DE102005043330B4 - Devices for ice storage and direct cooling - Google Patents

Abstract

contraption for ice storage with a container (1) for receiving water (2) and at least one container (1) passing through the tube (4) for guidance a refrigerant, being in the container (1) on a lateral surface (9) of the tube (4) ice (11) is formed when the refrigerant is evaporated in the tube (4), characterized in that the lateral surface (9) of the tube (4) surface elements (10, 13, 14, 15, 16, 17) for has the formation of ice.

Description

The The present invention relates to an ice storage device according to the preamble of patent claim 1 and an apparatus for direct cooling a liquid according to the preamble of claim 2.

Ice storage are latent storage, the cold energy in the form of ice during the phase transition of Save water on ice, the so-called "store". During the subsequent "unloading", this cold energy is released by defrosting Ice back to the cold net issued. Due to the ice storage, fluctuating energy peaks can occur be covered. As a rule, charging at night and unloading during the day carried out, so the daily Cooling load peaks covered by the ice storage system.

devices for direct cooling are used to cool one Liquid, preferably to cool water, which circulates in a separate consumer network.

Either Devices for storing ice as well as devices for direct cooling come predominantly in the air conditioning industry, where they used for the air conditioning of buildings and in process refrigeration plants, which a corresponding cooling capacity for the Food preparation, in particular milk and cheese products, deploy, deployed. Other main areas of application are in the provision of a process refrigeration for the chemical industry, Pharmaceutical industry, breweries etc.

Of the Basic structure of an ice storage device and the basic structure of a Device for direct cooling are basically similar. These usually consist of a container filled with water, in which a tube bundle system is arranged and this container helical, stacked or spiral interspersed. In the tubes of the tube bundle is in circulation in usually a refrigerant, such as ammonia, Frigen, etc. or a refrigerant in the Form of a water-glycol mixture (brine), guided. The tubes of the tube bundle stand with a chiller in conjunction, wherein the ice storage device or the device for direct cooling to the chiller can be arranged either in series or parallel connection. These Devices are usually each between an evaporator the refrigeration system and a consumer or cold water network arranged.

In the evaporator of the refrigeration system becomes the refrigerant or the brine (brine) on for example, cooled to -5 ° C and flows through then the tube bundle inside the container, which also causes the water in the container to be cooled accordingly. Preferably, the tube bundle system arranged such that the refrigerant or the brine the Flows through pipes in a counterflow principle.

at the ice storage device, it is the purpose that through the Freezing of water Ice first forms on the lateral surface of the tubes and attaches itself there. The full storage capacity of the ice storage device is reached when the total amount of water in the container or Tank is frozen or a Eisstärkenmeßanlage the switch-off gives. The removal of the cooling capacity, i.e. Unloading takes place in the opposite sense. This can be for one through the tube bundle Brine (brine) with a cooling one Temperature guided become. As a result, the ice melts on the lateral surface of the tubes and thus cools over them Release of heat of fusion the brine. For systems with refrigerant in the tube bundle can lead to the other the discharge over a warm water return done directly in the pool. The ice storage device is completely unloaded, if there is no more ice in the container is available.

An example of an ice storage device is shown in the European patent application EP 0 927 861 A1 , In this, several heat exchangers are provided to increase the efficiency, wherein a heat exchanger is located in the interior of the ice storage tank and is formed of U-shaped curved and parallel cylindrical tubes through which flows the refrigerant to bind ice on the cylindrical surface of the tubes ,

In addition, it is from the US 5,193,357 known to provide evaporator tubes with flat elements to form ice cubes of defined size, wherein the sheet-like elements are designed such that they allow a simple, automatic release of the ice cubes formed on the evaporator tubes for further use.

For ice storage devices, a distinction is made between full storage and partial storage. In the case of full storage, for example, the refrigeration requirement of a building is covered exclusively by the capacity of the ice storage, without a chiller being used during the cooling phase. The chiller is used exclusively to charge the ice storage, especially during the night, in which the building does not need to be appropriately air-conditioned. In a partial storage, the base load is covered by the chiller, while the ice storage device only to cover a possibly occurring peak load is used.

at the well-known from the prior art ice storage devices is usually over the lateral surface a tube symmetrically stored ice, resulting in a thickness 40mm and more can be done.

ever however, more ice is stored, the worse it develops the efficiency of the overall system, because of the higher ice volume and ice surface a higher one Discharge is necessary during defrosting. In systems in which a refrigerant is due to the higher ice thickness and ice surface one lower evaporation temperature necessary when ironing. In appropriate Way diminishes this discharge power again when the thickness of the accumulated ice decreases or the ice surface is lower becomes.

