English:
[0001] Embodiments of the invention relate generally to air compression and expansion systems and, more particularly, to a system and method for carbon dioxide capture in an air compression and expansion system.
[0002] Air compression and expansion systems are used in a multitude of industries for a variety of applications. For example, one such application is the use of air compression and expansion systems as the turbomachinery in generating and storing energy. Compressed air energy storage (CAES) systems typically include a compression train having one or more compressors that compress intake air and provide the compressed intake air to a cavern, underground storage, or other compressed air storage component. The compressed air is then later used to drive one or more turbines to produce energy, such as, for example, electrical energy. During operation of the compression stage of a CAES system, the compressed intake air is typically cooled to cavern temperature prior to storage. During operation of the expansion stage, air is discharged from underground storage through turbines and expands such that the air exits the turbines at ambient pressure.
[0003] CAES systems are effective contributors to a utility plant's power generation mix as a source of injecting energy into the grid during peak power times, while storing excess energy during off-peak hours. CAES systems may also use energy generated from wind mills to power the compression train while compressed air is delivered to the energy storage cavern or the like.
[0004] While CAES systems may improve the efficiency of energy generation and/or provide auxiliary energy to the grid during peak hours, utility plants (e.g., coal and natural gas power plants) generate large amounts of carbon dioxide (C02) that contributes to atmospheric greenhouse gases.
[0005] Therefore, it would be desirable to design a system and method that reduce C02contributions from a CAES system implemented in a utility plant.
[0006] Embodiments of the invention are directed to a system and method for carbon dioxide capture in an air compression and expansion system.
[0007] Therefore, in accordance with one aspect of the invention, a gas compression and expansion system includes a compression system fluidly coupled to a storage compartment and configured to compress a first quantity of gas for storage in the storage compartment, the compression system including a compression path configured to convey the first quantity of gas therethrough. The gas compression and expansion system also includes an expansion system fluidly coupled to the storage compartment and configured to expand a second quantity of gas from the storage compartment, the expansion system including an expansion path configured to convey the second quantity of gas therethrough. Further, the gas compression and expansion system includes a first path fluidly coupled to the compression path and configured to convey the first quantity of gas to the storage compartment, a second path fluidly coupled to the expansion path and configured to convey the second quantity of gas from the storage compartment to the expansion system, and a carbon dioxide separation unit fluidly coupled to one of the first path, the second path, the compression path, and the expansion path, wherein the carbon dioxide separation unit is configured to remove a quantity of carbon dioxide from one of the first quantity of gas and the second quantity of gas.
[0008] In accordance with another aspect of the invention, a method of manufacturing an air compression and expansion system includes configuring a compressor to compress an airstream for storage in a storage volume, coupling a first airflow path to the compressor and configuring the first airflow path to deliver a compressed airstream to the storage volume, and configuring a turbine to receive a quantity of the compressed airstream and expand the quantity of the compressed airstream. The method also includes coupling a second airflow path to the turbine and configuring the second airflow path to deliver the quantity of the compressed airstream to the turbine from the storage volume and coupling a carbon dioxide filter along at least one of the first airflow path and the second airflow path and configuring the carbon dioxide filter to filter a quantity of carbon dioxide from the compressed airstream.
[0009] In accordance with another aspect of the invention, a compressed air energy storage (CAES) system includes a compressor assembly having an inlet and an outlet, the compressor configured to exhaust compressed working fluid at the outlet of the compressor assembly. The CAES system also includes a storage volume positioned downstream of the outlet of the compressor and configured to receive and store the compressed working fluid, a turbine assembly positioned downstream of the storage volume and configured to receive the compressed working fluid from the storage cavern at an inlet of the turbine assembly and exhaust expanded working fluid at an outlet of the turbine assembly, and a carbon dioxide separation unit positioned downstream of the outlet of the compressor assembly and upstream of the inlet of the turbine assembly, wherein the carbon dioxide separation unit is configured to remove a quantity of carbon dioxide from the compressed working fluid.
[0010] Various other features and advantages will be made apparent from the following detailed description and the drawings.
[0011] The drawings illustrate preferred embodiments presently contemplated for carrying out the invention.
[0013] FIG. 1 is a block diagram of an exemplary CAES system according to an embodiment of the invention.
[0014] FIG. 2 is a block diagram of an exemplary CAES system according to another embodiment of the invention.
[0016] Embodiments of the invention are described with respect to standard compressed air energy storage (CAES) systems and CAES systems having exhaust gas recirculation. However, it will be appreciated by those skilled in the art that embodiments of the invention are equally applicable for use with other air compression and expansion systems.
