JP5906448B2 - Cooling system and solvent recovery system using the same - Google Patents

Description

  The present invention relates to a cooling system using a cooling tower and a solvent recovery system using the same. In particular, the water temperature supplied to the cooler can be kept constant with high accuracy, and even if conditions such as the temperature and humidity of the outside air change, it is possible to send cooling water at a stable temperature to the cooler. The present invention relates to a cooling system that can be set in detail and a solvent recovery system using the same.

  Many cooling systems using cooling towers have been proposed. For example, Patent Document 1 discloses a system in which a plurality of (four) cooling towers are arranged to supply cooling water to a refrigerator with respect to a heat load. Here, it aims at stabilizing the supply temperature of cold water. Therefore, a temperature sensor is provided in a supply pipe that supplies cold water from each cooling tower so that the number of rotations of the fans of each cooling tower can be adjusted to two stages. Then, the load fluctuation rate is detected from the temperature of the cold water returning to the refrigerator, and the number of rotations of the cooling tower fan is calculated from the load fluctuation rate, the temperature of the cooling water by the temperature sensor, and the change temperature. Is to decide.

  Further, Patent Document 2 aims to achieve energy saving by performing a so-called free cooling operation for a heat exchanger of an indoor unit using cooling water from a cooling tower. Here, a refrigerator and a cooling tower are prepared, and usually the cooling tower and the refrigerator operate. In this system, the outside air temperature is measured, and when the outside air temperature reaches a predetermined temperature, the refrigerator is stopped and the operation is switched to the operation of only the cooling tower. Therefore, energy saving can be achieved by stopping the refrigerator by the outside air temperature.

JP-A-10-009796 Japanese Patent Application Laid-Open No. 07-019523

  In patent document 1, the fluctuation | variation of a thermal load is detected and the operation | movement of a cooling tower is switched according to the fluctuation | variation. However, no change in the temperature and humidity of the outside air is detected. Therefore, no control is performed until the temperature of the supplied cooling water changes. However, even if the operating condition of the cooling tower is changed after the temperature of the supplied cooling water has changed, the cooling water itself does not cool immediately. That is, a time lag occurs when the water temperature falls. As a result, it is difficult to provide cooling water with a stable water temperature.

  This is because the temperature of the cooling water supplied to the refrigerator is controlled by operating the cooling tower. In other words, direct control of the water temperature with a cooling tower having a large heat capacity requires a large number of cooling towers. That is, there is a problem that the cost is increased.

  In addition, since the cooling tower is affected by the outside air conditions such as temperature and humidity, in a configuration where it is impossible to grasp how much the outside air is cooling and the current operation is being performed, Cooling water at a predetermined temperature cannot be supplied quickly according to the change.

  Patent Document 2 determines whether or not to use a refrigerator according to the outside air temperature. Therefore, it is recognized as having a certain effect. However, there is no consideration regarding the point of further energy saving when only the cooling tower is operated. In other words, nothing is disclosed about a device for further reducing the power consumption when the free cooling can be performed.

  The present invention has been conceived in view of the above problems, and most fundamentally, stably maintains the cooling water supplied from the cooling tower to the heat load at a predetermined temperature. Furthermore, the present invention provides a cooling system that enables further energy saving while maintaining the temperature of the cooling water to be supplied extremely stably.

More specifically, the cooling system of the present invention includes:
A cooler for cooling the cooled object with cooling water;
A circulation unit that supplies the cooling water to the cooler and cools the cooled cooling water again;
An outside air wet bulb temperature sensor for detecting the outside air wet bulb temperature;
A temperature sensor disposed in the circulation unit, and a controller for controlling a valve, an inverter, and a circulation pump in the circulation unit, connected to a temperature sensor disposed in the circulation unit and the outside air wet bulb temperature sensor;
The circulation unit is
A cooling tower having a fan whose rotation is controlled by the inverter and recooling the cooled cooling water;
A water supply pipe for sending the cooling water whose temperature is lowered in the cooling tower to the cooler;
A return pipe that returns cooling water after depriving heat from the cooler to the cooling tower from the cooler;
A bypass pipe communicating between the water supply pipe and the return pipe;
Said circulation pump disposed between said water supply pipe and communicating point between the cooler of the bypass pipe,
A bypass valve provided in the bypass pipe;
A throttle valve provided between a communication point of the return pipe and the bypass pipe and the cooling tower;
An outlet water temperature sensor provided at the outlet of the cooling tower;
A supply water temperature sensor provided between a communication point of the water supply pipe and the bypass pipe and the circulation pump;
The controller is
The detection value of the supply water temperature sensor becomes a predetermined value for the bypass valve, the throttle valve, the inverter, and the circulation pump according to the detection values of the outside air wet bulb temperature sensor, the outlet water temperature sensor, and the supply water temperature sensor. To control and
The circulation unit further includes
An external cooling water supply pipe communicated between a communication point of the water supply pipe and the bypass pipe and the cooling tower;
An external cooling water return pipe communicated between a communication point of the return pipe and the bypass pipe and the cooling tower;
A first valve provided in the external cooling water supply pipe;
A communication point between the water supply pipe and the external cooling water supply pipe; a second valve provided between the cooling towers;
A communication point between the return pipe and the external cooling water return pipe; and a third valve provided between the cooling towers;
A fourth valve provided on the external cooling water return pipe,
The control device further controls the first to fourth valves when receiving an external free cooling enabling signal, which is a signal that cooling water from the outside can be used, from the external cooling water supply pipe. The cooling water is supplied to the cooler .

Moreover, the cooling system of the present invention may connect a plurality of the above cooling systems in series, specifically,
A second cooler is provided after the cooler;
A second circulation unit having a refrigerator for supplying secondary side cooling water to the second cooler and cooling the cooled secondary side cooling water again;
The control device is further connected to a temperature sensor disposed in the second circulation unit, a valve, an inverter, a circulation pump, and the refrigerator.
The second circulation unit is
A second cooling tower having a fan whose rotation is controlled by a second inverter and recooling the primary side cooling water supplied to the refrigerator;
A second water supply pipe for sending the primary side cooling water whose temperature has been lowered in the second cooling tower to the refrigerator;
A second return pipe that returns primary side cooling water after depriving heat from the refrigerator to the second cooling tower from the refrigerator;
A second bypass pipe communicating between the second water supply pipe and the second return pipe;
A second circulation pump disposed between a communication point of the second water supply pipe and the second bypass pipe and the refrigerator;
A second bypass valve provided in the second bypass pipe;
A second throttle valve provided between a communication point of the second return pipe and the second bypass pipe and the second cooling tower;
A second outlet water temperature sensor provided at the outlet of the second cooling tower;
A second supply water temperature sensor provided between a communication point of the second water supply pipe and the second bypass pipe and the second circulation pump;
A return water temperature sensor disposed between a communication point of the second return pipe and the second bypass pipe and the refrigerator;
The controller is
The second bypass valve, the second throttle valve, and the second valve according to detection values of the outside air wet bulb temperature sensor, the second outlet water temperature sensor, the second supply water temperature sensor, and the return water temperature sensor. The inverter, the second circulation pump, and the refrigerator are controlled so that the detected value of the supply water temperature sensor becomes a predetermined value.

In addition, the above cooling system can be used for a solvent recovery device, specifically,
A solvent source that generates hot solvent-containing air;
A first gas cooler that cools the solvent-containing air and condenses and recovers the solvent in the solvent-containing air;
A second gas cooler that further cools the solvent-containing air that has passed through the first gas cooler and condenses and recovers the solvent in the solvent-containing air; and
A demister that recovers a mist component from the solvent-containing air that has passed through the second gas cooler;
An adsorption / desorption rotor that removes the solvent from the solvent-containing air that has passed through the demister and discharges the regenerated air;
A drain pipe for recovering the solvent in the solvent-containing air recovered from the first gas cooler, the second gas cooler, and the demister;
A solvent recovery system for cooling the first gas cooler and the second gas cooler by the circulation unit and the second circulation unit in the cooling system, respectively.

  The cooling system of the present invention includes a water supply pipe that sends cooling water from the cooling tower to the cooler and a bypass pipe that communicates between the return pipe that returns from the cooler, and adjusts the flow rate of the bypass pipe and the return pipe. Therefore, the cooling water cooled by the cooling tower and the cooling water that has been heat-converted by the cooler are mixed and supplied to the cooler, so that even if the supplied water temperature changes, the cooled cooling water and By adjusting the mixing ratio of the warm cooling water, it is possible to make the temperature of the cooling water supplied at a speed almost instantaneously constant.

