Classifications

• • 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
  • F25B29/00—Combined heating and refrigeration systems, e.g. operating alternately or simultaneously
  • F25B29/003—Combined heating and refrigeration systems, e.g. operating alternately or simultaneously of the compression type system
• • 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
  • F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
  • F25B47/02—Defrosting cycles
  • F25B47/022—Defrosting cycles hot gas defrosting
• • 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
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/07—Details of compressors or related parts
  • F25B2400/075—Details of compressors or related parts with parallel compressors
• • 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
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/16—Receivers
• • 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
  • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
  • F25B2400/22—Refrigeration systems for supermarkets
• • 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
  • F25B2600/00—Control issues
  • F25B2600/02—Compressor control

Definitions

• the present invention relates to the technical field of refrigerating plants used to provide refrigeration of various products and in particular food products.
• a refrigeration system comprising high and low pressure refrigerant circuits connected to one or more refrigeration units such as a cabinet or a cabinet. refrigerated showcase or a cold room.
• the refrigeration plant further comprises a compression unit which draws the refrigerant from the low pressure circuit and delivers it compressed into the high pressure circuit.
• the installation further comprises, downstream of the compression unit, an external condenser at which the refrigerant is cooled before being redirected to the refrigeration unit or an intermediate storage tank.
• Such an installation gives full satisfaction with regard to its preservation function at low setpoint temperatures of fragile products or foodstuffs.
• the external dissipation of the heat extracted at the refrigeration units and resulting from the work of the compression group constitutes a dry energy loss which, taking into account the energy costs and the requirements of sustainable development, is not satisfactory.
• an application EP 0 431 797 proposed to adapt, in a heater, a condensation circuit fed with high-pressure gas refrigerant so as to recover the heat for heating premises .
• the installation proposed by the application EP 0 431 797 does not It does not provide enough heat to ensure adequate heating in winter alone.
• An application EP 1 921 401 then proposed a refrigeration plant whose extracted heat is recovered for heating a heat accumulator which is in connection with a central heating water circuit and / or a hot water circuit. health.
• the installation, according to the application EP 1 921 401 furthermore comprises an external evaporator which makes it possible, during the winter period, to take outside the additional heat necessary to satisfy the heating requirements.
• the heat extracted by the installation according to EP 1 921 401 is largely discharged at an external condenser completely independent of the external evaporator.
• this installation makes it possible to obtain additional heat under satisfactory conditions through heat pump operation, it nevertheless has the drawback of not offering sufficient power to cover the heating requirements of the premises so that it is provided complementary electric heating means which penalizes the environmental performance of the installation.
• this installation provides for a defrosting of the external evaporator by cycle inversion, which also affects the performance of the installation in that the design of the outdoor evaporator must then result from a compromise between its operating modes. in evaporator and condenser.
• the application EP 1 921 401 provides for placing the indoor heat exchanger for heating in series with the external condenser and upstream of the latter, which penalizes the energy efficiency of the installation and requires the implementation of a large amount of liquid refrigerant to fill the circuit downstream of the heat exchanger when the refrigerant is fully condensed therein.
• a new type of refrigeration plant that allows, on the one hand, to recover at least a portion of the heat available in the refrigerant for heating premises and, on the other hand, to possibly supplement this heat input in economically and ecologically satisfactory conditions and which has, moreover, equivalent electrical power absorbed performance superior to those known refrigeration installations and lower maintenance costs.
• the invention relates to a refrigerant refrigerant installation comprising at least:
• a refrigeration unit comprising at least one evaporator arranged in a cabinet or a refrigerating chamber and connected to the high and low pressure circuits,
• an air conditioning unit comprising at least one exchanger which is arranged inside a room and which comprises at least one condenser connected to the high and low pressure circuits,
• an outdoor unit comprising at least one air exchanger which is arranged outside and which comprises a condensation circuit connected to the high and low pressure circuits,
• control unit that controls at least the operation of the installation.
• the refrigerating unit is characterized in that:
• the air exchanger of the outdoor unit comprises: a tubular evaporation circuit adapted to be fed only with low pressure refrigerant and connected to the high and low pressure circuits,
• thermally conductive fins connecting the tubular evaporation circuit and the tubular condensation circuit being integral with the tubular evaporation and condensation circuits, the tubular condensation circuit being adapted to be fed only with high pressure refrigerant and sized to dissipate all the heat resulting from the maintenance, at each refrigeration unit, of the set temperatures when outside a summer temperature,
• control unit is adapted to place the installation:
• the compression units are dimensioned so that their cumulative powers are sufficient to maintain, at each refrigeration unit, the set temperatures when outside a summer temperature and the installation is in pure refrigeration mode .
