WO2002039028A1

WO2002039028A1 - Layering pipe for distribution and storing of liquid

Info

Publication number: WO2002039028A1
Application number: PCT/SE2001/002441
Authority: WO
Inventors: Stefan Larsson
Original assignee: Vattenfall Ab
Priority date: 2000-11-09
Filing date: 2001-11-07
Publication date: 2002-05-16
Also published as: SE0004092D0; DE10196807T5; DK200300632A; SE0004092L; SE516937C2; AU2002212930A1

Abstract

The invention relates to layering pipe for distribution and storing of an incoming liquid with an arbitrary temperature in a storage tank intended for said liquid in which the stored liquid is layered at different temperature levels due to differing densities. The layering pipe (7) comprises an outlet opening provided with a check-valve device which allows an outflow of liquid into the tank but prevents an inflow from the tank into the layering pipe. The outflow opening is in the shape of an elongate opening or slot (8) extending in the longitudinal direction of the layering pipe (7) and along essentially the whole length of the layering pipe. The check valve device comprises an elongate, flexible element (11), which is fixed relative to the layering pipe along a line or an area parallel to the longitudinal extension of the outflow opening and which overlaps the opening from the outside of the layering pipe. According to a preferred embodiment of the invention, the layering pipe further comprises a deaeration and throttling device.

Description

LAYERING PIPE FOR DISTRIBUTION AND STORING OF LIQUID

The present invention relates to a layering tube or pipe for distribution and storing of an incoming liquid with an arbitrary temperature in a storage tank intended for said liquid in which the stored liquid is layered at different temperature levels due to differing densities, the layering pipe being intended to extend vertically through the liquid stored in the tank and comprising an inlet end and an outlet opening provided with a check- valve device which allows an outflow of liquid into the tank but prevents an inflow from the tank into the layering pipe . Background of the Invention

In heating systems, it is common to use accumulator tanks to store a heating medium in the form of a liquid, usually water, and thus to be able to store thermal energy from periods of production surplus to periods of production deficit. From the point of view of energy, it is important that the incoming water be stored at the right level in the tank so that thermal stratification is achieved, hot water being located in the upper part of the tank and cold water in the lower part of the tank. If satisfactory thermal stratification is provided, it is possible to obtain a considerable temperature difference between the cold water at the bottom of the tank and the hot water at the top. In this way, it is possible to obtain a highly efficient heating device, since the water to be heated, which is brought up from the bottom of the tank, is heated starting from a low temperature level. Furthermore, the degree of utilization of the accumulator tank will be high if the water at the top of the tank, from where it is supplied to the places of consumption, for instance for heating purposes, has a high temperature . Typically, the heated water from the heating device is supplied to the upper part of the tank. This is satisfactory in cases where the water is always heated to a high temperature, as is the case with, for example, solid fuel boilers or oil boilers. In some other cases, such as solar heating systems, a certain degree of net heating takes place during certain periods but the water may not always be heated to a temperature equivalent to or higher than that of the water stored in the top part of the tank. If this water, the density of which is higher than that of the surrounding water, is supplied to the upper part of the tank, it will sink towards a level with the same temperature. A vertical circulation and mixing of the water in the tank thus occurs, which may undo the thermal stratification in the tank and lower the efficiency of the heating device as well as the degree of utilization of the tank.

In prior-art devices, attempts have been made to eliminate these problems and drawbacks in order to allow storage of the heated, incoming water from the heating device at the right temperature level in the accumulator tank. EP 384,423 discloses, for example, a device of the type mentioned by way of introduction, which consists of a layering pipe extending from the top of the tank to its bottom and presenting along its length a number of horizontally oriented outlet pipes . Each of the outlet pipes comprises a check valve which allows water to flow from the layering pipe and into the tank but prevents it from flowing in the opposite direction. It has been found, however, that this layering pipe gives relatively small improvements in the thermal stratification in the accumulator tank. This is probably due to the fact that the flow into the accumulator tank takes place at certain points and that the water often flows out through two or more outlet pipes at the same time. It may be the case that the right temperature level for the water coming from the heating device is located between two outlet pipes and water will then flow from at least the outlet pipes that are located immediately above and below the right temperature level. This will cause a vertical circulation in the accumulator tank as a result of the differing densities. The vertical circulation may influence a large volume of water in the accumulator tank and thereby lead to impaired thermal stratification. Causing the liquid to flow into the tank through one or a few outlet pipes with a relatively small diameter further implies that the velocity of flow will be relatively high, which will further enhance circulation and mixing of the liquid in the tank.

It is also a trend in the field of solar energy to use smaller pipe dimensions in the solar heating systems and to circulate the heating medium or water at a higher velocity. The purpose of this is to reduce the heat losses in the system, since small pipe dimensions mean a smaller cooling area. However, the increased velocity of the water also means that the water flowing into an accu- mulator will have the character of jets, which may extend far into the water volume of the tank and thus undo the thermal stratification in the tank. Summary of the Invention

The present invention aims at eliminating the prob- lems and drawbacks mentioned above and creating a layering pipe which has a simple structure and is inexpensive to manufacture and which provides improved thermal stratification in an accumulator tank by incoming liquid being fed to the tank at the right level of temperature without causing any vertical circulation or mixing of the liquid. At least these objects are achieved by means of a layering pipe according to claim 1.

