WO2017198960A1

WO2017198960A1 - Datacentre comprising a rack of servers and a cooling system and method for cooling such a datacentre

Info

Publication number: WO2017198960A1
Application number: PCT/FR2017/051216
Authority: WO
Inventors: Jérôme GREMAUD; Anne Laure GREMAUD; Claude DOS SANTOS; Antony MORET
Original assignee: Jerlaure
Priority date: 2016-05-18
Filing date: 2017-05-18
Publication date: 2017-11-23
Also published as: FR3051571B1; FR3051571A1

Abstract

The datacentre (10) comprises servers (110), a cooling system (105) and a thermometer (185). The cooling system comprises: – a cold-producing device (135) comprising a reagent and a fluid producing a reversible thermochemical reaction, the vaporizing of the fluid absorbing heat, – an air cooling device (125) comprising a heat exchanger exchanging heat between the outside (130) and the inside (120). A controller (190) controlling the cooling system such that, when the external temperature is: – below a first value (170), the cooling device is activated without evaporation, – comprised between the first value and a second value (175), the cooling device is activated with evaporation, – above the second value, the producing device and the cooling device are activated.

Description

DATA CENTER COMPRISING A SERVER BAY AND A COOLING SYSTEM AND METHOD FOR COOLING SUCH A CENTER OF

DATA

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a data center comprising a server rack and a cooling system and a method of cooling such a data center. It applies, in particular, to computer data centers located in regions where the air temperature can reach more than 26 ° C in summer.

STATE OF THE ART

Data Centers ("Data Centers") are places where computer information management or data management equipment is required for the activities of a business. The operation of computer equipment produces significant heat releases. If the temperature inside a data center becomes too high, equipment availability is no longer assured and failures can occur.

The energy efficiency indicator ("Power Usage Effectiveness") is a ratio between the total energy consumed by the data center and the energy consumed by the computer equipment. For older data centers, the energy efficiency indicator is greater than or equal to two.

Currently, the data centers are preferably located in regions where the outside temperature is below 25 ° C throughout the year. The energy consumption for the cooling of the servers is thus reduced by the use of ventilation with outside air.

A problem with the use of this technique is a high water consumption to operate the cooling systems.

Other data centers include a heat pump to cool servers in unusually high temperatures. However, the energy efficiency indicator is then higher, for example between 1, 5 and 1, 8.

OBJECT OF THE INVENTION

The present invention aims to remedy all or part of these disadvantages. In particular, the present invention aims at a data center for which the energy efficiency indicator is less than 1.15. For this purpose, according to a first aspect, the present invention is directed to a data center comprising at least one server bay and a cooling system of each server bay which comprises:

at least one external temperature sensor sensing a temperature external to the data center,

wherein the cooling system comprises:

at least one cold production device comprising a reactive medium in a reactor, a reservoir comprising a fluid and means for circulating the fluid between the reservoir and the reactor, the fluid and the reactive medium producing a reversible thermochemical reaction by means of a feed of energy, the vaporization of the fluid between the reservoir and the heat-absorbing reactor,

at least one air cooling device which comprises an evaporative heat exchanger between the external air of the environment of the data center and the air inside the data center,

at least one control automaton of the cooling system as a function of the external temperature, and a representative variable dependent on a state of the thermochemical reaction of the cold production device:

in a first mode of operation when the external temperature is lower than a first predetermined limit value, in which the air cooling device is activated without evaporation,

in a second mode of operation when the external temperature is between the first predetermined limit value and a second predetermined limit value, and depending on the variable, in which the air cooling device is activated with evaporation,

in a third mode of operation when the external temperature is greater than the second predetermined limit value, and / or depending on the variable, in which the cold generating device and the air cooling device are activated.

Thanks to these provisions, the cooling system allows different cooling depending on the temperature outside the data center. In addition, each element of the cooling system is highly energy efficient.

In particular, the cold generating device uses a thermal energy, for example, to reverse the thermochemical reaction and, by vaporization of the fluid, absorbs heat. Thus, a heat source at high temperature makes it possible to minimize the energy consumption of the cooling system. In addition, depending on the state of the thermochemical reaction of the cold producing device, the cold generating device can be operated to limit the water consumption of the air cooling device.

