A low-nitrogen combustion cooling-condensing integrated gas water heater

Abstract

A low-nitrogen combustion cooling and condensing integrated gas water heater, the gas water heater comprises a fan, a gas-air mixing chamber, a burner, a combustion chamber, a heat exchanger and a smoke exhaust guiding chamber from top to bottom. The heat exchanger contains multiple heat exchange tube rows and water distribution boxes; except that the water flow direction of the heat exchange tubes in the last heat exchange tube row is the same, the flow direction between adjacent heat exchange tube groups in the same heat exchange tube row is the same. The direction of the water flow is opposite, and the heat exchange tube groups are connected in sequence from the end to the end through the water distribution boxes on both sides. The invention not only effectively reduces NOx emissions from gas water heaters, but also integrates cooling and condensation to further reduce the exhaust gas temperature to below the flue gas dew point temperature. Compared with the prior art, it achieves low nitrogen oxide flue gas emissions and has better Anti-corrosion performance, compared with the existing condensing gas water heater, the material consumption is reduced by 24~44%, the smoke resistance is reduced by 67~96%, and the natural gas consumption is saved by about 24% compared with the traditional cooling gas water heater.

Description

technical field [0001] The invention relates to a gas water heater, in particular to a low-nitrogen combustion integrated cooling and condensation gas water heater, which belongs to the technical field of natural gas combustion and heating equipment. Background technique [0002] The flame temperature of natural gas combustion in gas water heaters is generally around 950°C, and a large amount of nitrogen oxides are generated during combustion. Water in the flue gas exists in the flue gas in gaseous form (water vapor). The latent heat of water vapor is about 11% of the low calorific value of natural gas. %. At present, the exhaust gas temperature of the mainstream cooling gas water heaters on the market is concentrated at 100°C-200°C. At this time, the water vapor in the flue gas tail gas has not yet condensed, so that the latent heat of water vapor and the sensible heat of exhaust gas at a higher temperature have not been obtained. Effective utilization, resulting in a larg...

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Problems solved by technology

Chinese patent documents CN20140224661.8 and CN201410431156.5 also disclose a condensing gas water heater respectively. The common feature of their water heaters is that they directly add heat exchange tubes and drainage systems on the basis of traditional cooling heat exchangers, thereby increasing the Heat exchange area, although this solution achieves low-temperature emission of flue gas, but at the same time there are problems such as increased raw material consumption, increased cost, and increased volume of heat exchangers

In addition, the common problem of all kinds of existing gas water heaters is that the heat exchange tubes are connected by elbows. Scale accumulation is easy to occur at the elbows, which increases the resistance of the pipelines and even causes pipe plugging. The problem that adjacent heat exchange tube rows cannot be arranged compactly due to radius restrictions

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