Water Cooler

Abstract

The present invention relates to a water cooler, which comprises a refrigeration device, a water circuit in which a water flow to be cooled circulates, and a fan that generates an air flow sucked from the outside. The refrigeration device comprises a refrigerant circuit, which works in a closed loop and comprises a compressor, a condenser, an expansion valve and an evaporator. The condenser is configured to release heat from the refrigerant to the air flow under the action of the fan, and the evaporator is configured to absorb heat from the water flow to cool it. The water cooler also comprises a free cooling heat exchanger, which is configured to be exposed to the air flow and can be connected to the water circuit. The water cooler comprises a controllable air flow guiding device, which is adapted to selectively: guide the air flow away from the heat exchanger in a mechanical cooling configuration in which the refrigeration device is running and the heat exchanger is disconnected from the water circuit; or guide the air flow through the heat exchanger in a free cooling configuration in which the refrigeration device is stopped and the heat exchanger is connected to the water circuit.

Description

Technical Field

[0001] The invention relates to a water cooler. Background Art

[0002] Water chillers are used in buildings to cool water that is supplied to air handling units installed in various rooms into which fresh air is blown. In large rooms, such as conference rooms or data centers, fresh air is always needed, so the water may need to be cooled even when the outside temperature is lower than the water temperature.

[0003] In some places where the outside temperature is usually lower, free cooling is used, i.e. the water is directly renewed by heat exchange with the outside air, because free cooling has good efficiency and low energy costs. Therefore, free cooling is mainly used in conference rooms or data centers.

[0004] The water chiller may also include a refrigeration device including a refrigerant thermodynamic circuit to operate mechanical cooling. Where free cooling is possible at certain times, although mechanical cooling is still required in the summer due to high temperatures, a water chiller that can operate in both modes may be required. However, in most cases, a building has only two different water chillers for each mode, resulting in high costs, large volume and large footprint.

[0005] Some water chillers have a water circuit in parallel with the refrigerant circuit and have a condenser of the refrigeration unit which is connected in series with the free cooling heat exchanger relative to the air flow so as to be able to selectively operate both modes within the same system. However, placing the condenser of the refrigeration unit in series with the free cooling heat exchanger means that the air flow must circulate through both exchangers in sequence. This doubles the pressure drop generated during the passage of the air through these heat exchangers, causing high power consumption on the fan of such a water chiller. Therefore, such a water chiller has a lower efficiency than a chiller that does not have a free cooling coil installed in series with the condenser. Summary of the invention

[0006] The object of the present invention is to provide a new water cooler which is better adapted to various temperature conditions at its installation location, thereby performing water cooling at a lower cost.

[0007] To this end, the present invention relates to a water cooler, the water cooler comprising:

[0008] - at least one refrigeration unit,

[0009] - a water circuit in which the water to be cooled circulates,

[0010] - at least one fan which generates a flow of air sucked in from the outside;

[0011] The refrigeration device comprises a refrigerant circuit working in a closed loop, the refrigerant circuit comprising a compressor, at least one condenser, an expansion valve and an evaporator, the condenser being configured to release heat from the refrigerant to an air flow under the action of the at least one fan, the evaporator being configured to absorb heat from a water flow to cool the water flow, wherein the water cooler further comprises at least one free cooling heat exchanger, the at least one free cooling heat exchanger being configured to be exposed to the air flow and connectable to the water circuit, and wherein the water cooler comprises a controllable air flow guiding device, the air flow guiding device being adapted to selectively:

[0012] - directing the air flow away from the at least one free cooling heat exchanger in a mechanical cooling configuration in which the refrigeration plant is running and the at least one free cooling heat exchanger is disconnected from the water circuit; or

[0013] - directing an air flow through the at least one free cooling heat exchanger in a free cooling configuration, in which the refrigeration plant is stopped and the at least one free cooling heat exchanger is connected to a water circuit.

[0014] Thanks to the invention, with the same equipment, free cooling and mechanical cooling can be performed depending on the outside air temperature conditions, thus achieving better performance while keeping the energy costs low and without having to use two different equipments.

[0015] According to other advantageous but not mandatory aspects of the invention, such a water cooler may include one or more of the following features:

[0016] The water cooler comprises a temperature sensor configured to measure an ambient air temperature outside the water cooler and a control unit configured to operate the water cooler in a mechanical cooling configuration or in a free cooling configuration, respectively, depending on whether the ambient air temperature is above or below a temperature threshold, respectively.

