A fuel-fired, forced draft water heater is provided with a specially designed burner structure and combustion product flow path that permit the heater to operate with improved fuel efficiency, lowered CO and NOx emissions, and an improved water heat input distribution along the vertical length of the heater. The water heater includes a vertically oriented tank with a vent plenum structure formed at the top end of the tank interior and having an outlet passage connectable to an external combustion product vent pipe. A submerged vertical burner tube extends downwardly from the vent plenum and has an open lower end extending into a submerged turn bowl disposed at the bottom end of the tank interior. Extending upwardly from the turn bowl within the tank interior are a plurality of vertical flue tubes that communicate the interiors of the turn bowl and the vent plenum. A vertically elongated perforated conical burner is disposed within the burner tube and is supplied with a throughflow of a pressurized fuel/air mixture that is ignited by an igniter mounted on the top end of the burner. During operation of the water heater, hot combustion products discharged from the conical burner are sequentially flowed downwardly through the burner tube into the submerged turn bowl, upwardly through the flue pipes into the vent plenum, and then outwardly through the vent plenum outlet passage.

Wet-base, down-fired water heater

A fuel-fired, forced draft, down-fired water heater is provided with an improved combustion product flow path that permits the heater to operate with improved fuel efficiency, lowered CO and NOx emissions, and an improved water heat input distribution along the vertical length of the heater. The water heater includes a vertically oriented tank with a vent plenum structure formed at the top end of the tank interior and having an outlet passage connectable to an external combustion product vent pipe. A centrally positioned submerged vertical burner tube extends downwardly from the vent plenum and has an open lower end extending into a submerged turn bowl disposed at the bottom end of the tank interior. Extending upwardly from the turn bowl within the tank interior, and symmetrically arranged about the centrally disposed burner tube, are a plurality of vertical flue tubes that communicate the interiors of the turn bowl and the vent plenum. A suitable fuel burner is disposed within the burner tube and is supplied with a throughflow of a pressurized fuel/air mixture which is ignited to create a downwardly directed flame and associated hot combustion products. During operation of the water heater, the hot combustion products are sequentially flowed downwardly through the burner tube into the submerged turn bowl, upwardly through the flue tubes into the vent plenum, and then outwardly through the vent plenum outlet passage.

The present invention relates to a method of controlling the temperature of hot water for using hot water at a low-flow rate in a hot water supply system. The hot water supply system includes: a flow sensor; a heat exchanger; a water tank, a temperature sensor; a controller having an input unit; and a pump that is disposed in a pipe line connecting a first diverging point formed at a pipe line for an outlet and a second diverging point formed at a pipe line for an inlet. The method includes: measuring the flow rate of water flowing into the hot water supply system, using the flow sensor; preheating-circulating the water in the hot water supply system through an internal circulation path connecting the first diverging point, the second diverging point, and the heat exchanger, using the pump, after the controller stops the combustion of the heating device when the measured flow rate is an operation flow rate of the water supply system or less; measuring the temperature of the water circulating, using the temperature sensor; and setting predetermined temperature above user set-temperature as preheating circulation-off temperature and predetermined temperature below the set temperature as preheating circulation-on temperature, and then starting operation of the heating device when the temperature measured by the temperature sensor is preheating circulation-on temperature or less and stopping the operation of the heating device when the measured temperature is the preheating circulation-off temperature or more, using the controller.

Method for controlling a hot water temperature in using low flux in hot water supply system

The top storage tank end wall of a down-fired water heater has a first circumferentially spaced series of circular openings formed therethrough and centered about the tank axis, and a second circumferentially spaced series of circular openings centered about the tank axis and spaced radially outwardly of the first series of openings. Vertically disposed within the tank is a circumferentially spaced series of hollow U-tube immersion heating members each having a first open upper end secured to one of the first series of openings, and a second open upper end secured to one of the second series of openings. Shot-type fuel burners extend downwardly into the second open upper tube ends and are supplied with gaseous fuel via a manifold ring positioned atop the water heater. Hot combustion gases from the burners are drawn through the U-tubes by a draft inducer fan having an inlet connected to the first open upper ends of the tubes. In an alternate embodiment of the water heater, air-driven power fuel burners are connected to the first open upper tube ends and are supplied with driving air through a manifold structure connected to the outlet of a supply air blower. Combustion gases forced out the second tube ends are collected in an exhaust manifold structure for venting to atmosphere.

Multiple U-tube down fired water heater

A gas water heater includes a power burner, a flue tube, an exhaust plenum, and a draft hood. The flue tube includes a portion that describes at least a 360° loop. Products of combustion are forced through the flue tube under the influence of the power burner, and enter the exhaust plenum. In the exhaust plenum, the pressure of the products of combustion drops such that the products of combustion flow into the draft hood substantially entirely under the influence of natural convection. In one embodiment, the power burner fires down into the flue tube through a side wall of the water heater, the loop of the flue tube is near the bottom of the water heater, and the plenum is in the top of the water heater.

Gas water heater

A condensing storage water heater system comprises an inverted burner at the upper end of a water tank or cylinder connected to a vertical flueway passing through the center of the vessel. A finned heat exchanger is arranged coaxially in the flueway and the primary circuit water flowing through the heat exchanger and the products of combustion pass through the heat exchanger system in countercurrent flow. The burner and/or primary circuit flow are controlled using at least one temperature measuring device located in the storage tank so that condensation will be achieved by the heat exchanger arranged in the flueway.

Storage water heater system

© Brennwert-Vorratswasserheizer mit einem an der Kopfseite eines Speicherbehalters (1) angeordneten Sturzbrenner (2), der am oberen Ende eines vertikal und konzentrisch durch den Speicherbehalter verlaufenden Abgasfuhrungsrohrs (3) angeschlossen ist. © condensing water heaters with a on the head side of a storage container (1) arranged reverberatory burner (2), which is connected at the upper end of a vertically and concentrically extending through the reservoir exhaust gas guide tube (3). Ein Warmetauscherprofil (4) mit sternformigem Querschnitt ist koaxial im Abgasfuhrungsrohr (3) angeordnet und hat eine Mittelbohrung, durch die der Ladekreislauf mit einer dem Abgasstrom (A) entgegengerichteten Brauchwasserstromung (B) gefuhrt ist. A heat exchange profile (4) with a star-shaped cross-section is arranged coaxially in the exhaust gas guide tube (3) and has a central bore, is guided through which the charging circuit with a the exhaust gas stream (A) directed opposite domestic water flow (B). Der Brenner (2) und/ oder der Volumenstrom durch den Ladekreis ist in Abhangigkeit von wenigstens einem im Speicherbehalter (1) angeordneten Temperaturfuhler (21, 22, 23) derart geregelt, das der Abgaswarmetauscher (3, 4) als Kondensationswarmetauscher wirkt. The burner (2) and / or the volume flow through the load circuit is arranged in dependence on at least the storage vessel (1) temperature sensor (21, 22, 23) controlled such that the exhaust gas heat exchanger (3, 4) acting as a condensation heat exchanger.

Horst Brunje

Papers

Storage water heater system

Water storage heating installation