Biogas-tower type photo-thermal complementary power generation system
阅读说明:本技术 一种沼气-塔式光热互补的发电系统 (Biogas-tower type photo-thermal complementary power generation system ) 是由 纪培栋 李心 章涵 罗小强 于 2019-09-24 设计创作,主要内容包括:本发明提供了一种沼气-塔式光热互补的发电系统,包括塔式聚光吸热系统、熔盐储能系统、熔盐蒸汽发生系统、汽轮机组发电系统、沼气发酵系统、沼气熔盐加热系统、沼气过热系统、沼气发酵增温系统;其中:塔式聚光吸热系统,用于将其内部流动的低温熔盐加热为高温熔盐;熔盐储能系统用于提供高温熔盐和低温熔盐;熔盐蒸汽发生系统利用高温熔盐产生过热蒸汽;该述过热蒸汽经过汽轮机组发电系统后冷凝为液体水;沼气发酵系统用于提供沼气;沼气熔盐加热系统用于燃烧沼气加热低温熔盐;沼气过热系统用于燃用沼气加热过热蒸汽。本发明既解决了连续阴雨天气条件下塔式光热电站无法发电的问题,又解决了低温条件下沼气发酵产气率低的问题。(The invention provides a biogas-tower type photo-thermal complementary power generation system, which comprises a tower type light-gathering and heat-absorbing system, a molten salt energy storage system, a molten salt steam generation system, a steam turbine unit power generation system, a biogas fermentation system, a biogas molten salt heating system, a biogas overheating system and a biogas fermentation heating system, wherein the tower type light-gathering and heat-absorbing system is connected with the molten salt energy storage system; wherein: the tower type light-gathering and heat-absorbing system is used for heating low-temperature molten salt flowing inside the tower type light-gathering and heat-absorbing system into high-temperature molten salt; the molten salt energy storage system is used for providing high-temperature molten salt and low-temperature molten salt; the molten salt steam generation system generates superheated steam by using high-temperature molten salt; the superheated steam is condensed into liquid water after passing through a steam turbine set power generation system; the biogas fermentation system is used for providing biogas; the methane molten salt heating system is used for burning methane to heat low-temperature molten salt; the methane overheating system is used for burning methane to heat the overheated steam. The invention not only solves the problem that the tower type photo-thermal power station cannot generate power under the condition of continuous rainy weather, but also solves the problem that the biogas fermentation gas production rate is low under the condition of low temperature.)
1. A biogas-tower photo-thermal complementary power generation system comprises a tower type light-gathering and heat-absorbing system, a molten salt energy storage system, a molten salt steam generation system and a turbine unit power generation system, and is characterized by further comprising a biogas fermentation system, a biogas molten salt heating system, a biogas overheating system and a biogas fermentation heating system; wherein:
the tower type light-gathering and heat-absorbing system is used for heating low-temperature molten salt flowing inside the tower type light-gathering and heat-absorbing system into high-temperature molten salt;
the molten salt energy storage system comprises: a high-temperature molten salt storage tank and a low-temperature molten salt storage tank; the low-temperature molten salt storage tank is used for providing low-temperature molten salt for the tower type light-gathering heat absorption system; the high-temperature molten salt storage tank is used for providing high-temperature molten salt for the molten salt steam generation system;
the molten salt steam generation system generates superheated steam by using the heat of high-temperature molten salt; the superheated steam is condensed into liquid water after passing through the steam turbine set power generation system;
the biogas fermentation system is used for providing biogas, and comprises: the biogas fermentation tank is used for generating biogas, and the gas storage cabinet is used for storing the biogas; the biogas fermentation tank is connected with the gas storage cabinet; the gas storage cabinet is respectively connected with the methane molten salt heating system and the methane overheating system;
the methane molten salt heating system is used for burning methane to heat low-temperature molten salt and comprises a first valve group and a methane-burning molten salt heating furnace; the first valve group is respectively connected with the molten salt heating furnace and the molten salt energy storage system and is used for controlling the molten salt to flow to the tower type light-gathering and heat-absorbing system or the molten salt heating furnace; the molten salt heating furnace is respectively connected with the gas storage cabinet and the molten salt energy storage system;
the methane overheating system is used for burning methane to heat the overheated steam; the system is respectively connected with a fused salt steam generation system, a steam turbine set power generation system and a gas storage cabinet;
the methane fermentation warming system comprises a second valve group and a heating device; the second valve group is respectively connected with the steam turbine set power generation system and the heating device; the valve group is used for controlling liquid water at the outlet of the steam turbine set power generation system to enter a heating device or a molten salt steam generation system; the heating device is arranged inside the biogas fermentation tank and used for increasing the fermentation temperature inside the biogas fermentation tank.
