Cooling device and method for cleaning the cooling device

Abstract

The present invention provides a cooling device that can suitably clean a microchannel heat exchanger without using detergent. [Solution] The cooling device 1 includes a heat exchange section 130, which is a microchannel heat exchanger that cools the air circulating inside the chamber; a fan 20 for taking in the air inside the chamber that has been cooled to high humidity for food and circulating it inside the chamber; an adjustment section 50 that maintains a state in which moisture adheres to the heat transfer surface of the heat exchange section by adjusting the rotation speed of the fan; and a cleaning section 90 for cleaning the heat exchange section. The cleaning section sprays cleaning water containing fine bubbles onto the microchannel heat exchanger.

Description

Technical Field

[0001] The present invention relates to a cooling device and a cleaning method for the cooling device.

Background Art

[0002] In recent years, in the field of refrigeration equipment, with the adoption of a microchannel heat exchanger as a heat exchanger, miniaturization and high performance of the cooling device have been expected.

[0003] In relation to this, for example, Patent Document 1 below discloses a technique for cooling food in a storage at a low temperature and high humidity using a microchannel heat exchanger as a heat exchanger.

[0004] The low-temperature and high-humidity environment is expected to be used not only for storage of agricultural products but also for cooling and aging processes in food production. Therefore, when applied to the field of agricultural products and food, it is necessary to improve the hygiene of the entire system.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Since the above-mentioned microchannel heat exchanger has a fine fin coil structure, it is difficult to clean. To clean the microchannel heat exchanger, for example, a method of draining water to the microchannel heat exchanger can be considered.

[0007] However, since the microchannel heat exchanger has a fine fin coil structure, water stays in the microchannel heat exchanger due to the surface tension of water, so water does not flow, and only cleaning by the substance diffusion effect on the retained water can be expected, and it is difficult to clean properly.

[0008] On the other hand, using detergents is another possible method to improve the cleaning effect on microchannel heat exchangers.

[0009] However, in foam cleaning using detergent, the viscous nature of the detergent foam makes it difficult for the cleaning foam to penetrate the fine fin coils of the microchannel heat exchanger. Furthermore, rinsing with water is necessary to remove the detergent, but due to the fine fin coil structure of the microchannel, complete removal of the detergent foam that has entered the fin coils with water is difficult. In addition, residual detergent can become highly concentrated and cause corrosion of the equipment. Moreover, detergent blown away by the fan may scatter inside the chamber, requiring an internal cleaning mechanism to remove it. For these reasons, cleaning with detergent is undesirable.

[0010] The present invention was made to solve the above problems, and aims to provide a cooling device and cleaning method that can suitably clean a microchannel heat exchanger without using detergent. [Means for solving the problem]

[0011] The cooling device according to the present invention, which achieves the above objective, is a cooling device for cooling food inside a storage chamber to high humidity, and comprises: a heat exchange section which is a microchannel heat exchanger that cools the air circulating inside the storage chamber; a fan for taking in the air inside the storage chamber that has been cooled to high humidity and circulating it inside the storage chamber; an adjustment section which maintains a state in which moisture adheres to the heat transfer surface of the heat exchange section without using a water spraying device by adjusting the rotation speed of the fan; and a cleaning section which cleans the heat exchange section, wherein the cleaning section sprays cleaning water containing fine bubbles.

[0012] Furthermore, the present invention, which achieves the above objective, is a cleaning method for a cooling device that cools food inside a storage unit to high humidity, wherein the cooling device comprises a heat exchange section which is a microchannel heat exchanger that cools the air circulating inside the storage unit, a fan for taking in the air inside the storage unit that has been cooled to high humidity and circulating it inside the storage unit, an adjustment section which maintains a state in which moisture adheres to the heat transfer section of the heat exchange section without using a water spraying device by adjusting the rotation speed of the fan, and a cleaning section which cleans the heat exchange section, wherein after the operation of the cooling device is stopped, the cleaning method comprises a water spraying step in which the cleaning section sprays cleaning water containing fine bubbles onto the heat exchange section, a cleaning step in which the spraying of the cleaning water is stopped and the cleaning water is held in the heat exchange section for a predetermined time, and a cleaning water removal step in which the fan blows away the cleaning water held in the heat exchange section. [Effects of the Invention]

