IT202000022078A1 - THERMAL ACCUMULATOR - Google Patents

Description

DESCRIPTION

Attached to a patent application for INDUSTRIAL INVENTION having the title

?THERMAL ACCUMULATOR?

The present invention relates to the industrial sector and in particular to the thermal plant sector.

Specifically, the present invention relates to a heat accumulator which is used in winter air conditioning as well as in the production of hot water for hygienic and sanitary uses in civil and industrial buildings.

In this sector, it is particularly important to guarantee high energy efficiency systems in order to obtain energy savings and a reduction in operating costs as well as less use of traditional energy sources to the benefit of the environment.

How ? known, thermal accumulators are used in combination with at least one of thermal generators, heat pumps, gas boilers and thermal solar systems with the aim of accumulating thermal energy for periods of time on the order of twenty-four hours by storing a heat transfer fluid, typically water, where this thermal energy is used immediately or within twenty-four hours for the production of domestic hot water or for winter air conditioning.

By means of these thermal accumulators, the principle of thermal stratification is exploited in order to have very hot and very cold water available in the same tank. Greater ? the thermal stratification, the better it will be? the efficiency of the energy thermal accumulator.

Structurally, these thermal accumulators have a substantially cylindrical containment body which defines an internal volume typically with a single room, ie one not divided into further compartments.

In a bottom portion of the thermal accumulator? operationally arranged is a heat exchanger, operationally connected to heat generators (typically of the renewable source type, such as for example solar thermal systems) which are configured to introduce heat into the thermal accumulator.

Also, in the upper portion of the thermal accumulator ? a further heat exchanger is arranged, operatively connected to the water mains and configured to withdraw heat from the thermal accumulator with the aim of producing domestic hot water.

By means of this apparatus for introducing and withdrawing heat, a continuous cyclic movement of the heat transfer fluid is generated inside the thermal accumulator.

In fact, the thermal fluid at temperature pi? low naturally converges towards the bottom of the containment body due to the high density? where, upon coming into contact with the heat exchanger arranged on the bottom of the containment body, it heats up and converges again towards the upper portion of the thermal accumulator.

Also, the heated heat transfer fluid converges towards the upper part of the thermal accumulator where, coming into contact with the heat exchanger arranged above, it cools down and, once the density has increased, it converges again towards the bottom of the thermal accumulator.

Although these thermal accumulators are widely used, they have some important drawbacks which make their use poorly performing.

First of all, due to the constant movement of the heat transfer fluid, isn't it? possible to achieve a thermal stratification such as to ensure high efficiency of the energy system as a whole. In fact, the temperature of the heat transfer fluid on the bottom of the thermal accumulator will not result? low enough to allow the heat generator, connected to the respective heat exchanger, to work at high efficiency, so as the temperature of the heat transfer fluid in the upper portion of the thermal accumulator will not result? high enough to allow a high production of domestic hot water.

The thermal accumulators of the known typology also provide for a plurality of of accessory inputs, which can be combined with respective additional systems, such as, for example, winter heating systems, and additional heat generators, such as, for example, gas boilers or heat pumps, configured for the introduction of heat into the thermal accumulator .

The heat of the efficiency of the renewable source heat generator will mean? an increase in the use of heat generators with traditional sources, with an increase in operating costs and an exploitation of non-renewable energy resources.

Furthermore, the use of these inlets, obtained on the side walls of the containment body, contributes to a further mixing of the heat transfer fluid inside the heat accumulator with a consequent further drop in the performance of the heat accumulator.

In the light of the above, the technical task of the present invention? that of proposing a thermal accumulator which overcomes at least some of the drawbacks of the prior art mentioned above.

Particularly, ? object of the present invention is to provide a thermal accumulator capable of achieving a high thermal stratification of the heat transfer fluid.

Another purpose of the present invention ? make available a thermal accumulator capable of being extremely performing. Another purpose of the present invention ? provide a thermal accumulator capable of, once installed, occupying a limited portion of space.

The technical task specified and the aims specified are substantially achieved by a thermal accumulator which comprises a containment body, a lower chamber, an upper chamber, at least one ascent duct and at least one descent duct.

The containment body defines a containment volume having a substantially parallelepiped shape suitable for storing a heat transfer fluid. The lower chamber defines a lower heat exchange volume suitable for heating the heat transfer fluid and includes a lower heat exchanger operating by means of an auxiliary heat transfer fluid while the upper chamber defines a higher heat exchange volume suitable for cooling the heat transfer fluid and includes an exchanger of superior heat operating through sanitary water.

