Abstract
A control method for a heat transfer system, wherein the heat transfer system comprises a supply conduit (12), at least one load circuit (2) and a heat transfer device (6; 28) between the supply conduit and the at least one load circuit, wherein a supply flow (qS) in the supply conduit (12) is detected on the basis of a desired entry-side load temperature (Tref), of an actual entry-side load temperature (TL) which is detected in the load circuit (2) and of a load flow (qL) in the load circuit (2), as well to as a heat transfer system, in which such a control method is applied.
Claims
1. A control method comprising: providing a heat transfer system comprising a supply conduit, at least one load circuit and a heat transfer device arranged in a flow direction between the supply conduit and the at least one load circuit; setting a desired supply flow in the supply conduit on the basis of: a desired entry-side load temperature; an actual entry-side load temperature which is detected in the load circuit; and a load flow in the load circuit, wherein one of heat is transferred from the supply conduit to the load circuit and the load circuit is cooled via the supply conduit, the load circuit comprising at least one of a cooling circuit and a heating circuit for at least one of cooling and heating one of an object and a building, the at least one of the cooling circuit and the heating circuit defining one of a closed circuit and a closed conduit for fluid flow in the one of the closed circuit and the closed conduit, wherein one of a valve opening degree and a speed of a pump is determined in a next step based on the desired supply flow.
2. A control method according to claim 1, wherein the supply flow is controlled based at least a position of the valve, wherein heat from the supply circuit is transferred to the load circuit via the heat transfer device.
3. A control method according to claim 1, wherein the heat transfer device comprises at least one heat exchanger with a first flow path which is connected to the supply conduit and with a second flow path which is connected to the at least one load circuit.
4. A control method according to claim 1, wherein the heat transfer device comprises at least one mixing conduit which connects an outlet of the at least one load circuit and an entry of the load circuit to one another.
5. A control method according to claim 1, wherein the supply flow is set additionally on the basis of at least one of: an exit-side load temperature; and an entry-side supply temperature.
6. A control method according to claim 1, wherein the supply flow is set additionally on the basis of at least one of: at least one constant linked to the load flow; and a desired entry-side load temperature.
7. A control method according to claim 1, wherein the load flow is determined according to the following equation: wherein: q.sub.S is the supply flow; q.sub.L is the load flow; T.sub.S is the entry-side supply temperature; T.sub.RS is the exit-side supply temperature; and V is a control signal.
8. A control method according to claim 7, wherein the control signal V is the output signal of a regulator or is determined according to the equation:
V=T.sub.refT.sub.RS or by combination of this equation with the output signal of a controller, wherein: T.sub.ref is the desired entry-side load temperature; and T.sub.RS is the exit-side load temperature.
9. A control method according to claim 1, wherein the supply flow is set by a pump and a speed n of the pump is determined on the basis of the following equation: wherein: q.sub.S is the supply flow; and K.sub.qn is a time-dependent signal which is dependent on the flow resistance in the supply conduit.
10. A control method according to claim 2, wherein for determining a speed (n) of the pump or for determining an opening of the valve, a differential pressure across the pump or across the valve is taken into account.
11. A control method according to claim 1, wherein a transfer delay between a measurement point of the entry-side load temperature and the heat transfer device is taken into account by way of at least one constant and/or a function dependent on the load flow, on setting the supply flow.
12. A control method according to claim 1, wherein the load flow in the load circuit is determined via a load pump.
13. A heat transfer system comprising: a supply conduit; at least one load circuit, the load circuit comprising at least one of a closed loop cooling circuit and a closed loop heating circuit for at least one of cooling and heating one of an object and a building, the at least one of the closed loop cooling circuit and the closed loop heating circuit comprising one of a closed circuit and a closed conduit for fluid flow in the one of the closed circuit and the closed conduit, wherein one of heat is transferred from the supply conduit to the load circuit and the load circuit is cooled via the supply conduit; a heat transfer device arranged in a flow direction between the supply conduit and the at least one load circuit; and a supply flow setting device which sets a desired supply flow, wherein the supply flow setting device comprises at least one control device configured to carry out a control method comprising: setting the desired supply flow in the supply conduit on the basis of: a desired entry-side load temperature; an actual entry-side load temperature which is detected in the load circuit; and a load flow in the load circuit, wherein a flow regulator regulates the supply flow by setting a valve, wherein one of a valve opening degree and a speed of a pump is determined in a next step based on the desired supply flow.
