FR2492955A1 - Solar-powered central heating system - has air circulated to heat accumulator fitted in base of building after heating - Google Patents

Abstract

The solar central heating system for air in a building has a heat accumulator in the basement (3). There is a hot air circuit heated by captors (4). The accumulator is divided into three layers, a lower one for air circulation, a stack (7) of sealed containers with liquid or solid, with air between and an upper air circulating port (6). The upper part is divided by a partition (8) with a controlled air valve (9). There are several air channels (10) connecting the captor outlet (28) to the accumulator top and channels (11) joining the accumulator base (5) to the captor entry (27).

Description

Solar central air heating of a building
The invention relates to a complete and coherent system for heating a building partially by solar energy using solar air sensors.

 Existing solar heating techniques follow two main branches, one using water and the other air, as the heat transfer fluid.

 The advantages of water are well known, and in particular the comfort of heating by heat radiation. But its drawbacks are no less so, notably the risk of freezing, and that, which is more difficult to combat corrosion.

 The advantages of air systems are robustness, low thermal inertia, and their lower construction cost.

 Among the techniques used in air systems, there are passive systems which are difficult to control, and active systems, more or less sophisticated in their arrangement and regulation.

 These systems often have a single air circuit for both collection and heating. Their drawback is that they cannot capture energy in low sunshine and cold weather because the temperature of the air at the outlet is too low for this air to be used directly for heating. This results in considerable loss of capture time.

 The object of the invention is to remedy these drawbacks, as part of a complete and consistent solution of solar air heating of a building.

 The invention therefore relates to the arrangement of the various elements that make up the system.

 According to the invention, the heating installation is composed of two independent air circuits as to their operation, one for the production of hot air by the sensors, the other for the distribution of air. hot in the heated premises of the building. These two circuits intersect inside the heat accumulator.

 The particular advantage of the invention is to be able, under certain conditions, to distribute air in the rooms to be heated, at a temperature higher than that obtained at the output of the sensors, while continuing to produce usefully energy from the sensors.

 The system includes - A battery of solar air collectors (4), placed on the building (1) or in the immediate vicinity, on a higher or lower level or on the front of the building. In the attached diagrams, the sensors have been immagined, for example, on the roof.

 The sensors are preferably oriented full south, with a tolerance of a few degrees east or west. Special mask or micro-climate conditions may make it prefer a south-east or south-west orientation.

 The most favorable inclination of the sensors with respect to the horizontal axis is given in degrees by the lattitude of the place increased by approximately 15. It is however possible, by accepting a drop in the annual performances, to adopt an inclination of lower or higher value.

- A heat accumulator (2) must be placed on a level below the premises to be heated (3) or under these premises.

 The accumulator is, according to the invention, a closed and thermally insulated room, having all the guarantees necessary to be valid - as considered capable of transporting the air then distributed in inhabited rooms, which excludes the simple crawl space on clay.

This room (2) is divided into three superimposed spaces, which are from bottom to top
- firstly, a lower space (5) for air circulation
- secondly, a stack (7) of closed containers containing a heat accumulating liquid (water or material with high latent heat of fusion and low melting point). These containers, of any shape and material resistant to the expected temperature, leave air passages at their periphery, so as to allow heat exchanges between the air and the contents of the containers. Many commercial containers are usable, including glass bottles and some plastic bottles, and containers used in the transport of wine, oil, or any other fluid. The volume of the containers does not exceed - not 50 liters so that the heat exchange can take place with air, but it will advantageously be of the order of 5 to 10 liters.

 - thirdly an upper space (6) for air circulation. One of the characteristics of the invention is that this upper space (6) is divided into two parts by a vertical partition (8) provided in its surface with an air passage equipped with a motorized shutter (9) for controlling air flow. This flap can be completely open or completely closed or in any intermediate position.

- One or more air circulation ducts (11) which connect the lower space (S) of the accumulator to the input (27) of the sensors. A dust filter, not shown in the diagrams, equips this sheath (11) to protect the sensors.

- A fan (12), turbine, or other device for forced air circulation, is placed in this sheath (11). Its flow is adjustable and subject to regulation.

