EP2473715A2

EP2473715A2 - Method and apparatus for generating power especially from biomass or biomass-based sources of energy

Info

Publication number: EP2473715A2
Application number: EP10759804A
Authority: EP
Inventors: Franz Wimmer
Original assignee: Conpower Energieanlagen GmbH and Co KG
Current assignee: Conpower Energieanlagen GmbH and Co KG
Priority date: 2009-09-04
Filing date: 2010-09-03
Publication date: 2012-07-11
Also published as: WO2011026633A2; WO2011026633A3; DE102009040300A1

Abstract

Disclosed are a method and an apparatus for generating power especially from biomass or biomass-based sources of energy, according to the preamble of claims 1 and 9. In order to be able to increase the overall efficiency in the energy balance of an entire power generation apparatus, the method is an INTEGRATED two-stage power generation method in which two different working media are used in two thermally coupled, but otherwise independent thermodynamic cycles, an expansion machine or a first turbine that is connected to a first electric generator is operated using the first working medium in a high-temperature cycle (HT) in the first stage, and the waste heat is subsequently converted into electricity especially by cooling the high-temperature cycle in a second cycle operated as a low-temperature cycle (NT).

Description

Method and device for generating energy, in particular from biomass or biomass energy carriers

Method and device for power generation

in particular from biomass or biomass energy carriers, according to the preamble of patent claims 1 and 9.

In the direct combustion of biomass or biomass energy sources such as biogas or biofuels, heat energy is generated from renewable raw materials, which can be converted into electricity. Because the

Primary energy sources in this case except for their

Production process are C0 ₂ -neutral, this also applies to the electricity produced from it.

In particular, because of the said C0 _{2 consideration} , it is particularly important just such energy or

Power generation processes in efficiency always too

optimize.

Thus, it is known to nachverströmen waste heat from any energy processes even in the case of accumulating waste heat with ORC processes, as is known from DE 10 2006 043 518 AI.

The name ORC means "organic-rankine-eyele".

By this is meant processes which include a turbine or a work machine with an organic, light weight drive steaming working medium instead of steam.

RC, on the other hand, only means Rankine-Cycle, where the same thermodynamic cycle is performed here, but not with an organic working medium.

The possibility of general waste heat conversion can thus be carried out with the aid of low-temperature ORC method. The operating temperatures for

Evaporation of an organic medium are below 100 ° C.

Thus, such low-temperature ORC plants can be connected to a waste heat source, which in this

Temperature range provide waste heat.

In this case, however, further heat losses must be avoided in the coupling of such an ORC device.

The invention is therefore based on the object to further develop a method and a device of the generic type such that overall a greater ^* overall efficiency arises in the balance of an entire power generation facility.

The object is in a method of the generic type according to the invention by the

characterizing features of claim 1 solved.

Further advantageous embodiments of the method are specified in the dependent claims 2 to 8. With regard to a device of the generic type, the object is achieved by the features of claim 9. Further advantageous embodiments of the device or the system are specified in the remaining dependent claims.

Core of the inventive method is that the

Procedure an INTEGRATED 2-stage

Energy generation method is in which in two thermally coupled but otherwise independent thermodynamic cycle see two different working media are used, and in said first stage in a high-temperature circuit (HT) a relaxation machine or a first turbine is operated with the first working medium with a first electricity generating generator is connected, and that the waste heat in particular by cooling / condensation in

High-temperature cycle in a second, as

Low-temperature circuit (NT) working cycle process is nachverstromt.

It is essential that two thermodynamically coupled, but otherwise independent processes

be integrated, where two independent

Working media are used. In the simplest case, this is water vapor on one side, operated as a high-temperature side, and an ORC working medium of a known type on the other, as a low-temperature side

operated side.

