METHOD FOR CONTROLLED OPERATION OF A BIOTECHNOLOGICAL APPARATUS AND BIOREACTOR SYSTEM

Abstract

A method for controlling electrical power consumption for a first group of functional which can be used for operational management during operation of the bioreactor components during operation comprises, inter alia, adjusting a present power control signal for one or more of the functional components from the first group in order to optimise power consumption, when a comparison shows for the first group of functional components that the currently required total electrical power consumption is greater than a predefined total electrical power consumption, such that, for the first group of functional components, an adjusted total electrical power consumption is not greater than the predefined total electrical power consumption. A biotechnological apparatus comprises a bioreactor, a reactor vessel formed in the bioreactor and having a cultivation chamber, and a temperature control device provided with a heat pump and configured to control the temperature of the cultivation chamber.

Claims

1.-13. (canceled)

14. A biotechnological apparatus comprising: a bioreactor, a reactor vessel formed in the bioreactor and having a cultivation chamber, and a temperature control device provided with a heat pump and configured to control the temperature of the cultivation chamber, wherein the heat pump is thermally coupled to the cultivation chamber via the reactor vessel and to a reference body forming a heat source potential for the heat pump and made of a heat-conducting material, and transfers useful heat, with supply of drive energy, from the reactor vessel to the reference body, or vice versa.

15. The apparatus according to claim 14, wherein the heat pump is a heat pump which can be driven by electrical drive energy.

16. The apparatus according to claim 14, wherein the reactor vessel is arranged in a vessel receptacle and the heat pump is thermally coupled to the reactor vessel via the vessel receptacle.

17. The apparatus according to claim 14, wherein the reference body is thermally coupled to an operating environment of the bioreactor.

18. The apparatus according to claim 17, wherein the reference body is thermally coupled to the operating environment of the bioreactor via an adjustable thermal resistance.

19. The apparatus according to claim 14, wherein the heat pump is coupled to a controller which is configured to control, during operation of the bioreactor, the supply of drive energy for transferring the useful heat from the reactor vessel to the reference body, or vice versa, in accordance with a predefined operational management scheme.

20. A bioreactor system comprising a plurality of biotechnological apparatuses, each comprising: a bioreactor, a reactor vessel formed in the bioreactor and having a cultivation chamber, and a temperature control device configured to control the temperature of the cultivation chamber and provided with a heat pump which is thermally coupled to the cultivation chamber via the reactor vessel and to a reference body made of a heat-conducting material, and transfers useful heat, with supply of drive energy, from the respective reactor vessel to the reference body, or vice versa, wherein the reference body forms a shared heat source potential for the heat pumps of the plurality of biotechnological apparatuses.

21. A method for controlling the temperature of a cultivation chamber in a biotechnological apparatus having a bioreactor, a reactor vessel formed in the bioreactor with a cultivation chamber, and a temperature control device, the method comprising: supplying a setpoint value for a cultivation temperature in the cultivation chamber to a setpoint value input of a temperature controller, detecting a process value for the cultivation temperature using a temperature sensor unit and supplying the process value to a process value input of the temperature controller, and generating a temperature control signal by processing the setpoint value and the process value for the cultivation temperature in the temperature controller, outputting the temperature control signal via an output of the temperature controller, and receiving of the temperature control signal by a heat pump controller and controlling of the input of drive energy into the heat pump by the heat pump controller according to the temperature control signal.

22. The method according to claim 21, wherein external temperature control is performed by means of the temperature controller and internal temperature control is performed by means of an additional temperature controller, the method further comprising: supplying the temperature control signal outputted by the temperature controller to a setpoint value input of the additional temperature controller, detecting a process value for the temperature of a heat exchanger via which the heat pump is thermally coupled to the reactor vessel, by at least an additional temperature sensor unit and supplying the process value to a process value input of the additional temperature controller, generating an adjusted temperature control signal by processing the setpoint value and the process value in the additional temperature controller, outputting the adjusted temperature control signal via an output of the additional temperature controller, and receiving of the adjusted temperature control signal by the heat pump controller and controlling of the input of drive energy into the heat pump by the heat pump controller according to the adjusted temperature control signal.

