EP1020149A2 - Verfahren und Vorrichtung zum Steuern der Kältebedingungen in Kühleinheiten - Google Patents

Verfahren und Vorrichtung zum Steuern der Kältebedingungen in Kühleinheiten Download PDF

Info

Publication number
EP1020149A2
EP1020149A2 EP00100725A EP00100725A EP1020149A2 EP 1020149 A2 EP1020149 A2 EP 1020149A2 EP 00100725 A EP00100725 A EP 00100725A EP 00100725 A EP00100725 A EP 00100725A EP 1020149 A2 EP1020149 A2 EP 1020149A2
Authority
EP
European Patent Office
Prior art keywords
temperature
control unit
value
refrigerated
measure
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP00100725A
Other languages
English (en)
French (fr)
Other versions
EP1020149A3 (de
Inventor
Romolo Rossi
Francesco Pellovini
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ISA SpA
Original Assignee
ISA SpA
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 IT1999UD000005 external-priority patent/IT1310521B1/it
Priority claimed from IT1999UD000007 external-priority patent/IT1310523B1/it
Priority claimed from IT1999UD000006 external-priority patent/IT1310522B1/it
Application filed by ISA SpA filed Critical ISA SpA
Publication of EP1020149A2 publication Critical patent/EP1020149A2/de
Publication of EP1020149A3 publication Critical patent/EP1020149A3/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47F—SPECIAL FURNITURE, FITTINGS, OR ACCESSORIES FOR SHOPS, STOREHOUSES, BARS, RESTAURANTS OR THE LIKE; PAYING COUNTERS
    • A47F3/00—Show cases or show cabinets
    • A47F3/04—Show cases or show cabinets air-conditioned, refrigerated
    • A47F3/0404—Cases or cabinets of the closed type
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47F—SPECIAL FURNITURE, FITTINGS, OR ACCESSORIES FOR SHOPS, STOREHOUSES, BARS, RESTAURANTS OR THE LIKE; PAYING COUNTERS
    • A47F3/00—Show cases or show cabinets
    • A47F3/04—Show cases or show cabinets air-conditioned, refrigerated
    • A47F3/0482—Details common to both closed and open types
    • 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
    • F25D21/002—Defroster control
    • 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
    • F25D29/00—Arrangement or mounting of control or safety devices
    • 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
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/02—Humidity
    • 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
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/11—Sensor to detect if defrost is necessary
    • 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
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/11—Sensor to detect if defrost is necessary
    • F25B2700/111—Sensor to detect if defrost is necessary using an emitter and receiver, e.g. sensing by emitting light or other radiation and receiving reflection by a sensor
    • 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
    • F25D2400/00—General features of, or devices for refrigerators, cold rooms, ice-boxes, or for cooling or freezing apparatus not covered by any other subclass
    • F25D2400/36—Visual displays
    • 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
    • F25D2700/00—Means for sensing or measuring; Sensors therefor
    • F25D2700/14—Sensors measuring the temperature outside the refrigerator or freezer
    • 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
    • F25D2700/00—Means for sensing or measuring; Sensors therefor
    • F25D2700/16—Sensors measuring the temperature of products

