WO2014076362A1 - Procédé de réfrigération et équipement de réfrigération - Google Patents

Procédé de réfrigération et équipement de réfrigération Download PDF

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Publication number
WO2014076362A1
WO2014076362A1 PCT/FI2013/000044 FI2013000044W WO2014076362A1 WO 2014076362 A1 WO2014076362 A1 WO 2014076362A1 FI 2013000044 W FI2013000044 W FI 2013000044W WO 2014076362 A1 WO2014076362 A1 WO 2014076362A1
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WO
WIPO (PCT)
Prior art keywords
air
space
refrigerated
refrigeration
freezer
Prior art date
Application number
PCT/FI2013/000044
Other languages
English (en)
Inventor
Kari KANTOLUOTO
Pentti RYTKÖNEN
Orvo Backman
Original Assignee
Kylmäveräjä Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FI20120384A external-priority patent/FI124690B/fi
Application filed by Kylmäveräjä Oy filed Critical Kylmäveräjä Oy
Priority to EP13854493.7A priority Critical patent/EP2920530A4/fr
Publication of WO2014076362A1 publication Critical patent/WO2014076362A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
    • F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
    • F24F3/14—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D17/00—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces
    • F25D17/04—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating air, e.g. by convection
    • F25D17/042—Air treating means within refrigerated spaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D17/00—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces
    • F25D17/04—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating air, e.g. by convection
    • F25D17/06—Arrangements for circulating cooling fluids; Arrangements for circulating gas, e.g. air, within refrigerated spaces for circulating air, e.g. by convection by forced circulation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D21/00—Defrosting; Preventing frosting; Removing condensed or defrost water
    • F25D21/04—Preventing the formation of frost or condensate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/22—Means for preventing condensation or evacuating condensate
    • F24F2013/221—Means for preventing condensation or evacuating condensate to avoid the formation of condensate, e.g. dew
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D2317/00—Details or arrangements for circulating cooling fluids; Details or arrangements for circulating gas, e.g. air, within refrigerated spaces, not provided for in other groups of this subclass
    • F25D2317/04—Treating air flowing to refrigeration compartments
    • F25D2317/041—Treating air flowing to refrigeration compartments by purification
    • F25D2317/0411—Treating air flowing to refrigeration compartments by purification by dehumidification
    • F25D2317/04111—Control means therefor

