METHOD FOR COOLING THE AIR OF A BUILDING

Abstract

The subject of the invention is a method for calculating a water outlet temperature of a cold water generator, for an air cooling system of a zone, such as a living room, the system comprising said cold water generator, at least one thermal emitter and a hydraulic circuit for connecting the cold water generator to said at least one thermal emitter, the method comprising the following steps: - calculating a dew point from a value of the air temperature in the zone to be cooled and a value of relative humidity of the air in the zone, and - calculating a outlet temperature, called the optimal outlet temperature, greater than or equal to the calculated dew point. Figure 1

Description

Title of the invention: METHOD FOR COOLING THE AIR OF A BUILDING Technical field

[0001] The present disclosure relates to the field of cooling residential or commercial buildings. Prior art

[0002] Different types of architectures for air cooling systems in a tertiary residential building are known, which hydraulically connect a cold water generator, such as for example a heat pump, an iced water unit or a geothermal device, to energy use equipment, or thermal emitter, such as a floor, a ceiling, a radiator, or even a fan coil.

[0003] These different architectures are all confronted with the appearance of condensates on the thermal emitters when the water outlet temperature is below a threshold value, generally around 16°C. It is then necessary either to operate the cooling system in a limited range of values, above 18°C, or to provide for the evacuation of the condensates. This last option is particularly complicated to implement in pre-existing homes, for which the cooling system is installed to replace an aging installation.

[0004] The aim of the present invention is to at least partially remedy these drawbacks. Summary

[0005] For this purpose, a method is proposed for calculating a water outlet temperature from a cold water generator, for an air cooling system for a zone, such as a living room, the system comprising said cold water generator, at least one thermal emitter and a hydraulic circuit for connecting the cold water generator to said at least one thermal emitter, said at least one thermal emitter comprising a ventilation means and a heat exchanger for a heat exchange between the water from the cold water generator and the air in the zone to be cooled, comprising the following steps:

[0006] - calculation of a dew point from a value of the air temperature in the area to be cooled and a relative humidity value of the air in the area, and

[0007] - calculation of a starting temperature, called optimal starting temperature, higher or equal to the calculated dew point.

[0008] Thus, thanks to the method according to the present invention, it is ensured that no condensate is formed, which avoids having to provide condensate drainage.

[0009] According to another aspect, there is provided a method in which the following calculation is used for the dew point _ M?» , with TR the dew point, T the value of aa(T, <p) the air temperature in the area, the relative humidity of the air in the area, and a(T. (p) — f— + liup, a ct b are two constants, 17 <a<18et 237<«<238.

[0010] According to another aspect, the following calculation is used for the dew point: Tr = (112 + 0.9T) + 0.1T - 112, with R the dew point, T the value of the air temperature in the area, and P the relative humidity of the air in the area.

[0011] According to another aspect, the optimal starting temperature, TDO, is equal to Tdo=Tr + c, where c is a constant between 0.5°C and 5°C, preferably 2°C.

[0012] According to another aspect, the value of the air temperature in the zone is obtained by a measurement of the air temperature either by a temperature sensor of said at least one thermal emitter, or of a temperature probe placed in said zone.

[0013] According to another aspect, the value of the humidity of the air in the area is obtained by a measurement of the relative humidity of the air by a relative humidity sensor of said at least one thermal transmitter and / or a remote station.

[0014] According to another aspect, when the air cooling system comprises a plurality of thermal emitters, the step of calculating the dew point is carried out for each thermal emitter, the method comprising a step of comparing the points of all the calculated dew points, the optimal starting temperature being calculated on the basis of the highest calculated dew point.

[0015] The invention also relates to a generator of cold water at a temperature, called the starting temperature, for a system for cooling air in a zone, such as a living room, the system comprising at least one thermal emitter comprising a ventilation means and a heat exchanger for a heat exchange between the water coming from the cold water generator and the air in the zone to be cooled, the generator being intended to be connected to said at least one thermal emitter, a hydraulic circuit, the generator comprising a calculation module for implementing the calculation method as described above.

