FILLING DEVICE FOR AN AIR CONDITIONER

Description

[0001] The invention relates to a filling device for carrying out a filling process of an air conditioning system of a vehicle with a refrigerant. The filling device includes a receiving area for receiving a pressure vessel filled with the refrigerant, a valve unit connectable to an outlet of the pressure vessel for controlling a quantity of refrigerant that can be supplied to the vehicle, and a heating device for heating the pressure vessel. The invention also relates to a method for carrying out a filling process of an air conditioning system of a vehicle with a refrigerant. The refrigerant is supplied to the vehicle from a pressure vessel, the supplied quantity of refrigerant being controlled via a valve unit connected to an outlet of the pressure vessel, and the pressure vessel being heated to increase the pressure in the pressure vessel.

[0002] When filling a vehicle's air conditioning system, a refrigerant is typically pumped from a pressure vessel into the air conditioning system under controlled conditions. For cost reasons, pumps are not generally used for this purpose; instead, the pressure vessel is heated to increase the internal pressure. This creates a sufficient pressure difference for the refrigerant to flow from the pressure vessel to the air conditioning system. In known filling devices, the pressure vessel is heated to a maximum temperature in the range of 55°C, and the pressure is currently limited to approximately 85 bar. In R744 systems, for example, carbon dioxide (CO2) is used as the refrigerant, which is stored in a replaceable pressure vessel. Standardized pressure cylinders are generally used as pressure vessels and can typically contain quantities of 5 kg to 20 kg or more of the refrigerant CO2.

[0003] Until now, the pressure vessel was usually heated using an electric heating mat, which is placed around the pressure vessel and can be operated with household electricity. A temperature sensor and an additional temperature-dependent safety switch can be integrated into the heating mat. However, the use of a heating mat has several disadvantages. Firstly, it is a relatively expensive solution, which contradicts the aim of providing a cost-effective filling device. Secondly, changing the vessel is complex and time-consuming, since each time the pressure vessel is changed, it is necessary to first remove the heating mat from the empty pressure vessel and then re-attach it to the new, full pressure vessel. Furthermore, there is also the risk that improper handling of the heating mat when changing the vessel (e.g.Poor thermal bonding (e.g., poor thermal bonding between the surface of the heating mat and the surface of the pressure vessel) can lead to errors that may negatively impact filling accuracy or result in a loss of heating performance. In general, due to the thermal and electrical insulation of the heating mat required for safety reasons, only moderate heating performance is achieved, which is also detrimental to efficient and rapid heating of the pressure vessel during operation.

[0004] US 2006 / 0101835 A1 discloses a filling system for filling a cooling system for a vehicle. The system comprises a control unit, a coolant source, and at least one line connecting the coolant source to the cooling system. Furthermore, a control valve is provided that regulates the flow of coolant from the coolant source to the cooling system, as well as an efficiency sensor for measuring the efficiency of the cooling system. Initially, a baseline efficiency of the cooling system is measured at a coolant filling quantity that is below a recommended coolant filling quantity. After filling with an additional amount of coolant, the efficiency is determined again and compared with the baseline efficiency.

[0005] DE 11 2005 001 670 B4 also discloses a coolant filling system and a method for filling a cooling system. The coolant system comprises a coolant source, a storage tank, an inlet and outlet line, and a device for determining the coolant mass inside the storage tank. Furthermore, the coolant system comprises an inlet control valve between the storage tank and the coolant source, an outlet control valve between the storage tank and the cooling system, and a heating device connected to the coolant source to increase the coolant temperature.

[0006] Furthermore, EP 1 143 213 A1 and US 2008 / 0264072 A1 also show a filling device for motor vehicle air conditioning systems and a liquid gas supply device and a supply method.

[0007] It is therefore an object of the invention to enable a simpler and more efficient implementation of filling processes for vehicle air conditioning systems.

[0008] The object is achieved according to the invention with the filling device mentioned above in that the heating device has at least one infrared heating unit for contactless heating of the pressure vessel. The object is further achieved with the method mentioned above in that the pressure vessel is heated contactlessly using at least one infrared heating unit. This enables more efficient heating of the pressure vessel through radiant heat, and the vessel can be changed much more easily and quickly. Furthermore, in contrast to heating mats, no grounding of the infrared heating unit or the pressure vessel is necessary.