Definitions

  • the object of the invention is a refrigeration method for refrigerating a space, such as a freezer space, freezing space, refrigerated space, store space or other cold space, according to which method the space is refrigerated by conducting refrigerated cooling air into the space.
  • Cold storage and deep-freeze warehouses are commonly used in the food industry and in grocery stores, as many foods are easily perishable. That is why many foods are frozen already at the production stage and are kept frozen after that during storage and distribution so that their temperature does not exceed -18°C. That is why industrial and commercial premises must accommodate a high number of different freezer spaces.
  • Known deep-freeze warehouses for foods or other products to be kept refrigerated are normally spaces where the fans and cooling radiators of the refrigeration equipment are located inside the freezer space, usually on the wall of the deep-freeze warehouse, and the condensers are located outside the freezer space.
  • a problem identified with known deep-freeze warehouses is that when the access door of the freezer space is opened even for just a moment, part of the cold air in the freezer space escapes due to temperature differences/the differences in temperature and warmer air flows into the freezer space from outside. This happens even if the access door of the freezer space opens up into a cool space with a temperature of +5°C or into a room space with a temperature of +24°C. Depending on how often the access door is opened, the temperature in known freezer spaces can therefore rise by up to approx. 5°- 6°C, i.e. reaching up to -12°C. A temperature rise of this magnitude, even if temporary, may have a detrimental effect on the quality of the goods to be stored.
  • freezer cabinets or freezer boxes and similar refrigerated spaces are often fully open.
  • the temperature variations in the freezer space and refrigerated space also lead to the compressors of the refrigeration equipment starting up to bring the temperature of the freezer space to a sufficiently low level.
  • the compressors starting up more frequently than necessary is not beneficial for the durability of the refrigeration equipment.
  • the warm air flowing into the freezer space when the access door is opened further leads, at the same time, to the volume of the air contained in the freezer space diminishing as it cools. A vacuum is then created in the freezer space, sucking in new warm air into the freezer space from outside of it.
  • the frost and ice built up in the freezer space can only be removed by defrosting the freezer space regularly. When defrosting the freezer space, it must first be cleared temporarily. Then the freezer space is heated from the temperature of -20°C to the temperature of +20°C, dried, cleaned, cooled again to the temperature of -20°C and refilled. These operations require a considerable amount of non-productive work and time. Heating and re-refrigerating the freezer space consumes a lot of costly energy.
  • the purpose of this invention is to create a refrigeration method for freezer spaces and other refrigerated spaces that overcomes the above-mentioned drawbacks. Furthermore, the purpose of the invention is to create a refrigeration method for a freezer space and refrigerated space that makes it possible to create, in the freezer space and refrigerated space, such conditions that as little as possible moisture enters and/or ice builds up in the freezer space or refrigerated space, in which case the freezer space or refrigerated space does not necessarily need to be defrosted at all or defrosting is needed extremely rarely.
  • the cooling air is dried and refrigerated in one or several stages, where drying takes place first and then refrigeration so that the cooling air temperature remains above the dew point.
  • the dried and refrigerated cooling air is conducted into the space to be refrigerated or is mixed with the circulating air that refrigerates the space to be refrigerated.
  • the dried and refrigerated cooling air is conducted into the space to be refrigerated so that an overpressure is created in the space to be refrigerated.
  • Dried air is conducted or blown into the freezer space or refrigerated space to reduce the moisture of the air in the freezer space and to create an overpressure in the freezer space.
  • Air can be blown into the freezer space or refrigerated space from a space outside the freezer space, such as a refrigerated space, and moisture is removed from the air before conducting it into the freezer space.
  • a space outside the freezer space such as a refrigerated space
  • Another possibility is to dry the air in the freezer space so that air is conducted from the freezer space into the dryer, from where the dried air is blown back into the freezer space.
  • the air in the freezer space or refrigerated space is circulated so that air is conducted from the freezer space into the refrigeration unit located outside the freezer space, from where the refrigerated air is blown back into the freezer space in a refrigerated state.
  • the object of the invention is furthermore a freezer space arrangement that includes a freezer space and refrigeration equipment for refrigerating the freezer space.
  • the freezer space arrangement according to the invention is characterised in that an air dryer is used jointly with the freezer space to reduce the moisture content of the air contained in the freezer space.
  • An air dryer and a fan for conducting the air coming from the air dryer into the freezer space and for creating an overpressure in the freezer space have been provided in connection with the freezer space or refrigerated space.
  • the air dryer is connected to the space outside the freezer space, such as a refrigerated space, so that dried air can be blown from the space outside the freezer space into the freezer space to reduce the moisture in the freezer space and to create an overpressure in the freezer space.
  • a refrigerated space such as a refrigerated space
  • Outside the freezer space is an air dryer and a fan for circulating the air contained in the freezer space through the air dryer back into the freezer space.
  • a cooling air channel and a refrigeration unit connected to it, including a fan and a cooling radiator, and, for refrigerating the air in the freezer space, the air in the freezer space has been arranged to circulate through the cooling radiator back into the freezer space.