2. The biogas-tower type photo-thermal complementary power generation system as claimed in claim 1, wherein the temperature of the low-temperature molten salt at the inlet of the tower type light-gathering and heat-absorbing system is 260-320 ℃, and the temperature of the high-temperature molten salt at the outlet of the tower type light-gathering and heat-absorbing system is 400-600 ℃.
3. The biogas-tower photothermal complementary power generation system according to claim 1 or 2, wherein the molten salt comprises one or more of NaNO3, KNO3, NaCl, KCl, Na2CO3, and K2CO 3.
4. The biogas-tower photothermal complementary power generation system of claim 1 further comprising: a low-temperature molten salt pump and a high-temperature molten salt pump; the low-temperature molten salt pump is connected with the low-temperature molten salt storage tank, the high-temperature molten salt pump is connected with the high-temperature molten salt storage tank, and the types of the low-temperature molten salt pump and the high-temperature molten salt pump include but are not limited to a vertical pump and a horizontal pump; the first valve group is arranged at the outlet of the low-temperature molten salt pump.
5. The biogas-tower type photo-thermal complementary power generation system according to claim 1, wherein the design power of the biogas molten salt heating system is calculated by the following formula: (specific heat capacity of high-temperature molten salt x temperature of high-temperature molten salt-specific heat capacity of low-temperature molten salt x temperature of low-temperature molten salt) x rated molten salt flow of the molten salt steam generation system.
6. The biogas-tower photothermal complementary power generation system according to claim 1, wherein the design power of the biogas superheating system is calculated by the following formula: (rated steam inlet specific heat capacity of the steam turbine generator unit multiplied by rated steam inlet temperature-400 ℃ water steam specific heat capacity multiplied by (400+273)) × rated steam inlet flow rate of the steam turbine generator unit.
7. The biogas-tower-type photo-thermal complementary power generation system according to claim 1, wherein the heating device of the biogas fermentation warming system is in the form of, but not limited to, a U-shaped pipe or a coil pipe, and is installed inside the biogas fermentation tank; the liquid water at the outlet of the steam turbine set power generation system flows in from the inlet of the heating device, releases heat in the biogas fermentation tank to heat the fermentation liquid of the biogas fermentation tank, raises the temperature of the biogas fermentation tank to 40-60 ℃, and then flows out from the outlet of the heating device.
8. The biogas-tower-type photothermal complementary power generation system according to claim 1, wherein the biogas fermentation tank can be located above ground or below ground; the working pressure of the gas storage cabinet is 0-3000 Pa.
9. The biogas-tower-type photo-thermal complementary power generation system of claim 1, wherein the molten salt steam generation system comprises a preheater, an evaporator, a steam drum, a superheater; feed water is sent into the preheater through a feed pump and is preliminarily heated by high-temperature molten salt, then the feed water enters the evaporator and is changed into a steam-water mixture from liquid water, the steam-water mixture enters the steam drum to be subjected to gas-liquid separation, and the separated steam enters the superheater and is heated into superheated steam.
Technical Field
The invention relates to the technical field of solar power generation, in particular to a biogas-tower type photo-thermal complementary power generation system.
Background
The tower type photo-thermal power generation technology is greatly popularized due to the advantages of high condensation ratio, high operation parameters, high photoelectric efficiency and easy energy storage. The tower type photo-thermal power station is mostly built in areas with better solar illumination resources, such as parts of Qinghai, Gansu and Xinjiang in China. In these areas, the aquaculture is developed, and meanwhile, the agricultural and forestry wastes are more, so that the biogas fermentation system is suitable for being constructed.
