DE202012104774U1 - Device and biomass power plant - Google Patents

Abstract

Device (50) having a load resistor (52) for low-loss power control of a biomass power plant (10), wherein the load resistor (52) for varying an electrical power (34) of a power generator (24) of the biomass power plant (10) to be fed into a supply network (32). by means of a receiver, in particular by means of a ripple control receiver (58), remotely controllable, characterized in that the device (50) has at least one heat exchanger (54).

Description

The invention initially relates to a device with a load resistor for low-loss power control of a biomass power plant, wherein the load resistance for varying a fed into a supply network electrical power of a power generator of the biomass power plant by means of a receiver, in particular by means of a ripple control receiver, remotely controllable. Furthermore, the invention relates to a biomass power plant.

In addition to hydropower, wind power and photovoltaic systems, biomass power plants are increasingly being used for regenerative power generation. In this type of power plant biomass is decomposed in a bioreactor by complex biological-chemical processes with the release of biogas. The liberated biogas can, for example, be converted into electricity in a suitable power generator and / or converted into heat in thermal consumption points. One of the current challenges is the high power fluctuations naturally occurring in the context of regenerative power generation, in particular by means of photovoltaics and wind turbines. These unavoidable and sometimes difficult to predict power fluctuations are caused, for example, by weak-wind periods and times of low incidence of light. In the existing electrical grids such strong fluctuating electrical power can not be fed easily, as this could lead to overloads and concomitant power outages. Consequently, the power output of at least part of the regenerative power plants must be regulated in order to ensure at all times a balance between the electrical power fed into the grid and the electrical power requested by the connected consumers.

Particularly in the case of biomass power plants, the electric power provided can be regulated only with difficulty, if at all, because the complex chemical-biological processes taking place in the bioreactor have a high temporal latency, which is a short-term adaptation of the amount of biogas released by the biogas reactor and thus a variation make the electrical power generated by the biomass power tool virtually impossible. A technical possibility would be a compression and caching of the currently non-catalysis biogas in suitable pressure vessels, which is not useful due to the high energy and design effort.

From the DE 20 2012 001 459 U1 is a device for generating at least electrical energy from biomass, in particular a combined heat and power plant, known. In order to be able to adjust the feed-in power of the current grid situation, the grid connection of the generator is coupled to a device for adapting the feed-in power. This device has to adapt the feed-in power at least one load device for converting the branched stream into heat and is preferably constructed with a variable load resistor, which is equipped with a ripple control receiver that can receive signals from a network operator and evaluate. With the help of the ripple control receiver, the load resistance can be controlled remotely by the network operator in such a way that the electrical power consumed by the latter and converted into heat can be equalized almost instantaneously to a current network situation. If, for example, there is a supply of excess power in the supply network, the thermal power loss of the load resistor can be increased remotely, so that less electrical power is fed into the supply network. If, on the other hand, there is a lack of electricity in the supply network due to a high demand of the consumers, then the power loss of the load resistance may be. be shut down to zero, so that the maximum possible electrical power of the biogas-powered generator is fed into the grid. This mechanism for controlling the electrical power output by the generator comes without an immediate effect on the amount of biogas released by the biogas reactor and / or an energy-intensive intermediate storage of biogas and also without moving parts subject to wear. The disadvantage is, inter alia, that the converted in ohmic load resistance into heat and not fed into the supply network power component is no longer energetically usable or is lost as waste heat irrevocably.

The invention is after all the problem of specifying a device for the most energy-efficient adaptation of the electrical power of a biomass power plant to a current network state of a public utility network.

The invention solves this problem with a device of the type mentioned, wherein the device has at least one heat exchanger. The fact that the device has at least one heat exchanger, if necessary, at least a portion of the electrical power output from the generator can be converted by the ohmic load resistance into heat, which can be used on the heat exchanger but again for the biomass power plant, in particular for heating the biogas reactor. As a result of this active heating of the biogas reactor increases the biological activity, which leads to an increase in the gas yield. The load resistance may have a thermal power loss of several hundred kilowatts, depending on the electrical power of the generator and an electrical power to be absorbed, if necessary, from a grid for grid stabilization.

