DE3001550A1 - Solar collector heat source control - has changeover valve with actuating command derived from temp. difference between collector and consumer and time source - Google Patents

Abstract

The solar energy collector is intended to supply heat energy to a consumer appliance in a system of several such appliances operated at different temperatures. It uses a change-over valve between the collector and appliance. The change-over command for the system control is derived from the temperature difference magnitude between the collector and appliance, preferably as a time-temperature integral. The control device uses temperature sensors both in the solar collector and the two storage vessels, coupled by separate lines to measured value converters, behind which are connected integration. The latter outputs are supplied to comparators, where the integrals are processed. Behind the comparators may be connected evaluation switches. A clock pulse generator may be coupled to the measured value converters and to a change-over switch.

Description

. .;.: 3Q01550

"Joh. *" Va "illant GmbH u. Co DE 829 -

t 6. Ot 8S

Control method for a control device of a solar collector heat source

The present invention relates to a control method for a control device of a solar collector heat source and to the design of the control device for carrying out the method according to the preamble of the main claim or the independent claim b

From DE-OS 28 OO 173 is a plant for the recovery of Solar energy has become known for heating water, in which a solar collector is controlled via valves

130030/0388

RAn

device both on a "Speiche'r aXs" as well as on another Storage can be switched, with the hot water storage in an underlying preheater and one with this connected overhead reheater is divided. The individual storage tanks are switched on by a switching valve the solar collector is switched on, the switching of the valve being temperature-dependent. The aim is to achieve that depending on the existing temperature level in the solar collector, one or the other heat storage with the solar collector is connected, so that a utilization of relatively small amounts of heat in the solar collector is possible. So serve the so-called preheater a preheating, for example of domestic water, whose final heating for example by a Additional heating is achieved.

Based on this prior art, the present invention is based on the object when charging the consumer or storage tank with the lower temperature level then switch to the storage tank with the higher temperature level, if both, a sufficient temperature difference between the temperature level of the at a higher level and the direction of movement of the temperature gradient in the solar collector is positive is. It is then to be expected that even if the solar collector is connected to the storage tank with the higher Temperature level a sufficient temperature gradient over time maintained between solar collector and storage tank remains, so that heat can be supplied to this memory.

130030/0388

_BATH ORIGINAL

A method that solves this problem is given in the characterizing part of the main claim.

The resulting technical port step is in a greater utilization of the heat output that can be given off by the solar collector to see.

The subject of the subclaims are further developments of the Process or devices that are useful for carrying out this process.

With reference to the figures one to seven of the drawings are exemplary embodiments of the invention or control diagrams, which are described below:

Show it

Figure one is a schematic representation of the circuit of the solar collector,

Figure two a variant of the circuit according to Figure one,

Figure three shows the schematic principles of the control device and

the figures four to seven characteristics of the control

130030/0386 BiAD ORIGINAL

- χ- 3

characteristic of the control device. "

In all seven figures, denote the same reference numerals respectively the same details.

A heat absorber 1 in the form of a radiation source from a radiation source 2 (sun) or heat convection appealing heat exchanger - is usually designed as a solar collector at its flow 3 with a heat sensor 4 and a Drain valve 5 provided. From the flow 3 there is a flow line 6, which is secured with a pressure relief valve 7. The flow line 6 leads to a 3-way switch valve 8, one output of which via a line 9 to a return line 10 leads to the return flow 11 of the solar collector, the return line 10 being connected to a circulation pump 12 is. An expansion vessel 13 is connected to the return line 10 via a branch line 14.

The second line 15 outgoing from the 3-way switch valve leads to another 3-way valve 16, which depending on its position, the flow 3 of the solar collector on a storage flow line 17 or another storage supply line 18 switches. The storage supply line 17 is connected to a first Consumers in the form of a memory 19 with a relative connected high target temperature level, which the water is discharged via a storage return line 20 again. The storage flow line 18, on the other hand, is via a heat exchanger: 21 to a second consumer in the form of another

130030/038 6

-JBT- If

Storage tank 22 connected with a relatively low target temperature level, the associated storage return line 23 forms with the storage return line 20 a junction 24, from which the return line 10 is interposed a check valve 25 goes off between the confluence the line 9 and the junction 24 in. The return line 10 is switched on.