According to a particularly preferred embodiment of the invention, the layering pipe also comprises a deaera- tion and throttling device for liquid supplied to an accumulator tank, which is simple and inexpensive to manufacture and has a long life and which is capable of

Ω 0 C^Q Φ rt H- l-" rt =^> SD Hi rt rt SD rt $ 3 if Hi CQ rt rt 0 Ti rt rt Ω SD 3 CQ ι_ι. Φ

H- i-J SD ϋ if a 0 tr H- SD tr μ- 4 μ- Φ if SD Φ ii SD tr tr 13 H μ- fβ tr ϋ μ- rt Φ o Hi

H φ rt H- φ CQ sS φ r CQ Ω Φ O Φ Λ -E. Φ rt SD O rt Φ Φ φ μ- O <! Φ SD φ 0 rt

H- μ- rt •z Hi

Ω P tr H- rt H ti SD S3 Ό ii 3 Φ 0 ti Φ μ- μ- μ Φ μ-

C 0 CQ CQ CQ 0 <l a φ μ- Φ φ Ω Φ Ω £ Φ μ> CQ 3 SD 13 φ Φ μ Ω μ Hi t H Hi φ H- rt CQ rt tr SD £ ' ϋ SD rt if if rt rt Hi Ω CQ Pi Hi μ- μ-

SD SD Ti SD i-i μ- ' Λ if tr ^■<: ti μ- SD rt tr Hi Φ 0 0 SD tr μ- 0 if -^j if Hi P Φ

H C^Q Ω H- Ti rt o ø φ φ SD Si rt rt if - Φ Ω 13 H Φ 13 H μ- μ- O SD φ CQ

Φ rr TS φ 3 t Ω H- _^ rt SD a if CQ S3 Φ *<! μ- φ Φ CQ rt ii SD CQ Φ Hi rt Ω rt tr <! 0 Φ 0 Φ H- & H tr μ- H sQ 0 <! SD Φ SD CQ <! rt rt

0 φ ϋ - 0 CQ rt H- ii SD S3 rt 13 Φ tr C S3 μ- < rt tr μ- 13 Φ μ- Φ rt rt if ^■<: ii ^ Hi rt *< £ CQ φ o H> t Ω μ- φ μ- rt tr SD Φ Φ * 13 φ SD a Pi if if 3 φ φ SD H H- H- tr (-^■ Ω ^ CQ φ Λ CQ 13 SD 0 <! Φ Φ SD K

CQ h-> ii ft SD Ω Λ l-¹ rt SD tr μ- μ- 13 S3 CQ μ- φ < CQ O Ti 3 Ω Hi Φ tr <! φ

^•» Φ SD 0 3 ¹ rt Φ i-J tJ ii rt & μ- rt Hi P- Φ rt TJ H SD Ω 13 < μ Φ 3

H CQ £ Ω CQ H- tr rt H- Ω CQ CQ μ- if •• ϋ 0 Φ φ if Φ 0 > 13 μ- rt μ- μ- tr 0

3 0 (3 0 0 Φ & H- Hi Φ CQ Φ H 0 ϋ 13 <! 3 13 μ- 3 tQ CQ φ 0 <! if I-¹ ø i-J CQ • Ω 3 φ rt 0 tr el^¬ μ- φ :> 0 φ Φ 0 μ- μ- tr S3 Ω O φ C if Ω μ-

H- n rt l-¹ rt - tr 0 Ti < t Hi rt s' V P. μ- Hi 3 Hi ts P. φ 0 tJ SD μ- rt TJ μ-

Ω a p. H- £ Φ ^ SD φ μ- 13 13 Φ μ- CQ μ- SD 3 13 ii rt CQ tT 0 tr 0 H- Hi ϋ rt rt μQ C^Q rt SD CQ rt ti Ω rt i3 CQ rt μ- μ- CQ rt φ ^

Hi ^ tr ø rt 0 H- SD < if Φ S3 - tr rt tr rt φ tr 0 CQ μ- 0 13 CQ μ- Φ <! i

SD Φ O ii tJ rt SD Φ μ- Φ 3 μ- φ μ- φ Φ ii Q H CQ 0 13 3 Φ 0 μ- i rr τι ø μ- rt rt 0 ii μQ TJ P. rt rt 13 Ω μ- SD 13 tr Hi Ti 13 Hi CQ

Φ H- H TS CQ CQ if 0 ϋ CQ O S3 Hi φ 13" SD tr rt 0 13 CQ μ- rt M SD rt Φ rt CO

CQ o 0 Φ Φ Φ Hi μ- H 13 Φ Ω Φ 0 SD <! SD Hi SD μ- CQ SD if 4 Φ rt 0

Ω tr CQ O 13 ii rt Φ SD SD Ω ^ Φ r ^ O SD μ- i-J Λ φ Φ SD i if

O rr H- CQ TS ii t Ω rt X rt rt C^Q 13 ii SD Φ ii tr Φ rt ^ Ω S3 ϋ H rt Φ <1

<! . H- Φ φ Ω Φ Φ o tr rt μ- 3 1 SD 3 μ- 13 ii H- Φ H Φ SD μ- SD rt C $D φ φ ^ H- tr i-J Hi 0 <i a H- 0 σ ii H 3 S3 Q μ- ti μ- Φ ϋ P SD P. o • ! SD μ 13 μ- p. ϋ s H- φ C rt Φ rt CQ Φ D φ tr SD 13 CQ Hi 13 X μ- rt !3 i-J φ a Φ Si i-J

Φ CQ CQ φ P H - SD I—¹ H- Hi φ SD rt Ω CQ o cQ rt 13 a SD ϋ Ω CQ . TJ Q H rt a ϋ Ω μ-¹ , rt Ω SD ii Φ CQ ^ rt rt μ- μ- O SD