23. The method according to claim 21, wherein the method further comprising: supplying a power control signal corresponding to the temperature control signal/the adjusted temperature control signal to a setpoint value input of a power controller included in the heat pump controller, detecting a process value for electrical power consumed by the heat pump and supplying the process value to a process value input of the power controller, generating an adjusted power control signal by processing the setpoint value and the process value in the power controller, outputting the adjusted power control signal via an output of the power controller, and receiving of the adjusted power control signal by a controller of the heat pump controller assigned to the heat pump and controlling of the input of drive energy into the heat pump by at least the controller in accordance with the adjusted power control signal.

24. A method for controlling the temperature of cultivation chambers in the bioreactor system of claim 20 comprising a plurality of biotechnological apparatuses, each apparatus having a bioreactor, a reactor vessel formed in the bioreactor and having a cultivation chamber, and a temperature control device, wherein the temperature in one or a plurality of the cultivation chambers is controlled by a temperature control method according to claim 22.

25. The method according to claim 24, characterised in that, in an operating phase of the bioreactor system, the heat pump of the temperature control device of one of the plurality of biotechnological apparatuses transfers useful heat from the reactor vessel to the reference body to cool the cultivation chamber, and the heat pump is assigned to the temperature control device of another of the plurality of biotechnological apparatuses, in order to transfer useful heat from the reference body to the reactor vessel in order to heat.

Description

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0099] The invention shall now be described with reference to preferred embodiments and to the Figures, in which

[0100] FIG. 1 shows a view of a biotechnological apparatus comprising a bioreactor system formed by a plurality of bioreactors,

[0101] FIG. 2 shows a view of a temperature controller of the bioreactor system in FIG. 1,

[0102] FIG. 3 shows a sectional view of the temperature controller in FIG. 2,

[0103] FIG. 4 shows a schematic view of a biotechnological apparatus comprising a bioreactor system formed by a plurality of bioreactors which are each thermally coupled, via a heat pump, to a shared source or main thermal potential,

[0104] FIG. 5 shows another schematic view of the biotechnological apparatus in FIG. 4, with a control unit assigned thereto,

[0105] FIG. 6 is a graph showing the dependency of the efficiency (in percent) of an electrically controllable heat pump in dependency on the temperature differential ΔT between thermally coupling faces and

[0106] FIG. 7 is a graph showing how the efficiency (in percent) of a heat pump depends on the temperature differential ΔT.

[0107] FIG. 1 shows a schematic view of a biotechnological apparatus comprising a bioreactor system embodied with a plurality of bioreactors 1.1, . . . , 1.4, which are releasably received for operation in respectively assigned openings 3.1 . . . 3.4 in a base block 2, such that each of the plurality of bioreactors 1.1 . . . 1.4 is coupled to a temperature controller which is disposed in base block 2. Bioreactors 1.1 . . . 1.4 are each fitted with connection members 4.1 . . . 4.4 for supplying or removing fluids necessary for operation.

[0108] An arrangement 5 with containers is formed on base block 2.

[0109] According to FIG. 1, two more functional blocks 6, 7 are also arranged in a stack on basic functional block 2, which can be removed and which can receive a gas mixing station, for example, and/or one or more pumps.

[0110] In the base block 2 of the bioreactor system in FIG. 1, a temperature controller for bioreactors 1.1, . . . , 1.4 is implemented, and which is used to adjust, during operation of bioreactors 1.1 . . . 1.4, the operating conditions in respect of temperature desired for cultivation. The temperature controller shall now be described in more detail with reference to FIGS. 2 and 3, which show a schematic view of a temperature control device of the bioreactor system in FIG. 1 and a cross-section of the temperature control device shown in FIG. 2.

[0111] According to FIG. 2, a power unit 21 and control electronics 22 are arranged adjacent to each other in a housing 20. On one housing rear side 23, fans 24, 25 are integrated into the wall of housing 20, which are assigned to and cooperate with a reference body 26 (cf. FIG. 3) acting as a heat source potential, in such a way that fans 24, 25 generate an flow of air for reference body 26 that has the temperature of the operating environment of the bioreactor system, in order in this way to ensure heat exchange between the ambient air and reference body 26.

