Small space self-powered temperature difference power generation system and method without external cold source

Abstract

A small-space self-powered temperature difference power generation system and method without an external cold source, belonging to the technical field of gas stoves. The system comprises a panel (11), a chassis (12), a temperature difference power generation device (2), an energy storage module (3) and an electronic pulse igniter (4) of a stove (1). The stove (1) comprises a panel (11), a stove body and its chassis (12), an adjustable damper, and an ignition switch; the temperature difference power generation device (2) comprises a heat conducting block (21), a temperature difference power generation element (22), a radiator (23), and a liquid storage tank (25); the energy storage module (3) comprises a boost module (31), a super capacitor (321), and a voltage stabilizing module (33); the present invention improves the thermal energy utilization rate of the stove and realizes self-powered operation, eliminating the use of dry batteries, wherein the passive cooling system without external power assistance ensures the long-term stable operation of the temperature difference power generation device, thereby improving the service life of the stove.

Description

Technical Field

[0001] The present invention relates to a small space self-powered temperature difference power generation system and method without an external cold source, and in particular to a temperature difference power generation structure inside a gas cooker and a matching charging and discharging energy storage circuit design, belonging to the technical field of gas cookers and the field of electronics and electrical engineering. Background Art

[0002] There are two ignition methods for gas stoves: electronic pulse ignition and piezoelectric ceramic ignition. The former has a higher ignition hit rate, generally reaching 100%. Embedded stoves use electronic pulse ignition and are equipped with flameout protection devices in accordance with national regulations (GB16410-2007), so that the stove can cut off the gas source in time when the flameout is accidentally turned off to avoid danger caused by gas leakage. The flameout protection and pulse electric spark power components of the embedded stove are integrated in the electronic pulse igniter, which requires dry batteries to drive. Therefore, the stove needs to replace the battery after a period of use. The unreasonable recycling of waste batteries will pose a risk of environmental pollution. In addition, some embedded stoves are difficult to disassemble and assemble, and it is difficult for users to replace the battery independently. Therefore, this paper proposes that the temperature difference power generation technology can be used to convert part of the waste heat during the combustion of the stove into electrical energy to replace the dry battery to power the electronic pulse igniter, so as to achieve the purpose of energy saving and environmental protection.

[0003] Compared with traditional power generation methods, thermoelectric power generation has the advantages of reliable performance, no noise pollution, no moving parts, less maintenance, and can work for a long time in extremely harsh environments. However, there are also defects that cannot be ignored. The biggest difficulty in using thermoelectric power in the power generation process is that the temperature difference is too small and the energy density is too low. Therefore, the key to converting thermoelectric power into electrical energy is to enhance heat transfer technology. Although some people have proposed to use thermoelectric power generation in gas stoves, there is no good design of passive heat dissipation at the cold end, and no one has proposed to apply the thermosyphon principle to the heat dissipation of the thermoelectric power generation cold end of gas stoves.

[0004] In order to allow the electronic pulse igniter to work when the stove is turned off, that is, when the thermoelectric element does not output electrical energy, an energy storage module must be used to store the electrical energy generated by the heat input of the thermoelectric device. However, there are few well-designed and low-cost charging and discharging energy storage circuits that can be used with the thermoelectric power generation and internal electrical components of gas stoves.

[0005] In summary, the present invention proposes a small-space self-powered temperature difference power generation system and method without an external cold source. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art, and the present invention provides the following technical solutions:

[0007] The present invention provides a small-space self-powered temperature difference power generation system without an external cold source, which comprises a cooker, a temperature difference power generation device, an energy storage module and an electronic pulse igniter in sequence; the cooker comprises a panel, a chassis, a burner, an ignition switch, etc.; the temperature difference power generation device comprises a heat conductive block, a temperature difference power generation element, a radiator, and a liquid storage tank; the energy storage module consists of a boost module, a super capacitor, and a voltage stabilizing module.

[0008] Furthermore, the heat conductive block is in close contact with the high-temperature surface of the chassis of a stove, the hot end of the temperature difference power generation element is in close contact with the heat conductive block, and the cold end of the temperature difference power generation element is in close contact with the radiator; the rear surface of the radiator is provided with ribs, and the function of the ribs is to increase the heat dissipation area and enhance the convection heat transfer on the surface of the radiator; the rear surface of the radiator is tightly sealed with the front surface of the liquid storage tank to ensure that the cooling medium will not leak when the stove is in long-term operation, and the ribs extend into the interior of the liquid storage tank through the opening on the front surface, directly contacting the cooling medium therein, and temporarily storing heat in the medium. A partition is arranged in the liquid storage tank, which is composed of a horizontal bottom plate and at least two vertical side plates. The height of the horizontal bottom plate is level with the bottom of the radiator fins. A cold channel is formed between the horizontal bottom plate and the bottom surface of the liquid storage tank to guide the flow of colder working fluid so that the working fluid can flow into the fin area of ​​the radiator; the vertical side plates cover the fin area of ​​the radiator but do not contact the fins, because when the partition contacts the fins, the contact area between the radiator and the working fluid will be reduced, affecting the heat exchange effect; the area covered by the vertical side plates forms a hot channel to guide the working fluid flowing through the fins into the upper area of ​​the liquid storage tank.