SD SD φ Φ S 0 0 φ Φ ^ Φ O (3 Tf 13 3 •d 13 rt if 13 Φ tJ 3 CQ tr Ω T H- i H Hi 0 a s; 13 H Φ 3 μ- i μ- ϋ Ti μ- tr rt Φ CQ < Ω μ-

^ Φ CQ o 0 SD SD 0 S3 CQ φ Φ Hi C^Q <! S3 * 0 ^■n μ- μ- 3 Φ if rt Φ 0 13 Hi

& t, Hi Ω rt K CQ rt μ- 3 μ- μ- rt Φ μ- φ 0 Hi Φ 13 Ti I Φ Si Ti 3 CQ μ,

SD 0 φ rt 0 rt rt H tι φ 13 rt SD SD • < CQ φ H rt ti μ- μ- o tT rt tr K CQ SD tr 0 13 rt 13 SD ϋ ^ 13 rt Φ SD SD 0 tr μ ϋ Tl Φ i-J a 3

Ω O φ Φ φ Ό Ω O rt 13 ? 0 H 4 rt 13 SD tr <; Φ μ- φ Φ SD μ- CQ μ-

0 H- ϋ rt S ϋ φ rt ϋ μ- SD μ- ii 13 Si SD φ μ, CQ ii CQ rt Λ rt

3 Φ V - $ tr a SD 0 H- rt μ- rt CQ tr • SD 0 < Si 3 if CQ SD rt tr C if

3 CQ SD Φ a ^ςf Φ H- 0 i ϋ Ω C^Q SD Φ rt rt Ti Φ tr 13 μ- SD rt rt Ω 0 μ- μ- Φ

0 rt rt V-¹ < a 3 P Φ S rt CQ • SD tr Ti SD ^ CQ 13 μ- H SD Ω rt S3 μQ ϋ t 0 CQ Ω SD CQ CQ rt ≤ if 13 μ- μ- CQ CQ 13 rt ti 0 if rt C

Hi φ φ a 0 s; rt if CQ SD Φ rt rt CQ 13 rt Ό Φ CQ Φ Si ϋ Φ μ- CQ μ-

0 O 0 0 CQ rt K P- H- SD μ- Φ ^ tr if CQ H CQ SD μ rt 3 μ- Si CQ 13 α o μP

Hi ii Hi tr Hi rt CQ SD φ ti t-^> i-S n μ- φ Φ t, 0 0 CQ rt Φ H Ti 13 μ- φ 13 S3

0 rt SD CQ CQ h-¹ ? ϋ rt 13 μ- SD rt 13 <! Φ SD Φ CQ 13 13 3 rt μ-

Φ Φ ii PJ rt rt ϋ Φ rt SD Φ 0 Ω CQ • : tf Φ μ- ti -> SD rt μ> CQ 0 Φ SD tr ϋ

X X 3 H- if 0 ^ 0 rt tr Si H Hi 0 SD Φ Φ Si rt φ rt μ- SD rt tr Ω •<; SD

H- S 13 φ C tr Φ φ 1-3 φ 0 rt 3 3 <1 Φ μ- μ- ?D μ- Hi rt tr rt Φ rt SD tr 3 o tr 3 CQ D Hi tr SD ii tr μ- φ Φ SD rt CQ 13 SD CQ 0 μ- S3 SD O φ CQ tr

TS Hi SD SD H- -~ rt SD H- Φ - ø

3 φ 13 \-> C if 0 CQ rt ti Ω ii rt Ω CQ Φ SD ϋ

Φ < •^ ϋ tJ SD CQ rt Φ 0 13 SD Φ rt SD !3

Φ Φ 1 φ Φ 1 0 rt rt 1 CQ i

1 SD 1 O

element . Such a design would probably give rise to an unfavourable turbulent flow around the edges of the holes, but provided that there is a sufficient number of holes and that they are tightly spaced, the flow charac- teristics could be adequate for most applications. It is also preferred, above all because of the expense, for the layering pipe to be provided with only one slot, but it would, of course, be possible to have two or more slots along the circumference of the layering pipe, for in- stance four slots arranged at an angle of 90 degrees relative each other. Naturally, the layering pipe need not be circular in cross-section, but could be square, for example.

In the claims, it is stated that the slot extends along essentially the whole length of the layering pipe. Here, length of the layering pipe means the part of the layering pipe that is normally intended to be submerged in the liquid volume in the accumulator tank. In addition, the layering pipe may have an upwardly extending connecting part which cannot be considered to form part of the actual layering pipe. Moreover, the slot may end at a suitable distance from the lower end of the layering pipe, while the upper end of the slot may start at a suitable distance from the upper end of the layering pipe.

The check valve can also be designed in many different ways within the scope of the invention. In most cases, it is preferred that the flexible element comprise at least one continuous flexible element which extends along the entire length of the slot. It would also be conceivable to provide a flexible element that is made up of two or more flexible element parts which are arranged edge to edge along the length of the slot. However, the result would probably not be as good. For the flexible element to function as a check valve in the way it was intended, it has to be fixed relative to the layering pipe along a line or an area

CQ μ- SD Φ φ CQ <i Φ Hi rt i 3 CQ Hi £ rt Hi φ rt ø 3 Ω Φ CQ μ- μ- ii tr ϋ CQ Hi if Ti

