Efficient Combustion System for Combustible Ice

Abstract

The present invention discloses a high-efficiency combustion system for combustible ice, comprising: a combustible ice storage unit and a combustion unit. A burner is provided at the front end of the furnace of the combustion unit, and a flue gas main pipe is connected to the rear end of the furnace of the combustion unit. The burner is provided with a first gas inlet, a second gas inlet, an auxiliary gas inlet and a combustion gas outlet. A combustion nozzle is provided at the first gas inlet. The combustion nozzle is provided with a first air inlet, a second air inlet and a mixed gas outlet. The first air inlet is communicated with the combustible ice storage unit through a high-pressure natural gas pipeline. The second air inlet is communicated with an air source. The mixed gas outlet is communicated with the first gas inlet of the burner. A natural gas branch line is connected to the high-pressure natural gas pipeline. A gas turbine is provided on the natural gas branch line. The natural gas branch line transports 50% - 60% of the high-pressure natural gas in the high-pressure natural gas pipeline to the gas turbine, and the low-pressure natural gas after pressure reduction is transported to the second gas inlet of the burner.

Description

Technical Field

[0001] The present invention relates to the technical field of combustible ice, and in particular to a combustible ice combustion system. Background Art

[0002] Combustible ice looks like ice and is combustible, also known as "solid gas" or "steam ice". Combustible ice is a crystal formed by methane and water under high pressure and low temperature conditions. Combustible ice is widely distributed and stored in sediments in the sea or frozen soil in the land. It has high resource density, large reserves, and wide distribution. It has extremely high mining value and is an important low-carbon clean energy source to replace in the future.

[0003] At present, people are vigorously using methane hydrate to generate electricity, which effectively avoids the defects of hydropower generation being restricted by geographical location and environment, the air pollution caused by thermal power generation, the immature nuclear power generation technology, and the large input and low output of wind power generation.

[0004] However, current research has only stopped at combustible ice generators, and has not systematically and fully utilized the production capacity after the hydrolysis of combustible ice, and energy waste still exists.

[0005] For example, a combustible ice power generation device disclosed in Chinese patent application No. 201811341947.3 includes a high-temperature combustion chamber, a steam turbine, a reducer and an asynchronous AC generator, wherein the reducer is built into the steam turbine and arranged on one side of the output end of the steam turbine, the asynchronous AC generator is connected to the output end of the steam turbine, and a jet nozzle is arranged on one side of the high-temperature combustion chamber. The steam generated in the high-temperature combustion chamber is directly injected to the input end of the steam turbine through the jet nozzle to drive its operation to generate power. After the reducer adjusts the speed of the steam turbine, it drives the asynchronous AC generator to operate and generate electricity. However, the combustible ice power generation device has the following disadvantages or shortcomings: the process of decomposing combustible ice requires great energy consumption.

[0006] Another example is a combustible ice power generation device disclosed in Chinese patent application No. 201210323240.6. The power generation device specifically includes a combustible ice generator and a power station, wherein the structure of the power station includes an engine, which uses compressed natural gas (CNG) produced after the decomposition of combustible ice as fuel, so that the mined combustible ice can be directly put into power generation production, thereby increasing the utilization rate, eliminating the need for transportation, and saving a large amount of transportation costs. In addition, the CNG produced by combustible ice is pollution-free after combustion, achieving an environmentally friendly effect. However, the combustible ice power generation device has the following disadvantages or shortcomings: (1) the process of decomposing combustible ice requires a great deal of energy consumption; (2) the heat energy generated after the combustion of combustible ice is not fully utilized, resulting in energy waste.

[0007] Therefore, it has become an urgent problem in the industry to provide a high-efficiency combustion system for combustible ice that can reduce energy consumption and pollution and fully develop the energy efficiency of combustible ice at the same time. Summary of the Invention

[0008] The object of the present invention is to provide a high-efficiency combustion system for combustible ice, which can fully and efficiently utilize the gas generated by the hydrolysis of combustible ice for power generation and the heat energy of the high-temperature flue gas generated after its combustion, and significantly improve the energy utilization rate.

