WO2018177465A1 - Mixture for a refrigerant circuit of a compression unit and the use thereof - Google Patents

Mixture for a refrigerant circuit of a compression unit and the use thereof Download PDF

Info

Publication number
WO2018177465A1
WO2018177465A1 PCT/DE2018/100238 DE2018100238W WO2018177465A1 WO 2018177465 A1 WO2018177465 A1 WO 2018177465A1 DE 2018100238 W DE2018100238 W DE 2018100238W WO 2018177465 A1 WO2018177465 A1 WO 2018177465A1
Authority
WO
WIPO (PCT)
Prior art keywords
refrigerant
mixture
lubricant
mass
carbon dioxide
Prior art date
Application number
PCT/DE2018/100238
Other languages
German (de)
French (fr)
Inventor
Joachim Germanus
Original Assignee
Institut Für Luft- Und Kältetechnik Gemeinnützige Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institut Für Luft- Und Kältetechnik Gemeinnützige Gmbh filed Critical Institut Für Luft- Und Kältetechnik Gemeinnützige Gmbh
Publication of WO2018177465A1 publication Critical patent/WO2018177465A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
    • C09K5/02—Materials undergoing a change of physical state when used
    • C09K5/04—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa
    • C09K5/041—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa for compression-type refrigeration systems
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M171/00—Lubricating compositions characterised by purely physical criteria, e.g. containing as base-material, thickener or additive, ingredients which are characterised exclusively by their numerically specified physical properties, i.e. containing ingredients which are physically well-defined but for which the chemical nature is either unspecified or only very vaguely indicated
    • C10M171/008—Lubricant compositions compatible with refrigerants
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
    • C09K2205/10—Components
    • C09K2205/106—Carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2205/00—Aspects relating to compounds used in compression type refrigeration systems
    • C09K2205/40—Replacement mixtures
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
    • C10M2213/04—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions obtained from monomers containing carbon, hydrogen, halogen and oxygen
    • C10M2213/043—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions obtained from monomers containing carbon, hydrogen, halogen and oxygen used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
    • C10M2213/06—Perfluoro polymers
    • C10M2213/0606—Perfluoro polymers used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
    • C10N2020/09—Characteristics associated with water
    • C10N2020/097—Refrigerants
    • C10N2020/106—Containing Carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/10—Inhibition of oxidation, e.g. anti-oxidants
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/70—Soluble oils
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/30—Refrigerators lubricants or compressors lubricants

