CN206637834U - A kind of gas heater with smoke circulating system - Google Patents

Abstract

The utility model discloses a gas water heater with a flue gas circulation system, which comprises: a combustion chamber, a strong blower DC fan connected with the combustion chamber, a primary heat exchanger, a secondary heat exchanger, and a strong blower DC fan connected with the combustion chamber. Main controller; the cold water flowing out of the water inlet pipe of the gas water heater first enters the secondary heat exchanger for heat exchange, and the water flowing out of the secondary heat exchanger enters the primary heat exchanger for heating; There is a flue gas circulation passage connecting the secondary heat exchanger and the combustion chamber, and an electric control air valve for controlling the opening of the passage is provided on the flue gas circulation passage, and the electric control air valve is connected with the main controller. In actual work, a part of the flue gas that has been heat-exchanged and cooled is brought into the combustion chamber through the flue gas circulation channel and the electric control valve, so as to reduce the temperature of the combustion chamber and the oxygen concentration in the diluted mixed gas, which not only improves the hot water efficiency, but also reduces emissions of nitrogen oxides.

Description

A gas water heater with flue gas circulation system

technical field

The utility model relates to the technical field of gas water heaters, in particular to a gas water heater with a flue gas circulation system.

Background technique

A gas water heater is a gas appliance that uses gas as a fuel to transfer heat to cold water flowing through a heat exchanger through combustion heating to achieve the purpose of preparing hot water. Existing gas water heaters will produce _NOx during operation, especially the amount of _NOx generated under high load combustion state will increase significantly. However, in the prior art, most of the flue gas produced by the gas water heater is directly discharged into the air, causing air pollution, which is not enough for energy saving and emission reduction.

Contents of the invention

Aiming at the defects existing in the prior art, the purpose of the utility model is to provide a gas water heater with high energy utilization rate and low nitrogen oxide emission.

In order to achieve the above object, the utility model adopts the following technical solutions.

A gas-fired water heater with a flue gas circulation system, comprising: a combustion chamber, a strong blowing DC fan connected to the combustion chamber, a primary heat exchanger, a secondary heat exchanger, and a main controller connected to the strong blowing DC fan; The cold water flowing out of the water inlet pipe of the gas water heater first enters the secondary heat exchanger for heat exchange, and the water flowing out of the secondary heat exchanger enters the primary heat exchanger for heating; The flue gas circulation channel connecting the stage heat exchanger and the combustion chamber is provided with an electronically controlled gas valve for controlling the opening of the channel, and the electrically controlled gas valve is connected with the main controller.

As an improvement, the strong blower DC fan is connected to the bottom of the combustion chamber, the flue gas guide port of the flue gas circulation channel is set on one side of the secondary heat exchanger, the flue gas outlet of the flue gas circulation channel is connected to the strong blower The air outlet of the DC fan is connected.

As an improvement, both the primary heat exchanger and the secondary heat exchanger are installed above the combustion chamber and arranged sequentially from bottom to top.

During actual work, the main controller changes the opening of the electric control air valve according to the speed of the strong blower DC fan. The greater the speed of the strong blower DC fan, the greater the opening of the electric control air valve. When the speed reaches the maximum, the opening of the electric control air valve also reaches the maximum, and when the speed of the strong drum DC fan reaches the minimum, the electric control air valve closes.

The beneficial effects of the utility model are:

1. Through the flue gas circulation channel and the electronically controlled gas valve, a part of the flue gas that has been heat-exchanged and cooled is brought into the combustion chamber to dilute the oxygen concentration in the mixed gas, which not only improves the efficiency of hot water, but also reduces the emission of nitrogen oxides.

2. Since the flue gas introduced into the air outlet of the strong blower DC fan is the flue gas after cooling, it can effectively avoid the knocking and deflagration phenomenon caused by the backflow of high temperature and high pressure flue gas, which is safe and reliable. The uncooled flue gas is usually as high as hundreds of degrees. When it is directly introduced into the flue gas circulation channel, there will be a danger of premature ignition. At the same time, the gas with too high temperature will knock when it ignites.

3. The opening of the electronically controlled air valve is changed according to the speed of the strong blower DC fan, and the amount of flue gas entering the combustion chamber is adjusted in real time, thereby changing the temperature and oxygen content during combustion, which can more efficiently suppress the emission of nitrogen oxides generate.

Description of drawings

Fig. 1 shows the structural diagram of the gas water heater provided by the utility model.

