns to the compressor (35).

Description

Hot and cold storage

The present invention relates to a hot / cold storage for storing an article at a desired freezing / refrigeration temperature range to a temperature range.

The heating / cooling chamber that keeps the interior at an arbitrary temperature is provided with a heating device such as an electric heater and an evaporator of a cooling device, and the interior can be heated and cooled. In such a hot and cold storage, the temperature in the storage is detected, the operation of the heating device and the cooling device is controlled so as to become the set temperature, and the gradient operation for changing the interior to the set temperature or the storage Equilibrium operation is performed to maintain the inside at the set temperature.

For example, in Patent Document 1, the expansion mechanism of the cooling device includes a variable opening expansion mechanism, and the cooling device is operated continuously, while controlling the opening of the expansion mechanism and the output of the heating device to perform gradient operation and equilibrium operation. I do.

In Patent Document 2, ON / OFF control of the cooling device is performed so as to suppress deviation from the set temperature gradient during gradient operation.

JP-A-2-229556 Japanese Patent Laid-Open No. 3-218803

However, for example, in a temperature-controlled bath or a heating / cooling chamber used for research, precise temperature management is required to perform equilibrium operation in a slight temperature range and further suppress deviation from a set temperature gradient even in gradient operation. .

In such a temperature-controlled refrigerator that requires precise temperature management, the temperature control methods of Patent Document 1 and Patent Document 2 described above can maintain temperature accurately in a narrow range in equilibrium operation, or in gradient operation. It is difficult to suppress a deviation from the set temperature gradient and smoothly change the temperature.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a heating / cooling chamber capable of precise temperature management while suppressing a deviation from a set temperature.

In order to solve the above-described problem, the hot / cold storage according to the present invention includes a housing in which a storage room for storing articles is formed, and a first refrigeration cycle for cooling the inside of the storage room. The first refrigeration cycle includes a first internal evaporator that evaporates the refrigerant by at least exchanging heat with the interior of the warehouse in the refrigerant circulation path, and compresses the refrigerant. And a first outside evaporator disposed in the circulation path upstream of the compressor and exchanging heat with the outside of the warehouse to evaporate the refrigerant. It is characterized by.

Preferably, a heater for heating the inside of the storage room is provided.

Preferably, a second circulation evaporator configured to provide a refrigerant circulation path different from the first refrigeration cycle by at least a second internal evaporator that exchanges heat with the interior of the warehouse and evaporates the refrigerant. The refrigeration cycle is provided.

Preferably, the internal temperature detector for detecting the internal temperature of the storage room, and the first temperature in a temperature zone at least partially different from each other based on the internal temperature of the storage room detected by the internal temperature detector. And a control unit for operating the second refrigeration cycle.

Preferably, in the circulation path of the first refrigeration cycle, the external evaporator is disposed downstream of the first internal evaporator.

According to the present invention, since the first refrigeration cycle includes the internal evaporator and the external evaporator, the amount of refrigerant evaporated in the internal evaporator is suppressed, and the internal cooling capacity of the internal evaporator is suppressed. be able to. Further, by evaporating the refrigerant by the outside evaporator, it is possible to prevent the liquid refrigerant from returning to the compressor and to stably increase the temperature of the refrigerant flowing into the compressor. As a result, it is possible to perform precise temperature management such as maintaining the inside of the cabinet in a slight temperature range, suppressing deviation from the set temperature gradient, and smoothly changing the temperature.

It is a schematic perspective view of the hot and cold storage of one embodiment of the present invention. It is a block diagram of the 1st freezing circuit and the 2nd freezing circuit in the hot / cold storage of this embodiment. It is explanatory drawing which shows the setting point of the cooling capacity of each refrigeration cycle in the hot / cold storage of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The hot / cold storage according to the present embodiment is used as, for example, a thermostatic chamber or a medicine storage that requires precise temperature control.

FIG. 1 is a schematic perspective view of the hot and cold storage of the present invention.

The hot / cold storage 1 is composed of a storage section S arranged at the lower part and a machine part M arranged at the upper part.

The storage unit S includes an outer box 10 (housing) that is a rectangular parallelepiped housing having a front opening, and an outer door 11 for closing the front opening of the outer box 10. Each of the doors 11 has a structure filled with a heat insulating material.

The outer door 11 opens and closes the front opening of the outer box 10 by rotating around a hinge (not shown) attached to the front surface of the left or right side wall toward the outer box 10.