14. A heat transfer system according to claim 13, wherein heat from the supply circuit is transferred to the at least one load circuit via the heat transfer device, the heat transfer system further comprising: a sensor device detecting an entry-side load temperature of the load circuit; a sensor device detecting a load flow in the load circuit; and a temperature detection device for detecting at least one of an exit-side load temperature and an entry-side supply temperature.
15. A heat transfer system according to claim 13, wherein a degree of valve opening of the valve is set by the control device, wherein the supply flow is controlled based on a position of the valve.
16. A heat transfer system according to claim 13, wherein the heat transfer device comprises one of: at least one heat exchanger which comprises a first flow path connected to the supply conduit and a second flow path connected to the at least one load circuit; and a mixing conduit which connects the exit side of the at least one load circuit to the entry side of the load circuit.
17. A heat transfer system control method comprising the steps of: providing a heat transfer system comprising a supply conduit, a flow regulator comprising a valve, at least one load circuit, a heat transfer device arranged in a flow direction between the supply conduit and the at least one load circuit and a supply flow setting device which sets a supply flow, wherein the supply flow setting device comprises at least one control device, the load circuit comprising at least one of a closed loop cooling circuit and a closed loop heating circuit for at least one of cooling and heating one of an object and a building, the at least one of the closed loop cooling circuit and the closed loop heating circuit comprising one of a closed circuit and a closed conduit for fluid flow in the one of the closed circuit and the closed conduit, wherein one of heat is transferred from the supply conduit to the load circuit and the load circuit is cooled via the supply conduit; and setting the supply flow in the supply conduit with the at least one control device on the basis of: a desired entry-side load temperature; an actual entry-side load temperature which is detected in the load circuit; and a load flow in the load circuit, wherein the flow regulator receives a set supply flow value as input, the flow regulator regulating the supply flow by controlling the valve based on the set supply flow value.
18. A control method according to claim 17, wherein heat from the supply circuit is transferred to the load circuit via the heat transfer device, wherein the supply flow is controlled based on one of a speed of the pump and a position of the valve.
19. A control method according to claim 17, wherein the heat transfer device comprises at least one heat exchanger with a first flow path which is connected to the supply conduit and with a second flow path which is connected to the at least one load circuit.
20. A control method according to claim 17, wherein the heat transfer device comprises at least one mixing conduit which connects an outlet of the at least one load circuit and an entry of the load circuit to one another.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1a is a schematic view showing a heat transfer system according to the invention, with a mixing circuit;
(2) FIG. 1b is a schematic view showing a heat transfer system according to the invention, with a heat exchanger;
(3) FIG. 2 is a schematic view showing a characteristic field which represents the relationship between a signal proportional to the valve opening and the differential pressure across the valve as well as the flow;
(4) FIG. 3 is a schematic view showing the control of a valve for setting the supply flow according to a first embodiment of the invention;
(5) FIG. 4 is a schematic view showing a speed control of a pump for setting a supply flow according to a further embodiment of the invention;
(6) FIG. 5 is a schematic view showing the regulation of the supply flow with the help of a separate flow regulator;
(7) FIG. 6 is a schematic view showing a simplified control of a valve for setting the supply flow;
(8) FIG. 7a is a schematic view showing one of six different heat transfer systems according to the invention with mixing circuits and different sensor and actuator elements;
(9) FIG. 7b is a schematic view showing another of six different heat transfer systems according to the invention with mixing circuits and different sensor and actuator elements;
(10) FIG. 7c is a schematic view showing another of six different heat transfer systems according to the invention with mixing circuits and different sensor and actuator elements;
