Control method of household gas water heater using hydrogen as fuel

Abstract

The invention discloses a control method of a household gas water heater using hydrogen as fuel, the method combines a staged combustion technology and a fully premixed combustion technology, a controller judges a combustion mode according to water inlet flow and a set hot water input temperature, and two electromagnetic valves and a staged combustor are arranged to control the combustion mode of the household gas water heater. Meanwhile, the stable combustion of the hydrogen is realized by matching with the rotation speed adjustment of the fan and the current of the gas proportional valve; an oxygen sensor is arranged on the smoke exhaust pipe, and the controller judges whether actual hydrogen combustion reaches the optimal state or not by monitoring the outlet water temperature and the oxygen concentration in smoke and conducts adjustment. By means of the device, the household gas water heater can have the large thermal load adjusting range and the constant-temperature hot water output function when hydrogen serves as fuel, safe and stable combustion of hydrogen on the gas water heater is achieved, and hydrogen combustion tempering and corrosion of condensate water to the water heater are avoided.

Description

Technical field [0001] The present invention belongs to the field of urban gas combustion and applications, in particular to a hydrogen-fueled household gas water heater control method. Background [0002] At present, the gas source of household gas water heaters is mainly natural gas and liquefied petroleum gas, with the national "carbon peak, carbon neutrality" goal proposed, hydrogen energy as a clean and low-carbon green energy, is expected to be popularized in the field of household gas water heaters. However, the physicochemical properties of hydrogen are quite different from those of natural gas and liquefied petroleum gas, resulting in the inability to burn stably on existing gas water heaters. The existing gas water heater flameout protection device mostly uses flame induction needles to monitor the flame combustion state, the principle is that the ions generated by the combustion of natural gas or liquefied petroleum gas form an ionization current on the induction need...

AI Technical Summary

Problems solved by technology

Patent Publication No. CN110207386A is an invention patent "a staged combustion gas water heater and its control method". The switch of the firepower gear is realized by controlling the switch of the section valve through the controller, and the current linkage control method is used to control the different firepower stages. The position is limited in the current range of different gas proportional valves; the invention patent of patent publication number CN111520713A "A Closed Full Premixed Combustion System and Water Heater" uses a full premixed method of injecting air with gas, and the injection tube The amount of air injection is controlled by the gas pressure and the fan speed, and the combustion segment control is realized on the basis of full premixed combustion; but the above patents only realize two-stage combustion, which cannot meet the requirements when hydrogen is used as fuel. The reduction of the adjustment range caused by the substantial reduction of the heat load; at the same time, the above patents all use an upward-drawing fan, which is installed at the top, and the amount of air entering the burner cannot be precisely controlled, which may easily lead to unstable combustion, and condensation generated by hydrogen combustion Water will affect the life of the fan

[0004] Patent Publication No. CN112146286A "A Gas Water Heater Air Volume Matching Control Method and Control System", according to the fire section and the program segmented air volume adjustment relationship matching the heat load of this fire section, determine the theoretical fan air volume to adjust ; But this patent is only adjusted through the theoretical air volume of the fan, and cannot judge the actual air volume required for combustion, and cannot guarantee the best combustion effect

Patent Publication No. CN112113349A's invention patent "A Water Heater Control Method and Water Heater", judges whether the water heater is burning stably by detecting the noise value of the current segmented water heater and the wind pressure value of the air duct; but this invention cannot accurately sense the fluctuation of the combustion state , susceptible to interference from environmental noise; at the same time, when the maximum heat load is reached, the invention maintains the balance between air volume and gas volume by reducing the gas proportional valve, which will lead to a drop in the temperature of the hot water outlet, which cannot meet the requirements of constant temperature hot water

The invention patent of patent publication number CN110274395A "A Control Method for Self-adaptive Fully Premixed Gas Water Heater and Gas Water Heater" monitors the combustion of the water heater by collecting gas flow, fan flow and excess oxygen content after combustion; but the The invention does not adopt staged combustion technology, which cannot achieve large heat load adjustment and cannot meet the constant temperature hot water output; and when hydrogen fuel is used, when the heat load of the water heater changes, the flow rate of hydrogen in the burner cannot be kept within the tempering limit inside, thus prone to tempering phenomenon

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