JP5824736B2 - Free cooling chiller freeze prevention device - Google Patents

Description

  The present invention relates to an antifreezing device for a free cooling chiller having a free cooling function for exchanging heat between outside air and a coolant.

  Conventionally, with respect to a heat exchanger provided in a cooling device such as a chiller, cooling is performed using a low temperature environment of the outside air by blowing outside air, and further, from a nozzle for watering provided in a watering mechanism to a heat exchanger. As a cooling device that performs water spraying and uses the water temperature of the mist generated by water spraying and the latent heat at the time of evaporation to further increase the cooling capacity, the auxiliary cooling device disclosed in Patent Literature 1 and Patent Literature 2 are disclosed. Air-cooled heat exchangers are known.

  The auxiliary cooling device of Patent Document 1 is an auxiliary cooling device for a condenser of an air conditioner that includes a nozzle that sprays water toward the condenser of the air conditioner to spray water, and water that is sprayed from the nozzle. The air-cooled heat exchanger having an average particle size of 200 μm or more and the air-cooled heat exchanger disclosed in Patent Document 2 allow air to pass through by driving a fan disposed above the heat exchanger body. The nozzle includes a nozzle for ejecting water in a flat shape, and the nozzle is disposed at a position opposite to the fan across the heat exchanger body, and sprays water on an upper portion of the heat exchanger body. When it is done, it spreads in a substantially horizontal direction.

Japanese Patent Laid-Open No. 2000-018769 JP 2007-327736 A

  However, the conventional cooling device (auxiliary cooling device, air-cooled heat exchanger) provided with the nozzle for watering described above has the following problems.

  First, when installed outdoors like a free cooling chiller, freezing of the watering mechanism including the nozzle in the cold season becomes a problem. In the cold season, the outside air itself becomes considerably cold and the frequency of watering is low, so the watering function is often stopped from the viewpoint of anti-freezing measures. Even if it is, watering may be necessary, and the discontinuation of the watering function is a factor that reduces the original capacity of the free cooling chiller.

  Secondly, since anti-freezing measures are usually taken to prevent freezing at night after operation is stopped, even in the case of a watering mechanism, water in the nozzle and piping should be drained after operation is stopped. However, this type of watering nozzle does not always spray water during operation, and sprays water irregularly based on temperature conditions during operation, and the nozzle spray nozzle has a small diameter. Because it becomes a mouth, there is a problem that it tends to freeze during operation, and normal anti-freezing measures cannot be applied.

  An object of the present invention is to provide a freezing chiller anti-freezing device that solves the problems in the background art.

  In order to solve the above-described problems, the present invention provides the internal cooling system M1 using the cooling device 3 that cools the cooling liquid L, and the outside air heat that exchanges heat between the outside air A blown by the blower fan 4 and the cooling liquid L. The outside air cooling system M2 having the exchanger 5 (5p, 5q), the control system Mc that performs control when cooling the coolant L using the internal cooling system M1 and the outside air cooling system M2, and the blowing direction Fw of the outside air A An anti-freezing device for a free cooling chiller U comprising a spraying nozzle Ns... Having a spray nozzle Ns... Capable of spraying water Lwm on the outdoor air heat exchanger 5 by being disposed at an upstream position of the outdoor air heat exchanger 5 1, the connection port 7 to which the compressed air Ap supply source 100 can be connected, and the connection port 7 are connected to at least the spray nozzle Ns via an air supply valve 8v for supplying or stopping the compressed air Ap. Vs. The air supply circuit 8 connected to the downstream side of the water supply valve 9 for supplying or stopping water supply, and at least when the ambient temperature To exceeds the set temperature Ts, the air supply valve 8v is switched to the closed side, and the water supply Compression that controls opening and closing of the valve 9 and switches the water supply valve 9 to the closed side when the ambient temperature To is equal to or lower than the set temperature Ts, and switches to the closed side after switching the air supply valve 8v to the open side for the set time Zs. And a control system Mc having an air supply control function.

  In this case, according to a preferred aspect of the present invention, the supply source 100 of the compressed air Ap can use an existing supply source in the facility where the free cooling chiller U is installed. Further, the air supply circuit 8 is connected to the downstream side of the water supply valve 9 so that the water Lwm remaining between the spray nozzles Ns... A valve 11 can be provided. At this time, the discharge switching valve 11 can be connected to the coolant tank 14 on the downstream side. On the other hand, the air supply circuit 8 has an air supply in which the connection port 7 is connected to the upper end of the outside air heat exchanger 5 (5p, 5q) via a second air supply valve 12v that supplies or stops the compressed air Ap. A second circuit 12 can be provided, and the air supply second circuit 12 includes an air vent circuit 13v that is connected to the downstream side of the second air supply valve 12v and opens or shuts off to the atmosphere. Can be provided. On the other hand, the outside air cooling system M2 can be provided with a coolant circulation circuit 15 for circulating the coolant L stored in the coolant tank 14 to the outside air heat exchanger 5, and the downstream side of the air vent valve 13v It can be exposed to the atmosphere inside the tank 14. Furthermore, the coolant tank 14 can be provided with a heater 16 for heating the coolant L stored therein.

  According to the anti-freezing device 1 for the free cooling chiller U according to the present invention having such a configuration, the following remarkable effects can be obtained.

  (1) When there is a possibility of freezing, the compressed air supply control function supplies the compressed air Ap supplied from the supply source 100 to the watering mechanism 6, so that the water Lwm remaining inside is sprayed. Ns can be forcibly discharged. As a result, freezing of the watering mechanism 6 including the spray nozzles Ns... During the cold season can be reliably prevented, and the utilization rate of the watering mechanism 6 can be increased. The original ability of the free cooling chiller U can always be exhibited.