[0013] According to the cooling device and cleaning method described above, the cleaning unit sprays cleaning water containing fine bubbles, allowing for effective cleaning through a jack-up effect where the fine bubbles lift and remove dirt. Therefore, it is possible to provide a cooling device and cooling method that can effectively clean a microchannel heat exchanger without using detergent. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic front view showing a cooling device according to an embodiment of the present invention. [Figure 2] This is a schematic diagram showing the configuration of the heat exchange section of the cooling device according to this embodiment. [Figure 3] This is a schematic side view showing the cooling device according to this embodiment. [Figure 4A] This is a plan view showing the sample plate used in evaluation test 1. [Figure 4B] This is a front view showing the three stacked sample plates in Evaluation Test 2. [Figure 5] This graph shows the relationship between wavelength and dye absorbance. [Figure 6]It is a graph showing the relationship between concentration and absorbance. [Figure 7] It is a graph showing the relationship between immersion time and elution amount in Evaluation Test 1. [Figure 8] It is a graph showing the dirt removal rate in Evaluation Test 2.

Mode for Carrying Out the Invention

[0015] The cooling device 1 according to an embodiment of the present invention will be described while referring to FIGS. 1 and 2. In the description of the drawings, the same reference numerals are assigned to the same elements, and duplicate descriptions are omitted. The dimensional ratios in the drawings are exaggerated for the convenience of explanation and may be different from the actual ratios.

[0016] FIG. 1 is a schematic front view showing the cooling device 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of the heat exchange unit 130 of the cooling device 1 according to the present embodiment. FIG. 3 is a schematic side view showing the cooling device 1 according to the present embodiment.

[0017] As shown in FIG. 1, the cooling device 1 includes a generating unit 110, a housing 80, and a cleaning unit 90. The cooling device 1 is a device for cooling food F such as vegetables at high humidity. Hereinafter, each component will be described.

[0018] As shown in FIG. 1, the generating unit 110 includes a fan 20, a pre-filter 70, a heat exchange unit 130, a condensing unit 140, an adjusting unit 50, and a casing 60. The fan 20, the pre-filter 70, and the heat exchange unit 130 are configured to be covered by the casing 60.

[0019] The housing 80 is composed of a heat insulating wall, and the inside of the housing 80 is used as a storage for cooling food F such as vegetables at high humidity.

[0020] The generating unit 110 generates cooled air while maintaining high humidity by bringing the moisture adhering to the heat exchange unit 130, which is an evaporator, into contact with the air inside the housing 80.

[0021] As shown in Figure 1, the fan 20 is located on the rear side (left side in Figure 1), which is the air inlet side of the heat exchange section 130. The fan 20 draws in the air inside the housing 80 after the food F has been cooled to high humidity and blows it toward the pre-filter 70 and the heat exchange section 130. In other words, the fan 20 takes in the air after the food F has been cooled to high humidity from the left side as shown in Figure 1 and blows it toward the right side (see arrow V1 in Figure 1). Here, high humidity cooling means, for example, cooling at a humidity of 80% or higher. By arranging the fan to blow air horizontally in this way, water can be suitably stored in the heat exchange section 130.

[0022] The condensing unit 140 includes a compressor and a condenser (not shown). The cooling device 1 is called a "direct expansion cooling method" and is connected by refrigerant piping. It expands the refrigerant near the space to be cooled to perform heat exchange and directly cool the air inside the housing 80.

[0023] The pre-filter 70 is positioned between the fan 20 and the heat exchange unit 130. The pre-filter 70 collects dust and straightens the air drawn into the casing 60. For example, a non-woven fabric filter can be used as the pre-filter 70. By providing the pre-filter 70 in this way, dust is collected from the air drawn into the casing 60, which helps to prevent the heat exchange unit 130 from becoming contaminated during cooling operation.