L?At least one duct of ascent ? arranged in flow communication with the lower chamber and the upper chamber and ? configured to transport the heated heat transfer fluid from the lower heat exchanger to the upper heat exchanger by convection.

L?at least one duct of descent ? arranged in flow communication with the lower chamber and the upper chamber and ? configured to transport the cooled heat transfer fluid from the upper heat exchanger to the lower heat exchanger by convection.

Further characteristics of the present invention will appear more clearly from the indicative and therefore non-limiting description of a preferred but not exclusive embodiment of a thermal accumulator.

This description will set forth below with reference to the attached drawings, provided for indicative and therefore non-limiting purposes only, in which: - figure 1 shows a front schematic view of a possible embodiment of a thermal accumulator in accordance with the present description;

- figure 2 shows a lateral schematization of the thermal accumulator of figure 1;

- figure 3 schematically shows a detail of the thermal accumulator of figure 1.

With reference to the figures, with the reference number 1 ? a thermal accumulator in accordance with the present invention has been indicated as a whole.

The thermal accumulator 1 comprises a containment body 2, a lower chamber 3, an upper chamber 4, at least one ascent duct 5 and at least one descent duct 6.

The containment body 2 defines a containment volume ?V? substantially parallelepiped in shape, suitable for storing a heat transfer fluid.

Preferably but not limitedly, this heat transfer fluid is water. Advantageously, by means of this conformation, the thermal accumulator 1 can? be installed where the available spaces are limited. According to a preferred embodiment, the containment body 2 is made of carbon steel.

Furthermore, the containment body 2 can? have an external coating in painted sheet metal.

The insulation? preferably made of EPDM elastomer. However, in alternative embodiments, further materials capable of performing the same function are not excluded.

The containment volume ?V? appears to be divided into a plurality? of portions, including the lower chamber 3, the upper chamber 4 and the ascent and descent ducts 5, 6.

The lower chamber 3 ? formed in a bottom portion of the containment body 2.

In particular, the lower chamber 3 defines a lower heat exchange volume ?V1? suitable for heating the heat transfer fluid and comprises a lower heat exchanger 7 operating by means of an auxiliary heat transfer fluid.

Said lower heat exchanger 7, in use, is coupled to a respective heat generation plant, not shown in the attached figures, which is configured to supply heat to the heat accumulator 1 via the lower heat exchanger 7 itself.

This heat generation plant can be of any type. Preferably, this lower heat exchanger is coupled to a system of the renewable source type, such as for example a solar thermal system.

In other words, the lower heat exchanger 7 receives the auxiliary heat transfer fluid from the heat generation system at a temperature such as to heat the heat transfer fluid which flows into the bottom portion of the containment body 2, and in particular into the lower chamber 3 , thus introducing heat into the thermal accumulator 1.

The upper chamber 4 is obtained in an upper portion of the containment body 2.

In particular, the upper chamber 2 defines a higher heat exchange volume ?V2? suitable for cooling the heat transfer fluid and comprises an upper heat exchanger 8 operating with sanitary water.

This upper heat exchanger 8 is typically combined with a water mains.

In other words, the upper heat exchanger 8 ? configured in such a way as to heat the sanitary water entering the upper heat exchanger 8 by means of the heat drawn from the heat transfer fluid which flows into the upper portion of the containment body, and in particular into the upper chamber 4, extracting heat from the thermal accumulator 1 .

According to a preferred embodiment, illustrated by way of example in the attached figures, at least one, preferably both, of the lower heat exchanger 7 and the upper heat exchanger 8 has a serpentine shape which defines a cylindrical spiral having an axis of development longitudinal lying on a respective horizontal plane.

even more in particular, at least one, preferably both, of the lower heat exchanger 7 and the upper heat exchanger 8 can present a finned surface in order to increase the heat exchange.

Furthermore, at least one, preferably both, of the lower heat exchanger 7 and the upper heat exchanger 8 can be made of a high conductivity material? thermal, such as copper.

According to a peculiar structural feature of the present invention, the lower chamber 3 and the upper chamber 4 are put into flow communication by the at least one ascent duct 5 and by the at least one descent duct 6.