[0009] Furthermore, the energy storage module is composed of a boost module, a supercapacitor, and a voltage stabilizing module; the voltage input end of the boost module is connected to the temperature difference power generation element with a wire, and the voltage output end is connected to the positive and negative electrodes of the supercapacitor with a wire, and the positive and negative electrodes are then connected to the voltage input end of the voltage stabilizing module, and the voltage output end of the voltage stabilizing module is connected to the electronic pulse igniter with a wire.

[0010] Furthermore, the fin structure of the above-mentioned radiator is rectangular fins, or needle-shaped fins, or oblique fins. The purpose of adding fins is to increase the heat exchange area between the radiator and the liquid working medium, thereby enhancing natural convection heat exchange.

[0011] Furthermore, the area covered by the fins of the above-mentioned radiator accounts for more than 80% of the rear surface of the radiator, and the ratio of rib height to rib thickness is greater than 5. Such a ratio helps to form a more reasonable rib spacing, so that the fluid in the hot channel is not easy to form a flow dead zone in the fin area.

[0012] Furthermore, the partition is made of heat-insulating material, and the thermal conductivity of the material is in the range of 0 to 0.3 W / m•K. The thermoelectric element is a semiconductor thermoelectric sheet or a semiconductor refrigeration sheet, or a semiconductor power generation stack, or a semiconductor refrigeration stack, or an integrated product of a PN junction and a printed circuit.

[0013] Furthermore, the working fluid in the liquid storage tank is water or paraffin. The working fluid filling volume of the liquid storage tank is 70-100% of the entire internal volume of the liquid storage tank, or the height of the filling level of the working fluid must exceed the fin area of ​​the radiator. When the interior is not full of liquid, a certain vacuum is drawn to form a micro-negative pressure environment, which can reduce the boiling point of the working fluid, generate bubbles to destroy the hot edge surface layer at the fin wall, increase the average convection heat transfer coefficient on the wet surface of the fin, further reduce the total thermal resistance of the radiator, and enhance natural convection heat dissipation.

[0014] Furthermore, the supercapacitor is an energy storage element, or a rechargeable nickel-metal hydride battery or lithium battery. The energy storage element is used to store the electric energy generated by the intermittent operation of the thermoelectric power generation element. When the energy storage element is a nickel-metal hydride battery or a lithium battery, the boost module is replaced by a charging module of the nickel-metal hydride battery or the lithium battery.

[0015] Furthermore, the method of the small space self-powered temperature difference power generation system without an external cold source is characterized by comprising the following process: the hot end heat conducting block of the temperature difference power generation device is closely attached to the high temperature surface of the bottom plate of a stove, absorbing part of the waste heat of gas combustion, the temperature difference power generation element uses a small part of the heat to perform temperature difference power generation, and the remaining heat is transferred to the working fluid in the liquid storage tank of the passive heat dissipation system through the radiator at the cold end. The fin type radiator dissipates heat into the working fluid, and a temperature difference is formed in the working fluid near the fin area to establish a density gradient, so that the hotter liquid generates buoyancy and transfers to the upper part of the liquid storage tank. Since the liquid leaves the fin area of ​​the radiator, the fresh and colder liquid will be supplemented to the fin area through the channel separated by the partition, and then flow through the microchannel fin area of ​​the radiator. At the same time, the liquid passing through the fin area is replaced by the fresh colder liquid, the heat is taken away by the hot fluid, and the colder liquid is provided by the area outside the channel at the bottom of the water tank, and finally a thermal siphon flow cycle is established to become a quasi-heat pipe passive heat dissipation system.

[0016] Furthermore, the output end of the thermoelectric power generation element is connected to a DC boost module, which can output a low-voltage input voltage at a higher stable voltage. A DC voltage regulator module is connected to the input end of the electronic pulse igniter, which can output a stable rated voltage to the electronic pulse igniter. The boost module, supercapacitor and voltage regulator module form an energy storage module to store the electric energy generated by the thermoelectric power generation device when the stove is ignited. The stored electric energy can be supplied to the electronic pulse igniter all the time, so that it is always in a standby state. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of this patent;

[0018] Figure 2 It is a schematic diagram of the liquid storage tank and the partition structure;

[0019] Figure 3 is a schematic diagram of the radiator structure;

[0020] Figure 4 It is a schematic diagram of a circuit using a supercapacitor as an energy storage element;

[0021] Figure 5 This is a schematic diagram of a circuit using a nickel-hydrogen battery as an energy storage element;

[0022] Figure 6 This is a schematic diagram of a circuit using a lithium battery as an energy storage element.

