Abstract: A fluid flow circuit intended for use with heat pumps having a flow control valve comprising a pair of restrictor assemblies positioned in opposed relationship. The first restrictor assembly provides for restricted flow in a first direction and unrestricted flow in the opposed and second direction. The second restrictor assembly provides for restricted flow in the second direction and unrestricted flow in the first and opposed direction.

Abstract: A evaporator for use in a refrigerating cycle in an air conditioning apparatus for a vehicle. The evaporator is provided with a heat exchanger and an evaporator. The heat exchanger has an inlet passageway for leading the refrigerant from the condenser to the evaporator, and an outlet passageway for leading the refrigerant from the evaporator to the compressor. A heat exchange between the inlet refrigerant and the outlet refrigerant at the heat exchanger part takes place, so that a combined gas-liquid state refrigerant is introduced into the outlet passageway of the heat exchanger from the evaporator, whereby a superheating state of the refrigerant is generated in the outlet passageway, and a result, no superheating action occurs in the evaporator, and thus the refrigerant in the evaporator is kept at a constant temperature, whereby the cooling efficiency of the evaporator is increased.

Abstract: A refrigerant shunt comprising an approximately cylindrical shunt portion which is provided at its one end with an inlet portion for forming a throttle, and at its other end with a collision wall for changing the flowing direction from the inlet portion, a plurality of output pipes which are radially spliced with the above described shunt portion peripheral wall, so that the vapor phase and the liquid phase of the refrigerant flowing into the inlet portion are uniformly mixed and also, are equally branched in flowing.

Abstract: Inefficiencies in an evaporator for a refrigerant in a refrigeration or air-conditioning system may be avoided in an evaporator having a plurality of tubes (18) in fluid and geometrical parallel through which the refrigerant may pass by providing a refrigerant distributor between an inlet (26) and the tubes (18) which includes an orifice (86) connected to the inlet (26) for directing a stream of refrigerant toward a flat impingement surface (102) from which it is disbursed to a plurality of receiver passages (34) angularly spaced about the periphery of the impingement surface (102) and respectively connected by a fluid passage (38, 44, 50) to an associated one of the tubes (18).

Abstract: A refrigeration expansion valve meters the flow of refrigerant therethrough through a flexible orifice that varies in cross sectional area as a function of the pressure differential across the valve. The flexible orifice is provided in a tubular elastomeric element that is supported at opposite ends by rigid support means. A rigid spacer means is provided for engaging the support means to prevent the pressure differential of the refrigeration system from exerting an axial force on the flexible flow metering element.

Abstract: A refrigerant expansion device including a body having a flow passage extending therethrough which may pass refrigerant in either direction. A piston is slideably mounted in the flow passage for movement between a first position and a second position in response to the direction of refrigerant flow through the flow passage. The piston has a metering port extending therethrough for metering the flow of refrigerant when the piston is moved to the first position responsive to the flow of refrigerant in one direction through the metering device. The piston also includes at least one flow channel substantially parallel to the metering port for passing a substantially unrestricted flow of refrigerant when the piston is moved away from the first position in the direction of the second position responsive to the flow of refrigerant in the opposite direction. Means are provided for moving the piston, against the flow of refrigerant in the one direction away from the first position.

Abstract: A refrigerant expansion valve meters the flow of refrigerant therethrough through a flexible orifice that increases in cross sectional area as the pressure differential across the valve increases.

Abstract: A new method and apparatus are provided for sensing refrigerant temperatures in refrigerator systems, and for preventing underloading of the coil, or of any of the coils in a plurality of refrigerator evaporator circuit coils connected in parallel. The usual thermostatically controlled refrigerant flow control valve is controlled by a thermostatic sensor to ensure a predetermined minimum amount of superheat, usually about 5.5.degree. C. (10.degree. F.). To avoid underloading the refrigerant is rendered thoroughly turbulent and mixed, and in the multi-coil evaporator the flows from all of the coils are similarly thoroughly turbulated and mixed, by a turbulating and/or mixing device that intercepts the entire refrigerant flow just before the sensing of the superheat, thus ensuring that the temperature is accurately measured; in the multi-circuit coil system the device averages the temperatures of all the flows. Different turbulator/mixer devices are described and two or more such devices may be used in series.