  (2) According to a preferred embodiment, if an existing supply source is used as the compressed air Ap supply source 100 for the facility where the free cooling chiller U is installed, it is not necessary to prepare a separate supply source for the compressed air Ap. Therefore, it can contribute to cost reduction and installation space reduction. In particular, this type of free cooling chiller U is often installed in a factory or the like where the supply source 100 of the compressed air Ap is already installed, so that the advantage of using the existing supply source 100 can be enjoyed effectively.

  (3) By connecting to the air supply circuit 8 on the downstream side of the water supply valve 9 according to a preferred embodiment, the water Lwm remaining between the spray nozzle Ns... And the air supply valve 8v (or the water supply valve 9) is made outside. If the discharge switching valve 11 that can discharge is provided, even if the compressed air Ap is not used because there is no supply source of the compressed air Ap at the place where the free cooling chiller U is installed, the remaining water Lwm is removed. Can be discharged outside by natural fall. Therefore, it can be used in any situation where the compressed air Ap supply source is present or absent, and is excellent in versatility and adaptability.

  (4) If the downstream side of the discharge switching valve 11 is connected to the coolant tank 14 according to a preferred embodiment, the remaining water Lwm can be stored in the coolant tank 14, so that the coolant L stored in the coolant tank 14 is used. When water Lwm is used, waste of water Lwm can be eliminated.

  (5) According to a preferred embodiment, the upper end of the outdoor air heat exchanger 5 (5p, 5q) is connected to the air supply circuit 8 via the second air supply valve 12v for supplying or stopping the compressed air Ap. If the air supply second circuit 12 connected to the external air heat exchanger 5 is provided, the compressed air Ap can be supplied to the outdoor air heat exchanger 5 at an arbitrary interval and at an arbitrary time. At the time of use, by supplying the compressed air Ap to the outside air heat exchanger 5, the coolant L remaining inside the outside air heat exchanger 5 can be forcibly removed, whereby the outside air heat exchanger 5, Furthermore, effective freezing prevention for the outside air cooling system M2 can be achieved.

  (6) According to a preferred embodiment, if the second air supply circuit 12 is provided with an air vent circuit 13 having an air vent valve 13v that is connected to the downstream side of the second air supply valve 12v and opens or shuts off to the atmosphere, Even when the compressed air Ap is not used due to the absence of a supply source of the compressed air Ap at the place where the free cooling chiller U is installed, the remaining coolant L can be extracted by natural fall. .

  (7) According to a preferred embodiment, the outside air cooling system M2 is provided with a coolant circulation circuit 15 that circulates the coolant L stored in the coolant tank 14 to the outside air heat exchanger 5, and the downstream side of the air vent valve 13v When facing the atmosphere inside the cooling liquid tank 14, the air vent valve 13 v can smoothly return the cooling liquid L to the cooling liquid tank 14 by performing air venting when the remaining cooling liquid L is extracted. At the same time, at the time of the resupply process for filling the cooling liquid L again to the air vent circuit 13 from which the cooling liquid L has been extracted, the internal air and the cooling liquid L can be released to the inside of the cooling liquid tank 14, so that a quick resupply process is possible. It can be performed.

  (8) If the heater 16 for heating the coolant L stored inside is provided in the coolant tank 14 according to a preferred embodiment, the ambient temperature may be greatly reduced, and the coolant may freeze to the entire coolant L. Even if there is, the coolant L stored in the coolant tank 14 is warmed by the heater 16, and further circulated by the circulation pump of the outside air cooling system M2, thereby reliably preventing the coolant L from freezing. be able to.

The flowchart which shows the freeze prevention process procedure of the watering mechanism with which the freeze prevention apparatus which concerns on suitable embodiment of this invention is equipped, Overall system circuit diagram of a free cooling chiller equipped with the antifreezing device, Block system diagram of the control system of the anti-freezing device, Side internal structure diagram of a free cooling chiller equipped with the antifreezing device, Front internal structure diagram of a free cooling chiller equipped with the antifreezing device, Timing chart of signals of each part at the time of freeze prevention treatment of the watering mechanism provided in the freeze prevention device, Correspondence table of the ambient temperature of the internal cooling system provided in the freeze prevention device and the freeze prevention mode to be used, Timing chart of signals of each part at the time of execution of circulating anti-freezing mode of the internal cooling system provided in the anti-freezing device, Principle circuit diagram showing a modification of the air supply valve provided in the anti-freezing device, External perspective view of a free cooling chiller according to a modified embodiment of the present invention,

  Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.

  First, in order to facilitate understanding of the present invention, the entire structure of a free cooling chiller U including the antifreezing device 1 according to the present embodiment will be described with reference to FIGS.

  As shown in FIGS. 4 and 5, the free cooling chiller U includes a casing 21 that is formed in a rectangular parallelepiped shape as a whole. The upper interior of the casing 21 is configured as an outside air heat exchange chamber Rc, and the lower interior is a storage chamber. Configure as Ri. A blower fan 4 covered with a hood 22 is disposed at the upper end of the casing 21. Accordingly, when the blower fan 4 rotates, the inside of the outside air heat exchange chamber Rc is sucked, and the side of the hood 22 becomes the exhaust port 22e.

  Inside the outside air heat exchange chamber Rc, the condenser 18 of the internal cooling system M1 and the outside air heat exchanger 5 of the outside air cooling system M2 are disposed. In this case, as shown in FIG. 2, the condenser 18 becomes a part of the refrigeration cycle C in which the refrigerant circulates, and this refrigeration cycle C constitutes the cooling device 3 in the internal cooling system M1. On the other hand, the outside air heat exchanger 5 constitutes an outside air cooling system M2 that performs heat exchange between the outside air A and the coolant L. The cooling device 3 (internal cooling system M1) and the outside air cooling system M2 both have a function of cooling a cooling liquid L described later, and in particular, the outside air cooling system M2 has a free cooling function. In this embodiment, the case where the cooling water Lw is used as the cooling liquid L is illustrated.

