EP4194767A1

EP4194767A1 - Instantaneous interaccumulator for fluids for human consumption and/or fluid foodstuffs

Info

Publication number: EP4194767A1
Application number: EP21853172.1A
Authority: EP
Inventors: José Raúl MARTÍNEZ VÁZQUEZ
Original assignee: Hydronik Soluciones Tecnicas Sl
Current assignee: Hydronik Soluciones Tecnicas Sl
Priority date: 2020-08-07
Filing date: 2021-07-28
Publication date: 2023-06-14
Also published as: WO2022029353A1; ES2894175A1

Abstract

The present invention discloses a new type of instant water interaccumulator for sanitary or industrial consumption that incorporates an inlet (A) for the fluid to be heated/ cooled at the top of the structure and an outlet (B) for the hot/ cold fluid arranged on a side of the bottom of the structure. Additionally, it comprises an inlet distributor (1) for the fluid to be heated/ cooled and an outlet distributor (2) for the hot/ cold fluid; a purge outlet (3) arranged at the bottom of the structure; a probe outlet (4) arranged at the top of the structure; a plurality of primary fluid inlet and outlet ports (5), arranged on one of the sides of the structure of said interaccumulator; an interaccumulator casing (6) made of any material that supports the physical and chemical characteristics of the primary fluid and is used for both heating and cooling the secondary fluid, and supports the internal and external components; a thermal protector (7) that allows thermal insulation; at least one inner coil (8a); and at least two outer coils (8b), where said coils (8a) and (8b) are corrugated and have the same length.

Description

OBJECT OF THE INVENTION

The present invention discloses an instantaneous fluid interaccumulator that allows instant heating of large amounts of water for human consumption and/or food fluids. It comprises a set of corrugated steel coils of the same length combined with a distributor that allows the interaccumulator to have only one water inlet and one water outlet.

BACKGROUND OF THE INVENTION

Water heaters are widely used in industry and homes, and the storage capacity of their tanks is related to the intended use of the water. The most commonly used hot water tanks serve a single residence. The capacity of domestic tanks in America varies from 75 to 450 liters (20 to 120 gallons), in Israel, their typical capacity is 120 to 200 liters. Smaller electrically heated tanks serve only one area of the residence, such as the kitchen, and are manufactured in sizes as small as 30 liters.
All hot water storage tanks are insulated to retain heat from the moment of application until hot water is required. Current insulation methods are unsatisfactory when heat preservation is required overnight, for example, when solar-heated water is required for a morning shower. Hot water tanks that are exposed to the elements during the winter months tend to lose heat for even shorter periods. This problem can be alleviated by using thick insulation; however, the use of high-quality thick insulation is expensive and also increases the cost of the tank's outer cover of steel; it can also cause difficulties when the tank must be moved or installed in a restricted space.
There are two common types of electric water heaters for domestic sanitary use: accumulators and instantaneous water heaters. Both types are used because each has certain advantages and disadvantages.
Instantaneous hot water production is done at the same time, i.e., the water is heated at the same time as it is consumed. In contrast, in storage systems, water is heated slowly and maintained at a consumption temperature inside a tank.
The advantage of accumulator water heaters is the fact that they can distribute large amounts of water at a pre-set temperature, well above what is normally required from faucets in sinks or showers, and therefore can also meet the needs of multiple users while using relatively low energy consumption; in Italy, this is generally 1200W for the most common models. However, the disadvantage is that these models require many hours to complete the supply of hot water once it has been used, and although the tanks are insulated, they also suffer from strong heat dispersion. In addition, users of sanitary hot water systems have almost no way of knowing how much hot water, if any, is available for their use. The hot water storage tank is usually completely closed, covered with thermal insulation material, and often installed in a difficult-to-reach location. The common practice is to open a hot water faucet, drain all the water contained in the pipe coming out of the tank, and manually test the water temperature.