[0112] According to FIG. 3, openings 3.2, 3.4 for bioreactors 1.2, 1.4 are formed in respective vessel receptacles 27.2, 27.4, each of which is thermally coupled to a heat pump 28.2, 28.4 disposed thereunder, which for its part is then thermally coupled to the reference body 26 which is located thereunder and which forms the main thermal potential. In the embodiment shown here, heat pumps 28.2, 28.4 are each formed by at least one Peltier element, that is, they are embodied as heat pumps which can be driven by electrical energy. By supplying electrical drive energy, heat pumps 28.2, 28.4 are driven during operation of the bioreactor system in order to induce a transfer of heat from the respective vessel receptacle 27.2, 27.4 to reference body 26, or vice versa. In this way, the temperature of the respective vessel receptacle 27.2, 27.4, which thus acts as a heat exchanger, and ultimately that of the associated bioreactor 1.2, 1.4 is controlled in operation, be it to cool it or to heat it.

[0113] As can be seen from FIG. 2, reference body 26 has cooling fins 29 which are formed along its overall length. Between cooling fins 29, the air flow produced by fans 24, 25 flows.

[0114] The structure and function of the temperature controller or regulator for the bioreactors shall now be described in the following with reference to FIGS. 4 to 7. In FIGS. 4 and 5, the same reference signs for the same features as in FIGS. 1 to 3 are used.

[0115] FIG. 4 shows a schematic view of a biotechnological apparatus comprising a bioreactor system formed by a plurality of bioreactors 1.1, . . . , 1.n which are each thermally coupled, via an associated heat pump 28.1, . . . , 28.n, to a shared source or main thermal potential formed by reference body 26.

[0116] Reference body 26 consists of a material with high thermal conductivity. The present temperature of reference body 26 is designated T0, and its specific heat capacity CH0. The plurality of bioreactors 1.1, . . . , 1.n are unilaterally thermally coupled to the reference body 26 forming the main thermal potential. Bioreactors 1.1, . . . , 1.n each comprise a reactor vessel 30.1, . . . , 30.n which is arranged in the associated vessel receptacle 27.1, . . . , 27.n, and the cultivation chamber 31.1, . . . , 31.n of which is partially filled with a culture 32.1, . . . , 32.n being cultivated. Vessel receptacle 27.1, . . . , 27.n is thermally insulated on the outside against the surroundings by means of insulation means 33.1, . . . , 33.n.

[0117] In the respectively assigned heat pump 28.1, . . . , 28.n, which is preferably designed as an electrically driven heat pump, for example by means of at least one Peltier element, a positive or negative flow of heat Qi is induced from reference body 26 to vessel receptacle 27.1, . . . , 27.n, or vice versa, depending on how the heat pump is controlled. Two heat loss flows Qlossi/2, which are always positive, are added to this flow of heat.

[0118] According to FIG. 4, reference body 26 is thermally coupled to the operating environment 35 via a thermal resistance 34. Operating environment 35 has the current, predefined temperature Tamb. A flow of heat between reference body 26, which forms the main thermal potential, and operating environment 35 equates to Q.sub.Amb=(T.sub.amb−T.sub.0)/R.

[0119] By suitable variation of the thermal resistance 34, Q.sub.Amb and T.sub.0 can be suitably controlled within desired ranges during operation of the bioreactor. In practice, the variably adjustable heat transfer can be carried out with the aid of the combination of a heat sink and a controllable fan device (in this regard, see also the description above in respect of FIGS. 2 and 3).

[0120] According to FIG. 4, an electrical power supply 36 is also provided for heat pumps 28.1, . . . , 28.n, for which a maximum power level S.max is predefined.

[0121] The efficiency of electrically controllable heat pumps is significantly affected by the temperature differential between the two coupling faces. This relationship is represented qualitatively in the following FIGS. 6 and 7. FIG. 6 is a graph showing the dependency of the efficiency (in percent) of an electrically controllable heat pump in dependency on the temperature differential ΔT between thermally coupling faces.

[0122] The maximum efficiency is achieved when ΔT=0K, and the efficiency decreases with increasing temperature differential. The inputted power is split into an effective heat flow Qi and a heat loss flow Qlossi. Whereas the heat loss flows make a positive contribution, from the perspective of the process target, when heating the culture they deteriorate the situation in the case of cooling. These relationships are illustrated in FIG. 7 for a given power inputted to the heat pump (curve A−Qeff). FIG. 7 is a graph showing how the efficiency (in percent) of a heat pump depends on the temperature differential T. Whereas in the case of heating (to the right of the y-axis) a large proportion of the inputted power directly benefits the biological culture, the efficiency decreases strongly with increasing temperature differential in the case of cooling (to the left of the y-axis). To achieve an optimal design of the system as a whole (maximum efficiency), the setpoint temperature T0.SP (SP=“Set Point”=setpoint value) of the main potential should therefore be made less than or equal to the setpoint temperature T1i.SP of the cultures in the bioreactors.

