US3892102A

US3892102A - Vuilleumier refrigerator hot cylinder burner head

Info

Publication number: US3892102A
Application number: US449182A
Authority: US
Inventors: Bruno S Leo
Original assignee: Hughes Aircraft Co
Current assignee: Raytheon Co
Priority date: 1974-03-07
Filing date: 1974-03-07
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01

Abstract

Vuilleumier refrigerator has its hot cylinder heated by a burner head. The burner head includes a heat transfer surface of concave configuration and rough surface in thermally conductive relationship to the hot volume.

Description

United States Patent Leo July 1, 1975 [54] VUILLEUMIER REFRIGERATOR HOT 2,484,392 10/1949 VanHeeckeren 62/6 CYLINDER BURNER HEAD $5 3, 27 8/1970 [75] Inventor; Bruno S. Leo, Santa Momca, Cahf. 3 742 719 7 973 Assignee: Hughes Aircraft p y, Culver 3,774,405 ll/l973 Leo 62/6 1 y Ca If Primary Examiner-Wtll1am J. Wye

[ Filfidi 1974 Attorney, Agent, or Firm-Allen A. Dicke. Jr.; W. H.

21 Appl. No.: 449,182 MacAlllsmr 57 ABSTRA T [52] US. Cl 62/6; 62/87 51 Int. Cl. F25]; 9/00 vmlleumler refrlgerawr has Its hot cylmder heated y 581 Field of Search 62/6 3 burner head- The burner head includes a heat transfer surface of concave configuration and rough sur- 5 Refu-ences Cited face in thermally conductive relationship to the hot UNITED STATES PATENTS 1.275,507 8/1918 Vuilleumier 62/6 3 C aims, 1 Drawing Figure VUILLEUMIER REFRIGERATOR HOT CYLINDER BURNER HEAD BACKGROUND This invention is directed to a cryogenic refrigerator operating on the Vuilleumier cycle and particularly to the heater structure for supplying the refrigerator power.

Vuilleumier cycle refrigerators are known. The original disclosure was in U.S. Pat. No. 1,275,507 by Rudolph Vuilleumier. That heat cycle has been developed and modernized into an efficient miniaturized cryogenic refrigerator. An example of that is shown in K. W. Cowans U.S. Pat. RE. No. 27,338. Particular mechanical structure of such a refrigerator is found in G. P. Lagodmos U.S. Pat. No. 3,742,719. Prior cryogenic refrigerators using this cycle have employed heating by using an electric resistance heater wrapped around the hot end of the hot cylinder. This is a convenient way of producing the necessary high temperatures, but, in some installations and under some circumstances, electric heating is less satisfactory than a fuel combustion situation. The present disclosure is directed to an efficient way of providing heat to the hot cylinder by fuel combustion.

SUMMARY In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to a Vuilleumier refrigerator hot cylinder burner head, and particularly structure which results in efficient heat transfer from fuel combustion products into the hot end of the hot cylinder. lt includes a shaped combustion surface of rough character for efficient combustion and heat transfer.

It is thus an object of this invention to provide a hot cylinder burner head structure for a Vuilleumier refrigerator which permits the combustion of gas and similar fuels for hot cylinder heating. It is a further object to provide a Vuilleumier refrigerator having a heating system which eliminates the need for electric heating. It is a further object to provide a hot cylinder heating structure which provides for efficient combustion and efficient heat transfer. It is a further object to provide a Vuilleumier hot cylinder heater which is economical of construction, and fuel consumption trouble free in use, and reliable in operation.

Other objects and advantages of this invention will become apparent from a study of the following portion of the specification, the claims and the attached drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS The single FIGURE of the drawings is substantially a central longitudinal section through a Vuilleumier refrigerator having a hot cylinder burner head in accordance with this invention.

