Nonflammable mixed refrigerants (MR) for use with very low temperature throttle-cycle refrigeration systems

Abstract

Refrigerants containing hcfc's are replaced with new blends by using r-236fa and r-125, or r-125 with r-245fa, or r-236ea, or r-134a with r-236fa in place of hcfc's. No hardware or oil composition changes are required to maintain temperatures, pressures and capacity substantially unchanged in a refrigeration system.

Description

It has been noted that R-125 is more soluble with other components like R-23, R-124 and R-123. Thus, in accordance with an embodiment of the invention, this characteristic helps to reduce freezing temperatures of the blend at low temperature in the system.

In accordance with an embodiment of the invention, non-flammable, environmentally friendly chlorine-free pure refrigerants may be selected from the group HFC, FC, and HFE (ethers).

A related invention, disclosed by U.S. Provisional Application Ser. No. 60/214,565, uses an evaporator pressure regulating valve, installed in the compressor suction line 122, to prevent freezeout of the refrigerant components by acting to maintain at least a minimum suction pressure to the refrigeration process, thereby keeping the suction pressure of the system from dropping too low. As the suction pressure gets lower the temperature gets colder. If a freezeout condition occurs the suction pressure tends to drop creating positive feedback and further reducing the temperature, causing even more freezeout. Such a valve was used with Blends B and C of Table 1 to assure that freezeout was prevented.

With the exception of E-347, and R-4112 all refrigerants listed are designated in accordance with American Society of Heating and Refrigeration and Air Conditioning Engineering (ASHRAE) standard number 34.

E-347 is known as 1-(methoxy)-1,1,2,2,3,3,3-heptafluoropropane (also CH3—O—CF2—CF2—CF3), 3M product reference Hydrofluoroether 301. At this time a permissible exposure limit (PEL) is not yet established for this compound. Therefore it is not known if it meets the criteria of a nontoxic refrigerant (PEL>400 ppm). If it is discovered that this compound has a PEL below 400 ppm then it can be diluted with other components to produce a refrigerant mixture that has an overall PEL that is considered nontoxic.

R-4112 is known as dodecafluoropentane (also CF3CF2CF2CF2CF3).

A third embodiment, in accordance with the invention, is required for a refrigeration system based on an oil-lubricated compressor operating with one of the nonflammable MR formulations of Table 3 through 8 at temperatures below 200 K. Therefore, an oil must be added to the MR formulation, in accordance with the invention. Furthermore, it is required that the oil insure long term compressor operation and avoid freeze out of the refrigerant contaminated with oil.

Compressors designed to operate with mixed refrigerants formulated of HFC components should use either polyolesters (POE) or polyalkylene glycols (PAG) type of oil to insure long term operation. A typical pour point temperature for this oil is higher then 220 K (−53 C.). Also in this temperature range oils of this type are miscible with pure and mixed refrigerants formulated of HFCs. For example, POE oil Solest LT-32 has a pour point temperature of 223 K and is fully miscible with pure R-23. Mixed refrigerants R-404a (combination of R-125, R-143a and R-134a) and R-407c (combination of R-32, R-125 and R-134a) are also fully miscible with this oil at T>223 K). Table 9 below shows sample refrigerant formulations and associated freezing temperature, pure and mixed refrigerants with residual oil LT-32 (CPI Engineering, Solest LT-32) are included.

It was found that a small amount of oil LT 32 can be mixed with the mixed refrigerants at very low temperatures without freezeout. This is shown in Table 9. This allows long term operation of the system when equipped with an oil lubricated compressor and properly sized oil separators to keep the oil concentrations below the levels shown in Table 9. Alternatively, in an auto-refrigerating cascade system, the use of phase separators in the refrigeration process can also be used to limit the concentration of oil mixed with very low temperature refrigerant flowing through the coldest parts of the system. The efficiency of the phase separators needs to be sufficiently high that the oil concentration does not exceed the limits shown in Table 9.

Other oils which exhibit similar properties are commercially available and are considered to fall within the scope of this invention.

