WO2009052903A1

WO2009052903A1 - Expansion valve

Info

Publication number: WO2009052903A1
Application number: PCT/EP2008/007520
Authority: WO
Inventors: Michael Sonnekalb; Hartmut Gömpel; Stefan Saiz
Original assignee: Konvekta Ag
Priority date: 2007-10-24
Filing date: 2008-09-12
Publication date: 2009-04-30
Also published as: DE102007051118A1; DE102007051118B4

Abstract

A thermostatic expansion valve (1) for a refrigerating system, which is operated with the refrigerant CO2, or an air-conditioning system is described, said expansion valve having an actuating element (12) which is operated without auxiliary power and has a temperature sensor (15) which is filled with a filling material. The filling material is a mixture comprising at least the components carbon dioxide (CO2) and dinitrogen monoxide (N2O) or a hydrocarbon or water, or dinitrogen monoxide or a mixture comprising at least the components dinitrogen monoxide and a hydrocarbon or water.

Description

Konvekta AG

Am Nordbahnhof 5, 34613 Schwalmstadt, DE

expansion valve

The invention relates to a thermostatic expansion valve for an air conditioning or refrigeration system with the refrigerant CO ₂ .

Air conditioning or refrigeration systems according to the compressor principle have at least the

Components compressor, radiator, expansion valve and evaporator, which are connected in a circle, wherein the emerging from the condenser compressed and high pressure refrigerant - this may be supercritical gas or liquid - is expanded in the expansion valve, then completely evaporated in an evaporator whereby it draws the evaporation energy from a medium to be cooled and this cools, then is compressed in the compressor, wherein the high-pressure refrigerant is cooled in the subsequent cooler and is provided at the outlet of the cooler for a further cycle.

Conventional refrigerants, such as ammonia or fluorine hydrocarbons are increasingly being replaced by carbon dioxide (CO ₂ ), which has particular advantages because of the lower greenhouse effect. The refrigerant However, carbon dioxide requires the design of the air conditioning or refrigeration system for much higher operating pressures than before.

DE 198 32 479 A1 describes an expansion valve which is designed as a fixed throttle. The throttle opening is matched with respect to length and diameter of the system that in all operating conditions, the pressure in a high pressure section is limited to about 14 MPa.

In particular, air conditioners for highly variable operating conditions, such as are typical for vehicle air conditioning systems, however, require adjustable expansion valves.

In WO 2006/057093 A1, a pressure-controlled expansion valve without auxiliary power is provided for an air-conditioning system operated with the refrigerant carbon dioxide.

US Pat. No. 6,385,980 B1 provides a flow-controlled expansion valve with auxiliary energy, the control of the electrically controllable valve being effected by an electronic control unit.

Widely used have thermostatic expansion valves found whose actuators have a temperature sensor or are connected to such and are operated either with auxiliary power or without auxiliary power. The temperature sensor can be arranged on the high-pressure side of the refrigerant circuit at the outlet of the cooler or on the low-pressure side at the outlet of the

Evaporator. In the latter arrangement, the expansion valve is controlled by the so-called overheating of the refrigerant, which may for example be in the range of 5 to 15 K and indicates by what amount the temperature at Output of the evaporator exceeds the evaporation temperature of the refrigerant.

US 2005/0132731 A1 describes an air conditioning system with the refrigerant carbon dioxide with an expansion valve which is operated with auxiliary electric power and is provided by a control unit which is connected to a temperature sensor arranged at the outlet of the cooler.

EP 1 532 408 AO describes an air conditioning system for automobiles with the refrigerant carbon dioxide, wherein the expansion valve is operated with auxiliary electric power and the temperature sensor is arranged at the outlet of the cooler.

DE 10 2005 050 086 A1 describes a thermostatic expansion valve without auxiliary energy, wherein the temperature sensor may comprise the refrigerant or another substance as a filler. This document does not provide carbon dioxide as a refrigerant.

DE 10 2004 005 379 B3 describes a thermostatic expansion valve without auxiliary power, which has a temperature- or pressure-sensitive actuator, which is designed in particular as a membrane or bellows system. The bellows system may have a refrigerant, inert gas or Adsorberfüllung. This document does not provide carbon dioxide as a refrigerant.

The invention has for its object to provide an improved expansion valve, which is adjustable without auxiliary power.

