Gas-fired steam-injection boiler for oil field

Abstract

A gas-fired steam-injection boiler has a flue and a water supply pipeline. The flue is provided with a radiation section and a convection section. The water supply pipeline has, in the flue gas flow direction, a first pipe section located at an upstream portion of the convection section, a second pipe section is located at a downstream portion of the convection section, and a third pipe section arranged between the first pipe section and the second pipe section. In a water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section are arranged in sequence. By using a flue gas condenser, the temperature of flue gas can be further reduced, and the latent heat of vaporization of steam in the flue gas is absorbed to form condensate water.

1 . A gas-fired steam-injection boiler for oil field, comprising a flue having a radiation section ( 1 ) and a convection section ( 2 ) that are arranged in a flue gas flow direction, and a water supply pipeline comprising a first pipe section, a second pipe section, and a third pipe section,
 wherein in the flue gas flow direction, the first pipe section is located upstream the convection section ( 2 ), the second pipe section is located downstream the convection section ( 2 ), and the third pipe section is arranged between the first pipe section and the second pipe section; and   wherein in a water flow direction of the water supply pipeline, the second pipe section, the first pipe section and the third pipe section ( 3 ) are arranged sequentially.   
     
     
         2 . The gas-fired steam-injection boiler for oil field of  claim 1 , wherein the first pipe section is a plain pipe ( 21 ) of the convection section, and the second pipe section is a finned pipe ( 22 ) of the convection section. 
     
     
         3 . The gas-fired steam-injection boiler for oil field of  claim 1 , wherein the third pipe section ( 3 ) comprises a plain pipe for evaporation ( 31 ) and a finned pipe for evaporation ( 32 ) that are arranged in the water flow direction of the water supply pipeline, and the plain pipe for evaporation ( 31 ) and the finned pipe for evaporation ( 32 ) are arranged sequentially in the flue gas flow direction of the convection section ( 2 ). 
     
     
         4 . The gas-fired steam-injection boiler for oil field of  claim 1 , wherein the third pipe section ( 3 ) is arranged in a region at 800-900° C. in the convection section ( 2 ). 
     
     
         5 . The gas-fired steam-injection boiler for oil field of  claim 1 , wherein the radiation section ( 1 ) extends horizontally, an opening is provided in an upper part of a downstream end of the radiation section ( 1 ), and the convection section ( 2 ) is in communication with the upper part of the downstream end of the radiation section ( 1 ) and extends upward vertically. 
     
     
         6 . The gas-fired steam-injection boiler for oil field of  claim 5 , wherein the flue comprises a condensation section ( 4 ) extending upward vertically from an upper end of the convection section ( 2 ). 
     
     
         7 . The gas-fired steam-injection boiler for oil field of  claim 6 , wherein the water supply pipeline comprises a heat exchange plain pipe ( 41 ) of the condensation section arranged in the condensation section ( 4 ), which is located upstream the second pipe section in the water flow direction of the water supply pipeline. 
     
     
         8 . The gas-fired steam-injection boiler for oil field of  claim 7 , wherein the water supply pipeline is provided with a deaerator ( 10 ) and a pressure pump ( 11 ) between the heat exchange plain pipe ( 41 ) of the condensation section and the second pipe section, and is provided with a water tank  8  and a softener  9  upstream the heat exchange plain pipe ( 41 ) of the condensation section. 
     
     
         9 . The gas-fired steam-injection boiler for oil field of  claim 6 , further comprises a condensation baffle ( 5 ) at a lower part of the condensation section ( 4 ), and a water collection tank located below the condensation baffle ( 5 ) and connected to a recovery tank ( 6 ) through a pipeline. 
     
     
         10 . The gas-fired steam-injection boiler for oil field of  claim 5 , wherein the cross-sectional area of flow at a joint between a lower port of the condensation section ( 4 ) and an upper port of the convection section ( 2 ) is greater than that of the upper port of the condensation section ( 4 ), and a flue gas stack is provided at the upper port of the condensation section ( 4 ). 
     
     
         11 . The gas-fired steam-injection boiler for oil field of  claim 1 , wherein the water supply pipeline comprises a radiation pipe section in the radiation section ( 1 ), and the second pipe section, the first pipe section, the radiation pipe section and the third pipe section ( 3 ) are arranged sequentially in the water flow direction of the water supply pipeline. 
     
     
         12 . The gas-fired steam-injection boiler for oil field of  claim 11 , wherein the radiation section ( 1 ) comprises a high-temperature radiation section ( 16 ) and a low-temperature radiation section ( 17 ) that are arranged in the flue gas flow direction, and the radiation sections include a plain pipe ( 18 ) of the high-temperature radiation section in the high-temperature radiation section ( 16 ) and a plain pipe ( 19 ) of the low-temperature radiation section in the low-temperature radiation section ( 17 ), and the plain pipe ( 18 ) of the high-temperature radiation section and the plain pipe ( 19 ) of the low-temperature radiation section are arranged sequentially in the water flow direction of the water supply pipeline.