Claims

1. refrigerant blends not containing hcfc for use in a very low temperature refrigeration system, said refrigerant blends in mol percent comprising:

		Overall range
	Component	(mole %)
	Argon	4-36
	r-14	10-55
	r-23	10-50
	r-125	5-20
	r-236fa	7-40

!

2. refrigerant blends as in claim 1 and further comprising at least one additional component in each said blend, the components maintaining the same proportions relative to each other after addition of said additional component.

3. refrigerant blends as in claim 1, wherein said refrigeration system is a compressor cycle in one of an autorefrigerating cascade having a liquid/vapor phase separator, throttle device refrigeration system, and a Klimenko type system.

4. refrigerant blends as in claim 1 wherein said refrigerating system alternatively permits flow of cold refrigerant or flow of hot refrigerant to an evaporator.

5. refrigerant blends not containing HCF's hcfc as in claim 1, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, in said earlier blends HCF's hcfc being greater than 0 mol percent.

6. refrigerant blends as in claim 1, wherein said refrigeration system includes an object being cooled by the refrigerant, said object being at least one of

(a) a metal element in a vacuum chamber freezing out and trapping undesired gasses such as water vapor,

(b) a heat exchanger removing heat from a secondary fluid stream including at least one of a liquid, gas, condensing gas, and condensing gas mixture,

(c) a metal element having internal refrigerant flow passages and cooling at least one of a silicon wafer, piece of glass, plastic piece and an aluminum disc with or without a magnetic coating on it, and

(d) a biological freezer to at least one of freeze and store biological tissues.

7. refrigerant blends as in claim 1, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

8. refrigerant blends not containing hcfc's , for use in a very low temperature refrigeration system where the evaporator temperature is as low as 105 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mol)
1	At least one of neon (Ne) or	0.0-10.0
	helium (He)
2	At least one of argon (Ar) or	10.0-45.0
	nitrogen (N2)
3	r-14 (CF4)	20.0-50.0
4	r-23 (CHF3)	10.0-30.0
5	r-125 (C2HF5)	8.0-15.0
6	r-134a	0.0-5.0
7	Other high boiling components:	0.0-3.0
	at least one of r-236fa, E-347,
	r-245fa, r-4112

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

9. refrigerant blends as in claim 8 and further comprising at least one additional component in each said blend, the components maintaining the same proportions relative to each other after addition of said additional component.

10. refrigerant blends as in claim 8, wherein said refrigeration system is a compressor cycle in one of an autorefrigerating cascade having a liquid/vapor phase separator, throttle device refrigeration system, and a Klimenko type system.

11. refrigerant blends as in claim 8 wherein said refrigerating system alternatively permits flow of cold refrigerant or flow of hot refrigerant to an evaporator.

12. refrigerant blends not containing HCF's hcfc as in claim 8, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, in said earlier blends HCF's hcfc being greater than 0 mol percent.

13. refrigerant blends as in claim 8, wherein said refrigeration system includes an object being cooled by the refrigerant, said object being at least one of

(a) a metal element in a vacuum chamber freezing out and trapping undesired gasses such as water vapor,

(b) a heat exchanger removing heat from a secondary fluid stream including at least one of a liquid, gas, condensing gas, and condensing gas mixture,

(c) a metal element having internal refrigerant flow passages and cooling at least one of a silicon wafer, piece of glass, plastic piece and an aluminum disc with or without a magnetic coating on it, and

(d) a biological freezer to at least one of freeze and store biological tissues.

14. refrigerant blends as in claim 8, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

15. refrigerant blends not containing hcfc's , for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 118 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mole)
1	At least one of argon (Ar) or	10.0-40.0
	nitrogen (N2)
2	r-14	20.0-50.0
3	r-23	0.0-35.0
4	r-125	0.0-10.0
5	r-134a	0.0-6.0
6	At least one of E-347, r-4112
	r-236fa, or r-245fa.

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least one of E-347, r-4112, r-236fa, or r-245fa is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

16. refrigerant blends as in claim 15 and further comprising at least one additional component in each said blend, the components maintaining the same proportions relative to each other after addition of said additional component.

17. refrigerant blends as in claim 15, wherein said refrigeration system is a compressor cycle in one of an autorefrigerating cascade having a liquid/vapor phase separator, throttle device refrigeration system, and a Klimenko type system.