Preferably, by means of the receiver control signals of a network operator can be received, based on which a thermal power loss of the load resistance is adjustable. In this way, the electrical feed-in power of the power generator can be automated according to the specifications of a network operator regardless of the biogas production in the biogas reactor or adjusted from the outside. Preferably, the power loss of the load resistor is adjustable in stages, so that an electrical feed power remains, which corresponds for example to 100%, 70%, 40% (or 30%) or 0% of a maximum electric power of the power generator.

Advantageously, the heat energy of a hot air flow emitted by the load resistance can be supplied by means of the at least one heat exchanger to a thermal point of consumption, in particular a biogas reactor of the biomass power station. This achieves an at least partially energetic recovery of the heat loss arising in the load resistor. Preferably, cold ambient air flows through the load resistor and is heated in this case. The hot or hot air stream preferably passes through an (air-water) heat exchanger in which water is circulated and heated. The hot water flow is heated directly via a simple pipeline or indirectly via a e.g. snake-shaped heat exchanger, the biomass in the bioreactor.

In an advantageous development, at least one actuator, in particular at least one flap, is provided for dividing the hot air flow between the heat exchanger and the environment. As a result, between 0% and 100% of the hot or warm air flow emitted by the load resistance can be routed via the heat exchanger and thus to the thermal delivery point or discharged into the environment. Preferably, the flap allows a continuous distribution of the hot air flow.

Preferably, a modem, in particular a GPRS modem, is provided for the bidirectional exchange of control signals with a virtual power plant in order in particular to set the thermal power loss of the load resistor. As a result, control signals of a virtual power plant can be used for the suitable adjustment of the thermal power loss of the load resistor. Instead of a GPRS modem, radio modems employing a higher data transmission rate, e.g. UMTS modems or LTE modems. The term "virtual power plant" in the context of the present specification defines an imaginary power plant constructed with a plurality of interconnected, but independent, distributed small and micro-power plants. Such a virtual power plant can have a total capacity of up to several 1,000 megawatts and can contain up to 300,000 micro-power plants.

In the case of an advantageous embodiment, at least one measuring point is provided for detecting physical quantities. Thereby, a multiplicity of different measured values, such as e.g. Temperatures, pressures, mechanical forces, rotational speeds, humidity values, dew points, conductivities, electrical currents and voltages, recorded and e.g. be zugleitet by means of suitable sensors of a digital control and / or regulating device. In the control and / or regulating device, which is preferably constructed with a digital computer unit, the evaluation and the further processing of the measured values supplied by the sensor take place.

Advantageously, by means of at least one measuring point, the electrical power currently fed into the connected supply network by the power generator and / or the electrical power absorbed therefrom can be determined. This makes it possible to measure the current electrical power fed into the supply network or, if appropriate, the electrical power absorbed therefrom, and, if necessary, to produce an energy balance of the biomass power plant as part of the virtual power plant.

In an advantageous development, in particular a temperature θ in the biogas reactor of the biomass power plant can be determined by means of at least one measuring point. As a result, the temperature evolution within the biogas reactor can be detected and e.g. the thermal power loss of the load resistance can be correspondingly increased or decreased, in particular to avoid overcooling or overheating of the biomass.

In an advantageous development, the actuator can be controlled in particular in dependence on the temperature θ in the biogas reactor. As a result, the overheating of the biogas reactor and the collapse of the gas generation can be prevented by the heat loss occurring in the load resistance is at least partially dissipated into the environment when exceeding a predetermined temperature limit for the chemical-biological processes in the biogas reactor.

Advantageously, depending on the control signals of the virtual power plant, the electric power fed in by the power generator or the electrical power absorbed by the power grid can be adjusted. As a result, the biomass power plant in the case of a power failure "positive" electrical power fed into the grid and in the case of Stromüberangebots but also "negative" electrical power from this record. To achieve this purpose, the load resistor has a permissible thermal power loss, which corresponds approximately to the maximum electrical power of the power generator plus a possibly from the supply network optionally dissipated, negative electric power. The sign of the electrical power is in each case dependent on the direction of the power or energy flow.

