阅读说明：本技术 燃气灶的预热系统及燃气灶 (Preheating system of gas stove and gas stove ) 是由 苗伟伟 张神洲 朱伟洪 方力 于 2018-05-31 设计创作，主要内容包括：本发明关于一种燃气灶的预热系统及燃气灶。其中所述燃气灶(1)包括至少一个燃烧器(2),所述燃气灶的预热系统(10)包括位于所述燃气灶(1)内、用于将燃气输送至各所述燃烧器(2)的燃气管(30),所述预热系统(10)还包括预热装置(100),所述预热装置(100)设置在至少部分的所述燃气管(30)上,用于加热所述燃气管(30)内流动的燃气,所述预热装置(100)的加热温度沿着燃气的流动方向(G)逐渐降低。所述预热系统可以在不降低燃气灶其他性能的前提下,提高燃气灶的热效率。(The invention relates to a preheating system of a gas stove and the gas stove. The gas stove (1) comprises at least one burner (2), the preheating system (10) of the gas stove comprises gas pipes (30) which are positioned in the gas stove (1) and used for conveying gas to each burner (2), the preheating system (10) further comprises a preheating device (100), the preheating device (100) is arranged on at least part of the gas pipes (30) and used for heating the gas flowing in the gas pipes (30), and the heating temperature of the preheating device (100) is gradually reduced along the flowing direction (G) of the gas. The preheating system can improve the heat efficiency of the gas stove on the premise of not reducing other performances of the gas stove.)

1. Preheating system (10) of a gas burner (1), wherein the gas burner (1) comprises at least one burner (2), the preheating system (10) comprising a gas pipe (30) located within the gas burner (1) for conveying gas to each of the burners (2), characterized in that,

The preheating system (10) further comprises a preheating device (100), wherein the preheating device (100) is arranged on at least part of the fuel gas pipe (30) and used for heating fuel gas flowing in the fuel gas pipe (30), and the heating temperature of the preheating device (100) is gradually reduced along the flowing direction (G) of the fuel gas.

2. The preheating system (10) of a gas range (1) according to claim 1, wherein the heating temperature of the preheating device (100) is linearly decreased along the flow direction (G) of the gas.

3. The preheating system (10) of a gas range (1) according to claim 1, wherein the preheating device (100) comprises a plurality of heating sections (110, 120, 130, 140, 210, 220, 230, 240), and heating temperatures of the plurality of heating sections (110, 120, 130, 140, 210, 220, 230, 240) sequentially decreasing are sequentially distributed in a flow direction (G) of the gas.

4. The preheating system (10) of a gas range (1) according to claim 3, wherein a plurality of the heating sections (110, 120, 130, 140) are connected in parallel with each other.

5. The preheating system (10) of a gas range (1) according to claim 4, wherein the heating sections (110, 120, 130, 140) comprise heating wires, and the heating wires of each heating section (110, 120, 130, 140) are different in material and/or thickness and/or arrangement density.

6. The preheating system (10) of a gas range (1) according to claim 3, further comprising a temperature control device, each heating section (110, 120, 130, 140) corresponds to a preset temperature, and the temperature control device is used for controlling the heating temperature of each heating section (110, 120, 130, 140) to reach and be maintained within the range of the preset temperature corresponding to each heating section (110, 120, 130, 140).

7. The preheating system (10) of a gas range (1) as set forth in claim 3, wherein said plurality of heating sections (210, 220, 230, 240) are formed of one continuous heating wire, and the arrangement density of the heating wires of each of said heating sections (210, 220, 230, 240) is different.

8. The preheating system (10) of a gas range (1) according to any one of claims 1 to 7, wherein the heating temperature of the beginning of the preheating device (100) in the flow direction (G) of the gas ranges from 150 ℃ to 300 ℃, and/or the heating temperature of the end of the preheating device (100) in the flow direction (G) of the gas ranges from 70 ℃ to 150 ℃.

