JP2019113209A - Cooler using air refrigerant cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device using an air-refrigerant cycle capable of lengthening a cooling operation time. SOLUTION: A compressor C that compresses air recovered from a cooled chamber 2, heat exchangers 3 and 4 that cools the air compressed by the compressor C, and air that is cooled by the heat exchangers 3 and 4. A cooling device 1 using an air-refrigerant cycle, which includes: an expander E for expanding the air conditioner; and a defroster 6 for collecting moisture contained in the air flowing from the expander E into the cooled chamber 2 as frost. The defrosting device 6 includes flow paths 60a and 60b branching from the expander E into a plurality of paths, and defrosters 61 and 62 that are respectively connected to the defroster 61 and the flow path 60a to which the defrosters 61 and 62 are connected. , 60b, when one of the flow paths is blocked, the other flow path is communicated with the cooled chamber 2. [Selection diagram] Figure 1

Description

  The present invention relates to a cooling device using an air refrigerant cycle.

  DESCRIPTION OF RELATED ART The cooling device applied to to-be-cooled rooms, such as a warehouse, in order to preserve | save various raw materials, processed products, fresh food etc. is known widely. In such a cooling device, a refrigerant such as fluorocarbon was conventionally used, but in recent years, a cooling device using an air refrigerant is required from the viewpoint of environmental protection.

  As a cooling device using an air refrigerant, for example, as disclosed in Patent Document 1, a compressor that compresses air taken into a pipe path from a chamber to be cooled, and high-pressure high-temperature air compressed by the compressor are cooled Heat exchanger, and an expander for expanding high-pressure low-temperature air cooled by the heat exchanger to a low pressure (approximately atmospheric pressure), and a cryogenic chamber expanded by There is a cooling system using an open air refrigerant cycle that supplies

  In a cooling device using such an open air refrigerant cycle, the outside air (atmosphere) flowing in from the inlet / outlet of the chamber to be cooled and the breath of the worker working in the chamber may be mixed. Since the amount of water contained in the air in the cooling device changes due to the outside air or exhalation, the water in the air coagulates in the piping path of the cooling device, particularly on the downstream side of the expander having a low temperature, and frost is formed. In some cases, extremely low temperature air containing a large amount of frost is blown into the chamber to be cooled. Then, the cooling device of patent document 1 has provided the defroster which collects the water | moisture content contained in air of ultra-low temperature between an expander and a to-be-cooled room.

WO 2006/011297 (Page 7, FIG. 1)

  In the cooling device of Patent Document 1, since the defroster is provided on the downstream side of the expander that is likely to generate frost, the water in the low-pressure low-temperature air can be efficiently collected to provide a cooled room Although it is possible to suppress the blowing out of the frost, it is easy for the defroster to be clogged because the amount of the frost collected in the defroster is large, and the frost attached to the defroster There was a need to perform defrost operation frequently to eliminate it. Since the cooling operation is stopped when performing the defrosting operation, there is a possibility that the room to be cooled can not be stably cooled to the desired temperature, and the room temperature may rise.

  The present invention has been made in view of such problems, and it is an object of the present invention to provide a cooling device using an air refrigerant cycle that can extend the cooling operation time.

In order to solve the above-mentioned subject, a cooling device using an air refrigerant cycle of the present invention is:
From the compressor for compressing the air recovered from the cooled chamber, the heat exchanger for cooling the air compressed by the compressor, the expander for expanding the air cooled by the heat exchanger, and the expander A cooling device using an air refrigerant cycle comprising: a defrosting device for collecting as a frost the water contained in the air flowing into the room to be cooled;
The defrosting apparatus includes a flow path branched from the expander into a plurality, and a defroster connected to at least two flow paths of the plurality of flow paths, respectively.
When one of the flow paths to which the defroster is connected is shut off, the other flow path is configured to communicate with the cooling chamber.
According to this feature, when one of the flow paths is blocked and the defroster connected to the flow path is put into the defrosting operation state, the other defroster communicates with the chamber to be cooled. The operation can be performed continuously.

The one flow path and the other flow path to which the defroster is connected are characterized in that at least one valve is provided on the upstream side or the downstream side of each of the one flow path and the other flow path.
According to this feature, it is possible to easily control the normal state or the defrosting operation state of each defroster.

The valve is characterized in that it is a switching valve that controls the one flow passage and the other flow passage.
According to this feature, when one of the defrosters is in the defrosting operation state, the other defroster reliably communicates with the chamber to be cooled.

On the downstream side of the defrosters respectively connected to the at least two flow paths, there is provided a communication passage for communicating the defrosters with each other, and the communication passages are in communication and non-communication states. It is characterized in that it can be switched.
According to this feature, by setting the communication passage in the communication state, it is possible to precool one defroster for which the defrost operation has been completed by the air passing through the other defroster.

The to-be-cooled chamber is provided in the middle of the communication passage.
According to this feature, since the air after passing through the chamber to be cooled precools the defroster after the defrosting operation, there is no influence on the temperature of the air in the chamber to be cooled.

The defrosters respectively connected to the at least two flow paths are each provided with a bypass passage communicating with the compressor, and the bypass passage can be switched between the communicating state and the non-communicating state It is characterized by
According to this feature, by setting the bypass passage in the communication state, it is possible to discharge the air after precooling the defroster to the compressor without returning it to the cooled chamber side.

A flow path for transferring heat between the compressor and the heat exchanger is characterized by extending to the vicinity of the defroster.
According to this feature, since the defroster can be warmed using the high temperature air compressed by the compressor, it is not necessary to separately prepare a heater or the like, and the structure of the cooling device can be simplified.

