WO2019112409A1

WO2019112409A1 - High-pressure water storage tank for solar heaters

Info

Publication number: WO2019112409A1
Application number: PCT/MX2017/000143
Authority: WO
Inventors: Jorge Adrián MARTÍNEZ SILVA
Original assignee: Martinez Silva Jorge Adrian
Priority date: 2017-12-04
Filing date: 2017-12-04
Publication date: 2019-06-13

Abstract

The present invention relates to a solar collector or solar heater for water, wherein a water storage tank stores the hot water by means of continuous heating, does not receive solar radiation and prevents the water from losing heat.

Description

HIGH PRESSURE WATER STORAGE TANK

FOR SOLAR HEATERS

TECHNICAL FIELD

The present invention belongs to the field of solar water heaters, more specifically to the development of tank or hot water tanks that support high pressure for the preservation of the temperature of the hot water obtained in the solar heater itself.

BACKGROUND:

Solar water heaters for human consumption have been known for more than a century, constituting one of the best solutions for heating a liquid in an economical and friendly way with the environment. Consequently, there is a large number of solar heaters in the state of the art which are inefficient in the way of conserving the heat stored in the liquid when the ambient temperature drops. Solar water heaters typically consist of two main structural elements; the solar collector that is responsible for capturing the sun's energy and transferring it to the water; The second element is the tank or storage tank for hot water for later distribution. Said second element, also called hot water tank, consists of an internal tank normally made of metal or some polymeric material, which is thermally insulated, and an outer casing.

Thermostats are often also the reservoir for the cold water that will be heated, so that the hot water moves to the top of the tank, due to the density gradient created by temperature differences. The solar heaters that work a pressurized hydraulic network.

Consequently, the solar water heaters described in the state of the Technicians have as one of their main problems the efficiency in the preservation of hot water for long periods of time, 12 or more hours, as well as resisting high pressure coming from the hydraulic network. Said problem has been solved through various mechanisms, which range from using black-painted hot water tanks, coating the tank with black plastic films or polyurethane insulating layers or developing more complex coatings, as well as the use of pressure relief valves such as described in the following publications. The patent MX228503, HEATER-TANK-THERMO-SOLAR. Describes a solar heater where it is possible to heat liquids (such as water), with solar energy, at 40 ° C or more and maintain it at 40 ° C for 20 hours or more, using the concept of storage and heater in the same appliance, the which consists of a plastic tank covered with transparent plastic caps also containing a fluid by spitting with a black metal plate capturing solar radiation, a system of preheating to avoid a thermal short circuit, all thermally insulated.

The application MX / a / 2014/012207, SOLAR HEATER WITH LOW THERMAL LOSSES AND METHODS OF INSTALLATION THEREOF, provides a solar heater constituted by a base and an outer cover, the base houses an electrical resistance, a cold liquid inlet pipe and a hot liquid outlet tube. The cover houses inside a cylindrical solar absorber formed by an absorption surface that has inside one or more spacers that allow a liquid chamber to exist between the inside of the absorption surface and the outside of a thermo-tank .

In the patent MX151700 IMPROVEMENTS IN SOLAR HEATER, reference is made to improvements in solar heater of the type comprising a flat collector of solar energy, based on a thermally insulated frame, a transparent top cover and a collector plate of parallel sheets, a container or thermally insulated storage tank; two fluid conductors that collect the collector with the tank; a unidirectional valve inserted in one of the ducts and a mirror placed on the upper edge of the collector.

Regarding solar heaters focused on solving the high pressure problem, the application MX / a / 2014/005645: SOLAR WATER HEATER SUPPORTING HIGH WORKING PRESSURES WITH DOUBLE INDIRECT HEATING CIRCUIT AND ELECTRICAL AUXILIARY REINFORCEMENT OF HIGH ENERGY EFFICIENCY, refers to a solar water heater that supports high working pressures with double indirect heating circuit and high energy efficiency auxiliary electric reinforcement with a thermally isolated metal tank with thermal insulation of pre-molded hemispheres of low density polystyrene. Designed to work in hydraulic networks at gauge pressure up to 11 kg / cm2, it has an auxiliary electric heating device that limits the maximum temperature range of the water to be consumed to not exceed 600 ° C, taking into account the levels of insolation.

