JP2008180449A - Air-coolant refrigeration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-coolant refrigeration system with high energy efficiency, capable of reducing facility costs by miniaturizing and simplifying a facility. <P>SOLUTION: The air-coolant refrigeration system has a freezer 1 forming a freezing space, a compressor 3 sucking in air of the freezer 1 and carrying out adiabatic compression, a primary cooler 5 cooling compressed air by heat exchange with a cooling fluid, and an expander 2 carrying out adiabatic expansion of the cooled compressed air. Low temperature air provided by the expander 2 is supplied to a freezing chamber to form the freezing space. The freezing space is partitioned into two communicated spaces via a heat insulating material 10, one space is used as a working space 11 cooling an object to be cooled, another space is used as a discharge space 15 discharging air used in cooling, a cold absorbing path 22 passing air having passed through the primary cooler 5 is provided in the discharge space, and air passing through the cold absorbing path is cooled to a predetermined temperature by heat exchange with the low temperature air flowing in from the working space 11 and passing through the discharge space 15. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air refrigerant refrigeration apparatus that cools a refrigeration space by directly adiabatically compressing and then adiabatically expanding air, and in particular, has a compact and simplified apparatus configuration and can improve energy efficiency. The present invention relates to an air refrigerant refrigeration apparatus.

Conventionally, chlorofluorocarbon refrigerants have been often used as refrigerants for refrigeration equipment, but ozone layer destruction by chlorofluorocarbon gas has become a problem, and its use is being restricted from the viewpoint of global environmental conservation. In addition, an ammonia-based refrigerant is used as an alternative refrigerant, but this ammonia-based refrigerant also has a problem in terms of safety. Therefore, in recent years, air refrigerants that do not adversely affect the environment and have high safety are attracting attention. A refrigeration apparatus using an air refrigerant is an apparatus that cools a refrigeration space by adiabatic expansion after directly adiabatically compressing air. In a refrigeration system using a CFC-based refrigerant or an ammonia-based refrigerant, the cooling space is indirectly cooled by a heat exchanger through which the refrigerant flows. Since the cooling is performed, the heat exchanger is unnecessary and, at the same time, a defrosting operation for maintaining the heat exchanger performance is unnecessary.
However, air refrigerant refrigeration apparatuses that cannot use latent heat are more efficient (COP: COP) than conventional fluorocarbon refrigerant or ammonia refrigerant refrigeration apparatuses that involve a liquid / gas phase change in compression / expansion operations. The coefficient of performance is low. In addition, there is a problem that the apparatus is enlarged.

  On the other hand, in the food industry market, frozen foods have become highly popular, and in addition, they are aiming for high-quality and safe foods, and the need for freezing and refrigeration in the temperature range of -60 ° C or lower has increased. Yes. However, in the air refrigerant refrigeration system, the temperature coefficient of the coefficient of performance is less dependent on the temperature range that has been frequently used in the past than the refrigeration system that uses chlorofluorocarbon refrigerant or ammonia refrigerant. It turned out that it reversed from the vicinity of -50 degreeC depending on some, and efficiency became higher than the conventional freezing system. That is, in cryogenic freezing and refrigeration, it is predicted that an era in which the air refrigerant refrigeration apparatus will prevail will be reached along with the environmental safety problems described above.

  The basic configuration of such an air refrigerant refrigeration apparatus is, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-90599) and the like, a compressor that generates high-temperature and high-pressure air, Or it comprises a heat exchanger that cools by heat exchange with cooling water, an expander that adiabatically expands the cooled air, and a freezer compartment that is supplied with low-temperature air obtained by the adiabatic expansion. In such an air refrigerant refrigeration apparatus, if the discharge pressure of the compressor is increased, the power of the compressor increases, so it is desired to reduce this pressure. However, if the discharge pressure is low, a sufficient cooling temperature cannot be obtained with only the heat exchanger, so Patent Document 2 (Japanese Patent Laid-Open No. 2005-265349), Patent Document 3 (Japanese Patent Laid-Open No. 2006-71128), and the like. As described in the above, there is known a configuration including a heat recovery heat exchanger for lowering the temperature by exchanging heat of the air first cooled in the heat exchanger with the cold heat discharged from the freezer compartment. .