3 CQ 0 μ^j μ-* 0 SD 0 Φ ø SD tr ii if if μ- Φ tr 4 Φ ii Ω ø ø CQ 0 μ- μ- 0 ø

SD Φ φ Ω ii Φ ϋ ø tr rt φ Φ μ- Φ X φ ø Φ ϋ rt O 0 ii ^ cQ ø CQ ø 0 Φ CQ ii

TJ μ- 3 3 if μ- 3 Ω Si tr Φ φ Φ ^ φ 3 CQ ø ø CQ 0 μ- Φ 4 0 tr ø rt X ø ø Φ φ 0 φ φ Φ Φ μ rt φ Pi φ rt if 0 CQ CQ tr i Ti Φ i Φ - μ- rt μ^j

Φ μ- ø ø SD ø ø Pi ii μ- H • SD SD ø 0 CQ 0 Φ H μ- μ- 3 μ- ii tr 0

Pi CQ rt rt rt CQ CQ rt 3 • SD tr ø rt tr ø rt ø μ-* Φ CQ CQ rt Pi 0 ø Ti 0 ø Φ ø Φ

Φ rt μ- if φ tr 0 CQ CQ Φ Pi tr Φ Φ CQ Φ <! CQ TI pi 0 φ Ω

CQ ii SD tr 0 3 => rt μ- μ- ^ ~ φ rt 0 φ Ω tr 0 φ ii CQ i 0 ii Φ Φ μ φ SD 0 Ω rt 0 Ω SD μ- 0 ø ø μ- φ rt 0 Φ Ti rt Pi ø Φ Φ φ < rt

Φ CQ μ- rt ^ =^> if ii CQ tr cr μ ø CQ ii ø ii ø rt μ- Ti Ti μ- 0 Ω CQ μ- Φ 0

Φ CQ ^ ø SD SD CQ SD CQ 0 Φ 0 CQ Φ ii Φ O Φ 0 μ Ti Hi n CQ CQ rt φ μ φ Q TJ h-¹ _^ ti μ- tr rt Ω Ω rt μ, ø 0 CQ ø rt Ti ø 0 g; φ φ Hi 0 0 0 3 rt

0 Pi CQ Ti ϋ ø 0 if tr ? φ μ- 0 ø Φ tr ϋ μ- Hi 0 0 3 ii tr φ rt tr

Hi 3 £ Hi CQ 0 φ SD CQ ø Φ μ 0 φ 0 ø φ 0 μ 3 0 Φ rt 0 ø tr φ μ- μ- 0 μ- μ- 0 SD SD < CQ Ti CQ μ ø Hi <! > CQ rt μ ø 3 tr CQ rt Φ

TJ ø CQ 0 φ ii ii rt P. Ω CQ SD SD φ rt 0 0 Q 0 μ- ø tr 4 rt rt 0 μ- 0 co μ tr ø Pi φ if CQ tr μ- o Hi ø rt 4 i Hi Φ Φ SD if rt rt rt CQ rt rt rt ø 0

Φ CQ μ- Φ Ti T! Φ SD <! ø rt rt CQ rt tr Φ Φ ø 0 Si μ- Φ 0 _^ 0 PJ ø

CQ tr Φ Hi _^ ø ϋ 4 Ω φ CQ μ- tr rr Φ if φ 0 ø μ CQ ø ϋ rt o CQ rt Φ ; Pi ii CQ CQ μ- Φ ? CQ rt <i Φ tr Pi Φ CQ 3 Φ rt μ- 0 if £ T! 0 rt μ- ϋ _^ 0 rt rt ø CQ tr ϋ φ Φ CQ 0 £ Φ 0 3 0 μQ 0 φ if H ø rt

Φ p. tr 3 tr SD 0 CQ φ < Φ φ Φ 0 μ- 0 O tr 0 μ- Φ Pi rt y ø rt μ- Φ Φ CQ tr 0

CQ μ- Φ SD SD ø rt 1 0 SD Φ < SD 0 0 H ø Ti Φ rt rt o rt μ- Φ μQ ø CQ ^ Pi

CQ μ ø CQ rt rt Ω tr rt rt μ- Ω T rt φ Φ CQ tr Φ μ- if Pi tr ti 0 ø Φ rt μ-

Φ rt tr Φ 0 SD <! Ω if Ti CQ h-¹ tr 0 rt μ- ø 0 μ- Φ μ- ^ μ- 0 if μ- ø μ- Ω μ- φ SD Ti Ω SD φ 0 Φ 0 μ- 0 0 μ- Pi 0 Φ CQ 3 Ti Φ i Φ rt rt Φ rt ø ø rt CQ ø i tr Φ w Hi 0 CQ Pi 0 rt 0 3 Φ 3 rt φ 0 0 μ CQ μ- rt 0 Φ ^ 0 CQ Pi - 3 rt μ- Φ CQ tr Q Φ ø φ tr rt ø μ- CQ <! μ- μ- ø £ φ rt 0 SD rt 0 μ- 3 3 φ SD tr rt rt rt 0 ø φ if rt μQ CQ Φ rt ø CQ rt if Φ tr ø rt if rt Φ CQ ø SD SD <! Hi •^• Φ Φ 0 CQ CQ ø ø tr 3 rt φ ø 0 tr CQ o Hi X φ Φ Φ CQ |3 Ti CQ ø μ- 0 ii Hi μ- μ- ii Φ cj¹ s: 0 μ- CQ 0 φ Pi rt

0 μ- ' Φ • ø Ω μ tr i Pi Φ Φ μ- 0 CQ Hi P. φ TS TJ Φ Φ Φ o Φ ϋ Hi CQ Ti Pi Φ Ω Φ Φ Φ μ- 0 rt Φ φ ø CQ CQ ii ø if Φ Hi μ- Hi ø μ 0 μ- 0 H Φ ϋ μ- H ii ϋ Φ ø 0 if CQ CQ φ 0 rt < Hi Ti 0 CQ £ CQ μ rt Φ - ϋ SD if φ rt X 3 CQ Φ 0 Ω 0 0 rt TI if 0 ϋ CQ Φ Φ μ rt μ- rt μ-