Abstract: A refrigeration expansion valve meters the flow of refrigerant therethrough through a flexible orifice that varies in cross-sectional area as a function of the pressure differential across the valve.

Abstract: An improved evaporator system for refrigeration systems, especially in environments where available space is restricted, the improvement including an inlet manifold disposed between an evaporator coil, which has a plurality of evaporator tubes, and a refrigerant expansion device. The inlet manifold is structured for more uniformly consistent and homogeneous composition of refrigerant received from the expansion device and delivered by the inlet manifold into each evaporator tube. The inlet manifold includes an elongated, endless refrigerant path through which refrigerant received from the expansion device circulates. The passageway has an elongated first portion spaced apart from, and generally coextensive with, an elongated second portion. Each of a plurality of inlet manifold outlets disposed in the first portion are connected to one of the plurality of the evaporator tubes.

Abstract: A porous coated enhanced evaporator tube and a method for producing the tube. The porous coating of the tube is applied by arc spraying two dissimilar metals on a tube and then etching the tube so that only one of the metals is etched out, and a porous surface, having voids where the etched out metal is developed. The voids form subsurface channels which provide nucleate boiling sites.

Abstract: A tube-type heat exchanger has the tube ends substantially flush with the upper tube sheet and liquid is distributed to the tubes through distributor heads which are sealed and therefore provide gas cushions absorbing volume changes in the tubes.

Abstract: A cylindrical expansion valve is mounted in a tank portion of a laminate type evaporator formed by alternately laminating flat sheet tubes and heat transfer fins. With this arrangement, the structure of the evaporator is made compact as a whole, and a conventional piping work for connecting the evaporator body with a thermo-sensing cylinder is eliminated, thereby rendering the assembling operation easy.

Abstract: A single layer cover means is disposed over and spaced apart from a heating surface for diverting vapor to flow along the heating surface, the cover means having openings to permit vapor to flow therethrough, the openings having an effective diameter equal to or greater than the distance between the heating surface and the cover means. The cover means induces an agitiating effect across the heating surface to enhance the heat transfer performance instead of forming nucleation sites. A plurality of spacer members is disposed at intervals between the heating surface and the cover means.

Abstract: In the tube (41) of a tube assembly of a crystallization apparatus, an insert (43) is provided which increases the effective surface in the interior of the tube (41). The insert has subsequent different sections (45, 46, 47). Seen in direction of flow the effective surface per unit of length of a subsequent section (46, 47) is larger than the effective surface of the previous section (45, 46). Because the heat removal by the coolant is a limiting factor for the kinetics of crystallization, the amount of crystals produced per unit of length of the tube is not substantially increased by the insert, but a smaller linear growth velocity is obtained at the surface of the crystals. This provides for better conditions for forming clean crystals. The inserts (343, 443 . . .

Abstract: A heat exchanger has a plurality of main flow passages 2 for cooling fluid. Each main flow passage has associated with it at least one narrow channel 10 defined by a surface of the main flow passage and an auxiliary surface on a separator plate 8. Relatively hot fluid flows over the separator plate 8 and heats the auxiliary surface such that bubbles formed in the channel are flattened by the surface opposite to the auxiliary surface and pressed against the auxiliary surface. The bubbles eventually pass through holes 12 in the channel 10 into the main flow passage 2 to rejoin the evaporating liquid pool.

Abstract: A refrigerant expansion device such as a Joule-Thomson expander has a surface with grooves or recesses which capture contaminants that condense from the refrigerant flow in the device, thereby avoiding blockage of the device by the condensed contaminants.