[0009] The filling device preferably includes a control unit for controlling the filling process. This allows the filling process to be carried out automatically.

[0010] A scale for measuring the weight of the pressure vessel can optionally be installed in the receiving area. This allows the pressure vessel's weight to be measured during the filling process, and the amount of refrigerant added can be controlled based on the measured weight. This allows the filling process to be carried out with a specified charge.

[0011] The filling device advantageously includes at least one pressure sensor for detecting the pressure of the refrigerant, and / or at least one temperature sensor for detecting the temperature of the pressure vessel and / or the heating device and / or the refrigerant. This allows pressure and temperature to be monitored, and the heating device and / or the valve unit can be controlled depending on the pressure and temperature.

[0012] The filling device can also incorporate multiple infrared heating units, preferably distributed around the circumference of the receiving area. This allows for a larger heating surface, enabling more efficient heating, particularly for pressure vessels with larger diameters.

[0013] It may be advantageous if a shielding unit is provided in the filling device on a side of at least one infrared heating unit facing away from the receiving area, wherein the shielding unit preferably surrounds at least half of the infrared heating unit in the circumferential direction. This allows the heat radiation to be better directed toward the pressure vessel, and also protects sensitive components of the filling device from overheating.

[0014] Preferably, at least one infrared heating unit is elongated and arranged in the filling device such that its longitudinal axis runs parallel to the vertical axis of a pressure vessel arranged vertically in the receiving area. This allows the pressure vessel to be heated over as much of its height as possible.

[0015] A user interface connected to the control unit can also be provided on the filling device, via which control parameters of the filling process can be adjusted, in particular the amount of refrigerant that can be supplied to the air conditioning system and / or the filling time. This enables easy operation of the filling device.

[0016] The filling device can also be designed as a mobile filling device, wherein wheels can be arranged on the underside of the filling device and / or wherein an energy storage device can be provided in the filling device to supply the filling device with energy for carrying out at least one filling process. This allows the filling device to be easily moved between vehicles, for example, in a workshop, and the filling process can be carried out independently of its energy source.

[0017] It may also be advantageous if at least one infrared heating unit is arranged so that it can be moved translationally and / or rotationally relative to the receiving area. This allows, for example, a distance and / or angle between at least one infrared heating unit and the pressure vessel to be changed, for example, to maintain a constant distance regardless of the pressure vessel used. This can be particularly advantageous when using pressure vessels of different sizes.

[0018] The receiving area is preferably designed to accommodate pressure vessels with a cylindrical cylinder body and a cylinder diameter of 15 cm to 40 cm. This allows common standardized pressure cylinders to be used in the filling device.

[0019] Carbon dioxide is the preferred refrigerant. This allows the filling device and process to be used for R-744 air conditioning systems.

[0020] The present invention is described below with reference to the Figuren 1 bis 2 which show exemplary, schematic and non-limiting advantageous embodiments of the invention. Fig.1 the basic structure of a filling device for carrying out a filling process of an air conditioning system of a vehicle, and Fig.2 a filling device for carrying out a filling process of an air conditioning system of a vehicle according to a preferred embodiment of the invention.

[0021] Fig.1 shows schematically the basic structure of a filling device 1 for carrying out a filling process of an air conditioning system of a vehicle F. The filling device 1 has a receiving area 2 for receiving a pressure vessel 3 filled with the refrigerant K, for example carbon dioxide (CO 2 ). The receiving area 2 is in Fig.1 only schematically indicated by the dashed border of the pressure vessel 3 and can essentially be designed as desired. The only essential requirement is that the receiving area 2 is suitable for receiving a pressure vessel 3, preferably for receiving pressure vessels 3 of different sizes (e.g. height and / or diameter). In a simple embodiment, the receiving area 2 can, for example, comprise only a plate for placing the pressure vessel 3. However, the receiving area 2 can also be designed such that the pressure vessel 3 is partially or completely enclosed by a housing 4 of the filling device 1.

