DE19963473A1 - Structure for equalizing temperature in liquid cycles contains pumps to circulate coolant and a device for storing up a cooling liquid connected to cooling consumers and a heat exchanger via pipework. - Google Patents

Abstract

A heat exchanger is designed in the form of an earth probe installation (1) with multiple earth probes (2) fitted in parallel circuits and set apart from each other. These probes come into direct contact with the surrounding soil (3) and rock formation (4). The earth probe installation is coupled to a consumer (9) through a cooling liquid store.

Description

The invention relates to an arrangement for tempering Liquid circuits, especially of low temperature Cooling circuits containing a storage device a coolant that is piped to cool with institutions (consumers) on the one hand and with little At least one heat exchanger, on the other hand, a liquid forming a circuit, is connected, and pumps for circulation the coolant.

In industry, a variety of manufacturing and Processing methods used in which a cooling of the Machines themselves or at least the products during manufacture position process is required. As a cooling medium, skin is used fig water or brine or the like. This cooling medium should remove the process heat from the production process and he therefore warms more or less. So it becomes warm gie transferred to the cooling medium, which then with suitable Means must either be released to the environment, or can be converted to useful energy using a heat exchanger.

In the former case there are cooling towers (use of the evaporation cold), free cooler with and without electric fan (convection cooling), or chillers application. In the second case are dependent on the existing temperature differences  zen either simple heat exchangers or heat pumps used. In any case, the cooling device is operated Electrical energy needed to run the pumps, the fans or also the compressors of the cooling machines or heat pumps to operate. Depending on the required cooling capacity, the Electrical energy needs can be very substantial. With high cooling medium temperatures, it is relatively easy to use suitable ones Heat coupling to obtain useful energy. Are the coolants temperatures, however, low, for example below 30 ° C, see above useful energy can only be obtained with the help of heat pumps, which is uneconomical and costly. Heat pumps are known to be relatively unfavorable energetically and require in comparison to the recovered thermal energy high energy input.

The general goal, however, is to significantly reduce energy consumption and thus significantly reduce pollutant emissions, especially CO ₂ emissions and consequently the environmental impact.

For example, in the plastics processing industry most of the electrical energy used is converted into heat changes. The proportion of this heat that is not due to radiation and convection is given to the environment by ge targeted cooling (50% on average). This is necessary because otherwise damage to machines and systems would occur, which would result in their destruction. The would mean that technological processes would not be feasible.

Therefore, to cool the production facilities and the Manufactured products used media that usually be recooled with the help of electrical energy. That means, that energy is expended to energy from manufacturing process to draw. Because the cooling media in the plastic processing industry mostly a temperature ni have a level of <= 30 ° C, this potential is present insufficient due to the low work capacity uses.  

To reduce the amount of energy used for cooling and thus to reduce the environmental impact of CO ₂ , attempts were made to divide the cooling circuits according to cold water temperatures, for example, or to relieve the cooling machines in winter by using free coolers. Attempts have also been made to use the groundwater or bank filtrate for cooling, but this is not available at every location and, on the other hand, requires special safety precautions to prevent contamination of the groundwater, even accidental, with certainty.

The invention is therefore based on the object of an arrangement for tempering liquid circuits, in particular of Low-temperature cooling circuits with a simple structure create that is cost-effective and low-maintenance in the long run can be used and in which the use of energy is considerable is reduced.

The problem underlying the invention is at an arrangement of the type mentioned solved in that the heat exchanger in the form of an earth probe system with a A plurality of spaced apart and parallel or earth probes connected in series, wherein the geothermal probes over thermal bridges directly with the surrounding one Soil or rock are connected and that the Erdson the system via a coolant reservoir with the Ver user is coupled.

The particular advantage of such a solution is besides the one fold structure, the higher availability and the long life Life can be seen especially in the low operating costs. The simple structure also increases the ease of maintenance speed or the maintenance costs can be reduced. From the significantly reduced energy consumption compared to one conventional cooling system, which can be up to approx. 80%, results in a very good environmental compatibility, so that Pri be conserved.  

The geothermal probes are preferably in the shallow range brought and stand with the surrounding soil or rock in direct thermal contact. The one to be implemented in individual cases The depth of the earth probes is determined from the geological conditions conditions and from the required cooling capacity.

In a continuation of the invention, the earth probes are in Boh stanchions arranged, the gap between the outside coat the earth probe and the surrounding rock with a well thermally conductive filling compound is filled. That way a particularly good thermal contact is achieved. The is preferred Thermal conductivity of the filling compound approximately to the thermal conductivity adapted to the surrounding rock, which is best explained by the Use of low-viscosity concrete is achieved, which is the same the borehole stabilized at an early stage.