[0016] The invention also relates to a thermal emitter for an air cooling system in an area, such as a living room, the thermal emitter being intended to be connected by a hydraulic circuit to a cold water generator at a temperature, called the flow temperature, of the cooling system, the thermal emitter comprising a ventilation means and a heat exchanger for a heat exchange between the water from the cold water generator and the air in the area to be cooled, the thermal emitter comprising a calculation module for implementing at least one of the steps of calculating a dew point and calculating a starting temperature, of the calculation method as described previously.

[0017] According to another aspect, the thermal emitter comprises a ventilation means and a heat exchanger for a heat exchange between the water from the cold water generator and the air of the area to be cooled.

[0018] The invention also relates to a system for cooling air in a zone, such as a living room, the system comprising a cold water generator at a temperature called the flow temperature, at least one thermal emitter and a hydraulic circuit for connecting the cold water generator to said at least one thermal emitter, the system comprising a module for calculating a dew point of the air in the zone to be cooled from a value of the air temperature in the zone and a value of relative humidity of the air in the zone, the system being configured to determine a flow temperature called optimal greater than or equal to the dew point temperature calculated by the calculation module.

[0019] According to another aspect, the calculation module uses the following formula to calculate the dew point _ ba(T^) with TÆthe dew point, T the value of the temperature of 1 R “ a-afT#) the air in the area, the relative humidity of the air in the area, and gîT^p) = + ln(p, a and b are two constants, 17 < « < 18 and 237 < a < 238.

[0020] According to another aspect, the calculation module uses the following formula to calculate the dew point: tk = ( 112 + 0.9T ) + 0.1T -112, with TR the dew point, T the value of the air temperature in the area, and P the relative humidity of the air in the area.

[0021] According to another aspect, the optimal starting temperature, TDO, is equal to Tdo - ?r + C, where c is a constant between 0.5°C and 5°C, preferably 2°C.

[0022] According to another aspect, said at least one thermal emitter comprises a temperature sensor and / or a relative humidity sensor, the module for calculating a dew point using as the air temperature value in the zone to be cooled the air temperature value measured by said temperature sensor and / or using as the relative humidity value the relative humidity value measured by said relative humidity sensor and / or a remote station.

[0023] According to another aspect, there is provided a computer program comprising instructions for implementing all or part of a method as defined herein when this program is executed by a processor. According to another aspect, there is provided a non-transitory, computer-readable recording medium on which such a program is recorded.

[0024] The invention also relates to a three-way valve for an air cooling system in an area, such as a living room, the system comprising a cold water generator at a temperature called the flow temperature, at least one thermal emitter and a hydraulic circuit for connecting the cold water generator to said at least one thermal emitter, the three-way valve being shaped to form part of said hydraulic circuit, the three-way valve comprising a calculation module for implementing the calculation method as described above.

[0025] Advantageously, this three-way valve is also capable of mixing the water supplied by the cold water generator and the water returned by said at least one thermal emitter to obtain an optimal water temperature. This implies that the conduits between the water generator and this three-way valve are protected against the appearance of condensate. Brief description of the drawings

[0026] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l

[0027] [Fig.l] shows a schematic view of a cooling system according to the present invention. Fig. 2

[0028] [Fig.2] shows a timing diagram of a method according to the present invention. Fig. 3

[0029] [Fig.3] shows a schematic view in longitudinal section of a fan coil according to the present invention. Description of the embodiments

[0030] The present disclosure relates to cooling an area, such as a room in a residential or commercial building, using a cooling system, referenced 1 in the figures. The system 1 ensures the implementation of a method 100 according to the present invention.