This object is achieved with a thermostatic expansion valve for one operated with the refrigerant CO ₂ refrigeration system or air conditioning, the at least one compressor, a radiator, the thermostatic expansion valve and a Evaporator comprises, wherein the expansion valve has an auxiliary power operated and a valve element adjusting actuator with a temperature sensor filled with a filled dissolved, wherein it is provided that the filler is a mixture of at least the components carbon dioxide (CO2) and nitrous oxide (N ₂ O) or from at least the components carbon dioxide and a hydrocarbon or at least the components carbon dioxide and water, or that the filler is nitrous oxide, or that the filler is a mixture of at least the components dinitrogen monoxide and a hydrocarbon or at least the components dinitrogen monoxide and Water is.

Such a thermostatic expansion valve has the advantage, in particular for use in vehicle air conditioning systems, that on the one hand it requires no auxiliary power and, on the other hand, that it can be replaced by the proposed fillers of the

Temperature sensor is optimally adapted to different conditions of use. In particular, the proposed multicomponent systems give the person skilled in the art the possibility to influence the characteristic of the temperature sensor in a simple manner by exchanging a component or by changing the mixing ratio.

The proposed filler compositions are usable

- as a universal filling in which the filling quantity is so great that there is always a partial filling in the sensor; - As so-called MOP filling (Maximum Operating Pressure or engine

Overload Protection), in which the filling has evaporated when the temperature has reached the MOP point, and - As MOP filling with ballast, in which an additional adsorbent material is introduced into the temperature sensor, so that the control behavior is damped.

It may be provided that the hydrocarbon is a hydrocarbon from the group of alkanes, alkenes, alkynes, or alkanols. From the group of alkanes, ethane, propane, butane, isobutane and pentane may be preferred. Propene may be preferred from the group of alkenes. From the group of alkynes, ethyne and propyne may be preferred. From the group of alkanols methanol may be preferred. Hydrocarbons having up to five carbon atoms may preferably be provided, but hydrocarbons having up to ten carbon atoms are also conceivable.

Advantageous filler compositions emerge from claims 3 to 22. In these claims, the preferred proportions by mass of two mixture components are preferably given as and-or alternatives on the one hand for various filler mixtures and on the other hand, the mass fractions of the two components in the case of 2-components Mixture indicated. In alternative 1, the two specified mixture components are to be understood as main components, it being possible for further components to be contained as secondary components in the filler mixture. The

Secondary components may preferably have a mass fraction of at most 5 percent by weight of the filler mixture.

Further advantageous embodiments are obtained by special structural design of the expansion valve.

It can be provided that the actuator is designed as a membrane or bellows system, which by means of a capillary with the output of the Temperature sensor is connected.

It can further be provided that the travel of the valve element corresponds to the travel of the actuator. It can therefore be provided that the travel of the actuator is transmitted in a ratio of 1: 1 to the valve element, for example, by an actuator disposed on the adjusting pin is arranged in alignment with the valve element.

But it can also be provided that the travel of the valve element is smaller or larger than the travel of the actuator. For example, a

Be provided lever mechanism to increase the travel of the actuator in the ratio n: 1 or in the ratio 1: n to reduce, where n> 1.

It is also possible that the low pressure formed in the downstream of the valve element extending inner portion of the expansion valve is transmitted to the actuator. For example, when the actuator is terminated by a diaphragm, the low pressure of the expanded refrigerant formed after the expansion valve acts on the diaphragm when the space remote from the actuator is connected to the outlet portion of the expansion valve in front of the diaphragm.

It may further be provided that the filler of the temperature sensor forms a sensor internal pressure, which corresponds to the sum of the evaporation pressure of the refrigerant and a pressure caused by an adjustment when the temperature acting on the temperature sensor at the outlet of the evaporator equal to the desired superheat temperature of the refrigerant is. If, for example, the actuator is closed by a membrane, so acts on the actuator facing side of the membrane, the sensor internal pressure and on the side facing away from the actuator of the membrane, the evaporation pressure of the refrigerant and the pressure, which is caused by the adjusting device, which has, for example, a prestressed compression spring. The adjustment device is used to adjust the static overheating. If the sensor internal pressure predominates because the temperature at the temperature sensor exceeds the setpoint temperature, then the expansion valve opens, when the evaporation pressure and the pressure of the adjustment prevails, for example, because the temperature at the temperature sensor is below the target temperature, then closes the expansion valve. In the selected operating point, therefore, the forces acting on both sides of the membrane are in equilibrium. An advantage of this design is that the expansion valve in each case corrects the overheating of the evaporator or the associated low-pressure heat exchanger and thus adapts the injected amount of refrigerant to the current refrigeration demand. If, for example, a plurality of evaporators are provided in a larger air conditioning or refrigeration system, then an expansion valve can be provided for each evaporator, so that the overheating of each of the evaporators can be regulated separately. In a regulation of the high pressure, this would not be possible.