In the cooling device using the air refrigerant cycle in the example of the present invention, it is a figure showing the cooling operation mode which performs defrost of a 2nd defroster in parallel with the dehumidification of the air refrigerant with a 1st defroster. (A) is a plane view cross section schematic diagram showing a defroster, and (b) is a side view section schematic diagram showing a defroster. (A), (b) is a time-chart figure which shows a mutually different cooling operation cycle. In the cooling device using an air refrigerant cycle, it is a figure showing the cooling operation mode which performs precooling of the 2nd defroster in parallel with the dehumidification of the air refrigerant with the 1st defroster. In the cooling device using an air refrigerant cycle, it is a figure showing the cooling operation mode which carries out dehumidification of the air refrigerant with the 2nd defroster in parallel with the defrost of the 1st defroster. In the cooling device using an air refrigerant cycle, it is a figure showing the cooling operation mode which carries out dehumidification of the air refrigerant with the 2nd defroster in parallel with the precooling of the 1st defroster. In another form of the cooling device using an air refrigerant cycle, it is a figure which shows the cooling operation aspect which dehumidifies an air refrigerant with a 1st defroster and a 2nd defroster.

  EMBODIMENT OF THE INVENTION The form for implementing the cooling device using the air refrigerant | coolant cycle which concerns on this invention is demonstrated below based on an Example.

  A cooling device using an air refrigerant cycle according to an embodiment will be described with reference to FIGS. 1 to 7.

  As shown in FIG. 1, the cooling device 1 in the present embodiment is a piping system connected to a room to be cooled 2 which is a space for storing objects to be cooled such as various materials, processed products, and fresh food products. is there. The cooling device 1 is a cooling device using an air refrigerant cycle that sucks in air from the cooled chamber 2 and cools the air in the cooling device 1 and then reduces the air into the cooled chamber 2.

  More specifically, since the cooling chamber 2 has an inlet / outlet through which an operator can enter and exit from the outside, the inside of the cooling chamber 2 operates in the outside air (atmosphere) flowing in from the inlet / outlet and the cooling chamber. Worker's breath is inevitably mixed. That is, it is a cooling device using a so-called open type air refrigerant cycle in which the amount of water contained in the air taken into the cooling device 1 changes. The cooling device 1 can be applied to refrigeration, refrigeration, air conditioning and cooling, etc., depending on the difference in temperature and pressure of the system, and is more preferably applied to a refrigeration system in an ultra-low temperature range of -55.degree.

  Next, the structure of the cooling device 1 will be described. The cooling device 1 includes a compressor C (compressor), a third heat exchanger 5 serving also as a part of the defrosting flow path 50, a first heat exchanger 3, a second heat exchanger 4, and an expansion turbine E (expansion machine). The defroster 6 mainly includes a first defroster 61 and a second defroster 62, and these devices are connected in a communicable state via a pipe and a valve as described later.

  Specifically, the high temperature side flow passage 5a of the third heat exchanger 5 is connected to the downstream side of the compressor C through the pipe 7a. The high temperature side pipe 3 a of the first heat exchanger 3 is connected to the downstream side of the high temperature side flow passage 5 a of the third heat exchanger 5 via the pipe 7 b. The high temperature side piping 4 a of the second heat exchanger 4 is connected to the downstream side of the high temperature side piping 3 a of the first heat exchanger 3 via the piping 7 c, and the high temperature side piping 4 a of the second heat exchanger 4 is The expansion turbine E is connected downstream of the expansion turbine E via the pipe 7e, and the defroster 6 is connected downstream of the expansion turbine E via the pipe 7e. An inlet valve 8, which is a three-way switching valve, is connected to the downstream side of the defroster 6, and the downstream side of the inlet valve 8 is connected to one vent (not shown) in the cooled chamber 2 via a pipe 7f. It is connected. An outlet valve 9 which is a three-way switching valve is connected to the other vent (not shown) in the cooled chamber 2 through a pipe 7g, and a second side of the outlet valve 9 is connected via a pipe 7h. The low temperature side pipe 4b of the heat exchanger 4 is connected, and the downstream side of the low temperature side pipe 4b of the second heat exchanger 4 is connected to the compressor C via a pipe 7j. The outlet valve 9 is connected to the defroster 6 through a bypass pipe 7n, and the pipe 7h is connected to the defroster 6 through branched bypass pipes 7k and 7m. The defrosting device 6 will be described in detail later.

  The compressor C and the expansion turbine E are driven by a motor 10. The motor 10 includes a pair of coaxially extending drive shafts 10a and 10b, to each of which a compressor C and an expansion turbine E are connected, and the expansion turbine E generated by high pressure air on the upstream side of the expansion turbine E The rotational power is transmitted to the drive shaft 10a of the compressor C via the drive shaft 10b, whereby power recovery is performed.

  Further, the motor 10 is connected to an air-cooling circulation channel 12 in which air is circulated by the air-cooling fan F1, and is cooled by the fan F1 and the air-cooling circulation channel 12. Further, a radiator 13 that exchanges heat with air in the air cooling circulation channel 12 is connected to the air cooling circulation channel 12.

  The third heat exchanger 5 is an air-cooled heat exchanger in this embodiment, and the high temperature side flow passage 5a through which air flows from the compressor C to the first heat exchanger 3 and the high temperature side flow passage 5a are separate systems The air flowing through the high temperature side flow passage 5a by heat exchange between the high temperature side flow passage 5a and the low temperature side flow passage 5b. While cooling can be performed, the outside air flowing through the low temperature side flow passage 5b which is a part of the defrosting flow passage 50 can be heated. The high-temperature side flow passage 5a and the low-temperature side flow passage 5b referred to here are the high-temperature side and the low-temperature side when comparing the air flowing inside the two pipes performing heat exchange in the third heat exchanger 5. .

  In the present embodiment, the first heat exchanger 3 is a water-cooled heat exchanger, and the high-temperature side piping 3a through which air flows from the third heat exchanger 5 to the second heat exchanger 4 and the high-temperature side piping 3a are A low-temperature side pipe 3b, which is a separate system, through which cooling water circulates, and heat exchange between the high-temperature side pipe 3a and the low-temperature side pipe 3b cools the air flowing in the high-temperature side pipe 3a. It can be done. The high-temperature side pipe 3a and the low-temperature side pipe 3b referred to here are the high-temperature side and the low-temperature side when the air flowing inside the two pipes performing heat exchange in the first heat exchanger 3 is compared.

  The second heat exchanger 4 includes a high temperature side pipe 4 a through which the air cooled by the first heat exchanger 3 flows, and a low temperature side pipe 4 b through which the air flows from the cooled chamber 2 to the compressor C By exchanging heat between the side piping 4a and the low temperature side piping 4b, the air flowing through the high temperature side piping 4a can be cooled. The high-temperature side pipe 4 a and the low-temperature side pipe 4 b referred to here are the high-temperature side and the low-temperature side when the air flowing inside the two pipes performing heat exchange in the second heat exchanger 4 is compared.