(11) FIG. 7d is a schematic view showing another of six different heat transfer systems according to the invention with mixing circuits and different sensor and actuator elements;
(12) FIG. 7e is a schematic view showing another of six different heat transfer systems according to the invention with mixing circuits and different sensor and actuator elements;
(13) FIG. 7f is a schematic view showing another of six different heat transfer systems according to the invention with mixing circuits and different sensor and actuator elements;
(14) FIG. 8 is a schematic view showing the control of a valve for setting the supply flow amid the use of a regulation of the entry-side load temperature;
(15) FIG. 9 is a schematic view showing a control according to FIG. 8 with a compensation of the occurring temperature delay;
(16) FIG. 10 is a schematic view showing a variant of the control according to FIG. 9; and
(17) FIG. 11 is a schematic view showing a simplified variant of the control according to FIG. 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
(18) Referring to the drawings, the heat transfer system shown in FIG. 1a comprises a load circuit 2 as well as a supply or a supply circuit 4. A heat transfer device in the form of a mixing circuit with a mixing conduit 6 is arranged between the supply 4 and the load circuit 2. The mixing conduit 6 connects an outlet 8 to the entry 10 of the load circuit 2. The entry 10 is simultaneously connected to a supply conduit 12 coming from the supply 4. The supply conduit 12 and the mixing conduit 6 meet in a mixing point 14. Thus the fluid flow from the supply conduit and the fluid flow from the mixing conduit 6 are mixed in this mixing point 14 and together get to the entry 10 of the load circuit 2. A valve 16 is arranged in the supply conduit 12 and is settable in its degree of opening, i.e. in particular can be designed as a motorically driven proportional valve, in order to be able to set the mixing ratio of the supply flow q.sub.S in the supply conduit 12 and of the mixing flow q.sub.R in the mixing conduit 6. A check valve 18 is arranged in the mixing conduit 6. The sums of the flows of the supply flow q.sub.S and of the mixing flow q.sub.R forms the load flow q.sub.L in the load circuit 2. This load flow q.sub.L is also produced by a load pump 20. Additionally, three temperature sensors 22, 24 and 26 are arranged in the shown system, of which the temperature sensor 22 detects the entry-side load temperature T.sub.L which the fluid has at the entry 10 of the load circuit 2, and the temperature sensor 24 detects the supply temperature T.sub.S in the supply conduit 12. The supply temperature T.sub.S is the temperature of the fluid which flows through the supply conduit 12. The third temperature sensor 26 in the mixing conduit 6 detects the temperature of the fluid exiting from the load circuit 2, i.e. the exit side load temperature T.sub.RS.
(19) FIG. 1b shows a second variant of the heat transfer system according to the invention, wherein the same components are indicated with the same reference numerals as in FIG. 1a. In contrast to the embodiment example according to FIG. 1a, the heat transfer system according to FIG. 1b does not have a mixing device as a heat transfer device, but a heat exchanger 28. The fluid of the supply circuit or of the supply 4 flows through a first flow path 30 of the heat exchanger 28. Thereby, the supply flow q.sub.S i.e. the flow through the supply circuit, is set via the valve 16 which can be designed in the previously described manner. The supply temperature T.sub.S in the feed flow to the heat exchanger 28 is detected via the temperature sensor 24. The exit-side supply temperature T.sub.RS is detected via the temperature sensor 26. In the embodiment example according to FIG. 1a, the exit-side load temperature which is detected by the temperature sensor 26 likewise corresponds to the exit-side supply temperature T.sub.RS, since the same temperature prevails in the return 32 of the supply circuit.
(20) The heat exchanger 28 in the embodiment example according to FIG. 1b comprises a second flow path 34, through which the fluid of the load circuit 2 flows. The fluid thereby is delivered by the load pump 20. In the example shown here, a further temperature sensor 36 detecting the temperature of the fluid in the outlet 8, i.e. the exit-side load temperature T.sub.RL, is arranged in the outlet 8 of the load circuit 2. The fluid flows via the outlet 8 into the first flow path of the heat exchanger 34 and from there the fluid is heated in the supply circuit 4 and then flows through the entry 10 back into the load circuit 2.