[0017] The control unit is configured to control the controllable closing device, the refrigeration system and the valve connecting the at least one free cooling heat exchanger to the water circuit.

[0018] - The controllable air flow guiding device is formed by grids which are movable between a closed position, in which the grids form panels that prevent the air flow through the grids and guide the air flow towards at least one free-cooling heat exchanger, and an open position, in which the air flow passes through the grids away from the at least one free-cooling heat exchanger.

[0019] - At least one condenser is arranged on a vertical lateral side of the water cooler and at least one free cooling heat exchanger is arranged on the same vertical side of the water cooler above the at least one condenser.

[0020] - At least one free cooling heat exchanger extends in vertical alignment with at least one condenser.

[0021] - At least one free cooling heat exchanger has a V-shape protruding from a vertically aligned portion of at least one condenser.

[0022] At least one free-cooling heat exchanger and a controllable closing device are arranged on the top side of the water cooler above the at least one fan.

[0023] At least one free cooling heat exchanger and a controllable closing device are provided as an additional module to be installed on top of an existing water cooler.

[0024] - The water cooler comprises two symmetrical subassemblies, each subassembly comprising at least one condenser, at least one free cooling heat exchanger, at least one fan and a set of controllable air flow guiding devices, the two symmetrical subassemblies being arranged on either side of a central plane and symmetrical with respect to the central plane. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Exemplary embodiments according to the invention and including further advantageous features of the invention are described below with reference to the accompanying drawings, in which:

[0026] - Figure 1 is a schematic diagram showing a water cooler according to a first embodiment of the present invention, the water cooler operating in a mechanical cooling configuration;

[0027] - Figure 2 yes Figure 1 A schematic diagram of a water cooler operating in a free cooling configuration;

[0028] - Figure 3 is a schematic diagram showing a water cooler according to a second embodiment of the present invention, the water cooler operating in a mechanical cooling configuration;

[0029] - Figure 4 yes Figure 3 Schematic diagram of a water chiller operating in a free cooling configuration. DETAILED DESCRIPTION

[0030] Figure 1A water cooler 2 is shown. The water cooler 2 is mounted on a horizontal floor 6. The floor width W of the water cooler 2 represents the horizontal space or footprint that the water cooler 2 occupies on the floor 6. The water cooler 2 may include a frame 4 located on the floor 6. The axis X represents the vertical direction.

[0031] The purpose of the water cooler 2 is to cool water for supplying an air handling unit (not shown) which blows cold air into a room of a building, such as a workspace, a conference room, a data center, etc. Therefore, the water cooler 2 comprises a refrigeration device 8 and a water circuit 10 in which a water flow 100 to be cooled circulates for supplying the air handling unit (not shown). The circulation of water in the water circuit 10 is driven by a pump 102. The pump 102 may be located outside the water cooler 2, such as Figure 1 As shown in , or can be located inside the water cooler 2, such as Figure 2 as shown in .

[0032] According to a variant, the water cooler 2 may comprise more than one refrigeration device 8 .

[0033] The water cooler 2 further comprises at least one fan 12, which forces an ambient air flow F1 to circulate from the outside of the water cooler 2 through the frame 4 to the inside of the water cooler 2. In one embodiment, the water cooler 2 may comprise two fans 12. The air flow F1 generated by the fans 12 has a substantially vertical direction along the axis X. The function of the fans 12 is disclosed more precisely below.

[0034] The refrigeration device 8 comprises a refrigerant circuit 80 which works in a closed loop and comprises a compressor 82, at least one condenser 84, an expansion valve 86 and an evaporator 88. The circulation direction of the refrigerant in the refrigerant circuit 80 is indicated by arrows. During high-load operation of the refrigeration device 8, in a steady state, the refrigerant circulates in these four components in sequence according to a thermodynamic cycle, which is briefly described below.

[0035] In the compressor 82 , the refrigerant is in a gaseous state and is compressed from a low pressure to a high pressure, which increases the temperature of the refrigerant from a low temperature to a high temperature.

[0036] In the condenser 84, the refrigerant is in a two-phase state, including gas refrigerant and liquid refrigerant, and is condensed into a liquid state by the condenser 84 through heat exchange with the air flow F1, and the air flow F1 is forced across the condenser 84 by the fan 12. The refrigerant is at a temperature higher than the temperature T of the ambient air around the water cooler 2, and the refrigerant releases heat to the air flow F1 under the action of the fan 12.