Abstract: An integrated evaporator and thermal expansion valve assembly for use in a refrigeration system. An evaporator includes a housing defining an inlet header and an outlet header. A valve is mounted on the housing in communication with the inlet header for controlling the flow of refrigerant to the evaporator of the refrigeration system. A pressure and temperature resonsive sensing bulb assembly is mounted on the housing in communication with the outlet header for responding to the superheat temperature in the outlet header of the evaporator for opening the valve when the superheat temperature increases and for responding to the pressure in the refrigeration system for closing the valve when the pressure increases to offset a portion of the effect of the temperature response on the valve.

Abstract: In a heat transfer wall having a number of fine and elongate tunnels adjacent to each other with a minute distance under the surface thereof being in contact with liquid on the heat transfer wall, and a number of fine openings for communicating the tunnels to the outside thereof defined on ceilings of the tunnels along the longitudinal directions thereof with each minute distance, a tongue-like projection is provided which protrudes from an edge of the opening or vicinity of the opening across the opening 1 whereby a flow of fluid passing through the openings provided with the projections is controlled so that heat transfer performance characteristics are improved.

Abstract: A coupling mechanism is provided for coupling an expansion device in a liquid refrigerant line of a refrigeration system. The coupling mechanism permits the expansion device to be removably coupled to the liquid refrigerant line, thereby permitting the expansion device to be easily decoupled and recoupled to the liquid refrigerant line.

Abstract: A heat pump with high coefficient of performance. The heat pump includes a compressor (6), a condenser (2), and an evaporator (5). The condenser (2) is connected to a water accumulator (3). A pump (15) circulates the water from the accumulator and through the condenser (2). The evaporator (5) is connected to a heat medium of a suitable kind with which heat exchange takes place. The evaporator includes a plurality of relatively short tubes (22) connected in parallel. Each tube at the lower end thereof includes separation means for oil, which is directed via a separate duct (26) to a separate oil inlet of the compressor (16). The tubes of the evaporator includes restrictions (22b) spaced along the length of the tubes. The restrictions are accomplished by the tubes being compressed while rotated. The rotations are preferably in different directions in adjacent compressions.

Abstract: In a perforated heat conductive surface structure having voids under an outer surface and openings in the outer surface, in order to obtain a high performance in particular at a low pressure and low temperature region, there is provided a heat transfer wall in which a thickness of a wall at a ceiling of each void and a length of a passage of the respective openings are increased in predetermined ranges.

Abstract: In a heat transfer wall provided with a plurality of cells and restricted holes, the cells are formed in a plurality of laminated layers in a direction from an outer surface of the heat transfer wall to an inside thereof, and the cells of the upper and lower layers and the outside of the outer surface are communicated to one another through the holes.

Abstract: Disclosed is an evaporator, particularly for air conditioning installations in automotive vehicles, comprising an evaporator block including several evaporator tubes and coolant supply means. The coolant supply means comprise an expansion valve, a feed tube and a manifold from which the evaporator tubes extend. A calming line segment for the coolant is arranged within the manifold. A distributing space connected with the calming segment is located adjacent to the calming segment. Means are provided for deflecting the coolant between the calming segment and the distributor space.

Abstract: A heat exchanger includes a plurality of hollow panels arranged in a stack with fins interspersed therebetween and each having a fluid passageway therein and an upper header and a lower header at opposite sides of the fluid passageway. An end plate is applied to at least one end of the stack and formed with an inlet opening and an outlet opening in nearby positions which communicate to a fluid circulation path defined in the stack by the fluid passageways and the upper and lower headers of the hollow panels. An inlet and outer manifold block is mounted on the end plate for fluidly communicating the inlet opening of the end plate to an inlet conduit and the outlet opening to an outlet conduit.

Abstract: The publication relates to means for cooling a body, comprising at least a tube through which a liquid coolant is flowing in order to remove heat away from the at least one tube and its surroundings. The tube(s) houses an internally arranged hose having a wall thickness, permeability and/or porousity and a quality which corresponds to the heat energy to be removed from the tube(s) and/or it surroundings. The hose has preferably an outer diameter which corresponds substantially to the internal diameter of the tube(s) and the hose is formed of a texture of a flexible material such as for example textile or fiberglass. The hose may be fastened to the tube at its inlet end.