Further features, details and advantages of the invention will become apparent from the following description of embodiments of inventive expansion valves with reference to the drawings.

Show it

1 shows a section through an inventive expansion valve.

2 is a schematic representation of a refrigerant circuit in which an expansion valve according to the invention is arranged; 3 is a schematic representation of a refrigerant circuit in which two expansion valves according to the invention are arranged;

Fig. 4 shows the vapor pressure of carbon dioxide (CO ₂ ) and ethyne (C ₂ H ₂ ), as well as

Mixtures of CO ₂ and C ₂ H ₂ in different mixing ratios, as a function of temperature;

Fig. 5 shows the vapor pressure of carbon dioxide (CO ₂ ) and nitrous oxide (N ₂ O), and mixtures of CO ₂ and N ₂ O in different

Mixing ratios, as a function of temperature;

Fig. 6 shows the vapor pressure of carbon dioxide (CO ₂ ) and propane (C ₃ H ₈ ), as well as

Mixtures of CO ₂ and C ₃ H ₈ in different proportions, as a function of temperature.

Fig. 1 shows a section through a thermostatic expansion valve 1 according to the invention with a housing 10 having an inlet port 10e and an outlet nozzle 10a, which are arranged at a right angle to each other. The expansion valve 1 is thus constructed as an angle valve, wherein in the position of use of the inlet nozzle 1Oe points downward. All other position assignments are based on the position of use of the expansion valve. The inlet port 1Oe is connected in operational use with the high pressure side of a refrigerant circuit and the outlet port 10a with the low pressure side. The refrigerant circuit has at least one compressor, a cooler or high-pressure heat exchanger, the expansion valve 1 and an evaporator or low-pressure heat exchanger, as described in more detail below. For controlling the flow rate or for completely shutting off the refrigerant flowing from the inlet port 10e to the outlet port 10a, there is provided a cylindrical valve element 11 disposed between the inlet port 10e and the outlet port 10a, the downstream end portion of which is formed as a poppet 11k. The poppet 11k cooperates with a housing-fixed valve seat 11s, which is designed as a hollow cone. When the poppet 11 k comes into abutment in the valve seat 11 s, the expansion valve 1 is closed.

To set the expansion valve 1, an actuator 12 is provided, which is formed as a pressure-tight chamber, which is completed by a arranged on the underside of the chamber membrane 12m. On the underside of the diaphragm 12m, an adjusting pin 12s is arranged, which is pressed by a trained as a compression spring adjusting spring 13f an adjusting device 13 with its upper end portion against the diaphragm 12m. The adjusting spring 13f rests with its lower end face on the upper side of a setting ring 13r. The adjusting ring 13r is guided on a hollow cylindrical portion in the interior of the housing 10, which further passes through the adjusting spring 13f. The conical outer periphery of the adjusting ring 13 r abuts against the end face of an adjusting screw 13 s, which is screwed into a threaded hole of the housing 10. By screwing the adjusting screw 13s, the adjusting ring 13r is raised and the adjusting spring 13f is biased. Due to the fact that the adjusting screw 13s acts on a conical jacket, a sensitive adjustment and a force reduction is achieved.

The actuator 12 is connected via a capillary tube 14 with a temperature sensor 15. The temperature sensor 15 is arranged at the outlet of the evaporator or low-pressure heat exchanger and determines the so-called overheating of the vaporized refrigerant. A filler contained in the temperature sensor 15 generates depending on the temperature of the temperature sensor 15, a sensor internal pressure, which is transmitted via the capillary tube 14 to the diaphragm 12m of the actuator 12. Against the sensor internal pressure, which wants to open the expansion valve 1, the refrigerant pressure acts on the opposite side of the diaphragm 12m and a set pressure formed by the spring force of the adjusting spring 13f which, as described above, is adjustable by means of the adjusting screw 13s. As the refrigerant pressure is in the embodiment shown in FIG. 1, the evaporation pressure of the refrigerant at the outlet of the expansion valve 1 at. However, it can also be provided that the refrigerant pressure in the vicinity of the temperature sensor 15 is guided via a further capillary tube to the expansion valve 1. Such valves are referred to as a valve with external pressure compensation.