[0037] In the expansion valve 86 , the refrigerant is placed under low pressure, which reduces the temperature of the refrigerant to a low temperature while evaporating the refrigerant into a two-phase state.

[0038] In the evaporator 88, the refrigerant is in a two-phase state including gas refrigerant and liquid refrigerant, and is evaporated into a gaseous state by exchanging heat with the water flow 100 circulating in the evaporator 88. The refrigerant at a low temperature entering the evaporator 88 absorbs heat from the water flow 100 to be cooled, which is at a higher temperature than the temperature of the refrigerant. The water flow 100 leaves the evaporator 88 at a lower temperature than the temperature before entering the evaporator 88.

[0039] In an embodiment, the water cooler 2 includes a plurality of condensers 84. At least one of the condensers 84 may be vertical and mounted along a lateral side of the water cooler 2 (eg, vertical sides 42 and 44 of the water cooler 2).

[0040] In addition to or as an alternative to the vertical condensers 84, the water cooler 2 may also include other condensers 84 mounted closer to the inside of the water cooler 2. These internal condensers 84 may have an inclined shape.

[0041] The water cooler 2 further comprises at least one free cooling heat exchanger 14, which is an air-water exchanger, also known as a liquid circulation coil or a dry cooler. The free cooling heat exchanger 14 is connected to the water circuit 10 and is configured to be exposed to the air flow F1 so as to perform free cooling. Free cooling consists in cooling the water flow 100 by direct heat exchange between the water and the air flow F1, without having to rely on the refrigeration device 8, in which the refrigerant must first be cooled by the outside air and then the water can be cooled.

[0042] The free cooling heat exchanger 14 comprises an orifice, not shown, through which the air flow F1 passes to the outside of the water cooler 2. The free cooling heat exchanger 14 extends in a vertical direction. For example, the water cooler 2 may comprise two free cooling heat exchangers 14 arranged on two opposite sides of the water cooler 2.

[0043] The water cooler 2 further comprises a controllable air flow guiding device adapted to selectively:

[0044] directing the air flow F1 towards the outside of the water cooler 2 and away from the free cooling heat exchanger 14 in a mechanical cooling configuration in which the refrigeration device 8 is running and the free cooling heat exchanger 14 is disconnected from the water circuit 10; or

[0045] The air flow F1 is directed towards the free cooling heat exchanger 14 in a free cooling configuration in which the refrigeration device 8 is stopped and the free cooling heat exchanger 14 is connected to the water circuit 10 .

[0046] The controllable air flow guiding device can be formed by a grille 16 which can be in a closed position (in Figure 2 ) and the open position (shown in Figure 1 ), in which closed position the grids form a panel that prevents the air flow F1 from passing vertically through the grids 16 along the axis X and directs the air flow F1 toward the free cooling heat exchanger 14 in a manner transverse to the axis X, and in which open position the air flow F1 passes vertically through the grids 16 along the axis X toward the outside of the water cooler 2.

[0047] The water cooler 2 may include: a temperature sensor 18 configured to measure an ambient air temperature T; and a control unit 20 configured to control the ambient air temperature T to be higher or lower than a temperature threshold T according to the ambient air temperature T. 最大 The water cooler 2 is operated in a mechanical cooling configuration or in a free cooling configuration, respectively.

[0048] The operation of the water cooler 2 will now be described. In some locations, weather conditions may result in many days of the year with an average outside temperature T below a temperature threshold T 最大 (The temperature threshold may be 18°C). 最大 In this temperature condition, free cooling is considered to be effective and allows cooling the water with a relatively high coefficient of performance (COP). Under such temperature conditions, operating the water cooler 2 in a mechanical cooling mode consumes more energy, i.e. the COP is lower. Therefore, it is advantageous to operate the water cooler 2 in a free cooling configuration by closing the grid 16. The closed grid 16 forms a panel facing the fan 12 in the vertical direction. The air flow F1 is sucked by the fan 12 through the condenser 84 and the frame 4 and then blown out by the fan 12 along the axis X. The air flow F1 is blocked by the closed grid 16 and is therefore prevented from traveling vertically and is forced to pass through the free cooling heat exchanger 14 towards the lateral side of the water cooler 2. The water circuit 10 is connected to the free cooling heat exchanger 14 so as to exchange heat between the air flow F1 and the water flow 100. During this free cooling configuration, the refrigeration device 8 is stopped, for example by stopping the operation of the compressor 82, to save energy. In the free cooling configuration, the air flow F1 passes through the condenser 84 (located upstream of the fan 12) and then through the free cooling heat exchanger 14 (located downstream of the fan 12). The pressure drop and subsequent power consumption caused by the air flow path are largely compensated by the high efficiency of free cooling and the stopping of the compressor 82.