- An outside air intake (22), connected to the sheath (ii) by means of a motorized selector flap (23) located between the fan (12) and the input (27) of the sensors. This air intake makes it possible to ensure the natural ventilation of the sensors outside of their period of use, this in order to avoid condensation inside the sensors when it can be harmful.

- A sheath (10), or several sheaths, which connects the outlet (28) of the sensors to the upper space (6) of the accumulator.

- A sheath (24) for evacuating the collectors' ventilation, connected to the sheath (10) near the outlet (28) of the collectors, by means of a motorized selector shutter (25).

- A duct (13) for ejecting hot air, connected to the duct (10), between the flap (25) and the upper space (6) of the accumulator, by means of a selector flap (14) motorized. This sheath is intended for summer use.

- A distribution duct (15) of air in the premises (3) to be heated, of sufficient size for thermosyphon operation of this distribution, connected to the upper space (6) of the accumulator.

This sheath can be divided into several branches according to the needs of the architecture of the building,
It receives air diffusion vents (16) fitted with motorized flow control flaps.

 Inside this sheath (15) and in its lower part is located the heat exchanger (19) of an additional heating device, which consists of one or more electric convectors, or a water heat exchanger -air supplied by a boiler or a chimney, or even the condenser of a heat pump.

 The sheath (15) is equipped with a dust filter not shown in the diagrams.

 An important feature of the invention is that the duct (15) for air distribution and the duct (10) for producing hot air from the sensors, are connected to the upper space (6) of the heat accumulator. on either side of the partition (8) which separates the said upper space (6) of the accumulator in two.

- One or more return air circuits (17) in heated rooms.

These circuits make maximum use of the natural circulation of the building, corridors, stairs, etc., or failing this, the air circulation ducts which are reserved for them and which capture air in the lower parts of the heated premises.

- Temperature probes (30), (31)> (33); (34), (35), (36), (37) (38), (39), as indicated in diagram I and in the legend of the diagrams, which are placed at the control points and connected to the regulation.

- An air flow telemetry device (32), placed at the outlet (28) of the sensors and connected to the regulation. Indeed, the hot air flow intervenes in the processing of information by the regulation for the modulation of the air flow of the fan (12).

- A control unit, not shown in the diagrams, which takes into account the parameters of temperature and air flow, and the temperature and time programming instructions for the temperatures of the heated rooms, to manage the production of hot air , the storage of heat in the accumulator, and the distribution of hot air. It acts on the fan (12), the motorized shutters (9), (14), (23), (25), the air diffusion vents with motorized shutters (16), and the additional heating (19). It also allows automatic snow removal of coaptors.

The description of the arrangement of the system being completed, the different phases of its operation are to be considered, depending on the sunshine, the average temperature of the heat accumulator, the temperature of the premises to be heated. , and the season
In winter, in sunny weather, there is solar energy collection and simultaneously space heating; the system works then according to diagram 1
The selector flaps (14), (23), and (25) are positioned as shown in diagram 1 and thus allow air circulation throughout the heat production circuit, from the lower space (5) of the accumulator by the sheath (11), the sensors (4), and the sheath (10), up to the upper space (6) of the accumulator.

 The fan (12), the operation of which is authorized and modulated by the regulation, circulates the air in the hot air production circuit.

 The fresh air coming from the lower space (5) of the accumulator is heated by the sensors (4) and the hot air thus produced is sent to the upper space (6) of the accumulator; the hot air passes through the active part of the accumulator constituted by the stack (7) of containers, and thanks to the heat exchange on the walls of the containers, heats their contents, before reaching the lower space (5 ) of the accumulator, and to leave via the sheath (11) in the hot air production circuit.

 The distribution of hot air in the premises (3) to be heated is made by the distribution sheath (15), in thermosyphon, from the upper space (6) of the heat accumulator. The air diffusion vents (16) distribute in each room the necessary and sufficient quantity of hot air thanks to their control flaps controlled by the regulation.

 The cold air of the premises (3) is taken up in their lower part, by thermosyphon in the circuit (17) of air intake, to return to the lower space (5) of the accumulator.