Φ if rt Hi Φ μ- 3 CQ 0 SD SD rt μ- rt 0 Hi rt rt Hi if 0 φ Φ 0 ø Φ 3 0 0

Ω φ tr Φ 0 Pi CQ 0 ti 3 Pi tr rf CQ O Hi μ- Φ Hi ø 3 μ - rt Φ 0 rt CQ 0 rt SD ϋ ii 4 < φ Hi T φ φ ø tr rt 0 μ- rt 0 μ- 3 Hi if p. 0 tr Φ μ- CQ rt ϋ μ- Φ 3 Φ Φ ø i Φ rt rt if 0 0 if Hi 0 Hi ø Φ rt 0 0 Φ rt 0

0 Φ tr ø CQ SD CQ ø φ o SD μ- Φ tr if φ μ 0 <! tr Ω 0 0 SD 0 tr Hi

0 0 s; ϋ ^ μ- ^ 0 Ω "« Hi μ ø rt Φ Φ μ- CQ 0 μ T SD φ O φ Φ 0 CQ Hi ø φ rt tr rt rt Hi rt Φ CQ CQ ø ø 3 μ- ø Hi CQ μ- ti P. H rt

0 Φ Φ rt tr μ- tr if μ- Ti SD SD 3 CQ Ω CQ T Ω rt μ- 0 μ- ø 0 Φ tr

Hi 0 ø 3 tr Φ φ φ φ TI 0 0 Φ 0 if 0 Ti tr tr 0 Φ 0 μ- rt ø Hi rt Φ € Φ

Ti rj" Φ ø μ 0 SD ^■ ! 0 Φ rt ^>< Φ rt H Hi 0 O tr CQ ø rt ii φ μ- rt Φ 3 0 Hi rt SD Hi φ CQ 0 Si ^ Φ Φ Φ 3 tr O rt ø Φ μ- rt ϋ if φ 0 rt CQ tr 0 0 i Hi r-¹ Ω CQ SD rt Hi rt Q 4 rt Hi 0 0 ø Hi μ- "• Pi tr μ- Φ CQ 0 CQ tr

Φ μ- ø μ- Φ Φ if Φ rt CQ μ- CQ Φ μ- ^ Φ ø ø rt Φ φ 0 0 0 rt 0 ø 0 3 Φ X μ- X μ Ω Φ μ- C^Q CQ ø SD μ ø φ tr Ω ø ø ø 0 CQ μ^j CQ tr 0 rt

CQ CQ rt φ X μ- Φ φ μ- φ μ- X Pi Φ CQ 0 φ 0 Φ CQ Φ μ- 0 CQ 0 O 0 rt μ- rr

• Φ ø μ- tr 3 <! tr CQ ø O μ- φ H Ω i X tr H ø ii ø W Hi 0 ii rt o if

0 Pi rt tr Φ φ CQ 1 4 tr Φ rt Ti μ- μ- rt Ω CQ Pi ^ Φ 0 0 Hi φ μ- rt > φ 0 i φ H- rr 3 μ- μ- tr rt CQ ø φ rt φ Si Hi ϋ rt μ- φ rt 0 Φ tr ø 0 Ti if 1 tr μ CQ rt rt μ- CQ μ- CQ φ μ- ø φ φ 0 0 ø φ 1 Φ ø tr ø ø ø rt rt ii Φ

opening is all that is required since as little counter- force as possible should be exerted on the outflowing liquid. A certain degree of prestress is necessary, however, in order to prevent the incoming liquid from leaking out unintentionally and being stored at a level above the level in the tank at which the liquid has the same temperature as the incoming liquid. Below this level, the surrounding liquid having a lower temperature and, thus, a higher density exerts a pressure that pre- vents the outflow of liquid from the layering pipe into the accumulator tank.

A layering pipe according to the invention can be used for many different purposes in a heating plant and not only to supply heated liquid from a solar heating system to an accumulator tank, as described above. It would be possible, for example, to use such a layering pipe to recirculate radiator water which has been circulated for heating purposes through the radiator system of a building. Typically, the radiator water is recirculated to the bottom of the tank but, although the temperature of the water has been lowered as a result of the heat dissipation in the radiators, it is not certain that the temperature is as low as it is at the bottom of the tank. Thus, by using a layering pipe according to the inven- tion, recirculated radiator water could be stored at the right level in the tank resulting in an improved thermal stratification.

It would also be possible to use the layering pipe to supply heated water from a combustion boiler to an accumulator tank. During a combustion phase when the tank is charged, the temperature of the water from the combustion boiler is high, typically 80-100°C, and it is therefore stored at the top of the tank. When combustion ceases, the residual heat in the boiler and the piping could be preserved and stored at the right temperature level in the tank by using a layering pipe according to

body in the form of gas bubbles that will gradually grow in size to finally leave the surface and evaporate as gas that can be discharged from the heating system.