[0022] Furthermore, a valve unit 5 is provided in the filling device 1, which can be connected to an outlet 3a of the pressure vessel 3. The valve unit 5 can be used to control the amount of refrigerant K supplied to the vehicle F from the pressure vessel 3. In the simplest case, the valve unit 5 can be manually designed and, for example, manually operated by a user. Preferably, however, the valve unit 5 comprises a controllable actuator, e.g., an electrically controllable servo valve, which can be controlled via a control unit 6. The control unit 6 can be part of the filling device 1, as shown in Fig.1 is indicated. In principle, however, only a suitable interface 7 could be provided in the filling device 1, for example on the housing 4, via which the valve unit 5 can be connected to an external control unit 8, e.g. a computer.

[0023] Furthermore, a heating device 9 for heating the pressure vessel 3 is provided in the filling device 1. As mentioned above, a heating mat was previously used as the heating device 9, which was applied around the circumference of the pressure vessel 3 on the surface of the pressure vessel. The heating mat is in Fig.1 indicated by way of example and can, for example, comprise a number of heating coils 9a, which can be supplied with the necessary energy from a suitable energy source 10, for example a conventional household socket. As mentioned at the beginning, however, the use of the heating mat results in some disadvantages. According to the invention, it is therefore provided that the heating device 9 instead has at least one infrared heating unit 11 in order to heat the pressure vessel 3 without contact. An advantageous embodiment of the filling device 1 according to the invention is described below with reference to Fig.2 explained in more detail.

[0024] The Fig.2 The filling device 1 shown in FIG. 1 again comprises a housing 4 in which a receiving area 2 for a pressure vessel 3 and a valve unit 5 connectable to the outlet 3a of the pressure vessel 3 are located. Advantageously, a plurality of infrared heating units 11 are provided in the filling device 1, which are preferably arranged distributed around a circumference of the receiving area 2. In the example shown, the heating device 9 comprises two infrared heating units 11a, 11b, which are arranged substantially opposite one another on the circumference of the receiving area 2. As shown in FIG. Fig.2 As indicated, the infrared heating units 11a, 11b generate heat radiation S, which is directed onto the surface of the pressure vessel 3 and heats the pressure vessel 3. The opposing arrangement of the infrared heating units 11a, 11b has the advantage, for example, that the pressure vessel 3 can be introduced into the receiving area 2 from the side, essentially horizontally. This is particularly advantageous for pressure vessels 3 with a relatively large filling quantity in the range of 20 l or more, since these have a relatively high weight, particularly when full. For this purpose, a suitable opening (not shown) can be provided in the housing 4, for example, through which the pressure vessel can be introduced into the receiving area 2. The opening could also be closable, for example, by a cover or a door.If additional infrared heating units 11 are provided on the perimeter of the receiving area 2, then the pressure vessel 3 could also be introduced into the receiving area 2, for example, from above.

[0025] The infrared heating units 11a, 11b can, for example, be elongated and arranged in the filling device 1 such that their longitudinal axes run essentially parallel to a vertical axis of a pressure vessel 3 arranged in the receiving area 2, as shown in Fig.2is indicated. Preferably, the receiving area 2 is designed to receive pressure vessels 3 with a cylindrical bottle body with a bottle diameter of 15 cm to 40 cm. This means that common standardized pressure bottles can be used. Particularly when using pressure vessels 3 with a relatively small diameter in relation to the height (and thus a relatively high center of gravity), it can also be advantageous if the receiving area 2 is designed such that the pressure vessel 3 arranged therein is secured against falling over. For this purpose, for example, a suitable catch device (not shown) can be provided which secures the pressure vessel 3 against unwanted tipping. For example, a preferably pivotable strut in the area between the infrared heating units 11a, 11b or one or more preferably resealable straps would be conceivable.If a scale 13, which will be described in more detail below, is provided in the receiving area 2, then any catch device present should in any case be designed in such a way that the pressure vessel 3 is reliably prevented from falling over, but that the pressure vessel 3 nevertheless stands sufficiently freely on the scale 13 so that the weight can be measured as accurately as possible.

[0026] A shielding unit 12 is provided on each of the infrared heating units 11a, 11b on a side facing away from the receiving area 2. This can, on the one hand, increase the efficiency of the heating, since the heat radiation S generated by the infrared heating units 11a, 11b can be better directed towards the pressure vessel 3. This allows the largest possible part of the surface of the pressure vessel 3 to be covered by the heat radiation S. It can be advantageous if the shielding unit 12 surrounds the respective infrared heating unit 11a, 11b in the circumferential direction, e.g., at least halfway. To ensure uniform irradiation of the surface of the pressure vessel 3, the shielding units 12 can, for example, be parabolically shaped, and the infrared heating units 11a, 11b can be arranged at the respective focal point of the parabolic shielding unit 12.