[0031] As visible in [Fig.l], the system 1 comprises a cold water generator 2. The cold water generator 2 is a heat pump, a chilled water unit or a geothermal source. The water temperature at the outlet of the generator 2 is called the water outlet temperature, noted TD. The system 1 also comprises at least one thermal emitter 3, such as a floor, a ceiling, a radiator, a hydraulic radiator or a fan coil, detailed later. The system 1 also comprises a hydraulic circuit 4 for connecting the generator 1 to each thermal emitter 3.

[0032] We will now describe in detail the method 100 for calculating the water outlet temperature TD of the generator 2, with reference to [Fig.2], to refresh the zone denoted Z.

[0033] As is apparent from this figure, the method 100 comprises a step (101, ROS) of determining a dew point TR from a value of the air temperature in the zone Z, denoted T, and a value of relative humidity of the air, P, in the zone Z.

[0034] The method 100 also comprises a step (102, DEP) of determining the water outlet temperature TD, strictly higher than the determined dew point.

[0035] Thus, at the end of the process 100, the water from the generator 2 circulates in the hydraulic circuit 4 at the temperature TD to supply water to the thermal emitter(s).

[0036] Preferably, during step 101, the following formula (I) is used for the dew point: j' _ WTjp), with Twlc dew point, T the value of the air temperature R aa[T, <p) in zone Z, (P the relative humidity of the air in the zone, and a( ç?) = + Inq)' a and b are two constants, 17 <a<18et 237<a<238.

[0037] Advantageously, the constant a = 17.27 and b = 237.7 °C.

[0038] The calculation based on formula (I) is valid for a temperature T between between 0°C and 60°C, a humidity level between 1% and 100%, and a dew point between 0°C and 50°C.

[0039] Formula (I) presents an approximation, the following formula (II), on the basis of which the calculation of step 101 can be made: TR = 4^ (112 + Q,9T ) + 0,1T - 112, with TR the dew point, T the value of the air temperature in the zone, and the relative humidity of the air in the zone.

[0040] During step 102, the following formula (III) is used to determine the starting temperature, considered to be optimal, TDO> equal to T do = TR + c, where c is a constant between 0.5°C and 5°C, preferably 2°C.

[0041] The constant c is a margin to take into account the hydraulic connections of the hydraulic circuit 4, which could also condense, and to compensate for rapid changes in the conditions (air temperature and / or humidity) in the room which could not be taken into account in view of the reaction inertia of the generator-transmitter pair.

[0042] It is noted that the value of the air temperature in the zone, T, is obtained by measuring the air temperature via a temperature sensor which may be located in the zone Z or be part of one or each of the thermal emitters.

[0043] It is also noted that the value of the air humidity in the zone, (P, is obtained by measuring the relative humidity of the air via a relative humidity sensor of one of the thermal emitters and / or a remote station.

[0044] Advantageously, the method comprises a step (103, MAX) of setting a maximum water outlet temperature, Tmax. The temperature Tmax corresponds to the point at which no generation of condensation is possible. This temperature is advantageously 18°C ​​but can be modified depending on the geographical area where the system 1 is used. Step 103 is carried out by pre-recording the value of the temperature Tmax or selected by a user.

[0045] Advantageously, the method comprises a step (104, MIN) of setting a minimum water outlet temperature, Tmin. The temperature Tmin corresponds to the dew point in the best climatic conditions. Advantageously, the temperature Tmin is equal to 7°C. Step 104 is carried out by pre-recording the value of the temperature Tmax or selected by a user.

[0046] Thus, the starting temperature TD is included in the temperature interval between the minimum temperature Tmin and the maximum temperature Tmax.

[0047] According to one embodiment of the invention, when the system 1 comprises a plurality of thermal emitters 3, the step 101 of calculating the dew point is carried out for each thermal emitter. The method 100 then comprises a step (105, COMP) of comparing all the calculated dew points. The starting temperature TD of step 102 is calculated on the basis of the highest calculated dew point.