 It is important, according to the invention, that as a function of the temperature of the hot air produced by the sensors and measured by the probe (33), as a function of the temperature of the upper receptacles of the stack (7) measured by the probe (36) and depending on the temperature of the air in the upper space (6) of the accumulator measured by the probe (34), the regulation controls the opening or closing of the flap (9) flow control.

 This is one of the advantages of the invention, which allows, by opening the flap (9) to directly benefit for the heating of an air sufficiently heated by the sensors (4), and by closing the flap (9) take advantage of a high temperature in the upper receptacles of the accumulator despite a lower temperature at the sensor outlet. It should be noted that this combination allows transient situations, such as the start-up of the capture installation in the morning, without the disadvantage of a cold air purge by the air distribution circuit in the heated premises, and therefore without destabilizing the regulation of the system.

 Whatever the temperature of the air in the upper space of the accumulator, and therefore whatever the conditions for collecting solar energy and level of energy filling of the accumulator (7), the additional heating (19) ensures that the air supplied by the duct (15) is kept at the desired temperature, thanks to the temperature probes (34) and (35) located upstream and downstream of the additional heating in the duct (15 ), and to the outside temperature probe (39), all of the information being processed by the regulation.

 The domestic hot water is heated by means of the air-water heat exchanger (20) placed in the sheath (10).

 The exchanger is connected to the storage tank (26) of domestic hot water, by a circuit operating as a thermosyphon according to diagram 1, but which can be fitted with an electric circulator, not shown, depending on whether or not it is possible to place the balloon (26) above the exchanger (20). it is obvious that the installation includes all the necessary and well-known organs for any production of hot water, expansion tank, safety group, drain, etc.

 Complementary heating of a sanitary hot strip produced by this solar energy installation is supplied in series at the outlet of the solar tank (26) so as to maintain the temperature of the water during use at a chosen set point. . It is important that this heating supplement is instantaneous, without significant reserve of hot water. The complementary energy can be electricity, or gas, or any type of boiler, in particular that which could supply the exchanger (19) for the additional heating of the premises (3).

 In winter, and in the absence of sun, or more generally when the production of hot air by the sensors drops below a threshold of quantity of energy, and / or a threshold of temperature, recorded in the regulation or calculated by it according to the different temperatures measured by the probes, the collection process is interrupted. The ventilator (12) is stopped and the selector flaps (23) and (25) cut the hot air production circuit, upstream and downstream of the sensors, according to diagram 2.

 The hot or warm air from the accumulator is thus trapped inside the building, and the sensors are naturally ventilated like an ordinary roof.

 Note that this ventilation can in some cases be optional if one does not fear the effects of condensation, and in particular when the sensors are designed for the purpose in order to support and collect the condensed water, or are arranged in a slope under the building, without risk of damage to the thermal insulation of the sensor, or to the elements below.

 The distribution of hot air in the rooms (3) to be heated, in the case of this diagram 2, where the sunshine is insufficient or zero, is done in the same way as in the case of diagram 1, where there has collection and heating simultaneously.

 In both cases, diagram 1 and diagram 2, the introduction of fresh ventilation air is advantageously done in the lower space (5) of the accumulator, by means of the sheath (29) connected to a V.M.C. double flow with heat recovery (21), or, in the case of a V.M.C. without heat recovery, by means of an outside air intake (18).

 In summer, when you want to permanently interrupt the heating of the building, and not to store energy in the accumulator, a voluntary action on a switch in the control box places the selector flaps (14), (23), and (25) in the provisions of diagram 3, and the fan 12 is stopped.

 The daytime heating of the sensors generates an air circulation by thermosyphon according to diagram 3, it being understood that the outlet of the sheath (13) on the back must be located above the low level of the sensors.

 The air is introduced into the building through the doors and windows, and possibly through the fresh air inlet (18), and leaves the balloon water (26) through the exchanger (20 ), the heat taken from the collectors (4). The hot air which then becomes useless, is ejected through the sheath (13).

