Flame monitoring device and gas water heater containing the same

Abstract

The present invention discloses a flame monitoring device and a gas water heater including the same. The flame monitoring device is arranged on the heat exchanger of the gas water heater. The flame monitoring device includes a photoresistor. The photoresistor is arranged near the heat dissipation coil of the gas water heater. Through the flame monitoring device disclosed by the present invention and the gas water heater including the same, when there is a flame in the combustion chamber of the heat exchanger of the gas water heater, the combustion chamber will be illuminated by the flame, and the light will be irradiated onto the photoresistor through the mica sheet, causing the resistance value of the photoresistor to change. The controller can determine whether there is a flame in the combustion chamber by detecting the resistance value of the photoresistor. This flame detection method using light intensity is more reliable than the general flame ion sensing method. At the same time, arranging the photoresistor on the heat dissipation coil can dissipate heat from the photoresistor through the heat dissipation coil, preventing it from failing due to heat, and having higher stability and accuracy.

Description

Technical Field

[0001] The present invention relates to the field of gas water heaters, and in particular to a flame monitoring device and a gas water heater comprising the same. Background Art

[0002] During operation, the gas water heater needs to constantly detect whether there is a flame in the combustion chamber. If the gas valve is open but there is no flame, it means that there is a failure to ignite or a flameout. If the gas valve is not open but a flame is detected, it means a false fire failure. Therefore, flame detection is very important for gas water heaters. At present, the flame sensing method of gas water heaters is basically realized by using flame ionization sensing needles, which are generally arranged on the combustion chamber box, such as Figure 1 . The principle is that because the flame has unidirectional conductivity, the controller of the machine can determine whether there is a flame by applying voltage to the flame sensing needle and then detecting whether there is current passing through. The presence of current indicates the presence of a flame, and the absence of current indicates the absence of a flame. However, in addition to being affected by the intensity of the flame, this current is also affected by the resistance of the current sensing path. The greater the path resistance, the smaller the sensed current. Since the flame sensing needle has been in a high-temperature environment of gas and flame, an oxide layer and an impurity layer are easily formed on the flame sensing needle after a long period of use of the water heater. The formation of these substances greatly reduces the current obtained during the flame monitoring process, and may eventually be less than the threshold for effective judgment. This leads to the problem of flame sensing needle failure. At the same time, in order for the flame sensing needle to adapt to flames of different intensities, the height of the sensing needle from the fire hole surface needs to be strictly controlled. Deviations in this height can easily lead to flame sensing failure. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects in the prior art that the flame sensing needle of the gas water heater easily forms an oxide layer and an impurity layer, resulting in flame sensing needle failure and highly stringent requirements, and provide a flame monitoring device and a gas water heater containing the same.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] A flame monitoring device for a gas water heater is characterized in that the flame monitoring device is arranged on a heat exchanger of the gas water heater and comprises a photoresistor, which is arranged close to a heat dissipation coil of the gas water heater.

[0006] In this solution, the above structure is adopted. When there is a flame in the combustion chamber of the gas water heater heat exchanger, the combustion chamber will be lit by the flame (the combustion chamber is composed of the upper part of the combustion chamber box and the lower part of the heat exchanger). The light is irradiated onto the photoresistor through the mica sheet, causing the resistance of the photoresistor to change. The controller can then determine whether there is a flame in the combustion chamber by detecting the resistance of the photoresistor. This method of flame detection using light intensity is more reliable than the general flame ion sensing method. The inspection components do not need to be corroded by high temperature and impurities for a long time, and can adapt to flame conditions of various intensities. It is not easy to cause flame monitoring failure. This makes flame monitoring more accurate and stable. At the same time, placing the photoresistor on the heat dissipation coil can dissipate heat from the photoresistor through the heat dissipation coil to prevent it from failing due to heat, and the stability and accuracy are higher.

[0007] Preferably, the photoresistor is separated from the interior of the heat exchanger by a heat insulation sheet, and the heat insulation sheet is light-transmissive.

[0008] In this solution, the above structure is adopted, and the heat insulation sheet can transmit light while also isolating the heat inside the heat exchanger, thereby preventing the photoresistor from being aged due to heat.

[0009] Preferably, there is a gap between the photoresistor and the thermal insulation sheet.

[0010] In this solution, the above structure is adopted, and an air layer is formed in the gap between the photoresistor and the heat insulation sheet, which further isolates the photoresistor from heat exchange inside the heat exchanger to prevent the photoresistor from failing due to heat.

[0011] Preferably, the thermal insulation sheet is a mica sheet.

[0012] In this solution, the above structure is adopted, and the mica sheet has the characteristics of high temperature resistance and strong light transmittance.

