Multi-energy heat recovery steam supply system for high-temperature molten salt energy storage coupled biomass

Abstract

The utility model discloses a multi-energy heat recovery steam supply system for high-temperature fused salt energy storage coupled biomass. The multi-energy heat recovery steam supply system comprises a biomass gasification reactor, a biomass gasification burner, a high-temperature fused salt heat accumulator, an SCR denitration device, an economizer, an energy saver, a low-temperature fused salt heat accumulator, an evaporator, a cyclone separator, a slag cooler and a medium-temperature fused salt heat accumulator. The biomass gasification reactor is connected with the cyclone separator, the cyclone separator is connected with the biomass gasification burner through the gas fan, and the biomass gasification burner is connected with the high-temperature molten salt heat accumulator through the first heat exchanger; the biomass gasification burner, the SCR denitration device, the coal economizer and the energy saver are connected in sequence, and the energy saver is connected with the low-temperature fused salt heat accumulator through the third heat exchanger; the slag cooler is connected with the biomass gasification reactor and connected with the medium-temperature fused salt heat accumulator through the second heat exchanger, and the evaporator is connected with the high-temperature fused salt heat accumulator, the medium-temperature fused salt heat accumulator and the low-temperature fused salt heat accumulator at the same time. By means of the system, efficient utilization of biomass energy and multi-stage recycling of heat of different grades are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat energy recovery and utilization, and specifically relates to a multi-energy heat recovery steam supply system for high-temperature molten salt energy storage coupled with biomass. Background Art

[0002] Biomass energy is an ideal renewable energy source. Since its net carbon dioxide emissions to the atmosphere during combustion are close to zero, it can effectively reduce the greenhouse effect. Representative biomass includes crops, crop waste, wood, wood waste and animal manure. Modern technology can be used to convert biomass energy into biomass molded fuel, biomass combustible gas, biomass liquid fuel, etc. that can replace fossil fuels. Biomass energy can be directly burned or converted to form solid, gaseous and liquid fuels that are easy to store and transport. It can be burned in most industrial boilers and kilns that use oil, coal and natural gas. However, the existing biomass energy has serious heat loss and low energy utilization efficiency during the utilization process. Therefore, this application proposes a multi-energy heat recovery steam supply system that couples high-temperature molten salt energy storage with biomass. Utility Model Content

[0003] In view of the deficiencies in the prior art, the technical problem that the utility model intends to solve is to provide a multi-energy heat recovery steam supply system of high-temperature molten salt energy storage coupled with biomass.

[0004] The utility model solves the technical problem by adopting the following technical solutions:

[0005] A multi-energy heat recovery steam supply system of high-temperature molten salt energy storage coupled with biomass, comprising a biomass gasification reactor, a biomass gasification burner, a first heat exchanger, a high-temperature molten salt heat accumulator, an SCR denitration device, an economizer, an energy saver, a third heat exchanger, a low-temperature molten salt heat accumulator, an evaporator, a cyclone separator, a slag cooler, a medium-temperature molten salt heat accumulator and a second heat exchanger;

[0006] The gas outlet of the biomass gasification reactor is connected to the gas inlet of the cyclone separator, the discharge port of the cyclone separator is connected to the feed port of the biomass gasification reactor, and the gas outlet of the cyclone separator is connected to the biomass gasification burner through the gas blower; the hot side of the first heat exchanger is connected to the biomass gasification burner, and the cold side is connected to the high-temperature molten salt heat accumulator; the biomass gasification burner, the SCR denitration device, the economizer, the energy saver and the third heat exchanger are connected in sequence, and the cold side of the third heat exchanger is simultaneously connected to the low-temperature molten salt heat accumulator. The evaporator is connected to the slag cooler; the feed port of the slag cooler is connected to the slag discharge port of the biomass gasification reactor, the hot side of the second heat exchanger is connected to the slag cooler, and the cold side is connected to the medium-temperature molten salt heat accumulator; the hot side inlet of the evaporator is connected to the molten salt outlet of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator, respectively, and the hot side outlet is connected to the molten salt inlets of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator, respectively, and the cold side inlet and cold side outlet of the evaporator are connected to the external water supply device and the user end respectively.

[0007] Furthermore, the first heat exchanger, the second heat exchanger and the third heat exchanger are all provided with a driving pump.

[0008] Furthermore, valves and molten salt pumps are provided on the outlet pipes of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator, and valves are provided on the inlet pipes of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator.

[0009] Furthermore, the biomass gasification reactor and the biomass gasification burner are both connected to a blower.