Inside the outer box 10, an inner box 12 (storage room) for storing articles is provided. Between the inner box 12 and the outer box 10, a duct 13 for circulating the air in the warehouse (in the storage unit S) is provided. The duct 13 is provided behind and above the inner box. The duct 13 above the inner box 12 has an electric heater 20 (heater) as a heating device for heating the inside of the box and a cooling device for cooling the inside of the box, which will be described later. The internal evaporator 21 (first internal evaporator, second internal evaporator) and fan 22 of the first freezing circuit 31 and the second freezing circuit 32 are provided. The duct 13 communicates the opening 23 at the lower end of the rear part of the inner box 12 and the opening 24 at the upper front end. In the duct 13 above the inner box 12, an internal evaporator 21, a fan 22, and an electric heater 20 are arranged in this order from the rear to the front. By the operation of the fan 22, the air in the duct 13 passes through the internal evaporator 21 and the electric heater 20, is reflected on the inner wall surface of the outer door 11, and flows into the inner box 12 from the opening 24. Then, the air in the inner box 12 is sucked into the duct 13 through the opening 23 and returns to the internal evaporator 21 to circulate in the storage unit S.

Further, on the front surface of the machine part M, an operating device 30 for setting a target temperature reached in the storage is provided.

FIG. 2 is a configuration diagram of the first refrigeration circuit 31 (first refrigeration cycle) and the second refrigeration circuit 32 (second refrigeration cycle) in the hot / cold storage 1.

The hot / cold storage 1 of the present embodiment includes a first refrigeration circuit 31 and a second refrigeration circuit 32 as a cooling device for cooling the inside of the storage.

The first refrigeration circuit 31 has a refrigerant circulation path 33, and the second refrigeration circuit 32 has a refrigerant circulation path 34. The circulation path 33 and the circulation path 34 are configured independently of each other. As the refrigerant, for example, both the first refrigeration circuit 31 and the second refrigeration circuit 32 use HFC-134a.

In the circulation path 33 of the first refrigeration circuit 31, the compressor 35, the condenser 36, the electronic expansion valve 37, the internal evaporator 21 (first internal evaporator), An outer evaporator 38 is provided.

On the other hand, in the circulation path 34 of the second refrigeration circuit 32, the compressor 40, the condenser 41, the electronic expansion valve 42, and the internal evaporator 21 (second internal evaporator) are sequentially arranged in the refrigerant flow direction. It has.

Since each of the

compressors

35 and 40, the

condensers

36 and 41, the

electronic expansion valves

37 and 42, and the internal evaporator 21 in each

refrigeration circuit

31 and 32 is a known configuration, a detailed description of the structure and function is provided. Is omitted.

The first refrigeration circuit 31 is provided with a hot gas defrosting circuit 45. The hot gas defrosting circuit 45 includes a flow path switching electromagnetic valve 46 disposed in the circulation path 33 between the compressor 35 and the condenser 36, a branch from the electromagnetic valve 46, and an electronic expansion valve 37 and a warehouse. The communication path 47 communicates with the circulation path 33 between the inner evaporator 21 and the inner evaporator 21.

The solenoid valve 46 is switched so that all the refrigerant discharged from the compressor 35 flows into the condenser 36 at normal times. In the hot gas defrosting circuit 45, for example, the user operates the electromagnetic valve 46 by operating the operation device 30, and guides the refrigerant that has been compressed by the compressor 35 and has reached a high temperature to the internal evaporator 21 through the communication path 47. Thus, the internal evaporator 21 is heated to remove frost in the internal storage.

The

compressors

35 and 40, the

condensers

36 and 41, the

electronic expansion valves

37 and 42, and the outside evaporator 38 are disposed in the machine part M. The internal evaporator 21 is arranged inside the outer box 10, that is, in the storage unit S as described above.

In the internal evaporator 21, the

refrigerant circulation paths

33 and 34 are disposed independently of each other. However, all or part of other components such as fins are made common to the first refrigeration circuit. 31 and the 2nd freezing circuit 32 are comprised integrally so that use is possible.

The external evaporator 38 is an evaporator having a smaller capacity than the internal evaporator 21.

The external evaporator 38 exchanges heat between the refrigerant that has passed through the internal evaporator 21 and the outside air, and evaporates the refrigerant that could not be evaporated in the internal evaporator 21. Thereby, the temperature of the refrigerant returning to the compressor 35 can be stably increased, and the suction temperature of the compressor 35 can be stabilized.

That is, the first refrigeration circuit 31 can be stably operated even with a small cooling capacity as compared with the second refrigeration circuit 32 that does not have the external evaporator 38.

