DE102009022765A1 - Solar system for solar heating support of heating or cooling system, comprises solar collector and heat transfer fluid, where circulation of heat transfer fluid is switchable through solar collector by two valves - Google Patents

Abstract

The solar system (A) comprises a solar collector (1) and a heat transfer fluid, where circulation of the heat transfer fluid is switchable through the solar collector by two valves (2,2a). Two inlets and two outlets are formed between a hydraulic switch point (5), which is a mixing chamber. A pressure maintenance pump (10) is arranged between a station (8) and an integration module (18).

Description

The Invention relates to a solar system, as a solar support for a heating or cooling system, but especially as solar heating support is suitable.

These Solar system contains in a known manner a solar collector, in a filled with a heat transfer fluid Solar circuit is arranged. Such solar circuits are in the prior art via a heat exchanger led, in or at one with another heat transfer medium filled heat storage is arranged. The heat transfer fluid of the solar collector cycle is usually with a Antifreeze provided so that the heat transfer medium does not freeze at low temperatures. At particularly high irradiation temperatures of the solar collector there is a risk that the heat transfer medium because of the relatively low, hydrostatically determined operating pressure begins to boil or goes into its vapor form. It also exists the danger that the antifreeze at high temperatures chemically decomposed.

at another well-known solar system by the Rotex Systems GmbH is the mentioned, in the heat exchanger integrated memory designed so that the warmed up Solar water flows from a manifold into the heat accumulator and there with this heat transfer medium the heat supply forms. At the bottom of the heat storage is the solar water pumped and fed back to the solar collector. The heat for service water and heating will be off the heat accumulator via submerged pipe spirals, which act as a heat exchanger, taken.

A disadvantage of the relevant prior art is therefore not only that the solar circuit has no regular, ie beyond the mere hydrostatic pressure in addition operating pressure with a pressure maintenance, but also that a heat exchanger for heating connection to the solar circuit is required. Furthermore, the use of antifreeze in the solar circuit is disadvantageous because this material can harden under high heat and damage the valves, pumps and pipes. A further disadvantage is that the degassing / venting in the solar circuit either completely absent or must be accomplished by a standalone station, which is separated from one at the same, the station of the heating circuit through the heat exchanger. The prior art has not recognized that one can use such a station, which provides a variety of functions, with a suitable adaptation to the system for the heating circuit and the solar circuit. The use of such a station only for a heating or cooling circuit is from the writings DE 8228065 U1 . DE 3237023A1 . DE 3716396 A1 . DE 19705741 C1 . EP 108 266 A2 and EP 187 683 B1 (Inventor and applicant each amber) become known.

The The object of the invention is known from the heating circuit itself Pressure maintenance, degassing etc. so to change and expand, that they also simultaneously in the heat transfer fluid of the solar cycle becomes effective.

The Solution lies in a solar system according to claim 1. The solar system has first - as usual - one Solar collector in the circuit of a heat transfer fluid lies. In contrast to the prior art, in which a pressureless Medium in such a solar cycle through a heat exchanger in a heat storage or by a buffer memory with other heat exchangers, namely for the purpose of heat dissipation, closes the solar circuit of the invention over a so-called hydraulic switch, that is via a mixing chamber with at least two inlets and two expirations. Furthermore, it is essential that this cycle of the heat transfer fluid is switchable by the solar collector by means of two valves, to no more about emptying and ventilation pipes to the mixing chamber, but to lead to a special station. This station is responsible for various functions, at least for the functions pressure maintenance, expansion, Degassing / deaeration of the heat transfer fluid, and especially also for the admission a reduction volume and for the air supply to appropriate ventilation of the solar collector.

Further Properties of the solar system according to the invention are apparent from the dependent claims.