[0017] Referring to FIG. 1, a block diagram of an exemplary air compression and expansion system 100, such as, for example, a CAES system, is shown according to an embodiment of the invention. CAES system 100 includes a motor/generator unit 102, a first driving shaft 104 coupled to a compression system 106, and a second driving shaft 108 coupled to an expansion system 110. Clutches 112, 114 selectively disengage motor/generator unit 102 from compression system 106 and expansion system 110, respectively.
[0018] According to one embodiment, compression system 106 comprises a single compressor unit configured to receive a working fluid 116 at an inlet side 118 of compression system 106, compress working fluid 116 to a storage pressure (e.g., approximately 50-150 bar), and exhaust a compressed working fluid 120 at an outlet side 122 of compressor system 106. Alternatively, compression system 106 may include a number of compressor units coupled together in series. In this manner, the number of compressor units is configured to compress working fluid 116 from a first pressure to a second pressure in a number of pressure stages, with each of the compressor units configured to compress working fluid 116 to a pressure less than the difference between the first and second pressures. For example, the number of compressor units may be configured to compress working fluid 116 from an ambient pressure to a storage pressure. Likewise, according to one embodiment, expansion system 110 comprises one expander unit or turbine configured to expand a quantity of stored working fluid 124 from a third pressure to a fourth pressure. Alternatively, expansion system 110 may include a number of expander units coupled together in series and configured to operate in a number of pressure stages, with each of the expander units configured to expand stored working fluid 124 by a pressure less than a difference between the third pressure and the fourth pressure. Expansion system 110 is configured to receive the quantity of stored working fluid 124 at an inlet 126 of expansion system 110, expand the stored working fluid 124 to an exhaust pressure (e.g., approximately 1 bar), and exhaust an expanded working fluid 168 at an outlet 128 of expansion system 110.
[0019] Working fluid 116 enters CAES system 100 at inlet side 118 of compression system 106 and is compressed by compression system 106 as working fluid 116 travels through a compressor path 130. A compressed working fluid 120 exits outlet side 122 of compressor system 106 and travels along a first path 132 between compression system 106 and a compressed air storage volume 134, such as, for example, a natural cavern or salt cave. As it travels along first path 132, compressed working fluid 120 passes through an optional heat exchanger or aftercooler 136 (shown in phantom) to cool compressed working fluid 120 prior to storage and enters carbon dioxide (C02) separation system 138, wherein C02is filtered or separated from compressed working fluid 120. As shown in FIG. 1, C02separation system 138 is positioned within CAES system 100 downstream of compression system 106 and upstream of expansion system 110. C02separation system 138 includes a C02separation unit 140, such as, for example, a solvent-based C02capture unit or a membrane -based C02capture unit. C02separation system 138 also includes an optional treatment system 142, which may contain a trim cooler 144 (shown in phantom) to cool compressed working fluid 120 to a C02separation temperature and/or an optional pre-treatment device 146 (shown in phantom), which may be positioned upstream from C02separation unit 140 to remove particulates from working fluid 116. A C02-lean or C02-free working fluid 148 exits C02separation system 138 and is stored in compressed air storage volume 134. According to one embodiment, separated C02150 may be directed to an optional C02storage system 152 (shown in phantom).
[0020] Because working fluid 116 is compressed prior to passing through C02separation unit 140, the C02partial pressure of working fluid 116 is increased, thereby substantially increasing the driving force for C02separation. Also, because the volume of working fluid 116 passing through C02separation system 138 is reduced via compression, a smaller C02separation unit may be incorporated in CAES system 100, thereby reducing equipment costs.
[0021] A number of valves 154, 156, 158 are positioned between compression system 106, expansion system 110, and compressed air storage volume 134 to control movement of fluid throughout CAES system 100. For example, when valve 154 is closed, valves 156, 158 may be opened to direct a quantity of stored working fluid 124 along a second path 160 between compressed air storage volume 134 and expansion system 110. As it travels along second path 160, the quantity of stored working fluid 124 may pass though an optional combustor 162 (shown in phantom). Stored working fluid 124 enters at inlet 126 of expansion system 110 and is expanded by expansion system 110 as the stored working fluid 124 travels though an expansion path 164. Expanded working fluid 166 exits CAES system 100 at outlet 128 of expansion system 110.