Definitions

  • the invention relates to a mixture for a refrigerant circuit in compression refrigeration refrigeration systems, whose main component is a natural refrigerant.
  • the substance mixture can be used as substitute for the refrigerant trifluoromethane (R23) at evaporation temperatures below -60 ° C.
  • Two-stage cascade refrigeration systems can be used for refrigeration in the temperature range between -55 ° C and -90 ° C; in the lower stage, which is also referred to as low-temperature, with the refrigerants trifluoromethane CHF3 (R23), the azeotropic mixture CHF3 / C2F6 (R508) or Ethan C2H6 (R170).
  • refrigerants trifluoromethane CHF3 (R23), the azeotropic mixture CHF3 / C2F6 (R508) or Ethan C2H6 (R170).
  • An important aspect of refrigerants, apart from their toxicity and combustibility, is their global warming potential, which is described by the GWP value (English: Global Warming Potential or Greenhouse Warming Potential).
  • a CO2-based refrigerant for compression refrigeration systems is known, which can also be used at temperatures up to -70 ° C. This is achieved by adding 30% by mass to 15% by mass of nitric oxide monoxide. Apart from this small addition to CO2, nitrous oxide, popularly known as “nitrous oxide”, is not used as a refrigerant for compression refrigeration systems.
  • Nitrous oxide can be used at evaporation temperatures of -90 ° C. At atmospheric pressure, however, there is the danger of explosive decomposition above a temperature of about 565 ° C. By different factors (eg increased pressure, catalytic factors), the decomposition temperature of nitrous oxide can even be significantly reduced. In the past, there were already serious accidents with nitrous oxide.
  • the upper limit of the compressor end temperature in a compression refrigeration system is 150 ° C and thus in a non-critical temperature range for nitrous oxide.
  • the temperature may rise locally to over 600 ° C, leaving a real danger of a nitrous oxide explosion in a compression refrigeration system operated as a refrigerant with dinitrogen monoxide. For this reason, there are reasonable safety concerns about the use of pure N2O in refrigeration systems.
  • the invention has for its object to provide a cost-effective, incombustible, especially explosion-proof mixture for compression refrigeration systems, which includes a natural refrigerant as a replacement for R23 (trifluoromethane), by means of which temperatures below -70 ° C should be achievable in the evaporator, wherein the refrigerant Moreover, compared with R23, it has a low global warming potential, good energy efficiency and a low process pressure ratio.
  • the mixture of substances according to the invention for a refrigerant circuit of a compression refrigeration system consists of a refrigerant and an inert lubricant.
  • the refrigerant in turn consists of nitrous oxide and carbon dioxide.
  • the proportion of carbon dioxide in the refrigerant is in the range between 18% by mass and 30% by mass.
  • the remaining proportion of the refrigerant, ie 70 to 82% by mass, is dinitrogen monoxide.
  • the two components carbon dioxide and dinitrogen monoxide are completely miscible in the liquid state.
  • the carbon dioxide concentration is to be selected as low as possible.
  • the proportion of CO 2 is at least 17% by mass. Since the addition of a safety margin of one mass% makes sense, the proportion of CO2 is preferably at least 18% by mass. However, in order to be able to make the best possible use of the advantages of nitrous oxide as a refrigerant, a C02 proportion of not more than 20% by mass is preferred, ideally providing a carbon dioxide fraction of 18% by mass.
  • Lubricant added to the compressor lubrication is required to the inventive mixture in a compression refrigeration system with Compressors to be able to use, wherein the lubricant added to the acting as a strong Oxidungsm title dinitrogen monoxide resistant to oxidation, that is inert, is. Preference is given to a partial solubility of the lubricant in the liquid refrigerant and a partial solubility of the refrigerant in the liquid
  • the advantage of this substance mixture is the comparatively low global warming potential of the refrigerant, with a GWP of only about 200 compared to R23 with a GWP value of 14800. Due to its main component nitrous oxide, the evaporation temperatures of almost -90 ° C are possible with the refrigerant, so it can be used in modified compression refrigeration systems to generate such low temperatures. Nitrous oxide and carbon dioxide are both naturally occurring compounds which have been classified as nontoxic in intensive toxicological investigations and are also available at low cost, as a result of which the refrigerant according to the invention is harmless to human health both in low doses and in sufficient quantities for use in compression refrigeration systems for temperature ranges below. 50 ° C can be produced. Thus, it can be used as a cost-effective replacement for the previously approved for temperatures below -50 ° C refrigerant R23.
  • the oxidation-resistant lubricant is a highly stress-independent oil, in particular a liquid perfluoropolyether, z.
  • a perfluoropolyether having a linear structure is particularly advantageously advantageously, the perfluoropolyether having the chemical structure:
  • CFs - (O - CF 2 - CF 2) p - (O-CF2) q - O - CFs with q / p 1 .2
  • various lubricants are used fluorine compounds such as straight and branched per-.
  • the mixture of substances according to the invention is advantageously usable in the low-temperature stage of a cascaded refrigeration system which allows cooling to approximately -90.degree.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Physics & Mathematics (AREA)
  • Combustion & Propulsion (AREA)
  • Thermal Sciences (AREA)
  • Materials Engineering (AREA)
  • Lubricants (AREA)

Abstract

The invention relates to a mixture for a refrigerant circuit of a compression refrigeration system, said mixture comprising a natural refrigerant. The refrigerant has a proportion of at least 18% by mass of carbon dioxide in dinitrogen monoxide (nitrous oxide). In order to be able to use the refrigerant in a compressor, it is necessary, depending on the characteristics, to add a lubricant which is not oxidised by the refrigerant. The mixture can be used advantageously in a low temperature stage of a cooling cascade in order to enable evaporation temperatures of close to -90°C.