in the Unlike the ice storage devices must be in the devices for direct cooling of the energetic balance between the refrigerant and the water on the one hand and the flow rate of the discharged from the container, then cooled water on the other hand be accomplished in such a way that during operation of the device prevents the formation of ice on the lateral surface of the pipes becomes.

at the known from the prior art systems in which a Tube bundle system the container (s) However, the problem that occurred under certain conditions ice still forms on the lateral surface, because the distances between the tubes or tube bundles, between which the water flows, can be too small. This danger of freezing leads to a reduction in the efficiency and in the worst case failure of the direct cooling device, when due to the complete Freezing no more water can flow between the pipes.

outgoing from the prior art devices for both ice storage as well as for direct cooling known disadvantages, it is an object of the present invention, respectively to provide a device which for the respective application a provides better efficiency.

For an ice storage device is the corresponding object with the features of the claim 1 and for a device for direct cooling is the corresponding object with the features of the claim 2 solved.

Of the Core of the invention for both the application of an ice storage device as well as for the application a device for direct cooling is therefore the fact that the enforcing the respective container Pipe in which the refrigerant through the container guided is, is formed such that its lateral surface elements having.

at an ice storage device, these surface elements serve as connection elements for the ice, while in a device for direct cooling such surface elements as contact surfaces for the Cold transition serve the total contact area between the liquid or increase the water and the pipe.

Basically independently created a larger surface of the design of the surface elements according to the invention, what kind of Creates turbulences. By better Verwirblungen around these surface elements results in a higher Heat transfer coefficient (k-value) and thus a better heat transfer between the in the Pipes pouring Brine or the refrigerant and the surrounding water in the container.

While in an ice storage device during the charging process around a smooth tube, which in conventional Ice storage devices is used, an ice fur relatively quickly on its lateral surface trains, which the heat transfer influenced, this forms at one with corresponding profiles or surface elements provided pipe according to the invention relatively late out, with the advantage that for a longer one Duration a better heat transfer is realized.

In order to accompanied by the efficiency of an ice storage device according to the invention at comparable ice thickness much better than in a conventional system with smooth tubes. Likewise, the discharge capacity decreases during the unloading process not as strong as a conventional ice storage system, as of a certain ice thickness with decreasing ice thickness due to the connection to the surface elements the ice surface becomes wavy. However, a wavy ice surface leads to a total larger ice surface, causing the discharge capacity increases.

One Another advantage of equipped with such pipes ice storage device lies in the fact that with a comparable achievement of the space requirement compared to conventional Approximate systems with smooth tubes half as big. The energetic advantage over These systems are in the range of up to 25%.

at a device for direct cooling is the use of such pipes according to the invention with the advantage connected that the distance between the individual tubes of a tube bundle can be larger with the same power requirement, whereby the Risk of freezing is avoided.

In order to accompanied by the efficiency of a device for direct cooling according to the invention much better with comparable container size than in a conventional one System with smooth tubes. The energetic advantage over these systems is also in the range of up to 25%. With the same size can The performance increased up to 3 times compared to conventional systems become.

To For purposes of increasing performance or optimization can existing ice storage devices and devices for direct cooling, which so far Use smooth tubes without big ones renovations by replacing the pipes and installing the pipes according to the invention later converted become.

The with the surface elements provided with tubes in principle also in hybrid ice storage devices be used. In daytime operation, the device can exclusively for Direct or direct cooling be used while in night mode, the same device can serve as ice storage facility. This happens, for example, that in night mode no chilled Water dissipated more becomes. It then forms ice on the surface elements of the pipes. The device then works as latent storage, the cold energy in the form of ice can store, which then again by defrosting of ice can be delivered to the consumer network.

The surface elements extend according to the invention extending substantially radially from the outer surface of the tube to the outside in the Container. These surface elements can either over the entire tube length inside the container extend or are only partially provided on the pipe.

According to the invention can the surface elements be designed as lamellae. This can be according to the invention two different versions differ.

In a first embodiment are the fins, comparable to a finned tube, each other in parallel arrangement on the tube in the axial direction, preferably in equidistant intervals, arranged. In a second embodiment extend the fins along the tube in the axial direction and are preferably circumferential in equidistant intervals arranged.

A another possibility consists in at least one lamella spiral around the lateral surface of the To let pipe run around.