Definitions

  • This invention concerns a method to control the refrigeration conditions of refrigerated modules, and the device which achieves said method.
  • the invention is suitable to be used in showcases and refrigerated modules used to display, preserve and sell refrigerated food products, in order to reduce the overall consumption of electric energy and to optimize the preservation conditions of the food products.
  • the invention allows to reduce to a minimum the influence of the defrosting and anti-misting cycles on the preservation of the food products; it also ensures that the optimum thermostat parameters are maintained for the correct preservation of the refrigerated food stuffs.
  • frost, ice or snow on the surfaces of an evaporator during the functioning of a refrigeration plant can assume proportions such as to compromise the correct functioning of the refrigeration system; therefore it is usual practice to follow programmed defrosting cycles to melt the deposits of frost or ice from the surfaces of the evaporator.
  • programmed defrosting cycles are performed automatically, at fixed periods of time, determined according to experience and the functioning parameters of the refrigeration plant.
  • every defrosting cycle causes an increase in temperature and therefore has a negative influence on the preservation of the products themselves, and in any case causes a high energy consumption, at the end of the cycle, in order to restore the correct refrigeration conditions.
  • the state of the art includes a method which provides to make a series of short defrosting cycles, at a limited interval from each other, and then to make a complete defrosting only after the refrigeration plant has been functioning for a long period of time.
  • This solution does not solve the problem completely, since the defrosting operations do not take into account the real situations which have occurred inside the refrigerated module.
  • Another problem connected with maintaining optimum refrigeration conditions is that when the humid air contained inside the refrigerated compartment comes into contact with a surface which has a lower temperature than dew temperature, condensation forms on said surface and, if the surface is transparent, causes it to mist over.
  • the state of the art provides to use electric anti-misting devices, including the heating filaments of the type used in the heated rear windows of motor vehicles.
  • electric fans are also used, suitable to direct a flow of air, heated or not, onto the surfaces most subject to the phenomenon of misting.
  • the high consumption of electric energy is due not only to the power absorbed directly by the anti-misting devices, but also to the fact that the refrigeration system of the refrigeration plant must be activated more frequently and for longer periods of time to deal with the increase in temperature inside the showcase caused by the anti-misting devices.
  • the anti-misting devices which function constantly unless there are correction interventions made, can cause a deterioration of the preservation conditions of the food products.
  • thermohygrometric parameters are controlled using thermoregulators, or other similar control devices, installed inside the volume of the refrigerated module in a position such that the detector element is suitable to be lapped by the cooling air.
  • thermoregulators are programmed to define a thermostat setting suitable to ensure the correct conditions for preserving the food products.
  • the temperature of the cooling air is constantly measured and, if variations are monitored in the real temperature with respect to the programmed value, an intervention is made on the refrigeration plant to restore correct conditions.
  • This method of control ensures that only the thermostat parameters of the cooling air are maintained; it does not allow to control the actual, real temperature of the products contained in the refrigerated module. This is a problem since the action of external agents can alter the relation between the thermostat value (air temperature) and the real temperature of the product.
  • a first purpose of the invention is to determine, in a manner which uses a processor, the activation and duration of the defrosting cycles in an evaporator in a refrigeration plant, in such a way as to reduce the influence of the defrosting operations on the parameters of preservation of the refrigerated products.
  • the invention provides to start the defrosting cycles only when necessary, that is, when the conditions inside the refrigeration plant require it because the frost or ice on the outside surfaces of the evaporator begins to influence the thermo-dynamic parameters of the system to a considerable extent.
  • the invention provides to terminate the defrosting cycle at the actual moment when correct functioning conditions have been restored.
  • Another purpose of the invention is to control, in a manner using a processor, the activation and de-activation of the electric anti-misting devices so as to reduce the consumption of electric energy.