[0123] Control mechanisms for controlling the temperature in bioreactors 1.1, . . . , 1.n shall now be described in more detail with reference to FIG. 5.

[0124] Heat pumps 28.1, . . . , 28.n are each thermally coupled to reference body 26, which forms the main thermal potential. In a typical operational management system, a plurality of bioreactors 1.1, . . . , 1.n are heated, which corresponds to a positive flow of heat from reference body 26 to the respective bioreactor. This results in reference body 26 cooling down. If one or more other bioreactors are cooled at the same moment of operation, this leads to positive heat exchange flows from the heat pumps assigned to these bioreactors to reference body 26. If operational management is ideal, the exchanges of heat to and from reference body 26 complement each other in such a way that no change in the temperature of reference body 26 occurs, or only a very slight change of temperature. The system as a whole then operates with maximum energy efficiency.

[0125] For by far the greatest proportion of biological metabolisms, the optimal and hence also the typical temperature range for such applications is between about 25 and 40° C. The metabolic processes are accompanied by the biological systems generating (specific) heat, the maximum of which is therefore likewise within the aforementioned temperature range. The bioreactor systems preferably considered her are typically operated in laboratory rooms having an ambient temperature Tamb of approximately 20 to approximately 30° C. When appropriately dimensioned, T0 of the reference body 26 may therefore be operated close to Tamb. In this situation, with T1i, T2i within the biologically relevant operating range of approximately 25 to approximately 40° C., and T0 close to Tamb at approximately 20 to approximately 30° C., the temperature differential between the coupling faces of heat pumps 28.1, . . . , 28.n is small, as a result of which their efficiency is high.

[0126] If the dynamics of the metabolic process in one or several of the cultures are now to be changed at a given moment, which corresponds to the cooling function that is frequently used in practice, the system starts close to the working point that is ideal in this respect. Although the efficiency of the heat pumps in question decreases in the course of cooling, due to the increasing temperature differential between the coupling faces, the biological activity also decreases simultaneously, as does the specific generation of heat by the cultures, with the result that the effects partially compensate for each other.

[0127] According to FIG. 5, the setpoint value (SP) for the culture temperature T1i.SP (i=1, . . . , n) is predefined to an external temperature controller 40, which may be a modified PID controller, for example, that is implemented at least partially by means of the operating software. The setpoint value (SP) for the culture temperature T1i.SP is given to a setpoint value input 41 of the external temperature controller 40. A process value T1i.PV (PV—“Process Value”) is given to a process value input 42 of the external temperature controller 40. The controller output signal is calculated by comparing the setpoint temperature and the process temperature T1i.PV and by taking into account the controller parameter, and it is outputted via an output terminal 43 of the external temperature controller 40. This signal is simultaneously the setpoint temperature for vessel receptacle 27.1 with the designation T2i.SP, which is given to an internal temperature controller 44 at a setpoint value input 45. The process value T2i.PV is applied to the process value input 46 of the internal temperature controller 44.

[0128] The maximum temperature differential between the temperature in the cultivation chamber 31.1 and the temperature in the reactor vessel 30.1 or in vessel receptacle 27.1 can be defined by suitable upper and lower limits for the value T2i.SP, either in absolute terms or relative to the culture temperature T1i.SP or T1i.PV. Damage to the biological systems due to overheating or overcooling can be prevented effectively in this way.

[0129] The internal temperature controller 44, which may also be a modified PID controller implemented by means of software, for example, calculates a controller output signal Pi.SP from the setpoint value T2i.SP and the process value of the vessel receptacle 27.1 T2i.PV, taking the controller parameters into account. The controller output signal Pi.SP is outputted via an output terminal 47 and is applied to a control block 50. By suitably limiting this setpoint value Pi.SP, heat pump 28.1 can be protected against overload. It is also possible in this way to implement load distribution throughout the system, as will be described in more detail below. Control block 50 is used in this regard to implement the higher-level power management. An adjusted control signal Pi.SP′ is outputted via an output terminal 53 and is supplied to a setpoint value input 48 of power controller 49 (see below for further description).