Abstract: Disclosed is a heat exchanger comprising a plurality of parallel tubes and a plurality of ribs transverse to the tubes, and at least one connecting tank into which the tubes open. To obtain with simple and cost effectively produced means a uniform distribution of the fluid flowing through the heat exchanger over the heat exchanger tubes, the connecting tank has a chamber with a circular cross section and in the connecting tank a distributor installation is arranged which comprises a helical profiled body having an approximately stellate cross section which sealingly abuts with its ribs against the wall of the chamber. The partitions form a plurality of helical channels with one open and one closed end. An orifice is provided in the area of each channel for the passage of the fluid from the connecting tank into the tubes of the heat exchanger.

Abstract: A falling film evaporation type heat exchanger of the shell-tube type which includes an outer shell or main body portion and a plurality of individual heat transfer tubes disposed therein, with the heat transfer tubes extending substantially in a vertical direction. A liquid refrigerant is caused to freely fall from upper portions of the heat transfer tubes along the outer peripheral surfaces of the tubes and the evaporation of the thin refrigerant film, formed on the outer peripheral surface of the heat transfer tubes effects the transfer.

Abstract: A plate type evaporator comprising a plurality of vertically extending plate elements assembled face-to-face to define therebetween alternate channels for a heating medium and for a liquid to be evaporated. In order to accelerate the nuclear boiling of the liquid in the liquid channels, the heat transfer surface of each plate element has a plurality of vertically extending transversely spaced ridges projecting toward the associated liquid channel, such ridges being in contact with the heat transfer surface of the opposed plate element to provide areas of contact assisting in the evolution of vapor bubbles and divide the liquid channel into narrow sections assisting in the generation of vapor, such sections also assuring that even in deeper places in the liquid channel, vapor bubbles will be generated without yielding to the liquid pressure; alternatively, each plate element has a porous layer formed on its heat transfer surface facing the liquid channel.

Abstract: A fluid pressure reducing device having a core provided with a peripheral spiral groove and a pipe receiving the core. The portion of the pipe receiving the core is radially contracted so that the ridges of the spiral groove of the core intrude into the inner peripheral surface of the pipe, thereby to form a spiral passage between the pipe and the core. The pressure of a fluid is reduced as the latter flows through the spiral passage. This fluid pressure reducing device is easy to produce and permits an easy fine adjustment of the flow resistance.

Abstract: A method for promoting a boiling heat transfer by applying an electric field to a heat exchange medium, comprises making the relaxation time of an electric charge of a heat exchange medium used equal to or smaller than the characteristic time with respect to motion of bubbles generated by the heat transfer surface in the heat exchange medium to maximize the maximum boiling heat flux.

Abstract: A plate type evaporator comprising a plurality of vertically extending plate elements assembled face-to-face to define therebetween alternate channels for a heating medium and for a liquid to be evaporated. The plate elements have porous layers formed on their opposed heat transfer surfaces functioning as the channels for the liquid to be evaporated. The porous layers are utilized as nuclear boiling accelerating members to improve the capability of evaporating liquid on the boiling heat transfer surfaces.

Abstract: An annular capillary structure is disclosed for tubes of heat exchangers. The capillary structure comprises a series of individual, smooth, rectilinear fibers arranged parallel to the axis of a tube. The fibers are regularly positioned in annular spaces along the inner wall of the tubes. Helical springs or a layer of spring wires urges the fibers into contact with the inner wall of the tube. According to a preferred method of making the structure, a layer of spring steel wires are coiled on a mandrel and a layer of fibers is laid longitudinally thereon. The layer pass through an extruder head and are introduced into the tubular element which has just been extruded.

Abstract: A variable capacity refrigeration system and a fluid flow control device particularly well suited for use therewith. The fluid flow control device includes a body, a Belleville spring, and a plug. The body defines a fluid flow passage, and the plug is secured therewithin. The Belleville spring is positioned within the fluid flow passage and includes an inside edge defining a radially extending spring port for conducting fluid through the spring. The Belleville spring has a normal position, where the inside edge of the spring engages the plug to close the spring port, and an overcenter position, where the inside edge of the spring is spaced from the plug to allow fluid flow through the spring port.