  • a further purpose of the invention is to regulate the thermostat parameters so as to ensure that the foodstuffs contained therein are perfectly preserved and maintained irrespective of the quantity and type of light striking them.
  • the invention provides to regulate the thermostat parameters according to the intensity of the light which strikes the products on display.
  • the invention provides to control and measure the values of a plurality of parameters of the refrigeration plant, and to begin defrosting of the evaporator only when a significant variation is registered in one or more of said parameters with respect to normal working conditions.
  • the significant variation is interpreted by the control system as a symptom of a behavior of the evaporator which is no longer efficient, caused by the presence of an excessive quantity of frost or ice on the walls of the evaporator.
  • the defrosting cycle is taken to be terminated, and is therefore stopped, when the controlled parameters return within the values corresponding to an efficient functioning of the evaporator.
  • the parameters measured include at least the air temperature at inlet to and outlet from the evaporator.
  • the pressure of the gas circulating in the cooling circuit is also measured.
  • the speed of circulation of the air inside the refrigerated space is also measured.
  • the invention also uses means to physically detect the growth of deposits of frost on the surfaces of the evaporator and uses these values as a threshold value; when this value is exceeded, the defrosting cycle is activated.
  • the invention also uses the parameter relating to the time which has passed since the last defrosting operation was carried out.
  • the invention also uses the parameter relating to the time during which the refrigerated showcase has remained open, indirectly deducing the quantity of humidity introduced from outside into the refrigerated compartment containing the products.
  • control system includes means suitable to achieve self-learning operations, in order to use the data acquired in the first defrosting cycles to establish the times and modes to be used in subsequent defrosting cycles.
  • the invention to establish the end of the defrosting cycle, provides to monitor the actual temperature assumed by the surface of the evaporator. When this temperature reaches a pre-set value, the control system interprets this situation as a signal that all the frost on the surfaces of the evaporator has been completely melted and commands the defrosting cycle to stop.
  • optical means are provided suitable to monitor that the frost is completely melted and to give permission for the defrosting cycle to be interrupted.
  • the defrosting cycle is ended a fixed time after starting.
  • the invention provides to continuously measure at least the temperature t s of the transparent surface of the module on which it is desired to prevent the formation of condensation, and on which the electric anti-misting devices are installed; moreover, it provides to measure the outside temperature t a and the relative humidity ⁇ a of the location where the refrigerated module is installed.
  • the invention provides to measure the humidity ⁇ s inside the refrigerated module.
  • the electric anti-misting devices are normally kept inactive, and are only activated when the values detected of the temperatures t s and t a and of the relative humidity ⁇ a assume, within a defined field of tolerance, pre-set reference values.
  • the reference values pre-determined theoretically or experimentally and memorized in tables in an electronic control unit which manages the functioning of the refrigerated showcase, are those which, under normal working conditions of the refrigeration plant, cause the afore-said surface to mist over.
  • the reference values mainly take into account that a high relative humidity ⁇ a of the premises where the refrigerated showcase or module is installed will systematically cause condensation on a surface every time the temperature t s of the surface is less than the temperature t a of the premises and the dew temperature t r of the air inside said premises.
  • the invention provides to monitor the development in time of these reference values in order to activate the electrical anti-misting devices before the phenomenon of misting-over occurs.
  • the time that the anti-misting devices are activated may have a fixed and pre-determined value.
  • the anti-misting devices are automatically de-activated when the electronic control unit detects that the value of the temperature t s has risen above a pre-determined threshold, according to the pre-defined conditions of temperature and outside humidity. If these external, environmental conditions change, the threshold value corresponding to the de-activation of the anti-misting devices is also modified in a correlated manner.
  • the invention provides to use detection means, or light detectors, located inside the refrigerated module and suitable to detect the quantity of light or infra-red entering the cooling volume.