The named station can not only be connected to the solar circuit via the emptying and ventilation pipes, but also connected to the solar system via an integration module which is located in the main flow of the unconverted solar heat transfer fluid. A pitot tube branches off from the main stream a partial flow, which is freed in the station of gas bubbles (venting) and can be additionally freed of dissolved gases (degassing). The partial flow is fed back to the integration module and thus to the solar heat transfer fluid circuit by means of a pressure maintenance pump. This pressure maintenance pump will periodically turn on at a pre-programmable distance of several minutes to insure degassing and venting, or it will turn on pressure dependent to maintain the operating pressure in the solar system. In the case of rapid degassing, the pressure maintenance pump can also run for a longer period of time. Such functions are known per se for heating circuits in which such a station is integrated (cf. DE 8228065 U1 etc.).

The Switching the pressure maintenance pump can according to the invention electronically instead of manually programmed as another part of an electronic control be required anyway for the valves of the solar system is. In this way, the operating pressure goes to the highest point the solar system (and in the entire system) over the previous, used in the prior art, pure hydrostatic pressure addition, to an evaporation of the heat transfer fluid at counteract high temperatures by increasing the pressure. This expands the thermally usable area of the solar system. If this operating pressure regulated by the pressure holding pump is in the solar system should not be enough for this purpose, finds for safety's sake, the emptying invention and ventilation by switching the emptying and switching valves instead of. In contrast, the solar panel returns to a normal, medium temperature range back, and calls for a heating system or a buffer tank Heat on, so does the solar panel by the controller again filled with the medium.

One spring-loaded pressure relief valve between the station and the integration module opens for the medium into the station in an operating condition in which a preset operating pressure is exceeded. This part of the pressure regulation represents one through the regular Pressure maintenance achieved safety measure, which is the Solar system first, continue working at high temperatures allowed before for reasons of overheating is emptied.

At the lower end of the emptying tube is a check valve, which is an intrusion of air from the air volume of the station prevented in the solar panel and that just emptying the Heat transfer fluid from the collector into the station allowed.

If the amount of heat transfer fluid as a whole too far should have sunk, so is one installed in the station Fresh water supply capable of recovering the missing volume to complete. A system separation prevents this at this point heat transfer fluid in the fresh water line can occur.

The station includes in a known manner a substantially airtight pressure vessel (see. DE 8228065 U1 etc.). Although this airtight pressure vessel separates itself and the entire system from the atmosphere, but can still be called because of the pressure conditions in the pressure vessel as essentially "pressure-less". The pressure maintenance valve and the pressure maintenance pump cause namely only small deviations from the atmospheric pressure in the air-tight pressure vessel itself, so that the slightly fluctuating pressure level in the container is significantly below the desired operating pressure in the solar circuit.

One An essential advantage of the invention is that the heat transfer fluid, be it water or be it water vapor or another fluid, in any case contains no antifreeze. This will be unfavorable thermal changes (speak one Resinification) of the antifreeze avoided, but without that Heat transfer fluid freezes during frost. Because at too low temperatures, the heat transfer fluid also from the solar panel to a certain level Drained draining, as at too high temperatures too. Only when the solar collector in a normal usable temperature range returns, the solar panel is replenished. For this purpose, the pressure maintenance pump promotes the heat transfer fluid from the supply of the station pressure vessel into the solar collector and the air in the collector is simultaneously over the Check valve displaced in the air supply of the station.

Of the Pressure vessel in the station will be compared to previous ones Applications of the station, which were in the heating circuit, increased and initially contains a sufficient storage volume at heat transfer fluid. Then that's over sufficient air or gas cushion located in this stock Room for the so-called expansion volume of the heat transfer fluid. For the thermal expansion of the fluid must be here at this application takes into account the total volume of fluid be used in the solar system, in the heating system and in the hydraulic switch and / or optionally in the heat accumulator uniform and is included undivided. The expansion volume is good Degassing / venting of the medium, by the way, lower, as if gases are contained therein; the two functions expansion and Degassing is based on each other. After all the air cushion must be large enough to the inventive Reduction volume of the solar system up to a predefinable emptying level record and the corresponding displaced air reversed to spend in the solar panel.