  As illustrated in FIG. 1, the defrosting device 6 includes a first switching valve 63 which is a three-way switching valve, and pipes 60 a and 60 b (flow paths) disposed in parallel via the first switching valve 63. The first defroster 61 connected through the pipe 60a, the second defroster 62 connected through the pipe 60b, the pipe 60c connected downstream of the first defroster 61, and 2 mainly includes a pipe 60 d connected to the downstream side of the defroster 62. The pipe 7 e is connected to the upstream side of the first switching valve 63, and the inlet valve 8 is connected to the downstream side of the pipes 60 c and 60 d. The pipes 60c and 60d have branched pipes 60e and 60f, and the pipes 60e and 60f are connected to the downstream side of the second switching valve 64 which is a three-way switching valve, respectively. The upstream side is connected to the outlet valve 9 via a bypass pipe 7n. Furthermore, since the pipes 60a and 60b have branched bypass pipes 60k and 60m and are connected to the bypass pipes 7k and 7m through the gate valves 65 and 66, the bypass pipes 7k and 60k and the gate valve 65 are used. A first bypass passage 71 communicating the first defroster 61 with the compressor C, and a second bypass passage which can communicate the compressor C with the first defroster 61 by the bypass pipes 7m and 60m and the dividing valve 66; 72 are formed. Specifically, a communication passage connecting the first defroster 61 and the second defroster 62 is formed by the pipes 60 c and 60 d connected via the inlet valve 8. It can be switched to the disconnected state. A communication passage communicating with the second defroster 62 is formed by the pipes 60e and 60f branched from the pipes 60c and 60d and connected via the second switching valve 64. The second switching valve 64 Thus, it is possible to switch between the communication state and the non-communication state. Furthermore, the first defroster 61 is connected by the pipes 60c, 60d, 60e, 60f connected via the inlet valve 8, the cooled chamber 2, the outlet valve 9 and the second switching valve 64, the pipes 7f, 7g and the bypass pipe 7n. A communication passage connecting the second defroster 62 and the second defroster 62 is formed, and can be switched between the communication state and the non-communication state by the inlet valve 8, the outlet valve 9 and the second switching valve 64. That is, a plurality of communication paths are formed, and switching is possible by operating the inlet valve 8, the outlet valve 9 and the second switching valve 64.

  Next, the first defroster 61 will be described, and the description of the second defroster 62 which is substantially the same as that of the first defroster 61 will be omitted. As shown in FIGS. 2 (a) and 2 (b), the first defroster 61 has a box-shaped case 61a connecting the pipe 60a and the pipe 60c, and the case 61a and the space on the pipe 60a side and the pipe 60c. It is comprised from the mesh member 61b divided into the space of the side. As described later, when the air flowing from the expansion turbine E to the pipe 7f through the pipe 7e passes through the mesh member 61b, the water contained in the air is adsorbed as a frost on the mesh member 61b. .

  Further, as shown in FIG. 1, around the first defroster 61, detection means 14 for detecting clogging of the first defroster 61 is provided. The detection means 14 includes a pressure gauge 14a connected to the pipe 60a on the upstream side of the mesh member 61b of the first defroster 61, and a pressure gauge 14b connected to the pipe 60c on the downstream side of the mesh member 61b. , And a differential pressure gauge 14c that measures a differential pressure with the pressure gauges 14a and 14b, and when the differential pressure measured by the differential pressure gauge 14c becomes a predetermined threshold or more, the first defroster 61 Detects as clogged. The cooling device 1 is configured to switch the cooling operation mode of the cooling device 1 in order to perform defrosting of the first defroster 61 when the detection means 14 detects clogging of the first defroster 61. . The cooling operation of the cooling device 1 including the defrosting of the first defroster 61 and the switching of the cooling operation mode of the cooling device 1 will be described in detail later.

  In addition, about description of detection means 14 '(refer FIG. 5, FIG. 6) by the side of 2nd defroster 62, pressure gauge 14a', 14b 'is substantially the same as detection means 14 by the side of 1st defroster 61. And the differential pressure gauge 14c 'and detects clogging of the second defroster 62, and hence the description thereof is omitted.

  Here, the configuration of the defrosting channel 50 will be described. The defrosting flow path 50 is a flow path for defrosting (defrosting) the frost adhering to the defrosting device 6 by heating. If it explains in full detail, piping 50d which has fan F2 is connected to the upper stream side of low temperature side channel 5b of the 3rd heat exchanger 5, three-way switching is carried out via piping 50c to the downstream of low temperature side channel 5b. A first switching valve 53 which is a valve is connected. On the downstream side of the first switching valve 53, a pipe 50a for discharging the heat-exchanged outside air to the outside of the cooling device 1 is connected to one side, and a pipe 50b extending to the defrosting device 6 side is connected to the other side There is. The second switching valve 54, which is a three-way switching valve, is connected to the downstream side of the pipe 50b, and the inside of the first defroster 61 of the defrosting device 6 is connected to the downstream side of the second switching valve 54. A first heat transfer pipe 51 disposed through is connected, and a second heat transfer pipe 52 disposed through the inside of the second defroster 62 of the defrosting apparatus 6 is connected to the other. Connected to the downstream side of the first heat transfer pipe 51 is a gate valve 55 for switching the opening / closing of the first heat transfer pipe 51 to the outside of the cooling device 1, and to the downstream side of the second heat transfer pipe 52. A gate valve 56 for switching between opening and closing of the heat transfer pipe 52 to the outside of the cooling device 1 is connected.