  Moreover, since it has an outside air wet bulb temperature sensor, it can grasp | ascertain the present driving | running state with respect to the cooling capacity of outside air. Therefore, when the cooling capacity of the outside air is high, the cooling tower can be operated with reduced cooling power, and energy saving can be realized.

The figure which shows the basic composition of the cooling system of this invention Diagram explaining the relationship between the cooling tower outlet water temperature and fan rotation speed A diagram showing the relationship between outdoor wet bulb temperature and approach temperature Diagram showing the relationship between rated cooling capacity ratio Q and inverter power consumption The figure which shows the flow of the control apparatus 22 The figure which shows the basic composition of the other cooling system of this invention. The figure which shows the basic composition of the other cooling system of this invention. A diagram showing a cooling system having a plurality of circulation units The figure which shows the structure of the cooling system which has a refrigerator The figure explaining the state for estimating power consumption when it has a refrigerator The figure which shows the structure of the other cooling system which has a refrigerator. The figure which shows the structure of the solvent collection | recovery system which has a cooling system of this invention

  Hereinafter, the cooling system of the present invention and a solvent recovery system using the same will be described. First, the most basic configuration of the present invention will be described in this embodiment.

(Embodiment 1)
FIG. 1 shows the configuration of the cooling system of the present invention. The cooling system 1 of the present invention includes a cooler 10 serving as a heat load, a circulation unit 11 that cools cooling water serving as a heat medium for cooling the cooler 10, and a control device 22 that controls the operation of the circulation unit 11. And an outside air wet bulb temperature sensor 24.

  The cooler 10 serving as a heat load is not particularly limited, but is preferably designed so as to constantly exchange a predetermined amount of heat. For example, a refrigerator may be used, and in a solvent recovery system described later, a gas cooler for cooling a gas containing a solvent can be suitably used.

  The outdoor wet bulb temperature sensor 24 is a sensor that measures the temperature of a dry bulb that is in contact with a nonwoven fabric wet with water. The configuration is not limited to this as long as the temperature at which moisture is evaporated can be measured. The outside wet bulb temperature sensor 24 can estimate the amount of water evaporation in the environment where the circulation unit 11 is currently placed. The output of the outside wet bulb temperature sensor 24 is connected to the control device 22.

  The circulation unit 11 cools the cooling tower 30 having a fan that is rotated by the inverter 31, the water supply pipe 32 that sends the cooling water from the cooling tower 30 to the cooler 10, and the cooling water that is heat-exchanged by the cooler 10 and whose water temperature is increased. The return pipe 34 returning to the tower 30 constitutes a circulation system. In the cooling system of the present invention, a bypass pipe 36 that communicates between the water supply pipe 32 and the return pipe 34 is disposed. Here, the communication point between the water supply pipe 32 and the bypass pipe 36 is defined as a water supply side communication point 41, and the communication point between the return pipe 34 and the bypass pipe 36 is defined as a return side communication point 42.

  The cooling tower 30 has a configuration in which the cooling water returned from the cooler 10 through the return pipe 34 is dropped from above, and the cooling water is cooled by contact with air or by heat of vaporization of a part of the cooling water. Moreover, in order to promote the contact with air when falling from the upper part, it is assumed that the fan can ventilate. This fan is driven by an inverter 31.

  The bypass pipe 37 is provided with a bypass valve 37 capable of adjusting the flow rate. Further, a throttle valve 35 capable of adjusting the flow rate is disposed in the vicinity of the cooling tower 30 of the return pipe 34. The throttle valve 35 is disposed between the return side communication point 42 and the cooling tower 30.

  An outlet water temperature sensor 38 is disposed near the outlet of the cooling tower 30 in the water supply pipe 32. A supply water temperature sensor 39 is disposed between the water supply side communication point 41 and the cooler 10. A circulation pump 40 is disposed between the supply water temperature sensor 39 and the cooler 10. These temperature sensors (38, 39), flow rate adjusting valves (37, 35), and circulation pump 40 are electrically connected to the control device 22.

  Therefore, the control device 22 receives signals relating to conditions from the temperature sensors (38, 39), the flow rate adjusting valves (37, 35), the circulation pump 40, the inverter 31, and the outside wet bulb temperature sensor 24. In addition, the operation of the circulation unit 11 can be controlled by sending an instruction signal for changing the state of each device.

  Moreover, the circulation unit 11 can also be provided with a plurality of water stop valves as in the embodiments described later. The control device 22 can also open and close these stop valves. Therefore, it can be said that the control device 22 controls the valves (flow rate adjustment valve and water stop valve), the inverter, and the circulation pump in the circulation unit 11.

  Next, the flow of cooling water in the cooling system 1 of the present invention will be described. With reference to FIG. 1, the cooling water Wc passes from the cooling tower 30 through the water supply pipe 32, passes through the water supply side communication point 41, and is sent to the cooler 10. In the cooler 10, heat conversion is performed, and the cooling water Wh has a higher temperature than before entering the cooler 10, and flows through the return pipe 34 toward the cooling tower 30. It is the circulation pump 40 that creates this water flow.

  By adjusting the bypass valve 37 and the throttle valve 35 in this flow path, a part of the cooling water Wh can be returned to the water supply pipe 32 through the bypass pipe 36. That is, the cooling water Wh is mixed with the cooling water Wc at the water supply side communication point 41. That is, the cooling water supplied to the cooler 10 is a mixture of the cooling water Wc and the cooling water Wh. Therefore, the cooling water supplied to the cooler 10 is referred to as cooling water Wm. The cooling water Wc flowing through the water supply pipe 32 from the cooling tower 30 becomes the cooling water Wm after passing the water supply side communication point 41. The water temperature of the cooling water Wm can be obtained by the supply water temperature sensor 39.

  The mixing ratio of the cooling water Wc and the cooling water Wh at the water supply side communication point 41 can be controlled between the case where all the cooling water Wc is used and the case where all the cooling water Wh is used. That is, if the bypass valve 37 is fully closed and the throttle valve 35 is fully opened, all the cooling water Wm becomes the cooling water Wc. Further, if the bypass valve 37 is fully opened and the throttle valve 35 is fully closed, all the cooling water Wm becomes the cooling water Wh.

  Here, the cooling water Wh is at a higher temperature than the cooling water Wc. Therefore, the cooling water Wm can be set to a temperature between the water temperature of the cooling water Wc and the water temperature of the cooling water Wm. In addition, the temperature of the cooling water Wm can be adjusted in a time that can be said to be instantaneous by adjusting the flow rates of the bypass valve 37 and the throttle valve 35.

  That is, when the water temperature of the cooling water Wm supplied to the cooler 10 by the supply water temperature sensor 39 deviates from a predetermined set value, the control device 22 that knows the “deviation” causes the bypass valve 37 and the throttle valve 35 ( In some cases, the circulation pump 40 can be adjusted to immediately return to a predetermined water temperature. This “deviation” is because the supply water temperature sensor 39 detects the water temperature of the cooling water Wm, and the control device 22 knows in advance a predetermined set value (a target value of the water temperature of the supplied cooling water).

  Therefore, in the cooling system of the present invention, when the temperature of the cooling water supplied to the cooler 10 changes as in the prior art, the temperature of the cooling water is corrected by correcting the operation itself (fan rotation speed) of the cooling tower 30. Is not adjusting. That is, the cooling water Wm having a very stable water temperature can be supplied to the cooler 10.

  The method using the bypass pipe 36 as described above uses the cooling water Wc supplied from the cooling tower 30 whose cooling capacity depends on the outside air state (hereinafter referred to as “outside air state”) such as temperature and humidity. Therefore, the cooling system 1 is very advantageous in order to supply the cooling device 10 with the stable cooling water Wm.

  This will be described below. The cooling tower 30 is a heat exchanger that takes heat from the cooling water Wh returned from the cooler 10 through the return pipe 34 and converts it into the cooling water Wc. Here, the cooling tower 30 is installed outdoors and cools the cooling water Wh using outside air. Therefore, the water temperature of the obtained cooling water Wc varies depending on the outside air state. For example, since the outside air state usually varies depending on the time of day, the water temperature of the cooling water Wc changes according to the change in the outside air state from morning to noon, from day to evening, and from evening to night. It also varies with humidity.

  However, if the method uses the bypass pipe 36 as described above, the temperature of the cooling water Wc supplied to the water supply side communication point 41 changes, and the supply water temperature to the cooler 10 (value of the supply water temperature sensor 39). Even if changes, the control device 22 adjusts the bypass valve 37 and the throttle valve 35 (in some cases, the circulation pump 40), so that it can be immediately returned to a predetermined water temperature. Therefore, the water temperature of the cooling water Wm supplied to the cooler 10 is stabilized. Note that the target value of the supply water temperature is given in advance as a supply water temperature set value (TDSSP).