[0010] Furthermore, an induced draft fan is provided between the economizer and the third heat exchanger, and a tube bundle dust removal and desulfurization device is provided between the economizer and the induced draft fan.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] The heat generated by the combustion of combustible gas in the biomass gasification burner and the heat of high-temperature flue gas are exchanged with molten salt to achieve heat storage and utilization. At the same time, the economizer and energy saver are used to recover the waste heat of the high-temperature flue gas generated by the biomass gasification burner, further reducing the exhaust temperature, improving the waste heat utilization efficiency of the biomass gasification burner, and realizing efficient utilization of the thermal energy of biomass gasification.

[0013] Compared with traditional furnace types, the biomass gasification reactor has the characteristics of low gas velocity, large heat storage pool, and long residence time of feed in the high temperature zone. It can cope with fluctuations in raw material components and reduce the entry of K and Na into the downstream gas phase to a certain extent. The cyclone separator can solve the tar decomposition and return the tar-free solid particle fuel to the biomass gasification reactor for gasification reaction, which improves the utilization rate of biomass fuel and makes it fully burned cleanly, so that the entire system is tar-free outside and the operation site is clean and tidy.

[0014] Compared with the traditional process, this system treats the ash produced by the biomass gasification reactor more fully and recovers the waste heat. After granulation, the ash enters the slag cooler for waste heat recovery. The recovered heat is stored in the molten salt of the medium-temperature molten salt accumulator through the second heat exchanger.

[0015] The large amount of heat generated by the biomass gasification burner is exchanged with the molten salt in the high-temperature molten salt heat accumulator. The heat generated after the ash enters the slag cooler is exchanged with the molten salt in the medium-temperature molten salt heat accumulator. The tail flue gas is exchanged with the molten salt in the low-temperature molten salt heat accumulator, realizing multi-stage recovery and utilization of heat of different grades. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model;

[0017] Among them: 1-biomass gasification reactor; 2-blower; 3-gas blower; 4-burner blower; 5-biomass gasification burner; 6-first heat exchanger; 7-high-temperature molten salt heat accumulator; 8-SCR denitrification device; 9-economizer; 10-energy saver; 11-induced draft fan; 12-third heat exchanger; 13-low-temperature molten salt heat accumulator; 14-evaporator; 15-cyclone separator; 16-slag cooler; 17-medium-temperature molten salt heat accumulator; 18-second heat exchanger. DETAILED DESCRIPTION

[0018] Specific embodiments are given below in conjunction with the accompanying drawings. The specific embodiments are only used to further describe the technical solution of the utility model in detail, but are not intended to limit the protection scope of the present application.

[0019] The utility model provides a high-temperature molten salt energy storage coupled with a biomass multi-energy heat recovery steam supply system (referred to as the system, see Figure 1 ), including a biomass gasification reactor 1, a blower 2, a gas blower 3, a burner blower 4, a biomass gasification burner 5, a first heat exchanger 6, a high-temperature molten salt heat accumulator 7, an SCR denitration device 8, an economizer 9, an energy saver 10, a third heat exchanger 12, a low-temperature molten salt heat accumulator 13, an evaporator 14, a cyclone separator 15, a slag cooler 16, a medium-temperature molten salt heat accumulator 17 and a second heat exchanger 18;

[0020] The lower end of the biomass gasification reactor 1 is connected to a blower 2 to introduce air into the biomass gasification reactor 1. The gas outlet at the upper part of the biomass gasification reactor 1 is connected to the inlet of the cyclone separator 15 through a gas pipeline. The gas outlet at the upper end of the cyclone separator 15 is connected to the gas inlet of the biomass gasification burner 5 through a gas blower 3. The discharge port at the lower end of the cyclone separator 15 is connected to the feed port in the middle of the biomass gasification reactor 1. The solid particle fuel separated by the cyclone separator 15 is sent to the biomass gasification reactor 1 for gasification reaction again. The gas inlet of the biomass gasification burner 5 is also connected to the burner blower 4. The burner blower 4 introduces air into the biomass gasification burner 5, so that the air and the combustible gas generated by the biomass gasification reactor 1 undergo a combustion reaction; the hot side of the first heat exchanger 6 is connected to the biomass gasification burner 5, and the cold side of the first heat exchanger 6 is connected to the high-temperature molten salt heat accumulator 7, and the heat generated by the combustion reaction in the biomass gasification burner 5 is stored in the molten salt of the high-temperature molten salt heat accumulator 7 through the first heat exchanger 6; the inlet of the SCR denitrification device 8 is connected to the flue gas outlet of the biomass gasification burner 5, the outlet of the SCR denitrification device 8 is connected to the inlet of the economizer 9, the inlet of the economizer 10 is connected to the outlet of the economizer 9, and the economizer 10 is connected to the outlet of the economizer 9. The outlet of the induced draft fan 11 is connected to the inlet of the third heat exchanger 12, the outlet of the third heat exchanger 12 is connected to the atmosphere, and the main part of the third heat exchanger 12 is located in the low-temperature molten salt heat accumulator 13; the high-temperature flue gas generated by the biomass gasification burner 5 is denitrified by the SCR denitration device 8, and then passes through the economizer 9 and the energy saver 10 in turn to reduce the exhaust gas temperature, and finally exchanges heat with the molten salt in the low-temperature molten salt heat accumulator 13 to store heat in the molten salt; the hot side inlet of the evaporator 14 is connected to the high-temperature molten salt heat accumulator 7 and the molten salt outlet of the low-temperature molten salt heat accumulator 13 through a pipeline, and the evaporator 14 The hot side outlet is connected to the molten salt inlet of the high-temperature molten salt accumulator 7 and the low-temperature molten salt accumulator 13 through a pipeline, and the cold side inlet and cold side outlet of the evaporator 14 are respectively connected to the external water supply device and the user end; the ash produced by the combustion of the biomass raw material is discharged from the slag discharge port at the bottom of the biomass gasification reactor 1, and after granulation treatment, it enters the slag cooler 16; the hot side of the second heat exchanger 18 is connected to the slag cooler 16, and the cold side is connected to the medium-temperature molten salt accumulator 17, the molten salt outlet of the medium-temperature molten salt accumulator 17 is connected to the hot side inlet of the evaporator 14 through a pipeline, and the molten salt inlet of the medium-temperature molten salt accumulator 17 is connected to the hot side outlet of the evaporator 14 through a pipeline.