  Although the direct illustration is omitted, the arrangement of the first heat transfer tube 51 will be described. The first heat transfer pipe 51 is disposed via two holes which are formed in the case 61 a of the first defroster 61 and which are inserted into and out of the case 61 a. The first heat transfer pipe 51 is inserted from the outside of the case 61a to the inside through the one hole, and the heat transfer portion 51a, which is a part of the first heat transfer pipe 51, is directed from one hole to the other It is helically disposed along the inner wall of the case 61a, and is inserted from the inside of the case 61a to the outside through the other hole. In addition, since the space between the first heat transfer pipe 51 and each hole is closed in a sealed manner, the air refrigerant in the first defroster 61 and the outside air outside the first defroster 61 may be mixed. It is prevented. Furthermore, the gate valve 55 of the defrosting flow path 50 is connected to the end of the first heat transfer pipe 51 inserted to the outside of the case 61 a through the other hole.

  The arrangement of the second heat transfer pipe 52 of the defrosting flow passage 50 with respect to the second defroster 62 and the heat transfer portion 52a which is a part thereof is the same as that of the defrosting flow passage 50 with respect to the first defroster 61. Since the arrangement of the first heat transfer pipe 51 and the heat transfer portion 51a is substantially the same as that of the first heat transfer pipe 51, the description thereof will be omitted.

  Further, the cooling device 1 includes the motor 10, the inlet valve 8, the outlet valve 9, the detecting means 14, the first switching valve 53, the second switching valve 54, the gate valves 55, 56 of the flow path 50 for defrosting, and the defrosting. The control unit is electrically connected to the first switching valve 63, the second switching valve 64, the gate valves 65, 66, etc. of the device 6, and has a control unit (not shown) including a timer. On the basis of the information on the differential pressure of the first defroster 61 or the second defroster 62 received from 14 and the elapsed time of defrosting of the first defroster 61 and the second defroster 62, the valve is opened and closed. , And the cooling operation modes α, β, γ, δ, and ε as the cooling operation of the cooling device 1 can be switched and controlled.

  Next, cooling operation modes α, β, γ, δ, ε in the cooling operation of the cooling device 1 and cooling operation cycles S1, S2 by switching these will be described using FIGS. 3 (a) and 3 (b). In the cooling operation mode α, the second defroster 62 is defrosted in parallel with the dehumidification (normal state) of the air refrigerant by the first defroster 61 (defrost operation state). In the cooling operation mode β, precooling of the second defroster 62 is performed in parallel with the dehumidification of the air refrigerant by the first defroster 61. In the cooling operation mode γ, the air refrigerant is dehumidified by the second defroster 62 in parallel with the defrosting of the first defroster 61. In the cooling operation mode δ, the air refrigerant is dehumidified by the second defroster 62 in parallel with the precooling of the first defroster 61. In the cooling operation mode ε, the air refrigerant is dehumidified simultaneously and in parallel by the first defroster 61 and the second defroster 62.

  In the cooling operation cycle S1 shown in FIG. 3A, the cooling operation is repeatedly performed in the order of the cooling operation mode α, the cooling operation mode β, the cooling operation mode γ, and the cooling operation mode δ. In the case of this cooling operation cycle S1, one of the first defroster 61 and the second defroster 62 can be made to stand by in the pre-cooling state, so it is easy to maintain a constant dehumidifying capacity. Further, in the cooling operation cycle S2 shown in FIG. 3B, the cooling operation is repeatedly performed in the order of the cooling operation mode α, the cooling operation mode β, the cooling operation mode ε, the cooling operation mode γ, the cooling operation mode δ, and the cooling operation mode ε. Shows the manner in which the With this cooling operation cycle S2, a high dehumidification capacity can be exhibited during the cooling operation mode ε. The cooling operation cycles S1 and S2 may be in an aspect in which only one of them is operated, or in an aspect in which they are operated in combination. Although the cooling operation modes α, β, γ, δ and ε are performed so that they are substantially the same time (for example, 2 hours), they may be different.

  Next, the cooling operation modes α, β, γ, δ will be described by using the cooling operation cycle S1 as an example while showing various aspects of the cooling device 1 with reference to FIGS. 1 and 4 to 6. In the following description, based on the internal air A1 (about 1 atm, about -55 ° C.) in the cooled chamber 2, high pressure means that the pressure is higher than that of the internal air A1. Pressure refers to approximately the same pressure as in-chamber air A1, and the same temperature refers to a temperature within 10 ° C. of error compared to in-chamber air A1, and high temperature and low temperature are the same temperature. It indicates that the temperature is higher or lower than the temperature. The cooling operation mode ε will be described later.

  First, a cooling operation mode α which is one mode of the cooling operation of the cooling device 1 will be described using FIG. 1. In the cooling operation mode α, the defroster 6 is closed on the second defroster 62 side of the first switching valve 63 and the inlet valve 8, and the expansion turbine E and the cooled chamber 2 are separated via the first defroster 61. While being communicated, the bypass pipe 7n side of the outlet valve 9 and the gate valves 65, 66 are closed, and the cooling chamber 2 and the low temperature side pipe 4b of the second heat exchanger 4 are opened so as to be communicated. Thus, the cooling operation circulation flow path in the cooling operation mode α of the cooling device 1 is formed. Accordingly, in the second defroster 62, the flow path to the cooling operation circulation flow path is blocked by the first switching valve 63, the inlet valve 8, the second switching valve 64, and the gate valve 66.

  At this time, in the defrosting flow path 50, the pipe 50a side of the first switching valve 53 and the first heat transfer pipe 51 side of the second switching valve 54 are closed, and the third heat exchanger 5 is connected via the pipes 50c and 50b. The low temperature side flow passage 5b and the second heat transfer pipe 52 communicate with each other, and the gate valve 56 is in an open state. Along with this, the first heat transfer pipe 51 is closed by the second switching valve 54 and the gate valve 55. Thus, the outside air taken into the pipe 50d by the fan F2 becomes the outside air A11 heated by heat exchange with the high-pressure high-temperature air A2 in the third heat exchanger 5, and passes through the second heat transfer pipe 52. After the second defroster 62 is defrosted, the second defroster 62 is discharged to the outside of the cooling device 1 through the opened gate valve 56.

  When the compressor C and the expansion turbine E are driven, the compressor C sucks and compresses the normal-pressure high-temperature air A1 '(about 1 atm, about 40 ° C) in the pipe 7j. The high-pressure high-temperature air A2 compressed by the compressor C is about 2 atm and about 120 ° C., and is discharged to the high temperature side flow passage 5a of the third heat exchanger 5 through the pipe 7a.