In embodiments, the object data center of the present invention includes an internal temperature sensor at the data center and wherein the controller controls the cooling system according to the third mode of operation when the internal temperature is higher. at a third predetermined limit value during a first predetermined duration.

These embodiments make it possible to take into account the passive cooling of the building for triggering the cooling system. As a reminder, the passive cooling of a building is any installation during the construction of the building that does not consume energy to cool the building. Indeed, the modes of operation of the cooling system are activated preventively depending on the indoor temperature and a duration.

In embodiments, once the cooling system is controlled according to the third mode of operation, the controller controls the cooling system according to the first mode of operation or the second mode of operation if the internal temperature is lower. at the third predetermined limit value.

The advantage of these embodiments is to avoid unnecessarily turning off the cold generating device if the internal temperature is above the third predetermined limit value.

In embodiments, the cooling system includes a cold energy storage tank having water, the storage of cooling energy being effected by changing the phase of the water from a liquid phase to a solid phase. , the cooling energy being stored when the cooling system is controlled according to the first operating mode, the cooling energy being consumed when the cooling system is controlled according to the second and / or the third mode of operation.

These embodiments make it possible to store surplus cooling energy production in order to release it during a subsequent request. In particular, in the case of a strong external momentary heat.

In embodiments, the data center object of the present invention comprises at least one solar panel or at least one source of fatal thermal energy producing thermal energy supplying the cooling device with energy to reverse the reaction. thermochemical. The advantage of these embodiments is to limit the electrical energy from the national power grid consumed by the data center. The energy produced by each solar panel can reverse the thermochemical reaction of the reactor and produce cold when the fluid vaporizes. Thus, the energy efficiency indicator is improved since the data center produces some of the energy needed to cool each server bay.

In embodiments, the object data center of the present invention includes means for capturing the mass enthalpy of the outside air near the data center, when the mass enthalpy is greater than a first predetermined limit value. of mass enthalpy, the cold generating system is activated in the third mode until the external mass enthalpy is less than a second predetermined limit value of mass enthalpy for a second predetermined duration.

The advantage of these embodiments is to take into account the humidity of the outside air to determine the supply of cooling energy needed for the interior of the data center.

In embodiments, the data center object of the present invention comprises a meteorological data capture device, at least one limit value being modified according to the meteorological data captured.

These embodiments make it possible to adapt the limit values for which each mode of operation of the cooling system is activated. In particular, depending on the outdoor hygrometry captured.

According to a second aspect, the present invention is directed to a method of cooling a data center comprising at least one server bay and a cooling system comprising:

which has the following steps:

- capture of a temperature external to the data center, determination of a representative variable dependent on a state of the thermochemical reaction of the cooling device,

- control of the cooling system:

in a second mode of operation when the external temperature is between the first predetermined limit value and a second predetermined limit value, and depending on the variable, in which an air cooling device is activated with evaporation,

in a third mode of operation when the external temperature is greater than the second predetermined limit value, and / or depending on the variable in which a cold generating device and the air cooling device are activated.

Since the aims, advantages and particular features of the method which are the subject of the present invention being similar to those of the data center that is the subject of the present invention, they are not recalled here.

BRIEF DESCRIPTION OF THE FIGURES

Other advantages, aims and particular characteristics of the invention will emerge from the following nonlimiting description of at least one particular embodiment of the data center and the cooling method that are the subject of the present invention, with reference to the attached drawings. , wherein :

FIG. 1 represents, schematically, a first particular embodiment of the data center that is the subject of the present invention,

FIG. 2 represents, schematically and in graph form, the activation mode of the cooling system of the data center that is the subject of the present invention, and

FIG. 3 represents, schematically and in logic diagram form, a first particular embodiment of the method that is the subject of the present invention.

DESCRIPTION OF EXAMPLES OF EMBODIMENT OF THE INVENTION

This description is given in a nonlimiting manner, each feature of an embodiment being able to be combined with any other feature of any other embodiment in an advantageous manner. Moreover, each parameter of an example of embodiment can be implemented independently of other parameters of said exemplary embodiment.

It is already noted that the figures are not to scale.

FIG. 1, which is not to scale, shows a schematic view of an embodiment of the data center 10 object of the present invention.