  In other words, the control device 22 controls the detected value TDPV1 (exit water temperature measured value) of the outlet water temperature sensor 38 and the detected value TDPV2 (supply water temperature) of the supply water temperature sensor 39. It can be said that the bypass valve 37 (MV1) and the throttle valve 35 (MV2) are controlled so that the supply water temperature becomes a predetermined value (supply water temperature set value TDSSP).

  Furthermore, the cooling system 1 of the present invention having the above-described configuration can reduce power consumption by performing the operation described below.

  As is well known, in the case of cooling using outside air, the cooling water Wc cannot be cooled to a temperature lower than the outside air wet bulb temperature. In practice, the temperature of the cooling water Wc can be lowered only to a temperature about 5 ° C. higher than the outside wet bulb temperature due to various losses. Further, when the temperature of the outside air wet bulb is high to some extent, the cooling water Wh is not sufficiently cooled only by being dropped from the upper part of the cooling tower 30, and in order to forcibly contact the outside air, the fan is turned to apply wind. .

  Conventionally, with regard to the operation of the fan, the operation state of the fan is controlled from the water temperature on the cooler 10 side or the like. However, the water temperature of the cooling water Wc depends on the outside air state. Therefore, in the conventionally known fan operation method, whether the fan is rotating in a state where the water temperature of the cooling water Wc can be lowered in consideration of the current outside air state, or more than this, I did not know whether the fan was running in a state where the water temperature of Wc could not be lowered.

  The cooling system 1 of the present invention has an outside air wet bulb temperature sensor 24 and rotates the fan of the cooling tower 30 according to the value of the outside air wet bulb temperature sensor 24 and the outlet water temperature from the cooling tower 30. . That is, if the value of the outside air wet bulb temperature is sufficiently low as compared with the temperature of the cooling water Wm supplied to the cooler 10, the cooling system 1 itself is hindered even if the rotation of the fan of the cooling tower 30 is reduced or stopped. You can drive without. Since such a determination can be made, the cooling system 1 of the present invention can reduce power consumption.

  This will be described in more detail. The value of the outside wet bulb temperature sensor 24 is TOWPV, and the value of the outlet water temperature sensor 38 is TDPV1. The value of the supply water temperature sensor 39 is TDPV2. And the target set value of the outlet water temperature of the cooling tower 30 is set to TDOSP. TDOSP is, for example, a temperature 5 ° C. higher than the outdoor wet bulb temperature TOWPV. That is, TDOSP = TOWPV + 5 ° C. On the other hand, the outlet water temperature of the cooling tower 30 can be detected by the outlet water temperature sensor 38. This temperature was TDPV1 as described above. TDPV1 is the water temperature of the cooling water Wc.

  FIG. 2A shows the relationship between TDPV1, which is the outlet water temperature of the cooling tower 30, and the rotational speed (air volume) of the fan. The horizontal axis is the water temperature (TDPV1) of the cooling water Wc, and the vertical axis is the rotational speed (air volume) of the fan. The TDOSP line in FIG. 2 is a temperature 5 ° C. higher than the outside wet bulb temperature, for example, from the above description. In fact, below this, TDPV1 (water temperature of the cooling water Wc) cannot be lowered. For example, when TDPV1 and TDSOP currently match (TDPV1 in FIG. 2A), it indicates that the vehicle is being operated in a state in which TDPV1 cannot be lowered any more than the outside air state. .

  At this time, the rotational speed of the fan is preferably set to about half of the maximum rotational speed from the viewpoint of the operating point. This is because if the temperature of TDPV1 rises slightly (TDPV1 + α), the temperature of the cooling water Wc can be returned to TDPV1 again by increasing the number of rotations of the fan. Further, if the water temperature of TDPV1 is slightly lowered (TDPV1-β), power consumption can be reduced by lowering the rotational speed of the fan. Of course, the design may be performed so that the operation under the worst condition such as summer is established at about 80% of the fan rotation speed. In FIG. 2A, the line indicating the relationship between the water temperature of the cooling water Wc and the rotational speed of the fan is an operation line of the rotational speed of the fan.

  Now, in FIG. 2B, it is assumed that the outside air state has changed and TDOSP1 has decreased to TDOSP2. Since the ability to take the heat of the outside air has increased, it is assumed that the water temperature (W1) of Wc follows and decreases to W2 even if the rotational speed of the fan is decreased from R1 to R2. That is, the rotation speed of the fan decreases, and the water temperature of the cooling water Wc supplied to the water supply side communication point 41 also decreases. Of course, since the temperature of the cooling water Wm supplied to the cooler 10 is determined in advance, the opening degree of the bypass valve 37 and the throttle valve 35 is adjusted, and the mixing ratio of the cooling water Wh returned from the cooler 10 is increased. Then, the cooling water Wm is kept constant.

  At this time, if the rotational speed of the fan is further lowered (R3), the cooling capacity in the cooling tower 30 is lowered, so that the water temperature (TDPV1) of the cooling water Wc rises. The water temperature is assumed to be stable at W3. This cannot be said to have fully utilized the cooling capacity of the cooling tower 30. However, if the supply temperature of the cooling water Wm can be kept constant, even if the temperature of the cooling water Wc rises, the operation as the cooling system 1 is established, and the consumption of the fan rotation speed is reduced. Electric power can be reduced. In addition, it implement | achieves by changing TDOS which is the target value of the temperature (TDPV1) of the cooling water Wc from the cooling tower 30 in order to make it above. This corresponds to shifting the operation line of the rotational speed of the fan as indicated by the dotted line in FIG.

  In other words, the control device 22 controls the fan rotation speed (inverter 31) as described above, the cooling tower outlet water temperature target value TDOSP calculated from the detected value of the outdoor wet bulb temperature sensor 24, and the outlet water temperature sensor 38. It can be said that the inverter 31 (the number of rotations of the fan) provided in the cooling tower 30 is controlled according to the deviation from the detected value TDPV1 (actual measured value of the outlet water temperature).

  On the other hand, when the rotational speed of the fan was reduced, the temperature of the cooling water Wc increased. Therefore, at the water supply side communication point 41, the ratio of the cooling water Wh from the return pipe 34 is reduced. However, if the predetermined cooling water Wm cannot be obtained by itself, the rotational speed of the circulation pump 40 is increased, The flow rate of the cooling water must be increased. That is, the rotational speed of the fan of the cooling tower 30 and the rotational speed (flow rate) of the circulation pump 40 have a contradictory relationship.

  That is, when supplying the predetermined cooling water Wm, the rotational speed of the fan is decreased (TDPV1 increases) and the rotational speed (flow rate) of the circulation pump 40 is increased or the rotational speed of the fan is increased (TDPV1 decreases). It is possible to select whether to reduce the rotational speed (flow rate) of the circulation pump 40. These relationships change on a case-by-case basis because they change depending on the capacity of the cooling system 1 at the time of design, the installation location, the annual climate at the installation location, and the like. However, the cooling system 1 of the present invention, which can create a condition in which the power consumption in the inverter 31 and the power consumption in the circulation pump 40 conflict, can be controlled so that the total power consumption of the entire system is minimized. It is.

  In addition, since the power consumption of the circulation pump 40 is calculated | required previously with a load and rotation speed, the control apparatus 22 can have it with the table of the power consumption with respect to the parameter | index to designate beforehand. The index here is an index of control directly performed by the control device 22 on the circulation pump, such as voltage, flow rate, pump shaft rotational speed, and the like. That is, the control device 22 can estimate the power consumption of the circulation pump 40 based on the instruction transmitted to the circulation pump 40. This is called the estimated power consumption Wp of the circulation pump 40.

  On the other hand, it is not easy to estimate the power consumption in the inverter 31. However, since the cooling system 1 of the present invention has the outdoor air wet bulb temperature sensor 24, the power consumption of the inverter 31 that controls the rotational speed of the fan can be obtained without a special device. Next, this point will be described.

  FIG. 3 is a diagram showing the relationship between the outdoor wet bulb temperature TOWPV and the approach temperature ΔT1. Here, the water temperature of the cooling water Wh from the return pipe 34 returned to the cooling tower 30 is water having a water temperature designed in advance. The approach temperature ΔT1 refers to the difference between the outdoor wet bulb temperature TOWPV and the outlet water temperature TDPV1 of the cooling tower 30. In general, ΔT1 = TDPV1−TOWPV.

  In FIG. 3, the horizontal axis represents the outdoor wet bulb temperature TOWPV, and the vertical axis represents the approach temperature ΔT1. Since the outlet water temperature TDPV1 of the cooling tower 30 is not physically lower than the outside air wet bulb temperature TOWPV, there is always a relationship of TDPV1 ≧ TOWPV. That is, ΔT1 always takes a positive value.