9. The preheating system (10) of a gas range (1) according to any one of claims 1 to 7, further comprising a control device, wherein the gas range (1) comprises a gas nozzle (3), the preheating system (10) further comprises a temperature detection device disposed at a tail end of the gas pipe (30) or a tail end of the preheating device (100) or between the gas pipe (30) and the gas nozzle (3) for detecting a temperature of the preheated gas, and the control device is configured to automatically adjust a heating temperature of the preheating device (100) according to the temperature detected by the temperature detection device.

10. The preheating system (10) according to any one of claims 1 to 7, wherein the gas burner (1) comprises at least one gas valve (4) for regulating the flow of gas to the respective burner (2), the gas pipe (30) comprises a main gas pipe (31) and at least one gas distribution pipe (32), the main gas pipe (31) is used for introducing gas into the gas burner (1) and is connected to the gas valve (4), and the gas distribution pipe (32) is installed between the gas valve (4) and the burner (2); the preheating device (100) is arranged on the main gas pipe (31) and/or on the gas distribution pipe (32).

11. Preheating system (10) according to any one of claims 1 to 7, characterized in that the total length of the preheating device (100) in the flow direction (G) of the combustion gases is greater than or equal to 0.3 m.

12. The preheating system (10) according to any one of claims 1 to 7, wherein the preheating system (10) includes a control switch provided on the gas range (1), and when the control switch is turned on, the preheating device (100) starts heating.

13. Gas burner (1), characterized in that it comprises at least one burner (2) and a preheating system (10) of the gas burner (1) according to any of the previous claims.

14. The gas burner (1) according to claim 12, characterized in that the preheating system (10) is automatically turned on at the same time as the gas burner (1) is turned on and is in an on state for a continuous period of time after the gas burner (1) is turned on; when the time period expires, the preheating system (10) is automatically shut down.

[ technical field ] A method for producing a semiconductor device

The invention relates to the field of gas cookers, in particular to a preheating system of a gas cooker and the gas cooker comprising the preheating system.

[ background of the invention ]

Generally, when a user cooks with a gas range, the user always wants to heat a pot to a certain temperature in a very short time when the gas range is just opened, so as to preheat the pot, and then starts to cook. Because the rated thermal load of the gas stove when leaving the factory is certain, such as 4.0kw, although the user just adopts the maximum fire heating when the gas stove is opened, the purpose that the user wants to finish preheating the pot in a shorter time cannot be realized.

In addition, from a consumer perspective, it is always desirable that the thermal efficiency of the home stove product be as high as possible. From the whole gas stove industry, the national standard (GB30720-2014) domestic gas stove energy efficiency limit value and energy efficiency grade sets an energy efficiency limit value for the heat efficiency of various gas stoves, the energy efficiency grade of the domestic gas stove is divided into three grades, products reaching the first and second grade energy efficiency are energy-saving products, and products not reaching the third grade requirement are not allowed to leave the factory. Therefore, improving the thermal efficiency becomes the focus of research and development and publicity of various gas stove manufacturers.

Taking an embedded atmospheric gas stove as an example, the thermal efficiency of the gas stove is not lower than 63% in order to reach a first-level energy efficiency level. The applicant has found that after the thermal efficiency of the gas burner reaches 63%, many improvements to improve the thermal efficiency of the gas burner bring other problems, such as excessive carbon monoxide (CO) concentration, poor fire transmission, etc. Under the condition of not sacrificing other performances or reducing other indexes, the attempt to improve the heat efficiency of the gas stove is very difficult even by one percentage point.

[ summary of the invention ]

It is an object of the present invention to provide an improved preheating system for gas cookers, which addresses at least one of the above technical problems.

Another object of the present invention is to provide an improved gas range in view of at least one of the above technical problems.

It is still another object of the present invention to provide a preheating system of a gas range, which can improve the thermal efficiency of the gas range without reducing other performances of the gas range, in view of at least one of the above technical problems.