In an advantageous embodiment, the control signals of the network operator received by the receiver have priority over the control signals of the virtual power plant. As a result, an electrical overload due to a power supply in a coexisting power surplus in the supply network and thus the risk of power outages are largely excluded.

In addition, the object specified above is achieved by a biomass power plant in which, in particular, the device according to at least one of claims 1 to 11 is used for low-loss electrical power control. As a result, the waste heat arising as a result of power adjustment of the biomass power plant to the current supply network situation in ohmic load resistance can be recovered at least partially energetically by the waste heat is used by the heat exchanger for heating the biomass contained in the biogas reactor.

Further advantageous embodiments will become apparent from the dependent claims and from the closer explained with reference to the drawings embodiments. In the drawing show:

1 a schematic diagram of a biomass power plant with a device according to the invention;

2 a plan view of the device;

3 a view of an air inlet of the device of 2 ; and

4 a side view of the device of 2 ,

1 shows a schematic diagram of a biomass power plant with a device according to the invention. A biomass power plant 10 includes, among other things, a silo-shaped biogas reactor 12 that at least partially with a biomass 14 is filled. Inside the biogas reactor 12 Biogas produced by chemical-biological processes 16 gets over the line 18 up to a drive unit 20 in which the implementation of the biogas 16 stored chemical energy is converted into mechanical rotational energy. By means of the drive unit 20 , which may be, for example, a gas-powered piston engine, a gas turbine or the like, is an electric generator 22 driven. The drive unit 20 puts together with the generator 22 the electric power generator 24 of the biomass power plant 10 In the generated biogas 16 it is primarily methane (CH ₄ ) or other readily combustible gases.

The electric generator 22 delivered electrical power 26 passes via electrical cables, not shown, to a measuring point 28 and from there to a transfer point 30 a supply network 32 , In the area of the transfer point 30 Preferably, the usually indispensable adaptation of the voltage level of the generator takes place 22 to the in the supply network 32 prevailing higher voltage, which is generally done by an indicated transformer.

Using the measuring point 28 can be removed from the electric generator 24 currently in the supply network 32 fed electrical power 34 and one possibly from the supply network 32 absorbed (negative) electrical power 36 at any time and with high accuracy. The electric generator 22 delivered electrical power 26 as well as behind the measuring point 28 pending electrical power 34 are apart from any, by the power measurement within the measuring point 28 conditional losses, essentially identical, as long as no electrical power is diverted.

To the stability and thus the security of supply of the public electrical supply network 32 In its entirety, and in particular to ensure a balance at all times between the demand for electricity and the current power generation of all feeding power plants, a grid operator couples 38 unidirectional control signals 40 into the supply network 32 one, by everyone, in the supply network 32 feed-in power plant selectively evaluated and used for power control. The unidirectional control signals 40 essentially encode information about the current operating state of the electrical supply network 32 and run exclusively by the network operator 38 in the direction of Ripple control receiver 48 , Each ripple control receiver of a power plant has an individual code, allowing selective control of the connected and in the utility grid 32 feed-in power plants by the grid operator 38 is feasible. A feedback of information in the reverse direction by means of the control signals 40 is not scheduled.

The device according to the invention 50 for low-loss control of the biomass power plant 10 includes, inter alia, a substantially resistive load resistance 52 , an (air-water) heat exchanger 54 , a control and / or regulating device 56 , a ripple control receiver 58 for reception and decoding of the network operator 38 into the supply network 32 coupled control signals 40 , wherein their evaluation preferably by means of the control and / or regulating device 56 he follows. Furthermore, it is preferably a GPRS modem 60 or another modem based on an alternative radio communication technology. Using the GPRS modem 60 can be bidirectional control signals 62 wireless with a virtual power plant 64 change. The concept of the virtual power plant 64 defined in the context of this description, the interaction of a variety of each self-sufficient small and micro-power plants, which together in the supply network 32 and can communicate with each other wirelessly and / or wirelessly and in their entirety represent an almost instantaneous imaginable (large) power plant with an electrical output of up to some 1,000 MW. It is also important that the unidirectional control signals 40 of the network operator 38 unconditional priority over the bidirectional control signals of the virtual power plant 64 have to under any circumstances the security of supply of the public electrical supply network 32 to ensure.

