DE102008040216A1 - cooling system - Google Patents

Abstract

The invention relates to a cooling system for use and removal of excess process and / or engine heat, consisting of a closed primary cooling circuit (3) (primary circuit), which dissipates excess heat, wherein the at least one cooling water reservoir (6) a first region (6a) and a second region (6b) which by means of a separating device (16, 17) are separable from each other.

Description

The The invention relates to a cooling circuit for removing excess Process and / or engine heat such as in one Paper, board or tissue machine.

At the Use of such cooling systems in z. B. a paper machine there is a problem that the coolant, who take over cooling tasks on the machine, mostly oily, oily or other liquids with special properties are such. B. that they have a high Have boiling points and take on simultaneous lubrication tasks or at least to protect against corrosion.

These Coolants are usually harmful to the environment Therefore, they must neither be allowed nor allowed into the environment they about the reuse of a part of the heated Cooling water as process water for z. B. the chemical dilution or get splashed into the papermaking process.

State of the art

A cooling system of this kind is used in the EP1048781B1 described. Here, the contamination of the process water is prevented by a closed primary circuit, a closed secondary circuit and a tertitiärer cooling water line for process water heating are available. A disadvantage of this cooling system is that the waste heat can be transmitted to the tertiary cooling water circuit only to a certain extent by the secondary heat exchanger. Thus, only a part of the potential energy for the heating of the process water is available. Another disadvantage is the increased water consumption due to the higher amount of cooling water that must flow through the heat exchanger and causes more water to evaporate in the cooling tower.

One Another cooling system known to those skilled in the art is to do so has been optimized to be the one transferred to the secondary circuit Waste heat of the primary cooling circuits directly into a cooling water tank initiates and from this cooling water tank then process water for the spray pipes and / or for the dilution of chemicals is removed.

Of the Secondary circuit of this cooling system is so an open system. An oil-water separator in the cooling water tank prevents in case of leakage at the oil coolers no oil gets into the process water.

The Waste heat of the secondary circuit becomes so direct, without the detour over z. B. a heat exchanger, used.

Yet there is a risk of contamination in case of contamination of the process water, so that in case of contamination, the machines must be switched off immediately.

Object of the invention

It is therefore the object of the invention, a cooling circuit to create the benefits of the previous system continues to use and at the same time a contamination of the process water of a paper or Cardboard machine reliably prevented without a case Contamination to cause an interruption of production.

invention description

The Task is done by means of the cooling system with the features of claim 1 or by means of a cooling method with the Characteristics of claim 8 solved.

Further Embodiments of the present invention will become apparent from the Dependent claims.

to Solution to the problem is a cooling system to dissipate excess Process and / or engine heat suggested that off at least one closed primary cooling circuit (primary circuit), which dissipates excess heat, each primary circuit at least one primary fluid / water heat exchanger to transfer the heat to at least one secondary cooling circuit (secondary circuit), each secondary circuit at least one cooling water return tank with a device for separating oil, a sampling point for process water, a cooling water drain, a Cooling device for obtaining flow of cooling water as well as at least one fresh water intake.

Of the at least one cooling water return tank has two areas a first area and a second area which are separable from each other by means of a separating device.

By this design of the cooling system is ensured that even in an accident, z. B. a leakage of a primary heat exchanger the cooling fluid (eg oil) which comes from the primary circuit, can not get into the process water and / or auxiliary water and that the paper machine does not shut down in the event of a fault must become.

One Production loss due to contaminated process water or environmental damage due to polluted wastewater contaminated with chemicals effectively avoided in this way.

The Separator preferably consists of a partition, a Pipe connection between the first area and the second area and a valve, which is closed in case of failure and so reliably prevents cooling water from one area in the other passes.

alternative The separator may also be a slider in the partition.

Of the Secondary cooling water return, coming from the heat exchangers, directs the heated secondary Return cooling water in the first area of the recirculating water tank in front of the oil separator and the cooling water drain and the process water is withdrawn in an area behind the oil separator. Wherein the cooling water drainage takes place in the first area and the process water taken from the second area of the recirculating water tank becomes.

from Coolant drain flows the secondary cooling water to the cooling device, preferably a cooling tower the excess heat to the ambient air emits.

considered the water flow in the secondary circuit is obtained following. The water flow of the cooling water feed / cooling water return is divided in the recirculating water tank in the process water flow and the cooling water flow and in the cooling tower into a cooling water flow and a steam flow. To compensate for the diverted amounts of cooling water must the Cooling system fresh water according to the extracted process water quantity and the evaporation losses in the secondary cooling circuit is supplied.

The Diverting the process water causes the performance of the cooling tower can be designed smaller. For one thing is the to be cooled Less water, on the other hand is an additional Temperature reduction by the fresh water inlet, which removed the Process water quantity compensates.