  As shown in FIG. 4, the outside air heat exchanger 5 is configured by a combination of a pair of flat heat exchange units 5p and 5q, and has a V shape when viewed from the side in the outside air heat exchange chamber Rc. It arrange | positions as follows. Thus, the blower fan 4 is disposed above the internal space sandwiched between the inner surfaces of the two heat exchange units 5p and 5q, and is disposed at a downstream position in the blower direction Fw with respect to the outdoor air heat exchanger 5. Established. In addition, intake ports 21i and 21i are provided on the side surfaces (front and back) of the casing 21 facing the two heat exchange units 5p and 5q. The heat exchange unit 5p can be implemented in the form of a general heat exchanger in which the cooling liquid pipe through which the cooling water Lw passes is formed in a zigzag shape and a large number of fins for heat radiation are attached to the outer peripheral surface. Is not specified and can be implemented in various forms. The heat exchanging unit 5p is disposed upright (tilted) at a predetermined tilt angle Qc (illustrated as 15 [°]) with respect to the vertical line. The other heat exchanging unit 5q is configured in the same manner as the heat exchanging unit 5p, and is erected (tilted) at an inclination angle Qc of 15 [°] with respect to the vertical line. In this case, the tilt directions of the heat exchange units 5p and 5q are opposite directions. Thereby, as shown in FIG. 4, the outdoor air heat exchanger 5 which becomes V shape seeing from the side is obtained. The two heat exchange units 5p and 5q are used in parallel connection.

  In addition, water retaining sheets 23p and 23q are attached to the outer surfaces of the heat exchange units 5p and 5q on which water Lwm described later is sprayed. As the water retention sheets 23p and 23q, for example, a net member (woven fabric) made of a polypropylene material can be used. Since such a net member has a mesh structure, sufficient air permeability can be secured and necessary water retention can be secured. In this case, the water-retaining sheets 23p and 23q are configured to be detachable from the outer surfaces of the heat exchange units 5p and 5q, and can be replaced with new ones for maintenance or the like. If such water retaining sheets 23p and 23q are attached, the sprayed water Lwm is retained by the water retaining sheets 23p and 23q, and can be evaporated on the water retaining sheets 23p and 23q. Accordingly, since the cooling air generated on the water retention sheets 23p and 23q can be supplied to the outside air heat exchanger 5 and the condenser 18, effective and stable cooling can be performed for both the outside air heat exchanger 5 and the condenser 18. There is an advantage that can be done.

  On the other hand, the condenser 18 is also constituted by a combination of two condensing units 18p and 18q. The condensing unit 18p has a general condenser structure, that is, a structure in which a large number of heat dissipating fins are attached to the outer peripheral surface of a refrigerant pipe unit in which refrigerant pipes through which a refrigerant passes are formed in a zigzag shape. The other condensing unit 18q is configured similarly to the condensing unit 18p, and the two condensing units 18p and 18q are used in parallel connection. And each condensation unit 18p and 18q is arrange | positioned so that it may each overlap with each heat exchange unit 5p and 5q from the downstream of the ventilation direction Fw of the ventilation fan 4, as shown in FIG. With such a configuration, the condenser 18 faces the outside air heat exchanger 5 from the downstream side in the blowing direction Fw, so that there is no dead space when the condenser 18 and the outside air heat exchanger 5 are disposed, In addition to contributing to downsizing, the fan 4 can be easily shared. In addition, since the temperature of the outside air heat exchanger 5 is usually lower than the temperature of the condenser 18, more efficient heat exchange can be performed in consideration of the blowing direction Fw.

  Further, as shown in FIG. 5 (FIG. 4), the storage room Ri includes components of the refrigeration cycle C (internal cooling system M1) excluding the condenser 18, a circulation pump 24 excluding the outside air heat exchanger 5, and the like. The components in the outside air cooling system M2 are disposed, and the coolant tank 14 and the pressure pump 25 for supplying the cooling water Lw to the cooled portion 70 described later are disposed. In this way, if the coolant tank 14 is installed in the lower storage chamber Ri and the outside air heat exchanger 5 is installed in the upper outside air heat exchange chamber Rc, the free cooling chiller U is stopped or in operation. Even when the outside air heat exchanger 5 is not used, the cooling water Lw remaining in the outside air heat exchanger 5 can be caused to flow into the cooling liquid tank 14 by natural fall and be removed. For this reason, the bending shape and angle of the cooling fluid pipe and the piping between the outside air heat exchanger 5 and the cooling fluid tank 14 are considered so that no residue is generated when the cooling water Lw is extracted. In addition, in FIG. 5, 26 shows the compressor in the refrigerating cycle C, 27 shows the control panel containing a switchboard.

  On the other hand, FIG. 2 shows an entire system circuit of the free cooling chiller U. Reference numeral 70 denotes a portion to be cooled such as a machine tool that is cooled by the cooling water Lw supplied from the free cooling chiller U by being connected to the free cooling chiller U. In FIG. 2, M1 represents an internal cooling system, and M2 represents an outside air cooling system having a free cooling function.

  The internal cooling system M1 is configured by the cooling device 3 using the refrigeration cycle C including the condenser 18 described above. Therefore, the refrigerant inlet and the refrigerant outlet of the condenser 18 are connected to the refrigeration cycle main part 31 including the compressor 26 and the electronic expansion valve, and the refrigerant K and the cooling water Lw are further connected to the refrigeration cycle main part 31. By connecting the primary side 32f in the cooler (heat exchanger) 32 that performs heat exchange, a known refrigeration cycle C in which the refrigerant K circulates is configured. Further, the coolant inlet on the secondary side 32 s in the cooler 32 is connected to the supply port 25 i of the coolant tank 14 via the pressure feed pump 25. In this case, the supply port 25 i also serves as the suction port of the pressure pump 25. Further, the coolant outlet on the secondary side 32 s in the cooler 32 is connected to the coolant supply port 33 s to which the cooled portion 70 is connected. The coolant return port 33r to which the cooled portion 70 is connected is connected to the return port 25r of the coolant tank 14 via a return pipe.