  • a cooling air channel and a refrigeration unit through which the circulation air that refrigerates the freezer space has been arranged to circulate, and the air dryer has been connected, with a dry air channel, to the cooling air channel to mix the dry air with the circulation air that refrigerates the freezer space and to create an overpressure in the freezer space.
  • the object of the invention is furthermore refrigeration equipment for refrigerating a space, such as a freezer space, freezing space, refrigerated space, store space or other cold space, which refrigeration equipment includes a cooling member, such as a cooling radiator, for refrigerating the cooling air and a fan for conducting the refrigerated air into the space.
  • refrigeration equipment includes a cooling member, such as a cooling radiator, for refrigerating the cooling air and a fan for conducting the refrigerated air into the space.
  • the refrigeration equipment includes at least one air dryer for drying the cooling air and at least one cooling member for refrigerating the cooling air that has first been dried with the air dryer.
  • the refrigeration equipment includes one or several combinations consisting of an air dryer and cooling member, which can be placed to function one after the other.
  • the refrigeration equipment includes a fan for conducting the cooling air dried by the air dryer and refrigerated by the cooling member into the space to be refrigerated or into the circulation air that refrigerates it.
  • the refrigeration equipment includes a fan for conducting the cooling air dried by the air dryer and refrigerated by the cooling member into the space to be refrigerated so that an overpressure is created in the space to be refrigerated.
  • the freezer space or refrigerated space is kept at a slight overpressure with the air produced using the dryer, which air has been dried, i.e. its moisture content has been lowered.
  • no moisture can enter into the freezer space or refrigerated space, which would build up ice or frost, which means that the freezer space or refrigerated space does not need to be periodically defrosted, as is necessary in the case of known freezer spaces.
  • the refrigeration of the freezer space has been provided so that the air in the freezer space is circulated, with a fan, through a cooling device, such as a cooling radiator, located outside the freezer space. In the cooling radiator, the circulation air cools down
  • the freezer space can be kept at the desired temperature at all times.
  • the channels can be shut off at any time without disturbing or interrupting the operation of the freezer space.
  • the refrigeration units that remain in operation are capable of taking care of the continuous operation of the freezer space without any problems. This means that maintenance will never cause a disruption in the operation of the freezer space. Maintenance is also easy to carry out, as all of the components of the cooling equipment are located in a warm space outside the freezer space.
  • the air supply openings of the cooling air channels leading to the freezer space and the velocity of the air flowing through them have been adapted to cause a laminar air flow in the freezer space. This means that the conditions in the freezer space are as even and similar as possible in every part of the freezer space, which keeps the quality of all of the frozen products at a very high level.
  • the condensate heat released by the condensers is utilized to heat the make-up air of the air conditioning system of other spaces.
  • the freezer space refrigeration method and freezer space according to the invention can be adapted to freezer spaces and deep-freeze warehouses or refrigerated spaces of all kinds and all sizes.
  • the refrigeration equipment is then located entirely outside the freezer space or refrigerated space, because then the entire volume of the freezer space or refrigerated space can be utilized for the frozen goods.
  • the circulation of cooling air and the supply and/or circulation of dried air are made up here by separate circuits but, if needed, they can also be combined for example so that the drying of air is connected to the cooling air circulation circuit.
  • freezer space or refrigerated space prevents moisture and the resulting ice from entering into the freezer space of refrigerated space from outside of it.
  • FIGURES Figure 1 is a schematic vertical sectional view of a deep-freeze warehouse according to the invention.
  • Figure 2 is a schematic horizontal sectional view of the deep-freeze warehouse of
  • Figure 3 is a vertical sectional view of a deep-freeze warehouse.
  • Figure 4 is a horizontal sectional view of the deep-freeze warehouse of Figure 3.
  • Figure 5 is a vertical sectional view of a deep-freeze warehouse.
  • Figure 6 is a horizontal sectional view of the deep-freeze warehouse of Figure 5.
  • Figure 7 is a vertical sectional view of a deep-freeze warehouse.
  • Figure 8 is a horizontal sectional view of the deep-freeze warehouse of Figure 7.
  • Figure 9 shows an air dryer used in the equipment according to the invention.
  • FIGS. 10A-1 OB are schematic views of the refrigeration process according to the
  • Figure 11 shows the Mollier diagram and its comfort zone.
  • Figure 12 shows the Mollier diagram and a known refrigeration drying method.
  • Figure 13 shows the Mollier diagram and the drying refrigeration method according to the invention.
  • Figure 14 is a schematic view of a known space refrigeration solution.
  • Figures 15 and 16 are schematic views of the space refrigeration solution according to the invention.
  • Figures 17-19 are schematic views of refrigeration solutions for a space and refrigeration equipment.
  • Figure 20 is a schematic view of the refrigeration equipment of several freezer spaces.
  • Figure 21 is a schematic view of the refrigeration equipment of freezer spaces and
  • Figure 22 is a view of geothermal equipment connected to the equipment according to the invention.
  • FIG. 1 shows a schematic vertical sectional view of a deep-freeze warehouse 10 according to the invention.
  • the deep-freeze warehouse 10 of Figure 1 is a two-storey building, the first floor of which accommodates a freezer space 20 and, as its ante-room, a refrigerated space 30, which at the same provides access to the freezer space 20.
  • the temperature of the freezer space 20 is, for example, -18 °C and the temperature of the refrigerated space 30 is, for example, +5 °C, in which case the refrigerated space 30 is also equipped with refrigeration equipment. Access to the refrigerated space 30 takes place through the door 31 , from where the freezer space 20 is accessed through the door 21.