In order to achieve at least one of the above technical objects, the present invention proposes, for example, a technical solution that: the preheating system of the gas stove comprises at least one burner, the preheating system comprises gas pipes which are positioned in the gas stove and used for conveying gas to the burners, the preheating system further comprises a preheating device, the preheating device is arranged on at least part of the gas pipes and used for heating the gas flowing in the gas pipes, and the heating temperature of the preheating device is gradually reduced along the flowing direction of the gas.

the technical scheme can improve the heat efficiency of the gas stove under the condition of not sacrificing other performances or reducing other indexes.

The applicant has also considered that other possibilities of the preheating device, such as the preheating device heating the gas with the same temperature along the flow direction of the gas, present the following problems: if the temperature of the preheating device is set too low, it is difficult to achieve an ideal preheating temperature on a limited heating path in the gas stove, and the effect of improving the heat efficiency of the gas stove is slight. If the temperature of the preheating device is set too high, energy waste is easily caused, and the excessive gas temperature exceeds the working temperature range of some parts (such as an electromagnetic valve) of the gas stove, so that the parts are easily damaged. If the preheating device adopts a relatively middle temperature for heating, the temperature of the preheated fuel gas is difficult to stabilize. Because the gas-cooker is inevitable in the use and is adjusted different gear or firepower, and under different gear or firepower, the gas velocity of flow in the gas pipe changes greatly, the gas passes through preheating device under different velocity of flow, and the temperature that reaches has very big difference.

In the above technical scheme of the invention, because the heating temperature of the preheating device is gradually reduced along the flowing direction of the fuel gas, if the flow rate of the fuel gas is very low, the fuel gas can reach a higher temperature at the front section of the preheating device, the fuel gas can exchange heat with the preheating device at the rear section of the preheating device, the heat of the fuel gas can be transferred to the preheating device, and finally, the temperature of the fuel gas cannot be too high after passing through the preheating device. If the gas flow rate is large, the ideal temperature cannot be achieved at the front section of the preheating device, and then the gas can be continuously heated at the rear section of the preheating device, so that the ideal temperature is achieved. Therefore, according to the technical scheme of the invention, the temperature of the preheated fuel gas can be better controlled, even if the fuel gas is at different flow rates, the temperature of the preheated fuel gas can be more stable, and compared with the condition that the preheating device adopts the same temperature for heating along the flow direction of the fuel gas, the scheme of the invention has better stability.

Wherein, the preheating device among the above-mentioned technical scheme can adopt the heater strip (also called heating wire or heater) to twine on the gas pipe, for example iron chromium aluminium heating wire, nickel chromium heating wire or carbon fiber heating wire.

In an embodiment of the invention, the preheating device includes a carbon fiber heating wire. Compared with other heating wires, the carbon fiber heating wire has the characteristic of no spark or electric arc when the wire is broken, which is very important for the gas stove, so that the fire can be effectively prevented, and the safety of the gas stove is enhanced. Because the gas stove is used in the year-round and month-old process, a small amount of gas is gathered in the gas stove or the cupboard, and the heating wire is safer.

The preheating device may also employ a heating film, such as a Silicone Rubber heating film (Silicone Rubber Heaters), covering the gas pipe. The silicon rubber heating film mainly comprises a nickel-chromium alloy heating wire and a silicon rubber high-temperature insulating material. It has the advantages of fast heating, uniform temperature and difficult aging.

It should be noted that "the heating temperature of the preheating device gradually decreases along the flow direction of the combustion gas" may include a case of intermittent decrease, and also includes a case of continuous or stepless decrease. Therefore, the "heating temperature of the preheating device gradually decreases along the flowing direction of the fuel gas", the whole preheating device is viewed macroscopically, because for the intermittent decrease situation, there may be a case that the heating temperature does not change along the flowing direction of the fuel gas for one of the heating sections, but the heating temperature gradually decreases intermittently for the whole preheating device. For the case of stepless reduction of the heating temperature, one example is to wind the heating wire on the fuel gas pipe, and the heating wire is wound from dense to sparse along the flow direction of the fuel gas, and there are other ways to realize stepless reduction of the heating temperature of the preheating device along the flow direction of the fuel gas, which are not listed here.