[0027] In addition to the directed distribution of the heat radiation S, the shielding units 12 can also prevent or at least reduce heat transfer to the other parts of the filling device 1. This allows sensitive components, such as the control unit 6, electrical, pneumatic or hydraulic lines, to be protected from overheating. The shielding units 12 are preferably made of a sufficiently temperature-resistant material, for example a suitable metal and / or plastic. Metal has the advantage that a relatively large portion of the heat radiation S can be reflected and directed towards the pressure vessel 3. Plastic, in turn, has the advantage of lower thermal conductivity, which results in less heat radiation towards the other components of the filling device 1.

[0028] It would therefore also be conceivable, for example, for the shielding units 12 to be made of a suitable plastic and for only the inner side facing the receiving area 2 to be coated with a suitable metal in order to reflect the heat radiation S as effectively as possible. The type and structural design of the shielding unit 12 naturally depends on the number and structural design of the infrared heating units 11. For particularly good thermal insulation, it would also be conceivable for a heat-insulating material to be additionally arranged around the receiving area 2 and the infrared heating units 11a, 11b. For example, an inner side of the housing 4 could be lined with a suitable insulating material. It would also be conceivable for any cables (electrical, hydraulic, pneumatic) to be protected against excessive heating by providing insulation.

[0029] According to an advantageous embodiment, the infrared heating units 11a, 11b can be arranged in the filling device 1 so that they can be moved translationally or rotationally relative to the receiving area 2. This allows, for example, a position X and / or an angle ϕ of the respective infrared heating unit 11a, 11b to be adjusted relative to the receiving area 2 or the pressure vessel 3. Height adjustment would of course also be conceivable. The adjustability is advantageous, for example, when using pressure vessels 3 with different diameters in order to be able to set a distance between the infrared heating units 11a, 11b and the pressure vessel 3. The shielding units 12 could of course also be arranged so that they can be moved. For example, the shielding units 12 could be fixedly arranged on the infrared heating units 11a, 11b and be movable together with the infrared heating units 11a, 11b.However, the shielding units 12 could also be attached to the housing 4 and arranged to be movable relative to the infrared heating units 11a, 11b.

[0030] The illustrated embodiment with two infrared heating units 11a, 11b is, of course, only an example, and within the scope of the invention, more or fewer than two infrared heating units 11 could also be provided. For example, in the case of pressure vessels 3 with a relatively large diameter, it could be advantageous if more than two infrared heating units 11a, 11b are provided distributed around the circumference of the receiving area 2, e.g., three to eight infrared heating units 11.

[0031] For particularly efficient heating of the pressure vessel 3, it can also be advantageous if a surface of the pressure vessel 3 is coated, for example, with a suitable lacquer, such as radiator lacquer. The surface should have the highest possible absorption coefficient in the infrared range. The absorption coefficient also depends on the wavelength of the infrared radiation and is preferably 0.9 to 1, preferably 0.95 to 1 in the range in which the infrared radiation maximum lies. This can, for example, at least partially eliminate the disadvantage that metals only absorb IR radiation in the near-infrared range (NIR) in the range of approximately 800-1400 nm and primarily reflect longer wavelengths. Alternatively or additionally, a lamp of the infrared heating units 11 itself could also be adapted, for example by using quartz-tungsten lamps that emit in the NIR range instead of the more common ceramic lamps.Furthermore, it would be conceivable that for the NIR range, in addition to at least one infrared heating unit 11, one or more suitable LED radiators are used.

[0032] Furthermore, a control unit 6 for controlling the filling device 1 is provided in the filling device 1, via which the filling process can be controlled. For this purpose, the control unit 6 is connected at least to the valve unit 5 and is designed to actuate the valve unit 5 in order to control a refrigerant quantity of the refrigerant K discharged from the pressure vessel 3 and supplied to the vehicle F. According to an advantageous embodiment, the control unit 6 is also connected to the heating device 9, in particular to the infrared heating units 11a, 11b, so that the heating device 9 can be activated or deactivated via the control unit 6 and, for example, the heating output of the infrared heating units 11a, 11b can also be controlled, preferably variably.