To the Solar circuit owns its own circulation pump to the fluid flows of the solar circuit on the one hand and the heating circuit on the other hand in the hydraulic mixing chamber, called hydraulic Soft or formed as a heat storage chamber in the heat storage can be decoupled. The solar circuit as such will be in the Principle completed by a mixing chamber, which consists of a hydraulic switch or from the (in this case not equipped with a heat exchanger) Heat storage or can consist of both.

The invention will be described below with reference to Patent drawing 1 , which shows the schematic diagram of a solar system according to the invention without antifreeze and without heat exchanger, explained in more detail. The only figure shows a solar collector 1 in the area of a solar system A. The area of the heating system B is initially disregarded.

A cycle of solar heat transfer fluid closes (from the solar collector 1 from) via a three-way valve 2a in a different operating position than drain and diverter valve 2a acts. Subsequently, the volume flow of the heat transfer fluid, which may be water or another suitable fluid flows through a hydraulic switch 5 , The hydraulic switch 5 has at least one inlet and one outlet for the solar heat transfer fluid and at least one inlet and a drain for another volume flow of the same heat transfer fluid. It is important that this common heat transfer fluid in the mixing chamber of the hydraulic switch 5 can mix and operate uniformly (ie for the two coupled volume flows) without antifreeze.

The solar circuit volume flow continues via an integration module 18 passed, through which a partial flow into a station 8th is directed. The station 8th will be described below.

The in the integration module 18 reunited partial flows are then through a circulation pump 11 promoted in the solar circuit. The solar circuit closes by an emptying and switching valve 2 in the normal position of the pump 11 coming with the solar panel 1 connected is.

Now the functions of the station 8th described in normal heat transfer operation and then becomes an important additional function of the station 8th after a switchover of the emptying and switching valves 2 and 2a described. In normal operation in which the collector circuit of the heat transfer fluid through the elements 1 . 2a . 5 . 18 . 11 and 2 is done, is the station 8th (via the aforementioned integration module 18 ) for the purpose of pressure maintenance, expansion, degassing / deaeration and make-up in the solar circuit integrated. In addition, the pressure vessel in the station 8th calm and clean the liquid heat transfer medium.

The pressure is maintained by means of a spring-loaded pressure relief valve 3 , a pressure maintenance pump 10 and a pressure switch 16 which also indicates the operating pressure. The pressure holding valve 3 opens when a certain limit operating pressure is exceeded and relaxes the heat transfer fluid into a supply fluid F at the bottom of the container 8th into it. Conversely, the pressure holding pump 10 then turned on by an electronic control as soon as passing through the pressure switch 16 measured operating pressure should have become too low. In this way, within certain limits, a defined operating pressure in the solar system is maintained. The setting of the pressure limits is such that, after deducting the hydrostatic pressure of the water columns at the top of the solar panel 1 there is still an overpressure of, for example, 0.5 bar. The static height of the system is thus in the setting of the limit values for the elements 3 and 10 / 16 one.

This pressure-holding function just described is also used for degassing. For this purpose, the pressure holding pump 10 regardless of the pressure switch 16 monitored pressure periodically switched on. As a result, a certain overpressure periodically builds up on the spring-loaded pressure maintenance valve 3 which opens accordingly. The heat transfer fluid is accordingly subject to a pressure drop compared to the operating pressure of the solar system, which adjusts an adiabatic degassing of dissolved gas or dissolved air. The bubbling gases are supplied to the air cushion over the water supply F.

The station 8th also knows a mode quick exhaust, in which the pressure holding pump 10 over a longer period (several minutes or hours) runs to remove coarse air or gas bubbles from the heat transfer fluid. This quick degassing or quick deaerating can in principle be adjusted by hand; However, an electronic activation is preferred after certain operating conditions in the solar system A, for example. An emptying and refilling, are completed. The described degassing function improves the heat conduction properties of the heat transfer fluid and the pressure maintenance of the heat transfer fluid.