The data center 10 comprises a building 100. The building 100 houses at least one server bay 1 10 and a cooling system 105 of each server rack 1 10. The building 100 is configured to optimize the passive cooling of each bay of servers. It is recalled here that passive cooling is any installation that consumes no energy to cool air. Preferably, the air flow flows between each server rack 1 10, when the external temperature is lower than a first predetermined limit value 170 are optimized. Preferably, the thermal inertia of the building 100 is optimized. In particular the architecture and the exposure of the building 100 limit the contributions in thermal energy.

The cooling system 105 comprises at least one cold-generating device 135 comprising a reactive medium in a reactor 145, a reservoir comprising a fluid and means for circulating the fluid 140 between the reservoir and the reactor 145. The fluid and the medium The reagent produces a reversible thermochemical reaction by supply of energy, the vaporization of the fluid between the reservoir and the reactor 145 absorbs heat.

Preferably, the fluid is ammonia. The fluid reacts with the reactive medium in the reactor 145, the reaction is then exothermic. Once the thermochemical reaction is complete, the reactor 145 is supplied with energy to reverse the thermochemical reaction and separate the fluid from the reactive medium. With the addition of energy, the fluid in gaseous form is expelled to a condenser. Then the fluid is stored in a reservoir in liquid form. The vaporization of the fluid in at least one vaporizer 140 of the cold producing device 135 produces heat absorption. In the vaporizer 140 the fluid changes from the liquid state to the gaseous state. The fluid is then injected into the reactor 145 to reproduce the cycle described above.

Preferably, the cooling system 105 comprises at least five cold generating devices 135.

Preferably, the energy input of the reactor 145 is a thermal energy input. The weather conditions outside the data center 10 can be exploited to provide the thermochemical reaction to cool the building 100.

In embodiments, the data center 10 has at least one solar panel 215 or at least one fatal thermal energy source 220 producing thermal energy. It is recalled here that the fatal energy is an ineluctably energy present or trapped in certain processes or products. The source of fatal thermal energy may come from an industrial process, a dump, the exhaust gases of an electricity generating group (gas or diesel) or any other device from the moment the following conditions of use are met. The temperature of the fatal heat source 220 is between 150 ° C and 200 ° C. The power available at the output of the fatal heat source is between two and three times the power of the reactor 145.

The thermal energy supplies the reactor 145 of the cold producing device 135 with energy to reverse the thermochemical reaction. With these embodiments, the electrical power consumption of the cooling system 105 is decreased and the energy efficiency indicator of the data center 10 is improved.

Each solar panel 215 concentrates the solar radiation captured on at least one tube comprising a heat transfer fluid. Preferably, the coolant is water under pressure. The heat transfer fluid is conveyed to the reactor 145 by the activation of a pump.

In preferred embodiments, each solar panel 215 is a parabolic solar panel with reflective glass. These embodiments make it possible to increase the quantity of energy transmitted to the coolant. Preferably, each solar panel 215 is disposed on a roof of the building 100 of the data center 10. Preferably, each solar panel 215 comprises at least one solar ray incidence sensor and a movable support configured to orient the solar panel 215 as a function of the incidence of solar rays captured. The mobile support is configured to arrange each solar panel 215 in a so-called safety position limiting the risk of damage to each solar panel 215 during inclement weather.

The cooling system 105 also comprises at least one air-cooling device 125 which includes an evaporative heat exchanger between the outside air 130 in the environment of the data center 10 and the inside air 120 at the data center 10. The air cooling device 125 is commonly called "free cooling" in English, literally "free cooling" in French. Preferably, the air cooling device comprises an air handling unit (acronym "CTA").

The outside air 130 in the environment of the data center 10 is humidified in the air cooler 125 which has at least one air humidifier. The heat energy contained in the indoor air 120 at the data center 10 is transmitted by heat exchange to the outside air and humidified 130. The indoor air 120 is thus cooled. The cooling system 105 comprises at least one control automat 190 of the cooling system 105.

The data center 10 comprises at least one external temperature sensor 155 sensing a temperature external to the data center 10. The sensed external temperature is transmitted to the control automaton 190. A command, 200, 205 or 210, issued from the The controller 190 is dependent on the sensed external temperature.

The cold generating device 135 communicates to the controller 190 a representative variable 225 depending on a state of the thermochemical reaction of the air cooling device. The variable 225 can be a binary variable of which:

a state represents the absorption of heat during the vaporization of the fluid, and therefore the production of cold by the cold producing device 135, a so-called "cold generating capacity" condition and

- the other state represents the absence of a thermochemical reaction, a state called "inability to produce cold".