Description

Stoffgemisch für einen Kältemittelkreislauf einer Kompressionskälteanlage und dessen Verwendung  Mixture for a refrigerant circuit of a compression refrigeration system and its use
Die Erfindung betrifft ein Stoffgemisch für einen Kältemittelkreislauf in Kompressi- onskälteanlagen zur Kälteerzeugung, Dessen Hauptbestandteil ein natürliches Kältemittel ist. Das Stoffgemisch ist als Ersatz für das Kältemittel Trifluormethan (R23) bei Verdampfungstemperaturen unterhalb von -60 °C nutzbar ist. The invention relates to a mixture for a refrigerant circuit in compression refrigeration refrigeration systems, whose main component is a natural refrigerant. The substance mixture can be used as substitute for the refrigerant trifluoromethane (R23) at evaporation temperatures below -60 ° C.
Zur Kälteerzeugung im Temperaturbereich zwischen -55 °C und -90 °C können zwei- stufige Kaskadenkälteanlagen verwendet werden, die in der unteren Stufe, die auch als Tieftemperaturstufe bezeichnet wird, mit den Kältemitteln Trifluormethan CHF3 (R23), dem azeotropen Gemisch CHF3/C2F6 (R508) oder Ethan C2H6 (R170) betrieben werden. Ein wichtiger Gesichtspunkt von Kältemitteln ist, neben ihrer Toxizität und Brennbarkeit, deren Treibhauspotential, das durch den GWP-Wert (englisch: Global Warming Potential oder Greenhouse Warming Potential) beschrieben wird. Two-stage cascade refrigeration systems can be used for refrigeration in the temperature range between -55 ° C and -90 ° C; in the lower stage, which is also referred to as low-temperature, with the refrigerants trifluoromethane CHF3 (R23), the azeotropic mixture CHF3 / C2F6 (R508) or Ethan C2H6 (R170). An important aspect of refrigerants, apart from their toxicity and combustibility, is their global warming potential, which is described by the GWP value (English: Global Warming Potential or Greenhouse Warming Potential).
Im Hinblick auf die sich ändernden gesetzlichen Bestimmungen zum Einsatz fluorier- ter Gase, z. B. zu erwartende Restriktionen zur Anwendung von R23, und das Verwendungsverbot von chlorierten Stoffen wird fortwährend nach praktikablen und sicheren Alternativen gesucht. Hierbei ist seit längerer Zeit eine Tendenz zu natürlichen Kältemitteln zu verzeichnen. Insbesondere sind dabei die Kältemittel Kohlendioxid, Wasser, Kohlenwasserstoffe und Ammoniak von Interesse. In view of the changing legislation on the use of fluorinated gases, eg. For example, expected restrictions on the use of R23, and the ban on the use of chlorinated substances is constantly being sought for viable and safe alternatives. For some time now, there has been a trend towards natural refrigerants. In particular, the refrigerants carbon dioxide, water, hydrocarbons and ammonia are of interest.
Bedingt durch die Tripelpunkttemperatur des CO2 von -56,6 °C ist allerdings ein Einsatz in Kaskadenschaltungen unterhalb von ca. -55 °C für reines Kohlendioxid nicht mehr möglich. Es besteht dann die Gefahr, dass das Fluid nach bzw. im Drosselventil zu erstarren beginnt und der Kreislauf blockiert wird. Due to the triple point temperature of the CO2 of -56.6 ° C, however, a use in cascade circuits below about -55 ° C for pure carbon dioxide is no longer possible. There is then the danger that the fluid begins to solidify after or in the throttle valve and the circulation is blocked.
Aus der DE 10 2005 014 552 A1 ist ein auf CO2 basierendes Kältemittel für Kompressionskälteanlagen bekannt, das auch bei Temperaturen bis zu -70 °C einsetzbar ist. Dies wird erreicht durch die Zumischung von 30 Masse-% bis 15 Masse-% Di- stickstoffmonoxid. Abgesehen von dieser geringen Zumischung zu CO2 findet Distickstoffmonoxid, im Volksmund unter der Bezeichnung„Lachgas" bekannt, als Kältemittel für Kompressionskälteanlagen keine Anwendung. From DE 10 2005 014 552 A1 a CO2-based refrigerant for compression refrigeration systems is known, which can also be used at temperatures up to -70 ° C. This is achieved by adding 30% by mass to 15% by mass of nitric oxide monoxide. Apart from this small addition to CO2, nitrous oxide, popularly known as "nitrous oxide", is not used as a refrigerant for compression refrigeration systems.
