Method and device for providing zeotropic refrigerants

Abstract

The disclosure relates to a method and a device for providing zeotropic refrigerants in which the refrigerant is formed from a refrigerant blend of at least two components, the components being added to a container in the ratio of their respective mass fractions to the refrigerant, and the refrigerant blend being formed in the container, wherein the temperature and/or the pressure in the container is set by means of a control device such that the refrigerant is present exclusively in the gas phase or exclusively in the liquid phase.

Claims

1. A method for providing zeotropic refrigerants in which a refrigerant is formed from a refrigerant blend of at least two components, the components being added to a container in the ratio of their respective mass fractions to the refrigerant, and the refrigerant blend being formed in the container, wherein the temperature in the container is set by a control device such that the refrigerant is present exclusively in a gas phase, wherein the temperature of the completely gaseous refrigerant is controlled by a temperature control of the control device and wherein the concentration of the components remains constant during removal of refrigerant from the container without further components having to be fed to the container.

2. The method according to claim 1, wherein a pressure of the completely gaseous refrigerant is controlled by a pressure control of the control device.

3. The method according to claim 1, wherein the refrigerant has a temperature glide of ≥10 K.

4. The method according to claim 1, wherein the refrigerant has a relative CO.sub.2 equivalent, over 20 years, of <2500.

5. The method according to claim 1, wherein the refrigerant is non-combustible.

6. The method according to claim 1, wherein the refrigerant is designed to be used for a temperature within a temperature range of −60° C. to +180° C.

7. The method according to claim 1, wherein the refrigerant is formed from a mass fraction of carbon dioxide (CO.sub.2) and a mass fraction of at least one further component.

8. The method of claim 1, wherein the control device is further configured to set a pressure in the container.

9. A device for providing zeotropic refrigerants, a refrigerant consisting of a refrigerant blend of at least two components, the device comprising at least two dosing valves and a container to which the components are added via the dosing valves in the ratio of their respective mass fractions to the refrigerant in order to form the refrigerant blend, wherein the device has a control device configured to set the temperature in the container such that the refrigerant is present exclusively in a gas phase, wherein the temperature of the completely gaseous refrigerant is controlled by a temperature control of the control device and wherein the concentration of the components remains constant during removal of refrigerant from the container without further components having to be fed to the container.

10. The device according to claim 9, wherein the control device has a temperature control and/or a pressure control.

11. The device according to claim 10, wherein the pressure control has a flexible diaphragm which is situated in an interior of the container, wherein the diaphragm divides the interior into an accommodation space for accommodating the refrigerant and an equalisation space for accommodating an equalisation gas.

12. The device according to claim 11, wherein the equalisation space is filled with nitrogen (N.sub.2).

13. The device according to claim 10, wherein the pressure control has a pressure sensor for measuring a container inner pressure and a pressure equalisation valve connected to the container.

14. The device according to claim 10, wherein the temperature control has a temperature sensor for measuring a container inner temperature and a temperature adjustment unit connected to the container and/or situated therein.

15. The device according claim 9, wherein the device has a pump for conveying components into the container.

16. The device according to claim 9, wherein the device has an outlet valve for removing the refrigerant from the container.

17. The device according to claim 9, wherein the device has a storage container with a feed line for each component, wherein a dosing valve of the at least two dosing valves and a mass flow sensor are connected in the feed line for feeding the components to the container.

18. The device according to claim 17, wherein the feed lines are connected to a static mixer or a jet mixer of the device.

19. A refrigeration machine having a device according to claim 9.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the figures:

(2) FIG. 1. shows a schematic diagram of a first embodiment of a device;

(3) FIG. 2 shows a schematic diagram of a second embodiment of a device.

DETAILED DESCRIPTION

(4) FIG. 1 shows a device 10 for providing zeotropic refrigerants, the device 10 having a container 11 for producing and storing a refrigerant blend (not visible here) of at least two components. The device 10 further comprises a feed line 12, 13, 38 for each of the components, having dosing valves 14, 15 and 37 and mass flow sensors 16, 17 and 39 arranged in the feed line 12, 13 and 38, respectively. The feed lines 12, 13 and 38 are each connected to a storage container (not shown) for storing the respective component. A mass fraction of the relevant component can be added to the refrigerant in the container 11 via the dosing valves 14, 15 and 37; the dosing valves 14, 15 and 37 can each be controlled by means of the mass flow sensors 16, 17 and 39, respectively.

(5) The feed lines 12, 13 and 38 are joined together in the feed line 18 such that the respective components are mixed in the feed line 18. The feed line 18 is directly connected to the container 11, and in the feed line 18 there is a pump 19 of the device 10, by means of which the refrigerant blend can be introduced into the container 11 under pressure. An outlet valve 20 for removing the refrigerant from the container 11 is also arranged on the container 11. For example, a further container or else a cooling circuit, which can then be filled with the refrigerant, can be connected to the outlet valve 20.

(6) The device 10 also has a control device 21, only part of which is shown here. The control device 21 has a pressure control means 22, which has a pressure sensor 23 for measuring a container inner pressure of the container 11 and a pressure equalisation valve 24 connected to the container 11. Refrigerant can be let out of the container 11 via the pressure equalisation valve 24 to reduce the container inner pressure. Furthermore, the pump 19 can be operated via the pressure sensor 23 when an increase in a container inner pressure or filling of the container 11 is necessary. The pressure control means 22 can have control members and means (not shown here) to operate the pressure equalisation valve 24 and the pump 19.

(7) In this embodiment of the device 10, the pressure control means 22 is designed such that there is in an interior 25 of the container 11 a flexible diaphragm 26 which divides the interior 25 into an accommodation space 27 for accommodating the refrigerant and an equalisation space 28 which is in this case filled with molecular nitrogen. A change in the volume of the accommodation space or a change in fill level caused by the removal of refrigerant from the accommodation space 27 is equalised by a corresponding change in the volume of the equalisation space 28 by means of the diaphragm 26, a pressure above the vapour pressure of the refrigerant always being set in the accommodation space 27 such that the refrigerant is completely present in liquid form, and therefore demixing of the refrigerant is prevented when refrigerant is removed from the container 11.

(8) FIG. 2 shows a further embodiment of a device 29 which, in contrast to the device of FIG. 1, has a container 30 with a pressure control means 31. The pressure control means 31 in this case likewise comprises a pressure sensor 23 and a pressure equalisation valve 24. A control device 32 of the device 29 has a temperature control means 33 in addition to the pressure control means 31. The temperature control means 33 comprises a temperature sensor 34 for measuring the container inner temperature or the temperature of a refrigerant situated in the interior 35 of the container 30 and a temperature adjustment unit 36 arranged in the interior 35. The refrigerant in the interior 35 can be cooled or heated using the temperature adjustment unit 36. The temperature adjustment unit 36 is controlled depending on a measurement value of the temperature sensor 34, so that the temperature of the refrigerant in the interior can always be set such that the refrigerant is present in the interior exclusively in the gas phase. Demixing of the refrigerant when the refrigerant is removed from the container 30 can thus be prevented.