  • These detection means are advantageously located very near the products on display, so as to be able to detect, in a credible manner, the actual variation in the temperature of the products caused by the infra-red rays, by means of calculus algorithms.
  • the invention provides to condition the functioning of the refrigeration plant according to the quantity of infra-red measured by the detection means, so that the temperature of the products displayed is the optimum temperature for a perfect preservation.
  • the invention provides to give an alarm signal to the assistants every time the quantity of infra-red measured by the detection means reaches too high a threshold value which cannot be corrected by a modification to the thermostat setting.
  • Another variant provides that, every time the quantity of infra-red measured by the detection means reaches defined threshold values, means are activated to protect the products displayed, such as for example photochromic glass, screens or otherwise, chosen according to the use and location of the refrigerated module.
  • Fig. 1 shows a refrigerated showcase 10, of the type used to display and sell ice cream, comprising at the front part a glass pane 11 and at the rear a hinged top 12 which can be opened and through which the sales assistant can access the refrigerated compartment located inside the showcase.
  • the showcase 10 is equipped with a cooling circuit 17 shown schematically in its essential components in Fig. 2; it comprises an evaporator unit 13, a compressor unit 14, a condenser unit 15 and a stabilizing member 16 to stabilize the cooling fluid, such as an expansion valve, a capillary or other similar element.
  • a cooling circuit 17 shown schematically in its essential components in Fig. 2; it comprises an evaporator unit 13, a compressor unit 14, a condenser unit 15 and a stabilizing member 16 to stabilize the cooling fluid, such as an expansion valve, a capillary or other similar element.
  • the functioning of the cooling circuit 17 is controlled and managed by an electronic unit, or CPU, 18 which is programmed to maintain inside the showcase 10 the desired hygrothermal conditions according to the organoleptic characteristics of the food product to be refrigerated.
  • CPU electronic unit
  • frost 26 is deposited on the outer surfaces of the fins 19 and the tubes 20 of the evaporator 13, which is transformed into ice if it is not completely eliminated.
  • the layer of frost 26 increases in thickness, and constitutes an obstacle to the flow of air, indicated by the arrows 21 in Fig. 2, through the evaporator 13 and thus lowers the efficiency of the evaporator 13 and the refrigeration plant.
  • a defrosting cycle which can be done, for example, by making a hot fluid circulate inside the tubes 20 of the evaporator, or by making a solution with a low freezing point fall into the evaporator, or by switching off the compressor 14 and waiting for the frost 26 to melt naturally.
  • the procedure used for defrosting is in any case irrelevant for the purposes of the invention.
  • the invention provides to identify, according to the actual working conditions of the refrigeration plant and to the conditions of the refrigerated environment, the most appropriate moment to begin every defrosting cycle, and the most appropriate moment to end it.
  • the circuit suitable to make the control mentioned above comprises temperature monitoring means 22a and 22b located respectively at inlet and outlet of the evaporator 13 and suitable to determine the temperature of the air respectively entering and emerging from the evaporator 13.
  • the circuit also comprises means 23 suitable to detect the pressure of the cooling fluid, arranged along the cooling circuit 17.
  • optical detection means 25 suitable to measure the thickness of the layer of frost 26 which has formed on the fins 19 and tubes 20 of the evaporator 13, consisting of a light emitter 27 and a mating receiver 28.
  • the light emitter 27 advantageously consists of a fiber optic suitable to emit a luminous signal
  • the receiver 28 consists of an optical detector which is suitable, according to the luminous signal reflected by the layer of frost 26, to calculate the thickness thereof.
  • the control unit 18 comprises a timer 29 suitable to measure and memorize the time which has elapsed since the last defrosting cycle, and to measure the duration of every defrosting cycle.
  • the respective parameters measured by the means 22a, 22b, 23, 24 and 25 are sent to the control unit 18, which is suitable to process them according to a pre-established program, possibly interpolating them with each other, and to establish when, inside the showcase 10, the actual conditions have been created which require a defrosting cycle to be started.
  • a first embodiment provides to start the defrosting cycle when the difference between the temperature of the air entering the evaporator 13, measured by the probe 22a, and the temperature of the air leaving the evaporator 13, measured by the probe 22b, goes below a pre-determined threshold, when there are defined and pre-determined conditions of the cooling fluid pressure and possibly of the air speed inside the showcase 10.