(21) For both previously described variants of a heat transfer system, according to the invention, a new type of control method is applied, with which the supply flow q.sub.S in the supply conduit 12 is set on the basis of the desired entry-side load temperature T.sub.ref, of an actual entry-side load temperature T.sub.L which is detected in the load circuit 2 or in its entry 10 by the temperature sensor 22, as well as of the load flow q.sub.L. The load flow q.sub.L in this example is detected via the load pump. With this, it is the case of a pump assembly which can detect or determine the delivery flow and issue it to a control device for further processing.
(22) The following equilibrium equation for the temperatures and delivery flows results for the arrangement according to FIG. 1a:
(23)
The corresponding following equilibrium equation results for the arrangement according to FIG. 1b:
(24)
The delivery flow can be determined as follows from these equilibrium equations:
(25)
Wherein V can be a control signal or likewise be computed from the measured temperature values in the subsequent manner. If, in the equilibrium equations mentioned above, the temperature T.sub.L, i.e. the entry-side load temperature is replaced by the desired load temperature, i.e. the target value or reference value for the load temperature T.sub.ref, then for the embodiment example according to FIG. 1a it results:
V=T.sub.refT.sub.RS
and for the embodiment example in FIG. 1b:
V=T.sub.refT.sub.RL
(26) In order hereinafter to be able to describe both embodiment examples together, the temperature variable T.sub.R is introduced, which in the case of the use of a mixing circuit corresponds to the temperature T.sub.RS which is the exit-side load temperature and simultaneously the temperature in the return 32 of the supply circuit 4. In the case that a heat exchanger is used, T.sub.R corresponds to the exit-side load temperature T.sub.RL at the exit 8 of the load circuit 2.
(27) (T.sub.refT.sub.R) forms a feedforward factor for a feedforward regulation or control. The term forms the inverse amplification factor of the mixing circuit or of the heat exchanger. According to the equation mentioned above, the supply flow q.sub.S can be set in dependence on the load flow q.sub.L and on the detected temperatures or defined temperatures on the basis of these factors, so that as a whole a more accurate, quicker regulation which is less prone to oscillation can be achieved.
(28) FIG. 2 schematically shows an example of the control or regulation amid the use of a valve 16 in the supply conduit 12. The feedforward factor in the feedforward evaluation 38 is formed by way of subtraction of the temperature value T.sub.R (T.sub.RS or T.sub.RL, depending on whether it is the case of a heat exchanger or mixer) from the desired entry-side load temperature T.sub.ref. In amplification factor evaluation 40, the temperature value T.sub.RS which is determined by the temperature sensor 26 or 26 in the return 32 of the supply 4, is subtracted from the supply temperature T.sub.S which is detected in the supply conduit 12 by the temperature sensor 24. Subsequently, the load flow q.sub.L which is issued by the load pump 20 is divided in the divider 44 by output signal of the subtractor 42. The thus produced signal is subsequently multiplied by the feedforward factor in the multiplier 46, which results in the desired load flow q.sub.S.
(29) If now a valve 16 for setting the load flow q.sub.S is provided in the supply conduit 12, a signal U proportional to the valve opening, is determined for example on the basis of the characteristic field shown in FIG. 2, in the case that it is the case of a non-linear valve, wherein in the evaluation:
(30) the differential pressure Dp.sub.S across the valve is incorporated. This differential pressure can be determined as is explained later by way of FIG. 7.
(31) FIG. 4 shows the control according to FIG. 3, for the case that a pump 48 i.e. a supply pump 48 is applied instead of a valve 16 in the supply conduit 12. For this, the desired speed n must be determined on the basis of the desired supply flow q.sub.S. This is effected according to the equation
(32)
wherein K.sub.qn is a time-dependent signal which depends on the flow resistance in the supply circuit 4 or the supply 4.
(33) FIG. 5 shows a further variant of the control shown in FIG. 3, with which the evaluated supply flow q.sub.S is transferred to a subsequent flow regulator 50 which regulates the supply flow q.sub.S by way of setting the valve 16. Additionally, the detection of the supply flow q.sub.S in the supply conduit 12 or at another location of the supply 4, for example in the return 32, is necessary for such a flow regulation. It is to be understood that such a flow regulation could also be effected amid the use of a pump 48 in a suitable manner, wherein the flow regulator 50 would then not regulate the control signal U for the valve 16, but the speed n for the pump 48.