[0022] Also, as shown in FIG. 1, according to one embodiment, C02separation system 138 is fluidly coupled along first path 132 between compression system 106 and compressed air storage volume 134 as described above. According to other embodiments, C02separation system 138 may be positioned at various alternative locations within CAES system 100, such as, for example, any of locations 168, 170, and 172 (shown in phantom). One skilled in the art will recognize that C02separation system 138 may be positioned at other locations as well, such as a position upstream of combustor 162 and downstream of expansion system 110, or at a position between valve 156 and compressed air storage volume 134, for example.
[0023] According to an embodiment of the invention, CAES system 100 may be optionally configured with a heat exchanger 174 (shown in phantom) to preheat the stored working fluid 124 before it is expanded in expansion system 110. In such an embodiment, all or a portion of expanded working fluid 166 is directed along path 176 such that it passes through heat exchanger 174.
[0024] In one embodiment, working fluid 116 is ambient air having a C02concentration of approximately 400 ppmv, for example. In such an embodiment, compression system 106 may be configured to compress working fluid 116 to a storage pressure of 100 bar, for example, such that compressed working fluid 120 has a C02partial pressure of approximately 0.04 bar at separation.
[0025] Alternatively, working fluid 116 may be flue gas exhausted from a power plant or industrial process, for example, having a percent volume of C02of approximately 3-30%. For example, working fluid 116 may be flue gas exhausted from a pulverized coal power plant having a C02concentration of approximately fifteen (15) percent volume. In this embodiment, compressed working fluid 120 may have a storage pressure of 100 bar and a corresponding C02partial pressure of approximately fifteen (15) bar at separation. As another example, working fluid 116 may be flue gas exhausted from a natural gas combined cycle having a C02concentration of approximately four (4) percent volume. In this embodiment, compressed working fluid 120 may be compressed to a storage pressure of 100 bar and have a C02partial pressure of approximately eight (8) bar at separation.
[0026] For CAES systems that include co-firing upstream of the expansion system (e.g., natural gas power plants), a portion of the exhausted expanded working fluid leaving the expansion system optionally may be recirculated back to the compressor, according to embodiments of the invention. For example, recirculated exhaust gas or recirculated fluid 178 (shown in phantom) comprising a fraction (e.g., up to 50%) of expanded working fluid 166 may be directed along a recirculation path 180 between outlet side 128 of expansion system 110 and inlet side 118 of compression system 106. Recirculated fluid 178 is mixed with working fluid 116 at inlet side 118 of compression system 106. As a result, the C02concentration in compressed working fluid 120 is increased, thereby increasing C02partial pressure and making C02separation easier. Working fluid 116 may enter compression system 106 in a smaller inlet stream in embodiments that incorporate recirculated exhaust fluid 178 than those embodiments that do not.
[0027] Referring now to FIG. 2, a block diagram of a CAES system 182 is shown according to an embodiment of the invention. CAES system 182 includes a motor 184 coupled to a compressor system 186, a storage cavern 188, a turbine system 190 coupled to a generator 192, and a C02separation system 194, such as, for example, C02separation system 152 (FIG. 1). CAES system 182 also includes a number of valves 196, 198, 200 that may be manipulated to control the movement of gas to and from storage cavern 188.
[0028] As shown in FIG. 2, compressor system 186 includes a first compressor 202 and a second compressor 204 with a gearbox 206 therebetween. First Turbine system 190 includes a first turbine 208 and a second turbine 210. Optional combustors 212, 214 (shown in phantom) may be positioned at locations at an inlet side inlet 216 of first turbine 208 and/or between first and second turbines 208, 210, as shown. Although only two compressors 202, 204 are shown in the present embodiment, it is contemplated that compression system 186 may include more than two compressors. Similarly, turbine system 190 may include more than two turbines.
[0029] Gas enters compressor system 186 at an inlet 218 of first compressor 202, travels through compression path 220, and exits compressor system 186 at an outlet 222 of second compressor 204. Gas is compressed to an intermediate pressure as it passes through first compressor 202, and is compressed to a final storage pressure as it passes through second compressor 204. An optional cooling unit 224 (shown in phantom) may be positioned between first and second compressors 202, 204 to pre-cool the gas prior to compression in second compressor 204.
[0030] After exiting compressor system 186, gas travels along a compressed gas path 226 formed between compressor system 186 and storage cavern 188. C02separation system 194 filters C02from the gas as the gas travels along compressed air path 226, in a similar manner as described with respect to C02separation system 138 of FIG. 1.