In CN304240467, CN203628819 discloses pressure-supporting solar water heating systems, comprising a water storage unit, a solar heat collection unit, a cold water pipe, a hot water pipe and a controller, where the water storage unit comprises a water reservoir and a heating element disposed in the water reservoir supporting pressure. In CN 103822295 there is disclosed a solar water heating system that supports pressure comprising a water storage unit which comprises a pressure support water tank, a solar heat collection unit, a cold water pipe, a hot water pipe and a controller. US4240405 patent provides a solar water heater including a pressure accumulator and a steam release drum; US4237862 discloses a closed pressurized solar heating system in which a solar collector is automatically drained of heat transport fluid independently of the valve actuation or valve position.

The solar heaters of the state of the art pretend to solve preferably to solve the problem of preservation of the temperature of the water or high pressure management from the hydraulic or internal network, consequently it is necessary to have solar radiation collection systems that solve both problems at the same time. The present invention is directed to provide a water storage tank for solar heaters with a thermal coating, which also support high pressures of the hydraulic network, as well as the process of manufacturing said hot water tank. BRIEF DESCRIPTION OF THE FIGURES

Figure 1 This is a bottom view of the tank where T indicates the outer tank. The view shows the 3 perforations (a, b, c) that both tanks carry in the lower part.

Figure 2 The illustration shows a section of the tank in which we can see the interior, in which "2" indicates the internal tank, "8" indicates the space between both tanks that is covered by the insulating compound (polyurethane foam) .

Figure 3 a side view of the tank where it shows the first end, in which we can see the first end of the tank where is the nipple that is connected to the cold water pipe that supplies the tank.7 pressure valve Figure 4 View front of the tank, observe the 5 connections of the tank (four nipples and one valve), starting with the first end "3" the first nipple that supplies the cold water to the tank. "4" second nipple of the tank, which supplies the cold water to the solar heater, "5" third nipple, which transports the hot water from the solar heater, to the tank. "6" fourth nipple, which is connected to the pipe that distributes the hot water. 7 pressure valve which is connected directly to the insert placed in that location of the tank.

Figure 5 Top view of the internal tank that illustrates the position of the pressure valve (7).

Figure 6 Top view of the internal tank, in which the location of the insert (7) that serves to connect the pressure valve is shown. Figure 7 Side view of the inner tank, in the lower part the perforation (8) in which the first insert of the tank is placed can be seen.

Figure 8 Front view illustrating the shape of the tank and the reliefs (9) in which the hexagonal inserts are placed (d, e, f,) Figure 9 Illustration of the internal tank which shows the lower part of the tank and they appreciate the three holes in which the hexagonal inserts (g, h, i, j) are placed for the different connections of the tank.

Figure 10 Isometric view of the tank, in which the shape of the inner tank can be appreciated. Figure 11 Bottom view of the external tank, in which the 3 holes in the lower part corresponding to the location of the internal tank inserts (d, e, f or g, h, i, j) can be observed, as well as allows observing the placement of the inserts that are fixed to the base (k, I, m, n).

Figure 12 Top view of the tank illustrating the location of the hole (7 ') in which the pressure valve is placed.

Figure 13 Front view of the tank that allows us to see the cylindrical shape of it.

Figure 14 Front view of the tank lid.

Figure 15 Side view of the lid that allows us to see the size of the lid

Figure 16 Side view of the tank in which the location of the perforation (10) of the first end of the tank is observed.

Figure 17 Illustration of a brass insert with internal thread that serves as a connection to the tank in which the stainless steel nipples are assembled.

Figure 18 Drawing of stainless steel nipple with external thread on both ends which serve to make the connection of the tank to a hydraulic network. Figure 19 is a diagram of the operation of the flat solar water heater system and water container: 1 container or water tank; 2 the cold water goes through the heater pipe; 3 the cold water is concentrated in the lower part of the tubes; 4 in the upper part of the tubes is the hot water; 5 the hot water is stored in the tank at the top; and 6 hot water outlet.

Figure 20 shows the interior of the flat heater: 1 Input connection; 2 Absorbent plate protection cover that prevents heat loss; 3 output connection; 4 absorber plate: usually a black absorbent chrome coating to maximize the efficiency of heat collection; 5 Insulation: on the bottom and sides of the collector to reduce heat loss; 6 flow tubes; 7 Collector housing made of aluminum alloy or galvanized alembic - fixed and protects the absorber plate.

Figure 21 shows a section of the flat collector: 1 glass; 2 absorber; 3 Isolation; 4 black sheet; 5 Lifting tube; 6 Head tube; 7 aluminum rails.