• Such a refrigeration plant according to the invention is particularly suitable for cooling the refrigeration units and for heating a room with the heat recovered at the refrigeration units and resulting from the compression of the refrigeration unit.
• Refrigerant In this regard, the implementation of an auxiliary compression group allows, when the heat recovered at the refrigeration units is not sufficient to heat the room satisfactorily, to take out the missing heat and necessary to reach the satisfactory heating level.
• the exchanger of each air conditioning unit can be of any suitable nature.
• the exchanger of each air conditioning unit, or of certain units only can be an exchanger for heating a heat transfer liquid, such as for example but not exclusively, the water of a heating circuit, or sanitary water.
• the exchanger of each air conditioning unit, or some units only can also be an air heat exchanger also called air heater.
• the implementation of such an air exchanger has the advantage of directly heating the air without implementation of an intermediate heat transfer fluid and provides optimal performance and simplify the implementation and the operation of the refrigeration plant according to the invention.
• the installation according to the invention is also likely to implement several air conditioning units having different types of exchangers.
• the high and low pressure circuits can comprise a main high pressure circuit, a secondary high pressure circuit and a main low pressure circuit.
• the evaporator of the air conditioning unit will then be supplied with refrigerant by the main high pressure circuit via a pressure reducer and connected to the main low pressure circuit.
• the evaporation circuit of the outdoor unit will be fed by the main high pressure circuit via a holder and connected to an auxiliary low-pressure circuit while the condensation circuit of the outdoor unit is connected to the main high-pressure circuit upstream. evaporators.
• the main compression unit will draw the refrigerant from the main low pressure circuit and drive the compressed refrigerant back into the main high pressure circuit while the auxiliary compression unit draws the refrigerant from the auxiliary low pressure circuit and delivers the compressed refrigerant into the compressor.
• main high pressure circuit The main compression unit will draw the refrigerant from the main low pressure circuit and drive the compressed refrigerant back into the main high pressure circuit while the auxiliary compression unit draws the refrigerant from the auxiliary low pressure circuit and delivers the compressed refrigerant into the compressor. main high pressure circuit.
• the installation may also include a controlled isolation valve for opening or closing the communication between the auxiliary low-pressure circuit and the evaporation circuit of the external exchanger, as well as a branch circuit which connects the main low-pressure circuit. to the secondary low pressure circuit and which is equipped with a controlled bypass valve to open or close the bypass circuit.
• the control unit is then adapted to:
• control unit is adapted to switch from the mixed mode of operation to the mode of operation of pure refrigeration and vice versa depending on refrigeration needs.
• the installation comprises defrosting means of the exchanger of the outdoor unit adapted to ensure, in the context of the mixed mode operation of the installation, the temporary supply of the condensation circuit of the outdoor unit.
• de-icing means makes it possible to preserve the efficiency of the external heat exchanger, especially when the latter is used as a source of heat in the winter period.
• the use of the condensation circuit, designed to withstand high pressures, of the refrigerant makes it possible to avoid resorting to a cycle reversal defrosting at the level of the evaporation circuit, which has the advantage, on the one hand, of not having to size the evaporation circuit for high pressures, on the other hand, to avoid subjecting the evaporation circuit to thermal shock resulting from a rapid transition from a negative temperature to a positive temperature, by for example, more than 30 ° and, moreover, to avoid the risks of suction of liquid during the restart in heat pump.
• the fins connecting the condensation and evaporation circuits dampen the differences in expansion between the condensation and evaporation circuits during deicing phases, thus reducing the mechanical stresses experienced by these circuits.
• the invention makes it possible, by separating the evaporation and condensation circuits of the outdoor unit, to optimize their dimensioning for their nominal operating speed with correct pressure losses, controlled fluid velocities allowing a good oil return which contributes to the performance of the entire refrigeration
• the installation comprises:
• the control unit is adapted to control the opening of a valve supply of the condensation circuit when the frost on the exchanger exceeds a certain threshold.
• the detection of frost can be carried out in different ways, for example by monitoring the load of a forced ventilation motor of the exchanger to deduce from the increase in the engine load an appearance of frost on the exchanger.
• the frost evaluation means comprise means for measuring the humidity of the air entering and leaving the exchanger.