• – Ableitung überschüssiger Wärme über mindestens einem geschlossenen primären Kühlkreislauf (Primärkreislauf)
• – Übertragung der Wärme auf mindestens einen sekundären Kühlkreislauf (Sekundärkreislauf) mittels eines primären Fluid/Wasser-Wärmetauscher
• – Einleitung des erwärmten sekundären Rücklaufkühlwassers in mindestens einen Kühlrückwasserbehälter mit einer Vorrichtung zum Abscheiden von Öl
• – Entnahme eines Teils des sekundären Rücklaufkühlwassers als Prozesswasser aus dem Kühlrückwasserbehälter
• – Abführen der überflüssigen Wärmeenergie in einer Kühlvorrichtung zur Gewinnung von sekundärem Vorlaufkühlwasser
• – Zuführen von Frischwasser zu Ausgleich der entnommenen Prozesswassermenge und der Verdunstungsverluste im sekundären Kühlkreislauf
• – Unterbrechen der Verwendung des sekundären Rücklaufwassers als Prozesswasser im Falle einer Störung und/oder Verunreinigung des sekundären Rücklaufwassers.

For the cooling process for the use and removal of excess process and / or machine heat, the following process steps result:

• - Dissipation of excess heat via at least one closed primary cooling circuit (primary circuit)
• - Transfer of heat to at least one secondary cooling circuit (secondary circuit) by means of a primary fluid / water heat exchanger
• - Introduction of the heated secondary return cooling water in at least one recirculating water tank with a device for separating oil
• - Removing a portion of the secondary return cooling water as process water from the recirculating water tank
• - Dissipating the excess heat energy in a cooling device for the production of secondary flow cooling water
• - Supply of fresh water to compensate for the amount of process water withdrawn and the evaporation losses in the secondary cooling circuit
• - Stop the use of the secondary return water as process water in case of disturbance and / or contamination of the secondary return water.

By the interruption of the use of the secondary return water as a process water, the machine does not have according to the invention more forcibly shut down because of an interruption the secondary circuit independent of the process water extraction can be regulated. So that the process water continues to have a certain temperature has, gets the needed heat energy from the outside fed. This can be done to some extent the heating of the fresh water during cooling the ancillary units are made.

The excess Process and / or engine heat of the secondary circuit must be 100% discharged through the cooling device during an interruption become.

alternative It is conceivable that in case of an interruption the surplus Process and / or engine heat of the secondary circuit partly via an additional heat exchanger is transferred to the water of the fresh water inlet.

• – Vermeidung der Verschmutzung des Prozesswassers
• – Optimale Energieausnutzung
• – Vermeidung der Aufkonzentration der Wasserinhaltsstoffe durch den
• – ständigen Frischwasserzulauf im Sekundärkreislauf

By solving the object of the invention, the following advantages are achieved:

• - Prevention of contamination of process water
• - Optimum energy utilization
• - Avoiding the concentration of water constituents by the
• - Constant supply of fresh water in the secondary circuit

figure description

Further Features and advantages of the invention will become apparent from the following Description of preferred embodiments with reference on the drawing. Show it:

1 A first embodiment of the cooling device according to the invention

2 a second embodiment of he Cooling device according to the invention with extended functions

The 1 shows a cooling system according to the invention a paper machine with three parallel primary circuits, each with a flow 3.1 - 3.3 and return 3.4 - 3.6 which the devices 3.7 - 3.9 (eg bearings, press rollers, other machine parts, etc.) with the help of a flowing fluid - here oil cooling.

In the primary circuits are located between the heats 3.1 - 3.3 and the returns 3.4 - 3.6 each primary fluid / water heat exchanger 2.1 - 2.3 , with whose help the waste heat to another secondary cooling circuit 2 is transmitted. The primary cooling circuit 3 forms opposite the secondary cooling circuit 2 a closed circuit, only with the heat exchanger there is an indirect point of contact.

In the secondary cooling circuit 2 are the primary heat exchangers 2.1 - 2.3 connected in parallel and above the flow 4 and the return 5 connected with each other.

From the primary heat exchangers 2.1 - 2.3 is the heated cooling water over the return 5 in the upper area of a recirculating water tank 6 initiated. The recirculating water tank 6 is in two parts 6a . 6b divided, with in first area 6a an apparatus for separating oil is integrated.

The two areas 6a . 6b are normally interconnected and can in case of failure, z. B. in contamination of the cooling water with oil, are separated from each other. The separation device can, as shown, from a partition 12 in the recirculating water tank 6 and a pipe connection 16 with a valve 17 consist. Alternatively, a closable opening in the partition wall is conceivable or a pumping device which the cooling water from the first area 6a in the second area 6b inflated.

The process water 10 will be from the second section 6b taken, being on the connection of the areas 6a . 6b warm cooling water flows according to the extracted process water quantity.

The required cooling water for the secondary circuit is that from the first area 6a of the recirculating water tank 6 taken and from there to a cooling device, here a cooling tower 8th with a fan to support the cooling air flow, pumped. From there it passes through the cooling water supply to the heat exchangers 2.1 - 2.3 , Between the cooling tower 8th and the heat exchangers 2.1 - 2.3 is usually still a cooling water circulation tank 19 with fresh water intake 15 , a pump 18 as well as a filter.

The cooling tower releases the excess heat in the form of steam to the environment, the resulting loss of water is via the fresh water inlet 15 balanced.