A third important function of the station 8th concerns the expansion or thermal expansion. In this case, the heat transfer fluid (initially intended in the solar area A) to be exposed to different temperatures and therefore also assume a different, each incompressible volume. For a temperature-related large volume is an expansion volume C in the station 8th intended. After in the area of the hydraulic switch 5 If a second volume flow coming from the heating area B can mix with the volume flow of the solar installation A, the expansion volume C also contains this expansion volume coming from the area of the heating installation B.

Conversely, if the volume of the heat transfer fluid as a whole by various effects (leaks, evaporation) should have become too low, if it is in the heat carrier about water, through a fresh water feed 9 the missing volume will be supplemented. The fresh water feed 9 contains a system separation, which prevents the heat carrier fluid or water from the area of the solar system A can get into the fresh water connection.

Now a new function of the station 8th described specifically for connection to the solar system A is useful. For this purpose, the solar cycle just described 1 . 2a . 5 . 18 . 11 . 2 by means of the emptying and switching valves 2 . 2a Switched so that the hydraulic switch 5 , the integration module 18 and the solar circulation pump 11 no longer at the solar panel 1 lie. This previous cycle can now take place via the solar collector 1 via a throttle valve 17 close with short-circuit line to maintain a small volume flow. The solar collector is now through the valves 2 and 2a via a ventilation pipe 7 and an emptying tube 7a with an air cushion D of the station 8th connected. This allows the solar collector 1 be relieved to a predetermined, not burdened by severe temperature changes altitude level. The ventilation, which replaces the lowered volume of media D, passes through the ventilation tube 7 from the station 8th taken. The emptying can be set in motion in different ways, for example. By the hanging water column in the emptying tube 7a heavier than the hanging water column in the ventilation pipe 7 , In any case, located at the bottom of the drain pipe 7a a non-return valve 4 , which ensures that the heat transfer fluid can escape downwards, but no air or gas in the drain pipe 7a can be pulled upwards. Accordingly, the ventilation, which finds the heat transfer fluid in the solar collector 1 replaced, through the ventilation pipe 7 on the other side.

The two valves 2 and 2a be used for this additional function of the station 8th controlled by an electronic control temperature dependent. For this purpose, the temperature in the solar panel 1 through a temperature sensor 13 measured. This temperature sensor 13 may be a separate sensor, but it may also be the difference in temperature for the purpose of connecting the solar system A to the heating system B as a differential temperature sensor 13 / 13a already installed temperature sensors 13 be shared.

By means of this electronic control, two temperature limits (provided for safety reasons) can now be specified. The solar collector 1 is emptied as described to the solar panel 1 If the temperature is too low, protect against freezing and freezing. This measure replaces the previously customary mixing of an antifreeze to the heat transfer fluid. On the other hand, even at too high a temperature in the solar collector 1 , which can not be absorbed by the pressure maintenance of the operating pressure in the solar system A, the solar system to be emptied. In this operating condition, a heat request from the heating system B is unlikely anyway. In both cases, the solar panel 1 then again above the level of emptying filled up, as soon as the temperature sensor 13 measured temperature returns to a normal usable temperature range.

The avoidance of the anti-freeze agent (in addition to the non-resinification) also has the advantage that the expansion coefficient of the heat transfer fluid is usually lower, so that the expansion volume C can be kept relatively small. Because the antifreeze has about twice as large expansion coefficient compared to water. The efficiency of the solar system according to the invention does not decrease (as, for example, in the prior art to 50% of the power), but remains evenly high by the pressure maintenance and degassing. The circulation pump 11 Also, it does not suck in any air bubbles, as is often the case with solar systems without pressure maintenance and without degassing.

