Hitachi, Ltd.

Babcock-Hitachi Kabushiki Kaisha

Babcock-Hitachi K.k.

Babcock-Hitachi Kabushiki

Hitachi Babcock Kabushiki-Kaisha

Kiyoshi Narato

Hironobu Kobayashi

Shigeru Azuhata

Norio Arashi

Tooru Inada

Kenichi Sohma

Tadayoshi Murakami

Masayuki Taniguchi

Hiroshi Miyadera

Michio Kuroda

Keizou Ohtsuka

Yoji Ishibashi

Shigeki Morita

Hirofumi Okazaki

Yukio Hishinuma

Akira Baba

Yoshitaka Takahashi

Tadahisa Masai

Yasuo Yoshii

Hideo Kikuchi

Sadahiko Niwa

Fumio Koda

Stephen M Masutani

Yasuo Iwai

Takashi Watanabe

Kazutoshi Higashiyama

Kenichi Souma

Toshikazu Tsumura

Kazuyuki Ito

Tomihisa Ishikawa

Satoshi Tsukahara

Tadashi Jimbo

Noriyuki Hayashi

Kunio Hodozuka

Shigekazu Nishimoto

Tsuyoshi Kohno

Tsuyoshi Kouno

Masao Masutani

Syoichi Sawahata

Keizo Ootsuka

Masaaki Shiga

Keizo Ohtsuka

Ken-ichi Sohma

Masakiyo Tanikawa

Kei Kawano

Tooru Inata

Isao Koyama

Tatsuzou Enomoto

Kenshi Kobayashi

To provide a pulverized coal burner capable of reducing the NOx concentration at the time of a low load, a pulverized coal burner includes a secondary air nozzle and a tertiary air nozzle concentrically positioned about the outer periphery of a fuel nozzle carrying a pulverized coal with a primary air, and two swirling flow generators are included at least one of these nozzles with a positional relation parallel to a flow of air. One of the swirling flow of the two swirling flow generators can be set strongly. And, under a condition of low air flow rate, air can be supplied from one swirling flow generator alone. Since the swirling strength of the combustion air can be increased, the concentration of NOx produced by the combustion of the pulverized coal can be reduced. Also, because the swirling strength at the time of low load can be increased, the NOx concentration can be reduced by keeping the pulverized coal flame stable.

Pulverized coal burner and method of using same

A pulverized coal combustion burner includes a pulverized coal nozzle, and secondary and tertiary air nozzles provided in concentric relation to the pulverized coal nozzle. A flame stabilizing ring is provided at an outlet end of the pulverized coal nozzle. A separation wall is provided within the pulverized coal nozzle to divide a passage in this nozzle into two passages. A pulverized coal/air mixture flows straight through the two passages, so that recirculation flows of the pulverized coal/air mixture are formed in proximity to the outlet end of the pulverized coal nozzle. As a result, the ignitability of the pulverized coal, as well as a combustion rate, is enhanced, thereby reducing the amount of discharge of NOx.

Pulverized coal combustion burner

A gas turbine combustor is capable of reducing NOx over a whole load range of a gas turbine. The combustor comprises two burner systems. It is possible to independently control a flow rate of combustion air supplied to a burner of the respective systems and a flow rate of bypass air jetted from through a bypass air port. The air supplied to the burners is mixed with fuel in a mixing chamber and then ejected into a combustion chamber so as to form a flame. The amount of bypass air is controlled in accordance with an operation load, a humidity of air and a heating value of fuel. It is therefore possible to prevent any blow off and reduce NOx over the whole load range of the gas turbine.

Gas turbine combustor and gas turbine generating apparatus

A gas turbine combustor of the pre-mixed combustion system in which the pre-mixed fuel and the air are combusted. The gas turbine combustor comprises main cylindrical nozzles provided in the end wall on the upstream side of a cylindrical combustion chamber, auxiliary nozzles formed to surround the main nozzles, a main pre-mixed gas supply for supplying a pre-mixed gas to the main nozzles, and an auxiliary pre-mixed gas supply for supplying a pre-mixed gas having an fuel/air ratio smaller than that of the main pre-mixed gas to the auxiliary nozzles, and wherein it is allowed to stably burn a lean pre-mixed gas having an fuel/air ratio of greater than 1 from a low-load condition through and up to a high-load condition of the gas turbine.