The memory 19 is, for example, one Domestic hot water storage tank via an internal pipe coil heat exchanger 26 can be discharged, to which a cold water mains line 27 is connected and which has a tap water supply line 28, into which a reheater 29 is inserted, is connected to the actual tap 30. To the line 27 or behind the reheater you could also connect central heating.

The second memory 22, which is operated at a relatively low temperature level, is a swimming pool. The memory 19 has priority over the memory 22 insofar as that at a sufficiently high temperature level In the solar collector 1, the memory 19 has priority over the memory 22.

Both inside the memory 19 and inside the memory 22 are each a temperature sensor 31 or 32 are provided which are connected to a control device 35 via measuring lines 33 and 34, respectively. Likewise is

130030/0386

BATH ORIGINAL

'-jr- ΛΑ

the temperature sensor 4 via a measuring line 36 to the control device 35 connected. Control lines 37 and 38 of the control device lead to the actuation devices of both 3-way switching valves 8 and 16, and a control line 39 leads from the line 38 to the drive motor of the pump 12.

In the exemplary embodiment according to FIG. Two, the two stores 19 and 22 are related to the solar collector circuit Connected to one another via lines 40 and 41 and placed one above the other. The memory 19 is also located here both the actual value and the setpoint value at a higher temperature level than the memory 22, the memory content (Solar collector circular volume) of the preferred memory 19 is much smaller than that of the long-term memory 22nd

The three temperature sensors 4, 31 and 32 are three as shown in FIG Part of the control device 35 · These three temperature sensors are resistors with negative temperature coefficients formed, that is, their resistance value decreases with increasing temperature. When applied with a constant Voltage thus drops the voltage value dropping across them with increasing temperature, so that corresponding measurement signals on lines 33 »34 and 36, which are connected to a Moii- ■ value converter 42 are connected, which also performs limiter functions. Lines branch off from lines 33 and 36 43 and 44, which lead to a further transducer with a limiter function 45 lead.

■ 130030/0386 BAD ORIGINAL

A line 46 leads from the transducer 45 to an integrator 47, from which a line 48 leads to a comparator 49.

Likewise, a line 50 leads from the transducer 45 to an integrator 51, which is connected to another via a line 52 Input of the comparator 49 is connected. An output line 53 of the comparator leads to an evaluation circuit 54 with 3 outputs 55, 56 and 57 ', which are a power switch 58 is switched on.

A first output line 59 leads from the transducer 42 Via an integrator 60 to a line 61 which is connected to an input of a further comparator 62. Another output line 63 of the transducer 42 leads to a further integrator 64, to whose output a line 65 and a further line 66 are connected. The line 66 leads to a second input of the comparator 62. The comparator 62 is via a line 67 a further evaluation circuit 68 connected downstream. Three lines 69, 70 and 71 also lead from evaluation circuit 68 to Circuit breaker 58.

The line 65 leads to a changeover switch 72. An output of the changeover switch 72 is via a line 73 in which a memory 74 is switched on, connected to a further comparator 76. A second output of the switch 72 is via a Line 75 connected to the comparator 76, via an output line 77 with

130030/0388

ORIGINAL

- / - Al

a third evaluation circuit 78 is connected: is. This evaluation circuit again has three output lines 79, 80 and 81, which are like the output lines of the "other two" Evaluation circuits in turn with the circuit breaker 58 are connected.

The integrators 47 »51» 60 and 64 can all be designed in the same way they basically consist of RC elements. as well the comparators 49, 62 and 76 can be designed identically, they are preferably connected as Schmidt triggers. The evaluation circuits 54, 68 and 78 can also be the same be designed, they also represent threshold switches. The power switch 58 only has an amplifying function.

The control device 35 is assigned a clock generator 82, which is able to deliver voltage pulses of different and adjustable time intervals on different outputs. Such timing signals are sent once via line 83 to changeover switch 72 and via line 84 to the circuit breaker 58, assigned to both transducers via lines 85 and 86.

The circuit breaker 58 has output lines 87, 88 and 89 which lead to coils of relays 90, 91 and 92. The Relay is assigned a pair of normally open contacts, the is operated jointly via an adjusting rod 93, 94 and 95.