To obtain a throttling effect, the area of the flow- restricting passage of the device should be smaller or, at most, equivalent to the cross-sectional area of the inlet pipe. The device further comprises two chambers, one upper chamber located above the middle portion of the spool -shaped body and a lower chamber located below said portion. The upper chamber communicates with the ambient atmosphere by the intermediary of a pressure-equalizing passage. Owing to this design, the velocity of the incoming liquid from the inlet pipe, said liquid having typically a high velocity of flow, will be reduced by the flow-restricting passage between the pipe portion and the middle portion of the spool-shaped body. Thus, the upper chamber will function as an equalization storage with a pressure that corresponds to the ambient atmospheric pressure. Thereby, the velocity of the liquid will be reduced in the upper chamber by the flow-limiting passage, since the area thereof is smaller than or equivalent to the cross-sectional area of the inlet pipe, and an open liquid surface will form in the upper chamber. Owing to its design, the device will be self-regulating so that an open liquid surface and, above said surface, a gas volume can be maintained in the chamber at all times, since the liquid throughput will be small when the liquid level in the upper chamber is low, but will increase as a consequence of an increased liquid pressure as the level in the chamber gradually rises. Once the fluid has passed the flow-restricting passage between the pipe portion and the middle portion of the spool-shaped body, the liquid will follow the lower tapering part of the spool-shaped body to the liquid surface of the accumulator tank. This should not be located at a lower level than the lower tapering end of the spool-shaped body, since it is advantageous if the tapering end is submerged in the accumu- lator liquid to avoid a free fall of the liquid the final distance and increased oxygenation and vigorous mixing of the accumulator fluid that would follow.

To prevent the liquid from falling freely towards the liquid surface as it follows the lower part of the spool-shaped body, the acute angle must not be very wide. As a rule, the acute angle should be smaller than 40 degrees, preferably smaller than 30 degrees and, most preferred, smaller than 20 degrees. The acute angle of the upper part of the spool-shaped body is not as critical and can be considerably more obtuse. However, a small acute angle is advantageous also in this case since the surface of the spool-shaped body increases as the acute angle increases, which is favourable in that it implies an increased gas separation capacity. As a rule, however, the upper acute angle should be smaller than 60 degrees, preferably smaller than 50 degrees and, most preferred, smaller than 40 degrees. Furthermore, the spool-shaped body is advantageously arranged in such manner that the upper tapering end is located adjacent to the mouth of the inlet pipe in the upper chamber so as to allow the liquid to be guided and distributed around the spool- shaped body immediately after it has entered the upper chamber . According to an embodiment of the invention, the spool-shaped body is circular in cross-section and coni- cally tapering on both sides of the middle portion. Correspondingly, the pipe portion in which the spool-shaped body is contained is circular in cross section. This is preferred since such shapes are easy to make. It would be possible, however, to accomplish the invention also by means of other shapes, for example a square cross section or a tapering portion on the spool-shaped body that is not conical but concave or convex as viewed in cross sec- tion. Brief Description of the Accompanying Drawings

In the drawings Fig. 1 is a cross-sectional view schematically illustrating an example of the structure of a heat- ing system comprising an accumulator tank having a layering pipe according to the present invention; Fig. 2 is a cross-sectional view of the layering pipe of Fig. 1 in a closed position; Fig. 3 is a cross-sectional view of the layering pipe of Fig. 1 in an open position; Fig. 4 is a cross-sectional view of an alternative embodiment of the layering pipe; and Figs 5-6 are cross-sectional views of two different embodiments of a deaeration and throttling device according to the invention. Detailed Description of Preferred Embodiments of the Invention

Fig. 1 is a schematic illustration of a possible em- bodiment of a heating system, which comprises a layering pipe having a deaeration and throttling device according to the present invention. Reference numeral 1 designates any type of heating device, such as a solar collector, which comprises a heat exchanger or absorber 2 for trans- mitting the thermal energy produced in the heating device 1 to a heating medium in the form of a liquid, usually water. Reference numeral 3 designates an accumulator tank in which the heated heating medium is stored. A pump (not shown) provides circulation of the liquid in the heating system, from the bottom of the tank 3, where it is coldest, through an outlet pipe 4 to the heat exchanging device 2, and from there in its heated condition back to the accumulator tank 3 through an inlet pipe 5. Instead of supplying, in the normal way, the liquid to the top of the tank, said tank comprises a layering pipe, generally designated 6, the purpose of which is to store the incoming liquid at a level in the liquid volume of the tank with the same temperature as the incoming liquid.

Fig. 2 is an enlarged cross-sectional view of the layering pipe of Fig. 1. This includes a circular pipe 7, in the pipe wall of which an elongate through opening or slot 8 is formed which extends essentially along the whole length of the pipe and which is provided with a check valve device. The width of the slot can vary due to the circumstances but is typically about 40 to 60 % of the inner radius of the pipe; in the embodiment shown, the width of the slot is about 50 % of the inner radius of the pipe. In the area outside the slot, the layering pipe is provided with a bent sheet metal section 9, in the walls of which a large number of small through holes 10 have been made. In most cases, it is preferred that the total hole area be at least as large as the area of the slot 8 or larger. Flexible elements 11, preferably of rubber or plastic, are arranged on both sides of the sheet section and on the outside thereof, said flexible elements being mounted in an initially bent state. More specifically, clamping bars 12 are provided on both sides of the slot, said bars being fixed to the pipe 7 by means of screws and clamping both the sheet metal section 9 and a longitudinal edge of each of the flexible elements 11 to the outer wall of the pipe 7.

As shown in the figure, each of the flexible elements 11 extends further in the horizontal direction than the outer tip of the sheet section 9 and by mounting each of the flexible elements 11 in a bent state they will, owing to their inherent elastic rigidity, abut on the one hand against the outside of the sheet section 9 and, on the other, with their free terminal edges against each other.

