EP1730459A1

EP1730459A1 - Coolant circulation device

Info

Publication number: EP1730459A1
Application number: EP04718903A
Authority: EP
Inventors: Achim Mathar
Original assignee: Otto Junker GmbH
Current assignee: Otto Junker GmbH
Priority date: 2004-03-10
Filing date: 2004-03-10
Publication date: 2006-12-13
Anticipated expiration: 2024-03-10
Also published as: WO2005088217A1; EP1730459B1

Abstract

The inventive coolant circulation device comprises an emptiable heat exchanger (101), a coolant medium reservoir (102), a feed line (104) from the coolant medium reservoir (102) to the heat exchanger (101), a discharge line (103) from the heat exchanger (101) to the coolant medium reservoir (102) and a pump (110) which is inserted into the feed line (104) and used to pump the coolant medium in the direction of the heat exchanger (101). The inventive device also comprises a consumer (111), a short line (117) whose lower end leads into the coolant medium reservoir (102) and whose upper end is connected to the feed line (104) between the consumer (111) and heat exchanger (101) by means of a three-way valve (116) or two two-way valves and an intermediate line (114) with a locking valve (115) whose lower end leads into the coolant medium reservoir (102) and whose upper end is connected to the feed line (102) between the three-way valve (116) and heat exchanger (101) or between the two two-way valves and heat exchanger (101).

Description

The refrigeration cycle device

description

The invention relates to a cooling circuit device comprising a) a drainable heat exchanger, b) a cooling medium basin, c) an inflow line from the cooling medium basin to the heat exchanger, d) an outflow line from the heat exchanger to the cooling medium basin, e) a pump interposed in the inflow line, for pumping the cooling medium into Towards the heat exchanger.

The invention also relates to a cooling method with the cooling circuit device according to the invention, wherein a) in normal operation, the cooling medium coming from the consumer / consumers flows in a main circuit through the heat exchanger, is cooled by it and is fed back to the consumer or the consumers via the cooling medium basin and b) in special operation, the cooling medium contained in the heat exchanger flows out.

A cooling circuit device with cross-flow heat exchanger is already known from DE 196 13 910 A1. With the cross-flow heat exchanger presented there, the heat exchanger tubes can be quickly emptied during downtimes and the freezing of the heat exchange liquid prevented and in this way the heat exchanger being prevented from being destroyed. A disadvantage of the known device is that after switching off the cross-flow heat exchanger, there is no further supply of a consumer with cooling water. This is also not necessary with the disclosed cooling circuit device, as long as it is used in areas in which post-cooling can be dispensed with. This is e.g. B. in the plastics industry with cooled injection molding machines.

It is therefore the object of the present invention to provide a cooling circuit device and a cooling method of the type mentioned at the outset, with which also after switching off the heat exchanger, the consumer can still be cooled with water.

This object is achieved in a device of the type mentioned at the beginning by f) a consumer connected in the inflow line, which is arranged after the pump, g) a short line which opens into the cooling medium basin at its lower end and via a three-way valve at its upper end or two two-way valves is connected to the inflow line between the consumer and the heat exchanger and h) an intermediate line with a shut-off valve which opens into the cooling medium basin with its lower end and with the upper end to the inflow line between the three-way valve and the heat exchanger or between the two two-way valves and the Heat exchanger is connected.

The cooling circuit device according to the invention impresses with its simple construction with only one pump. After switching off the heat exchanger, the consumer can still be cooled with water without the aid of a second pump circuit. Water consumption can be minimized and the use of glycol can be completely dispensed with. Usually, about 35% glycol must be added as an anti-freeze so that anti-freeze can be guaranteed down to minus 20 ° C. A circuit requires approx. 2000 liters of water mixed with glycol. Glycol is too expensive, adversely increases the conductivity of water by around 35 microsiemens and also has to be disposed of in an environmentally friendly manner. Since the heat capacity of glycol-water mixtures is poorer than that of water, a system that works with glycol-water mixture must be designed larger than a system that works solely with tap water. External heating can be dispensed with in the device according to the invention. These external heaters, which are intended to prevent the heat exchanger from freezing at low temperatures, work with electricity. There must be no power failure in these systems, otherwise the very expensive heat exchangers would be destroyed. After-cooling of the consumers is guaranteed by the short-circuited makeshift circuit. Such a cooling circuit device can be used in particular in the metal sector with furnaces as consumers.