An example of a refrigeration apparatus equipped with a heat exchanger for cold energy recovery is shown in FIG. As shown in the figure, the air refrigerant refrigeration apparatus sucks air at −60 ° C. or less, relative humidity 85%, and atmospheric pressure in the freezer 51 and guides it to the cold heat recovery heat exchanger 52, and the heat exchanger 52 Through the heat transfer surface, heat exchange is performed with the high-pressure air after the primary cooling led from the primary cooler 56 to the expander 54, and the cold air of the low-temperature air from the freezer 51 is given to the high-pressure air after the primary cooling. The air whose temperature has risen is compressed to the required pressure by the compressor 53, and the temperature further rises. Therefore, the air is cooled by the primary cooler 56 and cooled to near room temperature. Further, as described above, in the heat exchanger 52 for recovering cold heat The temperature is lowered and introduced into the expander 54. It expands to near atmospheric pressure with an expander 54 to obtain cold air of −70 ° C. or less, and this cold air is directly supplied into the freezer 51 to keep the inside of the refrigerator in a freezing space.
This heat recovery heat exchanger 52 is used to improve the thermal efficiency, and is particularly suitable for maintaining the discharge pressure of the compressor 53 low, and cools the air to a desired temperature even if the discharge pressure is small. Will be able to.

JP 2006-90599 A JP 2005-265349 A JP 2006-71128 A

For example, an aluminum finned plate is used for the heat recovery heat exchanger described in Patent Document 2 and Patent Document 3 described above, and this heat exchanger requires a significant temperature drop of the air refrigerant. As a result, the apparatus becomes large. In addition, in this heat exchanger, since the heat insulation function must be maintained high, conventionally, a foam type heat insulation material such as a style home has been configured with a thickness of about 100 mm. However, this heat insulation material further increases the size of the device. As a result, there was a problem that the equipment cost would increase. In particular, if the discharge pressure from the compressor is to be kept small, the heat recovery heat exchanger must be made large, and a configuration that can simultaneously improve energy efficiency, reduce equipment size, and reduce equipment costs. It has been demanded.
Therefore, in view of the above-mentioned problems of the conventional technique, the present invention has an object to provide an air refrigerant refrigeration apparatus that can reduce the equipment cost by reducing the size and simplification of the equipment and has high energy efficiency.

Therefore, in order to solve such a problem, the present invention cools the compressed air by heat exchange with a cooling fluid, a freezing chamber that forms a freezing space, a compressor that sucks air in the freezing chamber and adiabatically compresses it, and a cooling fluid. An air refrigerant refrigeration apparatus having a primary cooler that performs heat expansion and an expander that adiabatically expands the cooled compressed air and supplies the low-temperature air obtained by the expander to the freezer compartment In
The freezing space is partitioned into two communicating spaces through a heat insulating material, one space is a working space for cooling the object to be cooled, and the other space is a discharge space for discharging the air used for cooling,
In the discharge space, a cold heat absorption path through which the primary cooled air passes through the primary cooler is provided, the cold heat absorption path is connected to the suction side of the expander,
The air passing through the cold heat absorption path is cooled to a predetermined temperature by heat exchange with low-temperature air flowing in from the working space and passing through the discharge space.

  According to the present invention, the heat recovery heat exchanger that has been installed separately from the freezer compartment is incorporated in the freezer compartment, so that the apparatus can be downsized and simplified while maintaining a high energy efficiency state. It becomes possible, and the equipment cost can be reduced. Further, by adopting such a configuration, the heat insulating material used in the heat recovery heat exchanger can be reduced, and the thickness of the heat insulating material installed in the freezer compartment of the present invention can be reduced by the conventional heat recovery heat exchange. It can be made thinner than the thermal insulation used in the vessel.

Further, a foreign matter existing in the air that has passed through the discharge space downstream of the discharge space or between the freezer compartment and the compressor with respect to the flow direction of the air flowing into the discharge space from the working space. A foreign matter removing filter is provided to remove water.
According to the present invention, the foreign matter scattered in the freezing chamber can be removed by the foreign matter removal filter, and the foreign matter is prevented from being mixed into the system of the refrigeration cycle, and the foreign matter is clogged in the compressor and fails. Can be prevented.
Further, in the present invention, since the foreign matter removal filter can be used in an atmosphere at a substantially normal temperature, the structure of the foreign matter removal filter can be simplified and maintenance can be easily performed. In the maintenance, the foreign matter removal filter is periodically or continuously cleaned, but the thermal load applied to the refrigeration space can be reduced during this cleaning.

