A heat exchanger including a heat transfer fin (1) having a heat-transfer-tube insertion hole (10) through which a heat transfer tube (40) is inserted, and a brazing material holding portion (100) provided above the heat-transfer-tube insertion hole (10) to hold a brazing material (4), wherein when the heat transfer tube (40) is inserted through the heat-transfer-tube insertion hole (10), left and right non-contact portions (15), (16) where a circumferential edge of the heat-transfer-tube insertion hole (10) and an outer circumferential surface of the heat transfer tube (40) are not in contact with each other are separately formed on an upper circumferential edge of the heat-transfer-tube insertion hole (10), and a brazing material guiding portion (100) extending toward the outer circumferential surface of the heat transfer tube (40) is formed between the left and right non-contact portions (15), (16).

A combined heat and power plant includes a gasifier, a heat exchanger arranged to reduce the temperature of the raw synthesis gas formed in the gasifier by exchanging the heat of the raw synthesis gas into heating medium used for heating and forming cooled raw synthesis gas, a filtration unit for cleaning the cooled raw synthesis gas to form refined synthesis gas suitable as a fuel for an internal combustion engine, an internal combustion engine where the refined synthesis gas is burnt to produce mechanical power, ducts for connecting different parts of the plant to each other a raw gas burner arranged after the gasifier to burn the raw synthesis gas formed in the gasifier during the time when the refined synthesis gas is not utilized in the internal combustion engine. A method for treating raw synthesis gas a combined heat and power plant is also disclosed.

A boiler comprising an enclosure which forms a heating chamber which contains water to be heated and accommodates a firebox which forms a combustion chamber with a burner associated therewith which comprises a combustion head, arranged in the combustion chamber and connected to a supply duct, and provided with a premixer of combustion air and combustible gas which is interposed along the supply duct. The combustion chamber is connected to a stack for the evacuation of the combustion gases into the external environment, elements being further provided for generating a flow of a mixture of air and gas toward the combustion head; at least one duct being provided for conveying the combustion gases which connects the stack to the supply duct.

The present invention provides a boiler system, for example for use in heating a domestic hot water supply, and which is significantly more fuel efficient than existing boilers, the boiler system comprising a first reservoir and a second reservoir which together define a combustion enclosure, a storage tank positioned to define an upper wall or roof of the enclosure and being in fluid communication with the first water reservoir, a heat exchange tube located in the storage tank and being in fluid communication with the second water reservoir; and a burner arranged to directly heat atmospheric gases within the enclosure in order to indirectly heat the walls of the enclosure.

The present invention provides a boiler system, for example for use in heating a domestic hot water supply, and which is significantly more fuel efficient than existing boilers, the boiler system comprising a first reservoir and a second reservoir which together define a combustion enclosure, a storage tank positioned to define an upper wall or roof of the enclosure and being in fluid communication with the first water reservoir, a heat exchange tube located in the storage tank and being in fluid communication with the second water reservoir; and a burner arranged to directly heat atmospheric gases within the enclosure in order to indirectly heat the walls of the enclosure.

A heat exchanger includes front and back walls forming a flue gas space such that a fluid flowing through a channel formed in the front and back walls can exchange heat with flue gas in the flue gas space, in use. The front wall includes a lower portion extending along the back wall, and an upper portion extending upwardly from an upper end of the lower portion and outwardly away from the back wall to form a combustion space of a flammable gas between the upper portion and the back wall. A length of the upper portion along a longitudinal direction thereof is longer than a length of the lower portion along a longitudinal direction thereof.

A heat exchanger includes front and back walls forming a flue gas space such that a fluid flowing through a channel formed in the front and back walls can exchange heat with flue gas in the flue gas space, in use. The front wall includes a lower portion extending along the back wall, and an upper portion extending upwardly from an upper end of the lower portion and outwardly away from the back wall to form a combustion space of a flammable gas between the upper portion and the back wall. A length of the upper portion along a longitudinal direction thereof is longer than a length of the lower portion along a longitudinal direction thereof.

A heat exchanger including a heat transfer fin (1) having a heat-transfer-tube insertion hole (10) through which a heat transfer tube (40) is inserted, and a brazing material holding portion (100) provided above the heat-transfer-tube insertion hole (10) to hold a brazing material (4), wherein when the heat transfer tube (40) is inserted through the heat-transfer-tube insertion hole (10), left and right non-contact portions (15), (16) where a circumferential edge of the heat-transfer-tube insertion hole (10) and an outer circumferential surface of the heat transfer tube (40) are not in contact with each other are separately formed on an upper circumferential edge of the heat-transfer-tube insertion hole (10), and a brazing material guiding portion (100) extending toward the outer circumferential surface of the heat transfer tube (40) is formed between the left and right non-contact portions (15), (16).

The present invention provides a boiler system, for example for use in heating a domestic hot water supply, and which is significantly more fuel efficient than existing boilers, the boiler system comprising a first reservoir and a second reservoir which together defme a combustion enclosure, a storage tank positioned to defme an upper wall or roof of the enclosure and being in fluid communication with the first water reservoir, a heat exchange tube located in the storage tank and being in fluid communication with the second water reservoir; and a burner arranged to directly heat atmospheric gases within the enclosure in order to indirectly heat the walls of the enclosure.