Plastic geothermal probes are particularly cost-effective tubes are manufactured. Such geothermal probes are extreme durable and have sufficient thermal conductivity. Conventional plastic pipes can, for example, conduct heat ability that largely corresponds to that of granite.

In a further embodiment of the invention, the material al the plastic pipes to increase the thermal conductivity Aggregates included. This can be done in a simple manner achieve adaptation to special geological conditions, which is particularly advantageous if the heat conduction ability of the surrounding soil is particularly good.

To make the installation of the To enable geothermal probes, these consist of a pre-assembled th U-shaped or double U-shaped arrangement, wherein the individual pipes at intervals by spacers are connected.

In one variant, the geothermal probes can also consist of several koa xial nested plastic pipes, where the coolant to be cooled down in the outer ring and in  inner tube is led upwards.

A further continuation of the invention is thereby characterized records that the liquid reservoir from at least one Cold water and at least one hot water tank exists and that the cold water and hot water tanks underground or are arranged above ground.

The tanks are preferably made of PE and are therefore special durable and inexpensive, the cold water and the Hot water tank can be sunk directly into the ground and in be in direct contact with him.

In a special embodiment of the invention, the earth probe system assigned to free cooler, the preferred temperature controlled the geothermal system can be switched on.

Additional cooling with a chiller can also be used lower power are provided with the help of high summer temperatures the cooling capacity of the Erdson system and the free cooler can be added.

A special embodiment of the invention is thereby characterized records that a consumer supplied with hot water Hot water tank is provided with the geothermal system and the parallel-connected free cooler is connected to that of the geothermal system and / or the free cooler generated cold water via cold water pipes to a temporary store is passed through a pipe to the chiller is connected that the chiller with a cold water tank is connected to the Ver user is connected.

The cold water tank is also equipped with a cold water supply, with the help of water losses in the cooling cycle can be balanced.

To ensure that only a minimal electrical  Power is installed are the geothermal probe system, the Frei cooler and the chiller each have a separate coolant assigned to pump. This means that the pumps can be used exactly for each lig required pump output of the respective cooling circuit be interpreted.

There are also several sensors, especially temperature sensors provided, each in the inlet of the hot water tank and the Cold water tanks are arranged with a central Control unit are connected and with which the pumps of the respective cooling circuits can be switched on as required can.

It is advisable to use all pipes as plastic training pipelines, which makes them extremely low-maintenance are. When using metal pipes, all upper earth pipes, especially if this one have a large length, provided with thermal insulation to exclude temperature influences in the environment.

To further reduce energy consumption, the Cooling capacity of the geothermal probe system approx. 80% of the average total cooling power required, the lead temperature between <= 14 ° C and the return temperature <30 ° C especially for processing processes in the plastics industry should be.

With an appropriate control, an optimal adjustment can be made the cold water temperature to the required tech biological conditions are guaranteed.

An inadmissible permanent warming of the soil can be prevented if the geothermal probe system with the Leerlau fenden free cooling system is coupled. The outside temperature drops below the required return temperature of the cooling medium um, the free cooler can automatically at least dissipate heat partially take over. This relieves the burden on the cooling of used soil or rock.  

Using a computer-aided simulation, it was determined that after about 10 years of use, the slow Er heating the environment of the geothermal probe system with appropriate Driving style comes to a standstill.

As a rule, the installed production capacity without 100% of the time, is already combination of the geothermal probe system with a small one Chiller useful to compensate for peak loads. At the same time the expenses for the probe field reduced can be decorated.

In a special embodiment of the invention, the earth probe system via a heat exchanger on the liquid circuit coupled. This offers the particular advantage that in the event of contamination of the liquid circuit, e.g. B. with Oil, no pollutants can get into the ground.

Such a cooling circuit is basically for cooling purposes any production processes in the low temperature range suitable where an energy recovery due to the low Labor is uneconomical. However, there are also completely different applications are conceivable. So z. B. the tempe ration of lanes, such as bridge lanes or deep-freeze gene entries with comparatively little technical effort conceivable.

The invention is intended to be explained in more detail below using exemplary embodiments are explained. Show in the accompanying drawings

Fig. 1 shows an example of a particularly simple variant of a low-temperature cooling circuit according to the invention with a geothermal system, in which the Erdson reach through the soil and through a groundwater-bearing rock layer;

Fig. 2 is a schematic representation of a cooling circuit according to the invention according to Figure 1, which is supplemented with a free cooling system.