In particular, the at least one ascent duct 5 ? configured to transport the heated heat transfer fluid from the lower heat exchanger 7 to the upper heat exchanger 8 by convection. Also, the at least one descent duct 5 ? configured to transport the cooled heat transfer fluid from the upper heat exchanger 8 to the lower heat exchanger 7 by convection.

In other words, this at least one ascent duct 5 and this at least one descent duct 6 are made and arranged so as to define a connection between the upper chamber 4 and the lower chamber 3, defining a flow communication between the upper chamber 4 and the chamber lower 3. Functionally, the heat transfer fluid, cooled by the upper heat exchanger 8, increases its density? and is conveyed by at least one descent duct 6 towards the lower heat exchanger 7, taking advantage of the higher density? of the cooled heat transfer fluid.

In a similar way, the heat transfer fluid heated by the lower heat exchanger 7 expands and is conveyed by at least one rise duct 5 towards the upper heat exchanger 8.

In this way, a cyclic movement of the heat transfer fluid is created which substantially concerns the lower 3 and upper 4 chambers and the ascent and descent ducts 5, 6, which interferes in a limited way with the heat transfer fluid stored in the remaining portions of the body containment 2.

In this way, advantageously, the movement of the heat transfer fluid is limited and the thermal stratification in the containment volume ?V? is improved. to the advantage of the efficiency of the thermal accumulator 1 and of the systems combined with it.

According to a further aspect of the present invention, the at least one ascent duct 5 and the at least one descent duct 6 can be coaxial with each other. Preferably the at least one ascent duct 5 ? at least partially arranged inside the at least one descent duct 6.

As can be clearly seen from the attached figures, which illustrate a preferred embodiment of the thermal accumulator 1 for exemplifying and therefore non-limiting purposes, ? there is a single ascent duct 5 at least partially arranged inside a respective descent duct 6.

In order to limit the heat exchange between the heated heat transfer fluid, passing through the ascent duct 5, and the cooled heat transfer fluid, passing through the descent duct 6, at least one of the ascent and descent ducts 5, 6, preferably both are insulated.

In this way, by limiting the passage of heat from the heated heat transfer fluid to the cooled heat transfer fluid, the energy efficiency of the thermal accumulator 1 and of the systems combined with it is increased. According to a further aspect of the invention, the lower chamber 3 can comprise lower separating walls 9 shaped so as to convey the cooled heat transfer fluid towards the lower heat exchanger 7 defining a lower convective path ?L1? in which the cooled heat transfer fluid is substantially separated from the heated heat transfer fluid.

Also, by defining a lower convective path ?L1?, the lower separation walls 9 can be shaped so as to convey the heated heat transfer fluid towards the at least one ascent duct 5 in which the heated heat transfer fluid is substantially separated from the heat transfer fluid cold.

The upper chamber 4 can? comprise upper separation walls 10 shaped so as to receive the cooled heat transfer fluid from the upper heat exchanger 8 and convey it into the at least one descent duct 6 along an upper convective path ?L2?.

Advantageously, in this way, mixing between the heated heat transfer fluid and the cooled heat transfer fluid is limited.

In other words, the lower convective path ?L1? ? defined in such a way as to be linear, or in such a way that the cooled heat transfer fluid, descending near? of the lower chamber 3, and therefore in the vicinity? of the lower heat exchanger 7, receives heat substantially from the lower heat exchanger 7 and not from the heated heat transfer fluid.

Similarly, the upper convective path ?L2? ? defined in such a way as to be linear, or in such a way that the heated heat transfer fluid, rising in the vicinity? of the upper chamber 4, and therefore in the vicinity? of the upper heat exchanger 8, essentially releases heat to the upper heat exchanger 8 and not to the cooled heat transfer fluid.

Preferably, the lower separating walls 9 separate the cooled and descending heat transfer fluid from the heated and rising heat transfer fluid so that the descending heat transfer fluid reaches the lower heat exchanger 7 from below while the heated heat transfer fluid leaves the lower chamber 3, and then the lower heat exchanger 7, being conveyed from above into the ascent duct 5.

Structurally, according to the preferred embodiment, the lower separating walls 9 are integral with or connected to the ascent duct 5, defining in a lower portion of the ascent duct 5 a converging portion for conveying the heat transfer fluid.

In a similar way, the upper separation walls 10 collect and convey the cooled heat transfer fluid towards the descent duct 6.