With increasing temperature at the temperature sensor 15, the sensor internal pressure increases and opens the expansion valve 1. It is injected more evaporating - and cooling - refrigerant in the evaporator. This counteracts the overheating of the refrigerant. When the temperature at the temperature sensor 15 falls, the internal pressure of the sensor decreases correspondingly and closes the expansion valve 1. If the refrigerant pressure drops sharply, the refrigerant overheats at a constant evaporator outlet temperature. With decreasing refrigerant pressure, the valve opens and acts according to the above. Overheating versions. Conversely, the effect is with increasing refrigerant pressure.

Fig. 2 shows a refrigeration or air conditioning system 2 with a thermostatic expansion valve 23 according to the invention with a temperature sensor 23t. The refrigeration or air conditioning system 2 has a compressor 21, which may be a reciprocating compressor, a cooler or high-pressure heat exchanger 22, the Expansion valve 23, an evaporator or low-pressure heat exchanger 24 and connecting lines 25 on. The refrigerant, which is CO ₂ in the embodiment shown in FIG. 2, flows in a closed circuit from the compressor 21 via the cooler 22, which can operate as a gas cooler or as a condenser, the expansion valve 23 and the evaporator 24 again back to the compressor 21. The expansion valve 23 controls overheating of the vaporized refrigerant at a point between the exit of the vaporized refrigerant from the evaporator 24 and the entry of the vaporized refrigerant into the compressor 21 to which the temperature sensor 23t is mounted.

Fig. 3 shows a refrigeration or air conditioning system 3 with two thermostatic expansion valves 33a and 33b according to the invention. The refrigeration or air conditioning system 3 has a compressor 31, which may be, for example, a reciprocating compressor, a cooler or high-pressure heat exchanger 32, and two parallel sections with the expansion valves 33a and 33b and evaporators or low-pressure heat exchangers 34a and 34b and connecting lines 35 and 35p. The refrigerant, which is CO ₂ in the embodiment shown in FIG. 3, flows from the compressor 31 via the radiator 32 and then into the parallel communication lines 35 p to the two expansion valves 33 a and 33 b, and from there via the respective ones

Low-pressure heat exchangers 34a and 34b back to the compressor 31. The expansion valves 33a and 33b have temperature sensors 33at and 33bt, which are mounted between the exit of the vapor refrigerant from the evaporators 34a and 34b and the inlet of the vapor refrigerant in the compressor 31 and regulate the overheating of the vaporous refrigerant at the measuring points. 4 to 6 now show pressure-temperature diagrams of the temperature sensor in Fig. 1 to 3 for selected fillers, in each of which on the X-axis, the sensor temperature in the range of -50 ⁰ C to +30 ⁰ C is removed and in which the sensor internal pressure is plotted in the range of 0 bar to 80 bar on the Y axis.

Fig. 4 shows vapor pressure curves for a filler formed from a mixture of carbon dioxide and ethyne. The components of the mixture are given as weight percentages by weight.

The upper vapor pressure curve shows the vapor pressure curve for a mixture of 100 percent by weight carbon dioxide and 0 percent by weight ethyne, the lower vapor pressure curve shows the vapor pressure curve for a mixture of 0 percent by weight carbon dioxide and 100 percent by weight ethyne. The space between the two vapor pressure curves indicates the vapor pressure of mixtures of x percent by weight carbon monoxide and y percent by weight ethyne, with no intermediate values being entered for the sake of clarity. Between the lower and upper vapor pressure curve can be linearly interpolated with good approximation.

The admixture of a component such as ethyne to the filler carbon dioxide improves the control behavior of the actuator shown in Fig. 1 and further allows optimal adaptation to the operating point of the thermostatic expansion valve 1 and thus a good adaptation to the desired overheating of the refrigerant.