[0033] In the receiving area 2 of the filling device 1, a scale 13 for measuring the weight of the pressure vessel 3 is preferably also provided, which scale communicates in a suitable manner with the control unit 6. This allows a predetermined filling quantity to be specified to the air conditioning system of the vehicle F during a filling process by the control unit 6 controlling the valve unit 5 depending on a measured value m of the scale. For this purpose, for example, the recorded weight m of the pressure vessel 3 before the start of the filling process can be used as the initial weight m0, and a desired filling quantity in the form of a filling weight mF could be specified to the control unit 6. The control unit 6 can then keep the valve unit 5 open until the recorded weight m of the pressure vessel 3 corresponds to the initial weight m0 minus the filling weight mF.Alternatively or in addition to the scale 13, another form of measuring the fill quantity, in particular the fill weight, could also be used. For example, a suitable flow measuring device (not shown) could be provided in the filling device 1, for example in the area of ​​the valve unit 5, which detects a flow rate (volume flow or mass flow). The control unit 6 could control the valve unit 5 based on the detected flow rate in order to adjust the supplied fill quantity.

[0034] Furthermore, at least one pressure sensor 14 for detecting a pressure p of the refrigerant K and / or at least one temperature sensor 15 for detecting a temperature T of the refrigerant K and / or of the pressure vessel 3 and / or of the heating device 9 can be provided in the filling device 1. The pressure sensor 14 can, for example, be arranged between the outlet 3a of the pressure vessel 3 and the valve unit 5 and can communicate in a suitable manner with the control unit 6. The temperature sensor 15 can, for example, be designed as an infrared sensor to measure a surface temperature of the pressure vessel 3 and can also communicate in a suitable manner with the control unit 6. Of course, multiple temperature sensors 15 or pressure sensors 14 can also be provided, and other types of sensors would also be conceivable.

[0035] The control unit 6 can use the recorded sensor values ​​p, T to control or regulate the heating device 9 and, if applicable, also the valve unit 5. For this purpose, a suitable controller, e.g., a PI or PID controller, can also be integrated into the control unit 6. The controller can, for example, determine a manipulated variable S1 for controlling the heating device 9 and, if applicable, a manipulated variable S2 for controlling the valve unit 5 from a predetermined target value, e.g., a target temperature or a target pressure, and from the recorded sensor values ​​p, T. The control unit 6 can control the heating device 9 and, if applicable, the valve unit 5 with the manipulated variables S1, S2 in order to regulate the predetermined target values. The heating device 9 can, for example, also be controlled cyclically (on / off). For example, a maximum temperature can also be specified, and the control unit 6 can control the heating device 9 accordingly so that the maximum temperature is not exceeded.

[0036] Advantageously, the filling device 1 can also be provided with a user interface 16 connected to the control unit 6, via which control parameters of the filling process can be set. Via the user interface 16, a user can, for example, set a specific filling quantity or filling duration, which is then automatically fed to the vehicle F. The user interface 16 can also have an operating unit, which can include, for example, operating buttons, slide controls, or a touchscreen. However, the user interface 16 could also be designed without an operating unit and, for example, be configured merely to connect to an external computer. The filling process could then be controlled via the external computer.

[0037] A filling device 1 is generally used in workshops for filling several vehicles F that may be located at different locations. It can therefore be advantageous if the filling device 1 is designed as a mobile filling device. For this purpose, wheels can be arranged on an underside of the filling device 1 to enable the filling device 1 to be moved manually. For energy-autonomous operation of the filling device 1, a suitable energy storage device (not shown), for example an electric battery, could also be provided in the filling device 1. This would allow one or more filling processes to be carried out without an external power supply.

Claims

1. A filling device (1) for carrying out a filling process an air conditioning system of a vehicle (F) with a refrigerant (K), wherein in the filling device (1) there are provided a receiving region (2) for receiving a pressure container (3) filled with a refrigerant (K), a valve unit (5) being connected to an outlet (3a) of the pressure container (3) for controlling a quantity of the refrigerant being supplied to the vehicle (F), and a heating device (9) for heating the pressure container (3), characterized in that the heating device (9) has at least one infrared heating unit (11) to heat the pressure container (3) without any contact.