18. refrigerant blends as in claim 15 wherein said refrigerating system alternatively permits flow of cold refrigerant or flow of hot refrigerant to an evaporator.

19. refrigerant blends not containing HCF's hcfc as in claim 3 15, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, in said earlier blends HCF's hcfc being greater than 0 mol percent.

20. refrigerant blends as in claim 15, wherein said refrigeration system includes an object being cooled by the refrigerant, said object being at least one of

(a) a metal element in a vacuum chamber freezing out and trapping undesired gasses such as water vapor,

(b) a heat exchanger removing heat from a secondary fluid stream including at least one of a liquid, gas, condensing gas, and condensing gas mixture,

(c) a metal element having internal refrigerant flow passages and cooling at least one of a silicon wafer, piece of glass, plastic piece and an aluminum disc with or without a magnetic coating on it, and

(d) a biological freezer to at least one of freeze and store biological tissues.

21. refrigerant blends as in claim 15, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

22. refrigerant blends not containing hcfc's , for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 130 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mole)
1	At least one of argon (Ar) or	2.0-40.0%
	nitrogen (N2)
2	r-14	10.0-50.0%
3	r-23	10.0-40.0%
4	r-125	0.0-40.0%
5	r-134a	0.0-15.0%
6	At least one of r-245fa, r-	0.0-30.00% 10.0%
	236fa, E-347, or r-4112.

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least one of r-245fa, r-236fa, E-347, or r-4112 is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

23. refrigerant blends as in claim 22 and further comprising at least one additional component in each said blend, the components maintaining the same proportions relative to each other after addition of said additional component.

24. refrigerant blends as in claim 22, wherein said refrigeration system is a compressor cycle in one of an autorefrigerating cascade having a liquid/vapor phase separator, throttle device refrigeration system, and a Klimenko type system.

25. refrigerant blends as in claim 22 wherein said refrigerating system alternatively permits flow of cold refrigerant or flow of hot refrigerant to an evaporator.

26. refrigerant blends not containing HCF's hcfc as in claim 22, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, in said earlier blends HCF's hcfc being greater than 0 mol percent.

27. refrigerant blends as in claim 22, wherein said refrigeration system includes an object being cooled by the refrigerant, said object being at least one of

(a) a metal element in a vacuum chamber freezing out and trapping undesired gasses such as water vapor,

(b) a heat exchanger removing heat from a secondary fluid stream including at least one of a liquid, gas, condensing gas, and condensing gas mixture,

(c) a metal element having internal refrigerant flow passages and cooling at least one of a silicon wager, piece of glass, plastic piece and an aluminum disc with or without a magnetic coating on it, and

(d) a biological freezer to at least one of freeze and store biological tissues.

28. refrigerant blends as in claim 4 22, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

29. refrigerant blends not containing hcfc's , for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 140 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mol)
1	At least one of argon (Ar) or	2.0-40.0%
	nitrogen (N2)
2	r-14	10.0-50.0%
3	r-23	10.0-40.0%
4	r-125	0.0-30.0%
5	r-134a	0.0-15.0%
5 6	At least one of r-236fa, r-	0.0-10.0% 15.0%
	245fa, E-347, or r-4112.

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least one of r-236fa, r-245fa, E-347, or r-4112 is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

30. refrigerant blends as in claim 29 and further comprising at least one additional component in each said blend, the components maintaining the same proportions relative to each other after addition of said additional component.

31. refrigerant blends as in claim 29, wherein said refrigeration system is a compressor cycle in one of an autorefrigerating cascade having a liquid/vapor phase separator, throttle device refrigeration system, and a Klimenko type system.

32. refrigerant blends as in claim 29 wherein said refrigerating system alternatively permits flow of cold refrigerant or flow of hot refrigerant to an evaporator.

33. refrigerant blends not containing HCF's hcfc as in claim 29, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, in said earlier blends HCF's hcfc being greater than 0 mol percent.