In full load operation of the biomass power plant 10 is the power generator 22 provided electrical power 26 . 34 - apart from minor losses within the measuring point 28 - completely in the electrical supply network 32 fed. This situation arises in the case of a high electricity demand in the supply network 32 the desired normal operating state of the biomass power plant 10 represents.

In the electrical supply network 32 However, a power supply excess, it is based on the ripple control receiver 58 received control signals 40 the in the supply network 32 fed electrical power 34 by connecting the load resistor 52 reduced accordingly. This is an electrical power 66 eg in the area of the measuring point 28 branched off and the load resistance 52 fed. By varying the ohmic power loss of the load resistance 52 - Preferably in stages and controlled by the control and / or regulating device 58 in particular depending on the control signals 40 of the network operator 38 done - can the in the area of the measuring point 28 branched off electrical power 66 be set so high that either 100%, 70%, 40% (30%) or 0% of the maximum possible electrical power 26 . 34 of the power generator 24 into the supply network 32 be fed. The control and regulating device 58 is for this purpose by means of a line 67 with the measuring point 28 connected. About the line 67 may be the control and / or regulating device 56 at the same time the amount within the measuring point 28 determined electrical services 26 . 34 . 36 be supplied.

The excess, ie in the supply network 32 currently not required, electrical power 66 will be in the load resistance 52 converted into heat energy and in the form of a warm air stream 68 issued. This hot air stream 68 enters via a 1 exemplary as a flat flap 70 trained actuator wholly or partly to the heat exchanger 54 in which water is preferred as a coolant in a water cycle 72 is circulated and heated. The heated water of the water cycle 72 gives its heat energy via another heat exchanger 74 into the biomass 14 in the biogas reactor 12 from. Instead of water, the water cycle can 72 also be filled with a different coolant.

The heat exchanger 74 is in the 1 exemplified with a simple, straight running pipeline. Deviating from this, the heat exchanger 74 also be formed with at least one example, serpentine, meandering or helically bent pipe. In addition, the heat exchanger can 74 further constructive measures to increase the effective heat transfer area between the water cycle 72 and the biomass 14 , such as ribs, plates or the like for surface enlargement connected to the pipeline. Instead of biomass 14 in the bioreactor 12 as preferred thermal consumption or acceptance point for in the load resistance 52 accumulating heat loss can, with a not too large spatial distance alternatively or additionally, other heat consumers, such as housing heaters or heaters for commercial enterprises using the water cycle 72 be supplied with heat. It is also important that the heat exchanger 74 over a sufficient long-term stability against the usually chemically aggressive biomass 14 features.

Through the heat exchanger 74 is in a partial load operation of the biomass power plant 10 the biomass 14 by means of in the load resistance 52 warmed up lost heat loss and thus the Release of biogas 12 stimulated in the long term, resulting in the load resistance 52 released waste heat is fed to a meaningful energetic use.

A (rotary) angular position of the flap 70 is by means of a servomotor 76 controlled by the control and / or regulating device 56 - As indicated by the dashed line arrow - in each case depending on the current operating state of the device 50 and the biomass power plant 12 preferably infinitely pivotable. In the in 1 Illustrated and horizontal position of the flap shown by a solid line 70 becomes the hot air flow 68 completely through the heat exchanger 54 directed, resulting in maximum heating of the biomass 14 in the biogas reactor 12 established. With at least one additional measuring point 78 detects the control and / or regulating device 56 in addition, the temperature θ of the biomass 14 , Exceeds the measured temperature of the biomass 14 a preset, maximum permissible limit, then the flap 70 pivoted from the direction indicated by the solid line, horizontal position in the direction indicated by a dotted line, diagonal 45 ° position, whereby the hot air flow 68 almost completely into the environment 80 the device 50 is derived and no further heating of the biomass 14 in the biogas reactor 12 he follows. In the load resistance 52 occurring heat loss in the form of hot air flow 68 under all operating conditions of the device 50 To be able to discharge reliably is at least one, in 1 not shown, possibly multi-stage fan provided.