[0130] The process value Pi.PV is supplied to the process value input 51 on power controller 49. Power controller 49 controls a controller 52 of heat pump 28.1 such that the process value of the power Pi.PV induced into heat pump 28.1 corresponds to the setpoint value Pi.SP′ which is outputted by control block 50. The process value Pi.PV of the induced power is typically determined in the case of electrical heat pumps by measuring current consumption and voltage supply. The efficiency of controller 52, which is realised by PWM full bridges, for example, and which is also referred to as “power electronics of the associated heat pump”, may be arithmetically taken into account, as indicated by way of example in the following table:

TABLE-US-00001 Supply voltage of the power electronics U Measured current consumption of the power electronics I.sub.i of heat pump i Power transferred from the power supply to the power P.sub.Total i = electronics of heat pump i, which is taken into account in U .Math. I.sub.i the power balance for the system as a whole. Shunt resistance of current measurement R.sub.S Power loss from current measurement i P.sub.Loss i = R.sub.S .Math. I.sub.i.sup.2 Efficiency of the power electronics i (PWM full bridge) η.sub.i Process value of the power transferred at heat pump i P.sub.iPV = (Process Value = PV), which is used for optimised power η.sub.i .Math. (P.sub.Total i − control of heat pump i. P.sub.Loss i) P.sub.iPV = η.sub.i .Math. (U .Math. I.sub.i − R.sub.S .Math. I.sub.i.sup.2)

[0131] In the embodiment described by way of example, power controller 49 compensates for the nonlinearities and serial spreads that frequently occur in practice in respect of heat pump 28.1. Power controller 49 actively linearises the behaviour of heat pump 28.1 that is in use. Component variances are also compensated by the direct measurement of power. A robust controller is thus formed which also works efficiently, since it is not necessary during production to sort elements.

[0132] In a simplified embodiment, the output signal of the external temperature controller 40 can be used directly to control controller 52, by leaving out the internal temperature controller 44 and the power controller 49. In an alternative embodiment, the internal temperature controller 44 can be connected downstream from the external temperature controller 40, without power controller 49 being used. In another embodiment, output 43 can be given directly to the setpoint value input 48 of power controller 49.

[0133] The dynamics of the control loop increase with the external temperature controller 40, the internal temperature controller 44 and the power controller 49 analogously with the (continuously decreasing) heat capacities of the respective system components to be subjected to temperature control. Typical adjustment speeds of power controller 49 range from a few milliseconds to a maximum of one second. The control dynamics of the internal temperature controller 44 typically range from several seconds to a few minutes. The adjustment speed of the external temperature controller 40 can normally span a range from single-digit to two-digit minute values.

[0134] The interconnected control loops each linearise the transfer characteristics of the controlled systems assigned to them. This results in very exact and narrowly defined control with considerable robustness.

[0135] Each of the interconnected control loops is optimally adjusted in respect of its control parameters to the dynamic transfer characteristics of the controlled system assigned to it. To achieve this, the dynamic behaviour of the control loops can be determined experimentally in advance, and information about the determined dynamics, for example the operating parameters characterising the dynamic behaviour, can be stored in software. Such an approach is well-known as such and does not require any further explanation here. In this way, optimal control dynamics for the system as a whole are achieved.

[0136] A further controller 54 controls the thermal resistance 34 of the coupling between the reference body 26 forming the main potential and the surrounding 35, according to the setpoint and process value of temperature TO and the present load situation. It uses an actuating member 55 for that purpose, which may take the form of fans 24, 25, for example.

[0137] By specifically defining and controlling the maximum temperature differentials between the temperature in cultivation chamber 31.1, . . . , 31.n and the temperature of reactor vessel 30.1, . . . , 30.n/of vessel receptacle 27.1, . . . , 27.n, possible damage caused to the biological systems in the culture by overheating or over-cooling are actively prevented. This can also be ensured for transients/transfers, due to the strong system dynamics of the internal temperature control loops comprising controllers 44, 49.

[0138] For reasons of cost efficiency and also for electrical safety reasons, the device for managing the bioreactor temperatures may be operated with multi-voltage power supply units, so called, which convert the country-specific primary voltage into a uniform safe extra-low voltage.