[0031] According to one embodiment, before the compressed gas is stored in cavern 188, it may pass through an optional cooling unit 228 (shown in phantom), which removes heat from the compressed air prior to storage in cavern 188. By removing heat from the compressed gas prior to storage, the integrity of cavern 188 may be protected. Although cooling unit 228 is shown upstream of C02separation system 194, alternatively, cooling unit 228 may be positioned downstream of C02separation system 194.
[0032] After being stored in cavern 188, compressed gas may travel along exit path 236 to turbine system 190. Alternatively, valves 196-200 may be manipulated to allow compressed gas to travel directly from compression system 186 to turbine system 190 without intermediate storage in cavern 188. Due to the configuration of turbine system 190, the compressed gas is allowed to expand as it passes therethrough, thereby causing rotation of turbine system 190. Gas is expanded to an intermediate expansion pressure as it passes through first turbine 208, and is further expanded to ambient pressure as it passes through second turbine 210. The rotation of turbine system 190 causes a drive shaft 230 connected to generator unit 192 to rotate, causing generator unit 192 to produce electricity.
[0033] According to one embodiment of the invention, CAES system 182 may optionally include a thermal energy storage (TES) unit 232 (shown in phantom). In such an embodiment, compressed gas passing along compressed air path 226 towards storage cavern 188 passes through TES unit 232, which removes heat from the compressed gas. The heat is stored by TES unit 232 and is later conveyed back to the compressed gas as the compressed gas passes back through TES unit 232 as the gas travels along an exit path 234 formed between storage cavern 188 and turbine system 190.
[0034] Although C02separation system 194 is shown in FIG. 2 at a position downstream of compressor system 186 and upstream of storage cavern 188, one skilled in the art will appreciate that C02separation system 194 may be positioned at any position downstream of first compressor 202 and upstream of second turbine 210. Thus, according to various embodiments, C02separation system 194 may be positioned at any of locations 236, 238, 240, 242 (shown in phantom), for example.
[0035] Therefore, in accordance with one embodiment, a gas compression and expansion system includes a compression system fluidly coupled to a storage compartment and configured to compress a first quantity of gas for storage in the storage compartment, the compression system including a compression path configured to convey the first quantity of gas therethrough. The gas compression and expansion system also includes an expansion system fluidly coupled to the storage compartment and configured to expand a second quantity of gas from the storage compartment, the expansion system including an expansion path configured to convey the second quantity of gas therethrough. Further, the gas compression and expansion system includes a first path fluidly coupled to the compression path and configured to convey the first quantity of gas to the storage compartment, a second path fluidly coupled to the expansion path and configured to convey the second quantity of gas from the storage compartment to the expansion system, and a carbon dioxide separation unit fluidly coupled to one of the first path, the second path, the compression path, and the expansion path, wherein the carbon dioxide separation unit is configured to remove a quantity of carbon dioxide from one of the first quantity of gas and the second quantity of gas.
[0036] In accordance with another embodiment, a method of manufacturing an air compression and expansion system includes configuring a compressor to compress an airstream for storage in a storage volume, coupling a first airflow path to the compressor and configuring the first airflow path to deliver a compressed airstream to the storage volume, and configuring a turbine to receive a quantity of the compressed airstream and expand the quantity of the compressed airstream. The method also includes coupling a second airflow path to the turbine and configuring the second airflow path to deliver the quantity of the compressed airstream to the turbine from the storage volume and coupling a carbon dioxide filter along at least one of the first airflow path and the second airflow path and configuring the carbon dioxide filter to filter a quantity of carbon dioxide from the compressed airstream.
[0037] In accordance with yet another embodiment, a compressed air energy storage (CAES) system includes a compressor assembly having an inlet and an outlet, the compressor configured to exhaust compressed working fluid at the outlet of the compressor assembly. The CAES system also includes a storage volume positioned downstream of the outlet of the compressor and configured to receive and store the compressed working fluid, a turbine assembly positioned downstream of the storage volume and configured to receive the compressed working fluid from the storage cavern at an inlet of the turbine assembly and exhaust expanded working fluid at an outlet of the turbine assembly, and a carbon dioxide separation unit positioned downstream of the outlet of the compressor assembly and upstream of the inlet of the turbine assembly, wherein the carbon dioxide separation unit is configured to remove a quantity of carbon dioxide from the compressed working fluid.