In a possible embodiment of the invention, the heating temperature of the preheating device decreases linearly along the flow direction of the combustion gas. Thus, the manufacture of the preheating device and the control of the heating temperature are more convenient.

In a possible embodiment of the present invention, the preheating device includes a plurality of heating sections, and heating temperatures of the plurality of heating sections sequentially decreasing in a flowing direction of the fuel gas. Multiple heating zones may be connected in parallel with each other, with the current supplied in stages, providing greater current flow over the heating zones requiring higher heating temperatures. Alternatively, a plurality of heating sections are connected in series, and the arrangement density of the heating bodies per unit area of each heating section is different.

In a possible embodiment of the invention, a plurality of heating sections are connected in parallel. By the arrangement, the heating temperature of each heating section can be controlled more conveniently, the maintenance and the replacement are convenient, and the maintenance and the replacement cost is lower.

In a possible embodiment of the present invention, the heating sections include heating wires, and the heating wires of each heating section are different in material and/or thickness and/or arrangement density. The material of the heating wire influences the resistivity, and the thickness of the heating wire influences the sectional area. The arrangement density of the heater wires is understood to include not only the arrangement density in the transverse and longitudinal directions but also the arrangement in the thickness direction.

In a possible embodiment of the present invention, the preheating system of the gas stove further includes a temperature control device, each of the heating sections corresponds to a preset temperature, and the temperature control device is configured to control the heating temperature of each of the heating sections to reach and be kept within a range of the preset temperature corresponding to each of the heating sections. Generally, when the gas stove leaves a factory, the preset temperature of each heating section is determined, and the temperature control device controls each heating section of the preheating device to achieve an ideal temperature and an energy-saving effect.

In one possible embodiment of the present invention, the plurality of heating segments are formed by one continuous heating wire, and the arrangement density of the heating wires of the heating segments is different.

In a possible embodiment of the invention, the heating temperature of the preheating device at the beginning in the flow direction of the fuel gas ranges from 150 ℃ to 300 ℃ (both inclusive), and/or the heating temperature of the preheating device at the end in the flow direction of the fuel gas ranges from 70 ℃ to 150 ℃ (both inclusive).

In a possible embodiment of the present invention, the heating temperature of the preheating device at the beginning in the flowing direction of the fuel gas ranges from 170 ℃, and the heating temperature of the preheating device at the end in the flowing direction of the fuel gas ranges from 90 ℃.

When the heating temperature of the preheating device at the starting end in the flowing direction of the fuel gas is 170 ℃, the heating temperature of the preheating device at the tail end in the flowing direction of the fuel gas is 90 ℃. The total length of the preheating device is 0.4 m. The test shows that the gas reaches 70 ℃ after being heated by the preheating device, and compared with the gas stove under the condition that the preheating device is closed, the heat efficiency of the gas stove after the preheating device is opened is improved by two percentage points (absolute numerical value).

In one possible embodiment of the invention, the heating temperature of the end of the preheating device in the flow direction of the combustion gas is 20 ℃ higher than the temperature reached by the combustion gas after passing through the preheating device.

In a possible embodiment of the present invention, the preheating system of the gas stove further includes a control device, the gas stove includes a gas nozzle, the preheating system further includes a temperature detection device, the temperature detection device is disposed at the tail end of the gas pipe or the tail end of the preheating device or between the gas pipe and the gas nozzle, and is configured to detect the temperature of the preheated gas, and the control device is configured to automatically adjust the heating temperature of the preheating device according to the temperature detected by the temperature detection device.

Therefore, the improved scheme can realize automatic adjustment of the heating temperature of the preheating device, so that the gas reaches an ideal temperature after being preheated, the preheating device is more intelligent and automatic, and the preheating temperature is more accurately controlled. Of course, the above-mentioned solution can be implemented without a large number of experiments and software or circuits designed according to experimental data, thereby realizing automatic adjustment.

