Boiler
This boiler has a flue in which a reducing agent supplying device and a selective reduction catalyst are provided, a bypass flow path bypassing economizers is provided, and a first closing device partially closing the bypass flow path and a second closing device partially closing the flue are also provided. A plurality of first closing members, serving as the first closing device, are provided along the direction in which exhaust gas flows through the flue at a predetermined spacing in the width direction of the flue. A plurality of second closing members, serving as the second closing device are provided along the vertical direction at a predetermined spacing in the width direction of the flue. The first closing members and the second closing members are arranged so as to be displaced from each other in the width direction of the flue.
1. A boiler comprising:
a furnace having a hollow shape and installed along a vertical direction;
a combustion device disposed in the furnace;
a flue connected to an upper portion of the furnace in the vertical direction to cause flue gas to flow therethrough;
a heat exchanger disposed in the flue;
a reducing agent supplying device disposed on the further downstream side in a flow direction of the flue gas with respect to the heat exchanger in the flue;
a denitration catalyst disposed on the further downstream side in the flow direction of the flue gas with respect to the reducing agent supplying device in the flue;
a bypass flow path having one end portion connected to the further upstream side in the flow direction of the flue gas with respect to the heat exchanger in the flue, and the other end portion connected between the heat exchanger and the reducing agent supplying device in the flue;
a first closing device which is provided on the further upstream side in the flow direction of the flue gas with respect to a downstream side connection portion with the flue, to which the other end portion of the bypass flow path is connected, and partially closes the bypass flow path; and
a second closing device which is provided on the further upstream side with respect to the downstream side connection portion in the flue and partially closes the flue,
wherein the first closing device has a plurality of first closing members extending along the flow direction of the flue gas in the flue and provided at predetermined intervals in a width direction of the flue,
the second closing device has a plurality of second closing members extending along a vertical direction and provided at predetermined intervals in the width direction of the flue,
a mixing space section is provided adjacent to the plurality of first closing members and the plurality of second closing members and at a position facing the downstream side connection portion on the further downstream side with respect to the first closing device in the flue,
the plurality of first closing members and the plurality of second closing members are disposed to be shifted with respect to each other in the width direction of the flue, and the flue gas flowing from the bypass flow path to the mixing space section through gaps between the respective first closing members and the flue gas flowing from the flue to the mixing space section through gaps between the respective second closing members do not directly collide with each other.
2. The boiler according to claim 1 , wherein the flue is provided with a straight flue section, and the second closing device and the reducing agent supplying device are disposed in the straight flue section.
3. The boiler according to claim 2 , wherein a flow rate adjustment damper is disposed on the further upstream side with respect to the second closing device in the straight flue section.
4. The boiler according to claim 1 , wherein a mixing space section is provided at a position facing the downstream side connection portion on the further downstream side with respect to the first closing device in the flue.
5. The boiler according to claim 4 , wherein the first closing device and the second closing device are disposed to face the mixing space section.
6. The boiler according to claim 1 , wherein the second closing member is a closing plate extending along a direction orthogonal to the flow direction of the flue gas in the flue and is set to have the same width along the vertical direction.
7. The boiler according to claim 6 , wherein a reinforcing plate extending to the downstream side in the flow direction of the flue gas is fixed to the closing plate.