CN107120837A - A kind of high effective flue gas circulatory system and its gas heater - Google Patents

Abstract

The invention discloses a high-efficiency flue gas circulation system, which includes a main controller and a circulation intake pipeline connected between the flue gas of the heat exchanger and the combustion chamber, and is characterized in that the circulation intake pipeline is connected to a gas water heater In the secondary heat exchanger, an electric control valve is arranged on the circulation air intake pipeline, and the main controller is electronically connected with the electric control valve. The invention also discloses a gas water heater with a high-efficiency flue gas circulation system. The invention can reduce the temperature of the combustion chamber, prevent gas deflagration, is safe and reliable, can efficiently suppress the formation of nitrogen oxides, not only improves the efficiency of hot water, but also reduces the discharge of nitrogen oxides.

Description

A high-efficiency flue gas circulation system and its gas water heater

technical field

The invention relates to the technical field of heating devices, in particular to the technical field of flue gas circulation systems such as gas water heaters.

Background technique

Existing condensing gas water heaters use high-temperature flue gas to perform secondary heat exchange on cold water. pollute.

There are also those that adopt tail gas recycling, such as the invention whose patent name is gas water heater tail gas recycling device (CN201020134062.9), publication (announcement) number is CN201662234U, application date is: 2010.03.15, and publication (announcement) date is 2010.12.01 The patent relates to a gas water heater tail gas recycling device, which belongs to the technical field of gas water heaters. Combustion, the combustion chamber is also provided with a secondary tail gas outlet. The invention connects the tail gas to the combustion chamber for secondary combustion, effectively reducing the content of carbon monoxide, nitrogen monoxide and unburned combustible gases in the tail gas, and preventing poisoning events. However, due to the fact that the flue gas temperature is too low on the one hand and the addition amount is uncontrollable on the other hand, it will affect the combustion performance and cannot achieve the best effect.

Contents of the invention

The object of the present invention is to provide a high-efficiency flue gas circulation system capable of secondary utilization of high-temperature flue gas in view of the deficiencies of the prior art.

Another object of the present invention is to provide a gas-fired water heater using the above-mentioned high-efficiency flue gas circulation system, making it a real energy-saving and emission-reducing product.

In order to achieve the above purpose, the patent of the present invention adopts the following technical solutions:

A high-efficiency flue gas circulation system, including a main controller, and a circulation intake pipeline connected between the flue gas of the heat exchanger and the combustion chamber. An electric control valve is arranged on the circulating air intake pipeline, and the main controller is electrically connected with the electric control valve.

As a further description of the above solution, the main controller controls the opening and closing of the electric control valve according to the combustion load status of the gas water heater, the fan speed and the oxygen concentration of the combustion chamber;

A gas water heater with a high-efficiency flue gas circulation system of the present invention includes a primary heat exchanger, a secondary heat exchanger, a strong blower DC fan, a combustion chamber, and a main controller. On the intake pipeline, it is characterized in that there is a circulation intake pipeline between the flue gas of the secondary heat exchanger and the combustion chamber, and an electric control valve is arranged on the circulation intake pipeline, and the main controller is electrically connected with the electric control valve .

Further, the circulation air intake line is in communication with the air intake line.

A high-efficiency flue gas circulation system provided by the patent of the present invention has the following beneficial effects:

1. In the prior art, the high-temperature and high-pressure flue gas directly enters the combustion chamber, which may easily lead to deflagration, and after the flue gas is heat-exchanged and cooled, part of the flue gas is guided into the combustion chamber by the electric control valve, which reduces the temperature of the combustion chamber and prevents gas deflagration, which is safe and reliable .

2. The opening and closing of the electronically controlled air valve is determined according to the heat load of the whole machine, and the speed of the fan is detected. Controlling the amount of flue gas entering the combustion chamber can effectively suppress the formation of nitrogen oxides.

3. The flue gas circulation system makes secondary use of high-temperature flue gas, which not only improves the efficiency of hot water, but also reduces the emission of nitrogen oxides.

Description of drawings

Fig. 1 is a structural schematic diagram of the working principle of the present invention.

Explanation of reference signs: 1. Secondary heat exchanger 2. Primary heat exchanger 3. Combustion chamber 4. Main controller 5. Strong blower direct current blower 6. Electric control air valve 7. Circulating air intake pipeline.

detailed description

Below in conjunction with accompanying drawing and embodiment the patent of the present invention will be further described.