[0049] When the ambient air temperature T is higher than the temperature threshold T 最大 In the case of , the temperature difference between the temperature of the water flow 100 and the ambient air temperature T may not be sufficient to obtain effective free cooling. Therefore, the water cooler 2 must be operated in a mechanical cooling configuration. For example, the refrigeration device 8 is started by starting the compressor 82. The grid 16 is opened, thereby forming a large orifice directly above the fan 12. The air flow F1 is sucked in through the frame 4 and the condenser 84, and then blown out by the fan 12 along the axis X. The air flow F1 can flow through the free cooling heat exchanger 14 and through the opened grid 16. However, since the free cooling heat exchanger 14 produces a pressure drop, the air flow F1 is spontaneously driven vertically through the opened grid 16, which will produce a much lower pressure drop. Therefore, the air flow F1 only passes through the condenser 84, thereby avoiding any adverse pressure drop that would occur in the prior art air cooler with a condenser and a free cooling heat exchanger connected. Therefore, the water cooler 2 benefits from the full efficiency of mechanical cooling. The free cooling heat exchanger 14 is disconnected from the water circuit 10 to further save energy consumed by the pump 102 to circulate water towards, through and from the free cooling heat exchanger 14 .

[0050] The control unit 20 is configured to control the grid plate 16. The grid plate 16 can be driven by a motor (not shown) controlled by the control unit 20 between a closed position and an open position of the grid plate.

[0051] The control unit 20 controls the refrigeration system by, for example, sending a start control signal or a stop control signal to the compressor 82 .

[0052] The water circuit 10 may include a valve (eg, a three-way valve) controlled by the control unit 20 for connecting or disconnecting the free cooling heat exchanger 14 from the water circuit 10. The water circuit 10 may include a valve 104, which is connected to the water circuit 10. Figure 1 In a mechanical cooling configuration, water flow 100 is directed toward evaporator 88, or in Figure 2 In the free cooling configuration of the present invention, the water flow 100 is directed via the supply line 105 towards the free cooling heat exchanger 14. The water circuit 10 comprises a second valve 106 which is connected to the free cooling heat exchanger 14 via a return line 107. Figure 1 In FIG. 1 , valve 106 directs water flow 100 toward the outside of water cooler 2 and blocks water flow 100 from traveling toward return line 107. Figure 2 In the embodiment, valve 106 blocks water flow 100 from traveling toward evaporator 88. To simplify the drawings, Figure 1 The supply line 105 and the return line 107 are not shown. To simplify the drawings, Figure 2 Elements of the refrigeration device 8 other than the condenser 84 are not shown.

[0053] The grid 16 is preferably arranged on the top side 46 of the water cooler 2 and above the fan 12 .

[0054] The free cooling heat exchanger 14 may be arranged on the same vertical side of the water cooler 2 as the vertical condensers 84 and above these condensers. Figure 1 and Figure 2 In the advantageous embodiment shown in , the free cooling heat exchanger 14 can be extended in a manner vertically aligned with the vertical condenser 84. This enables the width W of the water cooler 2 to remain unchanged. Therefore, the footprint of the water cooler 2 is not increased due to the fact that additional components for free cooling are added. Only the height of the water cooler 2 is increased.

[0055] The free cooling heat exchanger 14 and the grid 16 can be provided as an additional module 22 to be installed on top of an existing water cooler. The free cooling heat exchanger 14 and the grid 16 are located on top of the fan 12, which usually form the upper side of a standard water cooler, and can be installed in a pre-assembled module, which can be easily installed on an existing water cooler. To complete the installation of the pre-assembled module, the operator has to provide the necessary water connection lines and connect the pre-assembled module with the control unit 20, which can be provided as a supplementary component of the pre-assembled module.

[0056] In this exemplary embodiment, the water cooler 2 includes two symmetrical subassemblies 24. Each subassembly 24 includes a vertical condenser 84, an inclined condenser 84, a free cooling heat exchanger 14, a fan 12 and a set of grid plates 16. The subassemblies 24 are arranged on both sides of the center plane extending along the axis X of the water cooler 2 and are symmetrical about the center plane. The center plane is contained in the central partition wall 48 of the water cooler 2. More generally, each subassembly 24 can include at least one condenser 84, at least one free cooling heat exchanger 14, at least one fan 12 and a set of controllable air flow guiding devices.