Structurally, according to the preferred embodiment, the upper separation walls 10 are integral with or connected to the descent duct 6, defining in an upper portion of the descent duct 6, a converging portion for conveying the heat transfer fluid.

According to a further aspect of the invention, the thermal accumulator 1 can understand one or more by-pass chambers 11.

Each by-pass chamber 11 comprises inlet holes 11a and/or delivery holes 11b, obtained on a portion of the lateral wall of the containment body 2 and arranged for coupling to respective auxiliary systems.

For example, these inlet holes 11a and/or delivery holes 11b can be combined with heat generators, such as boilers, and with winter heating systems.

Preferably, such one or more? by-pass chambers 11 are operatively arranged according to a respective operating temperature of the auxiliary system at which one or more? by-pass chambers 11 are obtained.

In other words, such one or more? by-pass chambers 11 are operatively arranged according to a determined thermal stratification reached in steady state operation of the thermal accumulator 1.

Furthermore, such one or more? by-pass chambers comprise ports 11c obtained on internal walls 12 of the respective by-pass chamber 11 configured for an exchange of the heat transfer fluid the respective by-pass chamber 11 and the containment volume ?V?.

Advantageously, the internal walls 12 of the by-pass chamber 11 brake the heat transfer fluid entering an inlet hole 11a, maintaining an adequate thermal stratification inside the containment volume ?V?.

The preferred embodiment of the thermal accumulator 1, illustrated by way of non-limiting example in the attached figures, has a by-pass chamber 11 comprising an inlet hole 11a, which can be combined, in use, with a heat generation plant ( and in particular a gas boiler), and a delivery hole 11b, which can be combined in use with a winter heating system.

Furthermore, further inlet holes 11d and/or delivery holes 11e obtained near the of one of these by-pass chambers 11 and combined with the same systems to which ? associated with the respective bypass chamber 11.

The by-pass chamber 11 exploits the heat accumulated in the thermal accumulator 1, which essentially acts as a thermal flywheel. In particular, if the thermal request of the heating system is greater than the heat supplied by the boiler, then the heat transfer fluid stored inside the thermal accumulator 1 releases part of the stored heat. On the contrary, if the request from the heating system is lower than that supplied by the heat generation system, in that case the heat generator will yield? part of the heat to the thermal accumulator 1.

According to a further aspect of the present invention, the thermal accumulator 1 can includes one or more clearing houses 13.

Such one or more? compensation chambers 13 comprise inlet holes 13a and/or delivery holes 13b, obtained on a portion of the side wall of the containment body 2 delimiting the respective compensation chamber 13 and arranged to be coupled to respective ducts of one or more? heat pumps, and a respective auxiliary ascent duct 13c capable of making the at least one compensation chamber 13 communicate with the upper chamber 4 and configured to convey heated heat transfer fluid from the compensation chamber 13 to the upper chamber 4 by means of convection

Advantageously, by exploiting the transport by convection, the heat transfer fluid heated by the heat pump is transferred near the of the upper heat exchanger 8 by means of the respective auxiliary ascent duct 13c with the aim of transferring heat to the sanitary water.

Preferably, as shown in figure 1, the thermal accumulator 1 comprises two compensation chambers 13.

According to a further aspect of the invention, the thermal accumulator 1 can understand a plurality of stratification elements 14 configured to limit movement of the heat transfer fluid in the containment volume 2.

In particular, the stratification elements 14 can have a substantially planar and/or concave shape and can be spaced apart along a height of the containment body 2.

Preferably, as illustrated in the attached figures, the stratification elements 14 are arranged substantially horizontally, in order to especially limit vertical movement of the fluid.

Advantageously, in other words, these stratification elements 14, by limiting the movement of the heat transfer fluid inside the containment volume ?V?, help to increase the stratification and therefore the efficiency of the thermal accumulator 1 and of the systems connected to it .

Furthermore, the stratification elements 14 are preferably grouped in one or more? columns operatively arranged in the containment volume 2.

The preferred embodiment, illustrated by way of example in the attached figures, provides for these stratification elements 14 to be connected to the auxiliary ascent ducts 13c and to the descent duct 6.

Advantageously, the present invention overcomes the drawbacks of the prior art allowing to ensure a high thermal stratification of the heat transfer fluid and to be extremely performing.