(34) FIG. 6 shows a further variant of the control which has a simplified construction. With this variant, the evaluation of the feedforward factor in the feedforward evaluation 38 is not effected by way of subtraction of an actually measured temperature signal T.sub.R from the desired entry-side load temperature T.sub.ref. In contrast, here the desire entry-side load temperature T.sub.ref is added to a constant K.sub.0. Accordingly, the load flow q.sub.L is only multiplied by a constant K.sub.1. The constants K.sub.0 and K.sub.1 are constants which are dependent on the installation. These signals are then multiplied in the multiplier, in order to determine the supply flow q.sub.S. On the basis of this flow, a control signal U for the valve 16 is subsequently determined, as in the example according to FIG. 3 amid the use of a characteristic field in FIG. 2 and whilst taking into account the differential pressure Dp.sub.S. The use of constants K.sub.0 and K.sub.1 instead of actually measured temperatures permits a simplified feedforward regulation.
(35) With regard to the evaluation of the control signal U for the valve 16 from a characteristic field as is shown in FIG. 1b, it is to be understood that instead of the measurement of the differential pressure Dp.sub.S in systems, in which only lower pressure fluctuations prevail, a fixed factor can also be used. For the case that it is the case of a linear valve, moreover one can make do without the characteristic field and instead of this the control signal U for the valve 16 can be derived from the delivery flow q.sub.S via an analytic function.
(36) FIGS. 7a-7f show variants of the heat transfer system according to FIG. 1a, with the necessary signal flows to a control device which controls a valve or supply valve 16, 16 or a supply pump 48.
(37) The variant in FIG. 7a differs from the variant in FIG. 1a by way of the fact that the supply valve or valve 16 is not situated in the supply conduit 12 but in the return 32 of the supply 4. However, the same flow prevails in the return 32 as in the supply conduit 12, so that the valve 16, 16 can be selectively arranged in the supply conduit 12 or in the return 32, i.e. the flow in the supply conduit 12 can also be set via the valve 16 in the return 32. The entry-side load temperature T.sub.L is detected via the temperature sensor 22, the supply temperature T.sub.S via the temperature sensor 24 and the exit-side load temperature which corresponds to the exit-side supply temperature T.sub.RS via the temperature sensor 26 in the mixing conduit 6, and their signals are led to the control device 52. Moreover, in this embodiment example, a flowmeter 54 for determining the load flow q.sub.L is arranged in the load circuit 2, in this example in the entry 10. Alternatively, the load flow q.sub.L can be determined directly via the load pump 20, as has been described above. The determined load flow q.sub.L or a signal proportional to this is led to the control device 52. A control method as has been previously described, takes its course in the control device 52, in order to open or close the supply valve 16 in the desired manner or to set the degree of opening of the valve 16. If the arrangement is selected as is shown in FIG. 1a, with the valve 16 in the forward feed of the supply circuit 4, this valve 16 can be linked in a suitable manner to the mentioned sensors and be controlled by the control device 52.
(38) The embodiment variant according to FIG. 7b differs from the previously described arrangement in FIG. 7a b way of the fact that additionally a differential pressure Dp.sub.S in the supply circuit 4 between the feed i.e. the supply conduit 12 and the return 32 is determined. This differential pressure Dp.sub.S is likewise led to the control device 52 and is taken into account by this on determining the control signal U for the valve 16, for example on the basis of a characteristic field, as is shown in FIG. 2, in the manner described above.