  During the cooling operation, since the outside air taken in by the fan F2 passes through the low temperature side flow passage 5b of the third heat exchanger 5, the high pressure discharged to the high temperature side flow passage 5a of the third heat exchanger 5 The high temperature air A2 is heat-exchanged with the outside air of the low temperature side flow passage 5b of the third heat exchanger 5, and becomes high pressure high temperature air A3 of about 2 atm and about 100 ° C. It is discharged.

  The high-pressure high-temperature air A3 discharged to the high-temperature side pipe 3a of the first heat exchanger 3 is heat-exchanged with the cooling water circulating through the low-temperature side pipe 3b of the first heat exchanger 3, The high-temperature high-temperature air A4 of ° C. is discharged to the high temperature side pipe 4a of the second heat exchanger 4.

  The high-pressure high-temperature air A4 discharged to the high-temperature side pipe 4a of the second heat exchanger 4 is sucked into the compressor C via the low-temperature side pipe 4b of the second heat exchanger 4 from the cooled chamber 2 The heat is exchanged with about 1 atm, about -55 ° C, and it becomes high pressure isothermal air A5 of about 2 atm, about -50 ° C, and is discharged to the expansion turbine E. At this time, part of the water contained in the high-pressure high-temperature air A4 is transferred to the inner peripheral surface of the high-temperature side pipe 4a of the second heat exchanger 4 by heat exchange with the high-temperature high-temperature air A4. Since it adheres as frost, the amount of water contained in the high-pressure same-temperature air A5 discharged to the expansion turbine E decreases. On the other hand, the internal air A1 at about -55 ° C exchanges heat with the high-pressure high-temperature air A4 to become normal-pressure high-temperature air A1 'at about 40 ° C and flows into the pipe 7j.

  The high pressure same-temperature air A5 discharged to the expansion turbine E is expanded by the expansion turbine E to become normal pressure low-temperature air A6 of about 1 atm and about -90 ° C, and the moisture contained in the normal pressure low-temperature air A6 A part becomes frost and mixes with cold air, and is discharged to the defroster 6.

  The normal pressure low temperature air A 6 discharged to the defrosting device 6 is guided by the first switching valve 63 of the defrosting device 6 and discharged to the first defroster 61. When passing through the mesh member 61b of the first defroster 61, the frost contained in the atmospheric pressure low temperature air A6 adheres to the mesh member 61b, whereby the atmospheric pressure having a moisture content smaller than that of the atmospheric pressure low temperature air A6 It becomes low temperature air A7 (about 1 atm, about -90 ° C). The normal pressure low temperature air A 7 is guided to the inlet valve 8 and discharged to the cooled chamber 2. As described above, since moisture is removed by the first defroster 61 from the normal pressure low-temperature air A6 expanded by the expansion turbine E (dehumidification of air refrigerant), it is possible to suppress the frost from blowing out into the chamber 2 to be cooled.

  At this time, since the flow of the heated outside air A11 and the outside air is prevented from flowing into the first heat transfer pipe 51 of the defrosting flow path 50, the first defroster via the first heat transfer pipe 51 It is prevented that the temperature in 61 is heated.

  The normal pressure low-temperature air A7 discharged into the to-be-cooled chamber 2 is mixed with the air or the like flowing from the outside of the to-be-cooled chamber 2 to become the in-chamber air A1 of about -55 ° C.

  On the other hand, in the second defroster 62 of the defroster 6, since the heat transfer portion 52a of the second heat transfer pipe 52 of the defrosting flow path 50 is disposed inside the second defroster 62, As the heated outside air A11 passes through the second heat transfer pipe 52, residual air in the second defroster 62, a case 62a of the second defroster 62, a mesh member 62b (see FIG. 2B), etc. It is possible to heat the frost adhering to the Thereby, the frost accumulated in the second defroster 62 can be melted.

  As shown in FIG. 2B, the bottom surface 62c of the second defroster 62 is formed in a mortar shape, and the lowermost portion of the bottom surface 62c of the second defroster 62 communicates with the outside. An open / close drain valve 62d is provided. According to this, it is possible to discharge the water generated by melting the frost to the outside through the drain valve 62d.

  Further, although the residual air in the second defroster 62 is heated, since the flow path to the cooling operation circulation flow path side is blocked, for the cooling operation by the heated residual air The heating of the air refrigerant circulating in the circulation channel is prevented.

  From the above, in the cooling operation mode α of the cooling device 1, the second defroster 62 is operated in parallel with the dehumidification of the air refrigerant by the first defroster 61 while fully cooling the inside of the chamber 2 to be cooled. Defrost can be done.

  The cooling device 1 is switched to the cooling operation mode β by the control of the control unit when a predetermined time (for example, 2 hours) elapses after the cooling operation mode α is started by a timer included in the control unit (not shown) of the cooling device 1 Be The predetermined time measured by the timer may be any time as long as defrosting is reliably performed, and can be appropriately changed.

  Next, a cooling operation mode β which is one aspect of the cooling operation of the cooling device 1 will be described using FIG. 4. In the description of the cooling operation mode β, the description overlapping with the cooling operation mode α is omitted. In the cooling operation mode β, the defroster 6 is closed at the second defroster 62 side of the first switching valve 63 and the inlet valve 8, and the expansion turbine E and the cooled chamber 2 are connected via the first defroster 61. While being communicated, the piping 7h side of the outlet valve 9, the piping 60e side of the second switching valve 64, and the gate valve 65 are closed, the gate valve 66 is opened, and the cooling chamber is opened via the second defroster 62 It is open | released so that 2 and 2nd heat exchanger 4 low temperature side piping 4b may connect. Thus, the cooling operation circulation flow path in the cooling operation mode β of the cooling device 1 is formed.

  At this time, the defrosting flow path 50 is in a state in which the pipe 50b side of the first switching valve 53 and the gate valves 55, 56 are closed. As a result, the heated outside air A11 is discharged from the pipe 50a to the outside of the cooling device 1, and the outside air is prevented from flowing into the second heat transfer pipe 52.