The cooling system 105 is controlled according to a first operating mode A when the external temperature is lower than a first predetermined limit value 170, in which the air-cooling device 125 is activated without evaporation of water. Preferably, the first predetermined limit value 170 is equal to eighteen degrees Celsius (18 ° C). In the first operating mode A of the cooling system 105, the passive cooling of the building 100 is implemented to cool each server rack 1 10 and the air cooling device is activated without evaporation of water.

The cooling system 105 is controlled according to a second operating mode B when the external temperature is between the first predetermined limit value 170 and a second predetermined limit value 175, and if the refrigerating device 135 is in a state of operation. inability to produce cold, wherein the air-cooling device 125 is activated with evaporation of water. Preferably, the second predetermined limit value 175 is strictly greater than the first predetermined limit value. Preferably, the second predetermined limit value 175 is equal to twenty-six degrees Celsius (26 ° C). In the second operating mode B of control of the cooling system 105, the passive cooling of the building 100 is implemented as well as the cooling by heat exchange with evaporation of water of the air-cooling device 125.

The cooling system 105 is controlled according to a third operating mode C when the external temperature is greater than the second predetermined limit value 175, and / or if the cold-generating device 135 is in a state of operation. ability to produce cold, wherein the cold producing device 135 and the air cooling device 125 are activated.

Preferably, once the cooling system 105 is controlled according to the third mode of operation C and the external temperature is lower than the second predetermined limit value 175, the controller 190 controls the cooling system according to the first mode of operation. operation A or the second operating mode B if the internal temperature is lower than a third predetermined limit value 180.

In preferred embodiments, the controller 190 controls the cooling system 105 according to the third mode of operation C when the internal temperature 185 is greater than the third predetermined limit value called "set value" 180 during a first duration. predetermined. These embodiments make it possible to momentarily use the cold generating device 135 when the air cooling device 125 is insufficient for the internal temperature to reach the set value while the second predetermined limit value 175 is not exceeded. Preferably, the first predetermined duration is equal to ten minutes.

In embodiments, the cooling system 105 includes a refrigerating energy storage tank 230 including water, the refrigeration energy storage being effected by changing the phase of the water from a liquid phase to a liquid phase. solid phase. The cooling energy is stored when the cooling system 105 is controlled according to the first operating mode A, the cooling energy being consumed when the cooling system 105 is controlled according to the second operating mode B and / or the third operating mode. functioning C.

The cooling energy storage tank 230 is a reservoir comprising water, whose water is converted into ice by thermal absorption. The cold producing device 135 absorbs the cooling energy of water and ice contained in the refrigerating energy storage tank 230 during the vaporization of the fluid in the cold production device 135.

The mass enthalpy of the outdoor air depends on the outside air temperature and the hygrometry of the outside air. The higher the mass enthalpy of the outside air, the lower the capacity of the air cooler 125 is reduced.

In embodiments, the data center 10 includes means for capturing the mass enthalpy of the outside air 160 near the data center 10, when the mass enthalpy is greater than a first predetermined limit value of mass enthalpy, the cold producing device 135 is activated until the external mass enthalpy is less than a second predetermined limit value of mass enthalpy for a second predetermined duration. The means for capturing the mass enthalpy of the outside air 160 comprises a hygrometric sensor. The means for capturing the mass enthalpy of the outside air 160 calculates the mass enthalpy of the outside air by means of the external temperature sensed and the hygrometry captured.

Preferably, the first predetermined limit value of mass enthalpy is equal to 60 kJ / kg AS (kilojoules per kilogram of dry air) and the second predetermined limit value of specific enthalpy is equal to 50 kJ / kg AS. It is recalled here that the mass enthalpy of dry air at zero degrees is, by convention, 0 kJ / kgAS. Preferably, the second predetermined duration is sixty minutes.

In embodiments, the data center 10 includes a meteorological data capture device 165, at least one limit value, 170, 175, 180, the first predetermined limit value of enthalpy, the second predetermined limit value of enthalpy. , the first predetermined duration and / or the second predetermined duration being modified according to the meteorological data captured. The controller 190 comprises means 195 for adapting at least one predetermined value according to the meteorological data received. The adaptation means 195 is a microprocessor, for example.