(39) FIG. 7c shows a further variant, with which the valve 16 serving as a supply valve is arranged as a mixing valve in the mixing point 14. I.e. it is the case of a 3/2-way valve, via which the mixing of the delivery flows from the mixing conduit 6 and the supply conduit 12 is effected in the desired manner. Thereby, the valve 16 is preferable motorically driven and is controlled or regulated via the control device 52 in the manner described above. This mixing valve 16 also serves for setting the supply flow q.sub.S, since with a reduction of the mixing flow through the mixing conduit 6, the supply flow q.sub.S through the supply conduit 12 is simultaneously increased and vice versa. With the embodiment example in FIG. 7c, in contrast to the embodiment examples according to FIGS. 7a and b, again as also in the embodiment example according to FIG. 1a, the load flow q.sub.L is determined or detected directly by the load pump 20 and led to the control device 52. Moreover, the differential pressure Dp.sub.S across the valve 16 between the supply conduit 12 and the entry 10 of the load circuit 2 is detected via a differential pressure sensor 56. The differential pressure Dp.sub.S is used in the manner described above, in order to determine the control signal U for the valve 16.
(40) The construction shown in FIG. 7d corresponds to that shown in FIG. 1a, with the difference that here a flow sensor 54 for detecting the load flow q.sub.L is present. Additionally, two pressure sensors 58 and 60 are present, wherein the pressure sensor 58 is arranged on the supply conduit 12 and detects the supply pressure P.sub.S, and the pressure sensor 60 is arranged in the mixing conduit 6 and detects the exit-side load pressure P.sub.R which is the same as the exit-side pressure in the return 32 of the supply 4. The pressure sensor 58 can be integrated with the temperature sensor 24 into a sensor. Accordingly, the temperature sensor 24 can be integrated with the pressure sensor 60 into a sensor. Again, a differential pressure Dp.sub.S can be formed in the control device 52 from the pressure signals for the supply pressure P.sub.S and the exit-side load pressure P.sub.R and this differential pressure can form the basis of the evaluation of the control value U for the valve 16.
(41) In the variant of the heat transfer system according to FIG. 7e, in contrast to the embodiment according to FIG. 7d, a differential pressure sensor 56 is provided, which directly detects the differential pressure between the entry side and exit side of the valve 16 and leads this differential pressure Dp.sub.S to the control device 52, wherein this control device as described takes this pressure difference into account for determining the control signal U for the valve 16.
(42) The embodiment according to FIG. 7f differs from the embodiment according to FIG. 7e in that a supply pump 48 setting the supply flow q.sub.S is arranged in the supply conduit 12 instead of a valve 16. The supply pump 48 simultaneously serves a as temperature sensor for detecting the supply temperature T.sub.S and issues this supply temperature T.sub.S to the control device 52. Moreover, with this embodiment example, one makes do without the check valve 18 and also without the flowmeter 54. Instead, the load flow q.sub.L again is here determined by the load pump 20 and issued to the control device 52. The control device 52 in the manner described above determines the necessary speed n for the supply pump 48 on the basis of the determined variables as well as the desired entry-side load temperature T.sub.ref.
(43) The previously described feedforward control has the advantage that a more rapid regulation can be effected since a more rapid adaptation of the load flow q.sub.L is possible, in order to bring the entry-side load temperature T.sub.L as quickly as possible to the desired entry-side load temperature T.sub.ref.
(44) Additionally to this feedforward control, which was described schematically by way of FIG. 3, as is shown in FIG. 8, an additional feedback control for the entry-side load temperature T.sub.L can be provided. As is shown in FIG. 8, an additional feedback regulator is provided for this, to which the desired entry-side load temperature T.sub.RS as well as the actual entry-side load temperature T.sub.L are led as input variables. The output signal of this feedback regulator or controller 62 is added in the adder 64 to the output signal of the feed-forward evaluation 38 and then led to the multiplier 46, via which the desired supply flow q.sub.S is then determined in the manner described above. A valve 16 for the regulation of the supply flow q.sub.S is also used in this example. It is to be understood that the use of a feedback regulator 62 could however also be accordingly applied with a supply pump 48 in a manner complementing the control shown in FIG. 4.