  The outside air cooling system M2 includes the outside air heat exchanger 5 described above, and the coolant inlet of the outside air heat exchanger 5 is connected to the supply port 24i of the coolant tank 14 via the circulation pump 24 and the outside air heat. The coolant outlet of the exchanger 5 is connected to the return port 24r of the coolant tank 14 via a return pipe. As a result, a coolant circulation circuit 15 that circulates the coolant Lw stored in the coolant tank 14 to the outside air heat exchanger 5 is configured. In addition, 34 is a bypass valve, 35 is a tank drain valve, and 36 is a water pressure gauge.

  On the other hand, spray nozzles Ns..., Ns... Constituting the water sprinkling mechanism 6 are arranged in the vicinity of the intake ports 21i and 21i. Each of the spray nozzles Ns..., Ns... Is arranged toward the heat exchange units 5p and 5q so as to be sprayed obliquely upward, and in particular, an optimum position and angle are selected so as to be able to diffuse over a wider range. In the case of the illustration, as shown in FIGS. 4 and 5, two spray nozzles Ns, Ns... Separated from each heat exchange unit 5p, 5q, respectively. The number of spray nozzles Ns... Is arbitrary and may be one or three or more for each heat exchange unit 5p, 5q. Each spray nozzle Ns ... is attached on the installation surface of each heat exchange unit 5p, 5q. Thereby, each spray nozzle Ns... Is arranged on the upstream side in the blowing direction Fw with respect to each heat exchange unit 5p, 5q, and is set at a predetermined angle with respect to the outer surface of each heat exchange unit 5p, 5q. Spraying is possible with Qf. It is desirable to set the spray position on the outer surface of the heat exchange units 5p, 5q from the center position to the lower position. Further, as shown in FIG. 4, the predetermined angle Qf is preferably set to 10 [°] ≦ Qf <50 [°] with respect to the outer surfaces of the heat exchange units 5p and 5q. The exemplified predetermined angle Qf is 30 ° (the angle Qcf with respect to the vertical line is 15 °). Note that Qmf shown in FIG. 4 indicates an angle of 45 ° with respect to the vertical line (the predetermined angle Qf is 60 °).

  In this case, the outdoor air heat exchanger 5 (each heat exchange unit 5p, 5q) is disposed in a V shape, and the blower fan 4 is disposed above the air heat exchanger 5 (on the side of the outer surface of each heat exchange unit 5p, 5q). Due to the layout in which the air inlets 21i and 21i are provided, the air blowing direction Fw by the air blowing fan 4 changes in the direction perpendicular to the front and rear of the heat exchange units 5p and 5q. Therefore, the tendency of the air flow rate with respect to each heat exchange unit 5p, 5q increases as the upper side decreases, and decreases as the lower side. Further, since the water Lwm is sprayed obliquely from below, the tendency of the spray amount of the water Lwm to each of the heat exchange units 5p and 5q decreases as the upper side increases, and increases as the lower side. As described above, if the predetermined angle Qf is set so as to satisfy the angle condition of 10 [°] ≦ Qf <50 [°] with respect to the outer surface of the outdoor air heat exchanger 5, the predetermined angle Qf is set with respect to the outer surface of the outdoor air heat exchanger 5. Since the distribution of the amount of air blown by the blower fan 4 and the distribution of the amount of spray by the spray nozzles Ns..., Ns... Can be easily set to a mutually complementary positional relationship, the best result can be obtained from the viewpoint of cooling the whole uniformly. Can do.

  Furthermore, each spray nozzle Ns... Is connected to a water supply port 41 to which water Lwm is supplied via a water supply valve 9 as shown in FIG. An external water supply source (such as a water pipe) is connected to the water supply port 41. In this case, the water supply valve 9 may be an electromagnetic on-off valve that supplies or stops water Lwm to each spray nozzle Ns, or a control valve that can variably control the amount of water Lwm supplied to each spray nozzle Ns. . Reference numeral 42 denotes a water pressure gauge.

  Next, the basic configuration of the freeze prevention device 1 according to the present embodiment will be described with reference to FIGS. 2 and 3.

  As shown in FIG. 2, the freeze prevention device 1 has, as a basic configuration, a connection port 7 to which a compressed air Ap supply source 100 can be connected, and an air supply that supplies or stops the compressed air Ap to the connection port 7. The air supply circuit 8 connected to and communicated with the downstream side of the water supply valve 9 for supplying or stopping water to at least the spray nozzles Ns through the valve 8v, and at least the ambient temperature To is the set temperature Ts. When the temperature exceeds, the air supply valve 8v is switched to the closed side, and the water supply valve 9 using an electromagnetic open / close valve is controlled to open / close, and the water supply valve 9 is closed when the ambient temperature To is lower than the set temperature Ts. And a control system Mc having a compressed air supply control function for switching to the closed side after switching the air supply valve 8v to the open side for the set time Zs. Thereby, the freeze prevention measure with respect to the watering mechanism 6 is achieved.

  In this case, as the supply source 100 for the compressed air Ap, an existing supply source is used in the facility where the free cooling chiller U is installed. Thus, if the existing supply source 100 is used, it is not necessary to prepare a separate supply source of the compressed air Ap, which can contribute to cost reduction and installation space reduction. In particular, this type of free cooling chiller U is often installed in a factory or the like where the supply source 100 of the compressed air Ap is already installed. Therefore, there is an advantage that the advantage of using the existing supply source 100 can be enjoyed effectively. .