[0024] The heat exchange unit 130 cools the air circulating in the chamber by exchanging heat between the refrigerant supplied by the condensing unit 140 and the air circulating inside the chamber. The heat exchange unit 130 is a microchannel heat exchanger. The configuration of the heat exchange unit 130 will be described below with reference to Figure 2. Figure 2 is a view of the heat exchange unit 130 from the pre-filter 70 side.

[0025] As shown in Figure 2, the heat exchange section 130 includes two refrigerant headers 131 and 132, a plurality of heat transfer tubes 133 arranged vertically and connecting the refrigerant headers 131 and 132, and fins 134 disposed between the heat transfer tubes 133 so as to be in contact with the heat transfer tubes 133.

[0026] The air inside the chamber is blown by the fan 20 from the rear side (left side in Figure 1) to the front side (right side in Figure 1) of the heat exchange section 130 and flows between the fins 134. Meanwhile, the refrigerant supplied from the condensing unit 140 flows in from the refrigerant header 131, which is the refrigerant inlet side, flows through the refrigerant flow path formed inside the heat transfer tubes 133, and flows to the refrigerant header 132, which is the refrigerant outlet side.

[0027] The refrigerant in the refrigerant flow path exchanges heat with the air inside the chamber via the heat transfer tubes 133 and fins 134.

[0028] The surface of the fins 134 is configured as a heat transfer element that transmits the cold heat of the refrigerant to the air inside the chamber. The surface of the fins 134 is maintained in a state where moisture contained in the air inside the chamber and the food F adheres to it by the adjustment unit 50. The fins 134 are arranged horizontally.

[0029] With the heat exchange section 130 configured in this way, condensation water adheres to the horizontally arranged fins 134 due to the difference in dew point temperature between the temperature of the fins 134 when heat is transferred from the refrigerant and the temperature of the air inside the chamber that comes into contact with them. Here, because the pitch of the fins 134 is narrow and surface tension is generated, the condensation water adheres to and is retained on the fins 134. For this reason, the air blown out from the heat exchange section 130 maintains a high humidity state. However, if the air velocity passing through the heat exchange section 130 is too fast, the condensation water will scatter, so it is preferable to appropriately control the rotation speed of the fan 20.

[0030] The adjustment unit 50 maintains a state in which moisture contained in the air inside the oven and the food F adheres to the heat exchange unit 130.

[0031] The casing 60 houses the fan 20, the water spraying section 91 of the cleaning section 90, and the heat exchange section 130. With this configuration, by housing the fan 20, the water spraying section 91 of the cleaning section 90, and the heat exchange section 130 inside the casing 60, dirt and foreign matter inside the housing 80 are prevented from entering the heat exchange section 130 during cooling operation, and cleaning water is prevented from splashing into the housing 80 when cleaning the heat exchange section 130.

[0032] As shown in Figure 1, the generating unit 110 includes a first path 210 through which refrigerant flows from the condenser to the heat exchange unit 130, a second path 220 through which refrigerant flows from the heat exchange unit 130 to the compressor, and a third path 230 that connects the compressor (discharge side) and the second path 220 and supplies the heat generated by the compressor to the second path 220.

[0033] An expansion valve 240 is provided in the first path 210. The expansion valve 240 lowers the temperature of the refrigerant by expanding the refrigerant that has been compressed in the compressor, liquefied in the condenser, and flowed into the expansion valve 240.

[0034] A first control valve 250 is provided in the second path 220. The first control valve 250 adjusts the pressure inside the heat exchange section 130 so that the evaporation pressure of the refrigerant inside the heat exchange section 130 does not fall below a specified value, and adjusts the evaporation temperature of the refrigerant inside the heat exchange section 130.

[0035] A second control valve 260 is provided in the third path 230. The second control valve 260 adjusts the amount of heat supplied to the second path 220. This allows the desired amount of heat from the refrigerant compressed by the compressor through the third path 230 to be supplied to the refrigerant gas in the second path 220, thereby controlling the degree of superheating of the refrigerant gas flowing through the second path 220.