• control unit is adapted to control a reversal of the operating direction of a extractor fan equipping the external exchanger at the end of defrosting thereof. This inversion of rotation makes it possible to obtain optimal drying of the exchanger of the outdoor unit.
• the plant can be adapted to activities requiring several levels of cold such as, for example, activities where it is necessary to keep fresh products at positive temperatures as well as products frozen at negative temperatures.
• the refrigeration plant according to the invention then comprises:
• a secondary refrigeration unit comprising at least one evaporator arranged in a piece of furniture or a cold room and supplied with refrigerant by the main high pressure circuit via a pressure reducer and connected to the secondary low pressure circuit,
• a secondary compression group which sucks the refrigerant from the secondary low pressure circuit and which discharges the compressed refrigerant into the main high pressure circuit, the control unit being adapted to control the operation of the secondary compression group.
• the implementation of the secondary compression group discharging the compressed refrigerant in the same high-pressure main circuit as the other compression groups makes it possible to use all of the thermal energy recovered by all the compression groups to ensure heating the premises where the unit heaters are located.
• the auxiliary compression group power is not sufficient to ensure the cooling of the room under summer outdoor temperature conditions.
• At least one heater of the air conditioning unit is adapted to be reversible and operate as a condenser or evaporator, and the installation comprises means for supplying refrigerant each unit heater operating as an evaporator .
• the auxiliary compression group has sufficient power to ensure the cooling of the room with a summer outdoor temperature.
• the invention also relates to an air exchanger for a refrigeration plant according to the invention, this air exchanger comprises:
• tubular condensation circuit adapted to be fed only with high-pressure refrigerant
• tubular evaporation circuit adapted to be fed only with low pressure refrigerant
• the condensation circuit has a sufficient exchange power to ensure heat dissipation in the summer period, that is to say that the absolute value of the thermal power of the tubular condensation circuit is greater than or equal to to the absolute value of the thermal power of the evaporation tubular circuit.
• the exchanger according to the invention has the advantage of having an evaporation circuit separate from the condensation circuit so that each of these circuits is perfectly sized to optimally ensure its function of condenser or evaporator at the difference of a heat exchanger whose circuit would be adapted to have a mixed operation either in condenser or in evaporator.
• the design of the exchanger according to the invention therefore allows it to obtain optimum energy efficiency.
• the use of vanes common to the evaporation and condensation circuits makes it possible to optimize the heat exchanges during the defrosting phase, the duration of which can then be shortened compared to the defrosting time in the context of a defrosting mode. construction that would consist of simply juxtapose one above the other a condenser and an evaporator.
• the fins provide mechanical damping of the differential expansion phenomena during the defrosting phases.
• the thermal power of the tubular condensation circuit has a value of between 1 and 5 times the absolute value of the thermal power of the evaporation tubular circuit.
• the exchange surface of the tubular condensation circuit has between 50% and 80% of the sum of the exchange surfaces of the condensation and evapo ration tubular circuits.
• the condensation circuit under normal conditions of use the condensation circuit is located at least partly below the evaporation circuit. This arrangement makes it possible to take advantage of the convection phenomena to accelerate the defrosting of the evaporation circuit.
• the condensation and evaporation circuits comprise loops or sheets of tubes and certain loops or layers of the evaporation circuit are superimposed and interposed between loops or layers of the condensation circuit. .
• the fins have a substantially vertical orientation.
• the evaporation and condensation circuits have rectilinear main tubes which are inclined by a few degrees with respect to the horizontal, which favors the runoff of the water.
• the condensation circuit comprises at least one tube ply which forms the first ply of tube starting from the bottom of the exchanger. This first sheet of tube advantageously forms a surface on which a portion of the water present in the air will condense or settle, thereby reducing the charge of the air circulating in the exchanger and thus reducing the speed of Frost appears on the evaporation circuit.
• the heat exchanger comprises at least one electric fan ensuring a forced circulation of air in the exchanger.
• the various features, variants, shapes and embodiments of the plant and / or the exchanger can be associated with each other in various combinations to the extent that they are not incompatible or exclusive of each other. .
• Figure 1 is a schematic view of a refrigeration plant according to the invention.
• FIG. 2 is a longitudinal section of a heat exchanger according to the invention that can be implemented as part of the installation illustrated in FIG.
• FIG. 3 is a cross-section of the exchanger along line III-III of FIG. 2.
• FIG 4 is a schematic view of another embodiment of a refrigeration plant according to the invention.