[0048] The invention also relates to a computer program comprising instructions for implementing the method 100 when this program is executed by a processor.

[0049] The invention also relates to a non-transitory recording medium readable by a computer on which a program is recorded for implementing the method 100 when this program is executed by a processor.

[0050] The method 100 is implemented by a control unit UC (also called a calculation module) which can be fully included in the thermal emitter 3, or fully in the cold water generator 2, or partially in both, or even in a separate module (not shown), or partially in the thermal emitter 3, the cold water generator 2 and the separate module.

[0051] The thermal emitter 3 of [Fig.3] is now described.

[0052] As illustrated in this figure, the thermal emitter 3 is a fan coil unit. The fan coil unit 3 comprises a casing 10 provided with an air inlet 11 and an air outlet 12. The emitter 3 also comprises at least one fan 13 for forcing air into the casing 2 by convection. The emitter 3 also comprises a heat exchanger 14, for example of the hydraulic type, also called a cold battery. Advantageously, the emitter 3 contains a filter 15 behind the air inlet 11.

[0053] The heat exchanger 14 is preferably reversible. To heat the zone Z, it is the water flowing in the exchanger 14 which heats the air circulating in the emitter 3. Thus, the air sucked into the casing 10 through the air inlet 11 is heated in the exchanger 14, and heats the zone Z when it leaves the emitter 3 through the outlet 12.

[0054] To cool the zone Z, it is the air which transmits its calories to the water flowing in the exchanger 14. Thus, the air sucked into the casing 10 through the air inlet 11 is cooled in the exchanger 14, and cools the zone Z when it leaves the emitter 3 through the outlet 12.

[0055] As visible in [Fig. 3], the emitter 3 comprises a humidity sensor 16, preferably positioned near the inlet 11, in the air flow, at the bottom of the device. Alternatively, the humidity measurement is carried out by a remote station, in wired or wireless connection with the control unit UC. The transmitter is also equipped with a temperature probe 17 preferably placed on the inlet of the exchanger 14.

[0056] By remote station, we mean in particular the weather station closest to the premises comprising zone Z, the weather station closest to the transmitter in zone Z, a remote sensor in zone Z or even a sensor placed on the generator.

[0057] The transmitter 3 comprises a regulation control module 18 connected wired or wirelessly to the humidity and temperature sensors, so that the transmitter 3 can cooperate with the generator 2 of the heat pump type, for example, making it possible to produce heat and cold.

[0058] As seen in [Fig.3], the transmitter 3 is provided with a human-machine interface, 19, to allow a user to enter a target air temperature, in particular.

[0059] According to the alternative of [Fig. 3], the control unit UC is partially included in each transmitter 3, in the control module 18 for example, and in the generator 2. The communication between each thermal transmitter 3 and the generator 2 can be wired, or, preferably, wireless, by radio frequency, via the Zigbee protocol, for example. The UC-3 part of the control unit UC included in the transmitter 3 is connected, wired or wireless, to the humidity and temperature sensors and calculates the dew point of its transmitter 3. The UC-3 part communicates with the UC-2 part of the control unit UC included in the generator 2. The generator 2 then defines the starting temperature according to the starting temperatures calculated by each of the transmitters.

[0060] According to another alternative, not illustrated, the control unit is fully integrated into the generator 2. In this case, communication between each thermal emitter 3 and the generator 2 must be carried out so that the information necessary for the proper functioning of the system is transmitted. This communication can be carried out via different types of protocols and different physical means. The communication between each thermal emitter 3 and the generator 2 can be wired, or, preferably, wireless, by radio frequency, via the Zigbee protocol, for example. The generator 2 centralizes humidity and temperature measurements and the control unit calculates the dew point, then the water outlet temperature.

[0061] According to another alternative, not illustrated, the control unit is part of an ambient control, which controls the group of transmitters 3. In this case, the implementation of the method 100 takes place at the level of the ambient control, which collects the humidity measurements or measures the humidity itself, carries out the calculations and ensures a link between the transmitters 3 and the generator 2.