  FIG. 3 is also a performance characteristic of the cooling tower 30. That is, it shows the ability to reduce the water temperature TDPV1 of the cooling water Wc by changing the outside wet bulb temperature TOWPV during a certain operation state (for example, rated operation state). For example, it is assumed that the current outdoor wet bulb temperature TOWPV is TW1 ° C. At this time, if the rated operation is performed, the approach temperature ΔT1 can be set to ΔT1a ° C.

  That is, the outlet water temperature TDPV1 of the cooling tower 30 can be set to (TW1 + ΔT1a) ° C. In this way, when the water temperature returning to the cooling tower 30 is determined, the relationship between the outdoor wet bulb temperature and the approach temperature during rated operation should be obtained in advance as the performance characteristics of the cooling tower 30. Can do. In FIG. 3, the line RR is a line representing the rated operation. This is also called a rated operation line RR.

  It is assumed that the current approach temperature ΔT1 is ΔT1b ° C. assuming that the above relationship is known in advance. It is assumed that the outside air wet bulb temperature TW1 ° C. is the same. This can be obtained by subtracting the outside air wet bulb temperature TOWPV (in this case, TW1 ° C.) from the temperature TDPV1 of the outlet water temperature of the cooling tower 30.

  If ΔT1b is higher than ΔT1a, it means that the cooling tower 30 is not cooled much, so the power consumption in the cooling tower 30 should be less than the rated operation state. On the other hand, if the approach temperature ΔT1 is ΔT1c which is lower than the ΔT1a which is the approach temperature at the rated operation, the outlet water temperature is lower than that at the rated operation, so the cooling is performed more than the rated operation (the power consumption is lower). Big).

  In other words, if the table already has a value indicating how much the approach temperature ΔT1 is different from the rated operation state at each outdoor wet bulb temperature, the current operation state from the approach temperature ΔT1. And the rated operating state ratio (rated cooling capacity ratio) Q can be obtained.

  FIG. 4 shows the relationship between the rated cooling capacity ratio Q and the estimated power consumption Winv of the inverter that drives the fan. The horizontal axis is the rated cooling capacity ratio Q, and Q = 1.0 during rated operation. The vertical axis represents the estimated power consumption Winv. For example, assuming that the rated cooling capacity ratio Q is QB at the current operating point B in FIG. 3 by comparison with the rated operating state, the estimated power consumption of the inverter 31 is WB from FIG. The relationship diagram of FIG. 3 and the relationship diagram of FIG. 4 can be prepared in advance, and the control device 22 can have this relationship as a table or an approximate expression.

  That is, the control device 22 can estimate the power consumption of the inverter 31 by knowing the outdoor wet bulb temperature TOWPV and the temperature TDPV1 of the cooling water Wc. The power consumption of the inverter 31 obtained as described above from the detection value of the outdoor wet bulb temperature sensor 24 and the detection value of the outlet water temperature sensor 38 is referred to as the estimated power consumption Winv of the inverter 31.

  As described above, in the cooling system 1 of the present invention, the power consumption of the inverter 31 is estimated from the outside wet bulb temperature TOWPV and the outlet water temperature TDPV1 (Winv), and the consumption of the circulation pump 40 from the instruction to the circulation pump 40 The power is estimated (Wp). Therefore, assuming that the power consumption of the entire system is the estimated total power consumption ΣW, the relationship ΣW = Winv + Wp is established. By controlling the outlet water temperature target value TDOSP (that is, the rotational speed of the fan) and the circulation pump 40 so as to minimize this ΣW, it is possible to save power in the entire system.

  In addition, the sum total of the estimated power consumption Winv of the inverter 31 of the cooling tower 30 and the estimated power consumption Wp of the circulation pump 40 is minimized while making the water temperature (TDPV2) of the cooling water Wm actually supplied to the cooler 10 constant. It is not easy to control. Moreover, since these are estimated electric power, the comparison with actual electric power is also needed. Furthermore, it is only necessary to obtain an operation state that approximates the minimum without obtaining an accurate minimum point. Therefore, it is preferable to use a method based on multivariate analysis or a genetic algorithm.

  The above operation flow is shown in FIG. Referring to FIG. 5, when the operation of cooling system 1 is started (step S100), initial setting is performed (step S102). Here, the initial setting includes setting a target value for the water temperature of the cooling water Wm supplied to the cooler 10 and the water temperature of the cooling water Wc from the cooling tower 30. This target value is the target value (TDOSP) of TDPV1.

  Next, end determination is performed (step S104). The end determination may be determined in a predetermined period or may be based on a signal for detecting some abnormality. When the process ends (Y branch of step S104), the system is stopped (step S120).

  Next, the control device 22 obtains the value of the outside air wet bulb temperature TOWPV from the outside air wet bulb temperature sensor 24 (step S106). From here, the target temperature TDOSP of the cooling water Wc is obtained. Specifically, when the approach temperature is 5 ° C., TDOSP = TOWPV + 5 ° C. When the value of TOWPV is obtained, the circulation pump 40 is driven so as to obtain a predetermined amount of water (step S108). In FIG. 5, the number of rotations of the circulation pump is represented as Prev. When the circulation pump 40 is driven, circulation of the cooling water starts.

  Next, the inverter 31 is controlled from the temperature of the TDPV1, which is the outlet water temperature of the cooling tower 30, and the fan is rotated (step S110). This uses the relationship between the rotational speed of the fan shown in FIG. 2 and TDPV1. The outlet water temperature sensor 38 (Wc water temperature: TDPV1) and the supply water temperature sensor 39 (Wm water temperature: TDPV2) are used to adjust the opening degree of the bypass valve 37 and the throttle valve 35, so that the cooling water Wm having a predetermined water temperature. Is supplied (step S112). In FIG. 5, the bypass valve 37 is represented as MV1, and the throttle valve 35 is represented as MV2.

  When the fan of the cooling tower 30 and the circulation pump 40 are operated and the bypass valve 37 and the throttle valve 35 are controlled, the cooling system 1 enters an operating state.

  Next, the estimated power consumption Winv at the inverter 31 and the estimated power consumption Wp at the circulation pump 40 are estimated (step S114). In particular, the method described with reference to FIGS. 3 and 4 is used to estimate the estimated power consumption Winv of the inverter 31. From this, it is determined whether or not the estimated total power consumption ΣW in the cooling system 1 is the minimum (step S116). If it is determined to be minimum (Y branch in step S116), the flow returns to the end determination (step S104) and the flow is repeated.

  If the estimated total power consumption ΣW is not minimum (N branch in step S116), the target value (TDOSP) of TDPV1 and the rotational speed of the circulation pump 40 are reset (step S118). Then, the flow is returned to the end determination (step S104). Since the cooling system 1 of the present invention has the above-described configuration and operates according to the procedure shown in FIG. 5, it can always supply stable cooling water to the cooler 10 and consumes it. Power can also be minimized.

(Embodiment 2)
This embodiment shows a cooling system 2 that can cope with the case where the cooling water is supplied from the outside to the first embodiment. In facilities where a cooling system is installed, various common materials are often manufactured in-house. For example, nitrogen gas or a common solvent. As for the cooling water, if heat is required in other processes and a process for removing heat from the water is performed, the water from which heat has been removed can be cooling water used in the cooling system. When such cooling water is supplied from the outside of the cooling system, power consumption can be reduced by using the cooling water and stopping the cooling tower 30.

  In FIG. 6, the outline | summary of the cooling system 2 of this invention is shown. The cooling system 2 in the present embodiment is different from the cooling system 1 in the first embodiment in that an external cooling water supply pipe 45 is disposed between the cooling tower 30 and the water supply side communication point 41, and the external cooling water return pipe 46. Is disposed between the cooling tower 30 and the return side communication point 42. A water stop valve 47 is disposed in the external cooling water supply pipe 45. Further, a water stop valve 48 is disposed on the cooling tower 30 side from the point where the external cooling water supply pipe 45 communicates with the water supply pipe 32.

  Further, a water stop valve 49 is provided between the communication point of the external cooling water return pipe 46 and the return pipe 34 and the cooling tower 30. Further, a water stop valve 50 is provided on the external cooling water return pipe 46. These water stop valves 47 to 50 are connected to the control device 22-2 and can be opened and closed by an instruction signal from the control device 22-2. The water stop valves 47 to 50 are also referred to as a first valve, a second valve, a third valve, and a fourth valve, respectively.