The meteorological data captured by the meteorological data capturing device 165 are temperature, hygrometry, wind speed and direction to control the orientation and folding of the solar panels. The external temperature sensor 155 and the means for capturing the mass enthalpy of the outside air 160 may be integrated with the meteorological data capture device 165.

In embodiments, at least one predetermined limit value is changed according to user preferences.

In FIG. 1, the control automat 190 collects the following data:

the representative variable 225 dependent on a state of the thermochemical reaction of the cold production device

an internal temperature,

an external temperature,

- a mass enthalpy of the outside air and

- meteorological data.

The following limit values are stored in a memory of the PLC 190:

the first predetermined limit value 170,

the second predetermined limit value 175, the third predetermined limit value 180 or set value,

the first limit value of enthalpy,

the second limit value of enthalpy,

the first predetermined duration and / or

the second predetermined duration.

Depending on the data collected, the controller 190 sends a set 200 for starting or stopping an evaporation device of the air-cooling device 125. The control automat 190 sends a setpoint 205 of storage or consumption of the cooling energy by the refrigerating energy storage tank 230. The control automat 190 sends a set-point 210 for starting or stopping the cold-generating device 135, if the cooling device air cooling 125 is already in operation and / or if the variable 225 represents a state of ability to produce cold.

The operation of the cold generating device 135 is called the vaporization of the fluid.

The cold from the vaporizer 140 of the cold producing device 135 can be injected directly into an ice water network at the outlet of the cooling system 1 or the cold can be stored in the cold energy storage tank 230 and injected. subsequently in the chilled water network 1 15 at the outlet of the cooling system 105.

Preferably, the air inside the data center 10 is sucked by at least one aeration mouth connected to a ventilation duct directing the air flow 120 at the inlet of the air-cooling device 125. The ventilation duct 120 is preferably parallel to a duct of the chilled water network 1 15 at the outlet of the cooling system 105. Preferably, each server rack 1 10 is disposed perpendicular to the air flow 120 defined by a ventilation duct.

When the cooling system 105 is controlled according to the second operating mode B, the air flow 120 comes from a building room 100 comprising at least one server rack 1 10 and is sucked up to the air cooling device 125. A heat exchange takes place in the air-cooling device 125 with an outside air flow 130 at the data center 10. Preferably, the flows of internal air 120 and of outside air 130 are oriented in opposite directions. .

When the cooling system 105 is controlled according to the third mode of operation C, the airflow 120 comes from a building room 100 having at least one server bay 1 10 and is sucked up to the air cooling device 125. A heat exchange takes place in the air-cooling device 125 with a flow of air outside the data center 130. Preferably, the flows are oriented in opposite directions. A heat exchange then takes place between the chilled water network 1 15 at the outlet of the vaporizer 140 of the cold-generating device 135 which absorbs the heat of the flow 120 at the outlet of the air-cooling device 125.

In embodiments in which refrigeration energy has previously been stored in the storage tank 230, at least a portion of the chilled water network 1 15 at the outlet of the air-cooling device 125 is cooled by heat exchange with the water contained in the storage tank 230 before or after having been cooled by the cold-producing device 135.

FIG. 2 shows a schematic diagram showing the operating mode of the cooling system 105 of the data center 10 by the control automaton 190 as a function of time.

The abscissa 25 represents the time on a day comprising twenty-four hours. The ordinate 24 represents, with respect to the curves 21, 22, 26, 27, and 28 a temperature in degrees Celsius and as regards the curves 23, 29 and 30, a mass enthalpy in kJ / kgAS.

Curve 21 represents the internal temperature sensed. Curve 22 represents the sensed external temperature. Curve 23 represents the mass enthalpy of the captured outside air. Curve 26 represents the first predetermined limit value. Curve 27 represents the second predetermined limit value. Curve 28 represents the set point between curve 26 and curve 27. Curve 29 represents the first predetermined value of enthalpy. Curve 30 represents the second predetermined value of enthalpy that is less than curve 29. Curves 26, 27, 28, 29 and 30 are straight lines.

The interval 31 on the abscissa 25 represents the first predetermined duration. The interval 32 on the abscissa 25 represents the second predetermined duration. The graph is separated vertically by lines corresponding to events likely to change the operating mode of the cooling system 105 of the data center 10.