• a refrigeration plant according to the invention as illustrated in Figure 1 and generally designated by the reference 1, comprises a main high pressure circuit 2 of refrigerant on which is disposed a high pressure tank 3 from which extends a branch 2 a high pressure refrigerant fluid supply of at least one and usually several main refrigeration units R p.
• Such a refrigeration unit R p comprises at least one evaporator disposed in a piece of furniture or a refrigerating chamber.
• the refrigerating installation 1 also comprises at least one or according to the example illustrated three air conditioning units 5 arranged inside one or more premises.
• each air conditioning unit comprises at least one air exchanger or air heater equipped with at least one condenser 6 which is connected to the main high pressure circuit 2 upstream of the evaporators of the refrigeration units R p and, according to illustrated example, also upstream of the tank 3 of high pressure refrigerant.
• the installation 1 further comprises a main compression unit 10 which sucks the refrigerant from the main low pressure circuit 4 to discharge it compressed into the main high pressure circuit 2 upstream of the condensers 6, the high pressure reservoir 3 and, of course , evaporators that it feeds.
• the main compression unit 10 comprises at least one and, according to the illustrated example, three compressors 11 connected in parallel to the high pressure 2 and low pressure circuits 4. The operation of the compression unit 10 is then controlled by a control unit 12.
• the refrigeration system operates in the following manner.
• Each main refrigeration unit R p is provided with a self-regulating device, it controls the opening of a valve supplying its evaporator high pressure refrigerant via a regulator as necessary to maintain within it a set temperature .
• the operation of the refrigeration unit induces a pressure increase in the main low pressure circuit 4 that the control unit 12 detects to trigger the operation of the main compression unit 10 which then sucks the low pressure refrigerant into a gaseous state low pressure to discharge it in the gaseous state high pressure in the main high pressure circuit 2.
• the refrigerant is within the main high pressure circuit 2 in the gaseous state and at a high temperature of
• the invention proposes to use the heat of the high-pressure gas refrigerant to heat one or more rooms by means of the air heaters 5 whose condensers 6 are fed by valves. 13 controlled by the control unit 12.
• the air heaters 5 whose condensers 6 are fed by valves. 13 controlled by the control unit 12.
• the refrigerant will be in the high pressure liquid state.
• the heat recovered at the refrigeration units can, in some cases especially in winter, not be sufficient to heat the premises to an acceptable or even comfortable setpoint temperature.
• Winter period means a period during which the average outdoor temperature is below 18 ° C.
• the invention then proposes to take away the heat or missing calories.
• an outdoor unit 15 is implemented comprising at least one heat exchanger 17 which comprises an evaporation circuit 18 connected to the main high pressure circuit 2 via a pressure reducer 19.
• the evaporation circuit 18 is also connected to an auxiliary low-pressure circuit 20 which supplies an auxiliary compression unit 21.
• the auxiliary compression unit 21 comprises at least one and, according to the illustrated example, two compressors 22 which are connected in parallel to the auxiliary low-pressure circuit 20 and to the circuit 2.
• the auxiliary compression unit 20 then draws via the auxiliary low-pressure circuit 20 the refrigerant in the gaseous state from the evaporator 18 of the exchanger 17 to compress it and pump it back into the main circuit 2.
• the auxiliary compression group 20 is then driven by the unit of controls 12 which modulates the operation of one or both compressors 22 as needed.
• the auxiliary compression unit 21 and the external heat exchanger 5 operate in a heat pump and take the external heat necessary to maintain the set temperature in the rooms by means of the air conditioning units 5.
• the refrigeration system according to the invention allows to ensure alone, in a mixed operating mode refrigeration / heat pump, on the one hand the cooling of the refrigeration units and, on the other hand, the heating of the premises. Such a mixed mode of operation therefore allows for significant energy savings for space heating.
• the evaporator 16 Insofar as the temperature at the surface of the evaporator 18 is negative in view of the expansion of the refrigerant within it, after a certain operating time, the evaporator 16 will be covered with frost resulting from the condensation and the freezing of the water present in the external atmosphere. It is therefore necessary to ensure defrosting of the condenser 18 on a regular basis.
• the invention proposes to carry out this defrosting by using the heat of the refrigerant compressed at the outlet of the compression groups.
• the invention proposes to associate a condenser 25 to the evaporator 18.