Distickstoffmonoxid ist bei Verdampfungstemperaturen von -90 °C einsetzbar. Unter atmosphärischem Druck besteht jedoch die Gefahr der explosiven Zersetzung oberhalb einer Temperatur von ca. 565 °C. Durch verschiedene Einflussgrößen (z. B. erhöhter Druck, katalytische Faktoren) kann die Zerfallstemperatur von Lachgas sogar noch wesentlich erniedrigt werden. In der Vergangenheit gab es aufgrund dessen mit Lachgas bereits schwere Unfälle. Nitrous oxide can be used at evaporation temperatures of -90 ° C. At atmospheric pressure, however, there is the danger of explosive decomposition above a temperature of about 565 ° C. By different factors (eg increased pressure, catalytic factors), the decomposition temperature of nitrous oxide can even be significantly reduced. In the past, there were already serious accidents with nitrous oxide.
In der Regel liegt die Obergrenze der Verdichterendtemperatur in einer Kompressionskälteanlage bei 150 °C und somit in einem für Lachgas unkritischen Temperatur- bereich. Im Falle eines Verdichterschadens kann die Temperatur jedoch lokal schnell auf über 600 °C steigen, sodass eine reale Gefahr einer Lachgasexplosion bei einer mit Distickstoffmonoxid als Kältemittel betriebenen Kompressionskälteanlage bleibt. Aus diesem Grunde bestehen begründete sicherheitstechnische Bedenken gegen den Einsatz von reinem N2O in Kälteanlagen. As a rule, the upper limit of the compressor end temperature in a compression refrigeration system is 150 ° C and thus in a non-critical temperature range for nitrous oxide. However, in the case of compressor damage, the temperature may rise locally to over 600 ° C, leaving a real danger of a nitrous oxide explosion in a compression refrigeration system operated as a refrigerant with dinitrogen monoxide. For this reason, there are reasonable safety concerns about the use of pure N2O in refrigeration systems.
Wünschenswert wäre ein auf Lachgas basierendes Kältemittel für Kompressionskälteanlagen, das sowohl explosionssicher als auch bei Temperaturen unterhalb -70 °C einsetzbar ist. Der Erfindung liegt die Aufgabe zugrunde, ein kostengünstiges, unbrennbares, insbesondere explosionssicheres Stoffgemisch für Kompressionskälteanlagen zu schaffen, welches ein natürliches Kältemittel als Ersatz für R23 (Trifluormethan) beinhaltet, mittels dessen Temperaturen unterhalb -70 °C im Verdampfer erreichbar sein sollen, wobei das Kältemittel außerdem ein im Vergleich zu R23 geringes Treibhauspotential und eine gute Energieeffizienz aufweisen sowie ein geringes Prozessdruckverhältnis ermöglichen soll. Diese Aufgabe wird durch die kennzeichnenden Merkmale des Anspruches 1 gelöst; weitere vorteilhafte Ausführungen bzw. Verwendungen der Erfindung ergeben sich aus den Ansprüchen 2 bis 5 bzw. 6. Das erfindungsgemäße Stoffgemisch für einen Kältemittelkreislauf einer Kompressionskälteanlage besteht aus einem Kältemittel und einem inerten Schmiermittel. Das Kältemittel wiederum besteht aus Distickstoffmonoxid und Kohlendioxid. Der Anteil von Kohlendioxid im Kältemittel liegt im Bereich zwischen 18 Masse-% und 30 Masse-%. Der verbleibende Anteil des Kältemittels, d. h. 70 bis 82 Masse-%, ist Distick- stoffmonoxid. It would be desirable to have a nitrous oxide-based refrigerant for compression refrigeration systems that is both explosion-proof and usable at temperatures below -70 ° C. The invention has for its object to provide a cost-effective, incombustible, especially explosion-proof mixture for compression refrigeration systems, which includes a natural refrigerant as a replacement for R23 (trifluoromethane), by means of which temperatures below -70 ° C should