  An electromagnetic on-off valve is used as the air supply valve 8v provided in the air supply circuit 8. Accordingly, the air supply valve 8v can be switched to the open side to supply the compressed air Ap to the watering mechanism 6, and the air supply valve 8v can be switched to the closed side to stop the supply of the compressed air Ap to the watering mechanism 6. can do. Further, as shown by a virtual line in FIG. 2, the air supply circuit 8 is connected to the downstream side of the water supply valve 9 so as to communicate with the air supply valve 8 between the spray nozzle Ns and the air supply valve 8v (or the water supply valve 9). It is desirable to provide a discharge switching valve 11 capable of discharging water Lwm remaining in the water to the outside by natural fall. The illustrated discharge switching valve 11 is configured such that the downstream side is connected to the coolant tank 14 so that the remaining water Lwm can flow into the coolant tank 14. Thereby, when water Lwm is used as the coolant L stored in the coolant tank 14, waste of the water Lwm can be eliminated. Thus, if the discharge switching valve 11 is provided in the air supply circuit 8, the compressed air Ap is not used because there is no supply source of the compressed air Ap at the place where the free cooling chiller U is installed. Also, the remaining cooling water Lw can be discharged to the outside by natural fall. Therefore, it can be used in any situation where the compressed air Ap supply source is present or absent, and is excellent in versatility and adaptability.

  On the other hand, FIG. 3 shows the control system Mc, in particular, the control system Mc extracted from only the system related to the freeze prevention device 1. Reference numeral 51 denotes a chiller controller having a computing function for performing various controls in the free cooling chiller U. The chiller controller 51 includes a controller main body 52 including hardware such as a CPU and various drive units. The chiller controller 51 includes a memory 52m, and an operation unit 53 and a display unit 54 are attached. The memory 52m has a program area 52mp for storing a sequence control program for realizing at least a series of operations in the freeze prevention apparatus 1 according to the present embodiment, particularly, a compressed air supply control function, and a set temperature Ts (for example, 5 [° C.]) and the like, and a data area 52md for writing various data including various setting data. The water supply valve 9, the air supply valve 8 v and the circulation pump 24 are connected to the output port of the controller main body 52, and the ambient temperature sensor 55 and the return port temperature sensor 56 are connected to the sensor input port of the controller main body 52. Connect. The ambient temperature sensor 55 is a temperature sensor that detects the temperature of the outside air (ambient temperature To), and is disposed upstream of the outside air heat exchanger 5 in the air blowing direction Fw, as shown in FIG. The return port temperature sensor 56 is a temperature sensor that detects the temperature of the cooling water Lw returned from the cooled part 70 (return liquid temperature Tr), and as shown in FIG. It is disposed near the coolant return port 33r into which the water Lw flows.

  Next, the operation of the basic configuration of the freeze prevention device 1 according to the present embodiment will be described according to the flowchart shown in FIG. 1 with reference to the drawings.

  First, for the free cooling chiller U installed in a factory or the like, as shown in FIG. 2, various connections that are normally required, such as the cooled portion 70 and the power source, are performed, and according to the present embodiment (the present invention), A compressed air Ap supply source 100 already installed in equipment in the factory or the like is connected to the connection port 7. When the installation of the free cooling chiller U is completed, necessary setting items such as the target temperature Tt for the cooling water Lw are set.

  If the power supply of the free cooling chiller U is OFF (including power failure), the air supply valve 8v is switched to the open side because it is a normally open type, and the water supply valve 9 is a normally closed type. Switching to the closed side (steps S1 and S10). And if the power supply of the free cooling chiller U is turned ON, the air supply valve 8v will switch to the close side. Thereby, supply of water Lwm to watering mechanism 6 will be in a water stop state, and supply of compressed air Ap will be in a stop state.

  When the operation of the free cooling chiller U is started, the pressure feed pump 25 is activated, and the cooling water Lw in the coolant tank 14 passes through the pressure feed pump 25, the secondary side 32s of the cooler 32, and the coolant supply port 33s. Then, it is supplied to the cooled part 70. Accordingly, the cooled portion 70 is cooled by the cooling water Lw, and the cooling water Lw warmed by heat exchange is returned from the return port 25r into the cooling liquid tank 14 via the cooling liquid return port 33r. Further, the ambient temperature To is detected by the ambient temperature sensor 55 (step S2). FIG. 6A shows change data of the ambient temperature To.

  In this case, if the ambient temperature To exceeds 5 [° C.] which is the set temperature Ts, the switching position of the air supply valve 8v is maintained on the closed side, and the water supply valve 9 is controlled to be opened and closed according to normal temperature control. (Steps S3 and S4). 6B shows a switching signal Vw for the water supply valve 9, and FIG. 6C shows a switching signal Va for the air supply valve 8v. When the blower fan 4 is in use and the water temperature (detected water temperature) of the cooling water Lw satisfies a predetermined temperature condition such as higher than the set water temperature (set water temperature), the water supply valve 9 is opened. The water Lwm is sprayed from the spray nozzles Ns. Thereby, the cooling capacity is further enhanced by utilizing the water temperature of the mist generated by spraying and the latent heat when evaporating. Further, when the water supply valve 9 is switched to the open side, if the detected water temperature is equal to or lower than the set water temperature, the water supply valve 9 is switched to the closed side.