  The internal air A1 discharged from the cooling chamber 2 passes through the pipe 7g, the outlet valve 9, the bypass pipe 7n, the second switching valve 64 of the defrosting apparatus 6, the pipes 60f and 60d, and the second defroster 62 Is discharged. As a result, residual air that has been heated by the defrost of the second defroster 62 is discharged from the second defroster 62, and the pipe 60b, the second bypass passage 72, the pipe 7h, and the second heat exchange It passes through the low temperature side pipe 4b and the pipe 7j of the vessel 4 and is discharged to the compressor C as normal pressure high temperature air A1 '. Similarly, the internal air A1 passes through the second defroster 62 and continues to be discharged to the compressor C as normal-pressure high-temperature air A1 ′, so that the temperature in the second defroster 62 can be The temperature can be lowered to about the same temperature. Thus, by precooling the second defroster 62, the residual air in the second defroster 62 heated by the defrost is prevented from being directly discharged to the cooled chamber 2, and 2. Due to the temperature difference between the temperature inside the defroster 62 and the normal pressure low temperature air A6, it is possible to suppress the temperature rise of the normal pressure low temperature air A6 discharged to the second defroster 62 after defrosting. That is, the temperature in the cooled chamber 2 can be suitably maintained.

  At this time, since the heated outside air A11 and the outside air are prevented from flowing into the second heat transfer pipe 52, the temperature in the second defroster 62 is heated via the second heat transfer pipe 52. It is prevented from being warmed. Thereby, precooling in the 2nd defroster 62 can be performed suitably.

  From the above, in the cooling operation mode β of the cooling device 1, the second defroster 62 is performed in parallel with the dehumidification of the air refrigerant by the first defroster 61 while fully cooling the inside of the chamber 2 to be cooled. You can do pre-cooling. In addition, since the second defroster 62 can be precooled without preparing a separate cooling device, energy efficiency is good.

  As described above, the cooling device 1 controls the cooling device 1 when the detection means 14 detects that the differential pressure between the upstream side and the downstream side of the first defroster 61 has become equal to or greater than a predetermined threshold value. The part switches the cooling operation mode β to the cooling operation mode γ.

  Next, a cooling operation mode γ which is one mode of the cooling operation of the cooling device 1 will be described with reference to FIG. In the description of the cooling operation mode γ, the description overlapping with the cooling operation modes α and β is omitted. In the cooling operation mode γ, the expansion turbine E and the cooled chamber 2 communicate with each other through the second defroster 62, and the low temperature side piping of the cooled chamber 2 and the second heat exchanger 4 It is opened so as to communicate with 4b. The normal pressure low temperature air A6 flowing into the defrosting apparatus 6 passes through the second defroster 62 to become normal pressure low temperature air A7 having a water content smaller than that of the normal pressure low temperature air A6. It is discharged.

  At this time, in the defrosting flow path 50, the heated outside air A11 passes through the first heat transfer pipe 51 to defrost the first defroster 61, and then the cooling device 1 via the opened gate valve 55. Discharged to the outside of the

  In the first defroster 61 of the defrosting apparatus 6, when the heated outside air A 11 passes through the first heat transfer pipe 51, the frost accumulated in the first defroster 61 can be melted. The first defroster 61 guides the water generated by melting the frost by the bottom surface 61c (see FIG. 2B) of the first defroster 61, and the drain valve 61d of the first defroster 61 (see FIG. It can be discharged to the outside through FIG. 2 (b)). Further, since the flow passage to the cooling operation circulation flow passage side is closed, heating of the air refrigerant circulating in the cooling operation circulation flow passage by the heated residual air is prevented.

  From the above, in the cooling operation mode γ of the cooling device 1, the air refrigerant by the second defroster 62 in parallel with the defrosting of the first defroster 61 while sufficiently cooling the inside of the chamber 2 to be cooled Dehumidification can be performed.

  The cooling device 1 is switched to the cooling operation mode δ by the control of the control unit when the cooling operation mode γ is started and a predetermined time passes by a timer provided in a control unit (not shown) of the cooling device 1.

  Next, a cooling operation mode δ which is one mode of the cooling operation of the cooling device 1 will be described with reference to FIG. In the description of the cooling operation mode δ, the description overlapping with the cooling operation modes α, β, γ will be omitted. In the cooling operation mode δ, the defrosting device 6 allows the expansion turbine E and the cooled chamber 2 to communicate with each other via the second defroster 62, and the cooled chamber 2 and the first to be cooled via the first defroster 61. The low temperature side pipe 4 b of the two heat exchangers 4 is opened so as to be in communication. As a result, the first defroster 61 is precooled by the in-compartment air A1 discharged from the to-be-cooled chamber 2.

  At this time, since the heated outside air A11 and the outside air are prevented from flowing into the first heat transfer pipe 51, the temperature in the first defroster 61 is heated via the first heat transfer pipe 51. It is prevented from being warmed. Thereby, precooling in the 1st defroster 61 can be performed suitably.

  From the above, in the cooling operation mode δ of the cooling device 1, the first defroster 61 is performed in parallel with the dehumidification of the air refrigerant by the second defroster 62 while sufficiently cooling the inside of the chamber 2 to be cooled. You can do pre-cooling.

  The cooling device 1 cools by the control unit of the cooling device 1 when the detection means 14 ′ detects that the differential pressure between the upstream side and the downstream side of the second defroster 62 has become equal to or greater than a predetermined threshold. The operation mode δ is switched to the above-described cooling operation mode α.

  Next, the cooling operation cycle S2 will be described with reference to FIG. In the cooling operation cycle S2, as described above, the cooling operation is repeatedly performed in the order of the cooling operation modes α, β, ε, γ, δ, and ε. Description of the cooling operation modes α, β, γ, δ in the cooling operation cycle S2 will be omitted because they are as described above. In the cooling device 1 ′, a gate valve 163a is connected upstream of the first defroster 61, a gate valve 108a is connected downstream of the first defroster 61, and upstream of the second defroster 62. The difference is the same as the cooling device 1 of the embodiment except that it is connected to the gate valve 163b and connected to the downstream side of the second defroster 62 with the gate valve 108b.