The energy storage time of the tower type photo-thermal power station is generally 6 to 16 hours, continuous and stable power supply cannot be provided for a power grid or a power consumption owner in continuous rainy weather, or the energy storage time is shortened because the energy storage medium cannot reach the design temperature or the design temperature in order to reach the design temperature when the sun illumination cannot reach the design condition of the tower type photo-thermal power station, so that the energy needs to be supplemented for the tower type photo-thermal power station; because the solar light cannot reach the design value, the heat storage medium cannot reach the design temperature, and the temperature parameter of the superheated steam generated by the steam generation system cannot reach the steam inlet temperature required by the steam turbine generator unit, the superheated steam generated by the steam generation system needs to be heated before entering the steam turbine, and the superheated steam is ensured to reach the steam inlet temperature required by the steam turbine.
Meanwhile, a biogas fermentation system needs a proper fermentation temperature, but the biogas fermentation temperature is difficult to ensure in northwest China due to cold climate, so that the gas yield is low.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a methane-tower type photo-thermal complementary power generation system, which utilizes dead steam of a tower type photo-thermal power station to provide a heat source for methane, improves the methane yield, and provides energy for the tower type photo-thermal power station by utilizing the methane, thereby ensuring that the tower type photo-thermal power station can continuously and stably operate. The invention solves the problem that the tower type photo-thermal power station cannot generate power under the condition of continuous rainy weather, and simultaneously solves the problem of low methane production rate of methane fermentation under the condition of low temperature. The technical scheme of the invention is as follows:
a biogas-tower photo-thermal complementary power generation system comprises a tower type light-gathering and heat-absorbing system, a molten salt energy storage system, a molten salt steam generation system and a turbine unit power generation system, and is characterized by further comprising a biogas fermentation system, a biogas molten salt heating system, a biogas overheating system and a biogas fermentation heating system; wherein:
the tower type light-gathering and heat-absorbing system is used for heating low-temperature molten salt flowing inside the tower type light-gathering and heat-absorbing system into high-temperature molten salt;
the molten salt energy storage system comprises: a high-temperature molten salt storage tank and a low-temperature molten salt storage tank; the low-temperature molten salt storage tank is used for providing low-temperature molten salt for the tower type light-gathering heat absorption system; the high-temperature molten salt storage tank is used for providing high-temperature molten salt for the molten salt steam generation system;
the molten salt steam generation system generates superheated steam by using the heat of high-temperature molten salt; the superheated steam is condensed into liquid water after passing through the steam turbine set power generation system;
the biogas fermentation system is used for providing biogas, and comprises: the biogas fermentation tank is used for generating biogas, and the gas storage cabinet is used for storing the biogas; the biogas fermentation tank is connected with the gas storage cabinet; the gas storage cabinet is respectively connected with the methane molten salt heating system and the methane overheating system;
the methane molten salt heating system is used for burning methane to heat low-temperature molten salt and comprises a first valve group and a methane-burning molten salt heating furnace; the first valve group is respectively connected with the molten salt heating furnace and the molten salt energy storage system and is used for controlling the molten salt to flow to the tower type light-gathering and heat-absorbing system or the molten salt heating furnace; the molten salt heating furnace is respectively connected with the gas storage cabinet and the molten salt energy storage system;
the methane overheating system is used for burning methane to heat the overheated steam; the system is respectively connected with a fused salt steam generation system, a steam turbine set power generation system and a gas storage cabinet;
the methane fermentation warming system comprises a second valve group and a heating device; the second valve group is respectively connected with the steam turbine set power generation system and the heating device; the valve group is used for controlling liquid water at the outlet of the steam turbine set power generation system to enter a heating device or a molten salt steam generation system; the heating device is arranged inside the biogas fermentation tank and used for increasing the fermentation temperature inside the biogas fermentation tank.
Further, the temperature of the low-temperature molten salt at the inlet of the tower type light-gathering and heat-absorbing system is 260-320 ℃, and the temperature of the high-temperature molten salt at the outlet of the tower type light-gathering and heat-absorbing system is 400-600 ℃.
Further, the component of the molten salt is NaNO3、KNO3、NaCl、KCl、Na2CO3、K2CO3One or more mixtures thereof.