  On the other hand, it is assumed that the ambient temperature To gradually decreases and becomes 5 [° C.] or less at the time ts shown in FIG. 6 (step S3). Thereby, the water supply valve 9 is switched to the closed side, and the air supply valve 8v is switched to the open side (step S5). As a result, the water is stopped, and the compressed air Ap from the supply source 100 is supplied to the water spray mechanism 6 through the connection port 7 and the air supply valve 8v, and the compressed air Ap is ejected from the spray nozzles Ns. That is, the water Lwm remaining in the watering mechanism 6 is blown away from the spray nozzles Ns by the compressed air Ap, and the watering mechanism 6 is in an empty state. Further, the time measuring process is performed from the time point ts, and when the time point ta shown in FIG. 6 where a preset time Zs (for example, 5 [minutes]) elapses is reached, the ambient temperature To is determined again (step S6). S7, S8). At this time, if the ambient temperature To exceeds 5 [° C.], the temperature drop is assumed to be temporary, the air supply valve 8v is switched to the closed side, and the water supply valve 9 is operated at a normal temperature control. The open / close control is performed according to (steps S8, S1 to S4).

  On the other hand, if 5 ° C. or less is maintained even when the time point ta is reached, the water supply valve 9 is maintained in the closed state and the air supply valve 8v is closed. Switching is performed (steps S8 and S9). As a result, the supply of the compressed air Ap is stopped, but the watering mechanism 6 is maintained in an empty state. Therefore, reliable freezing prevention of the watering mechanism 6 including the spray nozzles Ns. Thereafter, the ambient temperature To is determined from time to time, and the closed state is maintained for both the water supply valve 9 and the air supply valve 8v as long as the state of 5 [° C.] or less is maintained. The change data of the ambient temperature To in this case is shown by a virtual line Tos in FIG. 6A, and the switching signal Vw for the water supply valve 9 is shown by a virtual line Vws in FIG. On the other hand, when the ambient temperature To exceeds 5 [° C.] thereafter, the air supply valve 8v is maintained on the closed side, but the water supply valve 9 is controlled to open and close according to normal temperature control (step S8, S1-S4).

  Therefore, according to the antifreezing device 1 according to this embodiment, when there is a possibility of freezing, the compressed air Ap supplied from the supply source 100 is supplied to the watering mechanism 6 by the compressed air supply control function. In order to supply, the water Lwm remaining inside can be forcibly discharged from the spray nozzles Ns. As a result, freezing of the watering mechanism 6 including the spray nozzles Ns... During the cold season can be reliably prevented, and the utilization rate of the watering mechanism 6 can be increased. The original ability of the free cooling chiller U can always be exhibited.

  On the other hand, the freeze prevention device 1 according to the present embodiment also includes a freeze prevention measure in the outside air cooling system M2. Hereinafter, antifreezing measures in the outside air cooling system M2 will be described.

  First, as shown in FIG. 2, the connection port 7 described above is connected to and communicated with the upper end of the outside air heat exchanger 5 through a second air supply valve 12 v that supplies or stops the compressed air Ap. Thereby, the air supply second circuit 12 is configured. An electromagnetic opening / closing valve can be used as the second air supply valve 12v. If such an air supply second circuit 12 is provided, the compressed air Ap can be supplied also to the outside air heat exchanger 5, so that the outside air heat exchange is performed even when the free cooling chiller U is stopped or in operation. When the cooler 5 is not in use, the compressed air Ap is supplied to the outside air heat exchanger 5 so that the cooling water Lw remaining inside the outside air heat exchanger 5 can be forcibly removed. There is an advantage that effective freezing prevention for the exchanger 5 and further the outside air cooling system M2 can be achieved.

  Further, the air supply second circuit 12 has one end side of the air release valve 13v connected to and communicated with the downstream side of the second air supply valve 12v, and the other end side exposed to the atmosphere. Is provided. In this case, an electromagnetic on-off valve can be used as the air vent valve 13v. Thereby, the air supply second circuit 12 can be opened to the atmosphere or blocked from the atmosphere. At this time, the other end side (downstream side) of the air vent valve 13 v is exposed to the atmosphere inside the coolant tank 14. If such an air vent circuit 13 is provided, even if the compressed air Ap is not used because there is no supply source of the compressed air Ap at the place where the free cooling chiller U is installed, the remaining cooling water Lw Can be extracted by natural fall. Further, since the downstream side of the air vent valve 13v is exposed to the atmosphere inside the coolant tank 14, the air vent valve 13v vents the cooling water Lw when the remaining cooling water Lw is withdrawn, so that the cooling water Lw is cooled with the coolant. During the re-supplying process in which the cooling air Lw can be smoothly returned to the tank 14 and the cooling air Lw is again filled in the air vent circuit 13 from which the cooling water Lw has been extracted, the internal air and the cooling water Lw are allowed to escape to the inside of the coolant tank 14. Therefore, a quick resupply process can be performed.

  On the other hand, as shown in FIG. 2, a heater 16 indicated by an imaginary line can be provided inside the coolant tank 14 if necessary. The heater 16 is particularly designed for cold regions and is positioned as an optional part. The heater 16 can heat the coolant Lw stored in the coolant tank 14. In this way, if the coolant tank 14 is provided with the heater 16 for heating the coolant Lw stored therein, the ambient temperature may be greatly reduced, etc., and there is a risk of freezing the entire coolant Lw. Even if it exists, there exists an advantage which can prevent the freezing of the cooling water Lw reliably by warming the cooling water Lw stored by the coolant tank 14 with the heater 16, and also circulating with the circulation pump of the external air cooling system M2. As shown in FIG. 3, the second air supply valve 12 v, the air vent valve 13 v and the heater 16 are connected to the output port of the controller main body 52.

  Such anti-freezing measures can prevent the outside air cooling system M2 from being frozen by two anti-freezing modes, that is, the sampling anti-freezing mode D1 and the circulation anti-freezing mode D2. In this case, the extraction freezing prevention mode D1 extracts all the cooling water Lw remaining in the outdoor air heat exchanger 5 when the operation of the free cooling chiller U is stopped or when the outdoor air heat exchanger 5 is not in use. Therefore, the anti-freezing mode is a mode in which the anti-freezing mode is a mode in which when the operation of the free cooling chiller U is stopped, the circulating pump 24 is operated to circulate the cooling water Lw. In this circulation freezing prevention mode, the heater 16 described above is used as necessary.

