Provided is a combustion system using a catalyst having better denitration efficiency at low temperatures, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent.

This combustion system comprises: a combustion device that combusts fuel; an exhaust path through which flows exhaust gas generated from the combustion of fuel in the combustion device; a dust collection device that is arranged on the exhaust path and collects soot/dust in the exhaust gas; and a denitration device that is arranged on the exhaust path and removes nitrogen oxides from the exhaust gas by means of a denitration catalyst, wherein the denitration device is arranged downstream of the dust collection device on the exhaust path, and the denitration catalyst contains vanadium oxide, has a carbon content of 0.05 wt % or more, and has a defect site in which oxygen deficiency occurs in a crystal structure.

In a high-efficient clean, high-variable load rate coal-fired power generation system, through the internal thermal source SCR denitration catalytic module coupled with high temperature and low temperature storage tanks, the operating temperature of the internal thermal source SCR denitration catalytic module is controlled in a range of 300° C. to 400° C., ensuring that the SCR catalyst has high activity in full-working conditions. Moreover, the high temperature and low temperature storage tanks are coupled with the high-pressure heater group for steam turbine regenerative system, so that when the coal-fired unit needs to increase load rate, the thermal storage energy is quickly converted into output power. In addition, energy stored in the high temperature and low temperature storage tanks come from both the internal thermal source SCR denitration catalytic module and the thermal storage medium heater within the boiler, the operational flexibility and the boiler efficiency are improved.

An integrated comprehensive adjustment method for a pulverized coal boiler based on high-temperature corrosion prevention and control of water wall is provided. The method includes: during shutdown period of the boiler, mounting reducing atmosphere sampling pipe on a water-cooled wall region; carrying out a diagnostic test on the boiler; carrying out an optimization and adjustment test of a boiler pulverizing system; carrying out a single-factor adjustment test of boiler-related parameters; determining degrees of influence of different parameters on water wall reducing atmosphere, thermal efficiency of the boiler and NO.sub.x concentration at a denitration inlet; carrying out an optimization test of ammonia spraying of a denitration system; carrying out a maximum safe denitration efficiency test; and finding a balance point among the water wall reducing atmosphere, the thermal efficiency of the boiler and the NO.sub.x concentration at the denitration inlet.

Provided is a combustion system using a catalyst having better denitration efficiency at low temperatures, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent.

This combustion system comprises: a combustion device that combusts fuel; an exhaust path through which flows exhaust gas generated from the combustion of fuel in the combustion device; a dust collection device that is arranged on the exhaust path and collects ash dust/dust in the exhaust gas; and a denitration device that is arranged on the exhaust path and removes nitrogen oxides from the exhaust gas by means of a denitration catalyst, wherein the denitration device is arranged downstream of the dust collection device on the exhaust path, and the denitration catalyst contains vanadium oxide including vanadium pentoxide and has a defect site in which an oxygen atom is deficient in a crystal structure of the vanadium pentoxide.

An exhaust gas treatment device includes an exhaust gas line through which a combustion exhaust gas discharged from a power generation facility flows, a waste heat recovery boiler recovering waste heat of the combustion exhaust gas, a branch exhaust gas line provided to be connected between a front stage and a downstream stage of the waste heat recovery boiler on a main exhaust gas line, a nitrogen oxide removal unit removing nitrogen oxide in an integrated combustion exhaust gas into which a combustion exhaust gas flowing through the main exhaust gas line and a combustion exhaust gas flowing through the branch exhaust gas line are integrated, an integrated waste heat recovery boiler recovering waste heat of the integrated combustion exhaust gas from which nitrogen oxide has been removed, and a CO.sub.2 recovery unit recovering CO.sub.2 in the integrated combustion exhaust gas.

The present disclosure provides a cerium-zirconium-based composite oxide with a core-shell structure and a preparation method thereof, a catalyst system using the cerium-zirconium-based composite oxide, a catalytic converter for purifying tail gas by using the catalyst system, and application of the catalyst system or the catalytic converter in motor vehicle exhaust purification, industrial waste gas treatment or catalytic combustion. In the present invention, the cerium-zirconium-based composite oxide with a core-shell structure oxygen storage material is prepared by a step-by-step precipitation method. On the one hand, yttrium and a part of zirconium and cerium are precipitated on a cerium-zirconium surface, where the post-precipitation of yttrium is to segregate yttrium ions (Y.sup.3+) on a grain boundary surface, thus reducing lattice surface energy, pinning the grain boundary surface, making the migration of the grain boundary surface difficult, controlling the growth of grains.

The present disclosure relates to a cerium-zirconium-based composite oxide having gradient element distribution and a preparation method therefor. According to the present disclosure, the cerium-zirconium-based composite oxide having gradient element distribution is prepared by a step-by-step precipitation method. First, a zirconium-rich component is precipitated to form a crystal structure and a crystal grain stack structure which have high thermal stability, slow down the segregation of zirconium on a surface after high-temperature treatment, and reduce element migration among crystal grains; second, a cerium-rich component is precipitated to improve the cerium content of the surface layers of the crystal grains, improve the utilization rate of the cerium element, and improve the oxygen storage amount and the oxygen storage rate.

Some non-limiting embodiments of the present disclosure relate to a method of regenerating at least one filter medium, the method comprising flowing a flue gas stream through or by the at least one filter medium at a first temperature and increasing the temperature of the flue gas stream from the first temperature to a second temperature that exceeds the first temperature. Some non-limiting embodiments of the present disclosure relate to a method of cleaning a flue gas stream, the method comprising maintaining the NO.sub.x removal efficiency by increasing the temperature of the flue gas stream from the first temperature to a second temperature that exceeds the first temperature.

A vehicle heater includes a burner assembly unit (12) with a combustion chamber (18) to be fed with combustion air (V) and fuel (B) and a flame tube (24). A heat exchanger assembly unit (14) includes an inner heat exchanger housing (28) with an inner circumferential wall (30) and an outer heat exchanger housing (34) with an outer circumferential wall (36). A heat transfer medium flow space (40) is between the inner and outer heat exchanger housings, which are elongated in a longitudinal axis (L) direction. A waste gas backflow space (44), between the inner circumferential wall (30) and the flame tube, opens towards an exhaust gas outlet. A catalytic converter device (52) is provided in the waste gas backflow space associated with an energizable heating unit (58), or/and insulation material (64) is provided on an outer side (62) facing away from the heat transfer medium flow space.

Provided is a combustion system using a catalyst having better denitration efficiency at low temperatures, during a selective catalytic reduction reaction in which ammonia is used as a reducing agent. This combustion system comprises: a combustion device that combusts fuel; an exhaust path through which flows exhaust gas generated from the combustion of fuel in the combustion device; a dust collection device that is arranged on the exhaust path and collects ash dust/dust in the exhaust gas; and a denitration device that is arranged on the exhaust path and removes nitrogen oxides from the exhaust gas by means of a denitration catalyst, wherein the denitration device is arranged downstream of the dust collection device on the exhaust path, and the denitration catalyst contains vanadium oxide including vanadium pentoxide and has a defect site in which an oxygen atom is deficient in a crystal structure of the vanadium pentoxide.