A line 96 leads from a network terminal R to a line junction 97, which leads to the base points 98 and 99 of the first

130030/0386

ORIGINAL

Pairs of make contacts of relay QO ge-f-ühr ^{: j} o si-lid · - The two contacts 100 and 101 can be switched to lines 102 or 103 depending on the position of the relay, with line 102 at a base point 104 of the pair of make contacts of the relay 91 is performed. The line 38 'branches off from the line 102; when voltage is applied to this line, the three-way switch valve 8 is switched so that the supply line 6 is connected to the line 15.

The line 37 'is the three-way valve when voltage is applied 16 switches so that the line 15 with the storage flow line 18 is connected, is led to a base point 105 dea normally open contact pair of the relay 91. The two Contacts 106 and 107 of this relay are on contact pieces connected, which are connected to one another via a line 108. This line is in turn via a line 109 the network phase R is connected, this line leads to a connecting line 110, to which in turn two base points 111 and 112 of two contacts 113 and 114 of the normally open contact pair are connected, which is assigned to the relay 92. The corresponding contact pieces of contacts 113 and 1.14 are connected to the lines 38 and 37, when voltage is applied to these lines, the line 37 causes a Adjustment of the three-way valve 16 in such a way that the line 15 is connected to the storage flow line 17, or in the case of the line 38, that the three-way switch valve 8 connects the flow line 6 to the line 9. The line 103 is connected to the line 37.

- 10 -

130030/0386

^A '** - ■■■

It is assumed that the actuating motors or Switching solenoids of the three-way switch valve 8 or the three-way valve 16 connected to MP at the other end.

The circuit just described with reference to Figures one and two according to Figure three has the following function:

All relays 90, 91 and 92 are de-energized, the contacts are in the position shown. The pump is disconnected from the mains terminal via the line 39 because the contact 113 is open. The three-way switch valve 8 is switched so that the line 6 is connected to the line 9, the three-way valve 16 so that the line 15 is connected to the line 18. It is also assumed that the temperature that the temperature sensor 4 measures at the solar collector flow 3 is lower than the temperatures that the sensors 31 and 32 measure.

If the solar collector flow temperature now rises, see above the circuit remains idle as long as the temperature of the temperature sensor 4 does not exceed the temperature, on which the memory 22 is located and that of the temperature sensor 32 is measured. If the temperature measured by temperature sensor 4 exceeds this temperature value, in this way the corresponding measured values which are present on lines 34 and 36 are forwarded by measuring transducer 42. The measured values are converted to the integrators 60 and

130030/0388 ~ ¹¹ ~

BATH ORIGINAL

- ^:: . :: 3DG1550

64, where the respective integrals are formed over time will. Since one can assume that the integral of the temperature over time for a short time due to the signals of the clock 82 successive measurements in the memory 22 remains constant, the corresponding integral in the solar collector flow However, if there is an increasing tendency for the individual measurements, the corresponding tendencies are determined by the comparators 62 and 76 noted. The successive measurements in the integrators 60 and 64 are made by the timing pulses on lines 85 and 86 caused. It is a question of expediency how quickly and at what intervals in a row the measurements are made. The respective last measurement result of the integrator 64 is transmitted via the switch 72 in each case supplied to the memory 74, so that the comparator 76 compares the new integral values with the old, last integral value can compare. When a new integral value appears, the memory is erased, along with the last valid integral is saved there. Due to the positive trend of the individual consecutive integral values causes the evaluation circuit 78 to carry out further measuring processes with the aim of recognizing whether the temperature continues to rise at the solar collector flow increases so far that even the memory 19 can be charged. Loading the memory 22 would be possible at this point in time.