Advantageous embodiments of the cooling circuit device according to the invention are specified in the subclaims.

The object is achieved in a cooling process of the type mentioned at the outset in that the heat exchanger is removed from the cooling circuit in special operation and the cooling medium only circulates in a makeshift circuit between the cooling medium basin and consumers.

Advantageous embodiments of this cooling method according to the invention are specified in the subclaims.

The first two figures have been included in order to explain and differentiate them from the prior art.

Two forms of embodiment of the device according to the invention are explained below with reference to the 3rd and 4th figures. Show it:

1: a cooling circuit device with cross-flow heat exchanger according to DE 196 13 910 A1,

2: a cross-flow heat exchanger according to DE 196 13 910 A1,

3: an embodiment of a cooling circuit device according to the invention and

4: Another embodiment of a cooling circuit device according to the invention.

In Fig. 1, a cooling circuit device according to the prior art DE 196 13 910 A1 (there Fig. 2) is presented. The cross-flow heat exchanger 1 is connected to a cold container 3 via a drain line 2. From there, the chilled water flows into one Warm container 4. The heated water is then pumped again via an inflow line 5 to the crossflow heat exchanger 1 with the pump 6. The consumer itself is not shown in the cooling circuit device. The cross-flow heat exchanger 1 is provided with a ventilation device 7. During operation, a small amount of heat exchange fluid constantly emerges from the ventilation nozzle 8. This is collected by the funnel 9 and returned to the cold container 3 via the overflow line 10.

2 shows the cross-flow heat exchanger from the prior art DE 196 13 910 A1 (there FIG. 1). This cross-flow heat exchanger 1, which can also be used in the present invention, comprises a frame 12 which is supported on six legs 11 and which carries a housing 13. Fans 14, which are driven by an electric motor, are provided on the upper side of the housing. These ensure that air flows through the cross-flow heat exchanger 1 from bottom to top. The air flowing through is indicated by arrows.

The heat exchange liquid (e.g. water) is supplied to the cross-flow heat exchanger 1 via an inflow element 15. This leaves the cross-flow heat exchanger 1 via a drain element 16. In a known manner, the inflow element 15 and drain element 16 each have a collector 17 or 18, in each of which a connection piece 19 or 20 having a connecting flange opens.

A heat exchange element 21 is arranged within the housing 13 of the crossflow heat exchanger 1. This comprises a plurality of tubes 22 running parallel to one another and heat exchange fins 23 extending at right angles to them. Half of the tubes 22 are connected to the collector 17 of the inflow element 15, the other half to the collector 18 of the outflow element 16. The heat exchange element 21 is shown in FIG the housing 13 is arranged inclined with respect to the horizontal; thus the tubes 22 also have an identical inclination with respect to the horizontal.

A collector 24 is arranged on the side of the cross-flow heat exchanger 1 opposite the inflow element 15 and the outflow element 16. These are velvet tubes 22 connected. In addition, a ventilation nozzle 8 is connected to the collector 24.

During the operation of the cross-flow heat exchanger 1, the heat exchange medium flows via the inflow element 15 into the pipes 22 connected to its collector 17 and exits from the latter at the mouth thereof into the collector 24. From there it enters those tubes 22 which are connected to the collector 18 of the drain element 16.

To drain the cross-flow heat exchanger 1, for example for downtimes, drains 25 arranged on the collectors 17 and 18 of the inflow or outflow element 15, 16 are opened after the circulating pump of the heating or cooling circuit has been put out of operation beforehand. Air flows into the collector 24 through the ventilation connection 8, and the heat exchange liquid flows due to the inclination of all the pipes 12 to both the inflow element 15 and the outflow element 16 and leaves the heat exchange element 21 through the outlets 25.

The flow monitor 26 shown in FIG. 1 and the frost protection thermostat 27 can be used to initiate an automatic emptying.

3 shows a cooling circuit device according to the invention with a main and auxiliary circuit.

The main circuit comprises a cross-flow heat exchanger 101 arranged at the highest point, similar to that which was explained in FIG. 2. The air flowing through the cross-flow heat exchanger 101 is indicated by arrows. The direction of circulation of the water in the main circuit and in the auxiliary circuit is also indicated by arrows.