  • an excellent advantage in terms of servicing the equipment is the fact that all the equipment needed to refrigerate the freezer space 20 is located outside the freezer space 20.
  • the machine room 40 in which the compressors are located, can have a normal room temperature, for example +20 °C.
  • the temperature of the refrigeration equipment room 50 situated directly above the freezer space 20 can be kept constant, for example equal to the room temperature or it can be allowed to vary according to the outside temperature.
  • the refrigeration equipment room 50 is a space separate from the freezer space 20, it is never as cold in there as in the freezer space 20, which also makes it easy to service the equipment of this space. Because there is no refrigeration equipment in the actual freezer space 20 of the deep- 1 freeze warehouse 10 according to the invention shown in Figure 1.
  • FIG 2 shows a schematic view of the second floor of the deep-freeze warehouse 10 of Figure 1 , which is located above the freezer space 20 and the refrigerated space 30.
  • the machine room 40 and the refrigeration equipment room 50 are located on this floor.
  • Figure 2 shows that in the refrigeration equipment room 50 of the deep-freeze warehouse 10, there are three cooling air channels 51 , each of which has a separate refrigeration unit 52 including a fan and a cooling radiator.
  • Figure 3 shows a deep-freeze warehouse 10, in which the air dryer 41 takes air from both the refrigerated space 30 through the opening 32 and from the freezer space 20 through the opening 56, in which case the air dryer 41 also directly dries the air in the freezer space 20.
  • the quantities and ratios of the air flows coming from the refrigerated space 30 and the freezer space 20 can be adjusted and mixed according to the prevailing conditions, if needed also so that the air to be dried can be taken from only one of the spaces.
  • Figure 6 shows the second floor of the deep-freeze warehouse 10 of Figure 5. It can be seen from the figure that a first air dryer 42 takes air from the hallway 60 through the opening 62 and/or from the refrigerated space 30 through the opening 33 and conducts the dried air to the refrigerated space 30 through the opening 34. A second air dryer 41 takes air from the refrigerated space 30 through the opening 32 and blows the dried air into the freezer space 20 through three dry air channels 43 into three cooling air channels 51. This allows the air dried in the air dryer 41 to be distributed evenly into the circulation air flows of the cooling air channels 51.
  • Figure 7 shows a deep-freeze warehouse 10, in which there is no refrigerated space in connection with the freezer space 20.
  • the freezer space 20 is, however, refrigerated using a refrigeration unit 52 including a fan and a cooling radiator, located outside the freezer space 20, so that the cooling air used to refrigerate the freezer space 20 is circulated, through the opening 54, the cooling air channel 51 , the refrigeration unit 52 and the opening 55, back into the freezer space 20.
  • the refrigeration equipment also includes, as usual, a compressor and a condenser located outside the freezer space 20, but these are not shown in the figure.
  • dried air is conducted into the freezer space 20 through the air dryer 41 so that the dried air is mixed with the cooling air flowing in the cooling air channel 5 .
  • an overpressure is created in the freezer space 20.
  • Figure 8 shows the second floor of the deep-freeze warehouse 10 of Figure 7, i.e. the refrigeration equipment room 50.
  • this space is the only auxiliary space needed, which can contain all of the equipment needed to refrigerate the freezer space 20, with the exception of the condenser located outside.
  • circulation air is used to refrigerate the freezer space 20, there are no refrigeration devices in the freezer space 20.
  • Figure 8 shows three cooling air channels 51 , each of which has a refrigeration unit 52 including a fan and a cooling radiator. The dried air conducted through the refrigeration device 53 and the air dryer 41 is divided into three parts, conducted through the dry air channels 43 and mixed with the circulation air flows of the cooling air channels 51.
  • FIG 9 shows an air dryer 41 used in the equipment according to the invention, which is a so-called drum dryer.
  • this dryer is a so-called sorption- type dryer, which makes it possible to achieve a sufficient level of hygiene. There is not enough moisture building up in the dryer to cause bacterial growth, which would create a contamination risk in the food industry.
  • the air dryer 41 of Figure 9 includes a slowly rotating rotor 71 , through the cells of which the air to be dried 72 is conducted. In the situation shown in Figure 9, the air to be dried 72 is conducted through those cells of the rotor 71 that at that time are located in the bottom portion of the rotor 71.
  • the cells in the rotor 71 bind moisture, after which the dry air 73 is removed from the rotor 71 using the fan 74.
  • the air bound in the rotor 71 is removed using regeneration air 75 so that the air is heated up using the heating radiator 79 and the hot air is conducted to those cells of the rotating rotor 71 that at that time are located in the upper portion of the rotor 71.
  • the moisture in the cells of the rotor 71 is then transferred into the hot air to be conducted through the cells and the moist air 77 is conducted away from the air dryer 41 using the fan 77.
  • the regeneration air 75 is taken from the outside air and the hot and moist air conducted through the rotor 71 is also conducted into the outside air, in which case the regeneration air circuit of the air dryer 41 is separate from the circuit of the air to be dried 72 and from that of the dried air 73.
  • Figure 10A shows the main principle of the dry refrigeration according to the invention. According to it, the cooling air to be conducted into the object to be refrigerated is dried using the dryer 41 prior to refrigerating the cooling air using the cooling radiator 52, after which the dry cooling air is conducted to the object to be refrigerated. This single-stage cooling air drying and refrigeration is usually sufficient for refrigerating room spaces, such as for example store spaces.
  • Figure 10B shows schematically the dry refrigeration principle according to the invention for refrigerating a colder space, such as a freezer space. According to it, the cooling air to be conducted to the object to be refrigerated is dried and refrigerated in two or more stages.
  • Figure 10B shows a schematic view of an example of a two-stage process.
