System for supplying heat by means of stratum coal in-place slurrying and method for supplying power generation heat by means of stratum coal in-place slurrying

A method for supplying power generation heat by means of stratum coal in-place slurrying by using a system for supplying heat by means of stratum coal in-place slurrying,

• the system comprising a stratum coal slurrying device, a well casing device and a heat exchange device;
• the stratum coal slurrying device comprises a water inlet pump and a coal slurry pump, which are connected to a directional slurry preparing drill through pipelines, respectively;
• the well casing device comprises a vertically buried pipe and a heat-insulating inner pipe that is coaxial with the vertically buried pipe and inserted into the vertically buried pipe, with a microporous pipe assembly being arranged on a bottom of the heat-insulating inner pipe, electric heaters being arranged in the microporous pipe assembly, an annular cavity being formed between the vertically buried pipe and the heat-insulating inner pipe, a power wire-connected to the electric heaters being arranged in the annular cavity, and the coal slurry pump being connected to the annular cavity;
• and the heat exchange device comprises a water outlet pipe that is inserted into the heat-insulating inner pipe and connected to the microporous pipe assembly, and the water outlet pipe is connected to a heat exchanger,
• the method comprising:
• a step of in-place preparing slurry by the stratum coal slurrying device, a step of combusting coal slurry by the well casing device, and a step of exchanging heat and generating power by the heat exchange device, wherein:
• in the step of in-place preparing slurry by the stratum coal slurrying device, water is conveyed to the directional slurry preparing drill by the water inlet pump, a coal bed in an underground coal storage area is cut and grinded into coal slurry having a particle size of 100 to 200 μm by the directional slurry preparing drill, and the coal slurry is conveyed to the ground surface by the coal slurry pump;
• in the step of combusting coal slurry by the well casing device, the coal slurry having particle size of 100 to 200 μm is injected into the annular cavity between the vertically buried pipe and the heat-insulating inner pipe, electric heaters heat the microporous pipe assembly to raise the temperature of water near the microporous pipe assembly to above 400° C. so that the coal slurry undergoes thermal oxidation reaction, the coal slurry pump is continuously fed, and reacted hot water is conveyed to the heat exchanger through the water outlet pipe;
• and
• in the step of exchanging heat and generating power by the heat exchange device, heat is exchanged with working medium water by the heat exchanger to generate power.