The invention is directed to a fluid distributing apparatus and to its use in a process to obtain a compressed gas.
Compressing gas is a well known process. Typically compressors are used to compress a gas. Gas compression is for example part of a gas turbine process to generate power. US-A-2011/0088404 describes a process wherein air is compressed in a gas compressor. The compressed air is combusted with a fuel and the resulting hot process gas is expanded in an expander. The expander is coupled to a device to convert the rotational energy to power, e.g. electrical power. The energy required to operate the compressor is typically delivered by the rotational energy of the expander by a direct coupling of the compressor and the expander as shown in
BE1016500 describes a process wherein air is compressed in several compression stages. The compressed air is used in a combustion turbine. Before being compressed the air is heated using heat recovery from the exhaust gas of the turbine.
US2011/036097 describes a rotary regenerative heat exchanger for heat exchange between a compressed gas and the exhaust gas of a combustor.
A disadvantage of a traditional gas turbine process as illustrated above is that a large compressor is required. A further disadvantage is that the energy to operate the compressor is provided by the rotational energy of the expanders of the gas turbine. Thus part of the energy obtained in the expanders is used for compressing the combustion air. This coupled system makes the gas turbine process expensive and less efficient. It is an object of the present invention to provide an alternative process for compressing a gas.
GB712107 describes a pressure exchanger comprising a cell rotor in which gas is compressed and expanded.
U.S. Pat. No. 4,614,204 describes a multiport rotary disc valve.
U.S. Pat. No. 6,487,843 described a compressor type machine in which air is enclosed in air chambers present between interlocking rotating blades as present on two screw spindles. The air is heated isochorically against exhaust gasses flowing counter-currently through the hollow blades.
Applicants have now found a process to obtain a compressed gas which uses a novel fluid distributor apparatus.
This invention is directed to a fluid distributing apparatus comprising a fixed part and
Applicants have found that this apparatus may advantageously be used in a process to obtain a compressed gas. The invention is therefore also directed to a configuration comprising the fluid distributing apparatus, a process using this configuration to obtain a compressed gas and a process to generate electrical power using the process to obtain a compressed gas as will be described in more detail below.
In the apparatus according to the present invention the fixed part is provided with at least one inlet channel and at least one outlet channel. Preferably the fixed part is provided with at least two inlet channels and at least one outlet channels or with at least one inlet channel and at least two outlet channels. In this manner it is possible to combine two or more fluids or to split a fluid. In another embodiment the fixed part is provided with at least two inlet channels and at least two outlet channels. Preferably the number of inlet channels and outlet channels in the fixed part is equal. This enables one to direct each flow of fluid supplied to the inlet channel of the fixed part into a different outlet channel at a time. By rotation of the rotating part the outlet channels connected to the inlet channels continuously change. This is particularly advantageous in a configuration described below.
The rotating part is rotatably positioned relative to the fixed part such that the rotating part can have multiple rotational positions relative to the fixed part. Suitably the rotating part can rotate continuously in one direction around its axis of rotation. Positioning of the rotating part relative to the fixed part is suitably achieved such that fluid exiting the channels of the fixed part and entering the channels of the rotating part do not or almost not enter the space between the rotating part and the fixed part. This can be achieved by minimising the distance between fixed and rotating part to such a distance wherein rotation remains possible. Optionally the facing surfaces of the fixed and rotating part may be provided with a film or liquid to reduce friction and enable rotation.
The rotating part is provided with at least a connecting channel having an inlet and outlet opening in the rotating part. The number of connecting channels will relate to the number of inlet and outlet channels in the fixed part and to the possible combinations between inlet and outlet channels. For example when the number of inlet and outlet channels is 2 it may be advantageous to have 4 connecting channels.
The inlet and outlet opening of at least one connecting channel in the rotating part aligns with the facing openings of at least one inlet and outlet channel in the fixed part in at least one rotational position. With align is here meant that a flow of fluid is possible from the inlet channel in the fixed pat to the inlet opening of the connecting channel in the rotating part and/or a flow is possible from the outlet opening of the connecting channel to the inlet opening of the outlet channel.
In at least one other rotational position the inlet and outlet opening of the connecting channel in the rotating part are not aligned with the same facing openings of the inlet and outlet channel in the fixed part. By not aligned is here meant that no flow of fluid is possible via the inlet channel, the connecting channel and the outlet channel.