  • Figure 11 shows a known Mollier diagram, wherein the horizontal axis has a scale for the amount of water contained in air, i.e. water kg/kg of air, and the vertical axis shows the air temperature °C.
  • the curves pointing from the bottom left to the top right illustrate the relative humidity of the air as a percentage.
  • the black area inside the diagram illustrates the comfort zone within which the air humidity and temperature conditions should preferably be in order to feel comfortable.
  • the area has the shape of a triangle and the points at its ends have been marked with the reference numbers , 2 and 3. It has been observed that most people find ambient air conditions to be comfortable when the relative humidity of the air is 30%-70%.
  • the comfortable temperature ranges from 20°C to 25°C, with the relative humidity of the air being 30-40%.
  • Point 1 of the triangle corresponds to a relative humidity of 30% and a temperature of 25°C.
  • Point 2 of the triangle corresponds to a relative humidity of 42% and a temperature of 20°C.
  • the triangle's third point, i.e. point 3 corresponds to a relative humidity of 70% and a temperature of 22°C.
  • Figure 12 first shows, with the help of a Mollier diagram, a known refrigeration drying method which is used, among other things, for refrigerating grocery stores.
  • the outside temperature is 25°C
  • the relative humidity 60% contains 12 g of water/kg of air.
  • This point has been illustrated with the reference number 1 in the diagram of Figure 12.
  • the dew point i.e. the relative humidity is 100%. This situation is illustrated by the reference number 2.
  • the air is refrigerated further, a lot of water is removed from it by condensing.
  • the relative humidity of the air to be taken from outside is 60%.
  • the starting point has been marked with the reference number 1.
  • this spot has been marked with the reference number 2.
  • the spot of the reference number 3 can be reached, in which the relative humidity of the air is slightly under 30% and the temperature 28°C.
  • the air is cooled down to the spot marked with the reference number 4 to the temperature 20°C, in which the relative humidity is 42%. It corresponds to the point 3 of the comfort zone of Figure 11 and the corresponding point 4 of Figure 12.
  • Figure 13 shows an essential characteristic of the process according to the invention, according to which the air to be refrigerated at no stage is close to the dew point, as it is in known processes. This means that all of the equipment is dry all the time and thus also hygienic.
  • outside air is brought to the cooling radiator 87 through the inlet air valve 81 , which outside air is moist for the most part of the year.
  • the air In summer, when the outside temperature is +25°C and the relative humidity 60%, the air may contain more than 12 g of water/kg of air. If the inlet air is cooled down to a temperature of, for example, +8°C, a very high amount of water is condensed in the cooling radiator 87. This means that the entire cooling radiator 87 is wet throughout all the time and its moisture also easily spreads to the air channels. Moisture increases, near the cooling radiator 87, detrimental mold and bacterial growth which can propagate, in addition to the air channels, also to the space 100 to be refrigerated.
  • the equipment arrangement of Figure 15 partly has the same components, but the operation of the entire equipment is completely different due to the drying refrigeration method.
  • Outside air is brought into the space 100 to be refrigerated, with an inlet air fan 89, through the inlet air valve 81 , the filter 83 and the heat recovery device 84, but what is essential is that the process is controlled in terms of moisture measurement. No moisture is brought in. If there is too much moisture in the outside air, it is removed with the air dryer 41 prior to refrigeration. The refrigeration of the dry air that takes place in this case does not lead anywhere near the dew point, and the entire equipment remains dry throughout the process, with no danger of mold and moisture problems.
  • a mixing valve 85 which can be used to adjust the amount of circulation air to be conducted through the space 100 to be refrigerated.
  • the ratio of the circulation air to the amount of air coming through the inlet air valve 81 can be between between 0% and 100%, depending on whether make-up air is needed in the space 100 to be refrigerated and whether air is removed from there into another space. If the space 00 is, for example, a storage space, and if no air is removed through the exhaust fan 92, make-up air from the outside air is not necessarily needed at all.
  • a mixing valve 85 which can be used to adjust the amount of circulation air to be conducted through the space 100 to be refrigerated between 0% and 100%.
  • the amount of the air flow through the air dryer 41 can be adjusted between 0% and 100%. All options and combinations of both adjustments, such as the circulation air adjustment and the adjustment of the air flow through the air dryer 41 , are possible.
  • the space 100 to be refrigerated can be practically any space, such as a cold storage warehouse, a space for freezing products, a storage space for frozen products, an in-store deep-freeze box or cabinet or, for example, also a store room space.
  • the air flow can even be arranged, for example, so that no make-up air is taken from the outside air and that all of the air going into the space 100 to be refrigerated goes through the air dryer 41.
  • a situation like this could arise, for example, at night in summer, when the space in question is a cold storage warehouse or a store where no people are present. In this case, no make-up air is needed to remove the carbon dioxide produced by humans. In a case such as this it does not make sense either to bring water, together with the outside air, into the refrigeration system and into the space to be refrigerated, because in summer the outside air contains a lot of water.
  • Figure 16 shows a solution according to the invention for arranging the refrigeration and air-conditioning for the space 100.
  • a heat recovery device is not necessary if the system includes refrigeration devices whose condense heat recovery device 86 replaces the heat recovery device.
  • the condense heat recovery device 86 of the refrigeration devices located in the inlet air channel of the grocery store is enough to heat the entire store space 100.
  • the flow of the air coming into the space 00 to be refrigerated is adjusted with the inlet air valve 81 and the removal of air is adjusted with the exhaust fan 92.
  • the amount of circulation air is adjusted with the mixing valves 85 and 69.