[0013] Preferably, the flame monitoring device also includes a light shield, which includes a first open surface and a second open surface, the first open surface is arranged to fit the surface of the heat exchanger, and the second open surface of the light shield is arranged to fit the upper surface of the heat dissipation coil. The light shield and the surface of the heat exchanger and the upper surface of the heat dissipation coil are arranged to form a closed cavity, and the photoresistor is arranged in the closed cavity.

[0014] In this solution, the above structure is adopted, the light shield contacts the heat exchanger and the heat dissipation coil and seals the photoresistor therein, which can prevent light leakage from causing misjudgment of the photoresistor.

[0015] Preferably, the second open surface includes an arc-shaped groove having a shape matching the upper surface of the heat dissipation coil, and the heat dissipation coil is embedded in the arc-shaped groove.

[0016] In this solution, the above structure is adopted, and the light shield and the heat dissipation coil are nested and connected, which has a better sealing effect and is less likely to leak light.

[0017] Preferably, the flame monitoring device further comprises a flat sealing gasket and a coil sealing gasket, wherein the flat sealing gasket is arranged on the first open surface, and the coil sealing gasket is arranged on the second open surface.

[0018] In this solution, the above structure is adopted, and a flat sealing gasket and a coil sealing gasket are set at the connection to fill the gap at the connection and prevent light leakage from causing misjudgment of the photoresistor.

[0019] Preferably, a heat dissipation hole is provided in the middle of the coil sealing gasket.

[0020] In this solution, the above structure is adopted, the coil sealing gasket is attached to the heat dissipation coil, and the heat dissipation holes are opened on the coil sealing gasket without affecting the heat dissipation effect of the heat dissipation coil on the inside of the sunshade.

[0021] A gas water heater comprises a heat exchanger, a heat dissipation coil arranged on the surface of the heat exchanger and the flame monitoring device as described above.

[0022] In this solution, the above structure is adopted. When there is a flame in the combustion chamber of the gas water heater heat exchanger, the combustion chamber will be lit by the flame (the combustion chamber is composed of the upper part of the combustion chamber box and the lower part of the heat exchanger). The light is irradiated onto the photoresistor through the mica sheet, causing the resistance of the photoresistor to change. The controller can then determine whether there is a flame in the combustion chamber by detecting the resistance of the photoresistor. This method of flame detection using light intensity is more reliable than the general flame ion sensing method. The inspection components do not need to be corroded by high temperature and impurities for a long time, and can adapt to flame conditions of various intensities. It is not easy to cause flame monitoring failure. This makes flame monitoring more accurate and stable. At the same time, placing the photoresistor on the heat dissipation coil can dissipate heat from the photoresistor through the heat dissipation coil to prevent it from failing due to heat, and the stability and accuracy are higher.

[0023] Preferably, a light-transmitting window is provided on the surface of the heat exchanger, and the flame monitoring device is arranged outside the heat exchanger at a position facing the light-transmitting window.

[0024] In this solution, the above structure is adopted, so that the photoresistor can detect the flame without being affected by the internal temperature of the heat exchanger.

[0025] The positive progressive effect of the present invention is that when there is a flame in the combustion chamber of the gas water heater heat exchanger, the combustion chamber will be lit by the flame (the combustion chamber is composed of the upper part of the combustion chamber box and the lower part of the heat exchanger), and the light will be irradiated onto the photoresistor through the mica sheet, causing the resistance of the photoresistor to change. The controller can then determine whether there is a flame in the combustion chamber by detecting the resistance of the photoresistor. This method of flame detection using light intensity is more reliable than the general flame ion sensing method. The inspection components do not need to be corroded by high temperature and impurities for a long time, and can adapt to flame states of various intensities. It is not easy to cause flame monitoring failure. This makes flame monitoring more accurate and stable. At the same time, arranging the photoresistor on the heat dissipation coil can dissipate heat from the photoresistor through the heat dissipation coil to prevent it from failing due to heat, and the stability and accuracy are higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of a gas water heater according to an embodiment of the present invention.

[0027] Figure 2 Schematic diagram of the structure of a heat exchanger and a flame monitoring device according to an embodiment of the present invention.

[0028] Figure 3 Schematic diagram of the explosion structure of the flame monitoring device according to an embodiment of the present invention.

[0029] Figure 4 Schematic diagram of the structure of a flame monitoring device according to an embodiment of the present invention.

[0030] Figure 5 Schematic diagram of the cross-sectional structure of a flame monitoring device according to an embodiment of the present invention.

[0031] Figure 6 Schematic diagram of the structure of the coil sealing gasket according to an embodiment of the present invention.