Preferably the fixed part is provided with m inlet channels and m outlet channels and wherein each inlet and outlet channel has a facing opening facing the rotating part, wherein the rotating part is provided with m2 connecting channels, each connecting channel having an inlet and outlet opening in the rotating part, wherein the inlet opening of at least one connecting channel in the rotating part aligns with the facing opening of one inlet channel in the fixed part and wherein the outlet opening of the connecting channel aligns with the facing opening of an outlet channel in at least one rotational position and wherein in at least one other rotational position the same inlet opening of the connecting channel in the rotating part is aligned with a facing opening of a different inlet channel and aligned with a facing opening of a different outlet channel. m is 2 or more, suitably 4 or more. The maximum value for m will depend on the ability in the rotating member to accommodate for the resulting high number of connecting channels.
The rotating part may have a cylindrical shape. The fixed part or fixed parts are positioned axial relative to the rotating part at one side or at both sides as illustrated in
One can imagine that the design of the rotating part as illustrated in
The above is illustrated by
In
The tubular rotating part 232 illustrated in
Suitably the rotating part is mechanically connected to an external driving means for achieving the rotational movement when in use. Examples of suitable driving means are electrically driven motors, hydraulically driven motors and fuel combustion driven motors.
The fluid distributing apparatus according to the invention may be used to distribute any type of fluid. Examples of fluids which may be used as the feed are liquid fluids, gaseous fluids, evaporating liquids, condensing gasses, their mixtures and the foregoing in admixture with solids. Applications for this distributor may for example be in analytical chemistry and separation technology. In analytical chemistry the apparatus may be used to split a stream exiting a gas chromatograph.
Applicants found that the apparatus may be advantageously be used to connect a number of vessels and more preferably be used in a process described below. Preferably the fixed part or parts are provided with an inlet channel to receive a feed gas, one or more inlet channels to receive gas having varying pressures, an inlet channel to receive pressurised gas and an outlet channel to discharge the feed gas, one or more outlet channels to discharge gas having varying pressures and an outlet channel to discharge gas to a heat exchanger and wherein the rotating part is provided with connecting channels to, at one rotational position, connect
The channels in the rotating part may be configured such that when starting from a starting position and rotating the rotating part to a next rotational position each inlet channel in the fixed part is fluidly connected to a different outlet channel in the fixed part for part of the rotation or for a full rotation.
The apparatus may connect one or more configurations of 2n+4 or more vessels, wherein n is 2 or more, each vessel having an inlet and an outlet connected to the fixed part of the apparatus. Suitably the apparatus further connects, one vessel with the inlet of a heat exchanger, one vessel with the outlet of the heat exchanger, one vessel with the inlet channel to receive a feed gas and one vessel with an inlet to supply a purging gas and an outlet to discharge the purging gas. The index n may be from 2 and up to 500 and suitably n is at least 4. The number of vessels connected by one apparatus may range up to 1000. The invention is also directed to a system comprising an apparatus as here described and a heat exchanger.
The invention is directed to the following process. Process to obtain a continuous flow of compressed gas starting from a feed gas having a lower pressure by performing the following steps:
State 1 is a filling state,
State 2 to State (n+1) is a state wherein the content of the vessel increases in pressure by levelling,
State (n+2) is a state wherein the content of the vessel is provided to a heat exchanger,
State (n+3) is a low pressure outlet state wherein the vessel receives the content the heat,
State (n+4) to State (2n+3) are states wherein a part of the content of the vessel in State (n+4) to State (2n+3) is used to level with the vessels in State 2 to Sate (n+1) as in step (iii) of the process according to the invention, and
State (2n+4) wherein the remaining driving gas is discharged from the vessel,
and wherein a fluid distributor apparatus according to the invention is used to continuously change the state of each vessel to a next state and provide the required gas transport between the vessels, to receive the feed gas and to discharge and receive gas to and from the heat exchanger such that steps (i)-(iii) are continuously repeated and a continuous flow of compressed gas is obtained.
When the vessels change from state the vessels which were in state (n+2) and state (n+3) will be temporarily disconnected from the heat exchanger. In this time period a gas having a high temperature and pressure will develop in the enclosed heat exchanger and can be discharged as the product gas.