Further, the foreign matter removal filter is a roll filter, a filter cleaning means is provided in a part of the roll filter, a pressure sensor for detecting the suction pressure of the compressor is provided, and the pressure sensor detects the suction pressure based on the detected suction pressure. The operation of the filter cleaning means is controlled.
According to the present invention, the foreign matter can be continuously removed by using the roll filter as the foreign matter removing filter. In addition, by using a roll filter, the cleaning device can be cleaned and maintained only by being provided in a part of the filter, so that the cleaning device can be downsized. In addition, by operating the filter cleaning means based on the suction pressure of the compressor, the filter cleaning can be automatically performed even when the filter cannot be completely clogged. Of course, when performing filter cleaning, a roll filter winding operation is also performed at the same time.

The filter cleaning means is installed below the roll filter,
A hot waste water injection means for injecting the hot waste water obtained by the primary cooler from below with respect to the filter surface; and at least a rear side of the hot waste water injection means with respect to the moving direction of the roll filter; And scraping means for scraping off foreign matter adhering to the roll filter.
In this way, by using the hot waste water obtained from the primary cooler for filter cleaning, there is no need to introduce cleaning water from other sources, and it is possible to reduce boiler heavy oil that was conventionally used to heat cleaning water. Water saving and energy saving can be realized.

Furthermore, a suction side filter having a larger opening than the foreign matter removal filter is provided upstream or upstream of the discharge space to remove foreign matter and ice in the low-temperature air that has passed through the working space.
According to the present invention, by installing the suction filter upstream of the discharge space, it is possible to remove large ice (including snow) that is generated when the moisture load increases. In addition, since there is a possibility that a large foreign matter is mixed and the foreign matter removal filter alone may cause clogging, the foreign matter can be prevented from entering the system by performing two-stage filtering as in the present invention. Can do.

Furthermore, a hot water tank for storing the hot waste water obtained by the primary cooler, and a hot waste water supply path for supplying the hot waste water in the hot water tank to the freezer compartment, the hot waste water being supplied to the freezer compartment It is characterized by being used for cleaning.
According to this, heat can be effectively used by collecting and storing the heat that has been thrown away from the primary cooler to the outside air in the hot water tank.

As described above, according to the present invention, by adopting a configuration in which a heat exchanger for recovering cold heat, which has been conventionally installed separately from the freezer compartment, is incorporated in the freezer compartment, the energy efficiency of the apparatus is maintained while maintaining a high energy efficiency state. Miniaturization and simplification are possible, and equipment costs can be reduced. Moreover, the heat insulating material used for the heat exchanger for cold-heat collection | recovery can be reduced by setting it as such a structure.
In addition, by installing a foreign matter removal filter downstream of the discharge space, foreign matter generated in the freezer compartment can be prevented from entering the refrigeration cycle, and problems in the refrigeration cycle such as a compressor failure can be prevented. . Furthermore, since the foreign matter removal filter can be used in an atmosphere at a substantially normal temperature, the structure of the foreign matter removal filter can be simplified and maintenance can be easily performed.
Furthermore, the filter cleaning device can be miniaturized by using the foreign matter removal filter as a roll filter. In addition, by operating the filter cleaning means based on the suction pressure of the compressor, the filter cleaning can be automatically performed even when the filter cannot be completely clogged.

In addition, by installing a suction-side filter upstream or upstream of the discharge space, it is possible to remove large ice when the moisture load increases. Since clogging may occur immediately, the inflow of powder into the system can be prevented by two-stage filtering.
Furthermore, by using the hot waste water obtained from the primary cooler for filter cleaning or freezer compartment cleaning, water saving and energy saving can be realized.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
1 is a block diagram of an air refrigerant refrigeration apparatus according to Embodiment 1 of the present invention, FIG. 2 is a block diagram of an air refrigerant refrigeration apparatus according to Embodiment 2 of the present invention, and FIG. 3 is an application of Embodiment 2 of FIG. FIG. 4, FIG. 4 is a diagram for explaining the filter of FIG. 3, FIG. 5 is a diagram obtained by applying Example 2 of FIGS. 2 and 3, and FIG. 6 is a configuration diagram of an air refrigerant refrigeration apparatus according to Example 3 of the present invention. FIG. 7 is a schematic view of a filter cleaning apparatus according to Embodiment 3 of the present invention.