• the condenser 25 supplied with high pressure refrigerant gas by the main high pressure circuit 2 by being connected thereto, on the one hand, downstream of the groups compression and, secondly, upstream of the tank 3 and the evaporators of the main refrigeration units R p .
• the evaporator 18 comprises a tubular circuit 30 for evaporating the refrigerant formed by tube plies 32 comprising rectilinear main tubes, as shown more particularly in FIG. 2.
• the condenser 25 comprises a tubular circuit for condensing the fluid refrigerant which consists of webs 35 of tubes 36 having rectilinear main tubes as shown in Figure 2.
• the tubular circuits 30 and 35 are then interconnected by thermally conductive fins 40 which have, according to the illustrated example, a substantially vertical orientation.
• the thermal conduction link provided by the fins 40 which are common to the evaporation and condensation circuits 35 guarantees a very high efficiency of the defrosting.
• the tube sheets of the condensation and evaporation circuits are superimposed and interposed between each other.
• the first ply of the exchanger 17 from the bottom is formed by tubes of the condensation circuit so as to form a condensation surface of the water vapor present in the air during Of the operation of the outdoor unit 15.
• the exchanger 17 is located inside a chassis frame 41 equipped in the upper part of at least one and, according to the illustrated example, two fans 43 forcing the circulation of air inside the outdoor unit 15.
• the rectilinear parts of the tubes and the fins may be inclined relative to the horizontal respectively the vertical angle ⁇ a few degrees, for example from 3 ° to 5 °. This inclination can be obtained by the inclination of the entire chassis.
• the installation may include a branch 55 connecting the outlet of the auxiliary compression unit 21 upstream of the suction of the main compression unit 10 via a constant pressure valve 56 controlled by the unit 12.
• the condenser 25 is used regularly to defrost the evaporator 18. This regular operation can be provided according to a predefined time interval regardless of the possible occurrence of frost on the evaporator 18 or on the contrary depending on the needs in case of actual appearance of frost or the forecast of the appearance of frost.
• the refrigerating plant 1 can implement means for evaluating the ice.
• frost evaluation means may be formed in any suitable manner.
• the frost evaluation means may comprise means 45 for monitoring the load of the fans 43 which, when the latter exceeds a predetermined threshold, deduce the appearance of frost. Indeed, the frost being deposited on the tubes 30 and the fins 40 will progressively obstruct the exchanger 17 making it more difficult the circulation of air so that the load of the fans 43 increases.
• the frost detection means may also include a system that measures the hydrometry of the inlet and outlet air of the outdoor unit 15 to deduce the possible occurrence of frost.
• the frost evaluation means may also include a system for measuring the hydrometry and the outside air temperature, depending on the latter, predicting the appearance of frost.
• the frost evaluation means are connected to the control unit 12 which, when necessary, triggers a defrost cycle. During such a defrosting cycle, the unit 12 controls the supply of the condenser 25 in high pressure refrigerant hot. This supply is provided by a branch of the main high pressure circuit 2 controlled by a valve 46 controlled by the unit 12.
• the valve 46 then allows admission into the supply circuit of the condenser 25 of high pressure refrigerant gas directly compression groups 10 and 21.
• a bypass line 47 for sampling high pressure refrigerant downstream of the tank 3.
• the bypass 47 is then controlled by a valve 48 controlled by the unit 12.
• the control valves 46 and 48 then ensures a mixture between high pressure gas from the compression groups and the high pressure fluid from the reservoir 3 to modulate the temperature of the fluid within the condenser 25 to bring the condenser and fins progressively from a negative temperature to a temperature positive higher but lower than the temperature of the refrigerant gas compressed at the output of the compression groups.
• the unit 12 can maintain the temperature of the refrigerant supplying the condenser 25 to values of the order of 40 ° to 60 ° while the maximum temperature at the output of the compression groups is of the order of 80 0 C. such a gradual rise of the temperature avoids subjecting the exchanger 15 an excessive thermal shock.
• the unit 12 can also control the operation of the fans 41 so as to blow down the outside air to contribute to the drying of the exchanger 17.
• the auxiliary compression unit 21 is used to extract heat from the outside environment.
• the auxiliary compression group 21 may be used in reinforcement of the main compression group to compress the refrigerant gas from refrigeration units R p .
• the refrigeration system comprises a bypass circuit 50 connecting the main low pressure circuit 4 to the auxiliary low pressure circuit 20 via a controlled valve 51 by the unit 12.
• the auxiliary low pressure circuit 20 comprises also upstream of the junction with the bypass 50 a valve 52 controlled by the unit 12.
