The heat exchanger comprises at least one gas flow channel, at least one water flow channel, and a metal wall delimiting the gas flow channel from the water flow channel. The at least one water flow channel comprises a number of consecutive parallel straight segments. Two consecutive parallel straight segments are separated by a wall and by a U-turn comprising an upstream section and a downstream section. The upstream and the downstream sections are defined as the sections of the U-turn delimited on the one hand by the plane of the wall separating the two consecutive parallel straight segments; and on the other hand by the plane through the end section of the wall separating the two consecutive parallel straight segments, the plane which is parallel with the width direction of the water flow channel and which is perpendicular to the plane of the wall separating the two consecutive parallel straight segments. In at least two U-turns the upstream section has a volume that is at least 20% lower than the volume of the downstream section.

The heat exchanger comprises at least one gas flow channel, at least one water flow channel, and a metal wall delimiting the gas flow channel from the water flow channel. The at least one water flow channel comprises a number of consecutive parallel straight segments. Two consecutive parallel straight segments are separated by a wall and by a U-turn comprising an upstream section and a downstream section. The upstream and the downstream sections are defined as the sections of the U-turn delimited on the one hand by the plane of the wall separating the two consecutive parallel straight segments; and on the other hand by the plane through the end section of the wall separating the two consecutive parallel straight segments, the plane which is parallel with the width direction of the water flow channel and which is perpendicular to the plane of the wall separating the two consecutive parallel straight segments. In at least two U-turns the upstream section has a volume that is at least 20% lower than the volume of the downstream section.

A heat source device comprising: a combustion chamber (2) provided between a burner (31) and a heat exchanger (1); an inlet pipe (20) for allowing a fluid to be heated to flow in the heat exchanger (1); an outlet pipe (21) for allowing the fluid to be heated to flow out from the heat exchanger (1); and a winding pipe (27) wound around an outer surface of a peripheral wall of the combustion chamber (2), wherein either the inlet pipe (20) or the outlet pipe (21) has an orifice (91) for throttling a fluid flow path of the fluid to be heated flowing in the inlet pipe (20) or the outlet pipe (21).

A plate (1) for a heat exchange arrangement has a first heat transferring surface (A) with a protrusion (7) forming a continuous and closed ridge. This ridge divides said surface into a closed inner region (A1) and an outer region (A2). The inner region (A1) encloses a first inlet porthole (2) and a first outlet porthole (5) for a first medium. The outer region (A2) has a second inlet porthole (3) and a second outlet porthole (6) for the first medium. A heat exchange arrangement comprises a stack of first and second plates of the above type. The protrusions (7) on the first heat transferring surfaces (A) of said plates are connected to each other to separate first channels into first and second flow paths for the first medium. Each first flow path is configured to direct the first medium from a first inlet to a first outlet inside the inner region (A1) and each second flow path is configured to direct the first medium from a second inlet to a second outlet in the outer region (A2), said inlets and outlets being defined between said inlet and outlet portholes (2, 3 and 5, 6 respectively).

A plate (1) for a heat exchange arrangement has a first heat transferring surface (A) with a protrusion (7) forming a continuous and closed ridge. This ridge divides said surface into a closed inner region (A1) and an outer region (A2). The inner region (A1) encloses a first inlet porthole (2) and a first outlet porthole (5) for a first medium. The outer region (A2) has a second inlet porthole (3) and a second outlet porthole (6) for the first medium. A heat exchange arrangement comprises a stack of first and second plates of the above type. The protrusions (7) on the first heat transferring surfaces (A) of said plates are connected to each other to separate first channels into first and second flow paths for the first medium. Each first flow path is configured to direct the first medium from a first inlet to a first outlet inside the inner region (A1) and each second flow path is configured to direct the first medium from a second inlet to a second outlet in the outer region (A2), said inlets and outlets being defined between said inlet and outlet portholes (2, 3 and 5, 6 respectively).

The present subject matter includes: a heat exchange part having heating medium channels, through which heating medium flows, and combustion gas channels, through which combustion gas burned in a burner flows, adjacently disposed in alternation in the spaces between the plurality of plates; a first welding part in which the outer edges of a pair of plates forming the heating medium channel are welded together; a second welding part in which the plates forming the combustion gas channel, between the plates forming the heating medium channel, are welded to the outer edges of the plates forming the heating medium channel to form; and a guide part for guiding the welding material molten solution of the first welding part into moving to the second welding part.

The present subject matter includes: a heat exchange part having heating medium channels, through which heating medium flows, and combustion gas channels, through which combustion gas burned in a burner flows, adjacently disposed in alternation in the spaces between the plurality of plates; a first welding part in which the outer edges of a pair of plates forming the heating medium channel are welded together; a second welding part in which the plates forming the combustion gas channel, between the plates forming the heating medium channel, are welded to the outer edges of the plates forming the heating medium channel to form; and a guide part for guiding the welding material molten solution of the first welding part into moving to the second welding part.

An embodiment of the present subject matter includes a heat exchange part having heating medium channels, through which heating medium flows, and combustion gas channels, through which combustion gas burned in a burner flows, adjacently disposed in alternation in the spaces between the plurality of plates, wherein the heat exchange part surrounds the outer sides of a central combustion chamber space, a plurality of the heat exchange parts are provided in a stacked structure, and the flow direction of the heating medium is unidirectional only in a part of the heating medium channels from among the heating medium channels provided in each layer.

The present subject matter includes: heating medium channels, in the space in between a pair of plates facing each other, through which the heating medium flows; combustion gas channels, on the outer sides of the heating medium channels, through which combustion gas burned in a burner flows; and heating medium dispersion parts, having an opening part and a shutting part, on an inlet, through which the heating medium flows into the heating medium channel, and an outlet, through which the heating medium flows out from the heating medium channel.

A system and method for providing hot water to a point of use such as a shower. Waste warm water from said point of use passes through a heat exchanger, where it initially warms incoming mains water, typically to about 34 C. The initially warmed water is heated to its final temperature, typically about 42 C., in a smart boiler. The smart boiler, which typically has a volume of about 40 liters, comprises two chambers with a flexible barrier therebetween. Each chamber is separately heated as needed. Hot water is drawn from one of the two chambers; simultaneously, the other chamber fills with initially warmed water and is heated to its final temperature. When the volume of water in the chamber from which water is being drawn reaches a minimum, the system begins to fill that chamber and to draw water from the other one.