Fig. 5 now shows vapor pressure curves for a filler formed from a mixture of carbon dioxide and dinitrogen monoxide. The upper vapor pressure curve shows the vapor pressure curve for a mixture of 100 weight percent carbon dioxide and 0 weight percent nitrous oxide, the lower vapor pressure curve shows the vapor pressure curve for a mixture of 0 weight percent carbon dioxide and 100 weight percent nitrous oxide. The space between the two vapor pressure curves indicates the vapor pressure of mixtures of x percent by weight carbon monoxide and y percent by weight nitrous oxide, with no intermediate values being entered for the sake of clarity. Between the lower and upper vapor pressure curve can be linearly interpolated with good approximation. In comparison with FIG. 4, it can be seen that the vapor pressure curves for carbon dioxide and dinitrogen monoxide are close to one another, so that filler mixtures based on dinitrogen monoxide can also be provided.

6 shows, analogously to FIGS. 4 and 5, vapor pressure curves for a filler mixture of carbon dioxide and propane.

The upper vapor pressure curve shows the vapor pressure curve for a mixture of 100 weight percent carbon dioxide and 0 weight percent propane, the lower vapor pressure curve shows the vapor pressure curve for a mixture of 0 weight percent carbon dioxide and 100 weight percent propane. The space between the two vapor pressure curves gives the vapor pressure of mixtures of x percent by weight carbon monoxide and y percent by weight propane. The admixture of propane to carbon dioxide, a particularly large working range of the filler can be adjusted.

It has been found that based on carbon dioxide or nitrous oxide and hydrocarbons or water, filler mixtures can be provided which cover a wide range of applications cover. The following rules can be used to select suitable filler mixtures.

It is advantageous to choose the mixture so that at a low evaporation temperature of eg -25 ⁰ C overheating of eg 5K is achieved. This overheating should not be too great, so that the compression end temperature does not become too high when compressed above the critical pressure. On the other hand, it should be avoided that unevaporated portions of the refrigerant are sucked from the compressor and lead there to liquid blows.

It is also advantageous to choose the mixture so that at a high evaporation temperature of, for example, 10 ⁰ C, an overheating of eg 15 K is not exceeded.

Mixtures, as shown in Table 1 and Table 2, have proven to be particularly advantageous.

Table 1: Filler mixtures of carbon dioxide (CO ₂ ) and another component

Table 2: Filler mixtures of nitrous oxide (N ₂ O) and another component

The normal boiling points of the components are given in Table 3 below.

Table 3: Normal boiling points of the components given in Tables 1 and 2

LIST OF REFERENCE NUMBERS

1 thermostatic expansion valve

2 refrigeration or air conditioning

3 refrigeration or air conditioning

10 housing

10a outlet

1Oe inlet nozzle

11 valve element

11f compression spring

11k valve cone

11s valve seat

12 actuator

12m membrane

12s setting pin

13 setting device

13f adjusting spring

13r adjustment ring

13s adjusting screw

14 capillary tube

15 temperature sensor

20 refrigeration cycle

21 compressors

22 radiator or high pressure heat exchanger

23 expansion valve

23t temperature sensor

24 evaporator or low pressure heat exchanger 25 connection line

30 refrigeration cycle

31 compressors

32 coolers or high pressure heat exchanger 33a expansion valve

33at temperature sensor

33b expansion valve

33bt temperature sensor

34a evaporator or low-pressure heat exchanger 34b evaporator or low-pressure heat exchanger

35 connecting line

35p parallel connection line

Claims

Konvekta AGAm Nordbahnhof 5, 34613 Schwalmstadt, DEPatentansprüche

A thermostatic expansion valve (1) for a refrigeration system or air conditioning system operating with the refrigerant CO ₂ , which comprises at least one compressor, a cooler, the thermostatic expansion valve (1) and an evaporator, wherein the expansion valve is an auxiliary-operated and a valve element (11 ) adjusting actuator (12) having a temperature sensor (15) filled with a filler, characterized in that a) that the filler is a mixture of at least the components

Is carbon dioxide (CO ₂ ) and nitrous oxide (N ₂ O), or b) that the filler is a mixture of at least the components carbon dioxide (CO ₂ ) and a hydrocarbon, or c) that the filler is a mixture of at least the components

Carbon dioxide (CO ₂ ) and water, or d) the filler is a mixture of at least the components carbon dioxide (CO ₂ ) and an organic or inorganic substance with a normal boiling point between -90 ⁰ C and + 200 ⁰ C, or e) that the filler is nitrous oxide, or f) that the filler is a mixture of at least the components nitrous oxide and a hydrocarbon, or g) that the filler is a mixture of at least the components dinitrogen monoxide and water, or h) that the filler is a mixture of at least the components

Nitrous oxide and an organic or inorganic substance having a normal boiling point between -90 ⁰ C and + 200 ° C.