The above process is advantageous because a compressed gas can be obtained starting from a feed gas making use of the energy contained in the fluid having a higher temperature. This source of energy is different from the rotational energy required to operate a compressor, which is either electrically powered or coupled to an expander as in US-A-2011/0088404. Fluids having an elevated temperature for use in step (i) may be exhaust gasses from other processes, exhaust gas from a melting furnaces, gas turbine, gas or diesel engines, incinerators or combinations of said fluids either used in admixture or sequential. A possible fluid may be a flue gas, optionally partially, generated by on-purpose combustion of a fuel. Possible fuels are hydrogen, synthesis gas or solid, fluid or gaseous carbonaceous fuels, for example natural gas, refinery off-gas, a biomass solid, fluid or gas fuel, a domestic waste fuel, crude oil derived fuel, e.g. kerosene, diesel fuel or bunker fuel. Suitably a mixture comprising an exhaust gas from another process and the combustion gasses generated by this on-purpose combustion of a fuel is used as the fluid having the elevated temperature in step (i). Alternatively the fluid having an elevated temperature may also be a liquid, for example a hydrocarbon, water or their mixtures as obtained from sub-surface formations and having an elevated geo-thermal temperature.
The feed gas is preferably an oxygen comprising gas for use as feed component of a combustor as part of a gas turbine. In this preferred embodiment part of the fluid having a higher temperature is comprised of the exhaust gas of the expander of the gas turbine.
The temperature of the feed gas is suitably as low as possible, preferably below 50° C. and even more preferably below 20° C. Low temperature is advantageous because it increases the capacity of a given apparatus in which the above process can be performed. The pressure of the feed gas may be between 0.1 and 0.6 MPa. If the feed gas is an oxygen comprising gas for use as feed component of a combustor as part of a gas turbine it is preferred that the feed gas has a pressure of between 0.11 and 0.6 MPa, preferably obtained in a compressor.
The gas having an intermediate pressure as used in step (i) may have a pressure of between 0.2 and 5 MPa or between 0.2 and 3 MPa. In step (i) the pressure and temperature of a gas having an intermediate pressure is increased by means of indirect heat exchange against the fluid having a higher temperature to obtain a gas high in pressure and temperature. This indirect heat exchange may be performed by processes well known to the skilled person. Preferably the gas having an intermediate pressure is kept within an enclosed space for a certain period of time wherein the heat exchange is performed such to more optimally increase both temperature and pressure in step (i). The temperature of the fluid may be between 100 and 1000° C., suitably between 175 and 850° C. and preferably between 250 and 400° C.
In step (ii) part of the gas high in temperature and pressure is obtained as the compressed gas. The pressure of the compressed gas is suitably between 0.14 and 5 MPa or between 0.14 and 3 MPa. The temperature is suitably between 50 and 550° C. The pressure increase may be between 0.04 and 5 Mpa or between 0.04 and 2.5 MPa. By increasing the number of levelling stages it is possible to achieve higher increases in pressure.
In step (iii) another part of the gas high in temperature and pressure is used as a driving gas to increase the pressure of the starting gas in one or more stages to obtain the gas having an intermediate pressure for use in step (i). With the term ‘driving gas’ is here meant a gas having a higher pressure which is mixed with a gas having a lower pressure. With the term ‘using as driving gas’ is meant that the driving gas is added to another gas having a lower pressure resulting in a mixed gas composition having a pressure between the pressure of the driving gas and the pressure of the other gas. Preferably the pressure of the starting gas is increased in step (iii) in n levelling stages, wherein n is 2 or more. In this process part of the driving gas is added to the gas obtained in the (n−1)th levelling stage to increase the pressure of said gas in the nth levelling stage to obtain the gas having an intermediate pressure. Part of the remaining driving gas is added to the gas obtained in the (n−2)th levelling stage in the (n−1)th levelling stage. This sequence of adding part of the remaining driving gas to the gas obtained in the previous stage is continued for the remaining (n−2) levelling stages and adding the then remaining driving gas to the starting gas in the 1st levelling stage. If in the above process driving gas remain after performing this 1st levelling stage it is suitably discharged.
State (n+4) to State (2n+3) are states wherein a part of the content of the vessel in State (n+4) to State (2n+3) is used to level with the vessels in State 2 to State (n+1). Because levelling suitably is performed making use of the pressure difference a vessel in State (n+4) will level with the vessel in State (n+1), the vessel in State (n=5) will level with the vessel in State (n), wherein this is repeated until the vessel in State (2n+3) levels with the vessel in State (2).
The number n is suitably from 2 to and including 50 and preferably from 4 to and including 20.