[0139] Control block 50 (cf. FIG. 5), in particular, sums the power consumptions of all n-setpoint values Pi.SP. This summed signal P.sum is used for load distribution throughout the system, in particular for managing distribution of the electrical power individually allocated to heat pumps 28.1, . . . , 28.n. Other functional components of the biotechnological apparatus can also be included in such a (higher-level) power management system, or the latter may be provided only for functional components in which heat pumps 28.1, . . . , 28.n are not even included. It is therefore assumed in the following that the group in question is any arbitrary group of functional elements of the biotechnological apparatus, which in a special case may then be heat pumps 28.1, . . . , 28.n.

[0140] The functional components Pi have the following characteristics:

TABLE-US-00002 Pi.max Maximum power consumption of functional component Pi Pi.SP Power setpoint value predefined by higher-level operational |Pi.SP| <= Pi.max management system. The value of Pi.SP is always less than or equal to Pi.max, thus preventing in an effective manner any overloading of the actuating member, in particular. By modifying Pi.SP on a time-dependent basis, for example by means of an integrating control portion, the high-level load management system can affect the prioritisation of the functional components in the power management allocation procedure (see below for more detail). Pi.SP′ Power setpoint value allocated by the power management |Pi.SP′| <= |Pi,SP| system according to a specific distribution strategy. The value of Pi.SP′ is not greater than the value of Pi.SP. In the embodiment above, the latter value is supplied as a valid setpoint value to power controller 49. (For switching actuating members, Pi.SP′ is either equal to Pi.SP or zero.) Pi.PV Process value for the power consumption of the functional component Pi. (Is set, for example, by means of power controller 49, usually in highly dynamic manner, according to the set according to the predefined setpoint value Pi.SP′.) Pi.σ Typical percentual dynamic variation in power Pi.PV. May be relatively small if controller is well designed, for example within a range of 1 to 3%.

[0141] The biotechnological apparatus may also comprise other functional components Fj (j=1, . . . , m) which are not subjected directly to power management, but which instead supply external, time-based conditions for power management. Typical embodiments for the other functional components Fj are stirrer drives, gas mixing systems, valves and/or pump drives.

[0142] In contrast to functional components Pi, for which a slight delay in adjustment caused by reduced power allocation can easily be coped with, certain functional components must be able to perform their function in full at all times. For that reason, such components should not be disrupted by reduced power allocation, which can otherwise occur under the proposed power management system.

[0143] The other functional components Fj have the following characteristics:

TABLE-US-00003 Fj.max Maximum power consumption of the other functional components Fj, which is safeguarded with the aid of a power controller assigned directly to the respective other functional component. Fj.PV Process value for the power consumption of the other |Fj.PV| <= functional component Fj Fj.max Fj.σ Percentual dynamic variation in power Fj.PV

[0144] A power supply S is provided for functional components Pi and for the other functional components Fj, namely by electrical power supply 36 in the embodiment described above.

[0145] The power supply S has the following characteristics.

TABLE-US-00004 S.max Maximum output power of power supply S. (The maximum power output may vary within a certain range over time, depending on external factors such as time of day, temperature of the operating environment or energy prices, but may not fall under a predefined minimum value.) S.PV <= Present power output of energy supply S. S.max

[0146] In order to specify the minimum output power S.max, the electrical power consumptions for functional components Pi and for the functional components Fj can be based, if known, on simultaneity factors. The following variant is based on a simultaneity of the other functional components Fj of 1, i.e. all the components can be operated simultaneously with Fj.max.

[0147] The first step is to determine the sum of the maximum power consumptions of the functional components Pi:

[00005]$P.Math.\max =\underset{i=1}{\overset{n}{.Math.}}.Math..Math.\mathrm{Pi}.Math.\max$

[0148] The sum of the maximum power consumptions of the other functional components Fj is then calculated:

[00006]$F.Math.\max =\underset{j=1}{\overset{n}{.Math.}}.Math..Math.\mathrm{Fj}.Math.\max$

[0149] The minimum value of the maximum power output of power supply S is dimensioned:

[00007]$S.Math.\max =\alpha .Math.\underset{i=1}{\overset{n}{.Math.}}.Math..Math.\mathrm{Pi}.Math.\max +\underset{j=1}{\overset{m}{.Math.}}.Math..Math.\mathrm{Fj}.Math.\max$

[0150] Factor α is theoretically within the range [0 . . . 1] and is usually selected, depending on application, in the range [0.2 . . . 0.8], for example.