  • control unit 18 according to the signals relating to the measurements made by the sensor 23, and possibly by the sensor 24, which define the working conditions of the refrigeration plant, determines an intervention threshold relative to the difference between the outlet temperature and the inlet temperature of the air to/from the evaporator 13.
  • control unit 18 supplies a signal to activate the defrosting cycle.
  • the defrosting cycle can be actuated by acting on a switch 31.
  • this can cause the cooling fluid to be heated and circulate inside the tubes 20 of the evaporator 13 to melt the frost 26.
  • the signal relating to this value of thickness, as detected by the optical sensor 25, is sent to the control unit 18, inside which a threshold value is memorized; when the threshold value is exceeded, the permission for the defrosting cycle to begin is given.
  • one variant of the invention provides to consider the time which has passed since the last defrosting operation was carried out, calculated by the timer 29.
  • control unit 18 sends an alarm message, so that the assistants are warned of a possible malfunctioning of the refrigeration plant.
  • the method provides to define a maximum time threshold; when this is reached, a defrosting cycle is started anyway, even if the actual parameters monitored do not indicate that it is necessary.
  • the timer 29 is also used to measure the time during which the glass 11 or the hinged top 12 stay open, that is, the time during which the refrigerated inner environment of the showcase 10 stays in contact with the outside environment, with the relative exchange of air, and therefore humidity is introduced inside the system.
  • the mean humidity of the inner environment of the showcase 10 may rise, and therefore this can accelerate the formation of frost 26 on the evaporator 13.
  • the control unit 18 can be programmed so as to carry out cross-over comparisons between the parameters detected, and to start the defrosting cycle only when all said parameters, according to the pre-defined thresholds, indicate that defrosting is necessary.
  • a preferential threshold is chosen from among those mentioned above, and the other parameters are used only to confirm the indications supplied by the basic parameter.
  • control unit 18 can make a self-learning program according to which tables are defined of pre-determined values of all the parameters measured, and permission to start defrosting is given without making interpolations or comparisons but simply when the parameters reach said pre-determined values.
  • the first defrosting cycle is always carried out after a pre-set time, in order to define a parameter setting table.
  • a first embodiment of the invention provides to measure, by means of a probe 30, the actual temperature reached by the surface of the evaporator 13.
  • This value is measured continuously and compared by the control unit 18 with a pre-defined threshold value, according to which the frost 26 is assumed to have completely melted.
  • control unit 18 uses the data monitored by the optical detection means 25.
  • the control unit 18 gives permission for the defrosting cycle to be interrupted.
  • the defrosting cycle is interrupted a fixed time after starting, as measured by the timer 29.
  • the temperature values of the surface of the evaporator 13, the actual thickness of the frost 26 and the defrosting time can be appropriately interpolated and compared with each other by the control unit 18 to establish the most appropriate moment to stop defrosting.
  • the glass 11 is equipped with electrically conductive heating filaments 32 suitable to heat the glass 11 when fed with a specific feed tension v alim (Fig. 6).
  • heating filaments 32 instead of the heating filaments 32, it is possible to use glass of a pyrolithic type, or glass suitable to cooperate with fans blowing hot air, or other conventional anti-misting systems.
  • the invention provides to activate the feed to the heating filaments 32 only when the temperature t s of the glass 11, the temperature t a and the relative humidity ⁇ a of the premises where the showcase 10 is installed assume defined reference values.
  • Fig. 6 shows a block diagram of a circuit associated with the control unit 18, suitable to control the anti-misting cycles according to the invention.
  • the temperature sensor 34 detects the temperature t a of the premises where the showcase 10 is installed, the humidity sensor 36 measures the value of relative humidity ⁇ a of the same premises and the temperature sensor 35 detects the temperature t s of the surface of the glass 11.
  • the values detected by the sensors 34, 35 and 36 are sent continuously to the control unit 18, which processes them, possibly interpolating them with each other, and compares them with reference values contained in the memorization unit 33. According to this comparison, the control unit 18 defines when conditions to cause the glass 11 to mist over occur and therefore, as a consequence, provides to close the switch 37, for example a relay switch, to feed the heating filament 32 with the feed tension V alim .