Figure 22 illustrates the shape of the heater head (11) Figure 23 shows the plurality of tubes that perceive solar radiation.

Figure 24 shows the head (12) on which the water is heated, and shows the connection (13) between the entrance of the copper rods of the heater.

Figure 25 shows in detail the interior of the heat exchanger or head (14) in the upper part of the tube heater.

DESCRIPTION OF THE INVENTION

The present invention relates to a solar water heater or collector comprising a hot water tank or container or container of water of high pressure. The actual heater, can be of the flat type or panel composed of a metallic structure, figure 2, in the form of a box which has in the lower part a layer of thermal insulation, followed by a metal sheet painted with a layer of metallic paint (aluminum with sulfur) to absorb the greatest amount of heat, on top of this sheet is dyed a copper pipe containing water, said The pipe is heated and conducts the heat to the water. In the upper part and also serves as a lid is a crystal which filters the radiation of the sun. The collector has an inlet and a water outlet. The inlet and outlet are connected to the thermostat, the water inlet goes from the lower part of the tank to the inlet of the head, and the outlet is connected to the upper part of the thermostat, figures 3 and 4.

In a second mode the solar heater is made of tubes, which consists of a copper conduit where the water is heated in the pipe by means of copper rods that are in contact with the pipe through which the water constantly passes. These copper rods contain a cooling liquid, these rods are inside a vacuum tube, which filters the solar radiation and transmits the heat to the copper rod, similar to a series of electrical resistances which are heated up to 180 ° C in a tube and heat the water that passes through the tube. Figures 6 to 9 show the head and details the connection of the rods to the tube containing the head, said head is composed as follows: there is a tube in the middle of the metal cover that is seen, the space between the tube and the cover is filled with thermal insulation, except for the space where the copper rods that heat it are connected. The head has an inlet and a water outlet. The entrance and exit are connected to the thermostat, the water inlet goes from the lower part of the tank to the inlet of the head, and the outlet is connected to the upper part of the thermostat.

The heating tube is a double-walled tube from which the air is extracted from between both walls and is vacuum sealed, the outer wall of the tube filters the sun's radiation and the inner layer is painted with a metallic paint which absorbs the heat of solar radiation. The interior of the heating tube contains a copper rod containing glycol (pe 193 ° C), this coolant maintains the heat of the rod for longer, inside the hot water tank exchanges heat with the water contained therein, the copper rods heat the water contained in the thermo-tank as. The hot water is kept in the upper part of the thermo tank due to the density difference due to the temperature. Once the temperature of the water in the tank is homogenized, it is maintains by the continuation of the cycle: water of low temperature and greater density goes to the bottom of the tank and from there to the solar heater, once it reaches a certain temperature returns to the storage tank. In both cases, the heater has an inlet and a water outlet. The inlet and outlet are connected to the tank, the water inlet goes from the bottom of the tank to the inlet of the heater and the outlet is connected to the top of the tank. The water storage tank is fed by a pressurized hydraulic network, it stores the hot water by the continuous heating produced by the solar collector, but it does not receive the solar radiation, however, it avoids the heat loss of the water. The temperature that can be reached with the glycol-containing tube heater inside the heater allows the water in the hot water tank to reach between 60 ° C and 90 ° C, and withstands pressures of up to 6kg / cm ² (84 psi). It also provides hot water to the pressurized hydraulic network.

The tank or water container comprises: an internal tank; Polyurethane foam; an external tank; a plurality of Nipples for connection of STAINLESS STEEL NPT; a plurality of hexagonal screws for base; a plurality of NPT rope brass inserts and a plurality of fine rope Brass inserts; a pressure releasing valve;

The inner and outer tanks are manufactured by rotomokJeo with a resin selected from the group of polymers comprising polyethylene, polypropylene, polyvinyl chloride, nylon and polycarbonate, in all the densities of each of these materials that are useful for manufacturing by rotomolding. The resin must have an impact resistance according to its properties 45 Ib / ft ² being at low temperature -40 ° C according to the procedure of the ARM I (Association of Roto Moldeadores International), with such a thickness and applying the process necessary for the internal and external tank to retain the cylindrical shape without suffering deformations, in addition the internal tank withstands hot water up to a temperature of 90 ° C and pressures of up to 4.5 kg / cm ² . and in such a way the tanks internal and external retain the cylindrical shape without undergoing deformations; In addition, the internal tank withstands hot water up to a temperature of 90 ° C. The inner tank is manufactured in one piece by the rotomolding process, has a thickness of approximately 10mm +/- 5mm.