[0023] Reference numerals in the figure: 1-stove, 11-panel, 12-chassis, 2-temperature difference power generation device, 21-heat conductive block, 22-temperature difference power generation element, 23-radiator, 24-partition, 25-liquid storage tank, 3-energy storage module, 31-boost module, 321-supercapacitor, 322-nickel-metal hydride battery, 323-lithium battery, 33-voltage stabilizing module, 4-electronic pulse igniter. Specific implementation methods

[0024] The present patent is further described below in conjunction with the accompanying drawings.

[0025] like Figure 1 and 2As shown, a small space self-powered temperature difference power generation system and method without an external cold source performs temperature difference power generation in the following manner: the temperature difference power generation device can convert part of the waste heat from the combustion of the stove into direct current, which is directly supplied to the electronic pulse igniter. The heat conductive block and the finned heat sink clamp a temperature difference power generation element, the heat conductive block is close to the hot end of the power generation element, and the heat sink serves as the cold end. The heat from the stove is first transferred to the temperature difference power generation element through the heat conductive block. The power generation element uses a very small part of the heat to perform temperature difference power generation, and the remaining heat is transferred to the working fluid in the liquid storage tank through the radiator at the cold end. The finned heat sink dissipates the heat at the cold end into the liquid storage tank, and a temperature difference is formed in the liquid in the hot channel to establish a density gradient, so that the hotter liquid generates buoyancy and transfers to the upper part of the liquid storage tank. Since the liquid leaves the lower area of ​​the hot channel, fresh water will be replenished to the lower area through the cold channel, and then flow through the microchannel fin area of ​​the radiator. At the same time, the liquid leaving the fin area through the hot channel is replaced by the freshly entering colder liquid, and the heat is taken away by the hot fluid. The colder liquid is provided by the area outside the hot channel of the liquid storage tank, and finally a thermosiphon flow cycle is established, which becomes a quasi-heat pipe passive heat dissipation system. The liquid working medium in the liquid storage tank has a large specific heat capacity, so it must absorb a large amount of heat within a period of time to significantly increase the water supply temperature in the cold channel. During this stage, the heat at the cold end can be quickly transferred to the working fluid in the water tank. The liquid storage tank can be regarded as a heat storage device, during which the two ends of the thermoelectric power generation element can maintain a high temperature difference. However, as the stove continues to work, the working medium temperature will inevitably continue to rise. At this time, the system will dissipate part or all of the heat provided by the cold end through natural convection between the stove and the outside air. At this time, the liquid storage tank can be regarded as a single-phase thermosiphon heat pipe to conduct the heat from the cold end of the power generation plate. The liquid storage tank acts as a gravity pump, heat storage device and heat transfer medium, providing short-term and efficient heat dissipation for the thermoelectric power generation element at regular intervals.

[0026] like Figure 3 As shown, a rectangular fin is arranged on the side of the radiator in contact with the liquid in the liquid storage tank, the area covered by the fin accounts for more than 80% of the surface where the fin is located, and the ratio of the rib height to the rib thickness is more than 5.

[0027] like Figure 4 As shown, a small space self-powered temperature difference power generation system and method without an external cold source stores electrical energy in the following manner (using a supercapacitor as an energy storage element): the electrical energy generated by the temperature difference power generation element is first stored in the supercapacitor, and then continuously powers the electronic pulse igniter to keep it in a standby state.

[0028] like Figure 5As shown, a small space self-powered temperature difference power generation system and method without an external cold source stores electric energy in the following manner (using nickel-hydrogen batteries as energy storage elements): the electric energy generated by the temperature difference power generation element is first stored in the nickel-hydrogen battery, and then continuously powers the electronic pulse igniter to keep it in standby mode.

[0029] like Figure 6 As shown, a small space self-powered temperature difference power generation system and method without an external cold source stores electrical energy in the following manner (using a lithium battery as an energy storage element): the electrical energy generated by the temperature difference power generation element is first stored in the lithium battery, and then continuously powers the electronic pulse igniter to keep it in a standby state.