Gas turbine combustor of the completely premixed combustion type

In a combustor including a premixing type combustion burner which has an atomizer for ejecting a liquid fuel together with combustion air to atomize the liquid fuel, the atomizer is comprised of an inner shell to an inner peripheral surface of which the liquid fuel is supplied, an outer shell defining a passage for the combustion air running substantially straightly between the outer shell itself and an outer peripheral surface of the inner shell, and a swirling-flow guide plate for swirling the combustion air passed into the inner shell, while directing it in a downstream direction. The combustor further includes a resistor abruptly decreased in sectional area downstream and provided substantially downstream of the center of the swirling flow and in the vicinity of an outlet of the premixing type combustion burner for providing a resistance to a premixture ejected from the premixing type combustion burner.

Combustor and combustion apparatus

A burner for pulverized coal has a coal duct for pulverized coal and primary combustion air and a secondary combustion air duct such that the coal and primary air and secondary air mix outside the outlet nozzles of the duct in a mixing zone at which combustion occurs. Coal distribution means in the coal duct create, adjacent the outlet nozzle, at least one outer zone of flow spaced from the coal duct axis and at least one inner zone of flow nearer the coal duct axis. These are means for slowing flow in the outer zone relative to the flow in the inner zone, prior to the mixing zone. To achieve good mixing, and promote NO.sub.x reduction, the coal concentration in the outer zone is higher than in the inner zone. The slowing means may be radially inwardly projecting baffles.

Pulverized coal burner, pulverized coal boiler and method of burning

A low-NOx boiler comprises a burner for burning gaseous fuel, heat transfer pipes heating water by combustion heat of the burner to generate steam and having a passage through which water flows, a steam drum communicating with the heat transfer pipe and accumulating the steam from the heat transfer pipe, and an exhaust gas duct located in the furnace to exhaust combustion gas generated by combustion of gaseous fuel outside of the boiler. The boiler further comprises unburnt gas burner in the exhaust gas duct for burning unburnt content in the combustion gas flowing in the duct. The unburnt gas burner includes a nozzle for injecting premixture flow of fuel and combustion air and flame holding plate located near the downstream side of the outlet of the nozzle to interrupt the premixture flow to form a circulating flow on downstream side of the flame holding plate. As gaseous fuel and air are mixed in advance and a flame is formed, the flame length can be shortened. Furthermore, the flame holding plate enables to reduce NOx generated. Unburnt gas burner provided in the exhaust gas duct makes it possible to notably reduce the concentration of NOx discharged to the outside of the system.

Low NOx boiler

A gas turbine combustor comprises a combustion chamber, a premixing chamber in which hydrocarbon fuel and air are premixed, a nozzle with swirler for swirling and injecting the premixed fuel and air into the combustion chamber, to effect premixed combustion, and a fuel nozzle projecting into the combustion chamber and adapted to inject fuel at region wherein the premixed combustion is completed, so as to effect low air-ratio diffusion combustion thereby to produce reducing substance. NOx produced by the premixed combustion is reduced by reducing reaction with the reducing substances, so that the NOx concentration in the combustion gas is reduced. The combustor further includes an after-air ports on a peripheral wall defining the combustion chamber to effect combustion of unburnt substances.

Gas turbine combustor and a method of combustion thereby

A low NOx burning method and apparatus wherein a low air ratio flame burned with an amount of air less than an amount of air in a theoretical air ratio required for burning fuel perfectly is formed, and combustibles discharged from the low air ratio flame are burned at a trailing stream of the low air ratio flame while supplying air. The low air ratio flame is a premixing flame burned by premixing the fuel and air, and combustion of the premixing flames is maintained in the vicinity of the premixing flame. In this way, the generation of the NOx during the burning can be greatly decreased, and the required apparatus can be small-sized.

Low NOx burning method and low NOx burner apparatus

A spectroscope apparatus includes a device for separating light from an object to be measured into spectral components, a device for mixing spectral components which exists in a desired wavelength range, and a device for forming an image of the to-be-measured body of mixed light. The image obtained is very useful for observing the state of a combustion flame, the progress a photochemical reaction, the progress of a biochemical reaction, tissue in a cell, and the state of a flame for analyzing a solution which contains a metal ion by flame spectrophotometry. The apparatus provides accurate analytical information and makes possible precise control operations.