A cooling medium basin 102, which is filled with water and is connected to the cross-flow heat exchanger 101 via a drain line 103, is arranged lower. This drain line 103 ends below the water level in the cooling medium pool 102. It should end below the water level in order to absorb the oxygen Reduce cooling water to a minimum. A collector 105 is provided on the side of the heat exchanger 101 opposite the inflow line 104 and outflow line 103, to which the heat exchanger tubes 106 and on the other hand a ventilation device 107 are connected. The ventilation device 107 has a ventilation water line 109. The aeration water line 109 connects the aeration device 107 to the cooling medium basin 102. The aeration water line 109 ends above the water level, so that air and no water enter the crossflow heat exchanger 101. Instead of the ventilation water line 109, a ventilation valve can also be provided. The inflow line 104 has a slight upward or downward slope of at least 2% in the area just before and the outflow line 103 in the area shortly after the heat exchanger 101.

The cooling medium basin 102 is connected again to the cross-flow heat exchanger 101 by means of the inflow line 104 and via an intermediate pump 110 and an intermediate consumer 111. The cooling medium basin 102 is preferably made of plastic. The cooling medium basin 102 is provided with a vent fitting 112 with a safety pressure valve and with an overflow 113, which opens briefly when the pressure rises ≥ 0.1 bar. Water is used as the cooling medium.

A furnace system is particularly suitable as a consumer 111. The water heats up at the consumer 111 and is fed through the inflow line 104 to the higher-level crossflow heat exchanger 101 and cools there. The cooled water flows via the drain line 103 to the cooling medium basin 102 and is brought from there back to the consumer 111 by means of the downstream pump 110.

In the event that the cross-flow heat exchanger 101 must be switched off, for. B. during maintenance work or risk of frost, the cross-flow heat exchanger 101 is ventilated. A portion of the water in the cross-flow heat exchanger 101 then flows due to gravity through the drain line 103 to the cooling medium basin 102. This also means that part of the water that is in the warehouses connected to the inflow line 104 Metal pipes 106 is located, can flow, an intermediate line 114 is provided with shut-off valve 115, which ends with its lower end in the cooling medium basin 102 below the water level and is connected with the upper end to the inflow line 104 in front of the cross-flow heat exchanger 101. The intermediate line 114 is intended to end with its lower end in the cooling medium basin 102 below the water level in order to minimize the oxygen absorption of the cooling water.

In the normal case, when the water is to reach the cross-flow heat exchanger 101 through the inflow line 104, the shut-off valve 115 of the intermediate line 114 is closed. The water drainage through the intermediate line 114 to the cooling medium basin 102 is then not possible. Only when the cross-flow heat exchanger 101 is switched off is the shut-off valve 115 opened and the cooled water can flow due to gravity from the section of the inflow line 104 shortly before the cross-flow heat exchanger 101 via the intermediate line 114 into the cooling medium basin 102.

If the water is to continue to circulate without the cross-flow heat exchanger 101, it is switched via a three-way valve 116, which is arranged in the inflow line 104 behind the consumer 111 and in front of the intermediate line 112, in such a way that the water is led directly into the cooling medium basin 102 via a short line 117 flows. Instead of the three-way valve 116, two two-way valves can also be used. The short line 117 ends below the water level in the cooling medium basin 102. The short line 117 should end below the water level in order to reduce the oxygen absorption of the cooling water to a minimum. In this makeshift circuit, the water circulates between the consumer 111 and the cooling medium basin 102 based on the pump output. The water level in the cooling medium basin 102 is controlled by a level monitor 125.

One advantage of the cooling circuit device presented is its damped temperature rise and cooling behavior due to the intermediate cooling medium basin 102. This cooling medium basin 102 absorbs the sudden changes in temperature that occur in consumers, in particular ovens. This considerably simplifies the control settings and the switching cycles of the Fans (14) minimized. In known closed cooling circuits with air coolers, in particular cross-flow heat exchangers, great efforts must otherwise be made in terms of control technology in order to get this problem under control.

FIG. 4 shows a cross-flow heat exchanger 101 and a cooling circuit arrangement according to FIG. 3. However, instead of a consumer 111, two consumers 111 'and 111 "connected in parallel are shown in the form of two ovens. The coils of the ovens give off heat in the process.