A

Area solar system

B

Area Heating side or heating system

C

Expansion volume "heating and solar" in the station 8th

D

Reduction volume "Solar" and air return volume "Solar" in the station 8th

e

standing water column in the drain pipe 7a to the level of emptying the solar system A

F

Supply of heat transfer medium or water supply in the station 8th

1

solar panel

1a

Warmth- or cold storage

2 / 2a

emptying and changeover valves

3

spring-loaded Pressure holding valve

4

Check valve at the bottom of the drain pipe 7a

5

hydraulic Soft or mixing container

6

heat exchangers for domestic hot water heating

7

Ventilation tube for solar collector 1

7a

Drain pipe for solar collector 1

8th

station for pressure maintenance, expansion, degassing / venting, Make-up, calming of the heat transfer medium, Cleaning agent intake, recording of the reduction volume D and Air storage D for ventilation of the solar system A

9

Fresh Water Supply with system separation

10

Jockey pump Heating and solar

11

circulating pump Solar

11a

circulating pump heater

12

mixing valve heater

13/13

Temperature sensor, in particular for temperature difference 13 / 13a and for ( 13 ) Filling / emptying the solar system A

14/14

Bypass lines on the heat storage 1a

15

Water gauge with level switch

16

Pressure switch / pressure gauge

17

throttle valve in short circuit

18

Pitot tube as integration module for solar system A

19

Short circuit cable for Pitot tube 18

20

heating circuit or cooling circuit

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 8228065 U1 [0004, 0008, 0013]
• - DE 3237023 A1 [0004]
• - DE 3716396 A1 [0004]
• DE 19705741 C1 [0004]
• - EP 108266 A2 [0004]
• - EP 187683 B1 [0004]

Claims (27)

