RU210008U1 - Flue gas recirculation device for power boilers - Google Patents

Abstract

The utility model relates to the field of energy, in particular to the recycling of combustion products during fuel combustion, and can be used in the reconstruction of power boilers in operation to reduce nitrogen oxides generated during fuel combustion. The device for flue gas recirculation of power boilers contains a furnace, convective surfaces, a gas extraction unit, a suction section of the recirculation line, a fan, a discharge section of the recirculation line, a recirculation gas redistribution unit, a tube for supplying combustion air, burners, a pipe for supplying gaseous fuel. EFFECT: reduction of thermal nitrogen oxides formed during fuel combustion.

Description

The utility model relates to the field of energy, in particular to the recycling of combustion products during fuel combustion, and can be used in the reconstruction of power boilers in operation to reduce nitrogen oxides generated during fuel combustion.

An invention is known to reduce the formation of nitrogen oxides, including a furnace, convective surfaces, a gas extraction unit, a suction section of a recirculation line, a fan, a discharge section of a recirculation line, a tubular heat exchanger, a tube for supplying combustion air, a burner, a pipe for supplying gaseous fuel. The reduction in the formation of nitrogen oxides in this invention is carried out by taking part of the gases after the convective surfaces of the boiler and bypassing them into the furnace, and in the process of bypassing the gases are cooled to a temperature below the dew point by contact with the heat exchange surfaces [1].

The reasons preventing the achievement of the technical result indicated below when using the known invention taken as a prototype include the fact that the known invention does not provide for the possibility of redistributing bypass gases (hereinafter referred to as recirculation gases) between the tiers of burners, as a result of which an effective reduction in emissions cannot be ensured thermal oxides of nitrogen in power boilers.

EFFECT: reduction of nitrogen oxides formed during fuel combustion.

The claimed technical result is achieved in that the device for flue gas recirculation of power boilers includes a furnace, convective heating surfaces, a gas extraction unit, a suction section of the recirculation line, a fan, a discharge section of the recirculation line, a tube for supplying combustion air, burners, a pipe to supply gaseous fuel.

The peculiarity lies in the fact that in the proposed utility model, in the discharge section of the recirculation line, a recirculation gas redistribution unit is built in to separate the recirculation gas flow into two separate gas flows so that most of the recirculation gases are supplied to the zone with maximum heat flows of the power boiler.

The utility model is illustrated by a drawing showing the scheme of its implementation.

The essence of the utility model lies in the use of a recirculation gas redistribution unit designed to separate the gases taken after the convective surfaces of the boiler, before passing them into the furnace, into two separate gas flows, most of which are supplied to the zone with maximum heat flows of the power boiler.

The device for flue gas recirculation of power boilers contains a furnace 1, convective surfaces 2, a gas extraction unit 3, a suction section 4 of the recirculation line, a fan 5, an injection section 6 of the recirculation line, a recirculation gas redistribution unit 7, a tube 8 for supplying combustion air, burner device 9, pipe 10 for supplying gaseous fuel.

The device for flue gas recirculation of power boilers is implemented as follows.

The resulting gas-air mixture burns in the furnace 1. The main part of the combustion products, having transferred heat to the convective surfaces 2, leaves the power boiler, and 5-25% of the combustion products through the gas extraction unit 3 is sent to the suction section 4 of the recirculation line and the fan 5 is fed into the discharge section 6 recirculation lines. In section 6, a recirculation gas redistribution unit 7 is placed, which separates the flow of combustion products into two separate gas flows supplied to the combustion air supply pipe 8. Block 7 redistribution of recirculation gases allows you to reduce the maximum temperature, which is the main indicator of the effectiveness of the formation of thermal oxides of nitrogen, in the zone with the maximum heat flow of the power boiler.

The combustion air flow through the tube 8 and the gas through the pipe 10 for supplying gaseous fuel enter the burner devices 9 for the formation of a gas-air mixture and subsequent combustion in the furnace 1.

Literature

1. USSR patent for invention No. 1509575, publ. 09/23/1989.

Claims (1)

A device for flue gas recirculation of power boilers, including a furnace, convective heating surfaces, a gas extraction unit, a suction section of the recirculation line, a fan, a discharge section of the recirculation line, a pipe for supplying combustion air, burners, a pipe for supplying gaseous fuel, different by the fact that in the injection section of the recirculation line, a recirculation gas redistribution unit is built in to separate the recirculation gas flow into two separate gas flows so that most of the recirculation gases are supplied to the zone with maximum heat flows of the power boiler.

Images