The US patent US3666918 discloses a water heating system that includes a tank for storing heated water for extraction to a point of use and having a cold water inlet to replenish the extracted water; a conduit having an immersion heater, the conduit having a water intake manifold for supplying water from the tank to pass in heat exchange relationship with the immersion heater and having a heated water outlet disposed in flow communication with the point of use, the manifold having openings disposed in flow communication with different levels within the tank at which different water temperatures may exist, whereby the water temperature passing in heat exchange relationship with the heater is an integral part of the water temperatures of the different levels; and a temperature sensor for controlling the rate of heat input to the water passing through the conduit in response to integral temperature.
In traditional boilers, the heat output largely depends on the amount of water flowing through the tube bundle or coil. Therefore, one way to increase this heat output is by modifying the dimensions of each turn of the tube bundle measured orthogonally with respect to its longitudinal axis. In other words, in this way, coils with different external diameters are used while the internal diameter remains the same. This increases the heat exchange surface area of the coil (through which water flows) and, consequently, the heat output of the boiler.
However, with this known operating mode, boilers with coils of different diameters have different geometric characteristics or different external diameters depending on the heat output generated by them. For these reasons, boiler manufacturers must produce end closure bodies and components with different sizes (diameters), which implies high production costs and significant storage costs.
International patent application WO2015/140713 describes a method for manufacturing a set of heat exchange cells with a thermal power within a predetermined range of maximum and minimum values. Each heat exchange cell comprises at least one heat exchanger mounted in a containment casing. The method comprises the steps of: a) providing an individual containment casing for a plurality of heat exchange cells, the casing has a constant extension while the thermal power of the cell varies within the range of thermal power values and is equal to the axial extension of the cell having the minimum thermal power within the range of thermal power values; b) providing a plurality of helically shaped heat exchangers with an individual thermal power within said range of maximum and minimum values, each comprising at least one tubular conduit for the circulation of a first heat transfer fluid wound around a longitudinal axis of the helix according to a plurality of coils; c) mounting at least one helix-shaped heat exchanger from the plurality of heat exchangers of the set within said individual containment casing. The plurality of heat exchangers in the set has an internal diameter that is substantially constant while the heat output of the heat exchanger varies within a range of thermal power values; the tubular conduit of the heat exchanger has a radial extension of the coils proportional to the thermal power of the heat exchanger and thus maintains the axial extension of the heat exchanger substantially constant while the thermal power varies and is equal to the axial extension of the heat exchanger having the minimum thermal power within the range of thermal power values of the set.
The patent application WO2012/156954 relates to a heat exchanger that comprises a heat exchanging unit comprising substantially one or more coaxial coiled tubes and a casing for containing the heat exchanging unit. The casing has a first bottom wall, a second bottom wall and a peripheral part between the two bottom walls. Each tube has a first end and a second end. The heat exchanging unit is supported by the first bottom wall of the casing, with the first end and the second end of each tube being substantially located in the first bottom wall of the casing.
The great advantage of instantaneous water heaters is that they can supply an unlimited amount of hot water with virtually no heat dispersion, but they use a very high energy consumption to meet each individual use every time.
The only difference between a water inter-accumulator and an accumulator is the coil located inside the former. Both always need to be connected to an external heat source, generally a boiler, but also, for example, a solar panel or a wood stove, the primary hot water, produced by the external heat source, heats the sanitary water that is inside the same tank. The coil is the exchanger that transfers the heat from the primary circuit to the secondary circuit (ACS). As mentioned, the present invention discloses a water inter-accumulator that allows the instant heating of large amounts of water and/or food fluids in a novel way that turns heating into an instantaneous fact, reduces installation, operational and maintenance costs, increases system efficiency, and eliminates problems from Legionella and similar bacteria that exist in traditional facilities.