  • control unit 18 monitors the variations in time of said temperature values t a and t s and of the relative humidity ⁇ a and then can be programmed so as to activate the heating filaments 32 before the conditions occur which cause misting over.
  • the time for which the heating filaments 32 are activated may assume a fixed and pre-ordained value corresponding to a programmed anti-misting time.
  • the cessation of feed to the heating filaments 32 is governed by a parameter control made by the unit 18, and in particular by the control of the temperature t s of the glass 11, established according to the external conditions of outside humidity and temperature.
  • a further control of the refrigeration conditions in the showcase 10 is based on the quantity of light "L" which penetrates inside the refrigerated showcase through the glass 11.
  • the light "L" which may be natural, artificial or mixed, can cause the surface temperature of the products on display to rise, due to radiance.
  • a light-detector 38 suitable to detect the quantity of infrared "L” striking the products on display, and to transmit the values detected to the control unit 18.
  • the light-detector 38 is installed on the same plane on which the tray 39 lies, so as to detect, in a credible manner, the actual quantity of infrared "L” striking the ice-cream contained therein, so that it is possible to detect the real variation in the temperature of the product with a reasonable degree of reliability.
  • the control unit 18 is suitable to pilot the cooling assembly 40 of the showcase 10, a signalling assembly and protection means 42, such as photochromic glass, movable screens or similar, suitable to defend the products on display from the light "L".
  • a signalling assembly and protection means 42 such as photochromic glass, movable screens or similar, suitable to defend the products on display from the light "L".
  • the cooling assembly 40 works with forced air circulation and is normally controlled by a thermoregulator 43, also functionally connected to the control unit 18, suitable to detect the parameters relating to the thermostat setting of the cooling air circulating inside the showcase 10 and to transmit them to the unit 18.
  • the values supplied at outlet from the light-detector 38 are acquired continuously by the control unit 18, which conditions the functioning of the cooling assembly 40 according to said values.
  • the thermostat setting is modified, lowering the temperature of the air by a value correlated to the quantity of infrared detected.
  • this value can be lowered, for example to -22°C, if the light-detector 38 detects a quantity of infrared such as to significantly raise the temperature of the product.
  • the invention instead of or in combination with the lowering of the temperature setting, provides to increase the speed of the fan 40a in order to increase the intensity of heat exchange between cooling air and refrigerated products, so that the increase in temperature caused by the light "L" is efficiently combated.
  • the increase in speed of the fan 40a is timed.
  • the speed of the fan 40a is increased until the thermoregulator 43 detects a temperature value equal to that required, but with a defined correction factor added.
  • the correction factor is calculated by the control unit 18, using defined algorithms, according to values supplied continuously by the light-detector 38 and is such as to ensure that the products on display have the thermostat parameters required by the legislation in force and necessary for perfect preservation.
  • the control unit 18 activates the signalling assembly 41, which can comprise visual signallers 41a, for example a display, lamps, leds or otherwise, or acoustic signalling means 41b such as a buzzer or similar, or even signalling means of a mixed type.
  • the control unit 18 can also activate the optional protection means 42 chosen on each occasion according to the use of the showcase 10 or where the showcase 10 is installed.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Defrosting Systems (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
EP00100725A 1999-01-15 2000-01-14 Verfahren und Vorrichtung zum Steuern der Kältebedingungen in Kühleinheiten Withdrawn EP1020149A3 (de)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
IT1999UD000005 IT1310521B1 (it) 1999-01-15 1999-01-15 Metodo per il controllo dei parametri di termostatazione inimpianti frigoriferi e circuito elettrico di controllo
IT1999UD000007 IT1310523B1 (it) 1999-01-15 1999-01-15 Metodo per il controllo dei cicli di sbrinamento di impiantifrigoriferi e dispositivo concretizzante tale metodo
ITUD990007 1999-01-15
ITUD990005 1999-01-15
IT1999UD000006 IT1310522B1 (it) 1999-01-15 1999-01-15 Metodo per il controllo dei dispositivi antiappannamento dei vetridi impianti frigoriferi e circuito elettrico concretizzante tale
ITUD990006 1999-01-15