By the different configurations with slats are in use in ice storage devices correspondingly larger connection surfaces for the ice provided. To offer in a device for direct cooling These slats larger contact surfaces for the cold junction between the refrigerant and the liquid.

In a further embodiment according to the invention are the surface elements as radial projections or finger formed, which radially from the outer surface of the Pipe in the container extend.

These Fingers can in equidistant intervals arranged to each other or axially offset from one another. Furthermore can these fingers have different lengths exhibit and become undulating or spiral extend.

In a still further embodiment according to the invention are the surface elements designed as lamellae, wherein the lamellae are axial and more For this purpose, blades extend radially, so that a grid on the lateral surface of the tube which is open radially outward, wherein in an ice storage device, the ice in each section of the grid can attach.

In a particularly preferred embodiment according to the invention the container can Ice storage device or device for direct cooling in be divided into several segments. This will u. a. the block ice formation minimized, which is undesirable even with ice storage devices. A subdivision into segments leads ultimately to optimize energy efficiency in both described Systems. According to the invention can this efficiency is further increased Be different by changing the individual segments as needed designed surface elements can be equipped. This leaves along the discharge direction of the refrigerant realize a different energy distribution in the pipes.

Preferably can one or more segments in daytime operation excluding the direct cooling serve while the remaining Segments in night mode only take over the function of an ice storage.

The Invention will now be described below with reference to the accompanying drawings illustrated embodiments be explained in more detail. Show it:

1 in a side view an example of an ice storage device or a device for direct cooling;

2 a perspective view of a tube in a first embodiment for use in an ice storage device or apparatus for direct cooling according to the invention;

3 in cross-sectional view of this tube with attached ice in the full storage state in an ice storage device according to the invention;

4 this in 3 shown pipe during unloading;

5 in perspective, a tube in a second embodiment for use in an ice storage device or apparatus for direct cooling according to the invention;

6 in axial section the in 5 tube shown;

7 in perspective, a tube in a third embodiment for use in an ice storage device or apparatus for direct cooling according to the invention;

8th in perspective, a tube in a fourth embodiment for use in an ice storage device or apparatus for direct cooling according to the invention; and

9 in perspective, a tube in a fifth embodiment for use in an ice storage device or apparatus for direct cooling according to the invention.

In 1 By way of example, a construction is shown in cross-sectional representation which can be used both as an ice storage device and as a device for direct cooling.

This structure consists of a basin or container 1 which with water 2 is filled. The container 1 is divided into three zones I, II and III. Each Zone I, II and III each have a tube bundle 3 on, which consists of a single tube 4 which, in order to realize a countercurrent principle, is stacked in the container 1 is arranged.

The pipe 4 each with an inlet 5 for a refrigerant or a refrigerant from a refrigeration system, not shown, and a drain 6 in connection. For a direct cooling device, the container would 1 in turn connected to a consumer network, not shown, to which the cooled water 2 from the container 1 then fed. Instead of the water can also brine in the container 1 be used.

As can be seen, the tube bundles are located 3 always below a liquid line 7 , In the container 1 is also an agitator 8th arranged, which for better circulation of the water 2 during the unloading process.

In 2 is a first embodiment of a tube 4 shown in the in 1 shown container 1 either for an ice storage device or for a device for direct cooling can be used.

This pipe 4 serves to guide the refrigerant and has on its lateral surface 9 Surface elements in the form of lamellae 10 on.

In this embodiment, the fins are 10 arranged as circular discs, which are provided parallel to each other at equal intervals in the tube axial direction. The slats 10 are on the lateral surface 9 of the pipe 4 secured by a positive connection, preferably by a welded connection.

In 3 is a cross-sectional representation of the example of the use of the tube 4 shown in an ice storage device. In the spaces between the slats 10 and radially around this outside is ice 11 which saves the cold.

In 4 is a condition during the discharge of the ice 11 shown. Depending on the distance between the slats 10 During unloading, as can be seen, a wavy surface forms 12 of ice 11 which offers a larger surface area compared to a pure cylindrical ice surface and thus provides a higher discharge capacity.

Both this Eisanbindungseffekt desired for ice storage devices according to the invention as well as the desired for direct cooling devices cooling effect are also with a tube 4 scored, which, as in 5 shown lamellae 13 on its lateral surface 9 which extends in the axial direction of the tube 4 extend. The slats 13 are circumferentially provided at equal intervals, as is apparent from the cross-sectional view of 6 can be seen.