With reference to FIG. 1, the basic structure of the air refrigerant freezing apparatus which concerns on a present Example is demonstrated.
The air refrigerant refrigeration apparatus according to the present embodiment has a refrigeration space surrounded by a heat insulating material, and in this refrigeration space, an object to be cooled is brought into contact with low-temperature air to cool to a freezing temperature or lower (freezer compartment) 1. It has. The air discharged from the air discharge port of the freezer 1 is cooled by a refrigeration cycle arranged in the order of the compressor 3, the primary cooler 5, and the expander 2, and the generated low-temperature air is supplied from the air intake port of the freezer 1. It is to be supplied into the cabinet.
Specifically, the air discharge port of the freezer 1 is connected to the suction side of the compressor 3 via the air discharge path 23, and the discharge side of the compressor 3 is connected to the air inlet of the primary cooler 5. The primary cooler 5 is a device that cools high-temperature and high-pressure air from the compressor 3 by heat exchange with cooling water such as well water or tap water. Further, the outlet side of the primary cooler 5 is connected to the suction side of the expander 2 through a cold heat absorption path 22 of the freezer 1 described later. The discharge side of the expander 2 is connected to the air intake port of the freezer 1. The rotary shafts of the compressor 3 and the expander 2 are connected to the drive shaft of the motor 4 so as to be driven.

Further, in the present embodiment, as a characteristic configuration, the function of a heat exchanger for cold energy recovery (see FIG. 8) that is conventionally provided separately from the freezer 1 is provided in the freezer 1.
Specifically, the freezing space in the freezer 1 is partitioned into two communicating spaces via the heat insulating material 10, and the space located on the air inlet side is defined as an action space 11 for cooling the object 30 to be cooled. The space located on the discharge port side is a discharge space 15 for discharging the cooled low-temperature air. The discharge space 15 is provided with a cold absorption path 22 through which the primary cooled air passes through the primary cooler 5. Here, heat exchange is performed between the high-temperature air passing through the cold absorption path 22 and the low-temperature air flowing into the discharge space 15 from the working space 11, and the air passing through the cold absorption path 22 is Cooling is applied from the low-temperature air in the freezer 1 to cool (secondary cooling), and it is guided to the expander 2. On the other hand, the air passing through the discharge space 15 is heated by heat exchange with the air in the cold absorption path 22 and discharged from the air discharge port of the freezer 1.

  The configuration of the cooling heat absorption path 22 is not particularly limited as long as a desired heat transfer efficiency can be obtained. For example, a configuration in which one or a plurality of tubes are disposed in the discharge space 15 or fins are attached to the tubes. Examples include a configuration in which the heat transfer area is increased, or a configuration in which one or a plurality of plates are provided. The material used for the cold heat absorption path 22 is a metal material having high heat conductivity, such as an aluminum alloy.

The working space 11 of the freezer 1 is not particularly limited as long as the object to be cooled 30 is cooled by low-temperature air. As an example of the working space 11, as shown in the figure, an object 30 to be cooled is placed on the conveyor 13, and the low-temperature air is supplied to the object 30 from the air jet 12 provided immediately above the conveyor 13. The coolant 30 is cooled by this collision flow. A plurality of air jet sections 12 are installed in the conveyor conveyance direction. With this configuration, the object to be cooled 30 is cooled to a predetermined temperature. The transport conveyor 13 uses a structure that allows air such as a mesh belt to pass downward through the conveyor belt, and the low-temperature air blown downward flows into the discharge space 15.
In this embodiment, it is preferable to provide a dehumidifying means in the system. The configuration of the dehumidifying means is not particularly limited. For example, a configuration in which a dehumidifying device is installed in the system or a dehumidifying agent such as a polymer compound is incorporated in the device can be employed.

Next, the operation of the air refrigerant refrigeration apparatus of the first embodiment will be described. The numerical values such as temperature, pressure, and relative humidity described here are merely examples, and the present invention is not limited thereto.
First, air at −60 ° C. or less and atmospheric pressure flows from the air intake port of the freezer 1 into the refrigeration space, and is ejected into the working space 11 through the air jet 12 to cool the object 30 to be cooled. The low-temperature air of about −60 ° C. that has passed through the working space 11 flows into the discharge space 15 and is heat-exchanged with the high-temperature side air of 40 ° C. that passes through the cold absorption path 22, and the low-temperature air is heated to about 35 ° C. And discharged from the air outlet. On the other hand, the high temperature side air of 40 ° C. that has passed through the cold heat absorption path 22 is secondarily cooled to about −55 ° C. and discharged.