Publications (2)

Publication Number Publication Date
EP1020149A2 true EP1020149A2 (de) 2000-07-19
EP1020149A3 EP1020149A3 (de) 2000-11-02

Family

ID=27274214

Family Applications (1)

Application Number Title Priority Date Filing Date
EP00100725A Withdrawn EP1020149A3 (de) 1999-01-15 2000-01-14 Verfahren und Vorrichtung zum Steuern der Kältebedingungen in Kühleinheiten

Country Status (1)

Country Link
EP (1) EP1020149A3 (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1016842C2 (nl) * 2000-12-11 2002-06-13 Edwin De Koeijer IJsmachine tenminste omvattende een samenstel van een ijsbereidingsinrichting en een ijsvitrine.
WO2007072523A1 (en) * 2005-12-19 2007-06-28 Ixfin S.P.A. System for automated defrosting of a refrigerating apparatus
WO2013007618A3 (de) * 2011-07-14 2013-07-25 BSH Bosch und Siemens Hausgeräte GmbH No-frost kältegerät und verfahren zum abtauen eines verdampfers
ITUB20160124A1 (it) * 2016-01-20 2017-07-20 Paolo Soffientini Macchina per la mantecazione ed esposizione di gelati freschi, sorbetti, granite e prodotti simili
EP2578968A4 (de) * 2010-05-26 2017-08-30 Mitsubishi Electric Corporation Kälte-klimaanlage
RU2649853C2 (ru) * 2013-05-21 2018-04-05 Либхерр-Хаусгерете Линц Гмбх Холодильный и/или морозильный аппарат
IT201700003447A1 (it) * 2017-01-13 2018-07-13 Tommaso Pernici Mantecatore per gelato
CN111265070A (zh) * 2020-01-14 2020-06-12 刘红亮 一种快餐店菜品展示区用橱窗
CN114644179A (zh) * 2022-03-04 2022-06-21 刘晓岩 一种中药制备过程温度监控系统
CN117190526A (zh) * 2023-08-23 2023-12-08 珠海格力电器股份有限公司 一种制冷组件与制冷设备及其控制方法
CN117407634A (zh) * 2023-10-18 2024-01-16 中国空气动力研究与发展中心计算空气动力研究所 一种基于结霜特征曲线的平板结霜厚度快速预测方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA844775A (en) * 1967-11-09 1970-06-16 H. Ting Youn Defrost control apparatus
US3777505A (en) * 1971-07-21 1973-12-11 Mitsubishi Heavy Ind Ltd Defrosting method and apparatus
US3892947A (en) * 1974-02-27 1975-07-01 Donnelly Mirrors Inc Electrically heated panel with anti-shock conductive strips
DE3722349C1 (de) * 1987-07-07 1988-04-07 Flachglas Ag Verfahren zum Entfernen des innenseitigen,die Transparenz beeintraechtigenden Kondensationsbeschlages auf der Verglasung eines Kuehlmoebels und Kuehlmoebel zur Durchfuehrung des Verfahrens
GB9509734D0 (en) * 1995-05-13 1995-07-05 Hussmann Europ Ltd Refrigeration equipment