be achievable in the evaporator, wherein the refrigerant Moreover, compared with R23, it has a low global warming potential, good energy efficiency and a low process pressure ratio. This object is solved by the characterizing features of claim 1; Further advantageous embodiments or uses of the invention will become apparent from the claims 2 to 5 and 6. The mixture of substances according to the invention for a refrigerant circuit of a compression refrigeration system consists of a refrigerant and an inert lubricant. The refrigerant in turn consists of nitrous oxide and carbon dioxide. The proportion of carbon dioxide in the refrigerant is in the range between 18% by mass and 30% by mass. The remaining proportion of the refrigerant, ie 70 to 82% by mass, is dinitrogen monoxide.
Die beiden Komponenten Kohlendioxid und Distickstoffmonoxid sind im flüssigen Zustand vollständig miteinander mischbar. Um den Phasenübergang flüssiggasförmig möglichst nahe am Tripelpunkt des Distickstoffmonoxids und damit eine Verdampfungstemperatur im Verdampfer der Kälteanlage von ca. -90 °C zu erhalten, ist die Kohlendioxidkonzentration möglichst gering zu wählen. The two components carbon dioxide and dinitrogen monoxide are completely miscible in the liquid state. In order to obtain the phase transition liquid-gas as close as possible to the triple point of the nitrous oxide and thus an evaporation temperature in the evaporator of the refrigeration system of about -90 ° C, the carbon dioxide concentration is to be selected as low as possible.
Überraschenderweise hat sich gezeigt, dass in einer im unterkritischen Betrieb geführten Kompressionskälteanlage, d. h. mit einem auf der Hochdruckseite des Ver- dichters auftretendem Druck von maximal 55 bar und einer Temperatur von maximal 150 °C, die - z. B. im Havariefall - bei 565 °C auftretende explosive Zersetzung von Distickstoffmonoxid bereits bei einer Zumischung von 17 Masse-% Kohlendioxid unterdrückt ist. Erfindungsgemäß beträgt der C02-Anteil also mindestens 17 Masse-%. Da die Zugabe eines Sicherheitszuschlages von einem Masse-% sinnvoll ist, beträgt der Anteil an CO2 vorzugsweise mindestens 18 Masse-%. Um jedoch die Vorteile des Distickstoffmonoxids als Kältemittel bestmöglich nutzen zu können, ist ein C02-Anteil von maximal 20 Masse-% bevorzugt, wobei idealerweise ein Anteil des Kohlendioxids von 18 Masse-% vorgesehen ist. Surprisingly, it has been found that in a compression refrigeration plant operated in subcritical operation, i. H. with a pressure of up to 55 bar and a maximum temperature of 150 ° C occurring on the high-pressure side of the compressor, which -. B. in the event of an accident - occurring at 565 ° C explosive decomposition of nitrous oxide is suppressed already at an admixture of 17 mass% carbon dioxide. Thus, according to the invention, the proportion of CO 2 is at least 17% by mass. Since the addition of a safety margin of one mass% makes sense, the proportion of CO2 is preferably at least 18% by mass. However, in order to be able to make the best possible use of the advantages of nitrous oxide as a refrigerant, a C02 proportion of not more than 20% by mass is preferred, ideally providing a carbon dioxide fraction of 18% by mass.
Zusätzlich wird zu dem Kältemittel des Stoffgemischs ein geeignetes inertes In addition to the refrigerant of the mixture mixture is a suitable inert
Schmiermittel zur Verdichterschmierung zugegeben. Das Schmiermittel ist erforderlich, um das erfindungsgemäße Stoffgemisch in einer Kompressionskälteanlage mit Verdichter verwenden zu können, wobei das zugefügte Schmiermittel gegenüber dem als starkes Oxidationsm ittel wirkenden Distickstoffmonoxid oxidationsbeständig, d. h. inert, ist. Bevorzugt liegen eine partielle Löslichkeit des Schmiermittels im flüssigen Kältemittel sowie eine partielle Löslichkeit des Kältemittels im flüssigen Lubricant added to the compressor lubrication. The lubricant is required to the inventive mixture in a compression refrigeration system with Compressors to be able to use, wherein the lubricant added to the acting as a strong Oxidungsm title dinitrogen monoxide resistant to oxidation, that is inert, is. Preference is given to a partial solubility of the lubricant in the liquid refrigerant and a partial solubility of the refrigerant in the liquid