On the high-temperature side of the working medium is directly a relaxation machine, such as a steam piston machine, or a turbine flows mechanically provided with a generator or coupled, which generates electricity from the movement. This concerns the so-called high-temperature side. The high temperature side may be a high temperature ORC cycle, or one

Steam cycle. In a subsequent process, the waste heat generated in the high-temperature circuit, essentially at the condenser, is used for the thermal feed of an evaporator of a low-temperature ORC circuit. Thus, in two stages, both the

High-temperature heat as well as the otherwise declining low-temperature heat flows, but different working media are used.

This results according to the invention in the result so a

INTEGRATED 2-stage power generation process. The difference is the direct coupling of the usable waste heat of the first power generation stage.

Intergated method ultimately means corporeal, so also according to the Struturellen features of the device features further described below, that the

Integration can go so far that, for example, the cooler or the first (high-temperature)

Energy production facility or process none

known cooler as such are more, but

integrated evaporator for a secondary circuit on

Low temperature. That the cooling of a

Combustion engine etc does not take place over

Air cooling. In the case of the invention, the coolers are DIRECTLY replaced by evaporators. This INTEGRATIVE solution is significantly more energy efficient in the downstream use of waste heat. Advantageously, it is stated that the

High-temperature circuit may also be an ORC cycle, which is operated at a temperature of more than 100 ° C. Such work, i. Evaporator media for high temperature ORC plants are known and available for temperatures as high as 350 ° C. For higher temperatures, water / steam is more suitable.

Alternatively, it is provided that the high-temperature circuit is a steam cycle with a

Piston engine is. This is suitable

To drive evaporator temperatures up to 500 ° C, for example, on the model of known classic steam engines.

In a further advantageous embodiment, it is provided that the low-temperature ORC cycle, i. the

Evaporator medium thereof is supplied with heat energy, at a temperature level of less than 100 ° C. This is due to waste heat at the condenser and / or at the cooling interfaces of the high temperature circuit. The integrative process does not carry out any conventional coolers but rather the coolers and / or

Capacitors are not connected to conventional heat exchangers for feeding the Niedetempertaurkreislaufes, but the radiator and / or capacitors of the

High temperature range are designed directly as a heat exchanger or evaporator of the low temperature range.

In a further advantageous embodiment, it is stated that the low-temperature residual or waste heat of the

Low-temperature ORC cycle of approx. 20 ° C

is cooled exclusively in air.

Alternatively, however, can also be a three-stage Heat is used by the low-temperature residual heat is used either directly or after introduction into a heat reservoir through the use of a heat pump below as heating heat.

This leads to a further increase in the

Economics .

It is particularly advantageous that the

Residual heat directly into the ground, or in the

Groundwater aquifer of the soil is fed, and immediately or at a later date this stored there low-temperature residual heat is used by a heat pump and geothermal or geothermal probes, and is used to operate a building heating or preheating the ORC cycle.

This residual heat is not "destroyed" but rather stored as heat storage by the discharge into the soil, where it can be retrieved at a later time and brought to a usable temperature level by means of a heat pump

Heat pump achieved heat can optionally as

Preheating the ORC process, and / or used for direct heating bspw a building.

Core of the device according to the invention is that the device a first working media circuit as a high-temperature circuit and another

Niedertemperaturkreislauf as ORC cycle has that burned in the high-temperature cycle in particular biomass as a renewable resource and the

Combustion heat is converted into electrical energy, and that the condenser and / or cooler of the

High-temperature circuit directly as an evaporator of the ORC Circuit is operable.

In a further advantageous embodiment, it is stated that the high-temperature circuit is a high-temperature ORC circuit which can be operated at a temperature of more than 100 ° C. with a corresponding high-temperature ORC working medium. This

High temperature range is known to be operable with organic working fluids up to 350 ° C.

It may alternatively be advantageously provided that the high-temperature circuit is a steam cycle. This particular in the event that

Evaporator temperatures of about 500 ° C can be achieved.

For the high temperature range, steam engines can be used, so that in the high-temperature circuit a

Piston engine converts the energy of the working medium.

Alternatively, it can also be provided that in

High-temperature circuit a turbine converts the energy of the working medium.