[0038] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

中文:
[0001]本发明的实施例大体涉及空气压缩和膨胀系统,并且更具体而言,涉及用于在空气压缩和膨胀系统中进行二氧化碳捕捉的系统和方法。
[0002]在许多行业中空气压缩和膨胀系统被用于多种应用。例如,在产生和存储能量方面,一个这种应用是将空气压缩和膨胀系统用作涡轮机。压缩空气能量存储(CAES)系统典型地包括具有一个或多个压缩机的压缩系,该一个或多个压缩机压缩进口空气,并且将压缩的进口空气提供给洞、地下存储器或其它压缩空气存储构件。然后在以后使用压缩空气来驱动一个或多个涡轮,以产生能量,诸如例如电能。在CAES系统的压缩级的运行期间,压缩的进口空气在存储之前典型地被冷却到洞的温度。在膨胀级的运行期间,空气从地下存储器中排出通过涡轮,并且膨胀,使得空气在环境压力下离开涡轮。
[0003]作为在高峰功率时间期间将能量注入电网中的源,CAES系统有效地帮助公用发电厂的功率发生的混合,同时在非高峰时间期间存储多余的能量。CAES系统还可使用从风力发动机中产生的能量来对压缩系提供动力,而压缩空气被输送到能量存储洞等。
[0004]虽然CAES系统可改进能量发生的效率,以及/或者在高峰时间期间对电网提供辅助能量,但是公用发电厂(例如煤发电厂和天然气发电厂)会产生大量二氧化碳(CO2),二氧化碳会增加大气温室气体。
[0005]因此,设计一种减少在公用发电厂中实现的CAES系统所产生的CO2的系统和方法将是合乎需要的。
[0006]本发明的实施例涉及用于在空气压缩和膨胀系统中进行二氧化碳捕捉的系统和方法。
[0007]因此,根据本发明的一方面,一种气体压缩和膨胀系统包括压缩系统,该压缩系统流体地联接到存储隔室上,并且构造成压缩用于存储在存储隔室中的第一量的气体,压缩系统包括构造成使第一量的气体传输通过其中的压缩路径。该气体压缩和膨胀系统还包括膨胀系统,该膨胀系统流体地联接到存储隔室上,并且构造成使来自存储隔室的第二量的气体膨胀,膨胀系统包括构造成使第二量的气体传输通过其中的膨胀路径。另外,该气体压缩和膨胀系统包括:第一路径,其流体地联接到压缩路径上,并且构造成将第一量的气体传输到存储隔室;第二路径,其流体地联接到膨胀路径上,并且构造成将第二量的气体从存储隔室传输到膨胀系统;以及流体地联接到第一路径、第二路径、压缩路径和膨胀路径中的一个上的二氧化碳分离单元,其中,二氧化碳分离单元构造成从第一量的气体和第二量的气体中的一个中移除一定量的二氧化碳。
[0008]根据本发明的另一方面,一种制造空气压缩和膨胀系统的方法包括:将压缩机构造成压缩用于存储在存储容积中的空气流;将第一空气流路径联接到压缩机上,并且将第一空气流路径构造成把压缩空气流输送到存储容积;以及将涡轮构造成接收一定量的压缩空气流,并且使该量的压缩空气流膨胀。该方法还包括将第二空气流路径联接到涡轮上,并且将第二空气流路径构造成把该量的压缩空气流从存储容积输送到涡轮;以及沿着第一空气流路径和第二空气流路径中的至少一个联接二氧化碳过滤器,并且将二氧化碳过滤器构造成从压缩空气流中过滤出一定量的二氧化碳。
[0009]根据本发明的另一方面,一种压缩空气能量存储(CAES)系统包括具有入口和出口的压缩机组件,压缩机构造成在压缩机组件的出口处排出压缩工作流体。CAES系统还包括:存储容积,其定位在压缩机的出口的下游,并且构造成接收和存储压缩工作流体;涡轮组件,其定位在存储容积的下游,并且构造成在涡轮组件的入口处接收来自存储洞的压缩工作流体,以及在涡轮组件的出口处排出膨胀工作流体;以及定位在压缩机组件的出口的下游和涡轮组件的入口的上游的二氧化碳分离单元,其中,二氧化碳分离单元构造成从压缩工作流体中移除一定量的二氧化碳。
[0010]根据以下详细描述和附图,将使得各种其它特征和优点是显而易见的。
[0011]图示出了在目前为了执行本发明而构想的优选实施例。
[0013]图1是根据本发明的一个实施例的示例性CAES系统的框图。
[0014]图2是根据本发明的另一个实施例的示例性CAES系统的框图。
[0016]关于标准压缩空气能量存储(CAES)系统和具有排气再循环的CAES系统来描述本发明的实施例。但是,本领域技术人员将理解,本发明的实施例同样能够应用来与其它空气压缩和膨胀系统一起使用。