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002047516A1 (en) * 2000-12-11 2002-06-20 Van Houtven, Marc Ice cream unit comprising at least an ice cream maker combined with an ice cream display cabinet
US6868687B2 (en) 2000-12-11 2005-03-22 Marc van Houtven Ice cream unit comprising at least an ice cream maker combined with an ice cream display cabinet
NL1016842C2 (nl) * 2000-12-11 2002-06-13 Edwin De Koeijer IJsmachine tenminste omvattende een samenstel van een ijsbereidingsinrichting en een ijsvitrine.
WO2007072523A1 (en) * 2005-12-19 2007-06-28 Ixfin S.P.A. System for automated defrosting of a refrigerating apparatus
EP3330642A1 (de) * 2010-05-26 2018-06-06 Mitsubishi Electric Corporation Kälte-klimaanlage
US10222115B2 (en) 2010-05-26 2019-03-05 Mitsubishi Electric Corporation Refrigerating and air-conditioning apparatus
EP2578968A4 (de) * 2010-05-26 2017-08-30 Mitsubishi Electric Corporation Kälte-klimaanlage
EP3330643A1 (de) * 2010-05-26 2018-06-06 Mitsubishi Electric Corporation Kälte-klimaanlage
EP3330640A1 (de) * 2010-05-26 2018-06-06 Mitsubishi Electric Corporation Kälte-klimaanlage
EP3330641A1 (de) * 2010-05-26 2018-06-06 Mitsubishi Electric Corporation Kälte-klimaanlage
WO2013007618A3 (de) * 2011-07-14 2013-07-25 BSH Bosch und Siemens Hausgeräte GmbH No-frost kältegerät und verfahren zum abtauen eines verdampfers
RU2649853C2 (ru) * 2013-05-21 2018-04-05 Либхерр-Хаусгерете Линц Гмбх Холодильный и/или морозильный аппарат
ITUB20160124A1 (it) * 2016-01-20 2017-07-20 Paolo Soffientini Macchina per la mantecazione ed esposizione di gelati freschi, sorbetti, granite e prodotti simili
EP3195732A1 (de) * 2016-01-20 2017-07-26 Paolo Soffientini Maschine zum chargengefrieren und ausstellen von frischen eiscremes, sorbets, brucheis und ähnlichen produkten
IT201700003447A1 (it) * 2017-01-13 2018-07-13 Tommaso Pernici Mantecatore per gelato
CN111265070A (zh) * 2020-01-14 2020-06-12 刘红亮 一种快餐店菜品展示区用橱窗
CN114644179A (zh) * 2022-03-04 2022-06-21 刘晓岩 一种中药制备过程温度监控系统
CN114644179B (zh) * 2022-03-04 2024-04-12 黑龙江职业学院(黑龙江省经济管理干部学院) 一种中药制备过程温度监控系统
CN117190526A (zh) * 2023-08-23 2023-12-08 珠海格力电器股份有限公司 一种制冷组件与制冷设备及其控制方法
CN117407634A (zh) * 2023-10-18 2024-01-16 中国空气动力研究与发展中心计算空气动力研究所 一种基于结霜特征曲线的平板结霜厚度快速预测方法
CN117407634B (zh) * 2023-10-18 2024-05-03 中国空气动力研究与发展中心计算空气动力研究所 一种基于结霜特征曲线的平板结霜厚度快速预测方法

Also Published As

Publication number Publication date
EP1020149A3 (de) 2000-11-02

Similar Documents

Publication Publication Date Title
US7367198B2 (en) Method of control for a refrigerated merchandiser
AU724798B2 (en) Refrigeration system and method of control
US10655904B2 (en) Merchandiser including frame heaters
EP1020149A2 (de) Verfahren und Vorrichtung zum Steuern der Kältebedingungen in Kühleinheiten
KR100455873B1 (ko) 냉각 수납부용 마이크로프로세서 제어식 주문형 제상
US4993233A (en) Demand defrost controller for refrigerated display cases
EP2520880B1 (de) Kühlbox
US10178918B2 (en) Anti-fog heat control for a refrigerated merchandiser
JPH0146771B2 (de)
US5729990A (en) Refrigeration system
JP4894536B2 (ja) 冷却装置
KR20030081927A (ko) 냉장 쇼케이스
JP2001153532A (ja) オープンショーケース
WO2004075693A1 (en) Refrigerated display merchandiser with variable air curtain
CN107664371A (zh) 制冷器具及其控制方法
JP3654412B2 (ja) 冷蔵ショーケースの冷却装置
AU2008226387B2 (en) A refrigeration control system
JP2934747B2 (ja) ショーケースの温度制御方法
KR200283650Y1 (ko) 냉장 쇼케이스
EP3726167B1 (de) Steuerungsverfahren zur steuerung der vereisung eines verdampfers in einem blaskühler
JP7201466B2 (ja) 冷却貯蔵庫
JP3296338B2 (ja) ショーケースの除霜制御装置
KR100208368B1 (ko) 냉장고 및 그 제상제어방법
JPH05296646A (ja) ショーケースの除霜制御装置
JPH11248334A (ja) 自動販売機の制御装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL;LT;LV;MK;RO;SI

17P Request for examination filed

Effective date: 20010208

AKX Designation fees paid

Free format text: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17Q First examination report despatched

Effective date: 20021119

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20030531