In the event of a supply of electricity in the supply network 32 It can - in addition to a reduction in the fed-in electrical power 34 of the power generator 24 down to zero - even electric power may be required 36 from the supply network 32 actively deduct. In such a constellation, the excess electrical power 66 sometimes. plus at least part of the electrical power 26 of the power generator 24 controlled by the control and / or regulating device 56 - taking into account the of the virtual power plant 64 emitted, bidirectional control signals 62 - from the supply network 32 subtracted and the load resistance 52 fed. In order to achieve this purpose, a permissible thermal power loss of the resistive load resistor must be ensured 52 be so high that this is the maximum possible electrical power of the generator 22 plus one if necessary. from the electrical supply network 32 maximum dissipated, excess electrical power 36 - Including a security surcharge - can reliably absorb and convert into heat. In these complex and by the control and / or regulating device 56 controlled regulatory processes have signals 40 of the network operator 38 basically unrestricted priority over the control signals 62 of the virtual power plant 64 when there are logical contradictions between the control signals 40 and the control signals 62 should come.

As a result, the device allows 50 with the help of the load resistance 52 a comparatively fast responding regulation of the generator 24 into the supply network 32 delivered electrical power 34 for timely adaptation to different states of the supply network 32 , wherein the inevitably occurring heat loss in an energetically advantageous manner by means of the heat exchanger 54 in the biogas reactor 12 is returned and therefore remains usable. In contrast, a direct regulation of the electrical power of the generator 24 , For example, by an immediate variation of the amount of biogas produced due to the enormous inertia of the chemical-biological process of biogas release and the lack of suitable factors on the biomass 14 not practicable.

The 2 shows a plan view of the device according to the invention. The device 50 comprises a substantially cuboid, channel-like housing 90 with an air intake 92 by means of a blower 94 cold ambient air 96 from the environment 80 sucked and by the load resistance 52 is guided through. The sucked in ambient air 96 gets from the load resistance 52 Heavily heated and hits as hot air stream 68 to a - deviating from the embodiment in accordance with the 1 - as a sector-shaped flap 98 trained actuator. The flap 98 is a vertical axis perpendicular to the plane of the drawing 100 at an angle 102 formed pivotable around. The sector-shaped flap 98 includes two quarter-circle holding plates 104 . 106 on the vertical axis 100 are mounted parallel, congruent and spaced from each other. At the two not designated, quarter-circular arches of the retaining plates 104 . 106 is a trough-shaped cylinder jacket section 108 for deflecting the warm air flow 68 educated.

In the in 2 shown with a solid black line position of the flap 98 flows through the hot air flow 68 this largely unhindered and reaches the heat exchanger 54 with the connected water cycle 72 , The in the heat exchanger 54 cooled hot air flow 68 passes through an air outlet 110 of the housing 90 in the nearby areas 80 the device 50 where the air outlet 110 opposite to the air inlet 92 on the housing 90 is arranged. In the direction indicated by a dashed line, at an angle 102 pivoted about 90 ° counterclockwise position of the flap 98 covered this the heat exchanger 54 completely, so that the warm air flow 68 not through the heat exchanger 54 occurs, but via a lateral air outlet 112 in the nearby areas 80 escapes. Laterally on the housing 90 are also the control and / or regulating device 56 , the ripple control receiver 58 as well as the GPRS modem 60 arranged.

The 3 illustrates a simplified view of the air inlet 92 of the housing 90 the device 50 , The air intake 92 is with a total of eight parallel and evenly spaced spaced air baffles 114 covered. Below the baffles 114 is the air intake 92 with a tight mesh 116 provided, the non-designated openings each having an oval geometry. The oval openings are each arranged in horizontally extending rows, wherein the rows are vertically one above the other and here each offset horizontally positioned. The housing 90 the device 50 stands on at least four feet, of which only two feet 118 are visible.