[0057] Figure 3 and Figure 4 A second embodiment of the invention is shown in FIG. In this embodiment, similar elements to those of the first embodiment have the same reference numerals and operate in the same manner. Only the differences from the first embodiment are described in detail below.

[0058] exist Figure 3 and Figure 4In the embodiment of the present invention, the free cooling heat exchanger 14 has a V-shape protruding from the vertically aligned portion of the vertical condenser 84, rather than being in the vertically aligned portion of the vertical condenser 84. In this case, the width of the additional pre-assembled module is increased, but the floor width W is not increased, and this V-shape can reduce the overall height of the water cooler 2.

[0059] The V-shaped free cooling heat exchanger 14 may be arranged as two heat exchangers 140 that are angled relative to each other.

[0060] The technical features and modifications of the embodiments disclosed above may be combined to form new embodiments of the present invention.

Claims

1. A water cooler (2), comprising: - at least one refrigeration device (8), a water circuit (10) in which a water flow (100) to be cooled circulates, - at least one fan (12) generating an air flow (F1) sucked in from the outside; The refrigeration device (8) comprises a refrigerant circuit (80) operating in a closed loop. The refrigerant circuit (80) includes a compressor (82), at least one condenser (84), an expansion valve (86) and an evaporator (88). The condenser (84) is configured to release heat from the refrigerant to the air flow (F1) under the action of the at least one fan (12), The evaporator (88) is configured to extract heat from the water flow (100) to cool the water flow (100). Wherein, the water cooler (2) further comprises: a temperature sensor (18) configured to measure the ambient air temperature outside the water cooler (2), a control unit (20) configured to operate the water cooler (2) in a mechanical cooling configuration or in a free cooling configuration, respectively, depending on whether the ambient air temperature is above or below a temperature threshold, respectively, at least one free-cooling heat exchanger (14) configured to be exposed to said air flow (F1), and a valve connecting said at least one free-cooling heat exchanger (14) to said water circuit (10), Controllable air flow guiding device, The control unit (20) is configured to control the refrigeration device (8), the valve and the air flow guiding device, wherein the air flow guiding device is adapted to selectively: - directing the air flow (F1) away from the at least one free cooling heat exchanger (14) in a mechanical cooling configuration in which the refrigeration device (8) is in operation and the at least one free cooling heat exchanger (14) is disconnected from the water circuit (10); or - directing the air flow (F1) through the at least one free cooling heat exchanger (14) in a free cooling configuration in which the refrigeration device (8) is stopped and the at least one free cooling heat exchanger (14) is connected to the water circuit (10).

2. The water cooler according to claim 1, wherein: The controllable air flow guiding device is formed by a grille (16) which is movable between a closed position, in which the grille forms a panel to prevent the air flow (F1) from passing through the grille and to guide the air flow (F1) towards the at least one free cooling heat exchanger (14), and an open position in which the air flow (F1) passes through the grille (16) away from the at least one free cooling heat exchanger (14).

3. The water cooler according to claim 1, wherein: The at least one condenser (84) is arranged on a vertical lateral side of the water cooler (2), and wherein the at least one free cooling heat exchanger (14) is arranged on the same vertical side of the water cooler (2) above the at least one condenser (84).

4. The water cooler according to claim 3, wherein: The at least one free cooling heat exchanger (14) extends in vertical alignment with the at least one condenser (84).

5. The water cooler according to claim 3, wherein: The at least one free cooling heat exchanger (14) has a V-shape protruding from a vertically aligned portion of the at least one condenser (84).

6. The water cooler according to claim 1, wherein: The at least one free cooling heat exchanger (14) and the controllable air flow guiding device are arranged on a top side (46) of the water cooler (2) above the at least one fan (12).

7. The water cooler according to claim 6, wherein: The at least one free cooling heat exchanger (14) and the controllable air flow guiding device are provided as an add-on module (22) to be mounted on top of an existing water cooler.

8. The water cooler according to claim 1, wherein: The water cooler comprises two symmetrical subassemblies (24), each subassembly comprising at least one condenser (84), at least one free cooling heat exchanger (14), at least one fan (12) and a set of controllable air flow guiding devices, wherein the two symmetrical subassemblies (24) are arranged on both sides of a central plane (48) and are symmetrical about the central plane (48).

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