Claims

1. A small space self-powered temperature difference power generation system without an external cold source, characterized by: It comprises, in sequence, a stove (1), a temperature difference power generation device (2), an energy storage module (3) and an electronic pulse igniter (4); The stove (1) comprises a panel (11), a stove body and a chassis (12), an air damper, and an ignition switch; The above-mentioned temperature difference power generation device (2) comprises a heat conducting block (21), a temperature difference power generation element (22), a radiator (23), and a liquid storage tank (25); the above-mentioned heat conducting block (21) is closely attached to the high-temperature surface of a bottom plate (12) of a stove, the hot end of the temperature difference power generation element (22) is closely attached to the heat conducting block (21), and the cold end of the temperature difference power generation element (22) is closely in contact with the radiator (23); the rear surface of the radiator (23) is closely attached to the front surface of the liquid storage tank (25) and sealed, and the fins extend into the interior of the liquid storage tank (25) through the opening of the front surface and directly contact the working medium therein; A partition (24) is arranged inside the liquid storage tank (25); the partition (24) is composed of a horizontal bottom plate and at least two vertical side plates, the height of the horizontal bottom plate is level with the bottom of the fins of the radiator (23), a cold channel is formed between the horizontal bottom plate and the bottom surface of the liquid storage tank (25), the vertical side plates cover the fin area of ​​the radiator (23) but do not contact the fins, and the area covered by the vertical side plates forms a hot channel; the radiator (23), the partition (24) and the liquid storage tank (25) constitute a passive heat dissipation system; The energy storage module (3) is composed of a boost module (31), a super capacitor (321), and a voltage stabilizing module (33); the voltage input end of the boost module (31) is connected to the temperature difference power generation element (22) by a wire, the voltage output end is connected to the positive and negative electrodes of the super capacitor (321) by a wire, and the positive and negative electrodes are connected to the voltage input end of the voltage stabilizing module (33), and the voltage output end of the voltage stabilizing module (33) is connected to the electronic pulse igniter (4) by a wire; The fin structure of the heat sink (23) is a rectangular fin, or a needle-shaped fin, or an oblique fin; The area covered by the fins of the heat sink (23) accounts for more than 80% of the rear surface of the heat sink (23), and the ratio of the rib height to the rib thickness is more than 5.

2. The small space self-powered temperature difference power generation system without external cold source according to claim 1 is characterized by: The partition (24) is made of heat-insulating material, and the thermal conductivity of the material is in the range of 0 to 0.3 W / m·K.

3. The small space self-powered temperature difference power generation system without external cold source according to claim 1 is characterized by: The above-mentioned temperature difference power generation element (22) is a semiconductor temperature difference power generation sheet or a semiconductor cooling sheet, or a semiconductor power generation stack, or a semiconductor cooling stack, or an integrated product of a PN junction and a printed circuit.

4. The small space self-powered temperature difference power generation system without external cold source according to claim 1 is characterized by: The working fluid in the liquid storage tank (25) is water or paraffin; after the working fluid is injected into the liquid storage tank (25), a vacuum is drawn to form a negative pressure environment, and the filling amount of the working fluid accounts for 70% to 100% of the internal volume of the entire liquid storage tank (25), or the height of the filling level of the working fluid exceeds the fin area of ​​the radiator (23).

5. The method of the small space self-powered temperature difference power generation system without an external cold source according to any one of claims 1 to 4, characterized in that The process includes: The hot end heat conducting block (21) of the above-mentioned temperature difference power generation device (2) is closely attached to the high temperature surface of the bottom plate (12) of a stove, absorbing part of the waste heat from the combustion of gas. The temperature difference power generation element (22) uses a small part of the heat to perform temperature difference power generation, and the remaining heat is transferred to the working fluid in the liquid storage tank (25) through the radiator (23) at the cold end; the radiator (23) quickly dissipates the heat into the working fluid, and a temperature difference is formed in the working fluid near the fin area, thereby establishing a density gradient, so that the hotter liquid generates buoyancy and is transferred to the upper part of the liquid storage tank (25) through the heat channel. Since the liquid leaves the fin area of ​​the radiator (23), the fresh and colder liquid will be replenished to the fin area through the heat channel separated by the partition (24), and then flow through the fin area of ​​the radiator (23); at the same time, the liquid passing through the fin area is replaced by the fresh colder liquid, and the heat is taken away by the hot fluid, and finally a natural convection cycle is established; The output end of the above-mentioned temperature difference power generation element (22) is connected to a DC boost module (31), which can output a low voltage input voltage at a higher stable voltage; the input end of the electronic pulse igniter (4) is connected to a DC voltage stabilizing module (33), which can output a stable rated voltage to the electronic pulse igniter (4); the boost module (31), the super capacitor (321) and the voltage stabilizing module (33) form an energy storage module (3) for storing the electric energy generated by the temperature difference power generation device (2) when the stove (1) is ignited; the stored electric energy can be continuously supplied to the electronic pulse igniter (4), so that the electronic pulse igniter (4) is always in a standby state.

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