Solar system (A) with a solar collector ( 1 ) and with a heat transfer fluid, in particular for solar heating support for a heating system (B), characterized in that the circulation of the heat transfer fluid through the solar collector ( 1 ) through two valves ( 2 . 2a ) is switchable - between a so-called hydraulic switch ( 5 ; 1a ), ie a mixing chamber with at least two inlets and two outlets, - and, via emptying and ventilation pipes ( 7 . 7a ), a station ( 8th ) for pressure maintenance, expansion (C), degassing / venting of the heat transfer fluid, for receiving a lowering volume (B) and for an air reservoir (D) for venting the solar collector ( 1 ), and possibly for additional functions. Solar system (A) according to claim 1, characterized in that the station ( 8th ) additionally via an integration module (pitot tube 18 , Short circuit cable 19 ), which a partial flow from the solar circuit ( 1 . 2a . 5 respectively. 1a . 18 . 11 . 2 ) branches off to the solar circuit ( 1 etc.) is connected so that the substream is the station ( 8th ) flows through. Solar plant (A) according to claim 2, characterized by a pressure holding pump ( 10 ) between the station ( 8th ) and the integration module ( 18 ). Solar system (A) according to claim 2 or 3, characterized by a spring-loaded pressure retaining valve ( 3 ) between the station ( 8th ) and the integration module ( 18 ). Solar system (A) according to claim 4, characterized by a pressure monitor ( 16 ) in series with the pressure holding valve ( 3 ). Solar system (A) according to one of claims 2 to 5, characterized by a check valve ( 4 ) at the lower end of the emptying tube ( 7a ). Solar system (A) according to one of claims 1 to 6, characterized by a fresh water feed with system separation ( 9 ) at the station ( 8th ). Solar system (A) according to one of the preceding claims 1 to 7, characterized in that the station ( 8th ) comprises a substantially airtight pressure vessel whose pressure level below one of pressure retaining means (pressure retaining valve 3 , Pressure maintenance pump 10 ) in the heating circuit (B) maintained approximately at atmospheric pressure, ie that the pressure vessel of the station ( 8th ) is essentially "depressurized". Solar system (A) according to one of the claims 1 to 8, characterized in that the heat transfer fluid consists essentially of water that contains no antifreeze. Solar system (A) according to one of the claims 1 to 8, characterized in that the heat transfer fluid is essentially water vapor and contains no antifreeze. Solar system (A) according to one of the claims 1 to 9, characterized in that the heat carrier fluid is a fluid other than water or water vapor and that there is no Contains antifreeze. Solar plant (A) according to one of claims 8 to 11, characterized in that the pressure vessel of the station ( 8th ) contains a storage volume (F) of the heat transfer fluid. Solar plant (A) according to one of claims 8 to 12, characterized in that the pressure vessel of the station ( 8th ) has a volume (C) which determines the thermal expansion volume of the heat transfer medium in the solar circuit ( 1 etc.) and in the heating circuit (B) can accommodate. Solar plant (A) according to one of claims 8 to 13, characterized in that the pressure vessel of the station ( 8th ) has a volume (D), which can accommodate a reduction volume of the solar system (A) up to a discharge level of the solar system (A). Solar plant (A) according to one of claims 1 to 14, characterized in that a solar circulating pump ( 11 ) the heat transfer fluid in the solar circuit ( 1 . 2a . 5 respectively. 1a . 18 respectively. 19 respectively. 8th . 11 . 2 ) is circulated. Solar system (A) according to claim 15, characterized by a throttle valve ( 17 ) in a short-circuit line, which with a partial current the solar collector ( 1 ) and the emptying and switching valves ( 2 . 2a ) bypasses and the partial flow with the circulation pump ( 11 ) is maintained even when the emptying and switching valves ( 2 . 2a ) the solar collector ( 1 ) of the solar circuit ( 2a . 5 . 18 . 11 . 2 ) split off. Solar plant (A) according to one of claims 1 to 16, characterized in that a heat storage ( 1a ), which does not have a heat exchanger between the solar circuit ( 1 etc.) and the heating circuit (B), the hydraulic switch ( 5 ) added or replaced as a mixing chamber. Solar plant (A) according to claim 17, characterized in that the heat storage ( 1a ) in its function as a hydraulic switch ( 1a ) one Inlet and a drain for the solar circuit (A) and an inlet and a drain for the heating circuit (B) has. Solar system (A) according to claim 17 or 18, characterized by a temperature sensor ( 13a ) for determining the heat storage in the heat storage ( 1a ). Solar system (A) according to one of claims 17 to 19, characterized by bypass lines ( 14 and 14a ) for the heat storage ( 1a ), so that the hydraulic switch ( 5 ) acts as the sole mixing chamber for the solar circuit (A) and the heating circuit (B). Solar plant (A) according to one of claims 17 to 20, characterized in that a heating or cooling circuit ( 20 ) via a heating circulation pump ( 11a ) to the heat storage ( 1a ) or to the bypass lines ( 14 . 14a ) connected. Solar plant (A) according to one of claims 17 to 21, characterized in that in the region of the heating side (B) of the heating circuit ( 20 ) via a mixing valve ( 12 ) only partial flows from the area of the solar system (A) or from the heat storage ( 1a ) receives. Solar plant (A) according to one of claims 17 to 22, characterized in that a heat exchanger ( 6 ) for the heating of domestic hot water (BWW) either in the heat storage ( 1a ) or via an inlet and a drain line of the heat exchanger with the heat transfer fluid in the heat storage ( 1a ) connected is. Solar system (A) according to one of claims 1 to 23, characterized by an electronic control which controls the emptying and switching valves ( 2 . 2a ) switches depending on the temperature. Solar plant (A) according to claim 24, characterized in that the emptying and switching valves ( 2 . 2a ) then on the emptying and ventilation of the solar collector ( 1 ), if a temperature sensor ( 13 ) at the solar collector ( 1 ) measures too high or too low a temperature compared to predetermined lower and upper temperature limits. Solar system (A) according to claim 25, characterized in that as a temperature sensor ( 13 ) the signal of the temperature sensor ( 13 ) is shared, which co-determines the differential temperature between the temperature in the heat storage in a conventional manner ( 1a ) and the temperature in the solar collector ( 1 ) to connect the solar system (A). Solar plant (A) according to one of claims 15 to 26, characterized in that the solar circulating pump ( 11 ) is controlled by the usually provided for solar systems control or receives its signal through the additional control according to claim 24 to 26.