[0062] In another embodiment, not illustrated, the system 1 also comprises a three-way valve between the generator 2 and the emitter(s). In this case, the generator has a fixed, very low water temperature (from 12°C to 16°C for example). It is the three-way valve which centralizes the information on the dew points of the emitters, to calculate an optimal water temperature, then mixes the water from the return circuit with the water coming from the generator to adjust the water outlet temperature to a value such that there is no appearance of condensate, according to the implementation of the method 100. Thus, according to this embodiment, the water outlet temperature, denoted Td, is the mixing temperature of the temperature at the outlet of the generator 2 and the temperature of the water coming from the return circuit.

[0063] In another embodiment, not illustrated, the thermal emitter 3 is a hydraulic radiator, for example made of steel, equipped with a digitally controlled thermostatic head. The temperature and humidity measurements are preferably carried out in the thermostatic head. The generator 2 is a heat pump capable of producing heat and cold. Communication between the emitter and the generator is carried out by radio frequency using the Zigbee protocol or other. The calculations of the dew points and water temperature are carried out by each emitter. The generator defines the flow temperature according to the flow temperatures calculated by each of the emitters.

[0064] Of course, the invention is not limited to these embodiments; the invention encompasses any combination of thermal emitter of the floor, ground, ceiling, wall, fan coil, hydraulic radiator type, with a generator of the heat pump type, chilled water unit, geothermal source ensuring the implementation of the method 100.

[0065] For each embodiment, the calculation of the dew point ensures optimal determination of the water outlet temperature of the water generator, avoiding any formation of condensate on the emitters 3, which avoids having to look for means of evacuating the condensate.

[0066] The method according to the present invention also makes it possible not to thermally insulate the hydraulic circuit from humidity, which avoids having to resort to thermal insulation of the hydraulic connections.

[0067] The method according to the present invention also makes it possible to generate more cold heating power, if the humidity level allows it, compared to a prior art system which will be limited to 16°C permanently.

[0068] It is noted that the system 1 provides direct or indirect air cooling. In particular, the ceiling or floor type emitters exchange energy via radiation towards the surfaces and objects of the zone Z which themselves, by contact with the air, cool it.

[0069] It is also noted that the system 1 is not necessarily exclusively intended for cooling the zone Z. The system 1 may be of the type to provide cooling, and / or ventilation and / or heating.

Claims

Claims

1. Method for calculating a water outlet temperature of a cold water generator, for an air cooling system of a zone, such as a living room, the system (1) comprising said cold water generator (2), at least one thermal emitter (3) and a hydraulic circuit (4) for connecting the cold water generator (2) to said at least one thermal emitter (3), the method (100) comprising the following steps: - calculating a dew point from a value of the air temperature in the zone to be cooled and a value of relative humidity of the air in the zone, and - calculating a outlet temperature, called optimal outlet temperature, greater than or equal to the calculated dew point.

2. A method according to claim 1, wherein the following calculation is used for the dew point _ ba(Tjp), with TK the dew point, T the a-aÇTjp) value of the air temperature in the area, the relative humidity of the air in the area, and a(T, (p) = + Irup, a and b are two constants, 17 <a<18et 237<<7<238.

3. A method according to claim 1, wherein the following calculation is used for the dew point: = 112 + 0.97) +0.1T- 112, with TK the dew point, T the value of the air temperature in the area, and the relative humidity of the air in the area.

4. Method according to one of the preceding claims, in which the optimal starting temperature, T DO, is equal to T do — Tr + c, where c is a constant between 0.5°C and 5°C, preferably 2°C.

5. Method according to one of the preceding claims, in which the value of the air temperature in the zone is obtained by a measurement of the air temperature either by a temperature sensor of said at least one thermal emitter, or of a temperature probe placed in said zone.