The air of about 35 ° C. exiting the air discharge port of the freezer 1 is guided to the compressor 2 and is compressed by the compressor 2 to become high-temperature high-pressure air having a temperature of 90 ° C. and a pressure of 0.17 MPa. The high-temperature and high-pressure air is cooled to 40 ° C. by the cooling water in the primary cooler 5 and then introduced into the cold recovery path 22 installed in the discharge space 15 of the freezer 1. Then, in the cold recovery path 22, it is secondarily cooled to −55 ° C. and discharged as described above.
The air exiting the cold heat recovery path 22 is introduced into the expander 3 and expanded to near atmospheric pressure by the expander 3 to obtain low temperature air of −60 ° C. or less, preferably about −80 ° C. Is directly supplied to the freezer 1 to keep the inside of the refrigerator in a freezing space.

  According to this embodiment, since the heat recovery heat exchanger that has been installed separately from the freezer 1 is incorporated in the freezer 1, the apparatus can be downsized and simplified while maintaining high energy efficiency. The cost of equipment can be reduced. Moreover, by setting it as such a structure, while being able to reduce the heat insulating material used for the heat exchanger for cold energy collection | recovery, the thickness of the heat insulating material 10 installed in the freezer 1 of a present Example is used for the conventional cold energy collection | recovery. It can be made thinner than the heat insulating material used in the heat exchanger for the car.

The air refrigerant refrigeration apparatus according to the second embodiment will be described with reference to FIGS. In the following second and third embodiments, detailed description of the same configurations as those of the first embodiment will be omitted.
Referring to FIG. 2, the air refrigerant refrigeration apparatus of the second embodiment has a discharge space 15 downstream of the discharge space 15 of the freezer 1 or between the freezer 1 and the compressor 3 in addition to the configuration of the first embodiment. The foreign matter removing filter 16 for removing the foreign matter existing in the air that has passed through is provided. The foreign matter removal filter 16 is arranged so as to cross the discharge space 15, and is configured such that air of about 35 ° C. heated in the discharge space 15 passes through this filter. In the figure, the foreign matter removal filter 16 is installed in the discharge space 15, but may be provided in the air discharge path 23 immediately after the air discharge port of the freezer 1. The foreign matter removing filter 16 removes the dust generated when the object 30 is cooled in the working space 11 and scattered in the storage.

According to the present embodiment, the dust scattered in the warehouse can be removed by the foreign matter removal filter 16, and the foreign matter can be prevented from flowing into the system of the refrigeration cycle. Can be prevented.
Further, in this embodiment, the foreign matter removal filter 16 can be used in an atmosphere at a substantially normal temperature (35 ° C. in this embodiment), so that the structure of the foreign matter removal filter 16 can be simplified and maintenance can be performed. Can be done easily. In maintenance, the foreign matter removal filter 16 is periodically or continuously cleaned, but the thermal load applied to the refrigeration space can be reduced during this cleaning.

FIG. 3 shows a configuration to which the second embodiment is applied. As shown in the figure, here, a roll filter 31 is used as the foreign matter removal filter 16. Further, a cleaning device 32 for cleaning the filter 31 is provided at one end of the roll filter 31. At this time, one end of the roll filter 31 may be provided outside the freezer 1 and the roll filter 31 may be cleaned by a cleaning device 32 provided outside the freezer as well.
Moreover, the pressure sensor 33 which detects the suction pressure of the compressor 2 is provided, and the action | operation of the roll filter 31 and the washing | cleaning apparatus 32 is controlled based on the detected compressor suction pressure. That is, when the compressor suction pressure is equal to or lower than a predetermined pressure set in advance, the roll filter 31 is wound up and the cleaning device 32 is operated at the same time.
This is because when dust is attached to the surface of the roll filter 31, the air flow path is narrowed, and the pressure on the compressor suction side is reduced. Therefore, by detecting this suction pressure, the filter 31 can be automatically wound and washed even when the filter is not completely clogged.