Further, for each of the first refrigeration circuit 31 and the second refrigeration circuit 32, the inlet of the internal evaporator 21 is provided with an evaporation temperature sensor (not shown) that detects the refrigerant temperature as the evaporation temperature of the refrigerant. The outlet of the evaporator 21 is provided with a superheat degree sensor (not shown) that detects the refrigerant temperature as the superheat degree of the refrigerant.

The inner box 12 of the hot / cold refrigerator 1 is provided with an internal temperature sensor 51 (internal temperature detector) for detecting the internal temperature, and the machine part M is provided with an external air temperature sensor 52 for detecting the external temperature. . And in the control unit 50 (control part) with which the machine part M was equipped, based on the inside temperature, the outside temperature, the evaporation temperature, the degree of superheat, the target set temperature set by the operating device 30, etc., the

electronic expansion valve

37, 42, the electric heater 20, the fan 22, and the like are controlled to perform cooling control by the first refrigeration circuit 31, cooling control by the second refrigeration circuit 32, and temperature rise control by the electric heater 20.

In the hot / cold storage 1 of the first embodiment, the first refrigeration circuit 31 and the second refrigeration circuit 32 are set to operate in substantially the same internal temperature range. Basically, the first refrigeration circuit 31 is continuously operated at all times. For example, when the internal cooling temperature is significantly higher than the target temperature and the required cooling capacity is large, the first refrigeration circuit 31 and the second refrigeration circuit 32 are connected. Operate.

As described above, in the hot / cold storage 1 of the first embodiment, since the first refrigeration circuit 31 includes the internal evaporator 21 and the external evaporator 38, the heat exchange of the refrigerant in the internal evaporator 21 is performed. The amount can be reduced. Therefore, when the internal temperature is close to the target temperature, cooling of the internal space by the internal evaporator 21 can be suppressed even when the first refrigeration circuit 31 is continuously operated, and stable internal temperature control is achieved. It can be performed.

Even if the refrigerant is not sufficiently evaporated in the internal evaporator 21, the refrigerant can be evaporated in the external evaporator 38, so that the liquid refrigerant can be prevented from returning to the compressor 35. Thereby, the compressor 35 can be protected. Further, the temperature of the refrigerant flowing into the compressor 35 can be stably increased, and the first refrigeration circuit 31 can be stably operated.

Therefore, the first refrigeration circuit 31 performs precise temperature management such as maintaining the inside of the cabinet in a narrow temperature range, suppressing deviation from the set temperature gradient, and smoothly changing the temperature. A suitable hot / cold storage 1 can be obtained.

Furthermore, since the hot / cold storage 1 is provided with the 2nd freezing circuit 32, the amount of heat exchange in the internal evaporator 21 is increased by operating the 2nd freezing circuit 32 with the 1st freezing circuit 31. be able to. Thereby, for example, when the internal temperature is high, it is possible to secure a large cooling capacity and to rapidly decrease the internal temperature.

Moreover, since the electric heater 20 is provided, the air circulating in the warehouse can be heated with a desired amount of heat with good responsiveness. Thereby, the inside of a store | warehouse | chamber can be heated rather than external temperature, For example, it can utilize as a thermostat used as a thermostat etc. which maintain the inside of a store | warehouse | chamber at the temperature of a freezing / refrigeration temperature zone.

In addition, by using the electric heater 20 when cooling, the temperature of the interior can be controlled more precisely by controlling the electric heater 20 in response to a temperature change in the interior quickly.

The first refrigeration circuit 31 includes an outside evaporator 38 and can be operated with a low cooling performance inside the warehouse. Therefore, the electric heater 20 is used for cooling as described above. However, the power consumption of the electric heater 20 can be suppressed.

In addition, in the said embodiment, although the internal evaporator 21 and the external evaporator 38 of the 1st freezing circuit 31 are arrange | positioned in series with the circulation path 33, you may arrange | position in parallel. By arranging in parallel, the refrigerant flowing out of the internal evaporator 21 returns to the compressor 35 without passing through the external evaporator 38. Therefore, although the protection performance of the compressor 35 is inferior to that arranged in series, the amount of refrigerant passing through the internal evaporator 21 can be reduced to suppress the internal cooling performance.

When the internal evaporator 21 and the external evaporator 38 are provided in parallel, the electronic expansion valve 37 may be provided for each. Thus, the amount of refrigerant flowing into the internal evaporator 21 and the amount of refrigerant flowing into the external evaporator 38 can be controlled by controlling the two electronic expansion valves 37. For example, when the difference between the internal temperature and the target temperature that is set as appropriate is large, the amount of refrigerant flowing into the external evaporator 38 is suppressed, the internal cooling performance is ensured, and the internal temperature and the target temperature are If the difference is small, the amount of refrigerant flowing into the external evaporator 38 can be increased to reduce the cooling performance in the storage and stabilize the slight cooling.