These relationships can be clearly seen from FIG. Starting at time t = 0, at which the temperature of the Solar collector flow is lower than the temperatures

- 12 -

130030/0388

: Λ * BAD ORIGINAL

- Vt - ^f

which are present in both memories, the temp in the solar collector flow according to curve 115 high. The temperature value of the memory 22 is at a level 116, the temperature value of the memory 19 is at a temperature value 117 · Dsr point of intersection between curves 115 and 116 with 118, represents the case that the temperature value of the Solar collector flow is equal to the temperature value of the storage tank 22. If the temperature value of the solar collector flow increases The investigation of the current integral values just described takes place above this temperature value. Assuming that the value of curve 115 reaches the level of curve 117, the point of intersection 119 is reached. When this point of intersection is exceeded, the evaluation switch 54 switches through because the temperature value is exceeded in the solar collector flow or in the memory 19 via the lines 43 and 44 also the transducer 45 was communicated, the these signals processed and via the comparator 49 and the line 53 had communicated this evaluation switch. Of the Circuit breaker 58 is excited and switches the relay 90 so that the two contacts 100 and 101 close. Thus, line phase R is both on the line via line 96 38 * as well as on line 37 · This means that the three-way switch valve 8 is switched so that the flow line 6 to the line 15 and this via the three-way valve 16 is connected to the storage flow line 17. Thus loads the solar collector 1 on the memory 19 with the higher temperature level. The beginning of this state is through the corner of the curve 120 defined, the kinked curve 121 is

- 13 -

130 030/0386 ! * ■ "■■: ■: ■>? ·:« - ^Λ? BAD ORIGINAL '

is enough, due to the load of the closing-holiday storage the solar collector can no longer increase its temperature as much. The curve 121 could continue to rise, and with it the temperature level in the memory 19 could be increased until the maximum memory limit value is reached. A further charging of the memory is carried out via a limiter setpoint generator 122, which is assigned to the measuring transducer 45 19 prevents, the same can happen via a limiter 123 which is assigned to the transducer 42. Is the limit of the memory 119 is reached, the solar collector flow 6 to the memory 22 with the lower temperature level forcibly switched, a corresponding control command results from line 124 · In this case, the memory 22 is heated up by solar collector 1 until it reaches its storage limit value, set on limit value transmitter 123, is reached. Then the solar collector switches off.

In the case of FIG. Five, a maximum point 125 results for example, in that when loading the memory 19 with the higher temperature level suddenly decreases the solar radiation. The consequence of this is a falling temperature value on the line 36 or 44 · This leads to the integrators 47 and 64 register integral values of decreasing size. Since these values correspond to the temperature values of sensor 31 are compared in the memory 19 in the comparator 49, interrupts the evaluation switch 54, the further charging of the memory 19 by de-energizing the relay 90. Thus, all Relays 90, 91 and 92 de-energized, the corresponding contacts

- 14 -

130030/0386

ORIGINAL

opened again.

However, since the temperature value on the line 36 is greater than on the line 34, corresponding signals are measured by the integrators 60 and 64. An ongoing, cyclical comparison of the integral values, however, shows the evaluation switches 68 and 78 that the integral value of the solar collector flow falls, namely according to curve 126 '. Thus, there is no prospect that the temperature value a. ^m xf of the line 36, since it comes from higher values, could be sufficient to load the memory 19 again. If the comparison in the comparator 62 shows that the integral values of the integrators 60 and 64 are so positive that the value of the integrator 64 is greater than that of the integrator 60, but on the other hand the value of the integrator 64 has a falling tendency, a corresponding signal is output Via the line 66 to the comparator 62. The evaluation switch 68 responds to this Pail and actuates the relay 91 via the power switch 58, which leads to the contacts 106 and 107 closing.

The evaluation switch 78 only transmits a signal if the value between the integrators 64 and 60 is the same is positive, but in addition the value of the integral from the integrator 64 has an increasing tendency.

Thus, R is via the line 109 and the contacts of the relay 91 once on the line 37 'and the second on the line jof. This means that the solar collector flow

- 15 -

130030/0386

BATH ORIGINAL

6 about the three ^ -V / ege-Ümsclialtve-nti-l 8 to line 15 and this in turn is switched to line 18 via the corresponding three-way valve 16 is what leads to a charging of the memory 22 with the lower temperature level. The corresponding switching point can be seen through the kink point 127, through the connected When the memory 22 is loaded, the curve 126 drops more rapidly. Without the connection of the memory 22, the curve would follow of curve 126 'run with a significantly flatter characteristic.

If the falling curve 126 reaches the point 128, the Temperature signals on lines 36 and 33 are the same, evaluation switch 68 locks, relay 91 opens, all relay contacts are de-energized, the circuit goes to sleep and separates the solar collector from both storage tanks.