Preferably steps (i)-(iii) are continuously repeated to obtain a continuous flow of compressed gas. Preferably one cycle of steps (i)-(iii) is performed between 1 and 2000 times per minute.
The above process is illustrated by
The fluid distributing apparatus according to the invention is capable of continuously connecting the connecting conduits 13, 14, 16, 17, 18, 20, 21, 22 and 23 to different vessels as illustrated in
Each vessel 211, 205, 212 and 206 has an inlet and an outlet conduit connected to distributer 24 by means of lines 211a, 211b, 205a, 205b, 212a, 212b, 206a and 206b respectively. The fixed part of distributer 24 is provided with an inlet to receive a feed gas as supplied via line 103 and an outlet to discharge a compressed gas via line 108. The fixed part of distributor 24 has an inlet and outlet connected to an outlet and inlet of a heat exchanger 107 via lines 106 and 105 respectively. The fixed part of distributor 24 has an outlet to discharge a remaining driving gas via line 109 and an inlet to supply a purging gas via line 124.
The distributor 24 has a rotating part 26 and two fixed parts 27, 28 at its two opposite ends along the axis. The rotating part 26 is suitably a cylindrical part. The rotating part 26 is provided with connecting channels 29. The rotating part 26 is rotationally moveable relative to the two fixed parts. Preferably the rotating part 26 rotates within a housing (not shown). The, preferably tubular, housing connects the first and second fixed parts 27 and 28. The first and second fixed parts 27, 28 are provided with inlet and outlet channels 30, 31 connected to the inlet and outlet conduits at one end and to connecting channels 29 at their other ends. In this manner the inlet channels 30 of fixed part 27 communicate with the outlet channels 30 of the same fixed part 27 via the connecting channels 29 present in the rotating part 26 at a certain rotational position of the rotating part 26 relative to the fixed part 27.
In
The fluid distributor 24 of
The vessels and distributor illustrated in
In
In
The invention is thus also directed to an apparatus according wherein the connecting channels in the rotating part 300 are elongated vessels 401-412 positioned parallel with respect to each other and in a circle around its axis of rotation 304, each vessel provided with a two openings its opposite ends and wherein at one rotational position
a fixed part 301 is provided with an channel 307 to provide a feed gas to one of the vessels 401,
a fixed part 301 or 302 is provided with a connecting channel 420, 421, 422, 423 connecting the opening of a first vessel 402, 403, 404, 405 with the opening a second vessel 411, 410, 409, 408 respectively,
the fixed part 301 or 302 is provided with a channel 308 to discharge gas from a vessel 406 to for example a heat exchanger and a channel in the opposite fixed part to provide gas to this vessel 406,
the fixed part or parts 301 or 302 is provided with a channel 309 to provide gas from for example this heat exchanger to a vessel 407 and with a channel in the opposite fixed part to discharge gas from this vessel 407,
the fixed part 301 or 302 is provided with a channel 306 to receive a purge gas to one vessel 412 and an outlet channel 312 in the opposite fixed part to discharge the purged gas from this vessel 412.
Preferably the above apparatus comprises one or more configurations of 2n+4 or more vessels, wherein n is the number of channels 420, 421, 422, 423 and is 2 or more and wherein the connecting channels 420, 421, 422, 423 provide pressure levelling between n pairs of vessels, such as first vessels 402, 403, 404, 405 with the with second vessels 411, 410, 409, 408 of
The fixed part may be composed of two cylindrical shaped parts and wherein the fixed parts are positioned axial relative to the rotating part at one side or at both sides as illustrated in
The embodiments of
the rotating part is rotatably positioned relative to the fixed part such that the rotating part can have multiple rotational positions relative to the fixed part, wherein the rotating part is provided with 2n+4 elongated vessels, or sets of 2n+4 elongated vessels, having a larger cross-sectional area than the cross-sectional area of the inlet and outlet channels present in the fixed parts and wherein the vessels have an inlet and outlet opening at their opposite ends and wherein the elongated vessels run parallel with the axis of rotation and positioned along the circumference of a circle,
the fixed part is provided with an channel to provide a feed gas to one the vessels,
the fixed part is provided with n connecting channels, each connecting channel fluidly connecting the opening of an elongated vessel with the opening of another elongated vessel,
the fixed part is provided with a channel to discharge gas from an elongated vessel to a heat exchanger and provided with a channel to provide gas to this vessel,
the fixed part is provided with a channel to provide gas from the heat exchanger to a vessel and provided with a channel to discharge gas from this vessel,
the fixed part is provided with a channel to receive a purge gas to one vessel and provided with an outlet channel to discharge the purged gas from this vessel, and
wherein the inlet and outlet opening of at least one elongated vessel in the rotating part aligns with the facing openings of at least one inlet and outlet channel in the fixed part in at least one rotational position and wherein in at least one other rotational position the inlet and outlet opening of the elongated vessel in the rotating part is not aligned with the same facing openings of the inlet and outlet channel in the fixed part.