For the subordinate stage of the low-temperature range, it is provided that the working medium is operated at a temperature of less than 100 ° C. in the low-temperature ORC cycle.

The structurally integrative arrangement and coupling of the

High temperature range with the low temperature range increases the efficiency enormously, because the

Heat coupling between high temperature (HT) and low temperature (NT) no longer via a coupling of HT condenser with heat exchanger with NT evaporator takes place, but instead the HT condenser is also the NT evaporator. Furthermore, it is configured that the qua conversion into electrical energy no longer usable low-temperature residual or waste heat of the low-temperature ORC cycle of about 20 ° C by means of a luftumströmten cooler

is dissipated.

Alternatively, but also a third

Heat utilization level can be perceived by

the low-temperature residual heat either directly or after introduction into a heat reservoir eg via ground probes the aquifer can be fed, and there by the

Use of a heat pump retrievable and as

thermally raised heat is available again.

So this is fed into a naturally existing reservoir. The temperature level raised there is then used energetically by a connected heat pump to generate heat.

The invention is illustrated in the drawing and explained in more detail below.

It shows :

Figure 1: Overview of the integration of high temperature and low temperature circuit

FIG. 2: exemplary embodiment with heat reservoir

FIG. 1 shows a clear representation of the division into high-temperature circulation _. , (HT) 1 and Low temperature circuit (NT) 2. Im

High-temperature cycle is achieved by combustion of particular biomass energy sources such as pellets, dusty biomass and / or biogas, a temperature of up to 1000 ° C in the combustion chamber. The

Pressure medium of the high-temperature circuit 1 is vaporized at a temperature up to about 500 ° C. The

Transfer of the heat of combustion at 1,000 ° C to the working or pressure medium at only 500 ° C includes the enthalpy of vaporization. Working fluid temperatures of well over 500 ° C are thermodynamic

Reasons impractical. Working medium for this high-temperature cycle is in this high

Temperature range water vapor. The high-temperature circuit 1 shown only schematically consists of a known manner, from the evaporator

Heat of combustion is heated, a turbine-generator arrangement or a work machine-generator arrangement. Included in the circuit is also a condenser, or a heat exchanger combined therewith, which decouples this waste heat from the high-temperature circuit 1 into a second low-temperature circuit 2, i. in a local

Feed evaporator. This low-temperature circuit 2 also contains the said evaporator, as well as a

Turbine Generator Arrangement or Work Machine Generator Arrangement.

In an advantageous but not compulsory manner, the condenser of the high-temperature circuit 1 is structurally in the evaporator of the low-temperature circuit second

integrated to ensure the most effective transmission of low-temperature waste heat. In said low-temperature circuit 2, the working medium is advantageously organic ORC working medium used. This can typically be used between about 70 ° C to 350 ° C.

The said integrated condenser / evaporator unit between the two circuits 1 and 2 is

Condensator side flows through the first working medium (water vapor) and the evaporator side of the second

Working medium flows through ORC working medium. Thus, this is called integrated construction of

Condenser / evaporator in the invention

two-stage generation process of electrical energy a kind of heat exchanger between two circuits or cycles 1 and 2. This is thermally insulated to the outside. The special feature here is that these combined or integrated condenser / evaporator unit are flowed through by two different working media. High temperature side, this can be steam or

Be high-temperature ORC medium, and second-rate

Low temperature ORC medium.

The residual heat generated in the low-temperature circuit at the condenser, i. on a cooler 4, however, is cooled to a quasi-infinite heat reservoir, and this at a temperature level of about 20 ° C. These

Residual heat is virtually no longer verstrombar at this temperature level.

Figure 2, however, shows a special

Exemplary embodiment in which the residual heat of the radiator 4 or the condenser

Low-temperature circuit 2 is supplied at the temperature level of about 20 ° C a heat storage, where, for example raised by a heat pump, the temperature level and, for example, can serve for heat supply in a building.