[0036] The cleaning unit 90 cleans the heat exchange unit 130, which is a microchannel heat exchanger. As shown in Figures 1 and 3, the cleaning unit 90 includes a water spraying unit 91, a supply line 92 for supplying cleaning water containing fine bubbles (hereinafter sometimes referred to as fine bubble water or FB water), and a fine bubble generating unit 93 for generating fine bubbles.

[0037] The water spraying unit 91 sprays fine bubble water onto the heat exchange unit 130. Specifically, as shown in Figure 1, the water spraying unit 91 is positioned on the upper side of the heat exchange unit 130 so that fine bubble water can be sprayed from the top of the heat exchange unit 130. With this configuration, the fine bubble water sprayed from the water spraying unit 91 spreads evenly over the top of the heat exchange unit 130, then flows downwards and permeates the entire heat exchange unit 130. As a result, the cleaning efficiency of the heat exchange unit 130 is improved.

[0038] As shown in Figure 1, the water spraying unit 91 is installed so that fine bubble water is sprayed diagonally downward to the right in the horizontal direction. The angle of inclination with respect to the horizontal direction is not particularly limited, but is, for example, 20 degrees or less. With this configuration, the fine bubble water is sprayed over a wide area at a gentle angle and supplied evenly to the entire heat exchange unit 130. As a result, dirt and deposits on the heat exchange unit 130 can be efficiently removed, and the cleaning efficiency of the cleaning unit 90 is improved.

[0039] As shown in Figure 3, multiple water spraying units 91 (four in Figure 3) are provided in the width direction of the heat exchange unit 130. By providing multiple water spraying units 91 in the width direction of the heat exchange unit 130 in this way, the spraying range of the fine bubble water from the water spraying units 91 is widened, and the distribution of the fine bubble water becomes more uniform, allowing the heat exchange unit 130 to be cleaned efficiently and over a wide area.

[0040] The pressure of the fine bubble water sprayed from the water spraying unit 91 is not particularly limited, but is preferably 0.2 to 0.4 MPa. By setting it within this range, the strength and spread of the spray can be optimized according to the usage environment and the size of the heat exchange unit 130, which is the object to be cleaned, and unevenness in the spray can be suppressed. As a result, a consistent cleaning effect on the heat exchange unit 130 can be achieved in various situations, and an improvement in cleaning performance can be expected.

[0041] In this embodiment, the fan 20, the water spraying section 91 of the cleaning section 90, and the heat exchange section 130 are arranged in that order from the side where horizontal air is taken in (left side in Figure 1). With this configuration, dirt inside the housing 80 flows into the heat exchange section 130 along with the air by the fan 20, so the dirt in the heat exchange section 130 is concentrated on the fan 20 side, i.e., the air inlet side. By arranging the cleaning section 90 between the fan 20 and the heat exchange section 130, the cleaning efficiency of the heat exchange section 130 can be improved.

[0042] The supply line 92 is arranged to connect the fine bubble generation unit 93 and the water spraying unit 91. The supply line 92 is provided with a control valve 92V for adjusting the flow rate.

[0043] The fine bubble generating unit 93 can generate fine bubbles. The fine bubble generating unit 93 is connected to tap water piping (not shown) and can generate fine bubbles in tap water to produce fine bubble water. The fine bubbles used can contain any number of microbubbles, but it is preferable that 50% or more are ultrafine bubbles with a diameter of less than 1 μm. By including 50% or more ultrafine bubbles, the jack-up effect that lifts dirt and cleans it is more effectively exhibited, and the cleaning performance is further improved. In addition, by providing the fine bubble generating unit 93, the necessary amount of fine bubbles can be generated when cleaning the heat exchange unit 130.

[0044] The control valve 92V and the fine bubble generation unit 93 are controlled by the control unit 30, as shown in Figures 1 and 2.

[0045] Next, a cleaning method for the cooling device 1 according to this embodiment will be described. The cleaning method includes a moisture removal step, a water spraying step, a cleaning step, and a cleaning water removal step, after the cooling device 1 has been shut down.

[0046] In the moisture removal step, during the cooling operation of the cooling device 1, moisture adhering to the surface of the fins 134 of the heat exchange section 130 is blown away by the fan 20.