Fig. 3 illustrates what happens when heated liquid enters the layering pipe at the level in the tank where the liquid has the same temperature as the incoming liquid. Here, the liquid pressure on the outside of the ω u> t c μ> en o en o en o en ø t 0 0 μ- Hi 0 rt Hi ø Ti if rt Hi CQ Hi > Hi

0 Φ ø ø ø Ω 0 tr tr 4 SD if Φ rt

Pi rt Ω rt CQ Φ tr ^•<; Φ Φ 0 φ CQ μ- Φ Ω φ φ

£ 0 CQ μ- X μ- Φ X <j CQ ø X rt X rt X μ- Φ <! μ- Pi μ- φ ti μ- Φ CQ tr μ- μ- μ- if μ- ø Φ Φ Pi φ σ < μ- Φ tr 0 Φ CQ σ 0 tr ø tr rt 0 ii Φ CQ φ ø < rt μ Φ if ø rt

0 Φ φ Pi CQ Φ Φ if Φ ø Φ Φ CQ φ φ rt Pi 0 0 Φ Φ rt 3 tr Hi Hi φ tr Ti φ μ- 0 rt Φ CO φ O φ tr Φ ø *< μ- μ- Ω 0 <i 3

Φ 0 rt rt φ Ti ø φ 0 CQ Φ 0 Φ μ- φ Φ φ Q Pi if if 3 rt Φ 3 ϋ μ- ii Hi 3 CQ rt 3 0 3 tr Φ φ φ tr • rt φ ϋ Ω φ φ rt φ ø Φ 0 Φ if ø Φ φ 0 μ ø rt ø •> ø

0 φ μ- CQ Hi rt > Φ rt CQ 3 0 rt if rt rt

X rt μP tr CQ 0 CQ CQ J rt Φ tr CQ Φ CQ rt CQ

0 Φ φ ø rt 0 tr - tr - tr

CQ μ- Φ X tr rt μ- ø £ ø Φ Φ μ- -¹ Φ H

Φ Pi rt μ- Φ Φ 0 μ- Si S H £ ø H^{1 1}

Ω tr μ- ϋ X μ- if if tr o rt 3 CQ ø ø ø SD μ- o μ- φ 0 ø £ μ- ø Φ Φ CQ CQ £ CQ ^• Ω 4 Ω ti CQ μ-

0 ^ Ω Hi rt μ- tr φ if if φ 0 ^•<; -~ ø rt Φ CQ μ μ rt Φ Ti ti Ti ø μ- ¹

Hi μ- φ Φ 0 tr 4 μ- μ- μ- rt ø Hi

SD μ^J 0 Φ Ti Φ rt Φ ø CQ ø CQ CQ 0 tr

0 0 3 ø Φ rt o CQ CQ CQ Φ rt ϋ Φ

0 £ φ 4 ϋ if Ω CQ rt rt H Ω

0 U3 ø ø 0 Φ 0 ø Ti tf μ- Φ ø rt Φ rt

P. 0 rt rt ø μ- t μ- Φ Ω CQ if tr ø CQ CQ Φ CQ ø CQ φ TS • ø rt Φ ø φ rt rt 0 Pi μ- 0 ^ Φ Ω rt μ- Ω if tr rt rt 3 μ- 0 ->! μ- Ω 0 rt CQ φ rt rt Φ Hi ø if Φ Pi ø tr CQ tr <! ø μ- ø if if μ- ti Pi Φ Φ 0 φ φ Φ ti rt 0 3

Hi ti ø ø 0 μ- rt Hi rt CQ ø μ- CQ CQ φ

H 0 rt CQ 3 ø Hi Φ 0 tr £ ^ CQ μ-

Φ ø 0 μ- 3 ii Φ ii if rt μ- Pi rt ø

X CQ rt CQ Φ CQ Ti 3 μ- Φ if CQ Pi Φ 0 CO μ- t tr φ ø ø φ φ rt CQ ø μ- 3 μ- tr Φ Ti Ω φ ti μ Pi ø φ CQ ø rt 0 Ti 0 rt ø if Pi Φ 0 0 ø rt ^ Hi ii 0 φ if tr H CQ rt μ- tr Ω φ

Φ 0 ø 0 φ ø ø CQ Φ 0 rt CQ rt φ μ rt rt CQ rt t O μ- Hi tr CQ tr tr φ Φ if if φ rt rt μ- tr CQ ø Φ Φ φ 0 CQ Pi Φ 0 μ- tr tr CQ ^■^ μ- rt rt

3 ti Hi CQ SD Φ φ tr ø SD tr 0 tr μ- φ Φ H¹ Hi CQ rt ii CQ φ ø Φ ø ø CD o μ. ø rt μ- 0 0 CQ CQ CQ rt 0 0 tr CQ μ- ii ^ CQ Hi o μ-

CQ μ¹ SD 3 Pi Φ ø Φ rt 0 Hi φ i o μ, SD 0 μ rt φ μ> - Φ rt rt rt rt Ω . μ> tr tr if O μ- Φ

Φ Φ Φ Hi Ω

liquid may flow out between the edges of the slot and the flexible element .

Referring now to Figs 5 and 6, two embodiments of a deaeration and throttling device combined with a layering pipe according to the invention are shown. The device comprises a spool -shaped body 17, which is contained in a pipe portion 18. The spool-shaped body presents a first tapering portion 19 directed upwards, and a second tapering portion 20 directed downwards, and between these portions the spool-shaped body has its largest cross- sectional dimension in a middle portion 21. A constriction or flow-restricting passage 22 is defined between said middle portion and the inner wall of the pipe portion 18 in such manner that an upper chamber 23 is de- fined in the pipe portion 18 above the middle portion 21 and a lower chamber 24 therebelow.

