Abstract: An integrated steam reformer/combustor assembly (42) is provided for use in a fuel processor (20) that supplies a steam/fuel feed mix (34) to be reformed in the assembly and a combustor feed (40) to be combusted in the assembly (42). The assembly (42) includes a housing (44,58) defining first and second axially extending, concentric annular passages in heat transfer relation to each other; a first convoluted fin (46) located in the first passage to direct the feed mix therethrough, the first convoluted fin coated with a catalyst that induces a desired reaction in the feed mix; and a second convoluted fin (50) located in the second passage to direct the combustor feed therethrough, the second convoluted fin coated with a catalyst that induces a desired reaction in the combustor feed.

Abstract: A combustor preheater (94) is provided for use in a fuel processor (20) to preheat a combustor feed (40) by transferring heat from a post water-gas shift reformate flow (32) to the combustor feed (40). The combustor preheater (94) includes a housing (92) defining first and second axially extending, concentric annular passages in heat transfer relation to each other; a first convoluted fin (96) located in the first passage to direct the post water-gas shift reformate flow (32) therethrough and a second convoluted fin (98) located in the second passage to direct the combustor feed therethrough.

Abstract: A fuel processing system is provided wherein heat is transferred from a reformate flow (32) downstream from a water-gas shift (38) to both a) a combustor feed flow (40) that is supplied to a combustor (25); and b) a water flow (26) that is supplied to a reformer feed mix (34) for a steam reformer (28).

Abstract: A recuperative heat exchanger (36) is provided for use in a fuel processor (20), the heat exchanger (36) transferring heat from a fluid flow (34) at one stage of a fuel processing operation to the fluid flow (32) at another stage of the fuel processing operation. The heat exchanger (36) includes a housing (56) defining first and second axially extending, concentric annular passages in heat transfer relation to each other; a first convoluted fin (70) located in the first passage to direct the fluid flow therethrough; and a second convoluted fin (72) located in the second passage to direct the fluid flow therethrough.

Abstract: An integrated fuel cell unit (10) includes an annular array (12) of fuel cell stacks (14), an annular cathode recuperator (20), an annular anode recuperator (22), a reformer (24), and an anode exhaust cooler (26), all integrated within a common housing structure (28).

Abstract: A heat exchanger is provided for transferring heat between a first fluid flow and a second fluid flow. The heat exchanger includes a first fluid flow path having a major dimension and a minor dimension and a second fluid flow including at least two flat tubes each having a major dimension and a minor dimension. Each of the flat tubes have at least two passes. Each tube has a transition region joining adjacent passes. Each transition region extends beyond the first fluid flow path major dimension.

Abstract: A heat exchanger (50) is provided for transferring heat between first and second fluids (52) and (54) having a maximum operating mass flow rate through the heat exchanger (50) and mass flow rates that are substantially proportional to each other. The heat exchanger (50) provides essentially constant outlet temperatures for the first and second fluids (52,54) for all of the flow rates within the operating spectrum of the heat exchanger (50) without the use of an active control system. The heat exchanger (50) is of particular use in the fuel processing system (36) of proton exchange membrane type fuel cell systems.

Abstract: Large thermal stresses are avoided and the fuel charge reduced in a vaporizer particularly suited for use in a reformer type fuel cell system and having a construction that includes alternating fuel/water flow path defining cells (68) and hot gas flow path cells (69) by providing heat transfer augmentation, such as a lanced and offset fin (120), only in that part of the gas flow path structure (69) adjacent the regions in the fuel/water flow path cells (68) where heating of the liquid fuel/water and vaporizing of the fuel/water where the mixture exists is a two phase material occurs and not in the area adjacent those parts of the fuel/water flow path structure (68) in which superheating of the vaporized fuel/water mixture is occurring.