Abstract: A vapor compression cycle device is provided using two capillaries to maximize efficiency benefits due to capillary flowrate regulation thus permitting the working fluid flowrate to depend on the level of liquid working fluid accumulated at the condenser.

Abstract: A vapor compression cycle device is provided which incorporates a first expansion device, a second expansion device with inlet positioned upstream from said first expansion device and means to transfer heat from the working fluid liquid flowing through said first expansion device to the expanded working fluid flowing through said second expansion device so as to maximize efficiency benefits due to flowrate regulation thus permitting the working fluid flowrate to depend on the level of liquid working fluid accumulated at the condenser.

Abstract: The thermosiphon is improved by providing the condenser section on the outer wall thereof with a heat storage section and further providing the condenser section in the lower portion thereof and adjacently to the heat storage section with a fluid reservoir for receiving the working fluid which has been condensed in the condenser section. In this thermosiphon, the working fluid which has been vaporized by the absorbed heat is condensed on the inner wall of the condenser section with liberation of part of its heat to the exterior of the thermosiphon. The remainder of the heat is accumulated in the heat storage section.

Abstract: A silicon substrate adapted for large scale integrated electronic circuits upon a lower surface has its upper surface coated with a highly porous heat sink film. The film is composed of a porous metal, preferably aluminum, formed by vacuum deposition (evaporation or sputtering) at a high pressure of an inactive gas. The gas can have a pressure of from about 0.5-100 millitorr, and a suitable gas is argon. A porous aluminum film with interconnected nucleation sites which are in the form of reservoir type cavities is manufactured on a silicon surface. The cavities tend to trap vapor of a liquid coolant in contact with the thin film contained in a package enclosing the substrate and its integrated circuit. Cooling fins can be used to cool the coolant.

Abstract: A distributor for feeding the liquid-vapor mixture of refrigerant from the expansion valve to the core elements of an evaporator of an air conditioning system to provide equal distribution of both the liquid and vapor components. The distributor involves either a single header with separate orifices for the liquid and vapor in each core element or a pair of distribution headers to carry the separated component phases from a separator with an orifice for each phase in each core element where the phases would be recombined to pass through the core elements to a common outlet.

Abstract: A heat exchange surface having nucleate boiling cavities defined by subsurface cavities in combination with a thin porous coating. A preferred embodiment of the heat exchange surface includes a plurality of helical fins formed on the outer surface of a metallic tube, the tips of which are deformed by rolling to define gaps opening into fin cavities between adjacent fins. A porous open-celled coating flame-sprayed on the deformed portion of the fins substantially bridges these gaps, except at random open points caused by the inherent porosity of the coating. These openings in the porous coating in combination with the fin cavities provide nucleate boiling sites which promote efficient heat transfer for boiling a liquid.

Abstract: A heat transfer surface for boiling liquid refrigerant 11 and its equivalents and method for producing the surface. The surface comprises a porous, open-cell coating at least 15 mils thick, of oxidized metallic particles which are flame-sprayed onto a metal substrate. This surface includes a substantial number of nucleate boiling cavities having an equivalent radius in the range of 1.5 to 4 mils, which are the result of one or more of the following conditions in the flame-spraying process: (1) The flame-spraying nozzle is oriented so that the metallic particles impact the metal substrate at an angle in the range of 30.degree. to 75.degree.; (2) The metal substrate is preheated to a temperature which is at least 600.degree. F., but below the melting point of the substrate; and (3) The flame-spraying apparatus is positioned such that the metallic particles travel from 3 to 6 inches before impacting the substrate.

Abstract: A refrigeration system for use in air conditioner for automobiles. The refrigeration system has a pressure reducing device disposed between a condenser and an evaporator and adapted for permitting the refrigerant to make an adiabatic expansion therethrough. The pressure reducing device includes a flow restricting and resisting means such as an orifice and a flow resisting means disposed at the upstream side of the flow restricting and resisting means. The flow resisting means are adapted to impart a resistance to the flow of refrigerant and may be constituted by a capillary tube or a constant-pressure-differential valve. Because of the resistance imparted by the flow resisting means, the dryness factor of the refrigerant at the inlet to the flow restricting and resisting means is maintained between 0 and 0.1, so that the flow rate of the refrigerant is largely affected by the characteristic of the flow restricting and resisting means.