  In addition, the cooling tower 30 having a fan that is rotated by the inverter 31, the water supply pipe 32 that sends the cooling water from the cooling tower 30 to the cooler 10, and the cooling water that has been heat-exchanged by the cooler 10 and whose water temperature has been raised to the cooling tower 30 The circulation unit 12 is formed including the return pipe 34, the external cooling water supply pipe 45, and the external cooling water return pipe 46.

  The control device 22-2 is the control device 22 in the first embodiment, and is electrically connected to the water stop valve, so that the external free cooling possible signal Fw can be received from an external cooling water supply source. It is configured. This is because the cooling system 2 itself cannot know whether or not the cooling water can be supplied from the outside.

  The control device 22-2 that has received the external free cooling enable signal Fw opens the water stop valves 47 and 50 and closes the water stop valves 48 and 49. In this way, the cooling water is supplied to the cooler 10 from the external cooling water supply pipe 45, and the cooling water whose temperature is increased by heat exchange is returned to the supply source or the like by the external cooling water return pipe 46. It is. Furthermore, the control device 22-2 stops the rotation of the fan of the cooling tower 30 to zero, that is, stops the inverter 31. As a result, the power consumption of the cooling system 2 can be significantly reduced. Note that the processing of the control device 22-2 when receiving the external freaking possible signal Fw may be interrupted from anywhere in the processing flow shown in FIG.

  Further, at this time, the cooling water Wc from the outside is supplied from the water supply side communication point 41 and the return side communication point 42 from the cooling tower 30 side, so that the adjustment of the bypass pipe 36 and the bypass valve 37 described in the first embodiment is performed. The mechanism can be used as it is. That is, a part of the high-temperature cooling water Wh that has come out of the cooler 10 can be mixed with the cooling water Wc supplied to the cooler 10 to obtain the cooling water Wm. That is, the control device 22-2 controls the bypass valve 37 based on the supply water temperature sensor 39 and the supply water temperature set value TDSSP, thereby maintaining the water temperature of the cooling water Wm at a predetermined temperature.

(Embodiment 3)
In FIG. 7, the outline | summary of the cooling system 3 of this invention is shown. The cooling system 3 according to the present embodiment is different from the cooling system 1 according to the first embodiment in that an external cooling water supply pipe 45 is disposed between the water supply side communication point 41 and the cooler 10 and an external cooling water return pipe 46 is provided. Is disposed between the cooler 10 and the return side communication point 42. A water stop valve 47 is disposed in the external cooling water supply pipe 45. Further, a water stop valve 48 is provided on the water supply side communication point 41 side from the point where the external cooling water supply pipe 45 communicates with the water supply pipe 32. That is, the connection positions of the external cooling water supply pipe 45 and the external cooling water return pipe 46 are different from those in the second embodiment.

  Further, a water stop valve 49 is provided between the communication point between the external cooling water return pipe 46 and the return pipe 34 and the return side communication point 42. Further, a water stop valve 50 is provided on the external cooling water return pipe 46. These water stop valves 47 to 50 are connected to the control device 22-3 and can be opened and closed by an instruction signal from the control device 22. In the water stop valves, as in the second embodiment, the water stop valves 47 to 50 are also referred to as a first valve, a second valve, a third valve, and a fourth valve, respectively.

  Therefore, the elements constituting the circulation unit 13 are the same as those of the circulation unit 12. That is, the cooling tower 30 having a fan that is rotated by the inverter 31, the water supply pipe 32 that sends the cooling water from the cooling tower 30 to the cooler 10, and the cooling water that has been heat-exchanged by the cooler 10 and whose water temperature has increased to the cooling tower 30. The circulation unit 13 is formed including the return pipe 34, the external cooling water supply pipe 45, and the external cooling water return pipe 46.

  The control device 22-3 is electrically connected to the water stop valve and configured to receive an external free cooling possible signal Fw from an external cooling water supply source. This is because the cooling system 3 itself cannot know whether or not the cooling water can be supplied from the outside.

  The control device 22-3 that has received the external free cooling enable signal Fw opens the water stop valves 47 and 50 and closes the water stop valves 48 and 49. In this way, the cooling water is supplied to the cooler 10 from the external cooling water supply pipe 45, and the cooling water whose temperature is increased by heat exchange is returned to the supply source or the like by the external cooling water return pipe 46. It is. Further, the control device 22-3 stops the rotation of the fan of the cooling tower 30 to zero, that is, stops the inverter 31. As a result, the power consumption of the cooling system 3 can be significantly reduced.

  However, in this type (circulation unit 13), the supply temperature cannot be controlled by the bypass pipe 36 and the bypass valve 37. This is because the high-temperature cooling water Wh from the cooler 10 does not return to the bypass pipe 36. That is, when receiving the external free cooling possible signal Fw, the control device 22-3 switches to the external cooling water supply pipe 45 and the external cooling water return pipe 46, and after stopping the cooling tower 30, only the circulation pump 40 is used. Make it work.

(Embodiment 4)
In the present embodiment, a case where a plurality of cooling systems are arranged in series is shown. For example, when the object to be cooled is a liquid or gas and has an original high temperature, it may not be sufficiently cooled by a single cooling system. In such a case, if a plurality of cooling systems are arranged in series, rough heat is taken by the first stage cooling system, and the temperature is further lowered by the second stage cooling system, a large load is placed on the system itself. Therefore, cooling can be performed stably.

  FIG. 8 shows the overall configuration of the cooling system 4. The circulation unit 11 and the cooler 10 form substantially the same configuration as the cooling system 2 of the second embodiment (the control device is different). The circulation unit 112 has substantially the same configuration as the circulation unit 11. However, the difference is that a water-cooled chiller 55 is provided in the circulation unit. The circulation unit 112 has a different number of temperature sensors. This point will be described in detail later. This is for grasping the operation state of the water-cooled chiller 55. The water cooling chiller 55 cools the primary cooling water from the second cooler 110.

  The cooled object 60 is sent from the left side of FIG. 8 and cooled by the cooler 10 to become the cooled object 62. Thereafter, it is further cooled by the second cooler 110 to become a cooled object 64. Moreover, since the cooling water is cooled by the water cooling chiller 55 in the second cooler 110, it can be cooled to a temperature lower than the outside air condition. That is, the cooled object 64 can be cooled to about several degrees.

  On the other hand, one unit is prepared for the control device 23. That is, each of the two circulation units is controlled by one controller 23. Thereby, power consumption as a whole can be reduced. The circulation unit 11 and the circulation unit 112 have substantially the same configuration. Therefore, the equipment and facilities on the circulation unit 11 side are referred to as “first” as necessary, and the equipment and facilities on the circulation unit 112 side that overlap with the circulation unit 11 are referred to as “first”. 2 ". The circulation unit 112 itself is the second circulation unit.

  FIG. 9 shows the configuration of the circulation unit 112, the water cooling chiller 55, and the second cooler 110. The circulation unit 11 has the same configuration as the circulation unit 12 shown in the second embodiment (FIG. 6). The configuration of the circulation unit 112 will be briefly outlined. The second cooling tower 130 is provided with a second water supply pipe 132 that sends the primary side cooling water Wc <b> 2 to the primary side of the water cooling chiller 55.

  In the water-cooled chiller 55, heat is exchanged between the primary-side cooling water and the secondary-side cooling water flowing in the second cooler 110 connected to the secondary side of the water-cooled chiller 55, and the temperature rises. The primary side cooling water Wh2 is discharged. The discharged primary side cooling water Wh2 is transported to the upper part of the second cooling tower 130 by the second return pipe 134, and releases heat while being dropped in the second cooling tower 130.

  A second bypass pipe 136 is formed between the second water supply pipe 132 and the second return pipe 134. A communication point between the second water supply pipe 132 and the second bypass pipe 136 is a second water supply side communication point 141. The communication point between the second return pipe 134 and the second bypass pipe 136 is a second return side communication point 142.

  A second bypass valve 137 is provided in the second bypass pipe 136. A second throttle valve 135 is provided between the second return side communication point 142 and the second cooling tower 130.

  A second outlet water temperature sensor 138 is provided at the outlet of the second cooling tower 130, and a second supply water temperature sensor 139 is provided between the second water supply side communication point 141 and the water cooling chiller 55. . The measured temperature at the second outlet water temperature sensor 138 is TDPV3, and the measured temperature at the second supply water temperature sensor 139 is TDPV4. A second circulation pump 140 is disposed on the water cooling chiller 55 side from the second supply water temperature sensor 139.

  A return water temperature sensor 144 is disposed between the water cooling chiller 55 and the second return side communication point 142. This is because the power consumption of the water-cooled chiller 55 is obtained from the amount of heat exchanged by the water-cooled chiller 55. The return water temperature sensor 144 is not provided in the first circulation unit 11. Note that the temperature measured by the return water temperature sensor 144 is TDPV5.