According to the present embodiment, by using the roll filter 31 as the foreign matter removal filter, the powder can be continuously removed.
Further, the cleaning device 32 can be downsized by using the roll filter 31. The reason will be described with reference to FIG. FIG. 4A is a side view of the refrigeration apparatus provided with the roll filter of the present embodiment, and FIG. 4B is a side view of the refrigeration apparatus provided with the fixed filter of the comparative example.
In this figure, the working space 11 is formed in a horizontally long shape, and a transport conveyor 13 is provided so as to penetrate the space. This configuration is described in Japanese Patent Laid-Open No. 11-63777, and this embodiment can be applied to this.
A front chamber 14a is provided on the upstream side of the working space 11 in the conveyor conveyance direction, and a rear chamber 14b is provided on the downstream side. The front chamber 14a and the rear chamber 14b have a communication part with outside air, and are provided for the purpose of maintaining a cooling atmosphere of the working space 11. A discharge space 15 is formed above the working space 11, and a foreign matter removal filter 31 is provided on the downstream side of the discharge space 15.

In the example provided with the fixed filter of FIG. 4B, a cleaning / maintenance inspection port 35 having the same size as the filter is required for cleaning the filter.
On the other hand, in the example provided with the roll filter of the present embodiment shown in FIG. 4A, the entire cleaning / maintenance can be performed by providing the cleaning device 35 in a part of the filter. 32 and the inspection port 35 can be reduced in size.

Further, FIG. 5 shows a configuration in which the second embodiment is applied. As shown in the figure, in addition to the foreign matter removal filter 16, a suction side filter 17 is provided on the suction side of the discharge space 15. The suction filter 17 preferably has a larger opening than the foreign matter removal filter 16. Further, the installation position of the suction-side filter 17 is set to a temperature range that is downstream of the working space 11 and upstream of the discharge space 15 or upstream of the discharge space 15 and below the freezing temperature of water. The air that has passed through the suction filter 17 flows into the discharge space 15 through the duct 18.
The suction filter 17 removes ice (including snow) generated in the working space 11.
According to the present embodiment, by installing the suction side filter 17 on the upstream side of the discharge space 15, it is possible to remove large snow and ice when the moisture load increases. Moreover, since there is a possibility that the foreign substance removal filter 16 alone will cause clogging with respect to the mixing of large-sized powder, the inflow of powder into the system can be prevented by two-stage filtering.

The air refrigerant refrigeration apparatus according to the third embodiment will be described with reference to FIGS.
First, referring to FIG. 6, the air refrigerant refrigeration apparatus of the present embodiment includes a hot water tank 37 that stores hot waste water 21 that has been heated by the primary cooler 5, and hot water waste water from the hot water tank 37 that is stored in the freezer 1. The structure is provided with a warm drainage supply path 39 for supplying to the water. The warm drainage supplied to the freezer 1 via the warm drainage supply path 39 is used for washing the freezer 1.
Moreover, it is good also as a structure which collect | recovers heat energy by heat-exchanging warm water and cleaning water as another structure. In this case, the warm waste water is cooled and can be used again for heat exchange of the primary cooler 5, and the supply amount to the primary cooler 5 is adjusted by the valve 38.

The primary cooler 5 has a function of raising the temperature of the cooling water up to about 80 ° C. by heat exchange with the high-temperature and high-pressure water from the compressor 3. Therefore, the hot water tank 37 can store hot water having a desired temperature in a temperature range up to 80 ° C. Of course, the temperature may be adjusted by mixing with cooling water such as tap water or well water.
According to this, heat that has been conventionally thrown away from the primary cooler 5 to the outside air is recovered by the hot water tank 37 and stored, thereby enabling effective use of the heat.
Generally, after the completion of the refrigeration apparatus, a cleaning process inside the freezer 1 is entered. Conventionally, hot water heated by a boiler was used in the cleaning process, but by adopting the configuration of the present embodiment, the exhaust heat from the primary cooler 5 is recovered and the obtained hot waste water is used after the end of work. By using this for cleaning the inside of the cabinet, the energy that has been heated by the conventional boiler can be reduced, and the energy efficiency can be improved.

Moreover, there exists a structure shown in FIG. This is used for the cleaning device 32 of the roll filter 31 shown in the second embodiment. As shown in the figure, the cleaning device 32 is provided with an injection nozzle 32a for injecting the warm waste water toward the lower surface of the filter, on the return path of the roll filter 31, that is, below the filter located on the lower side. A scraping blade 32b is provided at least on the rear side of the ejection nozzle 32a with respect to the transport direction. The scraping blade 32b is preferably provided before and after the spray nozzle 32a.
In this cleaning device 32, hot waste water is sprayed from the spray nozzle 32a during filter cleaning to remove the powder adhering to the filter surface, and the powder powder frozen and fixed on the filter surface is melted by the heat of the hot water drain. The filter surface is cleaned by scraping with the rear scraping blade 32b. Cleaning in this embodiment is performed continuously or intermittently.