DESCRIPTION OF THE DRAWINGS

In order to complement the description being made and to help better understand the characteristics of the invention, according to a preferred example of its practical embodiment, a set of drawings is attached as an integral part of said description, where the following has been illustrated with an illustrative and non-limiting character:

Figure 1 shows a top view of the water inter-accumulator of the invention, where the arrangement of the coils (8a) and (8b) and the inlet distributor (1) are shown.
Figure 2 shows a view of the components of the water inter-accumulator of the invention, showing the internal arrangement of the coils (8a) and (8b) and the rest of the components.
Figure 3 shows a top view of the water inter-accumulator of the invention, where the arrangement of the coils (8a) and (8b) and the inlet distributor (2) are shown.

DESCRIPTION OF THE INVENTION

The ACS (Sanitary Hot Water) systems are those that distribute consumption water subjected to some heating treatment. These installations have a certain energy importance and are susceptible to contaminations by bacteria that find in their interior a warm and humid medium that facilitates their proliferation. Therefore, they are installations obliged to comply with specific regulations dictated by the different countries.
At present, apart from traditional accumulators, there are inter-accumulators of different types, in all cases the envelope encloses the water or fluid (ACS). This is heated by another primary fluid that passes through the coils. In these cases, the exchange capacity is limited, since these systems try to maximize the amount of accumulated water (they take a long time to heat the water), and they do not eliminate the possibility of generating bacterial colonies inside.
There are also semi-instantaneous production inter-accumulators, where heat passes from the equipment that produces it to the tank through the lower coil, heating the water in the tank, which in turn semi-instantaneously heats the ACS water that passes through the 2nd inner coil. For small consumptions (domestic systems), they work well, allowing for about 4-5 consecutive showers before losing temperature.
The present invention reveals a novel instant production inter-accumulator for large quantities of fluid, composed from the outside to the inside by the following elements: an outer lining that allows protecting the insulating element and is manufactured in various materials depending on the final location of the inter-accumulator; a thermal insulator that can be composed of different materials and thicknesses, depending on the necessary energy efficiency; an envelope that provides structural resistance to the whole assembly and is responsible for containing the primary fluid that will heat the ACS. In this envelope, there are hydraulic connections, holes for external probes, and a drain outlet. For its manufacture, carbon steel or stainless steel is recommended; distributors whose function is to prevent consumption water ACS from coming into contact with any other element or fluid other than the external pipes, provide cold water to the inter-accumulator, or extract it once heated.
These distributors are made of stainless steel and all connections with the inner coils are also made of stainless steel. The coils are made of corrugated stainless steel, which are responsible for transferring the heat generated by the boiler and contained within the casing to the food fluid that passes through them.
The interaccumulator of the invention allows for real instantaneous production capable of heating enormous amounts of water with a significant thermal jump. Currently, there are no elements in the state of the art that equal or improve the relationship/size of liters heated per minute.
The stainless steel distributors at the inlet and outlet of the DHW of the interaccumulator ensure that the DHW does not come into contact with any element other than the stainless steel (AISI316) with which all internal elements are made. The fact that the drinking water does not touch the steel of the casing means that it is not necessary to install any type of sacrificial anode or electronic anode to prevent corrosion of the casing. This is a significant economic saving in external elements that are not necessary to install or maintain.
The position and location of the distributor allows for a direct connection from the external conduits to the Interaccumulator with the interior, a firm connection where the external conduits can be screwed. The casing can be made of any material that can withstand the temperatures and qualities of the primary fluid, since its only functionality is to contain the primary fluid, allow the connections of the pipes and probes. The DHW is never static inside the coils, which means that with an adequate temperature, it is impossible for Legionella to be generated inside the tanks.
The coils are very insensitive to calcification and encrustation due to their corrugated structure, since the turbulence generated inside the coils due to the water flow makes it more difficult for lime, biological or any other type of incrustation to form, since the same turbulence generates an erosive effect that prevents them. In case the water does not flow fast enough to generate that erosive effect, another effect is produced due to the temperature changes inside the interaccumulator. These temperature changes cause the coil to expand and contract (amplified by the corrugated format of the coil). These repeated expansions and contractions significantly delay the appearance and development of any type of incrustation, whether it be lime, bacterial or any other type.
As the coils are corrugated and flexible, they are able to withstand increases in pressure in the system without being damaged, making the installation more durable, even in case of expansion vessel failures, water hammer or similar malfunctions in the installation.
The fact that there is only one inlet and one outlet for domestic hot water greatly facilitates the assembly of the interaccumulator, avoiding errors and mistakes in its installation.
The insulation used can be rigid or flexible and of various thicknesses, allowing the equipment to adapt to different locations (indoors or outdoors, cold or warm environments, wider or narrower passage widths).
Having both the heat exchange element (coils) and the thermal inertia element (envelope) in the same volume eliminates many of the elements of the traditional system, also eliminating its installation, maintenance and cleaning costs. This means that there is no need to incorporate external heat exchangers or ACS recirculation elements between accumulators.
The pressure drops in the system never exceed those of traditional systems and their plate exchangers. Only during critical consumption moments do we equal these pressure drops, with the rest of the time being 99.99% of the time a system with lower pressure drops than traditional ones, and therefore more energy efficient.
Regarding the energy efficiency of the envelope and assuming a thermal protection at least similar to that of any traditional system, lower heat dissipation losses are achieved compared to any traditional system. The dissipation surface (envelope surface) is much smaller (800L) than that of traditional ones (2,000L), making thermal losses much lower than any other traditional accumulation system. The energy efficiency in the heat exchange phase from the primary fluid to the domestic hot water is higher than traditional systems with plate exchangers or any other system.