  • the drying of air and the mixing of dry air with the inlet or circulation air is adjusted with the mixing valve 69 and with the control valve 70 of the air channel leading to the air dryer 41.
  • All valves of the air-conditioning and refrigeration equipment such as the inlet air valve 81 and the circulation air mixing valve 85 as well as the mixing valve 69 and the control valve 70 located in connection with the air dryer can be adjusted to any position and also be completely open or closed.
  • the air- conditioning, refrigeration and heating of the space 100 can be adjusted so that all of the possible adjustment options are available.
  • the desired overpressure can be created in the space 100, whereby air brought from outside air or mixed using the air circulation is blown into the space 100 to be refrigerated, which air is dried with the air dryer 41 in the desired ratio.
  • the equipment can, in winter conditions, be adjusted so that the air inlet valve 81 and the mixing valve 69 are open. Cold and dry outside air is thus conducted into the space 100, which air can be heated as needed with the help of the condense heat recovery device 86 of the refrigeration devices and/or the heat radiator 88.
  • the air of the space 100 can, at the same time, also be circulated in the desired ratio by adjusting the mixing valve 85.
  • the control valve 70 of the air channel leading to the air dryer 41 can be closed, because in winter, the cold outside air contains so little moisture that the moisture does not condense into water in the equipment or in the air channels.
  • Figure 17 shows the equipment according to the invention, related to the space 100 to be refrigerated, such as a grocery store and its refrigeration equipment 101 , such as refrigeration cabinets or refrigeration shelves for food products or frozen products.
  • the circuit shown at the bottom of Figure 17, related to the refrigeration of the space 100 and the drying of air essentially corresponds to the solutions shown in the previous figures.
  • the air-conditioning and refrigeration equipment of space 100 includes, as in the previous Figure 16, a condense heat recovery device 86, a heat radiator 88, a cooling radiator 87 and fans 89, 91 and 92. All of the air channel mixing valves are not shown in Figure 17. However, the air flows of all of the channels of the equipment can be adjusted steplessly from the closed position to the completely open position.
  • the inlet air inlet flow it is possible to adjust, among other things, the inlet air inlet flow, the proportion of outside air in the circulation air, the amount of exhaust air, the ratio of the atmospheric pressure of the space 100 to the outside air pressure, and the amount of air flow conducted through the air dryer 41.
  • Figure 17 shows a solution to the above-described problem.
  • air that has been dried with the air dryer 41 is conducted to the refrigeration equipment 101.
  • the air in the vicinity of the glass doors of the refrigeration equipment 101 is sufficiently dry, it contains no moisture that could condense on the surface of the glass doors.
  • both the channel for the air 72 to be dried going to the rotor 71 and the channel for the air 73 leaving the rotor 71 are branched into two channels.
  • the same air dryer 41 can then be used to dry both the air to be conducted into the store space 100 and its refrigeration equipment 101.
  • Figure 18 shows a diagram of the equipment according to the invention, which includes the grocery store space 100, the refrigeration equipment 101 and the air dryer 41.
  • the diagram of Figure 8 shows two pieces of refrigeration equipment 101 , but the equipment can just as well comprise several pieces of refrigeration equipment or groups of refrigeration equipment, to which dry air is conducted from the air dryer 41. This way, dry air can be conducted from the same air dryer 41 into both the grocery store space 100 and its refrigeration equipment 101.
  • Figure 19 also shows a diagram of the equipment according to the invention, which includes the grocery store space 100 and its refrigeration equipment 101.
  • the equipment of Figure 19 there are two air dryers 41a and 41b.
  • the first air dryer 41a then dries the air to be conducted into the grocery store space 100 and the second air dryer 41b dries the air to be conducted into the grocery store's refrigeration equipment 101.
  • the operation of the air dryers 41a and 41b has been connected in series so that part of the air going to the grocery store space 100 that has already been dried is conducted to the second air dryer 41b. Even drier air is then obtained from the second air dryer 41b, which is conducted to the grocery store's refrigeration equipment 101 , of which there can be several.
  • the air to be conducted into freezer spaces contains at maximum 0.5 g of water/kg of air. This means that the dew point of the air is then below -18°C, which means that no frost or ice is built up on the surface of the frozen products. Nor does any frost build up on the glass doors of the refrigeration equipment 101 , and no moisture condenses on other parts of the refrigeration equipment
  • Figure 20 shows equipment in which dry air is fed from one air dryer 41 to several freezer spaces 20.
  • the equipment of Figure 20 belongs, for example, to a large industrial plant which is, for example, a bakery, a food factory, a frozen products warehouse or similar with several freezer spaces 20.
  • a large industrial plant which is, for example, a bakery, a food factory, a frozen products warehouse or similar with several freezer spaces 20.
  • the intense frost and ice build-up in the freezer spaces is a major problem that causes a lot of production stoppages and maintenance shutdowns, during which the ice built up in the spaces and the refrigeration equipment is melted.
  • dry air is fed in the facility into two or more freezer spaces 20 from one air dryer 41 or, alternatively, from an air dryer unit comprised of several dryers.
  • the feeding of dry air into the freezer spaces prevents frost and ice building up in the spaces and the production stoppages caused by these.
  • What is essential in the equipment of Figure 20 is that the feeding of dry air into the freezer spaces 20 is carried out in a centralised manner. A separate air dryer is thus not needed in each freezer space.
  • the advantage of centralised air dryer equipment is major space savings and more simple adjustment and maintenance of the equipment.
  • the air dryer 41 or air dryer unit comprised of several dryers can be located in the same building as the freezer spaces 20, but it can advantageously also be located outside the freezer space building or buildings in a separate building.