[0047] For example, if there is no moisture removal step, moisture generated during the cooling operation will remain attached to the surface of the fins 134 of the heat exchange section 130. As a result, the fine bubble water sprayed in the water spraying step will not efficiently penetrate the heat exchange section 130, and the jack-up effect cannot be obtained favorably. In contrast, in the cleaning method of the cooling device 1 according to this embodiment, since there is a moisture removal step, the water attached to the heat exchange section 130 is removed by the fan 20, making it easier for the cleaning water to efficiently penetrate the heat exchange section 130, and thus a jack-up effect can be obtained favorably.

[0048] In the watering step, the watering unit 91 of the washing unit 90 sprays fine bubble water onto the heat exchange unit 130. The duration of the watering step is not particularly limited, but can be, for example, 10 minutes or less. By setting the duration of the watering step to 10 minutes, an appropriate amount of water can be supplied to the heat exchange unit 130.

[0049] In the cleaning step, after stopping the spraying of fine bubble water, the fine bubble water is retained in the heat exchange section 130 for a predetermined time. The duration of the cleaning step is not particularly limited, but can be, for example, 10 to 30 minutes. By making the cleaning step duration 10 minutes or longer, the jack-up effect of the fine bubbles is maximized, allowing dirt in the heat exchange section 130 to be efficiently removed without adhering, thereby improving the cleaning performance of the heat exchange section 130. Conversely, by making the cleaning step duration 30 minutes or less, a balance is achieved between cleaning time and cleaning performance, improving the operating efficiency of the equipment.

[0050] In the cleaning water removal step, the fan 20 blows away the cleaning water containing the dirt from the cleaning step that is held in the heat exchange section 130.

[0051] Furthermore, it is preferable that the output of the fan 20 in the moisture removal step and the washing water removal step described above be 1.2 times or more than that of the cooling device 1 during normal operation. By setting the output of the fan 20 to 1.2 times or more than that of the cooling device 1 during normal operation, moisture adhering to the surface of the fins 134 of the heat exchange section 130 during the cooling operation of the cooling device 1 and fine bubble water held in the heat exchange section 130 during the washing step can be effectively blown away.

[0052] Next, we will describe the effects of the cleaning unit 90 of the cooling device 1 according to this embodiment, while explaining two evaluation tests.

[0053] <First Evaluation Test> First, let's explain the first evaluation test. As shown in Figure 4A, a sample of stain R was prepared by mixing polyvinyl alcohol (PVA) with Red No. 102. Then, 100 μl (assuming 100 mg) of the stain R sample prepared above was spread onto a stainless steel plate P in a 20 mm x 20 mm area to prepare two sample plates.

[0054] Of the sample plates prepared above, one was placed in a 100ml beaker containing 50ml of distilled water, and the other was placed in a 100ml beaker containing 50ml of fine bubble water, and left to stand for a specified time.

[0055] Then, distilled water and fine bubble water were collected, and their absorbance at 510 nm was measured using a spectrophotometer. This was because, as shown in Figure 5, red 102 shows a peak value at a wavelength of 510 nm.

[0056] Then, based on the graph showing the relationship between concentration and absorbance shown in Figure 6, the concentration of Red No. 102 in distilled water and fine bubble water was calculated. In this case, a higher absorbance is considered to indicate that more Red No. 102 was eluted, and thus the cleaning performance was judged to have improved.

[0057] Then, based on the concentration of Red No. 102 in distilled water and fine bubble water, the amount of Red No. 102 eluted from each was calculated and converted into cleaning capacity. The results are shown in Figure 7. In Figure 7, the horizontal axis represents immersion time, and the vertical axis represents the amount of Red No. 102 eluted. In Figure 7, the solid line shows the results for fine bubble water, and the dotted line shows the results for distilled water. From Figure 7, it can be seen that the amount of Red No. 102 eluted is greater in fine bubble water than in distilled water, indicating that cleaning performance is improved by using fine bubble water. Furthermore, based on the slopes of the solid and dashed lines, it was found that the cleaning efficiency of fine bubble water is approximately 33% higher than that of distilled water.