[0009] To achieve the above object, the present invention provides a high-efficiency combustion system for combustible ice, including: a combustible ice storage unit and a combustion unit. A burner is provided at the front end of the furnace of the combustion unit, and a flue gas main pipe for discharging high-temperature flue gas is connected to the rear end of the furnace of the combustion unit. Among them, the burner is provided with a first gas inlet, a second gas inlet, an auxiliary gas inlet and a combustion gas outlet. A combustion nozzle is provided at the first gas inlet. The combustion nozzle is provided with a first air inlet, a second air inlet, a third air inlet and a mixed gas outlet. Among them, the first air inlet is connected to the combustible ice storage unit through a high-pressure natural gas pipeline, the second air inlet is connected to an air source, and the mixed gas outlet is connected to the first gas inlet of the burner; a natural gas branch line is connected to the high-pressure natural gas pipeline, and a gas turbine is provided on the natural gas branch line. The natural gas branch line transports 50% - 60% of the high-pressure natural gas in the high-pressure natural gas pipeline to the gas turbine for power generation, and the generated electric energy is stored in an electric energy storage device. The high-pressure natural gas becomes low-pressure natural gas after passing through the gas turbine and is transported to the second gas inlet of the burner through a low-pressure natural gas pipeline.

[0010] Optionally, a flue gas branch line is connected to the flue gas main pipe, and the flue gas branch line is connected to the third air inlet of the combustion nozzle to draw 10% - 30% of the high-temperature flue gas in the flue gas main pipe into the combustion nozzle to be mixed with air and high-pressure natural gas and then sent to the furnace of the combustion unit for combustion.

[0011] Optionally, the burner includes a coaxial inner cylinder and an outer cylinder. The front ends of the inner cylinder and the outer cylinder are sealed, and the rear ends of the inner cylinder and the outer cylinder are the combustion gas outlets, which are connected to the furnace of the combustion unit. The first gas inlet is opened on the upper side wall at the front end of the outer cylinder, the auxiliary gas inlet is opened on the lower side wall at the front end of the inner cylinder, and the second gas inlet is opened at the front end of the inner cylinder.

[0012] Among them, the first gas inlet is opened on the upper side wall at the front end of the outer cylinder, so that the high-pressure natural gas, high-temperature flue gas and air enter the burner tangentially, so that they form a swirl in the outer cylinder of the burner, enhancing the mixing between the three gases. At the same time, the arrangement that the auxiliary gas inlet is opened on the lower side wall at the front end of the inner cylinder makes the low-pressure natural gas entering from the front end of the inner cylinder mix more evenly with the auxiliary gas entering the inner cylinder tangentially.

[0013] Optionally, the combustible ice storage unit includes a plurality of heating devices, combustible ice containers disposed in each heating device, a common pipe connected to the gas outlet of the combustible ice container, and a gas storage tank connected to the outlet of the common pipe.

[0014] Optionally, the heating device is a water jacket with a hot water inlet and a cold water outlet, and the hot water inlets and cold water outlets between two adjacent water jackets are connected through pipes.

[0015] Optionally, the high-efficiency combustible ice system further includes a first heat exchanger, which includes a high-temperature flue gas inlet, a medium-temperature flue gas outlet, a cold air inlet, and a hot air outlet. The high-temperature flue gas inlet is connected to the main flue gas pipe, and the hot air outlet is connected to the combustion-supporting gas inlet of the burner through a hot air pipeline.

[0016] Among them, the high-temperature flue gas at 800 - 1300 degrees Celsius from the furnace of the combustion unit is discharged into the main flue gas pipe. 10 - 30% of the high-temperature flue gas, which accounts for the total amount of high-temperature flue gas, is induced back into the burner, mixed with high-pressure natural gas and air, and then burned, thereby effectively increasing the furnace temperature and maintaining the stability of the combustion temperature; 70% - 90% of the high-temperature flue gas enters the first heat exchanger, exchanges heat with the cold air at 20 - 25 degrees Celsius, and the hot air at 500 - 800 degrees Celsius formed enters the burner, mixes with low-pressure natural gas, and then enters the combustion unit for combustion, further improving the combustion efficiency of low-pressure natural gas.

