Circulating coal fluidized bed coal gas producer system

Abstract

The present invention relates to a circulating coal fluidized bed coal gas producer system, including a coal gas producer, a high temperature separator, a heat exchanger, a low temperature separator, and a waste heat boiler, which are connected successively, wherein the coal gas producer is provided with a first air inlet and at least one secondary air inlet for feeding high temperature gasification agent into the producer, and is provided with a circulating coal inlet for feeding circulating coal into the producer, the first air inlet and the secondary air inlet are connected to the heat exchanger, and the circulating coal inlet is connected to the high temperature separator, the low temperature separator and the heat exchanger respectively. In the present invention, with designs of entering air twice, feeding coal at two inlets, two separations and circulations of powder coal, the temperature of gasification agent when fed into the producer could reach 750° C.-850° C. Reaction heat consumption between the powder coal and the gasification agent is 20% lower than that of prior art. The combustible ingredient in coal gas is 20% higher than that of prior art. The coal consumption decreases to about 0.22 Kg/Nm 3 . The system has advantages of low coal consumption, high heat value, high productivity, and low cost.

1 . A coal gas producer system, comprising a coal gas producer, a high temperature separator, a heat exchanger, a low temperature separator, and a waste heat boiler, which are connected successively, wherein the coal gas producer is provided with a first air inlet and at least one secondary air inlet for feeding high temperature gasification agent into the producer, and is provided with a circulating coal inlet for feeding circulating coal into the producer, the first air inlet and the secondary air inlet are connected to the heat exchanger, and the circulating coal inlet is connected to the high temperature separator, the low temperature separator and the heat exchanger respectively. 
   
   
       2 . The system according to  claim 1 , wherein the coal gas producer is provided with a coal gas outlet, a lower raw coal inlet and at least one upper raw coal inlet, the lower raw coal inlet and the upper raw coal inlet are connected a coal supplier, and the coal gas outlet is connected to the high temperature separator. 
   
   
       3 . The system according to  claim 1 , wherein star shaped material feeders are respectively disposed between the high temperature separator and the circulating coal inlet, and between the low temperature separator and the circulating coal inlet. 
   
   
       4 . The system according to  claim 1 , wherein the heat exchanger is further connected to an air blower and the waste heat boiler respectively. 
   
   
       5 . The system according to  claim 1 , wherein the system further comprises a Venturi scrubber connected to the waste heat boiler and comprises a washing tower connected to the Venturi scrubber, a sedimentation tank is disposed at the bottom of the washing tower, a slag eliminator is disposed at the bottom of the sedimentation tank, and a cooling tower is disposed between a cooling water inlet and a cooling water outlet of the washing tower. 
   
   
       6 . The system according to  claim 1 , wherein temperature of the gasification agent when entering the producer via the first air inlet and the secondary air inlet is 750° C.-850° C. 
   
   
       7 . The system according to  claim 1 , wherein amount of first gasification agent entering the producer via the first air inlet is 50%-60% of total amount of gasification agent at the heat exchanger, amount of secondary gasification agent entering the producer via the secondary air inlet is 35%-45% of the total amount of the gasification agent at the heat exchanger. 
   
   
       8 . The system according to  claim 2 , wherein the coal gas producer comprises a producer body, bottom of the producer body is connected to a gas incoming chamber, air caps are disposed between the producer body and the gas incoming chamber, the first air inlet is disposed at the gas incoming chamber, and the lower raw coal inlet is disposed within a dense phase section of the producer body. 
   
   
       9 . The system according to  claim 8 , wherein there are 1-4 secondary air inlets, one of the secondary air inlets is located between the dense phase section and a dilute phase section of the producer body, and the other secondary air inlets are disposed within the dilute phase section of the producer body. 
   
   
       10 . The system according to  claim 8 , wherein the circulating coal inlet is disposed within the dense phase section of the producer body. 
   
   
       11 . The system according to  claim 8 , wherein the upper raw coal inlet is disposed within a dilute phase section of the producer body. 
   
   
       12 . The system according to  claim 8 , wherein an inclined tube is disposed at the circulating coal inlet, the inclined tube is connected to star shaped material feeders via pipelines, and an angle between the inclined tube and the axis of the producer body is 20°-30°. 
   
   
       13 . The system according to  claim 8 , wherein the producer body has an inner structure with a larger upper part and a smaller lower part, and a cross-section area of the upper part is 3-7 times of that of the lower part. 
   
   
       14 . The system according to  claim 8 , wherein an explosion-proof membrane orifice is disposed at upper part of the producer body, and a slag removal pipe is disposed at lower part of the producer body. 
   
   
       15 . The system according to  claim 8 , wherein there are 6-8 nozzles holes disposed on each of the air caps and a diameter of each of the nozzle holes is 4 mm-6 mm. 
   
   
       16 . The system according to  claim 8 , wherein a distance between the upper raw coal inlet and the lower raw coal inlet is 4000 mm-5000 mm. 
   
   
       17 . The system according to  claim 1 , wherein amount of gasification agent entering the producer via the circulating coal inlet is 5% of the total amount of the gasification agent at the heat exchanger.