[0058] <Second Evaluation Test> Next, the second evaluation test will be described. Similar to the first evaluation test, a sample of contamination R was prepared by mixing polyvinyl alcohol (PVA) with Red No. 102. Then, as shown in Figure 4B, 100 μl (assuming 100 mg) of the contamination R sample prepared above was applied to a 20 mm x 20 mm area on a stainless steel plate P. Spacers S were placed between the stainless steel plates P so that the distance between them was 1 mm, and two sample plates (simulating a microchannel heat exchanger: in Figure 4B, a total of 4 plates consisting of 3 plates P with the contamination R sample applied and 1 plate P without the contamination R sample applied) were prepared.

[0059] Of the sample plates prepared above, one was placed in a 200ml beaker containing 150ml of distilled water, and the other was placed in a 200ml beaker containing 150ml of fine bubble water, and left to stand for 10 minutes.

[0060] Subsequently, the amount of Red No. 102 eluted was calculated using the same procedure as in the first evaluation test described above, and converted into cleaning capacity. The results are shown in Figure 8. In Figure 8, the horizontal axis represents distilled water or fine bubble water, and the vertical axis represents the dirt removal rate over 10 minutes. From Figure 8, it can be seen that fine bubble water has a higher dirt removal rate than distilled water. Specifically, it was found that the dirt removal rate of fine bubble water is approximately 11% higher than that of distilled water.

[0061] As described above, the cooling device 1 according to this embodiment is a cooling device 1 for high-humidity cooling of food F inside a storage chamber, and includes a heat exchange section 130 which is a microchannel heat exchanger that cools the air circulating inside the chamber, a fan 20 for taking in the air inside the chamber that has been cooled to high humidity with food F and circulating it inside the chamber, an adjustment section 50 which maintains a state in which moisture adheres to the heat transfer surface of the heat exchange section 130 without using a water spraying device by adjusting the rotation speed of the fan 20, and a cleaning section 90 for cleaning the heat exchange section 130. The cleaning section 90 sprays cleaning water containing fine bubbles. With the cooling device 1 configured in this way, since the cleaning section 90 sprays cleaning water containing fine bubbles, it is possible to suitably clean by a jack-up effect in which dirt is lifted up by the fine bubbles and cleaned.

[0062] Furthermore, the cooling device 1 has a casing 60 that houses the fan 20, the cleaning unit 90, and the heat exchange unit 130. With the cooling device 1 configured in this way, by housing the fan 20, the water spraying unit 91 of the cleaning unit 90, and the heat exchange unit 130 inside the casing 60, it is possible to prevent dirt and foreign matter from entering the heat exchange unit 130 from the housing 80 during cooling operation, and to prevent cleaning water from splashing into the housing 80 when cleaning the heat exchange unit 130.

[0063] Furthermore, the cooling device 1 also includes a fine bubble generating unit 93 that generates fine bubbles. With the cooling device 1 configured in this way, the necessary amount of fine bubbles can be generated when cleaning the heat exchange unit 130.

[0064] Furthermore, the cleaning method for the cooling device 1 according to this embodiment is a cleaning method for the cooling device 1 that cools food F inside the storage chamber at high humidity, and includes a watering step in which, after the operation of the cooling device 1 is stopped, the cleaning unit 90 sprays cleaning water containing fine bubbles onto the heat exchange unit 130; a cleaning step in which the spraying of cleaning water is stopped and the cleaning water is held in the heat exchange unit 130 for a predetermined time; and a cleaning water removal step in which the fan 20 blows away the cleaning water held in the heat exchange unit 130. With this cleaning method, since the cleaning unit 90 sprays cleaning water containing fine bubbles, the cleaning can be suitably performed by a jack-up effect in which dirt is lifted up by the fine bubbles and cleaned.

[0065] Furthermore, the cleaning method for the cooling device 1 according to this embodiment further includes a moisture removal step in which moisture adhering to the heat transfer section of the heat exchange section 130 is blown away by the fan 20 before the water spraying step. With this cleaning method, by removing the water adhering to the heat exchange section 130 during cooling operation with the fan 20, the cleaning water can penetrate the heat exchange section 130 more efficiently, and the jack-up effect can be obtained more favorably.