[0017] Optionally, it further includes a second heat exchanger, which includes a medium-temperature flue gas inlet, a low-temperature flue gas outlet, a cold water inlet, and a hot water outlet. The medium-temperature flue gas inlet is connected to the medium-temperature flue gas outlet of the first heat exchanger, the low-temperature flue gas outlet is connected to the chimney through a low-temperature flue gas pipeline, the cold water inlet is connected to the cold water outlet of the water jacket at the end of the combustible ice storage unit, and the hot water outlet is connected to the hot water inlet of the water jacket at the beginning of the combustible ice storage unit.

[0018] Among them, the medium-temperature flue gas at 300 - 400 degrees Celsius from the first heat exchanger enters the second heat exchanger, exchanges heat with the cold water discharged from the water jacket at the end of the combustible ice storage unit at 30 - 40 degrees Celsius, and the hot water at 80 - 90 degrees Celsius formed then enters the hot water inlet of the water jacket at the beginning of the combustible ice storage unit, thereby completing the heating of all the combustible ice containers. The cold flue gas at 180 - 200 degrees Celsius formed after heat exchange is discharged to the chimney.

[0019] Optionally, a pressure reducing valve is provided on the combustible ice connection pipeline between the gas outlet of each combustible ice container and the common pipe, and an electric control valve is provided on the common pipe connection pipeline between the outlet of the common pipe and the gas storage tank.

[0020] Preferably, a gas flow meter is also provided on each combustible ice connecting pipeline to real-time monitor the flow rate of the high-pressure natural gas discharged from the combustible ice container. When it is monitored that there is no high-pressure natural gas discharged from a combustible ice container, a new combustible ice container can be immediately replaced.

[0021] Optionally, a first fan is provided on the hot air pipeline to introduce hot air into the combustion-supporting gas inlet, and a second fan is provided on the low-temperature flue gas pipeline to introduce low-temperature flue gas into the chimney.

[0022] Optionally, the first fan, the second fan, the pressure reducing valve, and the electric control valve are respectively electrically connected to the electric energy storage device to obtain electric energy.

[0023] The beneficial effects of the present invention are as follows: (1) The number of combustible ice containers can be adjusted according to needs, thereby controlling the generated amount of electric energy and avoiding unnecessary waste; (2) The combustion system is pollution-free, and the hot air generated by heat exchange of the high-temperature flue gas with cold air can be used for combustion, which not only effectively utilizes the heat of the high-temperature flue gas and the hot air, but also improves the combustion efficiency; (3) Part of the high-temperature flue gas is ejected to the nozzle to be mixed with air for combustion support, which not only effectively recycles the hot flue gas, but also reduces the flue gas emission amount and the generation amount of nitrogen oxides, realizing energy conservation and environmental protection; (4) The heat of the medium-temperature flue gas is used for heat exchange with cold water, and the generated hot water is used to heat the combustible ice, realizing the cyclic use of energy, energy conservation and high efficiency. Brief Description of the Drawings

[0024] Figure 1 Shows a schematic structural diagram of the high-efficiency combustible ice combustion system of the present invention.

[0025] Figure 2 Shows a schematic structural diagram of the burner of the present invention.

[0026] Figure 3 Shows Figure 2 the schematic A-A cross-sectional view of

[0027] Figure 4 Shows Figure 2 the schematic B-B cross-sectional view of Detailed Description of the Embodiment

[0028] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0029] Please refer to Figure 1, as a non - restrictive embodiment, the high - efficiency combustible ice combustion system of the present invention includes: a combustible ice storage unit 10, a combustion unit 20, a first heat exchanger 30, and a second heat exchanger 40.

[0030] At the front end of the furnace 21 of the combustion unit 20, there is a burner 22, and at the rear end of the furnace 21 of the combustion unit 20, there is a flue gas main pipe L1 connected for discharging high - temperature flue gas.