34. refrigerant blends as in claim 29, wherein said refrigeration system includes an object being cooled by the refrigerant, said object being at least one of

(a) a metal element in a vacuum chamber freezing out and trapping undesired gasses such as water vapor,

(b) a heat exchanger removing heat from a secondary fluid stream including at least one of a liquid, gas, condensing gas, and condensing gas mixture,

(c) a metal element having internal refrigerant flow passages and cooling at least one of a silicon wafer, piece of glass, plastic piece and an aluminum disc with or without a magnetic coating on it, and

35. refrigerant blends as in claim 29, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

36. refrigerant blends not containing hcfc's , for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 155 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mole)
1	At least one of argon (Ar) or	0.0-40.0%
	nitrogen (N2)
2	r-14	5.0-50.0%
3	r-23	5.0-40.0%
4	r-125	0.0-40.0%
5	r-134a	0.0-30.0%
6	At least one of r-236fa, or	0.0-30.0%
	r-245fa
7	At least one of E-347 or r-4112	0.0-20.0%

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least one of r-236fa, r-245fa, E-347, or r-4112 is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

37. refrigerant blends as in claim 36 and further comprising at least one additional component in each said blend, the components maintaining the same proportions relative to each other after addition of said additional component.

38. refrigerant blends as in claim 36, wherein said refrigeration system is a compressor cycle in one of an autorefrigerating cascade having a liquid/vapor phase separator, throttle device refrigeration system, and a Klimenko type system.

39. refrigerant blends as in claim 36 wherein said refrigerating system alternatively permits flow of cold refrigerant or flow of hot refrigerant to an evaporator.

40. refrigerant blends not containing HCF's hcfc as in claim 36, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, in said earlier blends HCF's hcfc being greater than 0 mol percent.

41. refrigerant blends as in claim 36, wherein said refrigeration system includes an object being cooled by the refrigerant, said object being at least one of

(d) a metal element in a vacuum chamber freezing out and trapping undesired gasses such as water vapor,

(e) a heat exchanger removing heat from a secondary fluid stream including at least one of a liquid, gas, condensing gas, and condensing gas mixture,

(f) a metal element having internal refrigerant flow passages and cooling at least one of a silicon wafer, piece of glass, plastic piece and an aluminum disc with or without a magnetic coating on it, and

42. refrigerant blends as in claim 36, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

43. refrigerant blends not containing hcfc for use in a very low temperature refrigeration system, said refrigerant blends selected from the group comprising blend A, blend B, blend C, and blend D where the components of each blend in mol percent are as follows:

	Molar Fraction (percent)
	Component	blend A	blend B	blend C	blend D
	Argon	13	24	18	8
	r-14	34	26	35	24
	r-23	28	22	21	32
	r-125	11	11	12	11
	r-236fa	14	17	14	25.

!

44. A refrigerant blend free of hcfc containing a mixed refrigerant comprising a fluorocarbon, at least one gas selected from the group consisting of Ar and N₂, and at least one of r-236fa, r-245fa, HFE, and r-4112, the at least one r-236fa, r-245fa, HFE, and r-4112 in a total amount not greater than 3.0 mol %; wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system; and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

45. The refrigerant blend of claim 44, wherein the refrigerant blend is configured for use in a very low temperature refrigeration system.

46. The refrigerant blend of claim 44, wherein HFE comprises E-347.

47. The refrigerant blend of claim 44, wherein the fluorocarbon comprises r-14.

48. The refrigerant blend of claim 44, further comprising a lubricant oil.

49. The refrigerant blend of claim 48, comprising approximately 1 wt % to 10 wt % of the lubricant oil.

50. The refrigerant blend of claim 48, wherein the lubricant oil comprises POE-type lubricant oil.

51. The refrigerant blend of claim 48, wherein the lubricant oil comprises PAG-type lubricant oil.

52. A refrigerant blend free of hcfc containing a mixed refrigerant comprising:

at least one of Ar or N₂;

r-14;

r-125;

r-23; and

at least one of r-236fa, r-245fa, E-347, or r-4112.

53. The refrigerant blend of claim 52, wherein the refrigerant blend is configured for use in a very low temperature refrigeration system.

54. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 55.0 mol % of the r-14.

55. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 40.0 mol % of the r-23.

56. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 40.0 mol % of the r-125.

57. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 40.0 mol % of the at least one of r-236fa, r-245fa, E-347, or r-4112.

58. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 30.0 mol % of the at least one of r-236fa, r-245fa, E-347, or r-4112.

59. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 10.0 mol % of the at least one of r-236fa, r-245fa, E-347, or r-4112.

60. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 6.0 mol % of the at least one of r-236fa, r-245fa, E-347, or r-4112.

61. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 3.0 mol % of the at least one of r-236fa, r-245fa, E-347, or r-4112.

62. The refrigerant blend of claim 52, wherein the mixed refrigerant further comprises r-134a.

63. The refrigerant blend of claim 62, wherein the mixed refrigerant comprises not greater than 15.0 mol % of the r-134a.

64. The refrigerant blend free of hcfc containing a mixed refrigerant comprising a fluorocarbon, E-347, and at least one gas selected from the group consisting of Ar or N₂.

65. The refrigerant blend of claim 64, wherein the refrigerant blend is configured for use in a very low temperature refrigeration system.

66. A method of refrigerating, the method comprising:

using an hcfc-free refrigerant blend in a refrigeration system, the hcfc-free refrigerant blend containing a mixed refrigerant comprising:

at least one of Ar or N₂;

r-14;

r-125;

r-23; and

at least one of r-236fa, r-245fa, E-347, or r-4112; and

cooling an evaporator of the refrigeration system.

67. The method of claim 66, wherein the refrigeration system is designed for use of hcfc-containing refrigerant blends, wherein the hcfc-free refrigerant blend is a replacement refrigerant.

68. The method of claim 66, wherein cooling comprises cooling the evaporator to a temperature as low as 155K.

69. The method of claim 66, wherein cooling comprises cooling the evaporator to a temperature as low as 140K.

70. The method of claim 66, wherein cooling comprises cooling the evaporator to a temperature as low as 130K.

71. The method of claim 66, wherein cooling comprises cooling the evaporator to a temperature as low as 118K.

72. The method of claim 66, wherein the hcfc-free refrigerant blend further comprises lubricant oil.

73. The method of claim 72, wherein the hcfc-free refrigerant blend comprises approximately 1 wt % to 10 wt % of the lubricant oil.

74. The method of claim 72, wherein the lubricant oil comprises POE-type lubricant oil.

75. The method of claim 72, wherein the lubricant oil comprises PAG-type lubricant oil.

76. A refrigerant blend free of hcfc comprising (i) a mixed refrigerant comprising at least one of r-236fa and r-245fa, and (ii) lubricant oil, wherein the refrigerant blend has a freezing temperature not greater than 150.0K.

77. The refrigerant blend of claim 76, wherein the lubricant oil comprises POE-type lubricant oil.

78. The refrigerant blend of claim 76, wherein the refrigerant blend comprises approximately 1 wt % to 10 wt % of the lubricant oil.

79. The refrigerant blend of claim 76, wherein the freezing temperature is not greater than 140K.

80. The refrigerant blend of claim 76, further comprising at least one gas selected from Ar and N₂.

81. The refrigerant blend of claim 76, further comprising r-14.

82. The refrigerant blend of claim 76, further comprising r-23.

83. The refrigerant blend of claim 76, further comprising r-125.

84. The refrigerant blend of claim 76, further comprising r-218.

85. A refrigerant blend free of hcfc containing a mixed refrigerant comprising:

at least one of Ar or N₂;

r-14;

r-23; and

r-125.

86. The refrigerant blend of claim 85, wherein the refrigerant blend is configured for use in a very low temperature refrigeration system.

87. The refrigerant blend of claim 85, further comprising r-134a.

88. A refrigerant blend free of hcfc containing a mixed refrigerant comprising:

r-14;

r-125;

r-23; and

at least one of r-236fa, r-245fa, E-347, or r-4112.

89. The refrigerant blend of claim 88, wherein the refrigerant blend is configured for use in a very low temperature refrigeration system.