In a possible embodiment of the present invention, the gas burner comprises at least one gas valve for regulating the flow of gas supplied to the corresponding burner, the gas pipe comprises a main gas pipe and at least one gas distribution pipe, the main gas pipe is used for introducing gas into the gas burner and is connected to the gas valve, and the gas distribution pipe is installed between the gas valve and the burner; the preheating device is arranged on the main gas pipe and/or the gas distribution pipe.

In a possible embodiment of the invention, the total length of the preheating device in the flow direction of the combustion gas is greater than or equal to 0.3 m. Otherwise, the length of the preheating device in the flowing direction of the fuel gas is too short, so that an ideal preheating effect is difficult to achieve, and the effect of improving the heat efficiency is not obvious.

In a possible embodiment of the invention, the total length of the preheating device in the flow direction of the combustion gas is greater than or equal to 0.4 m. Therefore, after the fuel gas passes through the heating path with a certain length, the temperature of the preheated fuel gas is more stable, and the improvement of the heat efficiency of the combustor is obviously facilitated.

In a possible embodiment of the present invention, the preheating system includes a control switch disposed on the gas stove, and the preheating device starts heating when the control switch is turned on. Through the embodiment, the technical problem mentioned in the background technology can be solved, namely, a user always hopes that the cooker is heated to a certain temperature in a shorter time when the gas stove is just opened, thereby achieving the purpose of shortening the time for preheating the cooker. The user can start the control switch before the gas stove is opened, so that the actual thermal efficiency of the burner is improved to be higher than the nominal thermal efficiency for heating, and the purpose that the user wants to finish preheating the cooker in a shorter time can be realized.

In accordance with another technical purpose of the present invention, there is also provided a gas range, for example, including at least one burner and a preheating system of the gas range according to any one of the above embodiments.

in a possible embodiment of the present invention, the preheating system is automatically turned on while the gas range is being turned on, and is in an on state for a continuous period of time after the gas range is turned on; when the time period expires, the preheating system is automatically closed. The time period may range, for example, from 3 to 15 minutes, and in one embodiment of the present invention, the time period is 15 minutes. Therefore, the preheating system is automatically started when the gas stove is opened, heats the gas within a time period after the gas stove is opened, and automatically closes after the time period expires. The burner can achieve higher thermal efficiency without changing the thermal load of the burner, sacrificing other performance or reducing other indicators (such as CO emissions), thereby making the user's usual needs more efficient and shorter in time, such as preheating pots, melting food, boiling water, fast roasting meat or stir-frying. Of course, in one embodiment of the present invention, the length of the time period may be selected by the user.

[ description of the drawings ]

Fig. 1 is a schematic view of a preheating system of a gas range according to an embodiment of the present invention;

Fig. 2 is a schematic view of a preheating system of a gas range according to another embodiment of the present invention;

Fig. 3 is a schematic view of a gas range according to an embodiment of the present invention.

Reference numerals:

1-gas range; 2-a burner; 3-a gas nozzle; 4-a gas valve; 5-a bottom shell; 10-a preheating system; 30-a gas pipe; 31-main trachea; 32-gas distribution pipe; 40-a cable; 50-a power supply; 100-a preheating device; 110, 120, 130, 140, 210, 220, 230, 240-heating section; g-the flow direction of the gas.

[ detailed description ] embodiments

In order to further understand the objects, structures, features and functions of the present invention, the following embodiments are described in detail.

Referring to fig. 1 and fig. 2, fig. 1 is a schematic diagram of a preheating system of a gas stove according to an embodiment of the present invention; fig. 2 is a schematic view of a preheating system of a gas range according to another embodiment of the present invention.

Wherein the gas range 1 comprises at least one burner 2 (shown in fig. 3), the preheating system 10 comprises a gas pipe 30 located within the gas range 1 for delivering gas to each burner 2. The preheating system 10 further includes a preheating device 100, the preheating device 100 is disposed on at least a portion of the gas pipe 30 for heating the gas flowing in the gas pipe 30, and the heating temperature of the preheating device 100 is gradually decreased along a flowing direction G (dashed line with arrow in the figure) of the gas.