Further, the hot gas defrosting circuit 45 may be provided in the second refrigeration circuit 32 in the same manner as the first refrigeration circuit 31. Thereby, the internal evaporator 21 can be heated by both the 1st freezing circuit 31 and the 2nd freezing circuit 32, and the defrosting function in a warehouse can be improved.

Next, a second embodiment in which the first refrigeration circuit 31 and the second refrigeration circuit 32 are switched over based on the internal temperature will be described.

In the second embodiment, the first refrigeration circuit 31 has the same configuration as that of the first embodiment. However, the second refrigeration circuit 32 is similar to the first refrigeration circuit 31 and is connected to the outside evaporator 38. Is provided.

The control unit 50 switches the operation of the first refrigeration circuit 31 and the second refrigeration circuit 32 based on the internal temperature.

FIG. 3 is a graph showing a setting example of the cooling capacity of the first refrigeration circuit 31 and the second refrigeration circuit 32. FIG. 3 shows changes in the cooling capacity of the first refrigeration circuit 31 and the second refrigeration circuit 32 with respect to the internal temperature.

As shown in FIG. 3, the cooling capacity of the first refrigeration circuit 31 and the cooling capacity of the second refrigeration circuit 32 are added to obtain the required cooling capacity. The cooling capacity of the second refrigeration circuit 32 is adjusted.

When the internal temperature is 8 ° C. or lower, the cooling capacity of the first refrigeration circuit 31 is 100%, the cooling capacity of the second refrigeration circuit 32 is 0%, and only the first refrigeration circuit 31 is movable.

Since the cooling capacity of the first refrigeration circuit 31 is controlled by the internal temperature, the degree of superheat of the refrigerant, and the evaporation temperature, 100% of the cooling capacity at the internal temperature of 8 ° C. or less in FIG. This is not the maximum cooling capacity of the refrigeration circuit 31 but the cooling capacity required based on the internal temperature or the like.

When the internal temperature is 12 ° C. or higher, the cooling capacity of the first refrigeration circuit 31 is 0%, the cooling capacity of the second refrigeration circuit 32 is 100%, and only the second refrigeration circuit 32 is movable.

Further, since the cooling capacity of the second refrigeration circuit 32 is also controlled by the internal temperature or the like, 100% of the cooling capacity at the internal temperature of 12 ° C. or higher in FIG. It is not the capacity but the cooling capacity required based on the internal temperature.

For example, when the maximum cooling capacity of the first refrigeration circuit 31 = the maximum cooling capacity of the second refrigeration circuit 32 = 1 kW, and the cooling capacity required when the internal temperature is 10 ° C. is 1 kW, The cooling capacity of the first refrigeration circuit 31 = the cooling capacity of the second refrigeration circuit 32 = 0.5 kW. When the cooling capacity required when the internal temperature is 10 ° C. is 0.5 kW, the cooling capacity of the first refrigeration circuit 31 = the cooling capacity of the second refrigeration circuit 32 = 0.25 kW.

When the cooling capacity required when the internal temperature is 9 ° C. is 1 kW, the cooling capacity of the first refrigeration circuit 31 is set to 0.75 kW, and the cooling capacity of the second refrigeration circuit 32 is set to 0.25 kW. .

As described above, in the second embodiment, when the internal temperature is 8 ° C. or lower, only the first refrigeration circuit 31 is operated, and when the internal temperature is 12 ° C. or higher, the second refrigeration circuit 32 is operated. Operate only. In the overlapping temperature range of 8 ° C. to 12 ° C., the first refrigeration circuit 31 and the second refrigeration circuit 32 operate while adjusting their capacities. As shown in FIG. 3, the ratio between the cooling capacity of the first refrigeration circuit 31 and the cooling capacity of the second refrigeration circuit 32 is continuously smooth with respect to the temperature change in the cabinet at 8 ° C. to 12 ° C. Therefore, the overall cooling capacity in the cabinet can also be changed smoothly.

Thus, in the second embodiment, the first refrigeration circuit 31 and the second refrigeration circuit 32 are operated in suitable temperature ranges at least partially different from each other. Since both the first refrigeration circuit 31 and the second refrigeration circuit 32 are provided with the outside evaporator 38, the cooling performance can be stably operated at low temperature in any different temperature range, and the precise Temperature control is possible.