The hexagonal brass inserts of different sizes are integrated into the plastic tank during its manufacture by rotomolding.

The internal tank has 5 matching inserts with 5 perforations in the outer tank; in the hexagonal inserts of the inner tank are mechanical joints by means of a thread, in the inserts are placed threaded nipples which pass through the insulation layer and the external tank, these are installation connections that are in different placements, in the first instance, one side of the tank has the first connection, in the lower part there are 3 more connections that we can number from 2 to 4 starting from the end where the first connection is. The fifth connection itself is in the upper part of the tank.

In addition, at a first end the internal tank has a perforation located on one side of the tank, in said perforation a first hexagonal insert is placed where a first nipple is also placed; in said first nipple it is connected to the pipe that supplies the cold water to the tank. A second perforation is at a distance from a first end, in said perforation a second hexagonal insert is placed where a second nipple is also placed; in said nipple a hose is connected which supplies water from the tank to the heater. A third perforation is located at a distance from a first end, in said perforation a third hexagonal insert is placed where a third nipple is also placed; in said nipple a hose is connected, which serves for the solar heater to supply the hot water to the tank. In the lower part it has a fourth perforation at a distance from a first end, in said perforation a fourth hexagonal insert is placed where a fourth nipple is also placed; in this nipple the pipe that distributes the hot water is connected; and in the upper part has a fifth perforation at a distance from a first end, in said perforation a fifth hexagonal insert having an internal thread is placed; in said insert connects a valve that regulates the pressure and temperature inside the tank.

The outer tank is composed of a body and a cover, which are welded to form the outer tank; said body and cover are manufactured in the same rotomolding process, have a thickness of approximately 4mm +/- 0.5mm; said lid is welded to the tank body in a uniform manner and without visible defects. The polyurethane foam insulation consists of a mixture of polyol and isocyanate with a high density and better thermal insulation; said foam is between both tanks and has a thickness of approximately 50mm +/- 10mm.

The manufacturing process of the water tank includes the steps of placing the inserts in a cylindrical mold in the corresponding location and pouring resin selected from the group of polymers that are useful for manufacturing by rotomolding (polyethylene, polypropylene, polyvinyl chloride, nylon and polycarbonate, in all the densities of each of these materials) for the manufacture of a first hollow interior tank of cylindrical shape. Once the resin is solidified, the tank is demolded, air is injected inside and all the holes are sealed under pressure to check that the tank does not leak.

The inserts are placed in a mold in the corresponding location and the selected resin is poured from the group of polymers that are useful for the manufacture by rotomolding (polyethylene, polypropylene, polyvinyl chloride, nylon and polycarbonate, in all the densities of each one of them). these materials) for the manufacture of a second hollow outer tank of cylindrical shape.

Once the resin has solidified, the second outer tank is demolded and an end is cut to obtain the body of the external tank and the lid, the burrs are eliminated and the cut is outlined.

Place the first inner tank inside the second outer tank, attach the assembled nipples in the internal tank inserts to the external tank and pass through the matching external tank orifices of the external tank to keep the tanks volumetrically centered. Place the dust covers on each of the nipples, tighten the nipples and fill the space between the tanks with the liquid polyol and isocyanate mixture between the two tanks.

The outer tank lid is then placed and the mixture is allowed to cure, then the lid is welded to the outer tank body with a solder of the same material. The water container tank of the present invention offers the advantages of achieving a shorter heat recovery time of the water coming from the solar heater, less loss of heat in the tank, greater durability up to 30 years, more hygienic materials since the tank does not Adhere impurities

Claims

A solar water heater characterized in that it comprises a hot water tank or container or high pressure water tank and a solar heater, wherein the solar heater is selected from a panel or flat heater and a vacuum tube heater; and the high pressure water tank includes a first interior tank, a thermal insulator, a second external tank and accessories to join the solar heater.

2. The solar heater according to claim 1, wherein the heater is a metal structure in the form of a box that at the top has a lid with a crystal, said crystal filters the solar radiation; the inner part is painted with a metallic paint which absorbs the heat of the radiation. This is in charge of heating a copper pipe that is between both layers. This pipe contains water and begins to heat the water it stores.

The solar heater according to claim 1, wherein the hot water tank of the solar heater stores the hot water in continuous heating, does not receive the solar radiation and prevents the loss of heat from the water; In addition, the water tank includes a first tank or inner tank, a second tank or outer tank, both manufactured from the resin selected from the group of polymers that are useful for manufacturing by rotomolding (polyethylene, polypropylene, polyvinyl chloride, nylon and polycarbonate, in all the densities of each of these materials), and between both tanks is a polyurethane thermal insulation.