 Note an interesting possibility of heating the water of a swimming pool, in an air-water exchanger (not shown in the diagrams), placed under the same conditions as the exchanger (20) producing domestic hot water.

 The system thus described in its constitution and operation can be adapted to any type of building, and any type of architecture.

 In the case of collective dwellings, or grouped dwellings, it is important not to mix the air circuits of the different dwellings, but it may be advantageous to geographically group the sensors for architectural reasons, or the accumulators for avoid the multiplication of heat losses.

 Note that if a heat pump condenser is used as additional heating (19), it is advantageous to place the evaporator between the output (28) of the sensors and the selector flap (25) of the output ventilation of the sensors. This takes advantage of the heating, even minimal, of the air in the sensors (4), to improve the performance coefficient of the heat pump.

 The invention thus described also applies to simpli -fied diagrams of the system, which would remain equivalent, and it is in particular possible to remove certain accessories from the circuits and / or means of control and regulation, while retaining the fundamental principles of arrangement of the elements of the system, which constitute the characteristic of the invention.

circuit de production d'air chaud circuit de chauffage du bâtiment extraction d'air vicié dans les pièces humides introduction de l'air neuf circuit de ventilation des capteurs hors utilisation circuit de ventilation estivale du bâtiment et des capteurs (i) - bâtiment (2) - local accumulateur de chaleur (3) - locaux chauffés (4) - capteurs solaires a' air (5) - espace infèrieur de l'accumulateur de chaleur (6) - espace supèrieur de l'accumulateur de chaleur (7) - empilement de récipients (8) - cloison de division de l'espace supèrieur de l'accumulateur (9) - volet motorisé de contrôle de passage d'air (10) - gaine reliant la sortie des capteurs à l'espace supèrieur
de l'accumulateur (11) - gaine reliant l'espace infèrieur de l'accumulateur à l'entrée
des capteurs (12) - ventilateur ou turbine de circulation forcée de 11 air (13) - gaine d'éjection d'air chaud (14) - volet sélecteur de l'éjection d'air chaud (15) - gaine de distribution d1air dans les locaux à chauffer (16) - bouches de diffusion d'air (17) - conduit de reprise d'air dans les locaux chauffés (18) - pénétration d'air neuf (19) - dispositif de chauffage complémentaire (20) - échangeur air-eau de production d'eau chaude sanitaire (21) - installation d'extraction d'air vicié ( V.M.C. ) (22) - prise d'air extèrieur de ventilation des capteurs (23) - volet sélecteur motorisé pour la prise de ventilation 22 (24) - sortie d'air de ventilation des capteurs (25) - volet sélecteur motorisé pour la sortie de ventilation 24 (26) - ballon de stockage de l'eau chaude sanitaire (27) - entrée de l'air dans les capteurs (28) - sortie de l'air des capteurs (29) - gaine d'introduction d'air neuf en provenance de la V.M.C. LEGEND OF SCHEMES

hot air production circuit building heating circuit extraction of stale air in humid rooms introduction of fresh air sensor ventilation circuit not in use summer ventilation circuit of the building and sensors (i) - building (2 ) - heat accumulator room (3) - heated rooms (4) - solar air collectors (5) - lower space of the heat accumulator (6) - upper space of the heat accumulator (7) - stacking of containers (8) - partition dividing the upper space of the accumulator (9) - motorized air passage control flap (10) - sheath connecting the output of the sensors to the upper space
of the accumulator (11) - sheath connecting the lower space of the accumulator to the inlet
sensors (12) - fan or forced air circulation turbine for 11 air (13) - hot air ejection duct (14) - selector flap for hot air ejection (15) - air distribution duct in the rooms to be heated (16) - air diffusion vents (17) - air return duct in the heated rooms (18) - fresh air penetration (19) - additional heating device (20) - exchanger air-water for domestic hot water production (21) - stale air extraction installation (VMC) (22) - outside air intake for ventilation of the sensors (23) - motorized selector flap for air intake 22 (24) - sensor ventilation air outlet (25) - motorized selector flap for ventilation outlet 24 (26) - domestic hot water storage tank (27) - air inlet in the sensors (28) - air outlet from the sensors (29) - duct for introducing fresh air from the VMC