In the second embodiment, only the first refrigeration circuit 31 includes the hot gas defrost circuit 45. The first refrigeration circuit 31 operates in the freezing temperature zone of water as described above, for example, so that water condensed on the fins of the internal evaporator 21 is frozen, but the second refrigeration circuit 32 is in the freezing temperature zone of water. Since it does not operate, it does not freeze even if condensation is formed on the fins of the internal evaporator 21. Therefore, the hot gas defrosting circuit 45 is not required according to the operating temperature zone, and the number of parts can be reduced.

In the second embodiment, the refrigerant of the first refrigeration circuit 31 and the refrigerant of the second refrigeration circuit 32 may be different from each other. For example, HFC-404A may be used as the refrigerant in the first refrigeration circuit 31, and HFO-1234YF may be used as the refrigerant in the second refrigeration circuit 32. As described above, a suitable refrigerant is used in each of the temperature zone of 12 ° C. or less in the cabinet using the first refrigeration circuit 31 and the temperature zone of 8 ° C. or more in the cabinet using the second refrigeration circuit 32. Thus, efficiency can be improved or stable cooling can be achieved.

In the second embodiment, the refrigerant amount of the first refrigeration circuit 31 and the refrigerant amount of the second refrigeration circuit 32 may be different. As described above, when the first refrigeration circuit 31 is used at a temperature zone of 12 ° C. or lower and the second refrigeration circuit 32 is used at a temperature zone of 8 ° C. or higher, the first refrigeration circuit is used. Since the internal temperature has already decreased at 31, the amount of refrigerant in the first refrigeration circuit 31 may be made smaller than the amount of refrigerant in the second refrigeration circuit 32. Thereby, since the cooling capacity of the 1st freezing circuit 31 falls, it can be set as the freezing circuit suitable for balance control which maintains at target temperature with a slight temperature change.

In the first embodiment and the second embodiment, the external evaporator 38 is disposed on the downstream side of the internal evaporator 21 in the circulation path 33 of the first refrigeration circuit 31. An external evaporator 38 may be arranged on the upstream side of the inner evaporator 21. In this case, the electronic expansion valve 37 may be disposed between the outside evaporator 38 and the condenser 36, between the outside evaporator 38 and the condenser 36, and between the outside evaporator 38 and the warehouse. You may arrange | position between the inner evaporators 21, respectively. Similarly, in the second refrigeration circuit 32 of the second embodiment, the external evaporator 38 may be arranged on the upstream side of the internal evaporator 21.

In addition, the hot and cold storage of the present invention is widely applied not only to a thermostatic bath and a medicine storage as in the above embodiment, but also to a hot and cold storage that requires precise temperature control such as aging of environmental test equipment and meat. Can do.

1 Hot and cold storage 10 Outer box (housing)
20 Electric heater (heater)
21 Internal evaporator (first internal evaporator, second internal evaporator)
31 First refrigeration circuit (first refrigeration cycle)
32 Second refrigeration circuit (second refrigeration cycle)
33, 34 Circulation path 35 Compressor 38 External evaporator 50 Control unit (control unit)
51 Internal temperature sensor (Internal temperature detector)

Claims

A housing in which a storage room for storing articles is formed;
A first refrigeration cycle for cooling the interior of the storage room,
The first refrigeration cycle includes, in the refrigerant circulation path, at least a first internal evaporator that exchanges heat with the interior of the storage chamber to evaporate the refrigerant, a compressor that compresses the refrigerant, A hot / cold refrigerator provided with an external evaporator disposed in the circulation path on the upstream side of the compressor and exchanging heat with the outside of the storage chamber to evaporate the refrigerant.
The heating / cooling chamber according to claim 1, further comprising a heater for heating the inside of the storage room.
A second refrigeration cycle comprising a refrigerant circulation path different from that of the first refrigeration cycle, and at least a second internal evaporator that evaporates the refrigerant by exchanging heat with the interior of the warehouse. The hot / cold storage according to claim 1 or 2, characterized by comprising:
An internal temperature detector for detecting the internal temperature of the storage room;
A controller that operates the first refrigeration cycle and the second refrigeration cycle in a temperature zone at least partially different from each other based on the internal temperature of the storage room detected by the internal temperature detector. The hot and cold storage according to claim 3.
5. The apparatus according to claim 1, wherein the external evaporator is disposed downstream of the first internal evaporator in the circulation path of the first refrigeration cycle. 6. Hot and cold storage.