DESCRIPTION The Vuilleumier refrigerator, including the burner head of this invention is generally indicated at 10. Vuilleumier refrigerator 10, has a hot cylinder 12, which contains hot displacer 14. Heat is added to head 16 of the hot cylinder to supply input power to the refrigerator. The refrigerator also has a cold cylinder 18 in which is located cold displacer 20. The cold end of cold cylinder 18 carries device 22 for which cryogenic renecessary insulation. 5

frigeration is suppliedby the refrigerator. Housing 28 has an insulating device, such as a Dewar to provide the Crankcase 24 contains crank '26. Connecting rods appropriately connect to both of the disp-Iacers to control them in proper cyclic relationship to operate the refrigerator on the Vuilleumier cycle. It should be noted that the warm end of both the hot and cold cylinders, which includes crankcase 24, is above ambient to permit heat rejection to atmosphere. Thus, the warm ends of both

regenerators

30 and 32, are connected with finned tubing, shown on the drawing, or are otherwise arranged so that the refrigerant gas at the warm ends of these generators can reject heat to the ambient. The refrigerator thus described is the one shown in K. W. Cowans U.S. Pat. RE. No. 27,338. Housing 34 embraces much of the refrigerator structure and contains fan 36 for moving air from left to right through housing 34 for cooling the warm section of the refrigerator.

Gas nozzle 44 is provided with a combustible gas under pressure. The gas is directed into the venture throat 46 to induce air into primary air inlet 48. The gas and primary air mixture passes into gas chamber 50 and passes through annular nozzle throat 52. Nozzle throat 52 is formed between cone 42 and collar 54. Collar 54 is adjustably mounted, as by being mounted on screwthreads as shown, so that the gap can be adjusted. On its way to the annular nozzle throat 52, the combustible gas passes through orifices 56. Orifices 56 have a sufficiently high velocity therethrough that the flame front cannot pass back into gas chamber 50. Thus, collar 54 basically holds the flame against the outside of cone 42. From the bottom of the cone, the flame and now principally hot gas of the products of combustion spread outward on the heat transfer surface 40 which is part of a sphere. The surface finish of heat transfer surface 40 is sufficiently rough, about 1000 microinches roughness height, to enhance heat transfer and maintain high transfer rates. Heat transfer surface 40 is formed on head 38, and head 38 may be an integral head on the hot cylinder. On the other hand, it may be a separate device which is attached by any convenient means, such as a screwthread; however, when there is a separate head it must lie in close thermal relationship to the hot cylinder. The resultant products of combustion preheat the incoming gas mixture and secondary air and then exhaust from gas openings 58 and 60 into the air stream passing out of refrigerator 10.

Secondary air is induced through secondary air inlet 62 and is discharged to the burning gas area through the nozzle embracing collar 54. Combustion takes place along surface 40 with the secondary air directly delivered. Throat 52 acts as the flame stop with orifices 56 providing secondary flame stop protection.

This invention having been described in its preferred embodiment, it is clear that it is susceptible to numerous modifications and embodiments within the ability of those skilled in the art and without the exercise of the faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.

I claim:

1. A Vuilleumier-type refrigerator comprising:

a hot cylinder having a head, a concave curved thermal heat transfer surface on said head, a solid cone extending from said curved heat transfer surface;

a fluid fuel burner formed around said cone so that combustion flame impinges along said cone and onto said curved heat transfer surface so that products of the combustion pass along said heat transfer surface so that heat is provided for the hot cylinder of the Vuilleumier refrigerator.

2. The refrigerator of claim 1 wherein a collar is positioned around said cone to form said noz zle as an annu- V combustion to said hot cylinder heat.

Claims

1. A Vuilleumier-type refrigerator comprising: a hot cylinder having a head, a concave curved thermal heat transfer surface on said head, a solid cone extending from said curved heat transfer surface; a fluid fuel burner formed around said cone so that combustion flame impinges along said cone and onto said curved heat transfer surface so that products of the combustion pass along said heat transfer surface so that heat is provided for the hot cylinder of the Vuilleumier refrigerator.

2. The refrigerator of claim 1 wherein a collar is positioned around said cone to form said nozzle as an annular nozzle.

3. The refrigerator of claim 1 wherein said curved heat transfer surface is rough to enhance heat transfer and maintain high heat transfer rates from products of combustion to said hot cylinder heat.