• the unit 12 controls the closing of the valve 52 and the opening of the valve 51 and the operation of the auxiliary compression group 21 as needed.
• the power of the latter will then be available for refrigeration, the condenser 25 being further dimensioned to allow external evacuation of the heat extracted at the refrigeration units R p .
• the power of the condenser 25 is then greater than or equal to the power of the evaporator 18.
• the thermal power of the condensation tubular circuit 25 may for example have a value between 1 to 5 times the absolute value of the thermal power of the evaporation tubular circuit 18. This power ratio can be obtained by producing the exchanger 17 of the outdoor unit 15 so that the exchange surface of the condensation tubular circuit 25 has between 50% and 80 % of the sum of the exchange surfaces of the condensation and evaporation tubular circuits 18.
• the valves 45 and 47 will be closed and the supply of the condenser 25 will be provided by a valve 53 at constant pressure controlled by the unit 12.
• the evaporator 18 will not be supplied with refrigerant and the valve and the valve 19 will be closed.
• the ability of the installation according to the invention to operate in mixed mode or in pure refrigeration mode allows to size the main compression group 10 and auxiliary 21 with a cumulative power just sufficient to ensure optimal refrigeration in summer. Summer is defined as a period during which the average daytime temperature is above 18 ° C. Since, in winter, the power required to ensure adequate refrigeration is lower than that required during the summer period, the residual power available at the auxiliary compression group 21 may advantageously be used, in winter, for operation in winter. heat pump for space heating.
• the refrigeration unit comprises only low and high pressure main circuits which supply refrigeration units operating in the same temperature ranges, either positive or negative.
• a refrigeration plant according to the invention may have to supply positive temperature refrigeration units and negative temperature refrigeration units.
• an installation according to the invention may also comprise at least one secondary refrigeration unit R s comprising at least one evaporator disposed in a cabinet or a refrigerated premises supplied with refrigerant by the high circuit main pressure 2 downstream of the tank 3.
• the evaporator of the secondary refrigeration unit R s is connected to a secondary low pressure circuit 60 which supplies a secondary pressure group 61 drawing the refrigerant from the secondary low pressure circuit 60 to discharge in the main high pressure circuit 2.
• the secondary compression group 61 then comprises at least and, according to the example, two compressors 62 which are controlled by the control unit 12.
• the operation of the refrigeration plant according to the invention comprising such a secondary low pressure circuit 60 and a secondary compression group 61 is then substantially similar to that described previously with regard to the modes of mixed operation and pure refrigeration.
• the refrigerating installation comprises a liquid exchanger 63 connected on the one hand to the high-pressure circuit 2 in parallel with the exchangers 5 and on the other hand to a circulation circuit 64. a heat transfer liquid.
• the liquid exchanger 63 whose supply is controlled by a valve 65 controlled by the control unit UC, then allows heating of the liquid of the circuit 64.
• the condenser 25 is placed on the main high pressure circuit 2 in parallel with the exchangers 6 and / or 63.
• suction lines 67 and 68 controlled by valves 68 and 69 controlled by the unit 12.
• the suction lines 67 and 68 are further connected, via an expansion member 70, the main low pressure circuit 4 just upstream of the main compression group 10. This arrangement reduces the amount of refrigerant implemented by the installation compared to facilities where no partial emptying of the liquid phase is possible.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Devices That Are Associated With Refrigeration Equipment (AREA)
• Cooling Or The Like Of Electrical Apparatus (AREA)
• Other Air-Conditioning Systems (AREA)
• Defrosting Systems (AREA)
• Devices For Blowing Cold Air, Devices For Blowing Warm Air, And Means For Preventing Water Condensation In Air Conditioning Units (AREA)

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• 2008
  • 2008-07-03 FR FR0854525A patent/FR2933484A1/fr not_active Withdrawn
• 2009
  • 2009-07-03 PL PL09772753T patent/PL2310769T3/pl unknown
  • 2009-07-03 EP EP09772753A patent/EP2310769B1/de not_active Not-in-force
  • 2009-07-03 AT AT09772753T patent/ATE543059T1/de active
  • 2009-07-03 DK DK09772753.1T patent/DK2310769T3/da active
  • 2009-07-03 US US12/999,446 patent/US20110094250A1/en not_active Abandoned
  • 2009-07-03 WO PCT/FR2009/051311 patent/WO2010001071A2/fr active Application Filing

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