In addition, about the fresh water intake 15 the extracted process water quantity compensated in normal operation.

Also the cooling water tank 6 is in the second area 6b with a fresh water intake 14 provided with the removal of the process water 10 when the valve is closed 17 compensate. To preheat the fresh water, the waste heat of various aggregates can still be used before running in, for. B. compressors, pumps, etc

Alternatively, once again, the residual heat of the cooling water can be used on the way to the cooling tower. This plays a role especially if the direct use of the return energy from the return 5 can not be used in the event of a fault.

1

cooling system

2

Secondary circuit

2.1-2.3

Fluid / water heat exchanger

3

Primary circuit

3.1-3.3

primary Cooling water supply

3.4-3.6

primary Cooling water return

3.7-3.9

cooler

4

secondary Cooling water supply

5

secondary Cooling water return

6

Rear cooling water tank

6a, 6b

first / second Cooling water area

7

oil separator

8th

cooler

9

Cooling water outlet

10

process water

11

fan

12

partition wall

13

heat exchangers

14 15

fresh water

16

Connecting pipeline

17

Valve

18

pump

19

Cooling water circulation container

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

• - EP 1048781 B1 [0004]

Claims (11)

Cooling system for the use and removal of excess process and / or engine heat comprising: - at least one closed primary cooling circuit ( 3 ) (Primary circuit), which dissipates excess heat, - per primary circuit ( 3 ) at least one primary fluid / water heat exchanger ( 2.1 to 2.3 ) for transferring the heat to at least one secondary cooling circuit ( 2 ) (Secondary circuit) - per secondary circuit ( 2 ) at least one cooling water return tank ( 6 ) with a device ( 7 ) for separating oil, a removal point for process water ( 10 ), a cooling water drain ( 9 ), a cooling device ( 8th ) for obtaining flow of cooling water ( 4 ) as well as at least one fresh water feed ( 14 . 15 ) characterized in that the at least one recirculating water tank ( 6 ) a first area ( 6a ) and a second area ( 6b ) which by means of a separating device ( 16 . 17 ) are separable from each other. Cooling system according to claim 1, characterized in that the separating device consists of a partition wall ( 12 ) a pipe connection ( 16 ) between the first area ( 6a ) and the second area ( 6b ) and a valve ( 17 ) consists. Cooling system according to claim 1, characterized in that the separating device a slide in the partition ( 12 ). Cooling system according to claim 1, characterized in that the secondary cooling water return ( 5 ) of the heat exchangers ( 2.1 to 2.3 ) in the first area ( 6a ) of the recirculating water tank ( 6 ) in front of the oil separator ( 7 ) and the cooling water drain ( 9 ) and the removal of the process water ( 10 ) in an area behind the oil separator in the first area ( 6a ) are arranged. Cooling system according to claim 1, characterized in that the process water ( 10 ) from the second area ( 6b ) of the recirculating water tank ( 6 ) is taken. Cooling system according to claim 1, characterized in that the cooling device ( 8th ) is a cooling tower, which releases the excess heat to the environment. Cooling system according to claim 1, characterized in that the secondary cooling water supply ( 4 ) after the cooling device ( 8th ) Fresh water according to the amount of process water withdrawn ( 10 ) and the evaporation losses in the secondary cooling circuit ( 2 ) is supplied. Cooling method for the use and removal of excess process and / or engine heat with the following method steps: - dissipation of excess heat via at least one closed primary cooling circuit ( 3 ) (Primary circuit) - transfer of heat to at least one secondary cooling circuit ( 2 ) (Secondary circuit) by means of a primary fluid / water heat exchanger ( 2.1 to 2.3 ) - Introduction of the heated secondary return cooling water ( 5 ) in at least one recirculating water tank ( 6 ) with a device ( 7 ) for separating oil - removal of part of the secondary return cooling water ( 5 ) as process water ( 10 ) from the recirculating water tank ( 6 ) - dissipate the excess heat energy in a cooling device ( 8th ) for obtaining secondary flow cooling water ( 4 ) - supply of fresh water ( 14 ; 15 ) to equalize the amount of process water withdrawn ( 10 ) and the evaporation losses in the secondary cooling circuit ( 2 ), characterized in that the use of the secondary return water ( 5 ) as process water ( 10 ) in the event of a disturbance and / or contamination of the secondary return water ( 5 ) is interrupted. Cooling method according to claim 8, characterized in that at the interruption of the use of the secondary return water ( 5 ) as process water ( 10 ) the process water ( 10 ) The required heat energy is supplied from the outside. Cooling method according to claim 8, characterized in that at the interruption of the use of the secondary return water ( 5 ) as process water ( 10 ) the excess process and / or engine heat of the secondary circuit completely via the cooling device ( 8th ) is discharged, Cooling method according to claim 8, characterized in that at the interruption of the use of the secondary return water ( 5 ) as process water ( 10 ) the excess process and / or engine heat of the secondary circuit partially via a heat exchanger ( 13 ) to the water of the fresh water inlet ( 14 ) is transmitted.