PREFERRED EMBODIMENT OF THE INVENTION

The present invention discloses a new type of instantaneous water interaccumulator for sanitary or industrial consumption, which presents a technical novelty with respect to traditional systems of production and accumulation of ACS, managing to solve all the problems generated by traditional installations.
The invention facilitates the use of solar equipment or heat recovery, reducing the operational cost of the installation. It eliminates the installation of plate heat exchangers, with the consequent economic savings in their installation cost, maintenance, and heat losses. The primary fluid is contained in the interaccumulator envelope and allows heating/cooling of the secondary fluid, usually water for human consumption.
The interaccumulator of the invention incorporates an inlet (A) of the fluid to be heated/cooled at the top of the structure and an outlet (B) of the hot/cold fluid arranged on one side of the bottom of the structure. It also includes an inlet distributor (1) of the fluid to be heated/cooled and an outlet distributor (2) of the hot/cold fluid, a purge outlet (3) arranged at the bottom of the structure for multiple uses that allows the purging and emptying of the fluid, a probe socket (4) arranged at the top of the structure for multiple uses such as purging and filling the fluid, a plurality of entries and exits (5) for the primary fluid, arranged on one of the sides of the structure of said interaccumulator, an interaccumulator envelope (6) of any material that supports the physicochemical characteristics of the primary fluid and stylized both for heating and for cooling the secondary fluid and supports the internal and external components, a thermal protector (7) that allows the thermal insulation of the whole set to make its operation more efficient, at least one interior coil (8a), and at least two exterior coils (8b), where said coils (8a) and (8b) are corrugated and have the same length.
The need for the coils (8a) and (8b) to be corrugated is due to the fact that, for the same length of coil, the corrugated design has a much larger contact surface area between the fluids than if the coil were smooth. Heat exchange occurs through contact, and the larger the contact surface area, the more heat will pass from one fluid to the other. Additionally, being corrugated, the coil has the ability to increase its length through thermal expansion with variations in temperature, making it more difficult for limescale deposits to form. These deposits typically become partially detached due to these contractions and expansions, delaying the onset of faults due to this reason. Furthermore, having corrugated coils (8a) and (8b) reduces the probability of failure in the event of a fault in the installation tank. This is because the increase in volume due to a localised increase in water temperature can be absorbed by the coils, delaying the increase in pressure and hence additional damage to the installation.
It is important that the length of the coils be equal so that the flow of water, as well as the flow rates and retention times of the fluid in the tank, are similar.
Each of the different coils are manufactured in stainless steel corrugated pipe, which together with the inlet and outlet distributors, make up the internal hydraulic system.
The insulation used can be rigid or flexible and of various thicknesses, allowing the equipment to adapt to different locations (indoor or outdoor, cold or warm environments, wider or narrower passages).
The interaccumulator allows for the incorporation of multiple lateral outlets to be used as probes, viewers, auxiliary outlets, fillings, etc.
The innovative interaccumulator of the invention has a very low total volume/instantaneous flow rate ratio, allowing it to replace traditional accumulators of large volume, that is, greater than 2000 liters, with interaccumulators of 800 liters with a much higher instantaneous availability of hot water than the traditional accumulator. This fact makes it very easy to introduce a tank during the construction of a building and build around it, for existing installations that need to replace deteriorated traditional tanks, where the main problem is to remove the current accumulators and replace them with others of the same size, due to the logistical problems that this entails. This results in significant cost savings by avoiding complicated logistics.
In the invention's interaccumulator, the domestic water never comes into contact with the steel casing (6), and since there is no flow or accumulation of hot water for human consumption, there is no need to install any sacrificial or electronic anodes to prevent corrosion of the casing. This represents a significant cost saving in external elements that are not necessary to install or maintain. Additionally, the interaccumulator is compatible with different energy sources such as heat pumps, boilers, and solar energy.
The casing (6) can be made of any material that can withstand the temperatures and qualities of the primary fluid, as its only functionality is to contain the primary fluid and allow connections of pipes and probes.
The connecting elements between the pipes outside the casing (6) and the coils (8a) and (8b) are made of stainless steel, eliminating the risks of Legionella.
The innovative interaccumulator simplifies systems for water recirculation between tanks, avoiding stratification and "dead" zones, resulting in lower installation costs, simpler maintenance, less likelihood of breakdowns, and lower energy costs.

Claims

Instantaneous fluid interaccumulator for human consumption and/or food fluids characterized in that it comprises an inlet (A) for the fluid to be heated/cooled at the top of the structure and an outlet (B) for the hot/cold fluid arranged on one side of the bottom of the structure; an inlet distributor (1) for the fluid to be heated/cooled and an outlet distributor (2) for the hot/cold fluid; a drain (3) arranged at the bottom of the structure; a probe port (4) arranged at the top of the structure; a plurality of primary fluid inlet and outlet ports (5) arranged on one side of the interaccumulator structure; an interaccumulator casing (6) that allows heating and cooling of the secondary fluid; a thermal protector (7) that allows thermal insulation of the entire assembly; at least one inner coil (8a); and at least two outer coils (8b), where said coils (8a) and (8b) are corrugated and have the same length.
Instantaneous fluid interaccumulator for human consumption and/or food fluids according to claim 1, characterized in that it incorporates multiple lateral ports for use as probes, sight glasses, auxiliary ports, fillings, etc.
Instantaneous fluid interaccumulator for human consumption and/or food fluids according to claim 1, characterized in that the connector elements between the pipes outside the casing (6) and the coils (8a) and (8b) are made of stainless steel.
Instantaneous fluid interaccumulator for human consumption and/or food fluids according to claim 1, characterized in that rigid insulation can be used.
Instantaneous fluid interaccumulator for human consumption and/or food fluids according to claim 1, characterized in that flexible insulation can be used.
Instantaneous fluid interaccumulator for human consumption and/or food fluids according to claim 1, characterized in that each of the different coils (8a) and (8b) is made of corrugated stainless steel.