A non-return flap 118 and an emergency water valve 119 are arranged in the respective supply section of the inflow line 104 in front of the respective consumer 111 ', 111 ". Should the temperature of the water at one or both consumers 111' and 111" rise too high, the pump fail or in the event of a power failure, cool water - usually normal water from the municipal utility company - can be supplied via the emergency water valve 119 in front of the consumers 11 T and 111 "and after cooling the consumers 111 ^" and 111 "can flow into an outflow channel 108 via the overflow 113 Check valve 118 is to bring the emergency water to the consumers in emergency water operation for cooling, ie to prevent direct drainage of the emergency water to the cooling medium basin 102 and via the overflow 113 into the outflow channel 108. The emergency water can also be used to raise the water level the respective oven coil at a certain level If the water level drops unexpectedly, the oven coil to be cooled would otherwise be destroyed from top to bottom.

In each case a temperature control valve 120 is arranged in the respective supply section of the inflow line 104 after the respective consumer 111 ', 111 ". The temperature of the heated water is determined on this temperature control valve 120. This should be> 70 ° C can be regulated by means of control valves (not shown) by throttling or expanding the water inflows at the respective consumer 111 ', 111 ". Such a temperature control can also be used with a single consumer become. The temperature of the water in the respective sections of the feed lines 104 immediately behind the ovens should be as high as possible. After cooling in the heat exchanger 101, the temperature of the water should still be at least 20 ° C. The temperature of the cooled water is recorded with a means for temperature detection 124, in particular with a PT100.

In Fig. 4, the switchgear 121 is connected in series with the cooling circuit. The switchgear assembly 121 is arranged via its own heat exchanger 122 with the inflow line 104 between the pump 110 and the furnaces 111 ', 111 ". The switchgear assembly 121 heats the water assigned to it. This water can be mixed with 0.3% corrosion agent (inhibitor). It is also possible to work with demineralized water, which flows to the heat exchanger 122 of the switchgear and is cooled there by the cool water of the inflow line 104.

Such a series connection of the heat exchanger 122 is recommended for switchgear 121 with a lower output. The advantage of switching in series is that the circulating quantities of water and thus the pump output can be kept low. In theory, it is also possible to connect the heat exchanger 122 of the switchgear 121 in parallel with the consumers; however, that is expensive. It must also be ensured that a constant cooling capacity is achieved on the expensive switchgear. A switchgear of very high power should be separately via an independent, i.e. H. circuit independent of the furnace circuit.

4 also shows a heat recovery device 123 in the form of a heat exchanger connected in series behind the furnaces. This heat recovery device 123 is optional, i. H. can be switched on if required. Heat recovered via the heat exchanger can e.g. B. be used for heating circuits or hot water circuits.

The cooling circuit presented in Fig. 4 is, for. B. used in furnaces in which 3000 KW heat loss must be carried away during operation. At the weekend, when the stove cannot be used, heat losses must continue to be be performed, which decrease continuously on z. B. up to 190 KW. The cooling circuit must also be switched down accordingly. It may take 12 hours for a brick lining to cool down.

LIST OF REFERENCE NUMBERS

1. Cross-flow heat exchanger 101. Cross-flow heat exchanger

2. Drain line 102. Cooling medium basin

3. Cold container 103. Drain line

4. Warm container 104. Inflow line

5. Inflow line 105. Collector

6. Pump 106. Heat exchanger tube

7. Aeration device 107. Aeration device

8.Ventilation port 108. Outflow channel

9. Funnel 109. Ventilation water pipe

10. Overflow line 110. Pump

11. Leg 111. Consumer

12. Frame 111 \ first consumer

13. Housing 111 ". Second consumer

14. Fan 112. Vent valve

15. Inflow element 113. Overflow

16. Drain element 114. Intermediate line

17. Inflow element collector 15 115. Check valve

18. Collector of the drain element 16 116. Three-way valve

19. Connection piece of the inflow element 15 117. Short line

20. Connection piece of the drain element 16 118. Non-return valve

21. Heat exchange element 119. Emergency water valve

22. Pipes 120. Temperature control valve

23. Heat exchange fins 121. Switchgear

24. Collector 122. Heat exchanger

25. Drains 123. Heat recovery devices

26. Flow switch direction

27. Frost protection thermostat 124. Means for temperature detection 125. Level guard

Claims

claims

1. A cooling circuit device comprising a) an emptied heat exchanger (101), b) a cooling medium basin (102), c) an inflow line (104) from the cooling medium basin (102) to the heat exchanger (101), d) an outflow line (103) from the heat exchanger ( 101) to the cooling medium basin (102), e) a pump (110) interposed in the inflow line (104) for pumping the cooling medium in the direction of the heat exchanger (101),