In the first section, the curve representative of the external temperature 21 is lower than the first predetermined limit value 26. And the curve representative of the mass enthalpy of the outside air 23 is lower than the first predetermined limit value of enthalpy 29 The cooling system 105 is controlled according to the first operating mode A. In the second section, the curve representative of the external temperature 21 is greater than the first predetermined limit value 26 and less than the second predetermined limit value 27. And the representative curve of the mass enthalpy of the outside air 23 is less than the first predetermined limit value of enthalpy 29. It is considered that the variable 225 represents a state of inability to produce cold. The cooling system 105 is controlled according to the second operating mode B.

In the third section, the curve representative of the internal temperature 21 is greater than the set value 28 and lower than the second predetermined limit value 175. And the curve representative of the mass enthalpy of the outside air 23 is less than the first predetermined limit value of enthalpy 29. It is considered that variable 225 represents a state of inability to produce cold. The cooling system 105 is controlled according to the second operating mode B and a timer equal to the first predetermined duration 31 is started.

With regard to the second and third sections, if variable 225 were considered to represent a state of ability to produce cold, the cold production system would be controlled according to the third mode of operation C.

In the fourth section, the curve representative of the internal temperature 21 is greater than the set point 28 and lower than the second predetermined limit value 175 since the beginning of the first predetermined duration 31 which has elapsed. And the representative curve of the mass enthalpy of the outside air 23 is lower than the first predetermined limit value of enthalpy 29. The cooling system 105 is controlled according to the third mode of operation C.

In the fifth section, the curve representative of the internal temperature 21 is lower than the second reference value 28. And the curve representative of the mass enthalpy of the outside air 23 is less than the first predetermined limit value of enthalpy 29 but the variable 225 represents a cold generating capacity state of the cold producing device 135. The cooling system 105 is controlled according to the third mode of operation C.

If the variable 225 represented a state of inability to produce cold the cooling system 105 would be controlled according to the second mode of operation B

In the sixth section, the curve representative of the external temperature 22 is greater than the second predetermined limit value 27. And the curve representative of the mass enthalpy of the outside air 23 is lower than the first predetermined limit value of enthalpy 29 And variable 225 represents a cold generating capacity state of the cold producing device 135. The cooling system 105 is controlled according to the third mode of operation C. In the seventh section, the curve representative of the external temperature 22 is smaller than the second predetermined limit value 27 and the curve representative of the internal temperature is greater than the reference value 28. And the curve representative of the mass enthalpy of the Outside air 23 is less than the first predetermined limit value of enthalpy 29. And variable 225 represents a state of cold generating capacity of cold generating device 135. Cooling system 105 is controlled according to the third mode of cooling. functioning C.

In the eighth section, the curve representative of the external temperature 22 is smaller than the second predetermined limit value 27 and the curve representative of the internal temperature is less than the set value 28. And the curve representative of the mass enthalpy of the Outside air 23 is less than the first predetermined limit value of enthalpy 29. Cooling system 105 is controlled according to second operating mode B.

In the ninth section, the curve representative of the external temperature 22 is greater than the first predetermined limit value 26 and lower than the second predetermined limit value 27. And the representative curve of the mass enthalpy of the outside air 23 is greater than the first predetermined limit value of enthalpy 29. And the variable 225 represents a state of cold generating capacity of the cold producing device 135. The cooling system 105 is controlled according to the third mode of operation C.

In the tenth section, the curve representative of the external temperature 22 is lower than the first predetermined limit value 26. And the curve representative of the mass enthalpy of the outside air 23 is lower than the second predetermined limit value of enthalpy 30 and a timer equal to the second predetermined duration 32 is started. And the variable 225 represents a cold generating capacity state of the cold producing device 135. The cooling system 105 is controlled according to the third mode of operation C.

In the eleventh and last section, the curve representative of the external temperature 22 is lower than the first predetermined limit value 26. And the curve representative of the mass enthalpy of the outside air 23 has remained lower than the second predetermined limit value d enthalpy 30 for the second predetermined duration 32 which has elapsed. The cooling system 105 is controlled according to the first operating mode A. FIG. 3 shows a schematic flow diagram of a cooling method 300 of a data center 10 comprising at least one server rack 1 10 and a cooling system 105 as described with reference to FIG. above.