Schmiermittel vor, sodass im Kältekreislauf der Schmiermittelrücktransport zum Kompressor gewährleistet wird. Lubricant before, so that in the refrigeration cycle the lubricant return to the compressor is ensured.
Der Vorteil dieses Stoffgemischs ist das vergleichsweise geringe Treibhauspotential des Kältemittels, mit einem GWP-Wert von nur etwa 200 gegenüber R23 mit einem GWP-Wert von 14800. Aufgrund seines Hauptbestandteils Distickstoffmonoxid sind mit dem Kältemittel Verdampfungstemperaturen von nahezu -90 °C ermöglicht, sodass es in modifizierten Kompressionskälteanlagen einsetzbar ist, die derart tiefe Temperaturen generieren sollen. Distickstoffmonoxid und Kohlendioxid sind beide natürlich vorkommende, in intensiven toxikologischen Untersuchungen als ungiftig eingestufte Verbindungen und gleichfalls kostengünstig beziehbar, wodurch das erfindungsgemäße Kältemittel sowohl in niedrigen Dosen für die menschliche Gesundheit unbedenklich, als auch in ausreichenden Mengen zur Anwendung in Kompressionskälteanlagen für Tempera- turbereiche unterhalb -50 °C herstellbar ist. Somit ist es als ein kostengünstiger Ersatz für das bislang für Temperaturen unterhalb von -50 °C noch zugelassene Kältemittel R23 einsetzbar. The advantage of this substance mixture is the comparatively low global warming potential of the refrigerant, with a GWP of only about 200 compared to R23 with a GWP value of 14800. Due to its main component nitrous oxide, the evaporation temperatures of almost -90 ° C are possible with the refrigerant, so it can be used in modified compression refrigeration systems to generate such low temperatures. Nitrous oxide and carbon dioxide are both naturally occurring compounds which have been classified as nontoxic in intensive toxicological investigations and are also available at low cost, as a result of which the refrigerant according to the invention is harmless to human health both in low doses and in sufficient quantities for use in compression refrigeration systems for temperature ranges below. 50 ° C can be produced. Thus, it can be used as a cost-effective replacement for the previously approved for temperatures below -50 ° C refrigerant R23.
In einer vorteilhaften Ausgestaltung der Erfindung ist das oxidationsbeständige Schmiermittel ein hochgradig belastungsunabhängiges Öl, insbesondere ein flüssiger Perfluorpolyether, z. B. ein Perfluorpolyether mit einer linearen Struktur. Besonders vorteilhaft besitzt der Perfluorpolyether die chemische Struktur: In an advantageous embodiment of the invention, the oxidation-resistant lubricant is a highly stress-independent oil, in particular a liquid perfluoropolyether, z. For example, a perfluoropolyether having a linear structure. Particularly advantageously, the perfluoropolyether has the chemical structure:
CFs - ( O - CF2 - CF2 )p - ( O-CF2 )q- O - CFs mit q / p = 1 .2 Es können auch verschiedene Schmiermittel, wie unverzweigte und verzweigte Per- fluorverbindungen verwendet werden. Das erfindungsgemäße Stoffgemisch ist vorteilhaft in der Tieftemperaturstufe einer kaskadierten Kälteanlage, die eine Abkühlung auf annähernd -90 °C erlaubt, verwendbar. CFs - (O - CF 2 - CF 2) p - (O-CF2) q - O - CFs with q / p = 1 .2 Also, various lubricants are used fluorine compounds such as straight and branched per-. The mixture of substances according to the invention is advantageously usable in the low-temperature stage of a cascaded refrigeration system which allows cooling to approximately -90.degree.