The solar heater according to claim 1, characterized in that the inner and outer tanks are manufactured by rotomolding with a resin selected from the group of polymers comprising polyethylene, polypropylene, polyvinyl chloride, nylon and polycarbonate, in all the densities of each of these materials that are useful for manufacturing by rotomolding; said resin resists at least one impact of and in such a way the internal and external tanks retain the cylindrical shape without undergoing deformations; In addition, the internal tank withstands hot water up to a temperature of 90 ° C.

5. The solar heater according to claim 1, characterized in that the internal tank has 5 matching integrated inserts with 5 perforations in the outside tank; in the hexagonal inserts of the inner tank are mechanical joints by means of a thread, in the inserts are placed threaded nipples which pass through the insulation layer and the external tank, these are installation connections that are in different placements, in the first instance, one side of the tank has the first connection, in the lower part there are 3 more connections that we can number from 2 to 4 starting from the end where the first connection is. The fifth connection itself is in the upper part of the tank.

The solar heater according to claim 1, characterized in that the internal tank at a first end has a bore located on one side of the tank, in said borehole is placed a first hexagonal insert where a first nipple is also placed; in said first nipple it is connected to the pipe that supplies the cold water to the tank.

The solar heater according to claim 1, characterized in that the internal tank in the lower part has a second perforation at a distance from a first end of the tank, in said perforation a second hexagonal insert is placed where a second nipple is also placed; A hose is connected to the nipple, which supplies the cold water to the solar heater.

The solar heater according to claim 1, characterized in that the internal tank in the lower part has a third perforation at a distance from a first end, in said perforation a third hexagonal insert is placed where also a third nipple is placed; in said nipple a hose is connected, which serves for the solar heater to supply the hot water to the tank.

The solar heater according to claim 1, characterized in that the internal tank in the lower part has a fourth perforation at a distance from a first end, in said perforation a fourth hexagonal insert is placed where a fourth nipple is also placed; The pipe that distributes the hot water is connected to said nipple.

The solar heater according to claim 1, characterized in that the internal tank in the upper part has a fifth perforation at a distance from a first end, in said perforation is placed a fifth hexagonal insert that they have an internal thread; A valve regulating the pressure and temperature inside the tank is connected to said insert.

11. The solar heater according to claim 1, characterized in that the inner tank is manufactured in one piece by the rotomolding process, has a thickness of approximately 9mm +/- 1 mm.

12. The solar heater according to claim 1, characterized in that the outer tank is composed of a body and a cover, which are welded to form the outer tank; said body and cover are manufactured in the same rotomolding process, have a thickness of approximately 4mm +/- 0.5mm; said lid is welded to the body of the tank uniformly and without visible defects.

The solar heater according to claim 1, characterized in that the polyurethane foam insulation consists of a mixture of polyol and isocyanate with a high density and better thermal insulation; said foam is between both tanks and has a thickness of approximately 50mm +/- 10mm.

14. A tank tank tank manufacturing process comprises the steps of: a) Place the inserts in a cylindrical mold in the corresponding location and pour resin selected from the group of polymers that are useful for rotomolding production (polyethylene, polypropylene, polyvinyl chloride, nylon and polycarbonate, in all the densities of each of these materials) for the manufacture of a first hollow interior tank of cylindrical shape. b) Unmold the tank and inject air inside and with all the holes sealed under pressure to check that the tank does not show leaks. c] Place the inserts in a mold in the corresponding location and pour the resin selected from the group of polymers that are useful for the manufacture by rotomolding (polyethylene, polypropylene, polyvinyl chloride, nylon and polycarbonate, in all the densities of each one of them). these materials) for the manufacture of a second hollow outer tank of cylindrical shape. d) Unmold the second outer tank and cut one end to obtain the external tank body and cover, burrs are removed and the cut is outlined. e) Place the first inner tank inside the second outer tank, attach to the external tank the nipples assembled in the internal tank inserts and pass through the matching external tank orifices of the external tank to keep the tanks volumetrically centered. f) Place dust covers on each of the nipples, tighten the nipples. g) Fill the space between the two tanks with the polyol and liquid isocyanate mixture. h) Place the outer tank lid and allow the mixture to cure and weld the lid to the outer tank body with a solder of the same material.