Further, the low-temperature molten salt pump is connected with the low-temperature molten salt storage tank, the high-temperature molten salt pump is connected with the high-temperature molten salt storage tank, and the types of the low-temperature molten salt pump and the high-temperature molten salt pump include, but are not limited to, a vertical pump and a horizontal pump.
Further, the design power of the methane molten salt heating system is calculated by the following formula: (specific heat capacity of high-temperature molten salt x temperature of high-temperature molten salt-specific heat capacity of low-temperature molten salt x temperature of low-temperature molten salt) x rated molten salt flow of the molten salt steam generation system.
Further, the design power of the methane overheating system is calculated by the following formula: (rated steam inlet specific heat capacity of the steam turbine generator unit multiplied by rated steam inlet temperature-400 ℃ water steam specific heat capacity multiplied by (400+273)) × rated steam inlet flow rate of the steam turbine generator unit.
Further, the heating device of the biogas fermentation warming system is in a form including, but not limited to, a U-shaped pipe or a coil pipe, and is installed inside the biogas fermentation tank. Liquid water at the outlet of the steam turbine set power generation system flows in from the inlet of the heating device, releases heat in the biogas fermentation tank to heat fermentation liquor of the biogas fermentation tank, and then flows out from the outlet of the heating device.
Further, the biogas fermentation tank can be located on the ground or underground. The working pressure of the gas storage cabinet is 0-3000 Pa.
Further, the molten salt steam generation system comprises a preheater, an evaporator, a steam drum and a superheater; feed water is sent into the preheater through a feed pump and is preliminarily heated by high-temperature molten salt, then the feed water enters the evaporator and is changed into a steam-water mixture from liquid water, the steam-water mixture enters the steam drum to be subjected to gas-liquid separation, and the separated steam enters the superheater and is heated into superheated steam.
Compared with the prior art, the invention has the following beneficial effects: the invention utilizes the renewable clean energy of the methane, solves the problem that the tower type photo-thermal power generation cannot generate power in continuous rainy weather, ensures that the photo-thermal power station can continuously and stably provide power, solves the problem of low temperature of superheated steam at the inlet of the turbo generator unit, simultaneously utilizes the exhaust steam at the outlet of the turbo generator unit to improve the temperature of the methane fermentation tank, solves the problem of low methane yield caused by low temperature, and simultaneously realizes the gradient utilization of energy.
Drawings
Fig. 1 is a schematic diagram of a biogas-tower type photo-thermal complementary power generation system according to an embodiment of the invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
The invention is described in further detail below with reference to the specific embodiment of fig. 1.
A biogas-tower photo-thermal complementary power generation system comprises a tower type light-gathering and heat-absorbing system 1, a molten salt energy storage system 2, a molten salt steam generation system 3, a turbine unit power generation system 4, a biogas fermentation system 5, a biogas molten salt heating system 6, a biogas overheating system 7 and a biogas
the tower type light-gathering heat absorption system 1 comprises a heliostat field 11 and a tower type
The temperature of the low-temperature molten salt at the inlet of the tower type light-gathering and heat-absorbing system is 260-320 ℃, and the temperature of the high-temperature molten salt at the outlet of the tower type light-gathering and heat-absorbing system is 400-600 ℃.
The molten salt comprises one or more of NaNO3, KNO3, NaCl, KCl, Na2CO3 and K2CO 3.
The molten salt energy storage system 2 comprises a low-temperature molten salt storage tank 22, a high-temperature molten salt storage tank 21, a low-temperature molten salt pump and a high-temperature molten salt pump. The low-temperature molten salt pump is connected with the low-temperature molten salt storage tank, the high-temperature molten salt pump is connected with the high-temperature molten salt storage tank, and the types of the low-temperature molten salt pump and the high-temperature molten salt pump include but are not limited to a vertical pump and a horizontal pump; the low-temperature molten salt storage tank is used for providing low-temperature molten salt for the tower type light-gathering heat absorption system; the high-temperature molten salt storage tank is used for providing high-temperature molten salt for the molten salt steam generation system;
the low-temperature molten salt storage tank stores low-temperature molten salt, and the low-temperature molten salt pump sends the low-temperature molten salt in the low-temperature molten salt storage tank to the inlet of the tower type heat absorption system; the high-temperature molten salt storage tank stores high-temperature molten salt, and the molten salt flows out from the outlet of the tower-type light-gathering and heat-absorbing system to the high-temperature molten salt storage tank for storage. And the high-temperature molten salt pump sends high-temperature molten salt to the molten salt steam generation system.