90. The refrigerant blend of claim 88, further comprising r-134a.

91. The refrigerant blend of claim 44, wherein the mixed refrigerant further comprises at least one of Ne or He.

92. The refrigerant blend of claim 52, wherein the mixed refrigerant further comprises at least one of Ne or He.

93. The refrigerant blend of claim 64, wherein the mixed refrigerant further comprises at least one of Ne or He.

94. The refrigerant blend of claim 66, wherein the mixed refrigerant further comprises at least one of Ne or He.

95. The refrigerant blend of claim 80, further comprising at least one gas selected from the group consisting of Ne and He.

96. The refrigerant blend of claim 85, wherein the mixed refrigerant further comprises at least one of Ne or He.

97. refrigerant blends not containing hcfc as in claim 1, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, said earlier blends comprising at least one flammable component.

98. refrigerant blends according to claim 97, wherein said earlier blends comprised a hydrocarbon.

99. refrigerant blends not containing hcfc as in claim 8, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, said earlier blends comprising at least one flammable component.

100. refrigerant blends according to claim 99, wherein said earlier blends comprised a hydrocarbon.

101. refrigerant blends not containing hcfc as in claim 15, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, said earlier blends comprising at least one flammable component.

102. refrigerant blends according to claim 101, wherein said earlier blends comprised a hydrocarbon.

103. refrigerant blends not containing hcfc as in claim 22, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, said earlier blends comprising at least one flammable component.

104. refrigerant blends according to claim 103, wherein said earlier blends comprised a hydrocarbon.

105. refrigerant blends not containing hcfc as in claim 29, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, said earlier blends comprising at least one flammable component.

106. refrigerant blends according to claim 105, wherein said earlier blends comprised a hydrocarbon.

107. refrigerant blends not containing hcfc as in claim 36, said blends operating as a replacement in a refrigeration system to provide substantially the same thermodynamic performance in said system as provided by earlier blends of components, said earlier blends comprising at least one flammable component.

108. refrigerant blends according to claim 107, wherein said earlier blends comprised a hydrocarbon.

109. refrigerant blends according to claim 1, and further comprising lubricating oil in a range of less than approximately 1% by weight.

110. refrigerant blends according to claim 109, wherein said oil comprises a POE type lubricating oil.

111. refrigerant blends according to claim 109, wherein said oil comprises a PAG type lubricating oil.

112. refrigerant blends according to claim 8, and further comprising lubricating oil in a range of less than approximately 1% by weight.

113. refrigerant blends according to claim 112, wherein said oil comprises a POE type lubricating oil.

114. refrigerant blends according to claim 112, wherein said oil comprises a PAG type lubricating oil.

115. refrigerant blends according to claim 15, and further comprising lubricating oil in a range of less than approximately 1% by weight.

116. refrigerant blends according to claim 115, wherein said oil comprises a POE type lubricating oil.

117. refrigerant blends according to claim 115, wherein said oil comprises a PAG type lubricating oil.

118. refrigerant blends according to claim 22, and further comprising lubricating oil in a range of less than approximately 1% by weight.

119. refrigerant blends according to claim 118, wherein said oil comprises a POE type lubricating oil.

120. refrigerant blends according to claim 118, wherein said oil comprises a PAG type lubricating oil.

121. refrigerant blends according to claim 29, and further comprising lubricating oil in a range of less than approximately 1% by weight.

122. refrigerant blends according to claim 121, wherein said oil comprises a POE type lubricating oil.

123. refrigerant blends according to claim 121, wherein said oil comprises a PAG type lubricating oil.

124. refrigerant blends according to claim 36, and further comprising lubricating oil in a range of less than approximately 1% by weight.

125. refrigerant blends according to claim 124, wherein said oil comprises a POE type lubricating oil.

126. refrigerant blends according to claim 124, wherein said oil comprises a PAG type lubricating oil.

127. The refrigerant blend of claim 48, comprising less than approximately 1 wt % of the lubricant oil.

128. The refrigerant blend of claim 127, wherein said oil comprises a POE type lubricating oil.

129. The refrigerant blend of claim 127, wherein said oil comprises a PAG type lubricating oil.

130. The method of claim 72, wherein the hcfc-free refrigerant blend comprises less than approximately 1 wt % of the lubricant oil.