  FIG. 7 shows a correspondence table of the two freeze prevention modes used for the minimum ambient temperature Td. As is apparent from the correspondence table, when the assumed minimum ambient temperature Td is 5 [° C.] <Td, the sampling freeze prevention mode D1 is used. In this case, water (cooling water Lw) can be used without using antifreeze as the cooling liquid L, and the use of the heater 16 and the compressed air Ap is optional. If the minimum ambient temperature Td is −10 [° C.] <Td ≦ 5 [° C.], it is possible to select the use of the sampling freeze prevention mode D1 or the circulation freeze prevention mode D2. At this time, when water is used as the cooling liquid L, it is assumed that the circulation freezing prevention mode D2 is selected, and the use of the heater 16 and the compressed air Ap is indispensable. Selection of the prevention mode D1 is a premise, and the use of the compressed air Ap is optional, but the use of the heater 16 is essential. Furthermore, if the minimum ambient temperature Td is −20 [° C.] <Td ≦ −10 [° C.], it is essential to use an antifreeze liquid as the cooling liquid L, and the circulation freezing prevention mode D2 is selected. At this time, the use of the compressed air Ap is optional, but the use of the heater 16 is essential.

  In the illustrated case, the circulation freezing prevention mode D2 is executed when the operation of the free cooling chiller U is stopped (or when the underload is stopped) and the ambient temperature To is To ≦ 5 [° C.] When the circulation freeze prevention mode D2 is being executed, the execution stops when To> 7 [° C.]. In the illustrated example, the heater 16 is turned on when the return liquid temperature Tr becomes Tr <10 [° C.] during the execution of the circulation freeze prevention mode D2, and the heater 16 is turned on while the heater 16 is in use. Turns OFF when> 15 [° C].

  FIG. 8 is a timing chart of signals at various parts when the sampling / freezing prevention mode D1 is executed. In FIG. 8, if the free cooling chiller U is stopped at the time t1, or if the use of the outside air heat exchanger 5 is stopped even during operation, first, the main sampling operation, that is, Then, the second air supply valve 12v is switched to the open side, and the second air supply valve 12v is controlled to be closed when the first set time Z1 (for example, 5 [seconds]) has elapsed. As a result, the compressed air Ap is supplied to the inside from the upper end of the outside air heat exchanger 5 (5p, 5q), and the cooling water Lw remaining inside is forcibly pushed out by the compressed air Ap and the extruded cooling water Lw. Flows into the coolant tank 14.

  Next, the complementary sampling operation is performed several times (illustrated three times in the example). In this complementary extraction operation, when the main extraction operation is completed, the air extraction valve 13v is opened for the second set time Z2 (illustrated 10 [minutes]) at the timing when the second air supply valve 12v is switched to the closed side. When the second set time Z2 elapses, the air vent valve 13v is switched to the closed side. Further, at this timing, the operation in which the second air supply valve 12v is switched to the open side for the third set time Z3 (illustrated for 1 [second]) is the fourth set time Z4 (illustrated for 1 [second]). Every other three times, the above operation is repeated three times. As described above, a reliable anti-freezing measure for the outside air cooling system M2 is achieved.

  Next, a modified example of the air supply valve 8v and the discharge switching valve 11 of the freeze prevention device 1 according to the present embodiment, and a modified embodiment of the free cooling chiller U will be described with reference to FIGS.

  FIG. 9 shows a modified example of the air supply valve 8 v and the discharge switching valve 11, that is, an integrated three-way switching valve 91. Although the air supply valve 8v and the discharge switching valve 11 in FIG. 2 described above are configured using two independent electromagnetic on-off valves, FIG. 9 also functions as both the air supply valve 8v and the discharge switching valve 11. A single three-way switching valve 91 is used. If the three-way switching valve 91 is switched to the position shown in FIG. 9A, the state is the same as when the air supply valve 8v is switched to the closed side and the discharge switching valve 11 is switched to the closed side. Further, switching to the position of FIG. 9B is the same as the state in which the air supply valve 8v is switched to the open side and the discharge switching valve 11 is switched to the closed side. Further, switching to the position shown in FIG. 9C is the same as the state in which the air supply valve 8v is switched to the closed side and the discharge switching valve 11 is switched to the open side.

  On the other hand, FIG. 10 shows a modified embodiment of the free cooling chiller U. The above-described free cooling chiller U shown in FIGS. 1 to 5 shows the case where the outside air heat exchanger 5 (condenser 18) disposed in the outside air heat exchange chamber Rc is configured in a V shape. In the modified embodiment shown, the outside air heat exchanger 5 is combined with heat exchange units 5p, 5q, 5r, and 5s each having a pair of plan views formed in a U shape, thereby forming the plan view in an X shape. The blower fan 4 was disposed above the outside air heat exchanger 5 and at a downstream position in the blower direction Fw. In this case, the condenser 18 is constituted by two condensing units 18x and 18y bent in a U-shape, and the central mountain folds of the condensing units 18x and 18y are opposed to each other so that the plan view becomes X-shaped. Arranged. Accordingly, each of the condensing units 18x and 18y is the same as the condensing unit portion 18p described above in that a large number of heat dissipating fins are attached to the outer peripheral surface of the refrigerant tube unit in which the refrigerant tube through which the refrigerant passes is formed in a zigzag shape. However, it is different in that it is formed in a dogleg shape by bending the center of the refrigerant pipe unit. In addition, each heat exchange unit 5p is arranged so as to face both sides of the mountain folds in the two condensing units 18x and 18y, and upstream of the air blowing direction Fw of the blower fan 4 with respect to each condensing unit 18x. Arrange to the side.

