An ice machine includes a plurality of cooling tubes with each cooling tube having an inner tube and an outer tube extending around the inner tube to define an annular cavity between the inner tube and the outer tube. When refrigerant flows through the annular cavity between the inner tube and the outer tube, water in the inner tube freezes. The ice machine may also include a shell defining an internal cavity through which the plurality of cooling tubes extend; a water source operably connected to a water pump to flow water through the inner tube; a refrigerant source operably connected to a refrigerant pump to flow refrigerant through the annular cavity; and a heater operably connected to the internal cavity of the shell to flow a heated fluid through the internal cavity and across the plurality of cooling tubes.

A heat exchanger has first and second manifold portions and an array of substantially-parallel heat-transfer tubes extending between the first and second manifold portions. Each heat-transfer tube has an outer surface and an inner surface defining a conduit. In a cross-sectional view, the outer surface of each heat-transfer tube can form a first shape that is non-circular, and the inner surface of heat-transfer tube can form a second shape different than the first shape. Alternatively or additionally, at least one of the first shape and the second shape lacks reflectional symmetry in the cross-sectional view. Methods for fabricating such heat exchangers are also provided.

A heat exchanger is provided. The heat exchanger (40) provides a first plurality of tubes (50) and a second plurality of flow passages (52) which furcate near one of the first (42) and second (44) manifolds into two or more furcated flow passages and subsequently converge to exit the heat exchanger. The plurality of furcated flow passages are intertwined, reducing the distance between flow passages (50,52) containing each fluid therebetween to improve thermal transfer. Further, the furcations create changes of direction of the fluid to re-establish new thermal boundary layers within the flow passages to further reduce resistance to thermal transfer.

A fluid heating system including: a pressure vessel shell com including prising a first inlet; a heat exchanger disposed in the pressure vessel shell, the heat exchanger including a second inlet and a second outlet, wherein the second inlet of the heat exchanger is connected to the first inlet of the pressure vessel shell; and an exhaust manifold disposed in the pressure vessel shell, the exhaust manifold including a third inlet and a third outlet, wherein the third inlet of the exhaust manifold is connected to the second outlet of the heat exchanger, wherein the third outlet of the exhaust manifold is outside of the pressure vessel shell, and wherein the exhaust manifold penetrates the pressure vessel shell.

A heat exchanger includes a header, a plurality of tubes, and a reinforcement member. The header has a face plate that defines a plurality of orifices, a top plate that extends away from an end of the face plate, and a projection that extends outward from the top plate. Each of the plurality of tubes extend into a respective one of the plurality of orifices. The reinforcement member has a backing plate that is secured to the top plate, a brace that extends from the backing plate and is secured to a first of the plurality of tubes, and a protrusion that extends outward from the backing plate. The protrusion engages the projection to restrict movement of the reinforcement member in a longitudinal direction relative to the tubes.

A tube bundle-type heat exchanger, to a tube base, and to a method for sealing same. Aspects of the invention relate to a tube base for a tube bundle-type heat exchanger. In particular, the tube base includes a stack of multiple tube base plates with at least one through-opening for receiving a respective tube of the tube bundle-type heat exchanger. The throughopening is sealed by at least one seal ring. Additional aspects relate to a tube bundle-type heat exchanger comprising such a tube base and to a method for sealing a tube bundle-type heat exchanger in particular in the region of the tube base.

A tube-to-header sealing system for a heat exchanger comprises a pair of mating header plates, each header plate having a wall with a plurality of openings therein and including a continuous depression along the circumference of each header plate opening which forms one-half of an O-ring groove. Each of a plurality of O-rings is positioned in each O-ring groove and the header plates are secured together such that the header plate plurality of openings are aligned and trap each of the plurality of O-rings in O-ring grooves. A plurality of spaced-apart tubes each having a tube end secured in an opening in the wall of the header to form a tube-to-header joint are expanded outwardly to provide sufficient O-ring deformation to obtain a seal. In service, the resiliency of the O-ring seal allows for expansion and contraction of the tubes without the build-up of high stresses at the tube-to-header joint.

A heat exchanger may include a first collecting tank and a second collecting tank. The first collecting tank may include a first collecting pipe having a first collecting pipe opening for letting in a fluid and a second collecting pipe having a second collecting pipe opening for discharging the fluid. The second collecting tank may be arranged opposite the first collecting tank and may include a third collecting pipe and a fourth collecting pipe. The heat exchanger may also include a plurality of heat exchanger pipes fluidically connecting the first collecting pipe to the third collecting pipe and the second collecting pipe to the fourth collecting pipe. The heat exchanger may also include a separating wall arranged in each of the first collecting pipe and the second collecting pipe respectively dividing each into a first pipe section and a second pipe section.

A heat exchanger includes a stacked body that is configured by tubes stacked in a stacking direction and a header tank. The header tank includes a plate header and a tank body. The tubes include longitudinal ends attached to the plate header. The plate header includes a tube insertion hole provided with a stopper. One of the longitudinal ends of the plurality of tubes is inserted into the tube insertion hole. The stopper sets a position of the one of the longitudinal ends in the tube insertion hole. The stopper is provided with the tube insertion hole, and has a width dimension that is smaller than both of a width dimension of the tube insertion hole and a width dimension of the one of the longitudinal ends of the plurality of tubes when viewed in the stacking direction.

In one instance, a multistage microchannel condenser is provided for use as an aspect of a heating, ventilating, and air conditioning (HVAC) system. The multistage microchannel condenser includes at least two pluralities of flat tubes having microchannels, each associated with a different refrigeration circuit, that are interspersed so that when only one refrigeration circuit is operational, the multistage microchannel condenser still does not have any substantial thermal dead spots. Manifolds are used on each end of the multistage microchannel condenser to fluidly couple members of the at least two pluralities of flat tubes such that the refrigerant in each refrigeration circuit remains separated while still using a majority of the area of the face of the multistage microchannel condenser. Other aspects are presented.