[0017]参照图1,显示了根据本发明的一个实施例的示例性空气压缩和膨胀系统100(诸如例如CAES系统)的框图。CAES系统100包括马达/发电机单元102、联接到压缩系统106上的第一传动轴104,以及联接到膨胀系统110上的第二传动轴108。离合器112、114选择性地分别使马达/发电机单元102与压缩系统106和膨胀系统110脱开。
[0018]根据一个实施例,压缩系统106包括单个压缩机单元,该压缩机单元构造成在压缩系统106的入口侧118处接收工作流体116,将工作流体116压缩到存储压力(例如大约50巴-150巴),以及在压缩机系统106的出口侧122处排出压缩工作流体120。备选地,压缩系统106可包括许多串联地联接在一起的压缩机单元。照这样,该许多压缩机单元构造成以许多压力级将工作流体116从第一压力压缩到第二压力,各个压缩机单元构造成将工作流体116压缩小于第一压力和第二压力之间的差的压力。例如,该许多压缩机单元可构造成将工作流体116从环境压力压缩到存储压力。同样,根据一个实施例,膨胀系统110包括构造成使一定量的存储工作流体124从第三压力膨胀到第四压力的一个膨胀器单元或涡轮。备选地,膨胀系统110可包括串联地联接在一起且构造成以许多压力级运行的许多膨胀器单元,各个膨胀器单元构造成使存储工作流体124膨胀小于第三压力和第四压力之间的差的压力。膨胀系统110构造成在膨胀系统110的入口126处接收该量的存储工作流体124,使存储工作流体124膨胀到排出压力(例如大约1巴),以及在膨胀系统110的出口128处排出膨胀工作流体168。
[0019]工作流体116在压缩系统106的入口侧118处进入CAES系统100,并且在工作流体116行进通过压缩机路径130时,工作流体116被压缩系统106压缩。压缩工作流体120离开压缩机系统106的出口侧122,并且在压缩系统106和压缩空气存储容积134(诸如例如天然洞或盐洞)之间沿着第一路径132行进。在它沿着第一路径132行进时,压缩工作流体120传送通过用以在存储之前冷却压缩工作流体120的可选的热交换器或后冷却器136(以虚线显示),并且进入二氧化碳(CO2)分离系统138,在CO2分离系统138中,从压缩工作流体120中过滤或分离出CO2。如图1中显示的那样,CO2分离系统138在压缩系统106的下游和膨胀系统110的上游定位在CAES系统100内。CO2分离系统138包括CO2分离单元140,诸如例如基于溶剂的CO2捕捉单元或基于隔膜的CO2捕捉单元。CO2分离系统138还包括:可选的处理系统142,其可包含调温冷却器144(以虚线显示),以将压缩工作流体120冷却到CO2分离温度;以及/或者可选的预处理装置146(以虚线显示),其可定位在CO2分离单元140的上游,以从工作流体116中移除微粒。CO2稀薄或不含CO2的工作流体148离开CO2分离系统138,并且存储在压缩空气存储容积134中。根据一个实施例,分离出的CO2150可被引导到可选的CO2存储系统152(以虚线显示)。
[0020]因为工作流体116在传送通过CO2分离单元140之前被压缩,所以工作流体116的CO2分压增大,从而基本增大用于分离CO2的驱动力。而且,因为传送通过CO2分离系统138的工作流体116的容积由于压缩而减小,所以可在CAES系统100中结合较小的CO2分离单元,从而降低装备成本。
[0021]许多阀154、156、158定位在压缩系统106、膨胀系统110和压缩空气存储容积134之间,以控制流体在整个CAES系统100中的运动。例如,当阀154关闭时,可打开阀156、158,以在压缩空气存储容积134和膨胀系统110之间沿着第二路径160引导一定量的存储工作流体124。在它沿着第二路径160行进时,该量的存储工作流体124可传送通过可选的燃烧器162(以虚线显示)。存储工作流体124在膨胀系统110的入口126处进入,并且在存储工作流体124行进通过膨胀路径164时被膨胀系统110膨胀。膨胀工作流体166在膨胀系统110的出口128处离开CAES系统100。