(45) Moreover, the problem of delays occurring in the regulation can arise due to a spatial distance between the point at which the returning fluid and the fluid form the supply conduit are mixed, i.e. the mixing point 14 and the point at which the entry-side load temperature T.sub.L is determined via the temperature sensor 22. Accordingly, with the use of a heat exchanger, the distance between the heat exchanger 28 and the temperature sensor 22 can be very large. A transport delay in the regulation occurs on account of this. Additional correction factors can be applied in order to compensate this. Moreover, this transport delay is however also dependent on the load flow q.sub.L, i.e. with a high load flow q.sub.L the fluid mixed at the mixing point 14 or heated in the heat exchanger 28 reaches the temperature sensor 22 more rapidly than with a low delivery flow q.sub.L. As is shown in FIG. 9, an adaptation device 66 can be applied for this, as a supplement to the control or regulation shown in FIG. 8. Amid the application of two scaling factors A.sub.I and A.sub.P as well as two functions f.sub.I and f.sub.P, a proportional amplification factor K.sub.P as well as an integral amplification factor K.sub.I which are led to the feedback regulator 62 can be formed in the adaptation device 66 on the basis of the detected load flow q.sub.L. There, the amplification factors K.sub.I and K.sub.P form amplification factors of a PI-regulator which is used there, by which means the transport delay is compensated.
(46) FIG. 10 shows a variant of the control according to FIG. 9. The adaptation device 66 and the feedback regulator 62 as well as the feedforward evaluation 38 correspond to the preceding description, but the amplification factor evaluation 40 is constructed somewhat differently. The output signal of the subtractor 42 is led to an inverter 68. The load flow q.sub.L is multiplied in a multiplier 70 directly by the output signal of the feedforward evaluation 38 and then led to the adder 72 for the addition to the output signal of the feedback regulator 62. The output signal of the adder 72 is led to the multiplier 46 where it is multiplied by the output signal of the inverter 68 for determining the desired supply flow q.sub.S. The evaluation of the control variable U for the valve 16 is then effected in the manner described above.
(47) FIG. 11 shows a variant of the control according to FIG. 6 amid the use of a feedback regulator 62 and an adaptation device 66, as has been described previously. With this, the output signal of the multiplier 46, as has been described by way of FIG. 6, is added to the output signal of the feedback regulator 62 in an adder 64. Subsequently, in contrast to the embodiment example according to FIG. 6, as has been described by way of FIG. 4, the speed n for a supply pump 48 is determined on the basis of the desired supply flow q.sub.S determined at the adder 64.
(48) It is to be understood that if, in the preceding embodiment examples, certain functions have been described in the context of a supply pump 48, this can also be realized in a corresponding manner also with a supply valve 16. Accordingly, functions which have only been described in the context of the supply valve 16 can also be realized in a corresponding manner with a supply pump 48. A difference merely lies in the evaluation of the speed n as well as the control variable U on the basis of the determined supply flow q.sub.S.
(49) Moreover, it is to be understood that all control and regulation steps as have been described beforehand, preferably take place in the shown control device 52. This thus represents an electronic control device for the entire heat transfer system.
(50) While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
APPENDIX
List of Reference Numerals
(51) 2 load circuit 4 supply 6 mixing conduit 8 outlet 10 entry 12 supply conduit 14 mixing point 16, 16, 16 valve or supply valve 18 check valve 20 load pump 22, 24, 26, 26 temperature sensors 28 heat exchanger 30 first flow path 32 return 34 second flow path 36 temperature sensor 38, 38 feedforward evaluation 40, 40, 40 amplification factor evaluation 42 subtractor 44 divider 46 multiplier 48 supply pump 50 flow regulator 52 control device 54 flowmeter 56, 56, 56 differential pressure sensor 58, 60 pressure sensors 62 feedback regulator 64 adder 66 adaptation device 68 inverter 70 multiplier 72 adder 74 adder T.sub.RS desired entry-side load temperature T.sub.L entry-side load temperature T.sub.RL exit-side load temperature T.sub.S supply temperature T.sub.RS exit-side temperature of the supply circuit T.sub.R exit temperature, corresponds to T.sub.RS with the mixer and T.sub.RL with the heat exchanger q.sub.L load flow q.sub.S supply flow Dp.sub.S differential pressure n speed U control variable K.sub.P, K.sub.I constants A.sub.I, A.sub.P scaling factor K.sub.qn signal dependent on the flow resistance