  Further, in the second water supply pipe 132, between the second water supply side communication point 141 and the second outlet water temperature sensor 138, and in the second return pipe 134, the second return side communication point 142 and the second restrictor. A second external cooling water supply pipe 145 and a second external cooling water return pipe 146 are communicated with the valve 135 in order to take in cooling water from the outside. The second external cooling water supply pipe 145 is provided with a water stop valve 147, and the second external cooling water return pipe 146 is provided with a water stop valve 150.

  Further, between the connection point of the second water supply pipe 132 and the second external cooling water supply pipe 145 and the second outlet water temperature sensor 138, the second external cooling water return pipe 146 and the second return pipe 134 Between them, stop valves 148 and 149 are provided, respectively. These stop valves are coupled to the control device 23 and are configured to be opened and closed by a signal from the control device 23. The water stop valves 147 to 150 are referred to as a fifth valve, a sixth valve, a seventh valve, and an eighth valve, respectively. This is because the designation is continued from the first circulation unit.

  A supply pipe 70 and a water return pipe 71 are also formed between the water-cooled chiller 55 and the second cooler 110 (secondary side of the water-cooled chiller 55). Further, a water supply motor (not shown) is arranged, and cooling water is always circulated between the water cooling chiller 55 and the second cooler 110.

  The circulation unit 112 performs the same operation as the circulation unit 12 (basically, the circulation unit 11). That is, TOWPV is acquired by the outside air wet bulb temperature sensor 24, and the second TDSOP, which is the target value of the outlet water temperature of the second cooling tower 130, is calculated. The second TDOSP is a target value for the second coolant outlet water temperature. Then, the number of rotations of the fan is determined based on the value of the second TDOSS and the water temperature TDPV3 obtained by the second outlet water temperature sensor 138. Note that the second TDOSP and the first TDOSP may have the same value.

  On the other hand, the chilled water Wm2 supplied to the water-cooled chiller 55 is the primary side cooling water Wh2 returned from the water-cooled chiller 55 by the second bypass pipe 136, the second bypass valve 137, and the second throttle valve 135. The primary side cooling water Wc2 supplied from the second cooling tower 130 is mixed and can always be adjusted to a predetermined temperature.

  Further, as shown in FIGS. 3 and 4, the power consumption of the inverter 131 of the second cooling tower 130 can be estimated from the outside wet bulb temperature TOWPV and the second outlet water temperature TDPV3.

  FIG. 10 shows the relationship between the estimated power consumption of the water cooling chiller 55, the difference between the primary side cooling water Wm2 (TDPV4) supplied to the water cooling chiller 55, and the primary side cooling water Wh2 (TDPV5) after the heat exchange. Indicates. Since the water-cooled chiller 55 is a refrigerator, by compressing and evaporating the refrigerant under reduced pressure, the second cooler 110 side (secondary side of the water-cooled chiller 55) and the second circulation unit 112 side (1 of the water-cooled chiller 55). It is a heat pump that moves heat to the next side. Therefore, the amount of work performed inside can be estimated based on the temperature difference between the cooling water on the primary side entering and exiting the water cooling chiller 55.

  In FIG. 10, the horizontal axis represents the difference between the water temperature TDPV5 of the return water temperature sensor 144 and the water temperature TDPV4 of the second supply water temperature sensor 139. The vertical axis represents the estimated power consumption of the water-cooled chiller 55. The estimated power consumption of the water-cooled chiller 55 obtained here is Wch. The estimated power consumption of the second inverter 131 and the second circulation pump 140 is Winv2 and Wp2, respectively. Then, the estimated total power consumption of the power consumed on the second circulation unit 112 side is ΣW2. When ΣW2 is written, ΣW2 = Winv2 + Wp2 + Wch.

  Note that the control device 23 maintains the detection value (TDPV4) of the second supply water temperature sensor 139 constant, and the second circulation pump 140, the second inverter 131, and the water cooling chiller so that the ΣW2 is minimized. If 55 is operated, the total power consumption in the second circulation unit 112 can be minimized.

  Moreover, the control apparatus 23 was able to obtain the same information regarding the 1st circulation unit 11 (refer Embodiment 1). In the first circulation unit 11, assuming that the estimated power consumption of the first inverter 31 is Winv1, and the estimated power consumption of the first circulation pump 40 is Wp1, the estimated total power consumption ΣW1 on the first circulation unit 11 side. Is the sum of these. Stated explicitly, ΣW1 = Winv1 + Wp1.

  Therefore, the control device 23 minimizes ΣW1 + ΣW2 while maintaining the detection value (TDPV2) of the first supply water temperature sensor 39 and the detection value (TDPV4) of the second supply water temperature sensor 139 at predetermined values. In addition, the setting or operating state of the outlet water temperature TDPV1 of the first cooling tower 30, the first circulation pump 40, the outlet water temperature TDPV3 of the second cooling tower 130, the second circulation pump 140, and the water cooling chiller 55 should be changed. For example, power consumption can be minimized with the two cooling systems integrated. Such control can be performed by multivariate analysis, but it is preferable to use a method such as a genetic algorithm.

  As in the second and third embodiments, when the control device 23 receives an external free cooling signal Fw, which is a signal that cooling water from the outside can be used, the second water supply as in the second embodiment. By closing the water stop valves 148 and 149 formed on the pipe 132 and the second return pipe 134 and opening the second external cooling water supply pipe 145 and the second external cooling water return pipe 146, the second external cooling water supply pipe 146 is opened. The cooling tower 130 can be stopped. In other words, there is a possibility of significant energy saving. In this case, the water temperature of the cooling water Wm2 supplied to the water cooling chiller 55 by the second bypass pipe 136 and the second bypass valve 137 can be controlled.

  Further, the cooling system may directly flow cooling water from the outside to the water cooling chiller 55. FIG. 11 shows a circulation unit 113 having a water cooling chiller 55 to which cooling water from the outside is directly supplied. The connection position of the second external cooling water supply pipe 145 and the second external cooling water return pipe 146 is different from the case of FIG. In FIG. 11, these external cooling water related pipes are provided between the water cooling chiller 55 and the cooler 110.

  That is, the second external cooling water supply pipe 145 and the second external cooling water return pipe 146 are communicated with the supply pipe 70 and the water return pipe 71 in order to take in the external coolant. The second external cooling water supply pipe 145 is provided with a water stop valve 147, and the second external cooling water return pipe 146 is provided with a water stop valve 150. Further, water stop valves 148 and 149 are respectively provided at the outlet and the inlet of the cooling water of the water cooling chiller 55 on the second cooler 110 side. These stop valves are coupled to the control device 23 and are configured to be opened and closed by a signal from the control device 23.

  In such a configuration, when the control device 23 receives the external free cooling signal Fw, the control valve 148 and 149 are closed and the second external cooling water supply pipe 145 and the external cooling water return pipe 146 are opened. Thus, the second cooling tower 130 and the circulation pump 140 can be stopped. In other words, there is a possibility of significant energy saving. However, in this case, the temperature of the cooling water Wm2 supplied to the water cooling chiller 55 by the second bypass pipe 136 and the second bypass valve 137 cannot be controlled.

(Embodiment 5)
FIG. 12 shows a solvent recovery system 5 using the cooling system of the present invention. The solvent recovery system is a system that recovers a solvent from air containing a large amount of solvent generated by a coating machine or the like. In the solvent recovery system, there is a source of air containing a large amount of solvent. This is called a solvent generation source. Here, the solvent generation source will be described as the coating machine 80. The solvent generation source is not actually limited to the coating machine 80.

  The solvent recovery system 5 of the present invention includes a coating machine 80 that generates solvent-containing air, a heat exchanger 82, a first gas cooler 84, a second gas cooler 86, a demister 88, and adsorption / desorption. A rotor 90, a drain pipe 92, a control device 22 and an outside air wet bulb temperature sensor 24 are included. The first gas cooler 84 and the second gas cooler 86 are provided with a first circulation unit 11 and a second circulation unit 112, respectively. These two circulation units are configured so that each component device can be controlled by one control device 23. Further, the control device 23 is also coupled to an outside air wet bulb temperature sensor 24, and can obtain an outside air condition.

  Here, the first circulation unit 11, the first gas cooler 84, the second circulation unit 112, the second gas cooler 86, the control device 23, and the outside wet bulb temperature sensor 24 are the same as those in the fourth embodiment. The cooling system 4 shown is configured. Here, the first circulation unit 11 may use the circulation unit 12 or 13 shown in the second and third embodiments, and the second circulation unit 112 may be the circulation unit 113 shown in the fourth embodiment. May be used.