The 4 shows a schematic side view of the housing 90 the device 50 with the air intake 92 and the opposite to this air outlet 110 ,

About the air intake 92 gets the cold ambient air 96 into the device 50 and over the air outlet 110 leaves the cooled down hot air stream 68 the device back into the environment 80 , The baffles 114 are each at an angle α of about 30 ° relative to the horizontal stream of hot air 68 inclined formed and end each have a drip edge - of which only one representative of all the rest of the reference numeral 120 contributes - in particular the penetration of driving rain and foreign bodies in the device 50 to avoid.

All mentioned in the above description of the figures, in the claims and in the introduction of the description features can be used individually as well as in any combination with each other. The disclosure of the invention is therefore not limited to the described or claimed feature combinations. Rather, all feature combinations are to be regarded as disclosed.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202012001459 U1 [0004]

Claims (12)

Contraption ( 50 ) with a load resistor ( 52 ) for the low-loss power control of a biomass power plant ( 10 ), wherein the load resistance ( 52 ) for varying one in a supply network ( 32 ) to be fed electrical power ( 34 ) of a generator ( 24 ) of the biomass power plant ( 10 ) by means of a receiver, in particular by means of a ripple control receiver ( 58 ), remotely controllable, characterized in that the device ( 50 ) at least one heat exchanger ( 54 ) having. Contraption ( 50 ) according to claim 1, characterized in that by means of the receiver control signals ( 40 ) of a network operator ( 38 ) are receivable, based on which a thermal power loss of the load resistance ( 52 ) is adjustable. Contraption ( 50 ) according to claim 1 or 2, characterized in that the thermal energy of one of the load resistor ( 52 ) discharged hot air stream ( 68 ) by means of the at least one heat exchanger ( 54 ) a thermal consumption point, in particular a biogas reactor ( 12 ) of the biomass power plant ( 10 ), can be fed. Contraption ( 50 ) according to one of claims 1 to 3, characterized in that at least one actuator, in particular at least one flap ( 70 . 98 ), for the division of the warm air flow ( 68 ) between the heat exchanger ( 54 ) and the environment ( 80 ) is provided. Contraption ( 50 ) according to one of claims 1 to 4, characterized in that a modem, in particular a GPRS modem ( 60 ), for bidirectional exchange of control signals ( 62 ) with a virtual power plant ( 64 ) is provided, in particular the thermal power loss of the load resistance ( 52 ). Contraption ( 50 ) according to one of claims 1 to 5, characterized in that at least one measuring point is provided for detecting physical quantities. Contraption ( 50 ) according to claim 6, characterized in that by means of at least one measuring point ( 28 ) generated by the generator ( 24 ) into the connected supply network ( 32 ) currently fed electrical power ( 34 ) and / or the electrical power consumed therefrom ( 36 ) can be determined. Contraption ( 50 ) according to claim 6, characterized in that by means of at least one measuring point ( 78 ), in particular a temperature θ in the biogas reactor ( 12 ) of the biomass power plant ( 10 ) can be determined. Contraption ( 50 ) according to claim 8, characterized in that the actuator in particular in dependence on the temperature θ in the biogas reactor ( 12 ) is controllable. Contraption ( 50 ) according to one of claims 1 to 9, characterized in that in dependence of the control signals ( 62 ) of the virtual power plant ( 64 ) generated by the generator ( 24 ) fed electrical power ( 34 ) or from the supply network ( 32 ) recorded electrical power ( 36 ) is adjustable. Contraption ( 50 ) according to any one of claims 1 to 10, characterized in that the control signals received by the receiver ( 40 ) of the network operator ( 38 ) Priority before the control signals ( 62 ) of the virtual power plant ( 64 ) to have. Biomass power plant ( 10 ), characterized in that for low-loss electrical power control of the biomass power plant ( 10 ), in particular the device ( 50 ) according to at least one of claims 1 to 11 is used.

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