[0021] Furthermore, the first heat exchanger 6, the second heat exchanger 18 and the third heat exchanger 12 are provided with driving pumps for driving the heat exchange medium to circulate in the heat exchangers.

[0022] Furthermore, valves and molten salt pumps are provided on the outlet pipes of the high-temperature molten salt heat accumulator 7, the medium-temperature molten salt heat accumulator 17 and the low-temperature molten salt heat accumulator 13, valves are also provided on the inlet pipes of the high-temperature molten salt heat accumulator 7, the medium-temperature molten salt heat accumulator 17 and the low-temperature molten salt heat accumulator 13, and a master control valve is provided on the main pipe to control the cutting off of the molten salt flow.

[0023] Furthermore, the high-temperature molten salt heat accumulator 7, the medium-temperature molten salt heat accumulator 17 and the low-temperature molten salt heat accumulator 13 are provided with a thermometer and a pressure gauge for detecting the temperature and pressure of the heat accumulator.

[0024] Furthermore, a tube bundle dust removal and desulfurization device is provided between the economizer 10 and the induced draft fan 11 to further remove dust and purify the flue gas.

[0025] The working principle and workflow of the utility model are:

[0026] The biomass raw material enters the biomass gasification reactor 1 from the feed port at the upper end, and the blower 2 at the lower end passes air into the biomass gasification reactor 1. Under certain thermodynamic conditions, the biomass raw material undergoes pyrolysis, oxidation, reduction and reforming reactions with the help of air and water vapor, and is converted into combustible gases containing carbon monoxide, hydrogen and low molecular hydrocarbons. The ash produced by the combustion of the biomass raw material is discharged through the slag discharge port at the bottom of the biomass gasification reactor 1 and enters the slag cooler 16 for slag cooling after the granulation process. The heat in the ash is transferred to the molten salt in the medium-temperature molten salt heat accumulator 17 through the second heat exchanger 18 for storage. The combustible gas produced by the biomass gasification reactor 1 is separated into gas and solid through the cyclone separator 15, and the separated solid particle fuel is returned to the biomass gasification reactor 1 for gasification reaction again, and the combustible gas is then passed through the gas blower 3 to enter The biomass gasification burner 5 is fed into the biomass gasification burner 5, and air is introduced into the biomass gasification burner 5 through the burner blower 4. The air and the combustible gas react with each other, and a large amount of heat generated is exchanged with the molten salt in the high-temperature molten salt heat accumulator 7 through the first heat exchanger 6, so that the temperature of the molten salt is increased to achieve heat storage; the high-temperature flue gas generated by the biomass gasification burner 5 is purified by the SCR denitrification device 8, and then passes through the economizer 9 and the energy saver 10 in sequence to recover the heat in the high-temperature flue gas and reduce the exhaust temperature. The recovered heat is used to heat the feed water of the biomass gasification burner 5. The cooled flue gas passes through the tube bundle for dust removal and desulfurization, and then enters the third heat exchanger 12 through the induced draft fan 11 to exchange heat with the molten salt in the low-temperature molten salt heat accumulator 13, and the heat is stored in the molten salt of the low-temperature molten salt heat accumulator 13, so as to further reduce the exhaust temperature. The further cooled flue gas is finally discharged into the atmosphere.