[0151] In the biotechnological apparatus described above, with heat pumps 28.1, . . . , 28.n (cf. FIG. 5), the biggest proportion of the installed power rating is usually found in the functional elements Pi for temperature control.

[0152] The complete installed power of heat pumps 28.1, . . . , 28.n is required in rare cases only; furthermore, there is only a slight probability in such cases that the maximum power Fj.max will be required by the other functional components Fj. This means that the factor a can be selected with a relatively low value [0.2, . . . , 0.5]. This avoids any over-dimensioning of the power supply, with the concomitant negative consequences such as costs, power loss, cut-in currents, etc.

[0153] In the following, a method for determining the distribution of electrical power consumption shall be described with an example. In the first step, the present operating situation with regard to electrical power consumption is determined.

[0154] The total required power consumption of the functional elements Pi is determined. As an option, an individual dynamic reserve may be taken into account here using a variation Pi.σi, i.e. in the case where Pi.σi>0:

[00008]$P.Math.\mathrm{sum}=\underset{i=1}{\overset{n}{.Math.}}.Math..Math.\left(1+\mathrm{Pi}.Math.\sigma .Math..Math.i\right).Math..Math.\mathrm{Pi}.Math.\mathrm{SP}.Math.,$

[0155] The present process value for the total power consumption of the other functional elements Fj is also determined. An individual dynamic reserve is taken into account here using the variation Fj.σ, i.e. in the case where Fj.σ>0:

[00009]$F.Math.\mathrm{sum}=\underset{j=1}{\overset{m}{.Math.}}.Math..Math.\left(1+\mathrm{Fj}.Math.\sigma .Math..Math.j\right).Math..Math.\mathrm{Fj}.Math.\mathrm{PV}.Math.,$

[0156] In this way, the individual power consumptions of the functional components Pi and/or of the other functional elements Fj can be dynamically altered, as an option, for example to take different operating situations into consideration.

[0157] The total power S.sum required in the present operating situation is determined:

S.sum=P.sum+F.sum

[0158] If S.sum is less than or equal to the currently available maximum output value of power supply S.max, all the functional elements Pi can be reliably provided with the required power:

∀.sub.iPi.SP′=Pi.SP

[0159] However, if S.sum is greater than the currently available maximum output power of power supply S.max, then an appropriate strategy for distributing the available power among the functional elements Pi must be applied in order to maintain reliable operation. Alternative variants are available for this purpose.

[0160] In one variant, the total power P.sum′ that can be distributed to the functional elements Pi is determined:

P.sum′=S.max−F.sum

[0161] One preferred embodiment endeavours to continue an existing relative distribution of power among the functional elements Pi. A reduction factor x is calculated for this purpose, which lies within the range α . . . 1:

[00010]$x=\frac{P.Math.{\mathrm{sum}}^{\prime }}{P.Math.\mathrm{sum}}$

[0162] In a further step, the individual power setpoint values Pi.SP′ are calculated as follows:

∀.sub.iPi.SP′=x.Math.Pi.SP

[0163] The system as a whole is managed safely and reliably on the basis of these reduced power setpoint values.

[0164] The precondition for implementing the power control concept described above is that the functional elements Pi are amenable to at least one of the following kinds of control: [0165] Elements are involved whose individual power consumption can be altered/adjusted. [0166] Several elements with a constant (unchangeable) power consumption are involved, but these can be switched on and off either individually or in groups.

[0167] Controlled provision of power for the system or functional components may be carried out according to averaging all the components involved, such that each functional component is provided the same share of power. As an alternative or in addition thereto, the system components may be weighted when supplying power. For example, selected system components may be provided at all times with their maximum power requirement. Or such system components may be completely excluded from any shutdowns. A reduction in the supplied power may also be limited for such system components to a certain percentual amount, for example to 30% of the normal/maximum power consumption.

[0168] The proposed load management system can be realised for any combination of system or functional components of the bioreactor system. The above description for a particular embodiment was based on temperature control devices. Similarly, a common load management system may be provided, for example, for stirrers and/or temperature control devices which are assigned to a respective bioreactor in the bioreactor system.

[0169] The features of the invention which are disclosed in the above description, in the claims and in the drawings may be material in their various embodiments, both separately and in any combination, for realising the invention.