Claims

Stoffgemisch für einen Kältemittelkreislauf einer Kompressionskälteanlage, dadurch gekennzeichnet, dass Mixture for a refrigerant circuit of a compression refrigeration system, characterized in that
das Stoffgemisch aus einem Kältemittel, bestehend aus Kohlendioxid und Di- stickstoffmonoxid, und einem inerten Schmiermittel besteht, wobei the mixture of a refrigerant consisting of carbon dioxide and nitric oxide, and an inert lubricant, wherein
der Anteil von Kohlendioxid im Kältemittel im Bereich zwischen 17 Masse-% und 30 Masse-% liegt, und the proportion of carbon dioxide in the refrigerant ranges between 17% and 30% by mass, and
das Schmiermittel eine partielle Löslichkeit im flüssigen Kältemittel sowie das Kältemittel eine partielle Löslichkeit im Schmiermittel besitzen. the lubricant has a partial solubility in the liquid refrigerant and the refrigerant has a partial solubility in the lubricant.
Stoffgemisch nach Anspruch 1 , dadurch gekennzeichnet, dass der Anteil von Kohlendioxid im Kältemittel zwischen 18 Masse-% und maximal 20 Masse-% beträgt. A mixture according to claim 1, characterized in that the proportion of carbon dioxide in the refrigerant is between 18% by mass and not more than 20% by mass.
Stoffgemisch nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass der Anteil von Kohlendioxid im Kältemittel 18 Masse-% beträgt. Mixture of substances according to claim 1 or 2, characterized in that the proportion of carbon dioxide in the refrigerant is 18% by mass.
Stoffgemisch nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass das Schmiermittel gegenüber dem Distickstoffmonoxid oxidationsbe- ständig ist. Mixture of substances according to one of claims 1 to 3, characterized in that the lubricant is oxidation resistant to the dinitrogen monoxide.
Stoffgemisch nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass das Schmiermittel ein flüssiger Perfluorpolyether ist. Mixture of substances according to one of claims 1 to 4, characterized in that the lubricant is a liquid perfluoropolyether.
Verwendung des Stoffgemischs nach einem der Ansprüche 1 bis 5 in der Tieftemperaturstufe einer Kaskadenkälteanlage zur Erzeugung einer Temperatur im Bereich zwischen -70 °C und -90 °C. Use of the substance mixture according to one of claims 1 to 5 in the low-temperature stage of a cascade refrigeration plant for producing a temperature in the range between -70 ° C and -90 ° C.
PCT/DE2018/100238 2017-03-28 2018-03-16 Mixture for a refrigerant circuit of a compression unit and the use thereof WO2018177465A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE102017106651 2017-03-28
DE102017106651.9 2017-03-28
DE102018105862.4 2018-03-14
DE102018105862.4A DE102018105862A1 (en) 2017-03-28 2018-03-14 Mixture for a refrigerant circuit of a compression refrigeration system and its use

Publications (1)

Publication Number Publication Date
WO2018177465A1 true WO2018177465A1 (en) 2018-10-04

Family

ID=63524596

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE2018/100238 WO2018177465A1 (en) 2017-03-28 2018-03-16 Mixture for a refrigerant circuit of a compression unit and the use thereof

Country Status (2)