Spectroscope apparatus and reaction apparatus using the same

A low NOx burner comprises a pulverized coal nozzle for injecting a flow of a mixture of pulverized coal with primary air, a secondary air nozzle arranged externally of and coaxially with the pulverized coal nozzle, a tertiary air nozzle arranged externally of the secondary air nozzle and disposed coaxially with the pulverized coal nozzle, and a swirl flow generator for injecting secondary air and tertiary air as a respective swirl flow. Between the secondary air nozzle and the tertiary air nozzle, there is provided a spacer having such a thickness as to delay the mixing of the secondary air and the tertiary air and to form a swirl flow between the secondary air and the tertiary air.

Low NOx burner

A spectroscope apparatus includes means for separating light from an object to be measured into spectral components, means for mixing that part of the spectral components which exists in a desired wavelength range, and means for forming an image of the to-be-measured body of mixed light. The image thus obtained is very useful for observing the state of a combustion flame, the progress of photochemical reaction, the progress of biochemical reaction, a desired tissue in a cell, and the state of a flame for analyzing a solution which contains a metal ion, by flame spectrophotometery, that is, provides accurate information and makes possible a precise control operation.

An atomizer including a fuel supply passage for supplying a fuel, an atomizing medium supply passage for supplying an atomizing medium which is to be mixed with the fuel, a mixing chamber in communication with the fuel supply passage and the atomizing medium supply passage, and spray ports for spraying the fluid mixture consisting of the fuel and the atomizing medium from the mixing chamber. The fuel supply passage and the atomizing medium supply passages are communicated with the mixing chamber through a pre-mixing chamber having an annular cross-section defined by a large-diameter cylindrical surface and a small-diameter cylindrical surface. The fuel and the atomizing medium supplied from the fuel supply passage and the atomizing medium supply passage are pre-mixed the pre-mixing chamber. With this arrangement, it is possible to efficiently mix a slurry fuel and an atomizing medium, thus reducing the particle size of the atomized fuel particles and shortening the flame length. Thus, the atomizer of the invention is indispensable for the boilers which are intended for burning coal-water slurry. The invention makes it possible to form flames with reduced NOx generation and a high burning efficiency through combination between atomizer of the construction described above and a burner having a specific construction.

Atomizer and coal-water slurry fired boiler utilizing the same

A method of combusting a coal-water mixture fuel. The mixture is atomized into a conically-shaped primary pre-combustion chamber. Primary air is supplied, at a rate smaller than that required for complete burning of the mixture and in the form of a swirl about the axis of the jet of the atomized mixture, from the peripheral portion of the primary pre-combustion chamber into a secondary pre-combustion chamber connected to said primary pre-combustion chamber, thus forming a region of low pressure around the jet of the mixture. The region of low pressure serves to induce the atmosphere gas from the secondary pre-combustion chamber of higher temperature back into the primary pre-combustion chamber of a lower temperature, so that the water content of the mixture is evaporated and the mixture is ignited by the heat of the hot atmosphere gas. Then, the mixture is burnt in the secondary pre-combustion chamber in the presence of the remainder portion of the primary air, at a comparatively small air-to-ratio, so that a region of a reducing atmosphere is formed to suppress the generation of NOx. Then, secondary air is supplied, in the form of a swirl about the axis of the jet of the mixture and at a rate sufficient to completely burn the mixture, into the furnace connected to the secondary pre-combustion chamber, thus completely combusting the coal-water mixture.

Method of and apparatus for combusting coal-water mixture

A furnace system connected to a burner including a furnace for burning a fuel and air ejected from the burner into the furnace to produce a flame therein, and a combustion condition determining device for determining the conditions of combustion of the fuel in a zone of the flame extending along different strata thereof by collecting light in the flame at one point in the flame by moving such point. Signals outputted by the combustion condition determining device are utilized for monitoring or controlling the flame and controlling exhaust emission control devices for controlling exhaust emissions produced by the combustion of the fuel. Control of the conditions of combustion of the flame can be effected quickly with a high degree of precision by monitoring the flame.

Furnace system

Growing community of inventors

Ibaraki, Japan

Kiyoshi Narato