The spool -shaped body is intended to be contained in a pipe portion at the top of an accumulator tank, for instance at the top of the layering pipe 6 of Fig. 1. More specifically, in such manner that the lower tapering portion 20 is at least partly submerged below an open liquid surface 25 in the accumulator tank, while the upper tapering portion 19 protrudes with its tapering end to the mouth of the inlet pipe 5, the diameter of which is smaller than that of the pipe portion 18. As liquid flows into the accumulator tank via the inlet pipe 5, the liquid will be distributed in the form of a gradually thinning liquid layer on the envelope surface of the upper tapering portion of the spool -shaped body. The flow-restricting passage 22 between the inner wall of the pipe portion and the middle portion 21 of the spool-shaped body decelerates the flow of the liquid so that an open liquid surface 26 is formed also in the upper chamber 23. Once the liquid has passed the passage 22, it will follow the envelope surface of the lower tapering portion in the form of a thin liquid layer and will make contact with the liquid surface 25 of the accumulator tank at an advantageously low velocity without causing unnecessary mixing of the liquid in the accumulator tank.

Owing to the fact that the liquid flows around the spool-shaped body in a thin liquid layer, the release of any gas dissolved in the liquid, especially air, is facilitated since the gas accumulates on the surface of the spool-shaped body in the form of gas bubbles which gradually grows in size and finally rises. For this reason, the device comprises a pressure-equalizing passage 27 which connects the upper chamber 23 with the ambient atmosphere and through which released gas can escape. The pressure-equalizing passage is formed in an insert piece 28 which is inserted into the upper part of the pipe portion 18 and which has a conical inner bore tapering upwards so that the upper chamber 23 in its upper part has a cross-sectional dimension which is essentially equivalent to the inner cross-sectional dimension of the inlet pipe, and which increases gradu- ally downwards so that, on a level with the middle portion, the cross-sectional dimension is the same as that of the pipe portion 18.

The difference between the embodiments of the deaeration and throttling device shown in Figs 5 and 6, respectively, is that the spool -shaped body 17 of Fig. 5 presents conical, upper and lower tapering portions, while the upper tapering portion 19 of the spool -shaped body of Fig. 6 is convex and the lower tapering portion 20 is concave. Many other shapes of the spool-shaped body are conceivable within the scope of the claims.

The deaeration and throttling device is shown and described herein specifically in combination with a layering pipe and in a draining heating system where water is the preferred heating medium. It will be appreciated, however, that it could be used in every situation where it is desirable to remove a gas from any arbitrary liquid and/or reduce the velocity of flow of said liquid.

Claims

1. A layering pipe for distribution and storing of an incoming liquid with an arbitrary temperature in a storage tank (3) intended for said liquid, in which the stored liquid is layered at different temperature levels due to differing densities, the layering pipe (7) being adapted to extend vertically through the liquid stored in the tank and comprising an inlet end and an outlet opening provided with a check-valve device which allows an outflow of liquid into the tank but prevents an inflow from the tank into the layering pipe, c h a r a c t e r i s e d in that the outflow opening is in the shape of an elongate opening or slot (8) extending in the longitudinal direction of the layering pipe (7) and along essentially the whole length of said layering pipe, and that the check valve device comprises an elongate, flexible element (11) , which is fixed relative to the layering pipe along a line or an area parallel to the longitudinal extension of the outflow opening and which, by itself or together with other flexible elements, overlaps the opening from the outside of the layering pipe in such manner that it allows an outflow of liquid into the tank by the flexible element being deformed locally and separated from the layering pipe in the area of a liquid layer in the tank having the same temperature as the liquid in the layering pipe, while preventing flow in the opposite direction.

2. A layering pipe according to claim 1, c ha r a c t e r i s e d in that it comprises one or more continuous slots (8) extending substantially along the whole length of the layering pipe.

3. A layering pipe according to claim 1 or 2 , c h a r a c t e r i s e d in that it comprises an angle element (9) which is located at a distance outside the slot (8) and provided with holes (10) .

4. A layering pipe according to claim 3 , c h a r a c t e r i s e d in that the total hole area of the angle element (9) is at least equivalent to the opening area of the slot (8) .

5. A layering pipe according to any one of the preceding claims, c h a r a c t e r i s e d in that the check valve device comprises two flexible elements (11) which are fixed relative to the layering pipe (7) on each side of the slot (8) .

6. A layering pipe according to claim 5, c h a r a c t e r i s e d in that the two flexible elements (11) abut against each other along their respective longitudinal edges.

7. A layering pipe according to any one of the pre- ceding claims, c h a r a c t e r i s e d in that it comprises a deaeration and throttling device which is contained in an upper pipe portion (18) of the layering pipe and which comprises a spool-shaped body (20) which is tapering in cross section towards the end regions, with the greatest cross-sectional dimension in a middle portion (21) in such manner that a flow-restricting passage (22) is formed between the inside of the pipe portion and the middle portion of the spool-shaped body.

8. A layering pipe according to claim 7, c h a r - a c t e r i s e d in that the spool-shaped body (20) has the shape of two cones whose bases are turned to face each other.

9. A layering pipe according to claim 7 or 8, c h a r a c t e r i s e d in that two chambers are de- fined in the deaeration and throttling device, viz. an upper chamber (23) above the middle portion (21) of the spool -shaped body and a lower chamber (24) below the middle portion, the upper chamber (23) communicating with the ambient atmosphere by the intermediary of a pressure- equalizing passage (27) .