  The heat exchanger 82 following the coating machine 80 is a device for exchanging heat without directly mixing the air D1 containing the solvent at a high temperature from the coating machine 80 and the cold air D6 containing almost no solvent. It is. A drain 83 is provided below the apparatus so that the solvent condensed on the drain pipe 92 can be recovered.

  The first gas cooler 84 is a device that further cools the blown solvent-containing air D2. Reduce the temperature to 40 ° C at once. Since the first circulation unit 11 that sends the cooling water to the first gas cooler 84 only exchanges heat with the atmosphere, only the cooling water having a temperature about 5 ° C. higher than the outside wet bulb temperature is supplied. Can not. That is, from the first gas cooler 84, the solvent-containing air D3 having that temperature is discharged. A drain 85 is also provided below the first gas cooler 84, and the condensed solvent flows through the drain pipe 92.

  The second gas cooler 86 further cools the solvent-containing air D3 cooled by the first gas cooler 84. Cooling water from the second circulation unit 112 is supplied to the second gas cooler 86. Since the second circulation unit 112 is provided with the water-cooled chiller 55, it is possible to supply cooling water of 10 ° C. or less even in summer. The second gas cooler 86 is also provided with a drain 87 below, and allows the condensed solvent to flow through the drain pipe 92.

  The demister 88 is a device for removing mist components from the solvent-containing air D <b> 4 discharged from the second gas cooler 86. The solvent-containing air D4 whose temperature has been lowered by the second gas cooler 86 includes not only the solvent that is condensed and recovered in the apparatus, but also air that appears as mist in the air. Such a mist component can be uniformly recovered by the demister 88. A drain 89 is also provided below the demister 88, and the condensed solvent flows through the drain pipe 92.

  The adsorption / desorption rotor 90 is a device for recovering the solvent from the solvent-containing air D5 that has passed through the demister 88. A cylinder with porous fine particles is configured to repeat the steps of solvent adsorption and desorption while rotating slowly. The solvent in the air (D5) is adsorbed on the fine particles and heated to desorb. The air D6 on which the solvent is adsorbed becomes air containing almost no solvent.

  Next, the flow of solvent-containing air will be described. The solvent-containing air D1 discharged from the coating machine 80 first passes through the heat exchanger 82. This is because the temperature of the solvent-containing air D1 is increased by the heat exchanger 82 because the temperature must be raised to some extent when the air D6 whose temperature has been recovered and lowered in temperature is used again in the coating machine 80. The purpose is to lower and raise the temperature of the regenerated air D6.

  Next, the solvent-containing air D <b> 2 that has passed through the heat exchanger 82 is caused to flow to the first gas cooler 84. Here, the temperature of the solvent-containing air D2 is lowered by the cooling water supplied by the first circulation unit 11, and the solvent is condensed and recovered. Next, the solvent-containing air D <b> 3 that has passed through the first gas cooler 84 is passed through the second gas cooler 86. Cooling water from the second circulation unit 112 is supplied to the second gas cooler 86, and the temperature further decreases. As a result, the condensed solvent can be recovered by the drain pipe 92 here as well.

  The mist component is removed by the demister 88 from the solvent-containing air D4 that has passed through the second gas cooler 86, and the solvent component is almost removed by the adsorption / desorption rotor 90. Accordingly, the solvent-containing air D6 exiting the adsorption / desorption rotor 90 contains almost no solvent, but the temperature is low. Although it can be used as it is, it is preferable to raise the temperature in order to use it in the coating machine 80.

  Therefore, the air that has exited the adsorption / desorption rotor 90 is sent to the heat exchanger 82 and used to take heat away from the high-temperature solvent-containing air D1 from the coating machine 80. The air Dh6 whose temperature has been raised by the heat exchanger 82 is sent again to the coating machine 80 and used. The air Dh6 may be sent to other than the coating machine 80 for use.

  On the other hand, the solvent adsorbed by the adsorption / desorption rotor 90 passes through the desorption process of the adsorption / desorption rotor 90, is again contained in the high-temperature air D 7, and is returned to the first gas cooler 84. As a result, 99% or more of the solvent can be recovered.

  Here, the cooling system 4 including the first circulation unit 11, the first gas cooler 84, the second circulation unit 112, the second gas cooler 86, the control device 23, and the outside air wet bulb temperature sensor 24 is As described in the first to fourth embodiments, the power consumption can be minimized while maintaining the prescribed capability. Therefore, the solvent recovery system 5 using the cooling system 4 can be operated while realizing energy saving.

  As described above, the present invention can be used in a solvent recovery system, and can be widely used as long as cooling or heating is performed using a cooling tower and a heat pump.

1, 2, 3 Cooling system 10 Cooler 11, 12, 13 Circulation unit 22, 22-2, 22-3 Controller 23 Controller 24 Outdoor wet bulb temperature sensor 30 Cooling tower 31 Inverter 32 Water supply pipe 34 Return pipe 35 Restriction Valve 36 Bypass pipe 37 Bypass valve 38 Outlet water temperature sensor 39 Supply water temperature sensor 40 Circulation pump 45 External cooling water supply pipe 46 External cooling water return pipe 47 to 50 Water stop valve
55 Water-cooled chiller 60, 62, 64 Object to be cooled 70 Supply pipe 71 Return pipe
80 coating machine 82 heat exchanger 84 first gas cooler 86 second gas cooler 88 demister 90 adsorption / desorption rotor 83, 85, 87, 89 drain
DESCRIPTION OF SYMBOLS 110 2nd cooler 112, 113 2nd circulation unit 130 2nd cooling tower 131 2nd inverter 132 2nd water supply pipe 134 2nd return pipe 135 2nd throttle valve 136 2nd bypass pipe 137 Second bypass valve 138 Second outlet water temperature sensor 139 Second supply water temperature sensor 140 Second circulation pump 144 Return water temperature sensor 145 Second external cooling water supply pipe 146 Second external cooling water return pipes 147 to 50 Water stop valve

Claims (14)