Abstract: A vaporizer, a fuel cell system including the vaporizer, and a method of vaporizing fuel in a fuel cell system are disclosed. The fuel cell system includes a fuel reservoir (24) for storing a liquid fuel and a fuel cell (10) for consuming a fuel and generating electricity therefrom. A fuel vaporizer (28) is interposed between the fuel reservoir (24) and the fuel cell (10) for receiving liquid fuel and vaporizing it and delivering it ultimately to the fuel cell (10). The fuel vaporizer (28) includes a heat exchanger which includes a hot fluid inlet (65), a hot fluid outlet (67) and a core (50) interconnecting the inlet (65) and the outlet (68). The core (50) has alternating fuel flow structures (68) and hot fluid structures (69) with the fuel flow structures (68,69) having an inlet (56) and an outlet (58).

Abstract: An evaporative heat exchanger (10) is provided for the transfer of heat to a first fluid (30) from a second fluid (28) and a third fluid (22) to vaporize the first fluid (30). The heat exchanger (10) includes a core (40), a first flow path (60) in the core for the first fluid (30), a second flow path (66) in the core (40) for the second fluid (28), and a third flow path (68) in the core (40) for the third fluid (22). The core (40) includes a first section (42), a second section (44), and a third section (46), with the second section (44) connecting the first and third sections (42, 46). The first flow path (60) extends through all of the sections (42, 44, 46), the second flow path (66) extends through the first section (42), and the third flow path (68) extends through the third section (46).

Abstract: Rapid response to a fuel cell system of the type including a reformer (32) in response to a change in load is achieved in a system that includes a fuel tank (24), a water tank (20) and a source (42) of a fluid at an elevated temperature. A heat exchanger (28) is provided for vaporizing fuel and water and delivering the resulting vapor to the system reformer (32) and includes an inlet (64) and an outlet (66) for the fluid. It includes a plurality of fluid flow paths (100), (102), (104) extending between the inlet (64) and outlet (66) as well as a fuel inlet (56) and a fuel outlet (58) spaced therefrom. The fuel inlet (56) and outlet (58) are connected by a plurality of fuel flow paths (52) that are in heat exchange relation with the fluid flow paths (100), (102), (104) and the fuel water inlet (56) is located adjacent the upstream ends of the fluid flow paths (100), (102), (104).

Abstract: An evaporative heat exchanger (10) is provided for the transfer of heat to a first fluid (30) from a second fluid (28) and a third fluid (22) to vaporize the first fluid (30). The heat exchanger (10) includes a core (40), a first flow path (60) in the core for the first fluid (30), a second flow path (66) in the core (40) for the second fluid (28), and a third flow path (68) in the core (40) for the third fluid (22). The core (40) includes a first section (42), a second section (44), and a third section (46), with the second section (44) connecting the first and third sections (42, 46). The first flow path (60) extends through all of the sections (42, 44, 46), the second flow path (66) extends through the first section (42), and the third flow path (68) extends through the third section (46).

Abstract: A heat exchanger (50) is provided for transferring heat between first and second fluids (52) and (54) having a maximum operating mass flow rate through the heat exchanger (50) and mass flow rates that are substantially proportional to each other. The heat exchanger (50) provides essentially constant outlet temperatures for the first and second fluids (52,54) for all of the flow rates within the operating spectrum of the heat exchanger (50) without the use of an active control system. The heat exchanger (50) is of particular use in the fuel processing system (36) of proton exchange membrane type fuel cell systems.

Abstract: A vaporizer, a fuel cell system including the vaporizer, and a method of vaporizing fuel in a fuel cell system are disclosed. The fuel cell system includes a fuel reservoir (24) for storing a liquid fuel and a fuel cell (10) for consuming a fuel and generating electricity therefrom. A fuel vaporizer (28) is interposed between the fuel reservoir (24) and the fuel cell (10) for receiving liquid fuel and vaporizing it and delivering it ultimately to the fuel cell (10). The fuel vaporizer (28) includes a heat exchanger which includes a hot fluid inlet (65), a hot fluid outlet (67) and a core (50) interconnecting the inlet (65) and the outlet (68). The core (50) has alternating fuel flow structures (68) and hot fluid structures (69) with the fuel flow structures (68,69) having an inlet (56) and an outlet (58).