Fig. 3 is a schematic representation of a cooling circuit according to the invention according to Fig 2, which is supplemented with a refrigeration machine, which serves the power peak coverage;

Fig. 4 is a schematic representation of a cooling circuit according to the invention corresponding to Figure 3, in which the coupling to the geothermal system takes place via a heat exchanger. and

Fig. 5 is a schematic representation of a cooling circuit according to the invention according to Fig. 2, in which a heat pump is provided for operating a heating system.

From Fig. 1, the schematic structure of an arrangement according to the invention for tempering a low-temperature cooling circuit is evident. The core of the arrangement is an earth probe system 1 , consisting of a plurality of earth probes 2 connected in parallel or in series, which are introduced into the soil 3 or the rock 4 . The depth to which the geothermal probes extend and their number is determined by the cooling capacity to be installed. The geological and hydrogeological conditions must also be taken into account. If the geothermal probes 2 extend through groundwater 5 , for example, significantly more heat can be dissipated in a short time than through dry rock 4 . In any case, the geological and hydrogeological conditions prevailing in the intended area of application must first be explored before the geothermal probe system 1 can be dimensioned.

The geothermal system 1 is also connected via a Kaltwasserlei device 6 to a cold water tank 7 , which in turn is connected to the consumer 9 via a further cold water pipe 8 (lead). Under consumer 9 is to be understood in any manufacturing process, for example, in which the process heat is to be dissipated via a low-temperature cooling circuit.

The water heated by the process heat is then passed through a hot water pipe 10 (return) first into a hot water tank 11 and from there via a further warm water pipe 12 by means of a pump 13 into the geothermal system 1 . The cold water is supplied to the consumer via a pump 13 'connected to the cold water line 8 .

Such a low-temperature cooling circuit can be operated at extremely low cost and requires very little maintenance, for example to check the functionality of the geothermal probe system 1 .

The geothermal probes 2 can be produced inexpensively from plastic pipes, a pre-assembled U-tubular, double-U-tubular or also a coaxial arrangement can be simply inserted into a borehole. In order to produce good thermal contact, in particular with the surrounding rock 3 , the space between the borehole wall and the earth probe 2 is filled with a thin, liquid, concrete-like mass. Technologically, this can be done in such a way that the earth probe 2 is introduced into the borehole in the coaxial arrangement with an additional pipe surrounding it, and the thin concrete is filled in through the additional pipe and at the same time the additional pipe is pulled out of the borehole.

In the case of using the double U-tube arrangement, the four tubes at intervals with spacers / connecting elements ten (not shown) provided, one in the middle Hole provided for receiving a central additional pipe is. This central additional tube is used to feed the thin liquid concrete-like mass and is also during the Backfilling pulled out of the borehole.

Fig. 2 shows an arrangement for tempering a low-temperature cooling circuit, which is supplemented by a free cooler 14 . The free cooler 14 is connected via pipes 15 to the warm water tank 11 , the water to be cooled being pumped by a pump 16 through the free cooler 14 and from this via a pipe 15 'into the cold water tank 7 .

Through the use of this additional free cooler 14 , it is possible to relieve the geothermal probe system 1 from outside temperatures which are below the return temperature, or to switch off the temperature completely from a certain temperature difference to the required cold water.

To compensate for peak loads, a low-power refrigeration machine 17 can be provided in accordance with FIG. 3. The basic structure of the low-temperature cooling circuit corresponds to that of FIG. 2, with an intermediate store 18 being additionally provided here, which is fed via the cold water line 15 'of the free cooler 14 and the cold water line 6 of the geothermal system 1 . On the output side, the intermediate storage 18 is coupled to the refrigerator 17 via a pipeline 19 and a pump 20 . The additionally cooled by the Kältemaschi ne 17 if necessary cooling water is fed via a pipe 21 into the cold water tank 7 and from there to the consumer.

If the additional cooling capacity of the refrigeration machine 17 is not required, the water from the intermediate store 18 can be passed directly into the cold water sertank 7 via the hydraulic compensation line 22 . To compensate for cooling water losses, a water feed 23 is still provided. By using the refrigeration machine 17 , it is possible to design the geothermal probe system 1 for approximately 80% of the average cooling capacity required.