6. Method according to one of the preceding claims, wherein the value of the humidity of the air in the area is obtained by a measurement of the relative humidity of the air by a relative humidity sensor of said at least one thermal transmitter and / or a remote station.

7. A method according to any preceding claim, wherein, when the air cooling system comprises a plurality of emitters thermal emitters, the step of calculating the dew point is carried out for each thermal emitter, the method comprising a step of comparing the points of all the calculated dew points, the optimal flow temperature being calculated on the basis of the highest calculated dew point.

8. Cold water generator at a temperature, called the starting temperature, for an air cooling system for an area, such as a living room, the system comprising at least one thermal emitter (3) comprising a ventilation means (13) and a heat exchanger (14) for a heat exchange between the water from the cold water generator and the air of the area to be cooled, the generator (2) being intended to be connected to said at least one thermal emitter (3) a hydraulic circuit (4), the generator (2) comprising a calculation module for implementing the calculation method according to one of claims 1 to 7.

9. Thermal emitter for an air cooling system of an area, such as a living room, the thermal emitter (3) being intended to be connected by a hydraulic circuit (4) to a cold water generator (2) at a temperature, called the flow temperature, of the cooling system, the thermal emitter comprising a ventilation means (13) and a heat exchanger (14) for a heat exchange between the water coming from the cold water generator and the air of the area to be cooled, the thermal emitter comprising a calculation module for implementing at least one of the steps of calculating a dew point and calculating a flow temperature, of the calculation method according to one of claims 1 to 7.

10. Thermal emitter according to the preceding claim, comprising a ventilation means (13) and a heat exchanger (14) for a heat exchange between the water coming from the cold water generator and the air of the area to be cooled.

11. System for cooling air in an area, such as a living room, the system comprising a cold water generator (2) at a temperature called the flow temperature, at least one thermal emitter (3) and a hydraulic circuit for connecting the cold water generator to said at least one thermal emitter, the system comprising a module for calculating a dew point of the air in the area to be cooled from a value of the temperature of the air in the area and a value of relative humidity of the air in the area, the system being configured to determine a flow temperature called the optimal flow temperature greater than or equal to the dew point temperature calculated by the calculation module.

12. System according to the preceding claim, in which the calculation module uses the following formula to calculate the dew point: T _ , with TR the dew point, T the value of the temperature of R aa(T^>) the air in the zone, 9 the relative humidity of the air in the zone, and a( T, (p) = 4- Inqh a and b are two constants, 17 < a < 18 and 237<«<238.

13. The system of claim 11, wherein the calculation module uses the following formula to calculate the dew point: Tr = 112 + 0.97) + 0.17- 112, with TR the dew point, T the value of the air temperature in the area, and (P the relative humidity of the air in the area.

14. System according to one of claims 11 to 13, in which the optimal starting temperature, T DO, is equal to T do — T r + c, where c is a constant between 0.5°C and 5°C, preferably 2°C.

15. System according to the preceding claim, in which said at least one thermal transmitter comprises a temperature sensor and / or a relative humidity sensor, the module for calculating a dew point using as the value of the air temperature in the zone to be cooled the air temperature value measured by said temperature sensor and / or using as the relative humidity value the relative humidity value measured by said relative humidity sensor and / or a remote station.

16. Computer program comprising instructions for implementing the method according to one of claims 1 to 7 when this program is executed by a processor.

17. Non-transitory recording medium readable by a computer on which is recorded a program for implementing the method according to one of claims 1 to 7 when this program is executed by a processor.

18. Three-way valve for an air cooling system for an area, such as a living room, the system comprising a cold water generator (2) at a temperature called the flow temperature, at least one thermal emitter (3) and a hydraulic circuit for connecting the cold water generator to said at least one thermal emitter, the valve three-way valve being shaped to form part of said hydraulic circuit, the three-way valve comprising a calculation module for implementing the calculation method according to one of claims 1 to 7.

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