[0022]而且,如图1中显示的那样,根据一个实施例,CO2分离系统138如上面描述的那样沿着第一路径132流体地联接在压缩系统106和压缩空气存储容积134之间。根据其它实施例,CO2分离系统138可定位在CAES系统100内的各种备选位置处,诸如例如位置168、170和172(以虚线显示)中的任一个。本领域技术人员将认可,CO2分离系统138也可定位在其它位置处,诸如例如在燃烧器162的上游和膨胀系统110的下游的位置处,或者在阀156和压缩空气存储容积134之间的位置处。
[0023]根据本发明的一个实施例,CAES系统100可以可选地构造有热交换器174(以虚线显示),以在存储工作流体124在膨胀系统110中膨胀之前预热它。在这种实施例中,沿着路径176引导膨胀工作流体166的全部或一部分,使其传送通过热交换器174。
[0024]在一个实施例中,工作流体116是例如具有大约400ppmv的CO2浓度的环境空气。在这种实施例中,压缩系统106可构造成将工作流体116压缩到例如100巴的存储压力,使得压缩工作流体120在分离时具有大约0.04巴的CO2分压。
[0025]备选地,工作流体116可为从发电厂或工业过程中排出的、例如具有大约3%-30%的体积百分比的CO2的烟道气。例如,工作流体116可为从粉煤发电厂中排出的、具有大约百分之十五(15)(体积)的CO2浓度的烟道气。在这个实施例中,压缩工作流体120可具有100巴的存储压力,并且在分离时具有大约十五(15)巴的对应的CO2分压。作为另一个实例,工作流体116可为从天然气联合循环中排出的、具有大约百分之四(4)(体积)的CO2浓度的烟道气。在这个实施例中,压缩工作流体120可被压缩到100巴的存储压力,并且在分离时具有大约八(8)巴的CO2分压。
[0026]对于在膨胀系统的上游包括共燃的CAES系统(例如天然气发电厂),根据本发明的实施例,离开膨胀系统的排出的膨胀工作流体的一部分可以可选地再循环回到压缩机。例如,可在膨胀系统110的出口侧128和压缩系统106的入口侧118之间沿着再循环路径180引导包括一部分(例如高达50%)的膨胀工作流体166的再循环排气或再循环流体178(以虚线显示)。再循环流体178在压缩系统106的入口侧118处与工作流体116混合。因此,压缩工作流体120中的CO2浓度增大,从而增大CO2分压,以及使CO2分离更容易。与没有结合再循环排出流体178的那些实施例相比,在结合了再循环排出流体178的实施例中,工作流体116可以更小的入口流进入压缩系统106。
[0027]现在参照图2,显示了根据本发明的一个实施例的CAES系统182的框图。CAES系统182包括联接到压缩机系统186上的马达184、存储洞188、联接到发电机192上的涡轮系统190,以及CO2分离系统194,诸如例如CO2分离系统152(图1)。CAES系统182还包括许多可被操纵来控制气体通往和离开存储洞188的运动的阀196、198、200。
[0028]如图2中显示的那样,压缩机系统186包括在它们之间具有齿轮箱206的第一压缩机202和第二压缩机204。第一涡轮系统190包括第一涡轮208和第二涡轮210。可选的燃烧器212、214(以虚线显示)如所显示的那样可定位在第一涡轮208的入口侧入口216处和/或在第一涡轮208和第二涡轮210之间的位置处。虽然在本实施例中显示了仅两个压缩机202、204,但是构想了压缩系统186可包括不止两个压缩机。类似地,涡轮系统190可包括不止两个涡轮。
[0029]气体在第一压缩机202的入口218处进入压缩机系统186,行进通过压缩路径220,并且在第二压缩机204的出口222处离开压缩机系统186。在气体传送通过第一压缩机202时,气体被压缩到中间压力,以及在气体传送通过第二压缩机204时,气体被压缩到最终存储压力。可选的冷却单元224(以虚线显示)可定位在第一压缩机202和第二压缩机204之间,以在气体在第二压缩机204中被压缩之前预先冷却它。
[0030]在离开压缩机系统186之后,气体沿着在压缩机系统186和存储洞188之间形成的压缩气体路径226行进。在气体沿着压缩空气路径226行进时,CO2分离系统194以类似于关于图1的CO2分离系统138所描述的方式从气体中过滤出CO2。