2. Thermostatic expansion valve according to claim 1, characterized in that it is the hydrocarbon is a hydrocarbon from the group of alkanes, alkenes, alkynes, or alkanols.

3. Thermostatic expansion valve according to one of the preceding claims, dad urch geken Nzeich net, that it is the inorganic substance is ammonia.

4. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler comprises at least the components carbon dioxide and ethane (C ₂ H ₆ ) having a mass ratio of 57 to 43 to 19 to 81, and / or that the filler of carbon dioxide and Ethane is, it being preferably provided that the ethane is a mass fraction between

43 and 81 percent by weight of the filler.

5. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler comprises at least the components carbon dioxide and propane (C ₃ H ₈ ) with a mass ratio of 84 to 16 to 64 to 36, and / or that the filler of carbon dioxide and Propane is provided, it is preferably provided that the propane has a mass fraction of between 16 and 36 weight percent of the filler.

6. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components carbon dioxide and butane

(C ₄ Hi ₀ ) having a mass fraction ratio of 82 to 18 to 62 to 38, and / or that the filler consists of carbon dioxide and butane, wherein it is preferably provided that the butane is a mass fraction between

18 and 38 weight percent of the filler.

7. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components carbon dioxide and

Isobutane (C ₄ H ₁₀ ) having a mass fraction ratio of 82 to 18 to 62 to 38, and / or that the filler consists of carbon dioxide and isobutane, wherein it is preferably provided that the isobutane is a mass fraction between

18 and 38 weight percent of the filler.

8. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler comprises at least the components carbon dioxide and pentane (C ₅ Hi ₂ ) with a mass ratio of 79 to 21 to 58 to 42, and / or that the filler of carbon dioxide and Pentane is, it is preferably provided that the pentane has a mass fraction of between 21 and 42 percent by weight of the filler.

9. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components carbon dioxide and

Propene (C ₃ H ₆ ) having a mass ratio of 84 to 16 to 64 to 36, and / or that the filler consists of carbon dioxide and propene, wherein it is preferably provided that the propene has a mass fraction between

16 and 36 weight percent of the filler.

10. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components carbon dioxide and ethyne

(C ₂ H ₂ ) having a mass fraction ratio of 51 to 49 to 0.1 to 99.9, and / or that the filler consists of carbon dioxide and ethyne, wherein it is preferably provided that the ethyne has a mass fraction of at least 49 percent by weight of Has filler.

11. A thermostatic expansion valve according to claim 1 or 2, characterized in that the filler comprises at least the components carbon dioxide and propyne (C ₃ H ₄ ) with a mass ratio of 86 to 14 to 69 to 31, and / or that the filler of carbon dioxide and Propin is provided, it is preferably provided that the propyne has a mass fraction between 14 and 31 weight percent of the filler.

12. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler comprises at least the components carbon dioxide and methanol (CH ₄ O) having a mass ratio of 89 to 11 to 76 to 24, and / or that the filler of carbon dioxide and methanol it is preferably provided that the methanol has a mass fraction between 11 and 24 weight percent of the filler.

13. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components carbon dioxide and

Water (H ₂ O) having a mass ratio of 94 to 6 to 85 to 15, and / or that the filler consists of carbon dioxide and water, wherein it is preferably provided that the water is a mass fraction between

6 and 15 weight percent of the filler.

14. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler comprises at least the components dinitrogen monoxide and ethane with a mass ratio of 77 to 23 to 24 to 76, and / or that the filler consists of nitrous oxide and ethane, preferably provided in that the ethane has a mass fraction between 23 and 76% by weight of the filler.

15. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components dinitrogen monoxide and

Propane having a mass ratio of 94 to 6 to 74 to 26, and / or that the filler consists of nitrous oxide and propane, wherein it is preferably provided that the propane has a mass fraction between

6 and 26 weight percent of the filler.

16. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components dinitrogen monoxide and

Butane with a mass ratio of 91 to 9 to 73 to 27, and / or that the filler consists of nitrous oxide and butane, wherein it is preferably provided that the butane has a mass fraction of between 9 and 27 weight percent of the filler.

17. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler comprises at least the components dinitrogen monoxide and isobutane with a mass ratio of 91: 9 to 73 to 27, and / or that the filler consists of nitrous oxide and isobutane, preferably provided is that the isobutane has a mass fraction between 9 and 27 percent by weight of the filler.

18. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components dinitrogen monoxide and

Pentane having a mass ratio of 89 to 11 to 69 to 31, and / or that the filler consists of nitrous oxide and pentane, wherein it is preferably provided that the pentane has a mass fraction between

11 and 31 weight percent of the filler.

19. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components dinitrogen monoxide and

Propene having a mass ratio of 92 to 8 to 71 to 29, and / or that the filler consists of nitrous oxide and propene, wherein it is preferably provided that the propene mass fraction between

8 and 29 weight percent of the filler.

20. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler has at least the components dinitrogen monoxide and ethyne with a mass fraction ratio of 75 to 25 to 0.1 to 99.9, and / or that the filler consists of nitrous oxide and ethyne , wherein it is preferably provided that the ethyne has a mass fraction of at least 25 percent by weight of the filler.

21. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components dinitrogen monoxide and

Propin having a mass ratio of 93 to 7 to 78 to 22, and / or that the filler consists of nitrous oxide and propyne, wherein it is preferably provided that the propyne has a mass fraction of between 7 and 22 percent by weight of the filler.

22. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler at least the components dinitrogen monoxide and

Methanol having a mass ratio of 99.9 to 0.1 to 83 to 17, and / or that the filler consists of nitrous oxide and methanol, wherein it is preferably provided that the methanol has a proportion by mass of not more than 17 percent by weight of the filler.

23. Thermostatic expansion valve according to claim 1 or 2, characterized in that the filler has at least the components dinitrogen monoxide and water with a mass ratio of 99.9 to 0.1 to 90 to 10, and / or that the filler consists of nitrous oxide and water , It is preferably provided that the water has a mass fraction of not more than 10 percent by weight of the filler.

24. Thermostatic expansion valve according to claim 1 or 3, characterized in that the filler has at least the components carbon dioxide (CO ₂ ) and ammonia with a mass ratio of 93.1 to 6.9 to 82.4 to 17.6, and / or the filler consists of carbon dioxide (CO ₂ ) and ammonia, wherein it is preferably provided that the ammonia has a mass fraction of 6 to 18% by weight of the filler.

25. Thermostatic expansion valve according to claim 1 or 3, characterized in that the filler has at least the component dinitrogen monoxide and ammonia with a mass ratio of 97.2 to 2.8 to 88.6 to 11.4, and / or that the filler from Nitrous oxide and ammonia, wherein it is preferably provided that the ammonia is a mass fraction of

2 to 12% by weight of the filler.

26. Thermostatic expansion valve according to one of the preceding claims, characterized in that the actuator (12) is designed as a membrane or bellows system, which is connected by means of a capillary (14) to the output of the temperature sensor (15).

27. Thermal expansion valve according to one of the preceding claims, characterized in that the travel of the valve element (11) corresponds to the travel of the actuator (12).

28. Thermostatic expansion valve according to one of claims 1 to 23, characterized in that the travel of the valve element (11) is smaller or larger than the travel of the actuator (12).

29. Thermostatic expansion valve according to one of the preceding claims, characterized in that in the downstream of the valve element (11) extending inner portion of the expansion valve (1) formed low pressure is transmitted to the actuator (12).

30. Refrigeration system or air conditioning with the refrigerant CO ₂ with a

Refrigerant circuit comprising at least a compressor, a radiator, a thermostatic expansion valve and an evaporator, wherein the expansion valve (1) is designed according to one of the preceding claims 1 to 26, characterized in that the filling means of the temperature sensor (15) forms a sensor internal pressure, which corresponds to the sum of the evaporation pressure of the refrigerant and a pressure caused by an adjusting device (13) when the temperature acting on the temperature sensor (15) at the outlet of the evaporator is equal to the desired super-heating temperature of the refrigerant.