[0031] As Figure 1 shown, the burner 22 is provided with a first gas inlet 221, a second gas inlet 222, an auxiliary gas inlet 223, and a combustion gas outlet 224. At the first gas inlet 221, there is a combustion nozzle 220. The combustion nozzle 220 is provided with a first air inlet 2201, a second air inlet 2202, a third air inlet 2203, and a mixed gas outlet 2204. Among them, the first air inlet 2201 is connected to the combustible ice storage unit 10 through a high - pressure natural gas pipeline L2, the second air inlet 2202 is connected to an air source, and the mixed gas outlet 2204 is connected to the first gas inlet 221 of the burner 22. Among them, the combustion nozzle 220 adopts an ejector structure, which uses the pressure of the high - pressure natural gas entering the first air inlet 2201 to form a suction force, sucking air into the combustion nozzle 220 through the second air inlet 2202. This process does not require other power, so it is more energy - saving.

[0032] A natural gas branch line L3 is connected to the high - pressure natural gas pipeline L2. A gas turbine 50 is provided on the natural gas branch line L3. The natural gas branch line L3 transports 50% - 60% of the high - pressure natural gas in the high - pressure natural gas pipeline L2 to the gas turbine 50 for power generation, and the generated electric energy is stored in an electric energy storage device 60. The high - pressure natural gas becomes low - pressure natural gas after passing through the gas turbine 50 and is transported to the second gas inlet 222 of the burner 22 through a low - pressure natural gas pipeline L4.

[0033] In this non - restrictive embodiment, a flue gas branch line L5 is connected to the flue gas main pipe L1, and the flue gas branch line L5 is connected to the third air inlet 2203 of the combustion nozzle 220. Similarly, because the combustion nozzle 220 adopts an ejector structure, it uses the pressure of the high - pressure natural gas entering the first air inlet 2201 to form a suction force, so that 10% - 30% of the high - temperature flue gas in the flue gas main pipe L1 can be ejected into the combustion nozzle 220, mixed with air and high - pressure natural gas, and then sent into the furnace 21 of the combustion unit 20 for combustion.

[0034] As another non - restrictive embodiment, as Figure 2As shown, the burner 22 includes a coaxial inner cylinder 225 and an outer cylinder 226. The front ends of the inner cylinder 225 and the outer cylinder 226 are sealed, and the rear ends of the inner cylinder 225 and the outer cylinder 226 are combustion gas outlets 224, which are connected to the furnace 21 of the combustion unit 20. The first gas inlet 221 is opened at the upper side wall of the front end of the outer cylinder 226, the combustion-supporting gas inlet 223 is opened at the lower side wall of the front end of the inner cylinder 225, and the second gas inlet 222 is opened at the front end of the inner cylinder 225.

[0035] Thus, as Figure 3 shown, the setting that the combustion-supporting gas inlet 223 is opened at the lower side wall of the front end of the inner cylinder 225 enables the low-pressure natural gas entering from the front end of the inner cylinder 225 to be more evenly mixed with the combustion-supporting gas tangentially entering the inner cylinder, and the combustion temperature can reach about 800 degrees Celsius. At the same time, as Figure 4 shown, the first gas inlet 221 is opened at the upper side wall of the front end of the outer cylinder 226, enabling the high-pressure natural gas, high-temperature flue gas, and air to tangentially enter the burner 22, forming a swirl in the outer cylinder 226 of the burner 22, enhancing the mixing between the three gases, and making the combustion temperature reach about 1300 degrees Celsius.

[0036] As another non-limiting embodiment, as Figure 1 shown, the first heat exchanger 30 includes a high-temperature flue gas inlet 301, a medium-temperature flue gas outlet 302, a cold air inlet 303, and a hot air outlet 304. The high-temperature flue gas inlet 301 is connected to the flue gas main pipe L1, and the hot air outlet 304 is connected to the combustion-supporting gas inlet 223 of the burner 22 through a hot air pipeline L6.