2. The filling device (1) according to claim 1, characterized in that a control unit (6) for controlling the filling process is provided in the filling device (1) and / or in that a scale (13) for measuring a weight of the pressure container (3) is provided in the receiving region (2).

3. The filling device (1) according to any one of claims 1 to 2, characterized in that at least one pressure sensor (14) for detecting a pressure (p) of the refrigerant (K) is provided in the filling device (1), and / or in that at least one temperature sensor (15) for detecting a temperature (T) of the pressure container (3) and / or of the heating device (9) and / or of the refrigerant (K) is provided in the filling device (1).

4. The filling device (1) according to any one of claims 1 to 3, characterized in that a plurality of infrared heating units (11a, 11b) is provided in the filling device (1), which are preferably arranged distributed around a circumference of the receiving region (2) and / or in that a shielding unit (12) is provided in the filling device (1) on a side of at least one infrared heating unit (11a, 11b) facing away from the receiving region (2), the shielding unit (12) preferably surrounding the infrared heating unit (11a, 11b) at least halfway in the circumferential direction.

5. The filling device (1) according to any one of claims 1 to 4, characterized in that at least one infrared heating unit (11a, 11b) is of elongated shape and is arranged in the filling device (1) in such a way that its longitudinal axis runs in parallel to a vertical axis of a pressure container (3) arranged upright in the receiving region (2).

6. The filling device (1) according to any one of claims 2 to 5, characterized in that a user interface (16) connected to the control unit (6) is provided on the filling device (1), via which user interface control parameters of the filling process can be set, in particular a quantity of the refrigerant being supplied to the air conditioning system and / or a filling duration.

7. The filling device (1) according to any one of claims 1 to 6, characterized in that the filling device (1) is designed as a mobile filling device (1), wherein wheels are arranged on an underside of the filling device (1) and / or wherein an energy storage is preferably provided in the filling device (1) to supply energy to the filling device (1) for carrying out at least one filling process.

8. The filling device (1) according to any one of claims 1 to 7, characterized in that at least one infrared heating unit (11a, 11b) is arranged being translationally and / or rotationally movable relative to the receiving region (2) and / or in that the receiving region (2) is designed to receive pressure containers (3) having a cylindrical bottle body with a bottle diameter of 15 cm to 40 cm.

9. A method for carrying out a filling process of an air conditioning system of a vehicle (F) with a refrigerant (K), wherein the refrigerant (K) is supplied to the vehicle (F) from a pressure container (3), wherein a supplied quantity of the refrigerant is controlled via a valve unit (5) connected to an outlet (3a) of the pressure container (3), and wherein the pressure container (3) is heated to increase a pressure (p) in the pressure container (3), characterized in that the pressure container (3) is heated by at least one infrared heating unit (11) without any contact.

10. The method according to claim 9, characterized in that carbon dioxide is used as refrigerant (K).

11. The method according to claim 9 or 10, characterized in that the filling process is controlled by a control unit (6) and / or in that a weight (m) of the pressure container (3) is measured during the filling process and in that the supplied quantity of the refrigerant is controlled on the basis of the measured weight (m).

12. The method according to any one of claims 9 to 10, characterized in that a pressure (p) of the refrigerant is detected and / or in that a temperature in the region of the pressure container (3) and / or in the region of the at least one infrared heating unit (11) and / or of the refrigerant (K) is detected, and in that the at least one infrared heating unit (11) and / or the valve unit (5) are controlled depending on the detected pressure (p) and / or the detected temperature (T).

13. The method according to any one of claims 9 to 12, characterized in that the pressure container (3) is heated by a plurality of infrared heating units (11a, 11b), which are preferably arranged distributed around a circumference of the pressure container (3), and / or in that a side of at least one infrared heating unit (11a, 11b) facing away from the pressure container (3) is shielded by a shielding unit (12), wherein the shielding unit (12) preferably surrounds the infrared heating unit (11a, 11b) at least halfway in the circumferential direction.

14. The method according to any one of claims 11 to 13, characterized in that at least one control parameter of the filling process is set via a user interface (16) connected to the control unit (6), preferably the supplied quantity of the refrigerant and / or a filling duration of the filling process.

15. The method according to any one of claims 9 to 14, characterized in that a distance (X) and / or an angle (ϕ) between at least one infrared heating unit (11a, 11b) and the pressure container (3) are changed.