As shown in Figure 1, the water heater of the present invention is mainly composed of a primary heat exchanger 2, a secondary heat exchanger 1, an electric control valve 6, a strong blower DC blower 5, a combustion chamber 3, and a main controller 4. , the strong blower DC blower 5 is set on the air intake pipeline of the combustion chamber 3, and the circulation intake pipeline 7 is provided between the flue gas of the secondary heat exchanger 1 and the combustion chamber 3, and the circulation intake pipeline 7 is provided with an electrical The control valve 6, the flue gas guide port of the circulation intake pipeline 7 is set on the right side of the secondary heat exchanger 1, the circulation intake pipeline 7 communicates with the air intake pipeline, and the opening and closing of this passage is controlled by the electronically controlled air valve 6 , the main controller 4 controls the opening and closing of the electric control valve 6 according to the combustion load status of the gas water heater, the fan speed and the oxygen concentration of the combustion chamber 3 .

working principle:

The water heater works and burns. When the high-temperature flue gas reaches the secondary heat exchanger 1, it first exchanges heat with the cold water in the water pipe, and then the hot water enters the primary heat exchanger 2 to be heated and then flows out. When the fan is running at high speed, the water heater is burning under high load, the blast is enhanced, and the oxygen concentration is high. In the case of rich oxygen, nitrogen oxides are easy to be generated when burning. At this time, the main controller 4 controls the electronically controlled air valve 6 to open. Guide part of the flue gas into the mixed gas channel, and the flue gas dilutes the mixed gas to reduce the oxygen concentration and suppress the formation of nitrogen oxides NOx. When the water heater is burning under low load, the speed of the fan is reduced. At this time, the oxygen and gas in the air are fully combusted, and the formation of nitrogen oxides and NOx is low. Device 4 is electrically connected with the blower fan.

The invention point of the present invention is to provide a heat exchanger with a new structure, and to bring a part of the flue gas that has been heat-exchanged and cooled into the combustion chamber through an electric control valve, so as to reduce the temperature of the combustion chamber and the oxygen concentration in the diluted mixed gas .

What has been described above is only a preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, some modifications and improvements can be made without departing from the inventive concept of the present invention, and these all belong to the present invention. protection scope of the invention.

Claims (5)

1. A high-efficiency flue gas circulation system, comprising a main controller, a circulation intake pipeline connecting the flue gas of the heat exchanger and the combustion chamber, characterized in that, the circulation intake pipeline is connected to the secondary gas water heater The heat exchanger is provided with an electric control valve on the circulation air intake pipeline, and the main controller is electronically connected with the electric control valve. 2. The high-efficiency flue gas circulation system according to claim 1, wherein the main controller controls the opening and closing of the electric control valve according to the combustion load status of the gas water heater, the fan speed and the oxygen concentration of the combustion chamber; When running at high speed, the water heater burns under high load, the blast is enhanced, and the oxygen concentration is high. At this time, the main controller controls the electronically controlled air valve to open to guide part of the flue gas into the mixed gas channel, and the flue gas is diluted in the mixed gas. Reduce the oxygen concentration and suppress the formation of nitrogen oxides NOx. When the water heater is burning under low load, the speed of the fan is reduced. At this time, the oxygen and gas in the air are fully combusted, and the formation of nitrogen oxides NOx is low. The electronically controlled air valve is closed and no longer guides the flue gas into the combustion chamber. 3. A gas water heater with a high-efficiency flue gas circulation system, including a primary heat exchanger, a secondary heat exchanger, a strong blower DC fan, a combustion chamber, and a main controller. The strong blower DC fan is installed in the air inlet of the combustion chamber On the gas pipeline, it is characterized in that there is a circulation intake pipeline between the flue gas of the secondary heat exchanger and the combustion chamber, an electric control valve is arranged on the circulation intake pipeline, and the main controller is electrically connected with the electric control valve. 4. The gas water heater of the high-efficiency flue gas circulation system according to claim 3, characterized in that, the circulation air intake pipeline is connected with the air intake pipeline. 5. The gas water heater of the high-efficiency flue gas circulation system according to claim 3 or 4, wherein the main controller controls the opening and closing of the electric control valve according to the combustion load status of the gas water heater, the speed of the fan and the oxygen concentration of the combustion chamber. Closed; when the fan is running at high speed, the water heater is burning under high load, the blast is enhanced, and the oxygen concentration is high. In the mixed gas, the oxygen concentration is reduced to suppress the generation of nitrogen oxides NOx. When the water heater is burning under low load, the speed of the fan is reduced. At this time, the oxygen and gas in the air are fully combusted, and the formation of nitrogen oxides NOx is low. The electronically controlled air valve is closed and no longer guides the flue gas into the combustion chamber.