131. The method of claim 130, wherein said oil comprises a POE type lubricating oil.

132. The method of claim 130, wherein said oil comprises a PAG type lubricating oil.

133. The refrigerant blend of claim 76, wherein the refrigerant blend comprises less than approximately 1 wt % of the lubricant oil.

134. The refrigerant blend of claim 76, wherein the lubricant oil comprises PAG-type lubricant oil.

135. refrigerant blends according to claim 1, wherein the mol percents are the mol percents in circulation through the compressor of the refrigeration system.

136. The refrigerant blend of claim 52, wherein the mixed refrigerant comprises not greater than 50.0 mol % of the r-23.

137. refrigerant blends not containing hcfc for use in a very low temperature refrigeration system, said refrigerant blends in mol percent comprising:

		Overall range
	Component	(mole %)
	Argon	4-36
	r-14	10-55
	total of r-170 and any r-23 in blend	10-50
	r-125	5-20
	r-236fa	7-40

!

138. refrigerant blends as in claim 137, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

139. refrigerant blends according to claim 137, and further comprising lubricating oil in a range of less than approximately 1% by weight.

140. refrigerant blends according to claim 139, wherein said oil comprises a POE type lubricating oil.

141. refrigerant blends according to claim 139, wherein said oil comprises a PAG type lubricating oil.

142. refrigerant blends not containing hcfc, for use in a very low temperature refrigeration system where the evaporator temperature is as low as 105 K, said refrigerant blends comprising:

		Range (%
	Ingredient Name	by mol)
1	At least one of neon (Ne) or	0.00-10.0
	helium (He)
2	At least one of argon (Ar) or	10.0-45.0
	nitrogen
3	r-14 (CF4)	20.0-50.0
4	total of r-170 (Ethane) and any r-23 (CHF3) in blend	10.0-30.0
5	r-125 (C2HF5)	8.0-15.0
6	r-134a	0.0-5.0
7	Other high boiling components:	0.0-3.0
	at least one of r-236fa,
	E-347, r-245fa, r-4112

!

143. refrigerant blends as in claim 142, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

144. refrigerant blends according to claim 142, and further comprising lubricating oil in a range of less than approximately 1% by weight.

145. refrigerant blends according to claim 144, wherein said oil comprises a POE type lubricating oil.

146. refrigerant blends according to claim 144, wherein said oil comprises a PAG type lubricating oil.

147. refrigerant blends not containing hcfc, for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 118 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mole)
1	At least one of argon (Ar) or	10.0-40.0
	nitrogen (N2)
2	r-14	20.0-50.0
3	total of r-170 and any r-23 in blend	10.0-40.0
4	r-125	0.0-35.0
5	r-134a	0.0-10.0
6	At least one of E-347, r-4112,	0.0-6.0
	r-236fa or r-245fa

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least some r-170 is present in the blend;

provided that at least one of E-347, r-4112, r-236fa or r-245fa is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

148. refrigerant blends as in claim 147, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

149. refrigerant blends according to claim 147, and further comprising lubricating oil in a range of less than approximately 1% by weight.

150. refrigerant blends according to claim 149, wherein said oil comprises a POE type lubricating oil.

151. refrigerant blends according to claim 149, wherein said oil comprises a PAG type lubricating oil.

152. refrigerant blends not containing hcfc, for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 130 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mole)
1	At least one of argon (Ar) or	2.0-40.0%
	nitrogen (N2)
2	r-14	10.0-50.0%
3	total of r-170 and any r-23 in blend	10.0-40.0%
4	r-125	0.0-40.0%
5	r-134a	0.0-15.0%
6	At least one of r-245fa, r-	0.0-10.0%
	236fa, E-347, or r-4112

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least some r-170 is present in the blend;

provided that at least one of r-245fa, r-236fa, E-347, or r-4112 is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

153. refrigerant blends as in claim 152, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

154. refrigerant blends according to claim 152, and further comprising lubricating oil in a range of less than approximately 1% by weight.

155. refrigerant blends according to claim 154, wherein said oil comprises a POE type lubricating oil.

156. refrigerant blends according to claim 154, wherein said oil comprises a PAG type lubricating oil.