[0032] Description of reference numerals:

[0033] Heat exchanger 10

[0034] Combustion chamber box 20

[0035] Controller 30

[0036] Fan 40

[0037] Flame monitoring device 100

[0038] Thermal insulation sheet 110

[0039] Press plate 120

[0040] Photoresistor 130

[0041] Flat gasket 141

[0042] Coil gasket 142

[0043] Thermal through hole 1421

[0044] Lens hood 150

[0045] First open surface 151

[0046] Second open surface 152

[0047] Arc groove 153

[0048] Resistor mounting plate 160

[0049] Air layer 170 DETAILED DESCRIPTION

[0050] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0051] like Figure 1 、 2 As shown, this embodiment provides a gas water heater, which primarily comprises a fan 40, a heat exchanger 10, a combustion chamber box 20, a gas proportional valve, a controller 30, and a flame monitoring device 100. The combustion chamber box 20 eliminates the flame sensor typically found in conventional water heaters. Instead, the flame monitoring device 100, mounted on the heat exchanger 10, monitors the flame during combustion. The heat exchanger 10 is provided with a heat dissipation coil, and the flame monitoring device 100 is mounted on the heat dissipation coil.

[0052] The flame monitoring device 100 of this embodiment detects flames through photosensitivity, specifically through the photoresistor 130. When there is a flame in the combustion chamber of the gas water heater, the combustion chamber will be lit by the flame (the combustion chamber is composed of the upper part of the combustion chamber box 20 and the lower part of the heat exchanger 10), and the light will be irradiated onto the photoresistor 130, causing the resistance of the photoresistor 130 to change. The controller 30 can then determine whether there is a flame in the combustion chamber by detecting the resistance of the photoresistor 130. This method of flame detection using light intensity is more reliable than the general flame ion sensing method. The inspection components do not need to be corroded by high temperature and impurities for a long time, and can adapt to flame states of various intensities. It is not easy to cause the phenomenon of flame monitoring failure.

[0053] The heat dissipation coil in this embodiment is a common structure used in conventional hot water heaters. Its primary function is to direct cold water flowing into the water heater to the metal shell surrounding the combustion chamber, where it is coiled to reduce the temperature of the metal shell. Specifically, the heat dissipation coil is a spiral structure installed on the outer surface of the heat exchanger 10 and the combustion chamber.

[0054] Gas water heaters employing this flame monitoring device 100 avoid the drawbacks of placing a flame sensor needle inside the combustion chamber, which can lead to monitoring failure and require high accuracy, thereby making flame monitoring more accurate and stable. Furthermore, placing the photoresistor 130 on the heat dissipation coil allows the heat dissipation of the photoresistor 130 to be dissipated through the heat dissipation coil, preventing thermal failure and improving stability and accuracy.

[0055] like Figure 3 As shown, a light-transmitting window is provided on the surface of the heat exchanger 10, and the flame monitoring device 100 is arranged outside the heat exchanger 10 and opposite to the light-transmitting window. This allows the photoresistor 130 to detect the flame while being unaffected by the internal temperature of the heat exchanger 10.

[0056] As shown in the figure, this embodiment provides a flame monitoring device 100, which is arranged on a heat exchanger 10 of a gas water heater. The flame monitoring device 100 includes a photoresistor 130, which is arranged close to a heat dissipation coil of the gas water heater.

[0057] In this embodiment, the flame monitoring device 100 is specifically disposed at a lower portion of the heat exchanger 10 close to the combustion chamber and facing the light-transmitting window of the heat exchanger 10 .

[0058] like Figure 3 、 5 As shown, the photoresistor 130 is separated from the interior of the heat exchanger 10 by the heat insulation sheet 110, and the heat insulation sheet 110 is light-transmissive.

[0059] In this embodiment, the heat insulation sheet 110 is tightly attached to the surface of the heat exchanger 10 through the pressing plate 120 and rivets, covering the position of the light-transmitting window.

[0060] The heat insulating sheet 110 can transmit light and isolate the heat inside the heat exchanger 10 at the same time, thereby preventing the photoresistor 130 from being aging due to heat.

[0061] like Figure 5 As shown, there is a gap between the photoresistor 130 and the thermal insulation sheet 110 .

[0062] An air layer 170 is formed between the photoresistor 130 and the heat insulating sheet 110 , further isolating the photoresistor 130 from heat exchange within the heat exchanger 10 to prevent the photoresistor 130 from failing due to heat.

[0063] The operating temperature of the photoresistor 130 cannot exceed 85°C. This device fully considers the operating temperature of the photoresistor 130. It uses an air layer 170 for thermal insulation and a heat sink water cooling system to cool the photoresistor 130 area. This ensures that the flame monitoring device 100 can operate at an appropriate temperature for a long period of time.