  Specifically, the upstream side of the gate valve 163a, 163b is connected to the pipe 173a, 173b (flow path) branched into two equal distribution from the downstream side of the pipe 7e, and the downstream side of the gate valve 163a, 163b is the pipe 160a, 160b It is connected to the (flow path), and is connected to the first defroster 61 or the second defroster 62 through the pipes 160a and 160b. The upstream sides of the gate valves 108a and 108b are connected to the pipes 160c and 160d (communication paths), and are connected to the first defroster 61 or the second defroster 62 via the pipes 160c and 160d, and the gate valve 108a , 108 b are connected to pipes 174 a, 174 b (communication path) branched into two equal distribution from the upstream side of the pipe 7 f.

  In this embodiment, the first defroster 61 (the second defroster) is opened by opening the gate valves 163a and 108a (gate valves 163b and 108b) and closing the gate valves 163b and 108b (gate valves 163a and 108a). The expansion turbine E and the cooled chamber 2 can be connected via the defroster 62), and the first defroster 61 (the second defroster 62) can be connected to the second defroster 62 (the first defroster 62). It is possible to prevent the air in the defroster 61) from being mixed. That is, the same cooling operation as the cooling operation modes α, β, γ, δ in the above embodiment can be performed.

  In the cooling operation cycle S2, the cooling operation mode ε is switched to when the predetermined time passes after the cooling operation mode β or the cooling operation mode δ is started. The control unit (not shown) of the cooling device 1 ′ has a temperature sensor to which the control unit (not shown) is electrically connected, and the temperature sensor is disposed in the first defroster 61 and the second defroster 62, and the temperature is The cooling operation mode ε may be switched in response to the internal temperature detected by the sensor becoming lower than a predetermined temperature (for example, −55 ° C.). Furthermore, the predetermined temperature is not limited to -55 ° C.

  In the cooling operation mode ε, in the defrosting device 6 ′, the gate valves 163 a, 108 a, 163 b and 108 b are simultaneously opened. Thereby, the normal pressure low temperature air A6 is simultaneously discharged to the first defroster 61 and the second defroster 62, and the first defroster 61 and the second defroster 62 simultaneously defrost the air refrigerant. be able to. The three-way switching valve used for the first switching valve 63 and the inlet valve 8 of the defrosting device 6 of the cooling device 1 shown in FIG. 1 and FIGS. 4 to 6 has one of the three insertion holes. If it is possible not only to close the block but also to open all the three insertion holes, the cooling operation mode ε can be performed as in this embodiment.

  At this time, the defrosting flow path 50 is in a state in which the pipe 50b side of the first switching valve 53 and the gate valves 55, 56 are closed.

  When the cooling operation mode β is switched to the cooling operation mode ε, when the detection means 14 detects that the differential pressure between the upstream side and the downstream side of the first defroster 61 has become equal to or greater than a predetermined threshold value, The control unit of the cooling device 1 switches the cooling operation mode ε to the cooling operation mode γ. Similarly, when the cooling operation mode δ is switched to the cooling operation mode ε, the cooling operation mode ε is switched to the cooling operation mode α. In addition, regardless of the cooling operation modes β and δ before the cooling operation mode ε, the cooling operation is simply performed to perform the defrosting on the side where a pressure difference greater than or equal to a predetermined threshold is detected from one of the detection means 14 and 14 ′. The mode may be switched from the mode ε to the corresponding cooling operation mode α or γ.

  As described above, the cooling devices 1 and 1 'can perform desired cooling stably in the cooled chamber 2 by the cooling operation cycles S1 and S2.

  As described above, the cooling device 1 or 1 'in the present embodiment cuts off the pipe 60b or the pipes 173a and 160a ((the pipe 60a or the pipes 173b and 160b) (one flow path) to block the pipe 60b. Or, when the second defroster 62 (first defroster 61) connected to the piping 173b, 160b) (the piping 60a or the piping 173a, 160a) (the other flow path) is put into the defrosting operation state, the first removal is performed. Since the defroster 61 (second defroster 62) communicates with the to-be-cooled chamber 2, the cooling operation of the to-be-cooled chamber 2 can be continuously performed as a whole of the cooling devices 1 and 1 '.

  The pipes 60a and 60b (pipes 173a, 160a, 173b and 160b) to which the first defroster 61 and the second defroster 62 are connected are respectively connected to the first switching valve 63 (divided valve 163a) on the upstream side. , 163b), the normal state or the defrosting operation state of the first defroster 61 and the second defroster 62 can be easily controlled.

  Further, since the first switching valve 63 of the defrosting device 6 is a three-way switching valve, when one of the first defrosters 61 (second defroster 62) is defrosted (defrosting operation state), The other second defroster 62 (first defroster 61) reliably communicates with the chamber 2 to be cooled.

  In addition, on the downstream side of the first defroster 61 and the second defroster 62, the pipes 60c, 60d, 60e, 60f that connect the first defroster 61 and the second defroster 62 (pipes 160c, 174a , 160d, 174b, 60e, 60f) (communication path) is provided, and the inlet valve 8 (separator valve 108a or sluice valve 108b) for connecting the pipes 60c, 60d (the pipes 160c, 174a or the pipes 160d, 174b), Alternatively, the first defroster 61 and the second defroster 62 are not in communication with the communication state by the second switching valve 64 of the defrosting devices 6, 6 'that connect the pipes 60e, 60f of the defrosting devices 6, 6'. Since the pipes 60c, 60d (the pipes 160c, 174a, 160d, 174b) or the pipes 60e, 60f of the defrosting apparatuses 6, A first defrost 61 which bets operation is completed (second defrost 62), it can be pre-cooled by the air passing through the second defrosting 62 (first defrost 61).

  Also, the pipes 60c, 60d, 60e, 60f (pipes 160c, 174a, 160d, 174b, 60e, 60f), pipes 7f, 7g, bypass pipe 7n, inlet valve 8 (gate valve 108a or gate valve 108b), cooled chamber A communication passage communicating the downstream sides of the first defroster 61 and the second defroster 62 is formed by the outlet valve 9 and the second switching valve 64 of the defrosting devices 6 and 6 '. As a result, it is possible to precool the first defroster 61 (second defroster 62) for which defrosting has been completed, by the air passing through the second defroster 62 (first defroster 61). Specifically, the air after being discharged from the second defroster 62 (first defroster 61) and passing through the cooled chamber 2 is the first defroster 61 (second defroster 62) after the defrosting operation There is no effect on the temperature of the air in the chamber 2 to pre-cool the air.