The single fixed part referred to above may be comprised of two parts as in
The invention is also directed to a process to generate electrical power by means of a gas turbine, wherein said gas turbine uses a fuel and compressed oxygen comprising gas as feed and wherein the following steps are performed,
Preferably a stream of expanded flue gas is obtained in step (d) and wherein this flue gas is used to increase the temperature of the compressed oxygen gas by means of indirect heat exchange prior to performing step (c).
Preferably step (b) is performed by compressing said oxygen containing gas by means of a process according to the present invention, and wherein the remaining driving gas is combined with the flue gas after being reduced in temperature by means of the heat exchange and wherein the resulting combined gas flow is used as the fluid having a higher temperature in step (i). Preferably the combined gas flow is increased in caloric value prior to be used as the fluid having a higher temperature in step (i) by mixing said combined gas flow with an exhaust gas of another process or by combusting an additional fuel. The additional fuel may be any gaseous, liquid or solid fuel, such as for example natural gas, synthesis gas, hydrogen, refinery off-gas, a biomass solid, such as wood, a domestic waste fuel and crude oil derived fuel, e.g. kerosene, diesel fuel or bunker fuel.
The fuel used in step (c) may suitably be the same as the above examples described for the additional fuel. Suitably the fuel used in step (c) is a gaseous or liquid fuel, such as for example natural gas, synthesis gas, hydrogen, refinery off-gas, and crude oil derived fuel, e.g. kerosene, diesel fuel or bunker fuel. Even more preferably the fuel is a gaseous fuel, suitably natural gas, synthesis gas, hydrogen and/or refinery off-gas.
The synthesis gas described above may be obtained by gasification of coal or residual fractions derived from a crude oil. The hydrogen may be obtained by subjecting synthesis gas, such as obtained by these gasification processes, to a water-gas shift reaction.
The compressor used in step (a) may be directly coupled to the expander of the gas turbine used in step (d) or preferably connected via a gear box to the expander. This is advantageous when the fluid having a higher temperature as used in the process comprises heated gasses obtained from another process. The compressor may also be driven independently from the gas turbine, for example an electrically driven compressor may be used. The mass flow of such, for example exhaust, gasses may vary and thus the capacity to increase the pressure and temperature may vary. By being able to control the compressor independently from the expander such variations can be compensated for in an easier manner.
The above process will be illustrated by
The gas 108 is further increased in temperature in heat exchanger 110 to obtain a heated gas 111. The compressed and heated oxygen in heated gas 111 is used to combust a fuel 113 in a combustor 112 to obtain a pressurised combustion gas 114. The pressurised combustion gas 114 is expanded in expander 115 to generate power, e.g. electricity by operating a generator 116. The stream of expanded flue gas 117 thus obtained has a high temperature level. The expanded flue gas 117 is used to increase the temperature of the gas 108 by indirect heat exchange in heat exchanger 110 thereby obtaining heated gas 111 and a stream of exhaust gas 118 having a lower temperature than expanded flue gas 117. In
The process to obtain a compressed gas and its application in a process to generate electrical energy according to the invention may find application in air separation processes, classical energy producing industry, domestic energy production, energy and heat co-generation processes, automotive and marine, for example automotive or marine hybrid engine applications, power generation from high energy streams as present in chemical and refinery processes, for example steam cracking processes, delayed coking processes and gasification processes, cement process, carbon black reactors, iron reduction process, steel soaking pits, incinerators, dryers, aluminium dry hearth melting processes, copper scrap remelt furnaces, aluminium scrap remelt processes, after burner processes, regenerative thermal oxidizers and in power generation applications where a steam cycle is not desired, such as for example in off-shore applications.
Number | Date | Country | Kind |
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2011310 | Aug 2013 | NL | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NL2014/050512 | 7/25/2014 | WO | 00 |