Abstract: The invention is concerned with a heat transfer tube for use in boiling type heat exchangers, having an excellent heat transfer performance. More specifically, the invention relates to a surface condition of the heat transfer tube for improving the heat transfer performance and a method of producing the tube easily, especially a method for processing the surface condition efficiently and advantageously from an industrial point of view. The essential feature of the invention resides in a provision of a surface condition for promoting the boiling which consists of annular or spiral cavities extending along the tube surface in the circumferential direction of the latter, as well as narrow gaps extending along the cavities so as to allow the cavities to communicate the outside space. If necessary, spiral or annular fins may be provided on the tube surface, so as to improve the boiling performance at the outside of the tube.

Abstract: Recovery of substantially all of the work associated with the expansion of a multi-component working fluid mixture in a vapor compression cycle device is enabled by conveying working fluid in a liquid phase from a condenser to a coldest portion of an evaporator assembly in a countercurrent heat exchange relationship with fluid flowing through the evaporator assembly.

Abstract: A boiling heat transfer surface for heat transfer between a heat source and a coolant is provided. On the heat transfer surface contacting with a liquid coolant such as fluorinated hydrocarbon type liquid coolants, metallic particles having grain size of 60 mesh pass and 250 mesh nonpass (Japanese Industrial Standard sieve) are piled up and fixed by a metallic film on the heat transfer surface.

Abstract: A heat exchanger formed by concentric, spaced tubes defining a substantially annular chamber therebetween. There is an internal metallic fin comprising a strip of corrugated sheet metal extending spirally within the annular chamber with the adjacent turns of the spirally formed strip being spaced from each other to provide a spiral passageway between the side edges of adjacent turns. The metallic fin corrugated sheet metal strip bears a plurality of small apertures to significantly improve the boiling heat transfer coefficient.

Abstract: A compression refrigeration system having a compressor, a condenser, an evaporator, and a liquid refrigerant in which a capillary tube is positioned within an enclosure. The liquid refrigerant from the condenser is connected to the enclosure inlet and then flows to the inlet of the capillary tube and out of the capillary tube to the evaporator, whereby the refrigerant in the enclosure forms a heat exchange relationship with the exterior of the capillary tube for providing a self-regulating flow through the capillary tube. Improved charging of the system is provided by positioning the inlet to the capillary tube above the bottom of the enclosure and providing a refrigeration adding valve to the enclosure to insure that the enclosure is filled to a predetermined level in order to enter the capillary tube. Preferably, a reserve of liquid refrigerant is inserted into the enclosure above the capillary inlet for compensating for variations in density of the refrigerant.

Abstract: A conventional centrifuge refrigeration system is modified by connecting a capillary sized line between the expansion valve and the evaporator. This permits the expansion valve to be located at a point within the centrifuge remote from the rotor. This facilitates the easy removal of the expansion valve for repair and yet reduces icing of the expansion valve. Further, the system capacity may be improved by wrapping the capillary line about the suction line to effect subcooling of the refrigerant before it passes to the evaporator. This enhances system capacity.

Abstract: Improved nucleate boiling cavities are provided in a heat exchange surface by mechanically forming indentations on the heat transfer surface and then electrodepositing a metal on the pitted surface at a high current density followed by strengthening at lower current densities. Also described is a method of transferring heat from a warm fluid to a boiling liquid utilizing the improved nucleate boiling structure.

Abstract: A compressor, a condenser, an expansion valve and an evaporator are interconnected in a refrigeration circuit, the evaporator discharging the refrigerant toward the compressor as a two-phase flow which is a mixture of liquid particles and superheated vapor. A flow disturbing element is located in the circuit downstream from the evaporator and operates to give the two flowing phases an increased mutual relative speed.