For this purpose, the cooler 4 may have a thermal transition to a heat storage in the form of the aquifer. This accumulating waste heat would be fed into the soil, and in an existing heat pump 5 back to a usable heating technology

Temperature level to be raised. The representation of Figure 1 generated from the two

Circuits electrical energy. As shown in FIG. 2, directly usable heating heat is generated in addition to electrical energy.

szeichen

1 high-temperature process (HT), first Arbeitsmedi

2 low temperature process (NT), second

working medium

3 generating electrical energy from heat

4 coolers

5 heat pump

Claims

claims

1. Method in which by combustion,

especially heat generated by biomass as a renewable raw material is converted into electrical energy,

characterized,

that the process is an INTEGRATED 2-stage power generation process in which two different working media are used in two thermally coupled but otherwise independent thermodynamic cycles, and in said first stage in a high temperature (HT) cycle

Relaxation machine or a first turbine is operated with the first working medium, which with a first electricity generating generator

is connected, and that the waste heat is in particular by cooling the high-temperature circuit in a second, operating as a low-temperature circuit (NT) circulating process.

2. The method according to claim 1,

characterized,

that the cooling or condensation in the HT circuit and the evaporation in the NT circuit combined in a common

Condenser / evaporator unit is made. Method according to claim 1 or 2,

characterized,

that the high-temperature circuit is also an ORC cycle, which is operated at a temperature of more than 100 ° C.

Method according to claim 1 or 2,

characterized in that the high temperature circuit is a steam cycle with a steam piston machine.

Method according to claim 3 or 4,

characterized,

that the low-temperature ORC cycle at a temperature of less than 100 ° C.

is operated.

Method according to claim 3, 4 or 5,

characterized,

that the low-temperature residual or waste heat of the low-temperature ORC cycle of about 20 ° C in air is cooled exclusively in air.

A method according to claim 3, 4 or ^5:

characterized,

that the low-temperature residual heat either directly, or after initiation into a

Heat reservoir through the use of a

Heat pump is used as heating heat. Method according to claim 7,

characterized,

that the residual heat is fed directly into the soil, or into the groundwater aquifer, and immediately or at a later date

Time these stored there

Low-temperature residual heat by means of a

Heat pump is used with ground collectors or ground probes, and to operate a

Building heating or preheating the ORC circuit is used.

Device for generating electrical

Energy from combustion, especially at

Combustion of biomass or energy sources from biomass,

characterized,

that the device has a first working medium circuit as a high-temperature circuit and a further low-temperature circuit as an ORC circuit, and that in both thermally coupled, but otherwise independent

Circular processes have different working media.

10. Device according to claim 9,

characterized,

that burned in the high-temperature circuit (1) in particular biomass as a renewable resource and the heat of combustion is converted into electrical energy, and that the condenser and / or cooler of the high-temperature circuit (1) is designed directly as a heat exchanger, via which the evaporator of

Low-temperature ORC circuit (2) is directly operable.

11. Device according to claim 9 or 10,

characterized,

that the high-temperature circuit a

High-temperature ORC cycle, which at a temperature of more than 100 ° C with a

corresponding high-temperature ORC working medium is operable.

12. Device according to claim 9 or 10,

characterized,

that the high-temperature circuit a

"Steam cycle.

13. Device according to one of claims 9 to 12, characterized

that in the high-temperature circuit a

Piston engine the energy of the

Implemented working medium.

14. Device according to one of claims 9 to 12, characterized

that in the high-temperature circuit, a turbine converts the energy of the working medium.

15. Device according to one of the preceding

Claims ,

characterized,

that in the low-temperature O C cycle, the working medium is operated at a temperature of less than 100 ° C.

16. Device according to one of the preceding

claims

characterized,

that the low-temperature residual or waste heat of the low-temperature ORC cycle of about 20 ° C is removed by means of a luftumströmten cooler.

17. Device according to one of the preceding

Claims ,

characterized,

^' that the low-temperature residual heat ¹ either directly, or after initiation into a

Warmer reservoir eg via geothermal probes

Groundwater is supplied, and there by the use of a heat pump again retrievable and as thermally raised heat is available again.