Country Link
DE (1) DE102018105862A1 (en)
WO (1) WO2018177465A1 (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005014552A1 (en) 2005-03-24 2006-09-28 Technische Universität Dresden Natural binary cooling agent, useful as refrigerant to refrigerate plants in compression cascade system, comprises carbon dioxide in combination with nitrogen-dioxide

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005014552A1 (en) 2005-03-24 2006-09-28 Technische Universität Dresden Natural binary cooling agent, useful as refrigerant to refrigerate plants in compression cascade system, comprises carbon dioxide in combination with nitrogen-dioxide

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
KRUSE H ET AL: "The natural fluid nitrous oxide-an option as substitute for low temperature synthetic refrigerants", INTERNATIONAL JOURNAL OF REFRIGERATION, ELSEVIER, PARIS, FR, vol. 29, no. 5, 1 August 2006 (2006-08-01), pages 799 - 806, XP027948401, ISSN: 0140-7007, [retrieved on 20060801] *
LIPPOLD, H.; HEIDE, R.: "Distickstoffoxid (Lachgas) als Tieftemperaturkältemittel", DKV-TAGUNGSBERICHT 2002 : MAGDEBURG, 20. - 22. NOVEMBER 2002; BD. 2,1: ARBEITSABTEILUNG II.1, vol. 29, 22 November 2002 (2002-11-22), pages 143 - 154, XP009506640, ISBN: 3-932715-34-9 *

Also Published As

Publication number Publication date
DE102018105862A1 (en) 2018-10-04

Similar Documents

Publication Publication Date Title
DE69909424T2 (en) Single circuit device with multi-component coolant for low temperature liquefaction of industrial gas
DE69916224T2 (en) Hybrid refrigeration device for cryogenic liquefaction of industrial gas
DE60109234T2 (en) Compression method for cryogenic cooling with a multi-component coolant and a lubricant
DE2543291A1 (en) PROCESS FOR PROCESSING A NATURAL GAS FLOW
DE4116274A1 (en) Environmentally-acceptable, non-CFC refrigerant - consists of mixt. of carbon di:oxide and partly fluorinated hydrocarbon(s), esp. R32, R143A, R125 etc.
DE102017216363A1 (en) refrigerant
DE1501695A1 (en) Process for the liquefaction of a volatile gas
EP0000391A1 (en) Process for the production of nitrous oxide
WO2014067652A2 (en) Method for cooling a hydrocarbon-rich fraction
WO2018177465A1 (en) Mixture for a refrigerant circuit of a compression unit and the use thereof
DE102014012316A1 (en) Process for cooling a hydrocarbon-rich fraction
DE102015101415A1 (en) Process and plant for the purification of raw gases by means of physical gas scrubbing
DE1126435B (en) Process for liquefying a gas
DE102005014552A1 (en) Natural binary cooling agent, useful as refrigerant to refrigerate plants in compression cascade system, comprises carbon dioxide in combination with nitrogen-dioxide
DE60035904T2 (en) FLUOROCCOQUE HYDROGEN CONTAINING EVAPORATOR COOLER
DE102014104110A1 (en) Working mixture for devices for heat transport and method for operating a refrigerant circuit of the device
DE69929331T2 (en) COOLANT FOR SUPER LOW TEMPERATURE COOLING
DE3141202C2 (en)
DE2842899A1 (en) STEAM CIRCUIT
WO2018091146A1 (en) Process and apparatus for synthesis gas fractionation using an acidic gas scrub and a cryogenic separating process
DE2433922A1 (en) METHOD AND DEVICE FOR THE PRODUCTION OF NITROGEN BY SEPARATION OF AIR
EP1084207B1 (en) Method for producing cold in a temperature range of 90 to 110 k.
DE102019119194A1 (en) Refrigerant for a chiller
DE10331978A1 (en) Process for compressing the working fluid during a water-steam combination process in multi-stage turbocompressors comprises intercooling in the individual compressor stages by the addition of a coolant to the working fluid
DE2638650C2 (en) Process for the separation of tetrafluoroethylene from gas mixtures

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18720955

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 18720955

Country of ref document: EP

Kind code of ref document: A1