The cooling method 300 comprises at least one capture step for each transition 302, 304, 313, of a temperature external to the data center 10. The external temperature at the data center 10 is continuously sensed by the external temperature sensor 155. The controller 190 compares the external temperature with the setpoint plus one.

The cooling method 300 comprises a step 301, 303, 309 for controlling the cooling system 105.

The cooling method 300 comprises a control step 301 of the cooling system 105 according to a first operating mode A when the external temperature is lower than a first predetermined limit value 170, in which the air cooling device is activated without evaporation of 'water.

The cooling method 300 includes a control step 303 in a second operating mode B when the external temperature is between the first predetermined limit value 170 and the second predetermined value 175, in which an air cooling device 125 is activated.

The cooling method 300 comprises a control step 309 according to a third operating mode C when the external temperature is higher than the second predetermined limit value, in which a cold-generating device 135 and the air-cooling device 125 are activated. .

As long as the control of the cooling system 105 is not modified by the cooling method 300, the cooling system 105 continues to be controlled according to the operating mode A, B or C previously active.

When the external temperature is below the first predetermined limit value 170, the step 301 of operating the cooling system 105 according to the first operating mode A is active. The external temperature is continuously sensed and compared with the first predetermined limit value 170 and the second predetermined limit value 175. The transition 302 has an associated comparison condition, if the external temperature is greater than the predetermined limit value 170 then the process Cooling 300 passes:

in step 303 for putting the cooling system 105 into operation according to the second operating mode B if the variable 225 represents a state of inability to produce cold, and in step 309 for putting the cooling system 105 into operation according to the third mode of operation C if the variable 225 represents a state of capacity to produce cold

Otherwise the control step 301 of the cooling system 105 according to the first operating mode A is active.

During transition 304 following step 303, if the external temperature is greater than the second predetermined limit value 175, the method proceeds to step 309 of controlling the cooling system according to the third mode of operation C.

At the same time, during the transition 305, if the internal temperature is higher than the set value 180, the process proceeds to the timer transition 306 by a first predetermined duration. If during the time of the delay and at the end of the delay, the transition criterion 307 is satisfied, ie if the internal temperature is greater than the set value 180, the control step 309 of the system according to the third mode of operation C is activated.

Otherwise the control step 303 of the cooling system 105 according to the second operating mode B is activated.

Each transition 304, 305, and 307 are tested on a regular basis.

In preferred embodiments, a transition 314 following the control step 303 whose condition is to determine whether the enthalpy of the outside air is greater than the first predetermined limit value of enthalpy is tested in parallel with the group comprising the transitions 304, 305, 306 and 307. If the condition of the transition 314 is satisfied, the transitions 304, 305, 306 and 307 are not verified, the control step 309 of the cooling system 105 according to the third mode of C operation is directly activated. Otherwise, the control step 303 of the cooling system 125 according to the second operating mode B continues to be implemented and the transitions 304 and 305 continue to be tested.

As soon as the control step 309 of the cooling system 105 according to the third operating mode C is activated and as long as the external temperature is greater than the second predetermined limit value 175, the control step 309 continues to be put into operation. artwork.

A transition 316 whose condition is to determine if the internal temperature is lower than the third predetermined value is implemented. If this transition is enabled, the process proceeds to transition 310. Otherwise, the process returns to step 303 of controlling the cooling system according to the second mode. A transition 313 whose condition is to determine if the external temperature is lower than the setpoint is implemented. If this transition is enabled, the cooling system is controlled according to step 301 or step 303.

In preferred embodiments, before the transition 313, a transition 310 whose condition is to test whether the enthalpy of the outside air is less than a second predetermined limit value of enthalpy is implemented. If the transition is verified, a timing step 31 1 of a second predetermined duration is implemented. Otherwise the control step 309 according to the third mode of operation C continues to be implemented. Once the delay of step 31 1 has been completed, a transition 312 whose condition is to check whether the enthalpy of the outside air is lower than the second predetermined limit value of enthalpy is tested.

When the conditions of the transition 313 are satisfied, the method implements the control step 303 of the cooling system 105 according to the second operating mode B.

And if the internal temperature is lower than the set point and if the external temperature is lower than the first predetermined limit value 170 and the second predetermined limit value 175, then the control step 301 of the cooling system 105 according to the first operating mode A is activated.