According to the curve 129, the memory 22, based on the temperature level according to curve 116 between points 130 and 128 loaded. The hatched area I3I means the Heat gain. The diagram in FIG. Four describes the prior art, which consists in switching off the memory not to switch on the other storage tank with the higher temperature level.

At the moment when the solar collector is switched off from the store 22, it remains at an elevated position compared to curve 116 Temperature level according to curve 132.

The hatched area 133 means the temperature gain

- 16 130030/038 &

BATH ORIGINAL

■. -At -

in the memory 19 obtained / in eggern · man - -erf-indü-Rgs according to the temperature readings between the solar collector flow, compares the first memory and the second memory in time cycles until it is ensured that with very high probability of the solar collector reaching the temperature level of the memory 19 according to the curve 117 and will exceed. ·

The gain made by the invention is through the comparison between the figures four - representing the state of the Technology means - and five can be seen. Due to the priority circuit that the solar collector is as close as possible to the Memory mil; the higher temperature level is switched, the solar collector 1 first loads the associated memory. If the temperature in the solar collector flow falls, this If memory is no longer loaded, there is no switchover instead of the storage tank with the low temperature level, instead of switching off the solar collector. The profit of the invention is thus in the area 131

Under "the assumption that the solar collector with his Temperature value /, was the memory 22 with the lower temperature value exceeds, but for some reason does not reach a temperature value that a loading of the memory With the higher temperature level made possible, there are conditions according to Figures six and seven, with the Figure 6 represents the prior art.

- 17 -

130030/0388

BATH ORIGINAL

Since in the prior art with a VöTrängsctialtting "on" the Storage with the higher temperature value is used, the temperature value of the solar collector increases, measured by the Sensor 4, based on curve 134, exceeds at point 135 the temperature value of memory 22 with the lower one Temperature level according to curve 136. At point 137, the tilts Temperature curve of the solar collector from, for example by shading. The temperature curve then falls at a point 138 of the solar collector according to the curve 139 again. Due to the priority switching, neither of the two Memory loaded.

According to the invention according to FIG. Seven, the same conditions initially occur:

The curve 134 rises to the intersection point 135 and in this case exceeds the level I36 of the memory 22. After exceeding of the level at point 135, the previously described evaluation of the integral takes place in the integrators 60 and 64. From point 137 the measured value of the integrator 64 is positive and greater than the measured value of the integrator 60, only the value of the integrator 64 does not increase any more because the curve

140 according to a specification no longer rises and the temperature level

141 of the memory 19 with the higher temperature level is not achieved. As well as this state via the comparison of the integral values of the integrators 60 and 64 controlled by the clock generator 82 registered, the comparator 62 is acted upon at the time 142 via the lines 61 and 66. The evaluation switch 68 switches the circuit breaker 58

- 18 -

130 030/0386

"iAD ORIGINAL

- te- -

Relay 91, what about closing the contacts "105 uhd-'iO? leads. The memory 22 with the lower temperature level is loaded. The. Charging takes place as long as after When curve 140 bends at point 138, the temperature value of the Solar collector according to curve 139 is greater than the respective charge level of storage 22 according to curve 143 · at the intersection “of both curves 144, the values of integrators 60 and 64” become the same, which leads to the contacts of relay 91 opening via the evaluation switch 68 leads. The memory 22 remains at a temperature level according to the curve 145 · the hatched Area 146 represents the charge gain in memory 22 compared to the prior art.

The clock generator 82 then regularly causes a comparison of the values of the integrators 60, 64 or 47, 51 »if the temperature value larger in the solar collector on line 36 is the temperature value of one of the two memories, measured by sensors 31 and 32 and present on the lines 33, 34 or 43, 44.

In the exemplary embodiment according to FIG. Two, the memory is 19 with the higher temperature setpoint is much smaller in its volume than the storage tank 22. It can happen that that the memory 19 is discharged by connecting the consumer 30 and is at a temperature level, which is lower than that of the storage unit 22. The storage unit is now charged via the lines 40 and 41 19 via the memory 22 instead. This case can certainly occur when the sun is not shining.