[0027] When the user end needs steam supply, the high-temperature molten salt heat accumulator 7 is first used to provide heat to the evaporator 14, that is, the valve on the outlet pipe of the high-temperature molten salt heat accumulator 7, the molten salt pump and the valve on the inlet pipe are opened, and the molten salt in the high-temperature molten salt heat accumulator 7 enters the evaporator 14 to exchange heat with the water in the evaporator 14, and the molten salt after heat exchange is returned to the high-temperature molten salt heat accumulator 7, and the steam generated by the evaporator 14 is supplied to the user end through the outlet. After the heat of the high-temperature molten salt heat accumulator 7 is fully utilized, the valve on the outlet pipe of the high-temperature molten salt heat accumulator 7, the molten salt pump and the valve on the inlet pipe are closed, and the medium-temperature molten salt heat accumulator 17 is switched to provide heat to the evaporator 14, that is, the valve on the outlet pipe of the medium-temperature molten salt heat accumulator 17, the molten salt pump and the valve on the inlet pipe are opened, and the molten salt in the medium-temperature molten salt heat accumulator 17 enters the evaporator 14 for heat exchange, and the molten salt after heat exchange is returned to the medium-temperature molten salt heat accumulator 17. After the heat utilization of the medium-temperature molten salt heat accumulator 17 is completed, the valve on the outlet pipe of the medium-temperature molten salt heat accumulator 17, the molten salt pump and the valve on the inlet pipe are closed, and the low-temperature molten salt heat accumulator 13 is switched to provide heat to the evaporator 14, that is, the valve on the outlet pipe of the low-temperature molten salt heat accumulator 13, the molten salt pump and the valve on the inlet pipe are opened, and the molten salt in the low-temperature molten salt heat accumulator 13 enters the evaporator 14 for heat exchange, and the molten salt after heat exchange is returned to the low-temperature molten salt heat accumulator 13.

[0028] Anything not described in the present invention is applicable to the prior art.

Claims

1. A high-temperature molten salt energy storage coupled with biomass multi-energy heat recovery steam supply system, characterized in that: The system includes a biomass gasification reactor, a biomass gasification burner, a first heat exchanger, a high-temperature molten salt heat accumulator, an SCR denitration device, an economizer, an energy saver, a third heat exchanger, a low-temperature molten salt heat accumulator, an evaporator, a cyclone separator, a slag cooler, a medium-temperature molten salt heat accumulator and a second heat exchanger; The gas outlet of the biomass gasification reactor is connected to the gas inlet of the cyclone separator, the discharge port of the cyclone separator is connected to the feed port of the biomass gasification reactor, and the gas outlet of the cyclone separator is connected to the biomass gasification burner through the gas blower; the hot side of the first heat exchanger is connected to the biomass gasification burner, and the cold side is connected to the high-temperature molten salt heat accumulator; the biomass gasification burner, the SCR denitration device, the economizer, the energy saver and the third heat exchanger are connected in sequence, and the cold side of the third heat exchanger is simultaneously connected to the low-temperature molten salt heat accumulator. The evaporator is connected to the slag cooler; the feed port of the slag cooler is connected to the slag discharge port of the biomass gasification reactor, the hot side of the second heat exchanger is connected to the slag cooler, and the cold side is connected to the medium-temperature molten salt heat accumulator; the hot side inlet of the evaporator is connected to the molten salt outlet of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator, respectively, and the hot side outlet is connected to the molten salt inlets of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator, respectively, and the cold side inlet and cold side outlet of the evaporator are connected to the external water supply device and the user end respectively.

2. The high-temperature molten salt energy storage coupled with biomass multi-energy heat recovery steam supply system according to claim 1 is characterized in that: The first heat exchanger, the second heat exchanger and the third heat exchanger are all provided with a driving pump.

3. The high-temperature molten salt energy storage coupled with biomass multi-energy heat recovery steam supply system according to claim 1 or 2, characterized in that: The outlet pipes of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator are provided with valves and molten salt pumps, and the inlet pipes of the high-temperature molten salt heat accumulator, the medium-temperature molten salt heat accumulator and the low-temperature molten salt heat accumulator are provided with valves.

4. The high-temperature molten salt energy storage coupled with biomass multi-energy heat recovery steam supply system according to claim 1 is characterized in that: The biomass gasification reactor and the biomass gasification burner are both connected with a blower.

5. The high-temperature molten salt energy storage coupled with biomass multi-energy heat recovery steam supply system according to claim 1 or 4, characterized in that: An induced draft fan is arranged between the economizer and the third heat exchanger, and a tube bundle dust removal and desulfurization device is arranged between the economizer and the induced draft fan.

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