marked by

f) a consumer (111) interposed in the inflow line (104), which is arranged after the pump (110), g) a short line (117) which opens into the cooling medium basin (102) with its lower end and with its upper end is connected to the inflow line (104) between the consumer (111) and the heat exchanger (101) via a three-way valve (116) or two two-way valves and h) an intermediate line (114) with a shut-off valve (115), which has its lower end in the cooling medium basin ( 102) opens and is connected at its upper end to the inflow line (104) between the three-way valve (116) and the heat exchanger (101) or between the two two-way valves and the heat exchanger (101).

2. Cooling circuit device (101) according to claim 1, characterized in that a) that a cross-flow heat exchanger (101) arranged at the highest point is provided as the heat exchanger, a1) with a plurality of inclined flow-through heat exchanger tubes (106) which are arranged transversely Cooling or heating flow directed towards them can be flowed around and one of which is connected to the inflow line (104) and the remaining ones to an outflow line (103) arranged on the same side of the cross-flow heat exchanger (101), a2) wherein the heat exchanger tubes (106) connected to the inflow line (104) and the heat exchanger tubes (106) connected to the outflow line (103) run essentially parallel to one another in such a way that the heat exchanger tubes (106) connected to the inflow line (104) have an incline in the circuit flow direction and the heat exchanger tubes (106) connected to the outflow line (103) have a slope and a3) wherein a collector (105) is provided on the side of the crossflow heat exchanger (101) opposite the inflow and outflow line (103) on the one hand the heat exchanger tubes (106) and on the other hand a ventilation device (107) are connected.

3. Cooling circuit device according to claim 2, characterized in that the ventilation device (107) via a ventilation water line (109) is connected to the cooling medium basin (102).

4. Cooling circuit device according to one of the preceding claims, characterized in that two or more consumers (111 ', 111 ") connected in parallel are provided as consumers (111).

5. Cooling circuit device according to one of the preceding claims, characterized in that the cooling medium supply to the consumer (111) / the consumers (111 ', 111 ") is individually controllable via control valves.

6. Cooling circuit device according to one of the preceding claims, characterized in that on the inflow line (104) between the consumer (111)

/ the consumers (111 ', 111 ") and the heat exchanger (101) a switchable heat recovery device (123) is arranged.

7. Cooling circuit device according to one of the preceding claims, characterized in that immediately in front of the consumer (111) / the consumers (111 ',

111 ") an emergency water supply line is provided.

8. Cooling circuit device according to one of the preceding claims, characterized in that behind the consumer (1 11) / the consumers (1 1 1 ', 1 11 "), the inflow line (104) is provided with a temperature control valve (120).

9. Cooling circuit device according to one of the preceding claims, characterized in that the inflow line (104) at least in the area in front of the heat exchanger (101) has a slight slope of at least 2% and the outflow line (103) at least in the area after the heat exchanger (101) have a slight gradient of at least 2%.

10. Cooling method with a cooling circuit device according to one of the preceding claims, wherein

a) in normal operation, the cooling medium coming from the consumer (1 1 1) / the consumers (11 1 ', 1 11 ") flows in a main circuit through the heat exchanger (101), is cooled by this and is returned to the cooling medium basin (102) Consumer (11 1) or the consumers (1 1 1 ', 11 1 ") is supplied and

b) in special operation, the cooling medium contained in the heat exchanger (101) flows out,

characterized,

c) that in special operation the heat exchanger (101) is removed from the cooling circuit and the cooling medium only circulates in an auxiliary circuit between the cooling medium basin (102) and consumer (1 11) or consumer (1 1 1 ', 111 ").

11. Cooling method according to claim 10, characterized in that the temperature of the heated cooling medium, seen in the direction of circulation, is detected behind the consumer (111) or the consumers (111 ', 111 ") and increases the flow rate of the medium per unit of time at excessively high temperatures and throttled at too low temperatures.