[0037] Thus, the high-temperature flue gas at 800 - 1300 degrees Celsius from the furnace 21 of the combustion unit 20 is discharged to the flue gas main pipe L1. 10 - 30% of the high-temperature flue gas, which accounts for 10 - 30% of the total amount of high-temperature flue gas, is drawn back into the burner 22 through the flue gas branch pipe L5, mixed with high-pressure natural gas and air, and then burned, thereby effectively increasing the furnace temperature and maintaining the stability of the combustion temperature. 70% - 90% of the high-temperature flue gas enters the first heat exchanger 30, exchanges heat with the cold air at 20 - 25 degrees Celsius, and the formed hot air at 500 - 800 degrees Celsius enters the burner 22 through the hot air pipeline L6, mixes with the low-pressure natural gas, and then enters the combustion unit 20 for combustion, further improving the combustion efficiency of the low-pressure natural gas.

[0038] As yet another non-limiting embodiment, as Figure 1 shown, the combustible ice storage unit 10 includes a plurality of heating devices 11, combustible ice containers 12 accommodated in each heating device 11, a common pipe 13 connected to the gas outlet of the combustible ice container 12, and a gas storage tank 14 connected to the outlet of the common pipe 13.

[0039] In this non-limiting embodiment, as Figure 1 shown, the heating device 11 is a water jacket 110 having a hot water inlet 111 and a cold water outlet 112. The hot water inlet 111 and the cold water outlet 112 between two adjacent water jackets 110 are connected through a pipeline L.

[0040] As Figure 1 shown, the second heat exchanger 40 includes a medium-temperature flue gas inlet 401, a low-temperature flue gas outlet 402, a cold water inlet 403, and a hot water outlet 404. The medium-temperature flue gas inlet 401 is connected to the medium-temperature flue gas outlet 302 of the first heat exchanger 30. The low-temperature flue gas outlet 402 is connected to the chimney Y through a low-temperature flue gas pipeline L7. The cold water inlet 403 is connected to the cold water outlet 112 of the water jacket 110 at the end of the combustible ice storage unit 10. The hot water outlet 404 is connected to the hot water inlet 111 of the water jacket at the head end of the combustible ice storage unit 10.

[0041] Thus, the medium-temperature flue gas at 300 - 400 degrees Celsius from the first heat exchanger enters the second heat exchanger 40, exchanges heat with the cold water discharged from the water jacket 110 at the end of the combustible ice storage unit 10 at 30 - 40 degrees Celsius, forms hot water at 80 - 90 degrees Celsius, and then enters the hot water inlet 111 of the water jacket 110 at the head end of the combustible ice storage unit 10, thereby completing the heating of all the combustible ice containers 12. The cold flue gas at 180 - 200 degrees Celsius formed after heat exchange is discharged to the chimney Y through the low-temperature flue gas pipeline L7.

[0042] In this non-limiting embodiment, as Figure 1 shown, a pressure reducing valve P1 is provided on the combustible ice connection pipeline (not labeled in the figure) between the gas outlet of each combustible ice container 12 and the common pipe 13. An electric control valve P2 is provided on the common pipe connection pipeline (not labeled in the figure) between the outlet of the common pipe 13 and the gas storage tank 14. A first fan F1 is provided on the hot air pipeline L6. A second fan F2 is provided on the low-temperature flue gas pipeline L7. The first fan F1, the second fan F2, the pressure reducing valve P1, and the electric control valve P2 are respectively electrically connected to an electric energy storage device (not shown in the figure) to obtain electric energy and realize the closed-loop use of energy.