The preheating device 100 shown in fig. 1 includes four heating sections, indicated by reference numerals 110, 120, 130 and 140, respectively. The total heating length of the four heating sections together was 0.4 m. The heating temperatures of the four heating sections 110, 120, 130, 140 sequentially distributed in the flow direction G of the fuel gas are sequentially decreased, and are linearly decreased in the flow direction G of the fuel gas.

The heating temperature of the heating section 110 at the beginning in the flow direction G of the fuel gas is 170 ℃, the heating temperature of the heating section 120 is 140 ℃, the heating temperature of the heating section 130 is 110 ℃, and the heating temperature of the heating section 140 at the end in the flow direction G of the fuel gas is 90 ℃. Each of the heating sections 110, 120, 130, 140 includes a heating wire wound around the gas pipe 30, and the heating sections are connected in parallel to each other by a cable 40 and then connected to the power supply 50. The connection of the power source 50 may be made by plugging a plug of the gas range into a socket of the kitchen.

the heating sections correspond to different heating temperatures, and may be implemented in many ways, for example, the material of the heating wires of the heating sections is different, or the thickness of the heating wires of the heating sections is different, or the arrangement density of the heating wires of the heating sections is different. Of course, the different approaches described above can be used in combination with each other.

The preheating system 10 includes a control switch provided on the gas range 1, and the preheating device 100 starts heating when the control switch is turned on. The user can selectively turn on the preheating device through the control switch.

In a further improved embodiment of the present invention, the preheating system 10 of the gas stove 1 further includes a temperature control device, and each of the heating sections 110, 120, 130, and 140 corresponds to a preset temperature, i.e. the preset temperature corresponding to the heating section 110 is 170 ℃, the preset temperature corresponding to the heating section 120 is 140 ℃, the preset temperature corresponding to the heating section 130 is 110 ℃, and the preset temperature corresponding to the heating section 140 is 90 ℃. The temperature control device is used for controlling the heating temperature of each heating section to reach and keep in the range of the corresponding preset temperature of each heating section.

Referring now to fig. 2, the preheating arrangement of fig. 2 also includes four heating sections, generally indicated at 210, 220, 230 and 240. The heating temperatures of the four heating sections 210, 220, 230, 240 sequentially distributed in the flow direction G of the combustion gas are sequentially decreased. Unlike the previous embodiment, in this embodiment, the plurality of heating sections are connected in series to each other and then connected to the power supply 50, and four heating sections 210, 220, 230, and 240 are formed of one continuous heating wire, and the arrangement density of the heating wires of each heating section is different. As shown in fig. 2, the heating wires of the heating sections are distributed in sequence along the flowing direction G of the fuel gas, and the arrangement density of the heating wires is from dense to sparse. Thereby, a sequential reduction of the heating temperature of the four heating sections 210, 220, 230, 240, which are sequentially distributed in the flow direction G of the combustion gas, can be achieved.

in this embodiment, the heating temperature of the heating section 210 at the beginning of the flowing direction G of the fuel gas is 200 ℃, the heating temperature of the heating section 220 is 160 ℃, the heating temperature of the heating section 230 is 120 ℃, and the heating temperature of the heating section 240 at the end of the flowing direction G of the fuel gas is 80 ℃.

In fact, the gas pipe 30 in the gas range includes a main gas pipe and a branch gas pipe, and as will be described in detail later, the preheating device 100 may be disposed on the main gas pipe or on the branch gas pipe; it is also possible that both the main gas pipe and the branch gas pipe are provided with preheating devices, as long as the total length of the preheating device 100 in the flowing direction G of the fuel gas is greater than or equal to 0.3 m. The heating temperature of the initial end of the preheating device 100 in the flowing direction G of the fuel gas is in the range of 150-300 ℃, and the heating temperature of the tail end of the preheating device 100 in the flowing direction G of the fuel gas is in the range of 70-150 ℃, so that the heating device has obvious help for improving the heat efficiency of the gas stove.