  Moreover, since the first defroster 61 (second defroster 62) is connected to the compressor C via the first bypass passage 71 (second bypass passage 72), the first defroster 61 (second defroster 62) After pre-cooling the second defroster 62), the first defroster 61 is opened by opening the gate valve 65 (gate valve 66) and bringing the first bypass passage 71 (second bypass passage 72) into communication. The air after precooling (the second defroster 62) can be discharged to the compressor C without returning to the cooled chamber 2 side.

  Further, the defrosting flow path 50 extends to the vicinity of the first defroster 61 and the second defroster 62, and the first heat transfer pipe 51 and the second heat transfer pipe 52 are respectively the second defroster 62 and the second defroster. Since it is disposed inside the defroster 62, the first defroster 61 or the second removing device is heated by the outside air A11 heated using the high-pressure high-temperature air A2 (hot air) compressed by the compressor C. Since the defroster 62 can be warmed, it is not necessary to prepare a separate heater etc., and the structure of the cooling device 1, 1 'can be simplified.

  Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and any changes or additions may be made without departing from the scope of the present invention. Be

  For example, although the defrosting devices 6, 6 'have been described as a mode having the first defroster 61 and the second defroster 62 in the above embodiment, the present invention is not limited to this and three or more defrosters may be used. You may have. Moreover, it may have another flow path which is not directly connected to a defroster, or a plurality of defrosters may be connectable in series.

  In precooling of the first defroster 61 (the second defroster 62), the second switching valve 64 is operated to make the first defroster 61 and the second defroster 62 directly communicate with each other, and the second defroster A portion of the normal pressure low-temperature air A7 discharged from the 62 (first defroster 61) may be discharged to the first defroster 61 (second defroster 62).

  The defrosting channel 50 has been described as a mode in which the outside air passes, but is not limited to this, and may be a refrigerant other than air, such as water or oil, or may be a mode in which the refrigerant passes or circulates. From this, the third heat exchanger 5 is not limited to the air cooling type, and similarly, the first heat exchanger 3 and the second heat exchanger 4 are not limited. In addition, the third heat exchanger 5 may not be used, and the first heat exchanger 3 may also serve as the defrosting flow path, and the pipe between the compressor C and the first heat exchanger 3 is the defrosting flow path And may not be limited to the defrosting channel 50.

  The heat transfer portion 51a, which is a part of the first heat transfer pipe 51, is spirally disposed along the inner wall of the case 61a from one hole of the case 61a of the first defroster 61 toward the other hole. However, the present invention is not limited to this, and the case 61a may be arranged linearly from one hole of the case 61a of the first defroster 61 to the other hole. It may be disposed spirally along the outer wall without penetrating, and in the embodiment in which the heat insulating material is filled between the outer wall and the inner wall, along the inner wall in the space between the outer wall and the inner wall It may be an aspect in which it is disposed, and it is not limited. That is, after the heat transfer tube extends to the vicinity of the defroster, the heat transfer tube may penetrate the defroster, may be wound around an outer wall portion, and may be embedded in the case.

  In the cooling operation cycles S1 and S2, after the first defroster 61 or the second defroster 62 has been defrosted, it has been described that precooling is performed immediately. However, the present invention is not limited to this. There may be a mode of standby where neither pre-cooling nor pre-cooling is performed.

  The cooling operation of the cooling devices 1 and 1 'may be stopped, and the defrosting operation of the cooling devices 1 and 1' may be performed. A heater may be used as a heat source at this time.

1, 1 'Cooling device 2 cooled room 3 1st heat exchanger 4 2nd heat exchanger 5 3rd heat exchanger 6, 6' defrosting device 7f, 7g Piping (communication path)
7n bypass pipe (communication passage)
8 Inlet valve (valve)
50 Defrosting channel 60a, 60b Piping (flow channel)
60c to 60f piping (communication path)
61 1st defroster 62 2nd defroster 63 1st change over valve (valve)
71 first bypass passage 72 second bypass passage 108a, 108b gate valve (valve)
160a, 160b piping (flow path)
160c, 160d piping (communication path)
163a, 163b gate valve
173a, 173b piping (flow path)
174a, 174b Piping (communication passage)
C Compressor E Expansion Turbine

Claims (7)

From the compressor for compressing the air recovered from the cooled chamber, the heat exchanger for cooling the air compressed by the compressor, the expander for expanding the air cooled by the heat exchanger, and the expander A cooling device using an air refrigerant cycle comprising: a defrosting device for collecting as a frost the water contained in the air flowing into the room to be cooled;
The defrosting apparatus includes a flow path branched from the expander into a plurality, and a defroster connected to at least two flow paths of the plurality of flow paths, respectively.
The air refrigerant cycle is characterized in that when one of the flow paths to which the defroster is connected is shut off, the other flow path communicates with the cooled chamber. Cooling device used.   The flow path to which the defroster is connected and the other flow path are provided with at least one valve on the upstream side or the downstream side of each of the one flow path and the other flow path. Cooling device using an air refrigerant cycle.   The said valve is a switching valve which controls said one flow path and said other flow path, The cooling device using the air refrigerant | coolant cycle of Claim 2 characterized by the above-mentioned.   On the downstream side of the defrosters respectively connected to the at least two flow paths, there is provided a communication passage for communicating the defrosters with each other, and the communication passages are in communication and non-communication states. The cooling device using an air refrigerant cycle according to any one of claims 1 to 3, which is switchable.   The cooling device using an air refrigerant cycle according to claim 4, wherein the to-be-cooled chamber is provided in the middle of the communication passage.   The defrosters respectively connected to the at least two flow paths are each provided with a bypass passage communicating with the compressor, and the bypass passage can be switched between the communicating state and the non-communicating state A cooling device using an air refrigerant cycle according to any one of claims 1 to 5, characterized in that:   The air refrigerant cycle according to any one of claims 1 to 6, wherein a flow path for transferring heat between the compressor and the heat exchanger extends to the vicinity of the defroster. Cooling device used.

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