[0043] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0044] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An efficient combustion system for combustible ice, comprising: Combustible ice storage unit and combustion unit. Among them, a burner is provided at the front end of the furnace of the combustion unit, and a flue gas main pipe for discharging high-temperature flue gas is connected to the rear end of the furnace of the combustion unit. It is characterized in that, The burner is provided with a first gas inlet, a second gas inlet, an auxiliary gas inlet and a combustion gas outlet. A combustion nozzle is provided at the first gas inlet. The combustion nozzle is provided with a first air inlet, a second air inlet, a third air inlet and a mixed gas outlet. Among them, the first air inlet is connected to the combustible ice storage unit through a high-pressure natural gas pipeline, the second air inlet is connected to an air source, and the mixed gas outlet is connected to the first gas inlet of the burner; A natural gas branch line is connected to the high-pressure natural gas pipeline. A gas turbine is provided on the natural gas branch line. The natural gas branch line transports 50% - 60% of the high-pressure natural gas in the high-pressure natural gas pipeline to the gas turbine for power generation, and the generated electric energy is stored in an electric energy storage device. The high-pressure natural gas becomes low-pressure natural gas after passing through the gas turbine and is transported to the second gas inlet of the burner through a low-pressure natural gas pipeline; Among them, the combustible ice storage unit includes a plurality of heating devices, combustible ice containers accommodated in each heating device, a common pipe connected to the gas outlet of the combustible ice container, and a gas storage tank connected to the outlet of the common pipe; Among them, the heating device is a water jacket provided with a hot water inlet and a cold water outlet. The hot water inlet and the cold water outlet between two adjacent water jackets are connected through a pipeline; Among them, the high-efficiency combustible ice combustion system further includes a first heat exchanger. The first heat exchanger includes a high-temperature flue gas inlet, a medium-temperature flue gas outlet, a cold air inlet and a hot air outlet. The high-temperature flue gas inlet is connected to the flue gas main pipe, and the hot air outlet is connected to the auxiliary gas inlet of the burner through a hot air pipeline; Among them, the high-efficiency combustible ice combustion system further includes a second heat exchanger. The second heat exchanger includes a medium-temperature flue gas inlet, a low-temperature flue gas outlet, a cold water inlet and a hot water outlet. The medium-temperature flue gas inlet is connected to the medium-temperature flue gas outlet of the first heat exchanger, the low-temperature flue gas outlet is connected to a chimney through a low-temperature flue gas pipeline, the cold water inlet is connected to the cold water outlet of the water jacket at the end of the combustible ice storage unit, and the hot water outlet is connected to the hot water inlet of the water jacket at the beginning of the combustible ice storage unit.

2. The combustible ice high-efficiency combustion system according to claim 1, characterized in that The flue gas main pipe is connected with a flue gas branch pipe. The flue gas branch pipe is connected to the third air inlet of the combustion nozzle to draw 10% - 30% of the high-temperature flue gas in the flue gas main pipe into the combustion nozzle to be mixed with air and high-pressure natural gas and then sent to the furnace of the combustion unit for combustion.

3. The combustible ice high-efficiency combustion system according to claim 2, characterized in that, The burner includes a coaxial inner cylinder and an outer cylinder. The front ends of the inner cylinder and the outer cylinder are sealed. The rear ends of the inner cylinder and the outer cylinder are the combustion gas outlets, and the combustion gas outlets are communicated with the furnace of the combustion unit. The first gas inlet is opened at the upper side wall of the front end of the outer cylinder, the combustion-supporting gas inlet is opened at the lower side wall of the front end of the inner cylinder, and the second gas inlet is opened at the front end of the inner cylinder.

4. The combustible ice high-efficiency combustion system according to claim 1, characterized in that, A pressure reducing valve is provided on the combustible ice connecting pipeline between the gas outlet of each combustible ice container and the common pipe, and an electric control valve is provided on the common pipe connecting pipeline between the outlet of the common pipe and the gas storage tank.

5. The combustible ice high-efficiency combustion system according to claim 4, characterized in that A first fan is provided on the hot air pipeline to introduce hot air into the combustion-supporting gas inlet, and a second fan is provided on the low-temperature flue gas pipeline to introduce low-temperature flue gas into the chimney.

6. The combustible ice high-efficiency combustion system according to claim 5, characterized in that, The first fan, the second fan, the pressure reducing valve and the electric control valve are respectively electrically connected to the electric energy storage device to obtain electric energy.

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