From Fig. 4, a cooling circuit is shown in FIG. 3 shown, wherein the ground probe 1 is coupled via a heat exchanger 25. Since no additional tank for volume compensation is provided here, a special expansion vessel 26 is required. The connection of the heat exchanger 25 to the Erdson denanlage 1 takes place on the primary side by switching on the cold water line 6 and the hot water line 12 and on the secondary side by connection to the intermediate storage 18 and the hot water tank 11 . In addition, a further pump 24 must be provided on the primary side of the heat exchanger 25 who the. By using the heat exchanger 25 , a particularly high level of operational safety and very good environmental protection are achieved. This is particularly important when there is a risk that the cooling circuit z. B. can be contaminated with oil. It goes without saying that the heat exchanger 25 can of course also be arranged elsewhere. So it is also possible, for example, to connect it between the hot water pipe 10 and the cold water pipe 8 .

Fig. 5 shows a supplement to the cooling system, in which the earth probe system 1 is additionally equipped with a heat pump 27 . The heat pump 27 is ruled out by three-way valves 28 , 29 to the cold water line 6 and the hot water line 12 . In order to achieve the required water cycle on the secondary side, a further pump 30 is provided. Furthermore, a pressure compensation vessel 31 is connected to the supply line 32 in order to ensure the necessary operational reliability even in the event of accidental pressure surges. The heat pump 27 can be connected to a heating circuit, so that during the times when the geothermal probe system 1 is not required or is switched off, it can follow a switch to heating. This has the particular advantage that the thermal energy supplied to the rock can be recovered in winter. However, this also means that excessive heating of the rock can be prevented.

The performance of a geothermal probe system according to the invention essentially from the energy transport in the ground or in the rock certainly. This energy transport is influenced by the Groundwater thickness, the groundwater flow rate and especially the thermal conductivity of the surrounding one Rock. The flow rate of groundwater is in  usually between a few meters a year and 0.1 m / sec. Out from this fact it follows that for the geothermal probes position used material with regard to thermal conductivity usually not determining the performance of the geothermal system is.

All tanks 7 , 11 and the intermediate storage 18 can be manufactured from commercially available PE, which can be done particularly inexpensively, for example, by blowing. Of course, the tanks can also be made of other materials, such as. B. PVC by plastic welding or made of stainless steel.

For the safety of the overall system, it is important that when several tanks 7 , 11 , 18 are used, these are connected to one another via hydraulic compensation lines 22 .

It is also possible to use a single tank that is functionally divided instead of several tanks with different functions. Thus, the cold water tank 7 and the hot water tank 11 could be combined to form a single tank by introducing the cold and warm water in layers or in which there is a horizontal division through a bulkhead. In the latter case, the bulkhead in the bottom area of the tank is provided with an opening for the necessary hydraulic compensation.

In addition, there is the possibility of the entire system as build a closed system, d. H. the tanks are full constantly closed, causing accidental contamination of the Water and atmospheric oxygenation can be prevented can.

In any case, it makes sense to use the feed lines Lines with which the respective tank is filled, as long interpret that in any case completely into the water immersed. This will result in an enrichment of the Prevents water with oxygen.  

In order to save energy through a cooling according to the invention To clarify the cycle, a conventional 200 kw Cooling system compared with a cooling system according to the invention. Further boundary conditions are an electricity price of 11 Pf./kwh and a thermal output of the double U-shaped earth probe of 35 W / m.

The result is shown in the following table:

Reference list

1

Geothermal system

2nd

Earth probe

3rd

soil

4th

rock

5

Groundwater

6

Cold water pipe

7

Cold water tank

8th

Cold water pipe

9

consumer

10th

Hot water pipe

11

Hot water tank

12th

Hot water pipe

13

pump

13

'Pump

14

Free cooler

15

Pipeline

16

pump

17th

Chiller

18th

Cache

19th

Pipeline

20th

pump

21

Pipeline

22

hydraulic pressure equalization

23

Water supply

24th

pump

25th

Heat exchanger

26

Expansion tank

27

Heat pump

28

Three-way valve

29

Three-way valve

30th

pump

31

Pressure compensation vessel

32

Supply

Claims (24)