[0066] Furthermore, the cleaning step is performed for 10 to 30 minutes. With this cleaning method, by making the cleaning step time 10 minutes or more, the jack-up effect of the fine bubbles is maximized, and dirt in the heat exchange section 130 is efficiently removed without adhering, thereby improving the cleanability of the heat exchange section 130. Also, by making the cleaning step time 30 minutes or less, a balance is achieved between cleaning time and cleanability, and the operating efficiency of the equipment is also improved.

[0067] Furthermore, the output of the fan 20 during the moisture removal step and the cleaning water removal step is 1.2 times or more than that during normal operation of the cooling device 1. This cleaning method allows for the effective blowing away of moisture adhering to the surface of the fins 134 of the heat exchange section 130 during the cooling operation of the cooling device 1, and cleaning water held in the heat exchange section 130 during the cleaning step.

[0068] It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the claims.

[0069] For example, in the embodiment described above, there is a fine bubble generating unit 93 that generates fine bubbles, but the present invention also includes a configuration in which the fine bubble generating unit 93 is not provided, and washing water containing pre-prepared fine bubbles is sprayed from the water spraying unit 91.

[0070] Furthermore, although the above-described embodiment includes a casing 60 that houses the fan 20, the cleaning unit 90, and the heat exchange unit 130, the casing 60 may be omitted.

[0071] Furthermore, although the above-described embodiment includes a water removal step before the watering step, the present invention also includes a cleaning method that does not include a water removal step. [Explanation of symbols]

[0072] 1 cooling device, 20 fans, 130 heat exchange section, 50 adjustment section, 60 casings, 90 Cleaning section, 91 Sprinkler unit, 93 Fine bubble generation section, 110 Generating part, F Food.

Claims

1. A cooling device for cooling food inside a storage area at high humidity, The heat exchange section is a microchannel heat exchanger that cools the air circulating inside the chamber, A fan for taking in the air inside the storage unit, which has been cooled with high humidity for the food, and circulating it inside the storage unit, An adjustment unit that maintains a state in which moisture adheres to the heat transfer part of the heat exchange unit without using a watering device by adjusting the rotation speed of the aforementioned fan, It has a cleaning unit for cleaning the heat exchange unit, The aforementioned cleaning unit is a cooling device that sprays cleaning water containing fine bubbles.

2. The cooling device according to claim 1, further comprising a casing for housing the fan, the cleaning unit, and the heat exchange unit.

3. The cooling device according to claim 1 or 2, further comprising a bubble generating unit for generating the fine bubbles.

4. A method for cleaning a cooling device that cools food inside a storage room at high humidity, The cooling device, The heat exchange section is a microchannel heat exchanger that cools the air circulating inside the chamber, A fan for taking in the air inside the storage unit, which has been cooled with high humidity for the food, and circulating it inside the storage unit, An adjustment unit that maintains a state in which moisture adheres to the heat transfer part of the heat exchange unit without using a watering device by adjusting the rotation speed of the aforementioned fan, It has a cleaning unit for cleaning the heat exchange unit, After the cooling device has stopped operating, The cleaning unit includes a water spraying step in which it sprays cleaning water containing fine bubbles onto the heat exchange unit, A cleaning step which involves stopping the spraying of the cleaning water and holding the cleaning water in the heat exchange section for a predetermined time, A method for cleaning a cooling device, comprising a step of removing cleaning water by blowing away the cleaning water held in the heat exchange section by the fan.

5. Before the aforementioned watering step, The method for cleaning a cooling device according to claim 4, further comprising a moisture removal step of blowing away the moisture adhering to the heat transfer portion of the heat exchange portion with the fan.

6. The method for cleaning a cooling device according to claim 4 or 5, wherein the cleaning step is performed for 10 to 30 minutes.

7. The method for cleaning a cooling device according to claim 5, wherein the output of the fan in the moisture removal step and the cleaning water removal step is 1.2 times or more than that of the cooling device during normal operation.

Images