  Thereby, the two spaces Spq and Srs in the positional relationship facing each other in the four spaces Spq, Sqr, Srs, and Ssp partitioned by the four heat exchange units 5p. For this reason, intake ports 21i..., 21i... Into which the outside air A flows are respectively provided on the left and right sides and the upper side of the casing 21 facing the spaces Spq and Srs. On the other hand, the remaining two spaces Sqr and Ssp are on the air outlet side with respect to the spaces Spq and Srs. Therefore, a guide plate (not shown) is disposed between the blower fan 4 and the two spaces Sqr and Ssp, and the two spaces Sqr and Ssp are sucked by the blower fan 4. Further, one spray nozzle Ns is disposed in each of the spaces Spq and Srs. This spray nozzle Ns has a wide spray angle, and can spray the two heat exchange units 5p, 5q (or 5r, 5s) from one spray nozzle Ns. In addition, in FIG.9 and FIG.10, the same code | symbol is attached | subjected to the same part as FIGS. 1-5, and the structure was clarified.

  As described above, the free cooling chiller U according to the present invention may be configured to have a V-shaped side view by combining the outside air heat exchanger 5 with a pair of flat heat exchange units 5p and 5q. In addition, various combinations of the outdoor air heat exchanger 5 are possible, for example, the plan view may be formed into an X shape by combining the heat exchange units 5p, 5q, 5r, and 5s formed in a pair of plan views. Even if it is configured in a form, it can be applied and is excellent in adaptability and versatility.

  The preferred embodiment (modified embodiment) has been described in detail above. However, the present invention is not limited to such an embodiment, and the present invention is not limited to the detailed configuration, shape, material, quantity, control method, and the like. Changes, additions and deletions can be made arbitrarily without departing from the scope of the invention. For example, in the embodiment, as an example of the configuration of the outdoor air heat exchanger 5, the V-type and the X-type are given. However, one or two heat exchange units 5p and 5q that are the most general configurations are arranged in parallel. It does not exclude standing configurations. Moreover, although the case where heat exchange unit 5p ... is arrange | positioned by superimposing or adjoining to the condensation unit 18p ... was shown, the case where it arrange | positions apart is not excluded. Furthermore, the supply source 100 of the compressed air Ap is a mode in which it is desirable to use an existing supply source for the facility where the free cooling chiller U is installed, but this does not exclude a dedicated supply source. The cooling liquid L includes various kinds of solutions including the cooling water Lw and antifreeze, and the cooling water Lw includes various types of fresh water such as tap water and well water.

  The anti-freezing device according to the present invention can be used for various cooling chillers that are used by being connected to various parts to be cooled such as machine tools that need to be cooled by circulating a coolant.

  1: anti-freezing device, 3: cooling device, 4: blower fan, 5 (5p, 5q): outside air heat exchanger, 6: sprinkling mechanism, 7: connection port, 8: air supply circuit, 8v: air supply valve, 9: Water supply valve, 11: Discharge switching valve, 12: Air supply second circuit, 12v: Second air supply valve, 13: Air vent circuit, 13v: Air vent valve, 14: Coolant tank, 15: Coolant circulation circuit , 16: heater, 100: supply source, U: free cooling chiller, L: coolant, M1: internal cooling system, M2: outside air cooling system, Mc: control system, A: outside air, Ap: compressed air, Fw: air blowing Direction, Ns ...: Spray nozzle, To: Ambient temperature, Zs: Set time

Claims (8)

  An internal cooling system using a cooling device for cooling the cooling liquid, an external air cooling system having an external air heat exchanger for exchanging heat between the external air blown by the blower fan and the cooling liquid, the internal cooling system and the external air cooling system A control system that controls the cooling of the cooling liquid using the air and an upstream position of the outside air heat exchanger in the blowing direction of the outside air so that water can be sprayed on the outside air heat exchanger An anti-freezing device for a free cooling chiller having a watering mechanism having a spray nozzle, a connection port to which a compressed air supply source can be connected, and an air supply valve for supplying or stopping the compressed air to the connection port The air supply circuit connected to at least the downstream side of the water supply valve that supplies or stops water to the spray nozzle, and at least when the ambient temperature exceeds the set temperature, the air supply valve is closed. ~ side Switching and controlling opening and closing of the water supply valve, and when the ambient temperature is lower than the set temperature, the water supply valve is switched to the closed side, and the air supply valve is switched to the open side for a set time and then switched to the closed side. A free cooling chiller anti-freezing device comprising a control system having a compressed air supply control function.   2. The free cooling chiller anti-freezing device according to claim 1, wherein the compressed air supply source is an existing supply source for equipment in a place where the free cooling chiller is installed.   The air supply circuit includes a discharge switching valve capable of discharging water remaining between the spray nozzle and the air supply valve (or the water supply valve) to the outside by connecting to the downstream side of the water supply valve. The freezing chiller anti-freezing device for a free cooling chiller according to claim 1 or 2.   The free cooling chiller anti-freezing device according to claim 3, wherein the discharge switching valve has a downstream side connected to a coolant tank.   The air supply circuit includes an air supply second circuit in which the connection port is connected to an upper end of the outside air heat exchanger via a second air supply valve that supplies or stops compressed air. The freezing prevention apparatus of the free cooling chiller in any one of Claims 1-4.   6. The free cooling chiller according to claim 5, wherein the second air supply circuit includes an air vent circuit having an air vent valve connected to a downstream side of the second air supply valve to open or shut off the atmosphere. Anti-freezing device.   The outside air cooling system includes a coolant circulation circuit for circulating the coolant stored in the coolant tank to the outside air heat exchanger, and the downstream side of the air vent valve is exposed to the atmosphere inside the coolant tank. The freezing chiller anti-freezing device according to any one of claims 1 to 6.   8. The free cooling chiller anti-freezing device according to claim 7, wherein the coolant tank includes a heater for heating the coolant stored therein.

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