1. Arrangement for the tempering of liquid circuits, in particular of low-temperature cooling circuits, containing a device for storing a cooling liquid, which is connected via pipes to the devices to be cooled (consumer) on the one hand and with at least one heat exchanger on the other, forming a liquid circuit is, and pumps for circulating the cooling liquid, characterized in that the heat exchanger in the form of an earth probe system ( 1 ) is formed with a plurality of spaced mutually spaced and parallel or in series switched ge probe ( 2 ), wherein the geothermal probes ( 2 ) are directly connected to the surrounding earth ( 3 ) or rock ( 4 ) and that the geothermal probe system is coupled to the consumer ( 9 ) via a coolant reservoir. 2. Arrangement according to claim 1, characterized in that the earth probes ( 2 ) extend into the shallow area and are in direct thermal contact with the surrounding soil ( 3 ) or rock ( 4 ). 3. Arrangement according to claim 2, characterized in that the geothermal probes ( 2 ) are arranged in earth bores, the space between the outer jacket of the geothermal probe ( 2 ) and the surrounding rock ( 4 ) is filled with a good heat-conducting filler. 4. Arrangement according to claim 3, characterized in that the thermal conductivity of the filling compound is adapted approximately to the thermal conductivity of the surrounding rock ( 4 ). 5. Arrangement according to claim 4, characterized records that the filling compound be a thin is clay-like material. 6. Arrangement according to one of claims 1 to 5, characterized in that the geothermal probes ( 2 ) consist of plastic pipes. 7. Arrangement according to claim 6, characterized records that the material of the plastic pipes Impact to increase the thermal conductivity ent holds. 8. Arrangement according to claim 6 and 7, characterized in that the geothermal probe system ( 1 ) consists of a pre-assembled u-tubular or a double u-tubular arrangement, the individual tubes being connected at intervals by spacers. 9. Arrangement according to claim 6 and 7, characterized in that the geothermal probes ( 2 ) from several ren coaxially arranged plastic tubes are available, the cooling liquid to be cooled down in the outer ring and out in the inner tube. 10. Arrangement according to one of claims 1 to 9, characterized in that the liquid reservoir consists of at least one cold water and at least one hot water tank ( 7 , 11 ) and that the cold water and hot water tanks ( 7 , 11 ) are arranged underground and above ground . 11. The arrangement according to claim 10, characterized in that the tanks ( 7 ; 11 ) consist of PE. 12. Arrangement according to one of claims 1 to 11, characterized in that the cold water and the hot water tank ( 7 , 11 ) are sunk directly into the ground ( 3 ) and are in direct contact with it. 13. Arrangement according to one of claims 1 to 12, characterized in that the geothermal system free cooler ( 14 ) are assigned. 14. Arrangement according to claim 13, characterized in that the free cooler ( 14 ) temperature control ert the geothermal system ( 1 ) can be switched on. 15. Arrangement according to one of claims 1 to 14, characterized in that for the additional cooling a chiller ( 17 ) of lower power is vorgese hen. 16. Arrangement according to one of claims 1 to 15, characterized in that a hot water tank ( 11 ) supplied by the consumer ( 9 ) with hot water is provided, which is connected to the geothermal system ( 1 ) and the parallel-connected free cooler ( 14 ), that the he generated by the geothermal probe system and / or the free cooler cold water via cold water pipes ( 6 , 15 ') in an intermediate storage ( 18 ) which is connected via a pipe ( 19 ) to the refrigerator ( 17 ) that the refrigerator ( 17 ) is connected to the cold water tank ( 7 ), which is connected to the consumer ( 9 ) via a further pipe ( 8 ). 17. Arrangement according to one of claims 1 to 16, characterized in that the Kaltwas sertank ( 7 ) is provided with a cold water feed ( 23 ). 18. Arrangement according to one of claims 1 to 17, characterized in that the geothermal system ( 1 ), the free cooler ( 14 ) and the refrigerator ( 17 ) each have a coolant pump ( 13 , 16 , 19 ) is assigned. 19. Arrangement according to one of claims 1 to 18, characterized in that a temperature sensor is arranged in the inlet of the hot water tank ( 11 ) and the cold water tank ( 7 ), which is connected to a central control unit. 20. Arrangement according to one of claims 1 to 19, characterized in that the Kühllei stung the geothermal system ( 1 ) is approximately 80% of the total cooling capacity required. 21. Arrangement according to one of claims 1 to 20, there characterized by that the lead temperature (cold water temperature) is between <= 14. 22. Arrangement according to one of claims 1 to 21, there characterized by that the return temperature (hot water temperature) is <30 ° C. 23. Arrangement according to one of claims 1 to 22, characterized in that the geothermal system ( 1 ) via a heat exchanger ( 25 ) is coupled to the liquid speed circuit. 24. Arrangement according to one of claims 1 to 23, characterized in that the Erdson denanlage ( 1 ), which serves primarily for cooling in the summer months, uses geothermal energy for heating purposes during the heating period via a heat pump system ( 27 ).