  Conventionally, hot water obtained by heating tap water with a boiler was jetted from the jet nozzle 32a. However, as in this embodiment, the hot waste water obtained from the primary cooler 5 is used for filter washing, so that the hot water is washed from the other. It is not necessary to introduce water, and it is possible to reduce boiler heavy oil used for heating cleaning water, thus realizing water and energy savings.

  When applying an air refrigerant refrigeration apparatus that is friendly to the global environment and high in safety, the present invention can be a downsized and simplified apparatus while maintaining high energy efficiency. It can be effectively used for freezing technology in various industries including frozen food manufacturing technology in Japan.

It is a block diagram of the air refrigerant freezing apparatus which concerns on Example 1 of this invention. It is a block diagram of the air refrigerant freezing apparatus which concerns on Example 2 of this invention. It is the figure which applied Example 2 of FIG. It is a figure explaining the filter of FIG. 3, (A) is a side view of the freezing apparatus provided with the roll filter, (B) is a side view of the freezing apparatus provided with the fixed filter. It is the figure which applied Example 2 of FIG. 2, FIG. It is a block diagram of the air refrigerant freezing apparatus which concerns on Example 3 of this invention. It is the schematic of the filter washing | cleaning apparatus which concerns on Example 3 of this invention. It is a schematic block diagram of the conventional air refrigerant freezing apparatus.

Explanation of symbols

1 Freezer (freezer room)
2 expander 3 compressor 5 primary cooler 10 heat insulating material 11 working space 12 air jet 13 transport conveyor 15 discharge space 16 foreign matter removal filter 17 suction side foreign matter removal filter 22 cold heat absorption path 23 air discharge path 24 compressed air supply path 31 Roll filter 32 Cleaning device 32a Spray nozzle 32b Scraping blade 33 Pressure sensor 37 Hot water tank 39 Warm drainage route

Claims (6)

A freezing chamber that forms a freezing space, a compressor that aspirates and compresses the air in the freezing chamber, a primary cooler that cools the compressed air by heat exchange with a cooling fluid, and adiabatic expansion of the cooled compressed air An air refrigerant refrigeration apparatus having an expander and supplying the low-temperature air obtained by the expander to the freezer compartment to form the refrigeration space.
The freezing space is partitioned into two communicating spaces through a heat insulating material, one space is a working space for cooling the object to be cooled, and the other space is a discharge space for discharging the air used for cooling,
In the discharge space, a cold heat absorption path through which the primary cooled air passes through the primary cooler is provided, the cold heat absorption path is connected to the suction side of the expander,
An air refrigerant refrigeration apparatus, wherein air passing through the cold heat absorption path is cooled to a predetermined temperature by heat exchange with low-temperature air flowing from the working space and passing through the discharge space.   Foreign matter present in the air passing through the discharge space is removed downstream of the discharge space with respect to the flow direction of the air flowing into the discharge space from the working space, or between the freezer compartment and the compressor. The air refrigerant refrigeration apparatus according to claim 1, further comprising a foreign matter removing filter.   The foreign matter removing filter is a roll filter, a filter cleaning means is provided in a part of the roll filter, a pressure sensor for detecting the suction pressure of the compressor is provided, and the filter cleaning is performed based on the detected suction pressure. 3. The air refrigerant refrigeration apparatus according to claim 2, wherein the operation of the means is controlled. The filter cleaning means is installed below the roll filter,
A hot waste water injection means for injecting the hot waste water obtained by the primary cooler from below with respect to the filter surface; and at least a rear side of the hot waste water injection means with respect to the moving direction of the roll filter; 4. The air refrigerant refrigeration apparatus according to claim 3, further comprising scraping means for scraping off foreign matter adhering to the roll filter.   The suction side filter having a larger opening than the foreign matter removal filter is provided upstream or upstream of the discharge space to remove foreign matter and ice in the low temperature air that has passed through the working space. Or the air refrigerant freezing apparatus of 3.   A hot water tank for storing the hot waste water obtained by the primary cooler; and a hot waste water supply path for supplying the hot waste water in the hot water tank to the freezer compartment. The hot waste water is used for washing the freezer compartment. 6. The air refrigerant refrigeration apparatus according to claim 1, wherein the air refrigerant refrigeration apparatus is used.

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