157. refrigerant blends not containing hcfc, for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 140 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mole)
1	At least one of argon (Ar) or	2.0-40.0%
	nitrogen (N2)
2	r-14	10.0-50.0%
3	total of r-170 and any r-23 in blend	10.0-40.0%
4	r-125	0.0-30.0%
5	r-134a	0.0-15.0%
6	At least one of r-236fa, r-	0.0-10.0%
	245fa, E-347, or r-4112

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least some r-170 is present in the blend;

provided that at least one of r-236fa, r-245fa, E-347, or r-4112 is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

158. refrigerant blends as in claim 157, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

159. refrigerant blends according to claim 157, and further comprising lubricating oil in a range of less than approximately 1% by weight.

160. refrigerant blends according to claim 159, wherein said oil comprises a POE type lubricating oil.

161. refrigerant blends according to claim 159, wherein said oil comprises a PAG type lubricating oil.

162. refrigerant blends not containing hcfc, for use in a very low temperature refrigeration system with low temperature (evaporator) as low as 155 K, said refrigerant blends comprising:

	Ingredient Name	Range (% by mole)
1	At least one of argon (Ar) or	0.0-40.0%
	nitrogen (N2)
2	r-14	5.0-50.0%
3	total of r-170 and any r-23 in blend	5.0-40.0%
4	r-125	0.0-40.0%
5	r-134a	0.0-30.0%
6	At least one of r-236fa, or	0.0-30.0%
	r-245fa
7	At least one of E-347 or r-4112	0.0-20.0%

!

wherein the mol percents are the mol percents in circulation through the evaporator of the refrigeration system;

provided that at least some r-170 is present in the blend;

provided that at least one of r-236fa, r-245fa, E-347, or r-4112 is present in the blend;

and wherein the refrigerant blends operate to avoid freezeout in operation of the refrigeration system.

163. refrigerant blends as in claim 162, and further comprising lubricating oil in a range of approximately 1% to 10% by weight, said oil being one of POE type and PAG type.

164. refrigerant blends according to claim 162, and further comprising lubricating oil in a range of less than approximately 1% by weight.

165. refrigerant blends according to claim 164, wherein said oil comprises a POE type lubricating oil.

166. refrigerant blends according to claim 164, wherein said oil comprises a PAG type lubricating oil.

167. A refrigerant blend free of hcfc containing a mixed refrigerant comprising:

at least one of Ar or N₂;

r-14;

r-125;

r-170; and

at least one of r-236fa, r-245fa, E-347, or r-4112.

168. The refrigerant blend of claim 167, wherein the mixed refrigerant comprises not greater than 40.0 mol % of a total of r-170 and any r-23 present in the blend.

169. The refrigerant blend of claim 167, wherein the mixed refrigerant comprises not greater than 50.0 mol % of a total of r-170 and any r-23 present in the blend.

170. A method of refrigerating, the method comprising:

using an hcfc-free refrigerant blend in a refrigeration system, the hcfc-free refrigeration blend containing a mixed refrigerant comprising:

at least one of Ar or N₂;

r-14;

r-125;

r-170; and

at least one of r-236fa, r-245fa, E-347, or r-4112; and

cooling an evaporator of the refrigeration system.

171. The method of claim 170, wherein the hcfc-free refrigerant blend further comprises lubricant oil.

172. The method of claim 171, wherein the hcfc-free refrigerant blend comprises approximately 1 wt % to 10 wt % of the lubricant oil.

173. The method of claim 171, wherein the lubricant oil comprises POE-type lubricant oil.

174. The method of claim 171, wherein the lubricant oil comprises PAG-type lubricant oil.

175. A refrigerant blend free of hcfc comprising (i) a mixed refrigerant comprising r-170 and at least one of r-236fa and r-245fa, and (ii) lubricant oil, wherein the refrigerant blend has a freezing temperature not greater than 150.0K.

176. A refrigerant blend according to claim 175, further comprising r-23.

177. A refrigerant blend free of hcfc containing a mixed refrigerant comprising:

at least one of Ar or N₂;

r-14;

r-170; and

r-125.

178. A refrigerant blend free of hcfc containing a mixed refrigerant comprising:

r-14;

r-125;

r-170; and

at least one of r-236fa, r-245fa, E-347, or r-4112.