In another improved embodiment of the present invention, the preheating system 10 of the gas range 1 further comprises a control device, the gas range 1 comprises a gas nozzle 3 (shown in fig. 3), the preheating system 10 further comprises a temperature detection device disposed at the tail end of the gas pipe 30 or at the tail end of the preheating device 100 or between the gas pipe 30 and the gas nozzle 3 for detecting the temperature of the preheated gas, and the control device is configured to automatically adjust the heating temperature of the preheating device 100 according to the temperature detected by the temperature detection device.

Referring to fig. 3, fig. 3 is a schematic view of a gas stove according to an embodiment of the invention.

The gas range 1 comprises two burners 2 and a preheating system 10. The preheating system 10 may employ the preheating system described in any of the previous embodiments. Although the preheating device 100 in fig. 3 does not correspondingly illustrate multiple heating sections, this does not mean that the preheating device 100 may not include multiple heating sections. The gas burner 1 further comprises a bottom shell 4 and two gas valves 4 located inside the bottom shell 4, each gas valve 4 being adapted to regulate the flow of gas to the respective burner 2. The bottom shell 5 is covered with a panel (the panel is removed in fig. 3 for clarity of showing the structure related to the invention). The bottom shell 5 of the present embodiment defines the inner and outer limits of the gas burner 1, being located inside the bottom shell 5, referred to as being located inside the gas burner. The preheating system 10 includes a gas pipe 30 located within the gas range 1 for delivering gas to each burner 2, i.e., the gas pipe 30 is illustrated as being located within the bottom case 5.

In this embodiment, the gas pipe 30 includes a main gas pipe 31 and four gas branch pipes 32, the main gas pipe 31 is used for introducing gas into the gas range 1 and is connected to the gas valve 4, and the gas branch pipes 32 are installed between the gas valve 4 and the burner 2. Wherein, every two gas distribution pipes 32 respectively supply inner ring gas and outer ring gas to a burner 2 correspondingly, and the inner ring gas and the outer ring gas on the burner 2 are ignited to form inner ring flame and outer ring flame respectively.

The preheating device 100 of the present embodiment is provided only on the main air duct 31. Because the main air pipe 31 has a simple pipe structure, is L-shaped, and has no too many bends and corners, the preheating device 100 is arranged on the main air pipe 31, and the realization is more convenient and easy. In addition, the preheating device 100 is provided only in the main gas duct 31, and it is possible to preheat the gas supplied to any one of the burners.

The preheating system 10 is automatically turned on while the gas range 1 is being opened, and is in an on state for a continuous period of time after the gas range 1 is turned on; when the time period expires, the preheating system 10 is automatically shut down. The time period of this example was 10 minutes.

The preheating system 10 of the embodiment shown in fig. 1 is adopted in a gas range with a heat load of 5kw, wherein the preheating device 100 is provided on the main gas pipe 31 with a diameter of 14mm, and the total heating length of the heating sections is 0.4 m. The gas flow rate in the main gas pipe 31 was 0.96m/s, and the gas temperature was detected to be 70 ℃ by the gas flow rate between one of the branch gas pipes 32 and the gas nozzle 3. According to measurement, under the condition that the preheating device 100 is started, the heat efficiency of the gas stove is improved by 2 percent (absolute numerical value) compared with the same gas stove without the preheating device 100, and the heat efficiency is difficult to achieve under the condition that other performances are not sacrificed after the gas stove achieves first-level energy efficiency.

Therefore, compared with the expensive research and development cost and production cost which are invested for changing the structure, the pipeline and the like of the burner in order to improve the heat efficiency of the gas stove, the embodiment of the invention can realize the improvement of the heat efficiency of the gas stove at a low cost, and the other performances of the gas stove are not changed, so that the stability is good.

The various embodiments of the individual components described in connection with fig. 1 to 3 may be combined with each other in any given way to achieve the advantages of the invention.

The present invention has been described in relation to the above embodiments, which are only exemplary of the implementation of the present invention. It should be noted that the disclosed embodiments do not limit the scope of the invention. Rather, it is intended that all such modifications and variations be included within the spirit and scope of this invention.