Explanation of reference signs:

1: Combustion chamber, 2: Strong blower DC fan, 3: Primary heat exchanger, 4: Secondary heat exchanger, 5: Flue gas circulation channel, 6: Electric control valve, 7: Main controller.

detailed description

In order to facilitate those skilled in the art to better understand the essence of the utility model, the specific implementation of the utility model will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, a gas water heater with a flue gas circulation system includes: a combustion chamber 1, a strong direct current fan 2 connected to the combustion chamber 1, a primary heat exchanger 3, and a secondary heat exchanger 4. The flue gas circulation channel 5 connected between the secondary heat exchanger 4 and the combustion chamber 1, the electric control valve 6 arranged on the flue gas circulation channel 5 to control the opening of the channel, and the strong blower DC fan 2, the electric control The air valve 6 is connected to the main controller 7.

Wherein, the strong direct current fan 2 is connected to the bottom of the combustion chamber 1 . Both the primary heat exchanger 3 and the secondary heat exchanger 4 are installed above the combustion chamber 1 and arranged sequentially from bottom to top. The flue gas guide port of the flue gas circulation channel 5 is arranged on the right side of the secondary heat exchanger 4 , and the flue gas outlet of the flue gas circulation channel 5 communicates with the air outlet of the strong blowing DC fan 2 .

The working principle of the gas water heater with flue gas circulation system provided in this embodiment is as follows:

When the gas water heater is working and burning, the secondary heat exchanger 4 first exchanges heat with the cold water in the water inlet pipe of the gas water heater, and the hot water after heat exchange enters the primary heat exchanger 3 for heating and then flows out. When the strong blower DC blower 2 is running at high speed, the gas water heater is burning under high load. At this time, the main controller 7 controls the electric control gas valve 6 to open, and guides part of the flue gas into the flue gas circulation channel 5, and the flue gas is diluted and mixed in the strong In the gas blown by the DC blower, the oxygen concentration is reduced and the formation of nitrogen oxides _NOx is suppressed. When the gas water heater is burning under low load, the speed of the strong blower DC 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 gas valve is closed and no longer guides the flue gas into combustion chamber.

A gas water heater with a flue gas circulation system provided in this embodiment has the following two advantages: 1) The cold water is heated by high-temperature flue gas and then enters the primary heat exchanger for heating, double heating, and the efficiency of hot water is improved. 2) After heat exchange, the flue gas temperature is greatly reduced, and the flue gas returns to the combustion chamber without detonation. And when guiding the flue gas backflow, the return flow is controlled by the electric control air valve. The electric control air valve judges the size of the combustion load of the whole machine through the speed of the strong blower DC fan. In addition to being able to open and close, it can also adjust the opening to make the mixing The gas burns more fully. When burning under high load, the electronically controlled gas valve opens and reaches the maximum opening; when the combustion load decreases, the speed of the strong blower DC fan slows down, and the opening of the electronically controlled gas valve becomes smaller; when burning at the lowest load, the electronically controlled gas valve The valve is closed and no longer guides the flue gas to flow back. This form of control can more effectively suppress the formation of nitrogen oxides.

The above specific embodiments have described the essence of the utility model in detail, but the protection scope of the utility model cannot be limited by this. Obviously, under the enlightenment of the essence of the present invention, those skilled in the art can also make many improvements and modifications, such as setting a condensation heat exchange chamber connected to the combustion chamber, and the secondary heat exchanger is arranged in the condensation heat exchange chamber. cavity etc. It should be noted that these improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims (3)

1. A gas water heater with a flue gas circulation system, including: a combustion chamber, a strong blower DC fan connected to the combustion chamber, a primary heat exchanger, a secondary heat exchanger, and a main control unit connected to the strong blower DC fan The cold water flowing out of the water inlet pipe of the gas water heater first enters the secondary heat exchanger for heat exchange, and the water flowing out of the secondary heat exchanger enters the primary heat exchanger for heating; it is characterized in that there is a The flue gas circulation passage connecting the secondary heat exchanger and the combustion chamber is provided with an electric control air valve for controlling the opening of the passage, and the electric control air valve is connected with the main controller. 2. The gas water heater according to claim 1, characterized in that, the strong direct-flow blower is connected to the bottom of the combustion chamber, and the flue gas guide port of the flue gas circulation channel is set on one side of the secondary heat exchanger , the flue gas outlet of the flue gas circulation channel communicates with the air outlet of the strong direct current fan. 3. The gas water heater according to claim 1, characterized in that, the primary heat exchanger and the secondary heat exchanger are installed above the combustion chamber and arranged sequentially from bottom to top.