A cooler for cooling the object to be cooled with cooling water;
A circulation unit that supplies the cooling water to the cooler and cools the cooled cooling water again;
An outside air wet bulb temperature sensor for detecting the outside air wet bulb temperature;
A temperature sensor disposed in the circulation unit, and a controller for controlling a valve, an inverter, and a circulation pump in the circulation unit, connected to a temperature sensor disposed in the circulation unit and the outside air wet bulb temperature sensor;
The circulation unit is
A cooling tower having a fan whose rotation is controlled by the inverter and recooling the cooled cooling water;
A water supply pipe for sending the cooling water whose temperature is lowered in the cooling tower to the cooler;
A return pipe that returns cooling water after depriving heat from the cooler to the cooling tower from the cooler;
A bypass pipe communicating between the water supply pipe and the return pipe;
The circulation pump disposed between a communication point of the water supply pipe and the bypass pipe and the cooler;
A bypass valve provided in the bypass pipe;
A throttle valve provided between a communication point of the return pipe and the bypass pipe and the cooling tower;
An outlet water temperature sensor provided at the outlet of the cooling tower;
A supply water temperature sensor provided between a communication point of the water supply pipe and the bypass pipe and the circulation pump;
The controller is
The detection value of the supply water temperature sensor becomes a predetermined value for the bypass valve, the throttle valve, the inverter, and the circulation pump according to the detection values of the outside air wet bulb temperature sensor, the outlet water temperature sensor, and the supply water temperature sensor. To control and
The circulation unit further includes an external cooling water supply pipe communicated between a communication point of the water supply pipe and the bypass pipe and the cooling tower;
An external cooling water return pipe communicated between a communication point of the return pipe and the bypass pipe and the cooling tower;
A first valve provided in the external cooling water supply pipe;
A communication point between the water supply pipe and the external cooling water supply pipe; a second valve provided between the cooling towers;
A communication point between the return pipe and the external cooling water return pipe; and a third valve provided between the cooling towers;
A fourth valve provided on the external cooling water return pipe,
The control device further controls the first to fourth valves when receiving an external free cooling enabling signal, which is a signal that cooling water from the outside can be used, from the external cooling water supply pipe. A cooling system for supplying the cooling water to the cooler. A cooler for cooling the object to be cooled with cooling water;
A circulation unit that supplies the cooling water to the cooler and cools the cooled cooling water again;
An outside air wet bulb temperature sensor for detecting the outside air wet bulb temperature;
A temperature sensor disposed in the circulation unit, and a controller for controlling a valve, an inverter, and a circulation pump in the circulation unit, connected to a temperature sensor disposed in the circulation unit and the outside air wet bulb temperature sensor;
The circulation unit is
A cooling tower having a fan whose rotation is controlled by the inverter and recooling the cooled cooling water;
A water supply pipe for sending the cooling water whose temperature is lowered in the cooling tower to the cooler;
A return pipe that returns cooling water after depriving heat from the cooler to the cooling tower from the cooler;
A bypass pipe communicating between the water supply pipe and the return pipe;
The circulation pump disposed between a communication point of the water supply pipe and the bypass pipe and the cooler;
A bypass valve provided in the bypass pipe;
A throttle valve provided between a communication point of the return pipe and the bypass pipe and the cooling tower;
An outlet water temperature sensor provided at the outlet of the cooling tower;
A supply water temperature sensor provided between a communication point of the water supply pipe and the bypass pipe and the circulation pump;
The controller is
The detection value of the supply water temperature sensor becomes a predetermined value for the bypass valve, the throttle valve, the inverter, and the circulation pump according to the detection values of the outside air wet bulb temperature sensor, the outlet water temperature sensor, and the supply water temperature sensor. To control and
The circulation unit further includes an external cooling water supply pipe communicated between a communication point of the water supply pipe and the bypass pipe and the supply water temperature sensor,
An external cooling water return pipe communicated between a communication point of the return pipe and the bypass pipe and the cooler;
A first valve provided in the external cooling water supply pipe;
A communication point between the water supply pipe and the bypass pipe; a second valve provided between a communication point between the water supply pipe and the external cooling water supply pipe;
A communication point between the return pipe and the bypass pipe; and a third valve provided between a communication point between the return pipe and the external cooling water return pipe;
A fourth valve provided on the external cooling water return pipe,
The control device further controls the first to fourth valves when receiving an external free cooling enabling signal, which is a signal that cooling water from the outside can be used, from the external cooling water supply pipe. A cooling system for supplying the cooling water to the cooler. The controller is
The target value (TDOSP) of the cooling tower outlet water temperature calculated from the detected value of the outside air wet bulb temperature sensor,
The cooling system of Claim 1 or 2 which controls the said inverter provided in the said cooling tower according to the deviation with the detected value (TDPV1) of the said outlet water temperature sensor. The controller is
A detection value (TDPV1) of the outlet water temperature sensor;
The cooling according to any one of claims 1 to 3, wherein the bypass valve (MV1) and the throttle valve (MV2) are controlled according to a deviation from a detected value (TDPV2) of the supply water temperature sensor. system. The controller is
Furthermore, the estimated pump power consumption Wp estimated from the command power to the circulation pump,
Obtain an estimated total power consumption ΣW from the inverter estimated power consumption Winv estimated from the detected values of the outside air wet bulb temperature sensor and the outlet water temperature sensor,
The cooling system according to any one of claims 1 to 4, wherein the circulating pump and the inverter are controlled so that the estimated total power consumption ΣW is minimized. A second cooler is provided after the cooler according to any one of claims 1 to 5,
A second circulation unit having a refrigerator for supplying secondary side cooling water to the second cooler and cooling the cooled secondary side cooling water again;
The control device is further connected to a temperature sensor disposed in the second circulation unit, a valve, an inverter, a circulation pump, and the refrigerator.
The second circulation unit is
A second cooling tower having a fan whose rotation is controlled by a second inverter and recooling the primary side cooling water supplied to the refrigerator;
A second water supply pipe for sending the primary side cooling water whose temperature has been lowered in the second cooling tower to the refrigerator;
A second return pipe that returns primary side cooling water after depriving heat from the refrigerator to the second cooling tower from the refrigerator;
A second bypass pipe communicating between the second water supply pipe and the second return pipe;
A second circulation pump disposed between a communication point of the second water supply pipe and the second bypass pipe and the refrigerator;
A second bypass valve provided in the second bypass pipe;
A second throttle valve provided between a communication point of the second return pipe and the second bypass pipe and the second cooling tower;
A second outlet water temperature sensor provided at the outlet of the second cooling tower;
A second supply water temperature sensor provided between a communication point of the second water supply pipe and the second bypass pipe and the second circulation pump;
A return water temperature sensor disposed between a communication point of the second return pipe and the second bypass pipe and the refrigerator;
The controller is
The second bypass valve, the second throttle valve, and the second valve according to detection values of the outside air wet bulb temperature sensor, the second outlet water temperature sensor, the second supply water temperature sensor, and the return water temperature sensor. A cooling system that controls the inverter, the second circulation pump, and the refrigerator so that the detection value of the second supply water temperature sensor becomes a predetermined value. The second circulation unit further includes a second external cooling water supply pipe communicated between a communication point of the second water supply pipe, the second bypass pipe, and the second cooling tower;
A second external cooling water return pipe communicated between a communication point of the second return pipe and the second bypass pipe and the second cooling tower;
A fifth valve provided in the second external cooling water supply pipe;
A communication point between the second water supply pipe and the second external cooling water supply pipe; and a sixth valve provided between the second cooling towers;
A communication point between the second return pipe and the second external cooling water return pipe, and a seventh valve provided between the second cooling towers;
An eighth valve provided in the second external cooling water return pipe,
The control device further controls the fifth to eighth valves and receives the second external cooling water when receiving an external free cooling enable signal that is a signal that the cooling water from the outside can be used. The cooling system according to claim 6, wherein cooling water from a supply pipe is supplied to the refrigerator. The refrigerator includes a supply pipe for sending secondary side cooling water to the second cooler;
A return pipe for returning the secondary side cooling water after depriving of heat by the second cooler;
A second external cooling water supply pipe communicated with the supply pipe;
A second external cooling water return pipe communicated with the return pipe;
A fifth valve provided in the second external cooling water supply pipe;
A sixth valve provided between a communication point of the supply pipe and the second external cooling water supply pipe and the refrigerator;
A seventh valve provided between a communication point of the water return pipe and the second external cooling water return pipe and the refrigerator;
An eighth valve provided in the second external cooling water return pipe,
The control device further controls the fifth to eighth valves when receiving a second external free cooling enable signal, which is a signal that cooling water from the outside can be used. The cooling system according to claim 6, wherein cooling water from an external cooling water supply pipe is supplied to the cooler. The controller is
A target value (TDOSP) of the second cooling tower outlet water temperature calculated from the detection value of the outside wet bulb temperature sensor;
The invention according to any one of claims 6 to 8, wherein the second inverter provided in the second cooling tower is controlled according to a deviation from a detection value (TDPV3) of the second outlet water temperature sensor. The cooling system described. The controller is
A detection value (TDPV3) of the second outlet water temperature sensor;
10. The device according to claim 6, wherein the second bypass valve and the second throttle valve are controlled in accordance with a deviation from a detection value (TDPV4) of the second supply water temperature sensor. Cooling system. The controller is
Furthermore, estimated pump power consumption Wp2 estimated from the command power to the second circulation pump,
The second inverter estimated power consumption Winv2 estimated from the detected values of the outdoor wet bulb temperature sensor and the second outlet water temperature sensor;
A second estimated total power consumption ΣW2 is obtained from the estimated power consumption Wch of the refrigerator,
11. The method according to claim 6, wherein the second circulation pump, the second inverter, and the refrigerator are controlled so that the second estimated total power consumption ΣW2 is minimized. Cooling system. The controller is
While the values of the supply water temperature sensor and the second supply water temperature sensor are maintained at predetermined values,
Estimated total power consumption ΣW of the circulation unit;
In order to minimize the sum of the estimated total power consumption ΣW2 of the second circulation unit,
The circulation pump and the inverter;
Cooling system according to claim 11, quoting Claim 6 for controlling the refrigerator and the second circulating pump and the second inverter. A solvent source that generates hot solvent-containing air;
A first gas cooler that cools the solvent-containing air and condenses and recovers the solvent in the solvent-containing air;
A second gas cooler that further cools the solvent-containing air that has passed through the first gas cooler and condenses and recovers the solvent in the solvent-containing air; and
A demister that recovers a mist component from the solvent-containing air that has passed through the second gas cooler;
An adsorption / desorption rotor that removes the solvent from the solvent-containing air that has passed through the demister and discharges the regenerated air;
A drain pipe for recovering the solvent in the solvent-containing air recovered from the first gas cooler, the second gas cooler, and the demister;
The solvent recovery system which cools the said 1st gas cooler and the said 2nd gas cooler by the said circulation unit and the said 2nd circulation unit in the cooling system in any one of Claim 6 thru | or 12. The solvent recovery system according to claim 13, further comprising a heat exchanger that exchanges heat between the regeneration air discharged from the adsorption / desorption rotor and the solvent-containing air generated from the solvent generation source.