When used in an ice storage device can between these axial lamellae 13 During the unloading process also a larger ice surface by forming a ripple arise.

In 7 is another embodiment of a tube 4 shown for use in both types of devices. In this tube are on the lateral surface 9 Projections in the form of fingers 14 arranged, which extend radially. The finger 14 are provided in both radial and axial directions at equal distances from each other.

However, it is also possible that the fingers are radially and / or axially offset from each other. In 8th Such an embodiment is shown in which further fingers 15 are provided, which are opposite to the fingers 14 are offset radially and axially.

The fingers can on the lateral surface 9 of the pipe 4 be attached either by non-positive or positive connection.

In 9 is a fifth embodiment of a tube 4 shown. On the lateral surface 9 of the pipe 4 are both axial lamellae 16 as well as radial lamellae 17 provided at certain intervals to each other. The slats 16 and 17 intersect and communicate with each other to form a lattice structure which is radially open to the outside.

As materials for both the pipe 4 As well as for the individual surface elements, stainless steel, hot-dip galvanized steel, steel or plastic can be used. Also conceivable are aluminum, titanium or non-ferrous metals for both the surface elements and the support tube. Depending on the application, it is also possible to combine different materials for the surface elements on the one hand and the support tube on the other hand with each other.

1

container

2

water

3

tube bundle

4

pipe

5

Intake

6

procedure

7

liquid line

8th

agitator

9

lateral surface

10

slats

11

ice cream

12

wavy ice surface

13

slats

14

finger

15

finger

16

axial slats

17

radial slats

I, II, III

zones of the container

Claims (16)

Device for storing ice with a container ( 1 ) for receiving water ( 2 ) and at least one container ( 1 ) penetrating pipe ( 4 ) for guiding a refrigerant, wherein in the container ( 1 ) on a lateral surface ( 9 ) of the pipe ( 4 ) Ice cream ( 11 ) is formed when the refrigerant in the pipe ( 4 ) is vaporized, characterized in that the lateral surface ( 9 ) of the pipe ( 4 ) Surface elements ( 10 . 13 . 14 . 15 . 16 . 17 ) for ice formation. Device for direct cooling of a liquid to be cooled, preferably of water ( 2 ), for a consumer network with a container ( 1 ) for receiving the liquid from which it can be removed if necessary, to be supplied to the consumer network, and with at least one of the container ( 1 ) penetrating pipe ( 4 ) for guiding a refrigerant, wherein the liquid in the container ( 1 ) is cooled when the refrigerant in the pipe ( 4 ) is vaporized, characterized in that the lateral surface ( 9 ) of the pipe ( 4 ) Surface elements ( 10 . 13 . 14 . 15 . 16 . 17 ) for cooling. Apparatus according to claim 1 or claim 2, wherein the surface elements ( 10 . 13 . 14 . 15 . 16 . 17 ) substantially radially from the lateral surface ( 9 ) away. Device according to Claim 3, in which the surface elements ( 10 . 13 . 14 . 15 . 16 . 17 ) are provided at least in sections. Device according to Claim 3 or 4, in which the surface elements are in the form of lamellae ( 10 . 13 ) are formed. Device according to Claim 5, in which the lamellae ( 10 ) are arranged in the tube axial direction at equidistant intervals. Device according to claim 5, in which the lamellae ( 13 ) extend in the tube axial direction. Apparatus according to claim 7, in which the lamellae ( 13 ) are arranged in the tube radial direction at equidistant intervals. Apparatus according to claim 6, 7 or 8, wherein the lamellae spiral around the Mantelflä che ( 9 ) of the pipe ( 4 ). Apparatus according to claim 3 or 4, wherein the surface elements as radial fingers ( 14 . 15 ) are formed. Device according to Claim 10, in which the fingers ( 14 . 15 ) are arranged at equidistant intervals. Apparatus according to claim 10 or 11, wherein the fingers ( 14 . 15 ) are axially offset from each other. Device according to Claim 10, 11 or 12, in which the fingers ( 14 . 15 ) are wavy or spiral-shaped. Apparatus according to claim 3 or 4, wherein the surface elements by axially extending slats ( 16 ) and radially extending lamellae ( 17 ) are formed to form a radially outwardly open grid. Device according to one of claims 3 to 14, in which the container ( 1 ) is divided into several segments (I, II, III). Device according to Claim 15, in which the surface elements ( 10 . 13 . 14 . 15 . 16 . 17 ) are formed differently in the individual segments (I, II, III).