- 19 -

130030/0386 ......... "BAD ORIGINAL /

It can be useful to arrange a temperature sensor 147 in the solar collector flow line 6, which has a contact 148 actuated, which lies in the course of the line 38. Thus, the three-way switch valve 8 can only then feed the solar collector 6 switch to line 15 when the value of the solar collector flow measured by the temperature sensor 147 is greater than the temperature values of both memory 19 and 22. This measure is intended to prevent that originally warm water in the solar collector "when passing the under certain circumstances very long line 6 does not cool below the temperature value "of both stores. The three-way switch valve 8 thus switches when the temperature falls below the value measured by sensor 147, line 6 to line 9.

130030/0386

Claims (16)

Joh.Vaillant GmbH u.Co DE 829 1 B. Ol 80 Expectations Control method for a control device of a solar collector heat source for feeding a consumer of several that are operated at different temperature levels and over with a switching valve whose position depends on the temperature difference between the solar collector flow and consumer depends, provided lines can be connected to the solar collector, characterized that as a switching command for the control device, the size of the temperature difference between the solar collector flow and the consumers 130030/0388 BATH ORIGINAL and the time course of the difference (gradient) is provided. 2. Control method according to claim 1, characterized in that that the integral of the temperature of the solar collector flow over time is provided as a switching command is. 3. Control method according to claim 1 or 2, characterized characterized that in the case of a positive temperature difference between solar collector flow and consumer and a positive gradient or an increasing integral the control device switches the solar collector flow to the consumer with the higher temperature level. 4 · Control method according to one of Claims 1 to 3> characterized in that in the case of a positive temperature gradient or increasing Integrals with positive temperature difference between solar collector flow and consumer the solar collector is short-circuited by the control device and after a delay time has elapsed - a switch is made to the consumer with the higher temperature level. 5 · Control device for carrying out a method according to one of Claims 1 to 4> characterized by 130030/038 8 BATH ORIGINAL Saving (.19, 22) temperature sensors (4, 31, 32) are provided, which via lines (33, 36 τ 43, 44) transducers (42, 45) are fed, which integrators (47, 51, 60, 64) are connected downstream. 6. - Control device according to claim 4, characterized in that the integration values of the integrators (47 * 51 "or 60, 64) at inputs one each Comparator · (49) are performed. 7. Device according to claim 5 or 6, characterized in that that in the comparator in each case the temperature integrals over the time of both the solar collector flow as well as each of a memory are compared with each other. 8. Control device according to one of claims 5 to 7, characterized in that the comparators (49, 62, 76) evaluation switches (54, 68, 78) are connected downstream. . " 9- control device according to one of claims 5 to 8, characterized in that a clock generator is provided is connected to the output lines (85, 86, 83). Transducers (45, 42) and a switch (72) is connected. 130030/0 38 θ BATH ORIGINAL 10. Control device according to Ansp'rucil 9> * "marked by, that the changeover switch (72) with the associated comparator (76) both directly via a line (75) and via a further line (73) into which a memory (74) is connected is. 11. Control device according to claim 10, characterized in that the memory (74) is the last The integral of the solar collector flow is saved and when a new integral value occurs in the Solar collector flow deletes the old integral value. 12. Control device according to claim 11, characterized in that the memory (74) with the clock generator (82) is connected via a line (83, 73). 13 · Control device according to one of Claims 1 to 12, characterized in that each comparator (49, 62, 76) has an evaluation circuit (54, 68, 78) is assigned, the output of which is switched to a relay (90, 91, 92) via a circuit breaker (58) is. 14 · Control device according to claim 13, characterized in that that the evaluation circuit (54) switches through when there is a positive temperature difference between the solar collector and the storage tank with the higher temperature 130030/0386 WHEEL ORIGINAL level (19) 15 · Control device according to claim 13, characterized in that that the evaluation circuit (68) switches through when there is a positive temperature difference between the Solar collector flow (6) and the storage tank with the lower temperature level (22) "with falling Value of the integral of the solar collector flow. 16. Control device according to claim 13 »characterized in that that the evaluation circuit (78) switches through "in the event of a positive temperature difference between the solar collector flow (6) and the memory with the lower temperature level (22) but decreasing integral of the solar collector flow 13 0030/0388