Combustion cell for a heating system

A method for heating water in a heating system, comprising the following steps:

• providing a fan assembly, a lid, a convex shaped burner, and a convex shaped distributor;
• providing a heat exchanger coil, the heat exchanger coil extending around a longitudinal axis to surround a combustion chamber and having a plurality of wraps including a first wrap proximal to the burner and a last wrap distal to the burner;
• providing a lid for closing a first end of the combustion chamber;
• providing the burner with a central perforated region and with a peripheral hole-free region;
• providing the distributor with a peripheral region provided with apertures and arranging the distributor upstream the burner, so that the peripheral region of the distributor faces the peripheral region of the burner;
• providing a flange connected to the lid and to the burner, wherein the flange has a receiving surface and accommodates the first wrap of the heat exchanger coil in direct contact thereto;
• circulating water in the heat exchanger coil;
• supplying a premix of combustible gas and air to the burner, through the distributor,
• wherein a feeding chamber is provided between the lid and the distributor and wherein a premixed air-gas flow is conveyed from the fan assembly to the feeding chamber, through a feeding duct delimited by the flange and by the lid.

A combustion cell for a heating system, comprising:

• a fan assembly configured to supply a premixed air-gas flow required for combustion;
• a combustion chamber extending along a longitudinal axis from a first end to a second end;
• a lid for closing the first end of the combustion chamber;
• a burner having a convex profile and including a central region and a peripheral region, wherein the central region is perforated whilst the peripheral region is hole-free;
• a distributor having a convex profile and including a peripheral region provided with apertures, the distributor being located upstream the burner to feed the premixed air-gas flow to the burner and being arranged so that the peripheral region of the distributor faces the peripheral region of the burner;
• a flange configured for connecting the lid to the burner;
• a heat exchanger coil arranged around the longitudinal axis to surround the combustion chamber and provided with a plurality of wraps including a first wrap proximal to the burner and a last wrap distal to the burner,
• wherein the flange provides a receiving surface accommodating the first wrap of the heat exchanger coil in direct contact thereto, wherein
• a minimum axial distance between the heat exchanger coil and the burner along the longitudinal axis varies, between a minimum value and a maximum value, and wherein at least one the of the following conditions is met:
• i) the minimum value of the minimum axial distance is less than 20 mm;
• ii) the maximum value of the minimum axial distance is less than 30 mm.

A combustion cell for a heating system, comprising:

• a fan assembly configured to supply a premixed air-gas flow required for combustion;
• a combustion chamber extending along a longitudinal axis from a first end to a second end;
• a lid for closing the first end of the combustion chamber;
• a burner having a convex profile and including a central region and a peripheral region, wherein the central region is perforated whilst the peripheral region is hole-free;
• a distributor having a convex profile and including a peripheral region provided with apertures, the distributor being located upstream the burner to feed the premixed air-gas flow to the burner and being arranged so that the peripheral region of the distributor faces the peripheral region of the burner;
• a flange configured for connecting the lid to the burner;
• a heat exchanger coil arranged around the longitudinal axis to surround the combustion chamber and provided with a plurality of wraps including a first wrap proximal to the burner and a last wrap distal to the burner,
• wherein the flange provides a receiving surface accommodating the first wrap of the heat exchanger coil in direct contact thereto, the combustion cell further comprising a feeding chamber defined between the lid and the distributor, wherein the flange includes an ear extending radially with respect to the longitudinal axis, for receiving the fan assembly connected thereto.

A combustion cell for a heating system, comprising:

• a fan assembly configured to supply a premixed air-gas flow required for combustion;
• a combustion chamber extending along a longitudinal axis from a first end to a second end;
• a lid for closing the first end of the combustion chamber;
• a burner having a convex profile and including a central region and a peripheral region, wherein the central region is perforated whilst the peripheral region is hole-free;
• a distributor having a convex profile and including a peripheral region provided with apertures, the distributor being located upstream the burner to feed the premixed air-gas flow to the burner and being arranged so that the peripheral region of the distributor faces the peripheral region of the burner;
• a flange configured for connecting the lid to the burner;
• a heat exchanger coil arranged around the longitudinal axis to surround the combustion chamber and provided with a plurality of wraps including a first wrap proximal to the burner and a last wrap distal to the burner,
• wherein the flange provides a receiving surface accommodating the first wrap of the heat exchanger coil in direct contact thereto, wherein the distributor includes a plurality of holes on its central region, having different dimensions from those of the peripheral region, and wherein the apertures of the peripheral region form at least 60% of the total area of the holes of the distributor.