The molten salt steam generation system 3 generates superheated steam by using the heat of high-temperature molten salt; the superheated steam is condensed into liquid water after passing through the steam turbine set power generation system; wherein:
the molten salt steam generation system 3 comprises a preheater, an evaporator, a steam drum and a superheater. Feed water is sent into the preheater through a feed pump and is preliminarily heated by high-temperature molten salt, then the feed water enters the evaporator and is changed into a steam-water mixture from liquid water, the steam-water mixture enters the steam drum to be subjected to gas-liquid separation, and the separated steam enters the superheater and is heated into superheated steam.
The superheated steam enters the steam turbine set power generation system 4 to do work to generate electric energy, the superheated steam after doing work is condensed into liquid water, and then the liquid water enters the molten salt steam generation system 3 to complete the whole thermodynamic cycle.
The steam turbine unit power generation system 4 includes a steam turbine generator unit.
The biogas fermentation system 5 is used for providing biogas, and comprises: a biogas fermentation tank 51 for generating biogas, a
The biogas fermentation tank 51 can be located above the ground or below the ground; the working pressure of the gas storage cabinet is 0-3000 Pa.
The methane molten salt heating system is used for burning methane to heat low-temperature molten salt and comprises a first valve group and a methane-burning molten salt heating furnace; the system is used for controlling the molten salt to flow to a tower type light-gathering heat-absorbing system or a molten salt heating furnace;
the marsh gas molten salt heating system 6 comprises a
The design power of the methane molten salt heating system 6 is calculated by the following formula: (specific heat capacity of high-temperature molten salt x temperature of high-temperature molten salt-specific heat capacity of low-temperature molten salt x temperature of low-temperature molten salt) x rated molten salt flow of the molten salt steam generation system.
The methane overheating system 7 is used for burning methane to heat the overheated steam; which are respectively connected with the fused salt steam generating system 3, the steam turbine set generating system 4 and the
The design power of the methane overheating system is calculated by the following formula: (rated steam inlet specific heat capacity of the steam turbine generator unit multiplied by rated steam inlet temperature-400 ℃ water steam specific heat capacity multiplied by (400+273)) × rated steam inlet flow rate of the steam turbine generator unit.
The biogas
The solar-thermal power station focuses sunlight to the
The biogas fermentation system 5 produces biogas by fermenting human, livestock and poultry manure, agricultural and forestry waste and the like in the biogas fermentation tank 51, and the produced biogas enters the
The marsh gas molten salt heating system 6 consists of a
The methane overheating system 7 burns methane to heat the overheated steam. After the superheated steam flows out of the molten salt steam generation system 7, if the temperature is lower than the inlet steam temperature required by the steam turbine unit power generation system 4, the methane superheating system 7 is started, the low-temperature superheated steam is heated into high-temperature superheated steam meeting the requirements of the steam turbine unit, and then the high-temperature superheated steam enters the steam turbine unit power generation system 4 to do work.
The biogas
When the sunlight is continuously weak for several hours and the liquid level in the high-temperature molten salt storage tank 21 is low and cannot meet the operation requirement of the system, the marsh gas molten salt heating system 6 is started, marsh gas flows out of the
When the temperature of the high-temperature high-pressure steam at the outlet of the fused salt steam generation system 3 is lower than the steam temperature required by the steam turbine unit power generation system 4, the methane superheating system 7 is started to heat the steam at the outlet of the fused salt steam generation system 3 into the high-temperature steam meeting the requirements of the steam turbine unit.
The system of the embodiment utilizes the exhaust steam of the tower type photo-thermal power station to provide a heat source for the methane, improves the methane yield of the methane, and simultaneously utilizes the methane to provide energy for the tower type photo-thermal power station, thereby ensuring that the tower type photo-thermal power station can continuously and stably operate. The problem that the tower type photo-thermal power station cannot generate power under the continuous rainy weather condition is solved, and the problem that the biogas fermentation gas production rate is low under the low-temperature condition is solved.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.