Abstract: Rapid response to a fuel cell system of the type including a reformer (32) in response to a change in load is achieved in a system that includes a fuel tank (24), a water tank (20) and a source (42) of a fluid at an elevated temperature. A heat exchanger (28) is provided for vaporizing fuel and water and delivering the resulting vapor to the system reformer (32) and includes an inlet (64) and an outlet (66) for the fluid. It includes a plurality of fluid flow paths (100), (102), (104) extending between the inlet (64) and outlet (66) as well as a fuel inlet (56) and a fuel outlet (58) spaced therefrom. The fuel inlet (56) and outlet (58) are connected by a plurality of fuel flow paths (52) that are in heat exchange relation with the fluid flow paths (100), (102), (104) and the fuel water inlet (56) is located adjacent the upstream ends of the fluid flow paths (100), (102), (104).

Abstract: A clamshell heat exchanger (10) is provided for use in a heating apparatus including a burner for producing hot combustion gas. The heat exchanger (10) defines a multi-pass flow passage (11) for the combustion gas and includes a first plate member (30) and a second plate member (32). The first plate member (30) has a first series of parallel ridges (36) and valleys (38a-b), with at least one of the valleys (38a) being deeper than other of the valleys (38b). The second plate member (32) faces the first plate member (30) and includes a second series of ridges (36) and valleys (38a-b) that are parallel to the first series of ridges (36) and valleys (38a-b), with at least one of the valleys (38a) of the second series being deeper than other of the valleys (38b) of the second series. A first pass (14, 16) of the multi-pass flow passage (11) is defined by a number N1 of the ridges (36) and valleys (38a-b) of the first and second series.

Abstract: Distribution of liquid refrigerant in an evaporator having a pair of spaced headers (20), (22) and a plurality of tubes (24) extending between the headers (20), (22) to define a plurality of spaced refrigerant passages (42) is achieved through the use of at least one refrigerant inlet (30), (32), (34), (36) within one of the headers (20). The inlet has a first port (49) adapted to be connected to a source of refrigerant to be evaporated, and oppositely directed second and third ports (50), (52) connected to the first port (49). The second port (50) is directed away from one side (44) of the header (20) while the third port (54) is directed toward the side (44) of the header (20).

Abstract: An improved evaporator or evaporator/condenser for use in refrigeration or heat pump systems including first and second spaced, pressure resistant headers (10, 12); a plurality of elongated tubes (20) of flattened cross-section extending in parallel, spaced relation between and in fluid communication with the headers (10, 12) and serpentine fins (34) extending between and bonded to adjacent ones of the tubes (20). The tubes (20) and fins (34), between the headers (10, 12), define a non-planar configuration having an apex (80). A condensate trough (82) is aligned with and opens towards the apex (80) to receive condensate dripping therefrom.

Abstract: An improved heat exchanger for exchanging heat between the ambient and a refrigerant that may be in a liquid or vapor phase. The same includes a pair of spaced headers with one of the headers having a refrigerant inlet and the other of the headers having a refrigerant outlet. A heat exchanger tube extends between the headers and is in fluid communication with each of the headers. The tube defines a plurality of hydraulically parallel refrigerant flow paths between the headers and each of the refrigerant flow paths has a hydraulic diameter in the range of about 0.015 to about 0.07 inches.

Abstract: An improved evaporator or evaporator/condenser for use in refrigeration or heat pump systems including first and second spaced, pressure resistant headers (10, 12); a plurality of elongated tubes (20) of flattened cross-section extending in parallel, spaced relation between and in fluid communication with the headers (10, 12) and serpentine fins (34) extending between and bonded to adjacent ones of the tubes (20). The tubes (20) and fins (34), between the headers (10, 12), define a non-planar configuration having a laterally directed apex (80). A condensate trough (82) is aligned with and opens towards one of the headers (12) to receive condensate dripping therefrom.