  • the free placing of the pieces of equipment in relation to one another results from the fact that dry air is easy to transfer even long distances along a pipe.
  • the pipes do not necessarily even have to be insulated, because dry air does not contain water which could freeze in winter.
  • Figure 21 shows the equipment according to the invention in which dry air is fed from one air dryer 41 into several freezer spaces 20 and into at least one refrigerated space 30.
  • Bakeries or food factories for example, have this kind of equipment.
  • Frost and ice build-up in refrigerated spaces and freezer spaces is a problem in all kinds of refrigerated spaces, causing a lot of production stoppages and maintenance shutdowns, during which the ice built up in the spaces and the refrigeration equipment is melted.
  • the frost and ice build-up is prevented by conducting dry air into all of the refrigerated spaces and freezer spaces. It can be done in a centralised manner from one or several air dryers 41 by dividing the air flow into several parts.
  • the air dryer 41 can even be located far away from the refrigerated spaces and freezer spaces, because dry air pipes can be made quite long without problems.
  • Figure 22 shows equipment which has two spaces 100. Air, which can be dried with the air dryer 41 before feeding into the spaces 100, is conducted to both.
  • geothermal equipment 103 is used for heating and refrigerating the air.
  • the use of geothermal energy is advantageous, because the temperature, such as for example 15°C- 16°C, of the refrigeration solution refrigerated by the geothermal equipment 103 is enough for the dry refrigeration according to the invention, to refrigerate the air, for example, from the temperature 30°C to the temperature 20°C.
  • the temperature of the refrigeration solution must be made considerably lower.
  • the air to be fed to the circulation air that refrigerates the freezer space or refrigerated space can be made so dry that, when the circulation air is refrigerated, the possible small residual moisture left in the air does not condense nor freeze in the circulation air channel or in the freezer space or the refrigerated space.
  • the air which is at a temperature of, for example, -18 °C, to be fed to the freezer space, may contain at maximum about 0.3 g of water/kg of air.
  • the air dryer is most advantageously a so-called drum dryer and not a so-called condenser dryer where moisture is condensed into water. If there is a lot of moisture in connection with the dryer, it easily creates bacterial growth in the dryer, which, especially in the food industry, causes a contamination risk.
  • the dryer must dry the air so dry that, at the temperature of -18 °C, no ice is built up, i.e. the temperature of the drying process must be above the dew point.
  • a dryer is, for example a so-called sorption-type dryer, which makes it possible to achieve a sufficient level of hygiene.
  • dry air is mixed to be part of the circulation air of the refrigeration of the freezer space or refrigerated space.
  • This solution is advantageous because only a small amount of air to be dried is needed compared to the amount of refrigeration circulation air.
  • the volume flow of the dry air is only about 1/20 of the volume flow of the circulation air.
  • the object of the invention is equipment which has two or more different spaces, such as a freezing space and freezer storage or other refrigerated space.
  • the operation of all of the equipment can then be handled in a centralised manner so that dry air is fed from one common dry air device to all of the different spaces, such as the freezing unit, the cold storage etc.
  • no separate air dryer is needed for the freezing space and no separate air dryer is needed for the deep-freeze storage or cold space.
  • pre-refrigeration can be arranged with a second dryer and refrigeration device or so that pre-refrigeration is provided by the refrigeration system of the freezer storage).
  • the object of the invention is also the refrigeration of freezer spaces or refrigerated spaces of stores, such as especially grocery stores.
  • supermarket stores are air- heated.
  • the needed refrigeration equipment such as freezer cabinets and freezer boxes or refrigerated spaces and their refrigeration devices are located in the store space in the food section.
  • Such conditions are very disadvantageous for refrigeration equipment, because the operating time and capacity of the refrigeration machines are partly also dependent on the moisture and temperature of the air present in the
  • the decrease in moisture substantially reduces the risk of mold sporulation in the air- conditioning equipment, which improves the hygiene of the inlet air and increases comfort for people.
  • the decrease in moisture in the grocery store air space also prevents the sweating of the doors of the refrigerated cabinets, i.e. the condensing of moisture on the surface of the doors' glass.
  • the cooling air to be fed into the refrigeration equipment, into the freezing space, into the deep-freeze warehouse and the ambient air is always dried before refrigeration to the extent that the residual moisture present in the air does not condense into water in the cooling radiator through which the cooling air goes into the object to be refrigerated. This is the only way to prevent moisture from entering into the cooling channels, the object to be refrigerated and the products kept in the objects, in which the condensing moisture would cause frost, ice build-up and possibly also hazardous mold and bacterial growth.
  • Air that contains a maximum of 2 g of water/kg of air is conducted into refrigerated spaces, the temperature of which is approximately 5°C. Air that contains a maximum of 0.3 g of water/kg of air is conducted into frozen product warehouses and freezing rooms, the temperature of which is below - 18°C.
  • Dry refrigeration air can be conducted into the object as is, but it can also be mixed with the circulation air according to need.
  • low ventilation is sufficient compared with previously known refrigeration methods, in which boosting refrigeration often just increases the moisture brought into the object. Bringing moisture into the object has harmful consequences, as has been stated above.
  • the refrigeration process is controlled according to the absolute humidity values and, if needed, also with the help of a carbon dioxide sensor. It is also possible to control the absolute humidity values and, if needed, also with the help of a carbon dioxide sensor. It is also