[0031]根据一个实施例,在压缩气体存储在洞188中之前,压缩气体可传送通过可选的冷却单元228(以虚线显示),在压缩空气存储在洞188中之前,冷却单元228从压缩空气中移除热。通过在存储之前从压缩气体中移除热,可保护洞188的完整性。虽然显示了冷却单元228在CO2分离系统194的上游,但是,备选地,冷却单元228可定位在CO2分离系统194的下游。
[0032]在存储在洞188中之后,压缩气体可沿着离开路径236行进到涡轮系统190。备选地,可操纵阀196-200,以允许压缩气体直接从压缩系统186行进到涡轮系统190,而不需要在洞188中进行中间存储。由于涡轮系统190的构造的原因,允许压缩气体在它传送通过涡轮系统190时膨胀,从而导致涡轮系统190旋转。气体在其传送通过第一涡轮208时膨胀到中间膨胀压力,并且在其传送通过第二涡轮210时进一步膨胀到环境压力。涡轮系统190的旋转会导致连接到发电机单元192上的传动轴230旋转,从而导致发电机单元192发电。
[0033]根据本发明的一个实施例,CAES系统182可以可选地包括热能存储(TES)单元232(以虚线显示)。在这种实施例中,沿着压缩空气路径226传送向存储洞188的压缩气体传送通过TES单元232,TES单元232从压缩气体中移除热。热由TES单元232存储,并且随后在压缩气体通过TES单元232而传送回时,随着气体沿着形成于存储洞188和涡轮系统190之间的离开路径234行进,热被传输回到压缩气体。
[0034]虽然在图2中显示了CO2分离系统194在压缩机系统186的下游和存储洞188的上游的位置处,但是本领域技术人员将理解,CO2分离系统194可定位在第一压缩机202的下游和第二涡轮210的上游的任何位置处。因而,根据各种实施例,CO2分离系统194可定位在例如位置236、238、240、242(以虚线显示)中的任一个处。
[0035]因此,根据一个实施例,一种气体压缩和膨胀系统包括压缩系统,该压缩系统流体地联接到存储隔室上,并且构造成压缩用于存储在存储隔室中的第一量的气体,压缩系统包括构造成将第一量的气体传输通过其中的压缩路径。气体压缩和膨胀系统还包括膨胀系统,该膨胀系统流体地联接到存储隔室上,并且构造成使来自存储隔室的第二量的气体膨胀,膨胀系统包括构造成将第二量的气体传输通过其中的膨胀路径。另外,气体压缩和膨胀系统包括:第一路径,其流体地联接到压缩路径上,并且构造成将第一量的气体传输到存储隔室;第二路径,其流体地联接到膨胀路径上,并且构造成将第二量的气体从存储隔室传输到膨胀系统;以及流体地联接到第一路径、第二路径、压缩路径和膨胀路径中的一个上的二氧化碳分离单元,其中,二氧化碳分离单元构造成从第一量的气体和第二量的气体中的一个中移除一定量的二氧化碳。
[0036]根据另一个实施例,一种制造空气压缩和膨胀系统的方法包括:将压缩机构造成压缩用于存储在存储容积中的空气流;将第一空气流路径联接到压缩机上,并且将第一空气流路径构造成把压缩空气流输送到存储容积;以及将涡轮构造成接收一定量的压缩空气流,并且使该量的压缩空气流膨胀。该方法还包括将第二空气流路径联接到涡轮上,并且将第二空气流路径构造成把该量的压缩空气流从存储容积输送到涡轮;以及沿着第一空气流路径和第二空气流路径中的至少一个联接二氧化碳过滤器,并且将二氧化碳过滤器构造成从压缩空气流中过滤出一定量的二氧化碳。
[0037]根据又一个实施例,一种压缩空气能量存储(CAES)系统包括具有入口和出口的压缩机组件,压缩机构造成在压缩机组件的出口处排出压缩工作流体。CAES系统还包括:存储容积,其定位在压缩机的出口的下游,并且构造成接收和存储压缩工作流体;涡轮组件,其定位在存储容积的下游,并且构造成在涡轮组件的入口处接收来自存储洞的压缩工作流体,以及在涡轮组件的出口处排出膨胀工作流体;以及定位在压缩机组件的出口的下游和涡轮组件的入口的上游的二氧化碳分离单元,其中,二氧化碳分离单元构造成从压缩工作流体中移除一定量的二氧化碳。
[0038]本书面描述使用实例来公开本发明,包括最佳模式,并且还使本领域任何技术人员能够实践本发明,包括制造和使用任何装置或系统,以及执行任何结合的方法。本发明的可授予专利的范围由权利要求限定,并且可包括本领域技术人员想到的其它实例。如果这样的其它实例具有不异于权利要求的字面语言的结构元素,或者如果这样的其它实例包括与权利要求的字面语言无实质性差异的等效结构元素,则它们意图处于权利要求的范围之内。