Development of high temperature air combustion technology in pulverized fossil fuel fired boilers
Development of high temperature air combustion technology in pulverized fossil fuel fired boilers
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DOI：
10.1016/j.proci.2006.07.135
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Hai Zhang;G. Yue;Junfu Lu;Zhen Jia;Jiangxiong Mao;T. Fujimori;T. Suko;T. Kiga
中科院分区：
文献类型：
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作者：
Hai Zhang;G. Yue;Junfu Lu;Zhen Jia;Jiangxiong Mao;T. Fujimori;T. Suko;T. Kiga
高温空气燃烧技术是一项具有广阔应用前景的节能、稳燃和减排技术。在传统的HTAC系统中，燃烧空气通过使用回热式或再生式热交换器被高度预热。然而，这种预热过程对于燃烧粉状化石燃料的锅炉来说难以实施。在本文中，提出了一种替代方法。在建议的HTAC系统中，一个特殊的燃烧器，名为PRP燃烧器被引入来完成预热过程。PRP燃烧器有一个预热室，一端与一次风连接，另一端向炉膛开放。在燃烧室内，有效地建立了气体再循环，从而可以引入炉内的热烟气。PRP燃烧器高度预热可燃混合物而不是燃烧空气。在工业试验装置上进行了一系列燃烧低挥发分石油焦和无烟煤的试验。分别建立了纯石油焦和无烟煤的稳定燃烧实验。在预热室内，可燃混合物被快速加热到接近传统HTAC系统中使用的热二次空气的高温水平。燃烧室中可燃混合物的快速加热有利于燃料颗粒的热解、挥发物释放过程，抑制着火延迟并提高燃烧稳定性。此外，与在相同的设施，但与传统的低NOx燃烧器的测量结果相比，在炉膛出口处的NOx浓度是在相同的水平时，石油焦燃烧和无烟煤燃烧时减少50%。实践证明，采用该方法的高温空气燃烧技术是可行的，可有效清洁地燃烧化石燃料。
High temperature air combustion (HTAC) is a promising technology for energy saving, flame stability enhancement and NOxemission reduction. In a conventional HTAC system, the combustion air is highly preheated by using the recuperative or regenerative heat exchangers. However, such a preheating process is difficult to implement for pulverized fossil fuel fired boilers. In this paper, an alternative approach is proposed. In the proposed HTAC system, a special burner, named PRP burner is introduced to fulfill the preheating process. The PRP burner has a preheating chamber with one end connected with the primary air and the other end opened to the furnace. Inside the chamber, gas recirculation is effectively established such that hot flue gases in the furnace can be introduced. Combustible mixture instead of combustion air is highly preheated by the PRP burner. A series of experiments have been conducted in an industrial scale test facility, burning low volatile petroleum coke and an anthracite coal. Stable combustion was established for burning pure petroleum coke and anthracite coal, respectively. Inside the preheating chamber, the combustible mixture was rapidly heated up to a high temperature level close to that of the hot secondary air used in the conventional HTAC system. The rapid heating of the combustible mixture in the chamber facilitates pyrolysis, volatile matter release processes for the fuel particles, suppressing ignition delay and enhancing combustion stability. Moreover, compared with the results measured in the same facility but with a conventional low NOxburner, NOxconcentration at the furnace exit was at the same level when petroleum coke was burnt and 50% less when anthracite was burnt. Practicability of the HTAC technology using the proposed approach was confirmed for efficiently and cleanly burning fossil fuels.