double flow (30) - temperature sensor at the sensor input (31) - air temperature sensor at the sensor output (32) - device for telemetry of the air flow at the sensor output (33) - air temperature sensor arriving from the sensors in
the heat accumulator (34) - temperature sensor of the distributed air, upstream of the heating
additional (35) - temperature sensor of the distributed air, downstream of the heating
complementary (36) - temperature sensor of the upper receptacles of the accumulator (37) - temperature probe of the lower receptacles of the accumulator (38) - ambient temperature sensors of the heated rooms (39) - outdoor temperature sensor

Claims (9)

Claims  1. Central solar air heating of a building, characterized in that it comprises - a heat accumulator (2) disposed in the lower part of the premises (3) heated, or under the said premises; - a hot air production circuit by solar air collectors (4), which crosses the heat accumulator from top to bottom; - a hot air distribution circuit by thermosiphon in the rooms to be heated which passes through the heat accumulator from bottom to top; - a system for regulating the entire system.  2. Solar central air heating of a building, according to claim 1, characterized in that the heat accumulator (2) is a volume divided into three superimposed sections, which are, from bottom to top - a lower air circulation space (5); - a stack (7) of closed containers containing a liquid or a solid and allowing air circulation between the containers; - an upper space (6) for air circulation divided into two by a partition (8) equipped with a motorized shutter (9) for controlling the air passage.  3. Solar central air heating of a building, according to claims 1 and 2, characterized in that the hot air production circuit comprises - a battery of solar air collectors (4); - one or more air circulation ducts (10) which connect the outlet (28) of the solar collectors to the upper space (6) of the accumulator - one or more air circulation ducts (il) which connect the lower space (5) of the accumulator at the input (27) of the sensors - a means (12) of forced air circulation;  a hot air exhaust duct (13) on the outside, fitted with a motorized selector flap (14) when connected to the duct (10) - an outside air intake (22) with selector flap motorized (23) when connected to the sheath (11) near the sensor inlet (27) - an air outlet (24) for ventilation of the co-sensors, with motorized selector flap (25) connected to the sheath (10) near the outlet (28) of the sensors.  4. Solar central air heating of a building, according to claims 1 and 2, characterized in that the hot air distribution circuit comprises: - one or more ducts (i5) for air distribution by thermosyphon, connecting the upper space (6) of the accumulator, to the air diffusion vents (16) in the premises (3) to be heated; - one or more air return circuits (17) connecting the lower parts of the premises (3) to be heated, to the lower lpa (5) of the accumulator - a supply of fresh air for space ventilation lower (-5) of the accumulator.  5. Solar central air heating of a building, according to claims 1, 2 and 4, characterized in that a device (19) provides additional heating in the lower part of the sheath (15) of distribu -ion of air in the premises (3).  6. Solar central air heating of a building, according to all of claims 1,2,3, and 4, characterized in that the connections to the upper space (6) of the accumulator, on the one hand hot air production circuit, and on the other hand the air distribution circuit in the rooms to be heated, are made on either side of the partition (8) which divides the upper space in two (6) of the heat accumulator.  7. Central solar air heating of a building, according to all of claims 1,2,3,4, and 6, characterized by one or several air-water exchangers (20) intended to produce domestic hot water and / or reheating the water of a swimming pool, placed in the sheath (10) which connects the outlet (28) of the sensors to the upper space (6) of the aceumulator, between the selector flap (25) ventilation outlet of the sensors and the selector flap (14) of the hot air ejection.  8. Solar central air heating of a building, according to claims 1 and 4, characterized by the fact that the air outlets (16) of air in the heated premises are equipped with motorized shutters of control of air flow.  9. Solar central air heating of a building according to any one of the preceding claims, characterized by centralized electronic regulation of the entire system, which takes into account parameters of temperature and air flow, as well that threshold and process instructions, and which acts on the motorized shutters, on the operation and the flow rate of the device (12) for forced air circulation in the heat production circuit, and on the operation and running speed of the additional heating.