The cooling method 300 is thus implemented continuously by a microprocessor of the control automaton 190.

Claims

1. Data center (10) having at least one server bay (1 10) and a cooling system (105) for each server bay, characterized in that it comprises:

at least one external temperature sensor (155) sensing a temperature external to the data center,

wherein the cooling system comprises:

at least one cold generating device (135) comprising a reactive medium in a reactor (145), a reservoir comprising a fluid and means for circulating (140) the fluid between the reservoir and the reactor, the fluid and the medium a reagent producing a reversible thermochemical reaction by a supply of energy, the vaporization of the fluid between the reservoir and the heat-absorbing reactor,

at least one air cooling device (125) comprising an evaporative heat exchanger between the external air (130) of the data center environment and the indoor air (120) at the data center,

at least one control automaton (190) of the cooling system as a function of the external temperature and a representative variable (225) depending on a state of the thermochemical reaction of the cold production device:

in a first operating mode (A) when the external temperature is lower than a first predetermined limit value (170), in which the air cooling device is activated without evaporation,

in a second operating mode (B) when the external temperature is between the first predetermined limit value and a second predetermined limit value (175), and depending on the variable, in which the air cooling device is activated with evaporation,

- according to a third operating mode (C) when the external temperature is greater than the second predetermined limit value, and / or depending on the variable, in which the cold generating device and the air cooling device are activated.

Data center (10) according to claim 1, which comprises an internal temperature sensor at the data center and in which the controller (190) controls the cooling system (105) according to the third mode of operation ( C) when the internal temperature is greater than a third predetermined limit value (180) during a first predetermined duration.

Data center according to claim 2, wherein once the cooling system (105) is controlled according to the third mode of operation (C), the controller (190) controls the cooling system according to the first operating mode (A) or the second operating mode (B) if the internal temperature is lower than the third predetermined limit value.

The data center (10) according to one of claims 1 to 3, wherein the cooling system (105) comprises a cold energy storage tank (230) comprising water, the energy storage refrigeration being effected by changing the phase of the water from a liquid phase to a solid phase, the cooling energy being stored when the cooling system is controlled according to the first operating mode (A), the cooling energy being consumed when the cooling system is controlled according to the second and / or the third operating mode (B, C).

Data center (10) according to claim 4, which comprises at least one solar panel (215) or at least one fatal thermal energy source (220) producing thermal energy supplying the cold generating device ( 135) to reverse the thermochemical reaction.

6. Data center (10) according to one of claims 1 to 5, which comprises a means for capturing the mass enthalpy (160) of the outside air near the data center, when the enthalpy mass is greater than a first predetermined limit value of mass enthalpy, the cold generating system (105) is activated according to the third mode (C) until the external mass enthalpy is less than a second predetermined limit value of mass enthalpy for a second predetermined duration.

7. Data center (10) according to one of claims 1 to 6, which comprises a meteorological data capture device (170), at least one predetermined limit value (170, 175, 180) being modified according to the data meteorological conditions

A method of cooling (300) a data center (10) having at least one server bay (1 10) and a cooling system (105) comprising:

at least one cold generating device (135) comprising a reactive medium in a reactor (145), a reservoir comprising a fluid and means for circulating the fluid (140) between the reservoir and the reactor, the fluid and the medium reagent producing a reaction thermochemical reversible by a supply of energy, the vaporization of the fluid between the reservoir and the heat-absorbing reactor,

at least one air cooling device (125) comprising an evaporative heat exchanger between external air (130) of the data center environment and the indoor air (120) at the data center,

characterized in that it comprises the following steps:

capturing (302, 304, 305, 308, 313) a temperature outside the data,

determining a representative variable (225) dependent on a state of the thermochemical reaction of the cold generating device,

- control (301, 303, 309) of the cooling system:

- (301) according to a first operating mode (A) when the external temperature is lower than a first predetermined limit value (170), wherein the air cooling device is activated without evaporation,

- (303) according to a second operating mode (B) when the external temperature is between the first predetermined limit value and a second predetermined value (175), and depending on the variable, in which the air cooling device is activated with evaporation,

- (309) according to a third operating mode (C) when the external temperature is higher than the second predetermined limit value, and / or depending on the variable, in which the cold generating device and the air cooling device are activated.