A heat transfer fin includes a fin body having a plate shape, a plurality of through-holes famed through the fin body and spaced apart from each other in a first direction, in which a heat exchange pipe is inserted into the plurality of through-holes and heating water flows along an empty space in the heat exchange pipe, and two outer body portions protruding outward from at least partial areas of opposite ends of the fin body with respect to the first direction. Each of the outer body portions includes a contact portion that makes contact with a heat-insulating pipe with a heat-insulating side plate therebetween and that has a shape corresponding to at least a partial area of an outer surface of the heat-insulating pipe through which the heating water flows and a separated portion spaced apart from the heat-insulating side plate to form a gap.

The plate-type heat exchanger includes blocks stacked on each other, each of the blocks including a heat exchanger body configured to exchange heat between a first fluid and a second fluid. A connection passage for the first fluid is formed between blocks adjacent to each other of the plurality of blocks, the connection passage allowing the outlet of one of the blocks adjacent to each other and the inlet of the other of the blocks adjacent to each other to communicate with each other, the first fluid in the blocks adjacent to each other having different flow directions between the blocks adjacent to each other, and a second connection passage is provided between at least one pair of blocks adjacent to each other among the plurality of blocks, the second connection passage being configured to cause the first fluid to flow to a position different from the connection passage.

A plate for a heat exchange arrangement for the exchange of heat between a first and a second medium. The plate has a first heat transferring surface in contact with the first medium and a second heat transferring surface in contact with the second medium. The plate includes an inlet porthole for the first medium; an inlet porthole for the second medium, and an outlet porthole for the first medium. The first heat transferring surface includes a protrusion forming at least one ridge arranged to divide the heat transfer surface into at least a first region in direct thermal contact with the inlet porthole for the second medium, and a second region not in direct thermal contact with the inlet porthole for the second medium. The second region substantially surrounds the first region. The inlet porthole for the first medium is arranged in the first region, while the outlet porthole for the first medium is arranged in the second region. Moreover, the at least one ridge forms at least one elongated transfer channel arranged to convey the first medium from the first region to the second region.

A plate heat exchanger includes a plurality of plates stacked so that a liquid flow passage is formed on the inside thereof, and a gas flow passage through which heating gas passes, the gas flow passage being formed between the plurality of plates and including a gas inflow opening portion and a gas outflow opening portion positioned on an opposite side to the gas inflow opening portion, wherein the gas outflow opening portion has a smaller opening area than the gas inflow opening portion. Thus, when the heating gas passes through the gas flow passage, even if the volumetric flow thereof decreases due to a reduction in temperature or condensation, a reduction in the flow velocity of the heating gas can be suppressed. Hence, a reduction in a heat transfer coefficient can be suppressed, leading to an improvement in heat transfer efficiency, and as a result, reductions in overall size, weight, and manufacturing cost can be achieved appropriately.

A hybrid heating system is disclosed. The hybrid heating system includes a compressor that is configured to compress refrigerant. The hybrid heating system further includes a first heat exchanger that is configured to adjust a temperature of water by exchanging heat between the water and refrigerant compressed by the compressor. The hybrid heating system further includes a second heat exchanger that is configured to evaporate refrigerant by exchanging heat exchange with exterior air. The hybrid heating system further includes a first boiler heat exchanger that is configured to increase a temperature of water using heat generated by combustion. The hybrid heating system further includes a second boiler heat exchanger that is configured to exchange heat between exhaust gas discharged from the first boiler heat exchanger and refrigerant flowing into the second heat exchanger.

A heat exchanger, comprising at least a double shell, wherein the lower portion of the inner space of the inner shell is filled with liquid phase change medium, and at least one coiler is provided in the upper portion. The heated fluid flows in the coiler. After the downstream side pipe of the coiler is pierced through the inner shell, at least one surrounding pipe is formed in the cavity between the double shells. The bottom heat exchange plate of heat exchanger of the inner shell is located above the heat source. The cavity between the two shells forms the flue gas passage. After bottom heat exchange plate of the inner shell is heated by the heat source, the flue gas rises from the bottom of perimeter of the inner shell along the flue gas passage and the heat is transferred to the heated fluid in the surrounding pipe. The heat device using the heat exchanger according to the present invention can significantly improve the efficiency of heat utilization.

A fluid heating system including: a pressure vessel; an assembly comprising: a heat exchanger core including a second inlet and a second outlet; a first conduit having a first end connected to the second inlet of the heat exchanger core and a second end disposed outside of the pressure vessel; a second conduit having a first end connected to the second outlet of the heat exchanger core and a second end disposed outside of the pressure vessel; and a blower in fluid connection with the first end of the first conduit, wherein the fluid heating system satisfies the condition that a Bulk Heat Flux between the first end of the first conduit and the first end of the second conduit is between 45 kW/m.sup.2 and 300 kW/m.sup.2, and wherein the Pressure Drop between the first conduit and the second conduit is between 3 kiloPascals and 30 kiloPascals.

A heat exchanger management system and a method of operating the heat exchanger management system. In one embodiment, the heat exchanger management system includes a memory and an electronic processor electrically connected to the memory and configured to operate one or more burners to transmit heat to a heat exchanger for a first period of time that deposits corrosive condensates on a passivation layer of the heat exchanger, deactivate the one or more burners for a second period of time, operate one or more blowers to move air across the heat exchanger at a temperature that evaporates the corrosive condensates on the passivation layer of the heat exchanger and increases an oxide thickness of the passivation layer on the heat exchanger, and reactivate the one or more burners after the second period of time.

A heat exchanger includes a tube expansion portion provided on a heat transfer tube such that an outer peripheral surface of the heat transfer tube is pressed against an inner peripheral surface of a first hole provided in a side wall portion of a case, and a first concave surface portion that is provided in a part of an outer surface of the tube expansion portion and forms a first gap, into which brazing material of a first brazed portion advances, between the outer surface of the tube expansion portion and the inner peripheral surface of the first hole. Thus, the attachment strength of the heat transfer tube can be improved by means of a simple configuration.

A latent-heat exchanger comprising an upper heat exchange unit in which a plurality of circulating-heating-water heat exchange units having a circulating-heating-water flow channel formed therein and a lower heat exchange unit disposed on the lower side of the upper heat exchange unit, in which a plurality of direct-water heat exchange units having a direct-water flow channel formed therein is provided.