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Cold Air Circulating Systems And Constructional Details In Refrigerators (AREA)

Abstract

L'invention porte sur un procédé de réfrigération pour réfrigérer un espace, tel qu'un espace de congélateur (20), un espace de congélation, un espace réfrigéré, un espace de stockage (100) ou un autre espace froid, selon lequel procédé l'espace est réfrigéré par le fait d'acheminer de l'air de refroidissement réfrigéré dans l'espace, et l'air de refroidissement est réfrigéré de telle sorte que l'air de refroidissement est tout d'abord séché jusqu'à une teneur en humidité telle que la température de l'air de refroidissement reste supérieure au point de rosée quand l'air de refroidissement est ensuite réfrigéré. L'équipement de réfrigération comprend au moins un séchoir d'air pour sécher l'air de refroidissement et au moins un élément de refroidissement pour réfrigérer l'air de refroidissement qui a tout d'abord été séché avec le séchoir d'air.
PCT/FI2013/000044 2012-11-19 2013-11-19 Procédé de réfrigération et équipement de réfrigération WO2014076362A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP13854493.7A EP2920530A4 (fr) 2012-11-19 2013-11-19 Procédé de réfrigération et équipement de réfrigération

Applications Claiming Priority (6)

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FI20120384A FI124690B (fi) 2012-11-19 2012-11-19 Pakastetilan jäähdytysmenetelmä ja -laitteisto sekä pakastetilajärjestely
FI20120384 2012-11-19
FI20130122 2013-04-22
FI20130122 2013-04-22
FI20130167 2013-06-10
FI20130167 2013-06-10

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5066563B2 (ja) * 2009-12-02 2012-11-07 株式会社向井珍味堂 冷凍庫

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Publication number Priority date Publication date Assignee Title
SE7909844L (sv) * 1979-11-29 1981-05-30 Electrolux Ab Sett och anordning for att halla ett frysskap frostfritt
US6155060A (en) * 1999-11-05 2000-12-05 Munters Corporation Condensation and frost control system
US20100212343A1 (en) * 2006-06-20 2010-08-26 Hill Phoenix, Inc. Refrigerated case with low frost operation

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
JP5066563B2 (ja) * 2009-12-02 2012-11-07 株式会社向井珍味堂 冷凍庫

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Title
See also references of EP2920530A4 *

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EP2920530A1 (fr) 2015-09-23

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