Waste heat recovery product well system for ISC and operation method thereof

Abstract

The invention provides a waste heat recovery product well system for ISC and an operation method of the waste heat recovery product well system for the ISC. The waste heat recovery product well system for the ISC comprises a product pipe, a jacketed pipe, a water cooling pipe, a monitoring instrument system, a product well bushing, a high-temperature high-pressure wellhead device, a ground waste heat recovery device and the like. Each component in the product well system is easy to recycle and reutilize. Heat carried out by high-temperature high-pressure downhole steam can be used for the ground production technology, turbine power generation, boiler power generation, other ground public facilities or plant life purposes and the like. By the adoption of the waste heat recovery product well system for the ISC and the operation method of the waste heat recovery product well system for the ISC, effective monitoring, control and protection of a product well can be achieved, waste heat of high-temperature crude synthesis gas is reliably and effectively recycled and comprehensively utilized, the consumption of cooling water is significantly reduced, and the requirement for downstream waste water treatment is lowered, comprehensive and efficient utilization of coal is achieved, the energy consumption of the whole ISC is lowered, and the technical problems faced by the existing ISC are finally solved.

Description

technical field [0001] The invention relates to a waste heat recovery system and an operation method, in particular to a waste heat recovery product well system and an operation method for an underground coal gasification process. Background technique [0002] Underground coal gasification (ISC) is a process that converts coal directly into gas products through controlled combustion (incomplete combustion) and gasification reactions of underground coal seams. The product gas, often called syngas, can be used as a feedstock for downstream processes such as fuel production, chemical production, power generation, and more. This process integrates well construction and completion, underground coal mining and coal gasification technology, and has the advantages of good safety, small investment, high benefit and less pollution. [0003] Drilling directly through the coal seam provides an effective channel for oxidant injection and product gas output. One well drilled for oxidant...

AI Technical Summary

Problems solved by technology

When the temperature exceeds the yield stress failure temperature of the casing material of the production well, it will eventually cause damage to the production well

[0007] (2) Damage to casing and / or cement bonded locations due to restricted thermal expansion (thermal elongation) of cemented casing

[0008] (3) Bending deformation of the product pipe due to thermal elongation of the free suspension (self-weight) product pipe in the vertical or directional product well without consideration

[0009] (4) Deterioration and damage of product well integrity due to wet corrosive syngas

[0010] (5) During the ignition process, due to the low temperature of the product well, the volatile matter of coal and the heavy components of pyrolysis products (tar, asphalt, etc.) are easy to condense in the product well and mix with solid particles and coal ash, eventually resulting in some or completely blocked

Similarly, when the load of underground gasification is reduced, the product well is blocked due to the temperature drop of the product well and the incomplete entrainment of solid and liquid impurities in the gas flow.

[0011] (6) Insufficient underground monitoring and instrumentation system for product wells, which makes it impossible to detect and deal with blockage and / or damage of product wells in advance

[0012] (7) Product wells do not have sufficient safety system equipment and treatment methods to deal with high-temperature product well damage, leakage of gas pollutants, and excessive formation pressure caused by insufficient design and configuration of abnormal system operation

[0013] (8) There is no product well equipment that is easily recycled and reusable

[0014] (9) There is no suitable process to recover the waste heat in the underground crude syngas to reduce the energy consumption of the entire underground coal gasification (ISC) process

Images