Such a result? achieved by subdividing the containment volume 2 into the upper 4 and lower 3 chambers and into the ascent 5 and descent 6 ducts which locate the fluid dynamic exchange substantially within them.

Such a result? also achieved through the internal walls 12 of the by-pass chambers 11 which limit the mixing of the heat transfer fluid entering from the respective inlets 11a.

Such a result? also achieved thanks to the present of a plurality? of stratification elements 14 which limit the movement of the heat transfer fluid inside the containment volume ?V?.

Advantageously, moreover, the present invention provides a thermal accumulator 1 which is able to have a smaller overall size as well as? to occupy a limited amount of space.

In fact, for the same domestic hot water produced, the high efficiency of the heat accumulator 1 allows it to have smaller dimensions than known heat accumulators.

Furthermore, the substantially parallelepiped shape of the thermal accumulator 1 allows installation where known thermal accumulators, typically cylindrical in shape, cannot be installed.

Claims (9)

1. Heat accumulator (1) for winter conditioning and for the production of domestic hot water, comprising: - a containment body (2) defining a containment volume (V) of substantially parallelepiped shape suitable for storing a heat transfer fluid: - a lower chamber (3) defining a lower heat exchange volume (V1) suitable for heating said heat transfer fluid and comprising a lower heat exchanger (7) operating by means of an auxiliary heat transfer fluid; - an upper chamber (4) defining an upper heat exchange volume (V2) suitable for cooling said heat transfer fluid and an upper heat exchanger (8) operating with sanitary water; - at least one rise duct (5) arranged in flow communication with said lower chamber (3) and said upper chamber (4) and configured to transport said heated heat transfer fluid from said lower heat exchanger (7) to said exchanger by convection top heat (8); And - at least one descent duct (6) arranged in flow communication with said lower chamber (3) and said upper chamber (4) and configured to convey by convection said cooled heat transfer fluid from said upper heat exchanger (7) to said exchanger bottom heat (8). 2. Thermal accumulator (1) according to claim 1, wherein said at least one ascent duct (5) and said at least one descent duct (6) are coaxial with each other; preferably said at least one ascent duct (5) being at least partially arranged inside said at least one descent duct (6). 3. Thermal accumulator (1) according to one of the preceding claims 1 or 2, wherein said lower chamber (3) comprises lower separating walls (10) shaped so as to convey said cooled heat transfer fluid towards said lower heat exchanger (7) defining a lower convective path (L1) in which said cooled heat transfer fluid is substantially separated from said heated heat transfer fluid. 4. Heat accumulator (1) according to any one of the preceding claims, wherein said upper chamber (4) comprises upper separating walls (11) shaped so as to receive said cooled heat transfer fluid from the upper heat exchanger (8) and convey it into said at least one descent duct (6). 5. Heat accumulator (1) according to any one of the preceding claims, wherein at least one, preferably both, of said lower heat exchanger (7) and said upper heat exchanger (8) has a serpentine shape defining a cylindrical spiral having an axis of longitudinal development lying on a respective horizontal plane. 6. Thermal accumulator (1) according to any one of the preceding claims, comprising one or more? by-pass chambers (11) comprising inlets (11a) and/or outlets (11b), obtained on a portion of the side wall of the containment body (2) and arranged for coupling to respective auxiliary systems, and ports (11c) formed on the internal walls (12) of the respective by-pass chamber (11) configured for an exchange of said heat transfer fluid between said by-pass chamber (11) and said containment volume (V). 7. Thermal accumulator (1) according to any one of the preceding claims, comprising one or more? compensation chambers (13) having inlets (13a) and/or outlets (13b), obtained on a portion of the side wall of said containment body (2) delimiting said compensation chamber (13) and arranged to be coupled to respective ducts of one or more heat pumps, and a respective auxiliary ascent duct (13c) able to make said at least one compensation chamber (13) communicate with said upper chamber (4) and configured to convey heated thermal fluid from said compensation chamber (13) to said upper chamber (4) by convection. 8. Thermal accumulator (1) according to any one of the preceding claims, comprising a plurality of stratification elements (14) configured to limit movement of said heat transfer fluid in said containment volume (V); said layering elements (14) having a substantially planar and/or concave shape and being spaced apart along a height of said containment body (2). 9. Thermal accumulator (1) according to claim 8, wherein said plurality? of layering elements (14) are grouped in one or more? columns operatively arranged in said containment volume (2).