[0064] The heat-insulating sheet 110 of this embodiment is a mica sheet. The mica sheet has the characteristics of high temperature resistance and strong light transmittance. In other embodiments, of course, a heat-resistant transparent glass sheet or other light-transmitting heat-insulating material can also be used.

[0065] In this embodiment, the mica sheet is pressed onto the surface of the heat exchanger 10 by a pressing plate 120 , and the pressing plate 120 is fixed by rivets.

[0066] like Figure 3-5 As shown, the flame monitoring device 100 also includes a light shield 150, which includes a first open surface 151 and a second open surface 152. The first open surface 151 is arranged to fit the surface of the heat exchanger 10, and the second open surface 152 of the light shield 150 fits the upper surface of the heat dissipation coil. The light shield 150 and the surface of the heat exchanger 10 and the upper surface of the heat dissipation coil are arranged to form a closed cavity, and the photoresistor 130 is arranged in the closed cavity.

[0067] The light shield 150 is box-shaped and has two open surfaces, while the other surfaces are closed. The first open surface 151 and the second open surface 152 are respectively connected to the heat exchanger 10 and the heat dissipation coil and are closed to achieve a completely closed effect.

[0068] The light shield 150 contacts the heat exchanger 10 and the heat dissipation coil and seals the photoresistor 130 therein, thereby preventing light leakage from causing misjudgment of the photoresistor 130 .

[0069] In this embodiment, the photoresistor 130 is fixed to the resistor mounting plate 160 in the light shield 150 by screws.

[0070] like Figure 4 、 5 As shown, the second open surface 152 includes an arc-shaped groove 153 whose shape matches the upper surface of the heat dissipation coil, and the heat dissipation coil is embedded in the arc-shaped groove 153.

[0071] The light shield 150 and the heat dissipation coil are nested and connected, which has a better sealing effect and is less likely to leak light. At the same time, the heat dissipation coil can be embedded in the light shield 150, making it closer to the photoresistor 130, and having a better heat dissipation effect.

[0072] like Figure 3-5 As shown, the flame monitoring device 100 further includes a flat sealing gasket 141 and a coil sealing gasket 142 . The flat sealing gasket 141 is arranged on the first open surface 151 , and the coil sealing gasket 142 is arranged on the second open surface 152 .

[0073] A flat sealing gasket 141 and a coil sealing gasket 142 are provided at the connection to fill the gap at the connection and prevent light leakage from causing misjudgment of the photoresistor 130 .

[0074] like Figure 6As shown, a heat dissipation hole 1421 is opened in the middle of the coil sealing gasket 142.

[0075] The coil sealing gasket 142 is attached to the heat dissipation coil, and the heat dissipation holes 1421 are opened on the coil sealing gasket 142 without affecting the heat dissipation effect of the heat dissipation coil on the inside of the light shield 150.

[0076] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

Claims

1. A flame monitoring device for a gas water heater, characterized in that: The flame monitoring device is arranged on the heat exchanger of the gas water heater, and the flame monitoring device includes a photoresistor, and the photoresistor is arranged close to the heat dissipation coil of the gas water heater; The photoresistor is separated from the interior of the heat exchanger by a heat insulation sheet, and the heat insulation sheet is light-transmissive; There is a gap between the photoresistor and the thermal insulation sheet; The thermal insulation sheet is a mica sheet; The flame monitoring device also includes a light shield, which includes a first open surface and a second open surface. The first open surface is arranged to fit the surface of the heat exchanger, and the second open surface of the light shield is arranged to fit the upper surface of the heat dissipation coil. The light shield, the surface of the heat exchanger, and the upper surface of the heat dissipation coil are arranged to form a closed cavity, and the photoresistor is arranged in the closed cavity.

2. The flame monitoring device according to claim 1, characterized in that: The second open surface includes an arc-shaped groove whose shape matches the upper surface of the heat dissipation coil, and the heat dissipation coil is embedded in the arc-shaped groove.

3. The flame monitoring device according to claim 1, characterized in that: The flame monitoring device further includes a flat sealing gasket and a coil sealing gasket. The flat sealing gasket is arranged on the first open surface, and the coil sealing gasket is arranged on the second open surface.

4. The flame monitoring device according to claim 3, characterized in that: A heat dissipation through hole is provided in the middle of the coil sealing gasket.

5. A gas water heater, characterized in that: The invention comprises a heat exchanger, a heat dissipation coil arranged on the surface of the heat exchanger and a flame monitoring device according to any one of claims 1 to 4.

6. The gas water heater according to claim 5, characterized in that A light-transmitting window is provided on the surface of the heat exchanger, and the flame monitoring device is arranged outside the heat exchanger at a position facing the light-transmitting window.

Images