JP2020106235A - Cooling system and cooling method - Google Patents

Abstract

To provide a technique capable of cooling multiple loads as predetermined while saving a flow of cooling water as further as possible even in a case that a temperature of the cooling water is varied.SOLUTION: The present invention relates to a cooling system comprising: pumping means which pumps cooling water for cooling multiple loads; and adjustment means for adjusting flows of the cooling water which is pumped by the pumping means and to flow into a first load and a second load among the multiple loads. A temperature of a cooling object of the second load to exchange heat with the cooling water is equal to or higher than a temperature of a cooling object of the first load to exchange heat with the cooking water. The adjustment means adjusts the flow of the cooling water which is pumped by the pumping means and to flow into the second load without flowing into any load among the multiple loads and the flow of the cooling water which is pumped by the pumping means and to flow through the first load into the second load.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cooling system and a cooling method.

A system in which cooling water is circulated through a plurality of loads is disclosed (for example, Patent Documents 1-3).

JP 2001-65929 A Japanese Patent No. 3710712 JP, 2010-86748, A

In the case of a cooling system that uniformly distributes cooling water to each load by a pump, the load on the pump is considered to be large.

Further, in the season when the wet-bulb temperature of the atmosphere is relatively high, such as the season from rainy season to autumn, the temperature of the cooling water may increase. Then, in order to cool the load having a relatively high heat generation density as a predetermined amount, the flow rate of the circulating cooling water is increased. However, when the flow rate of the cooling water is determined on the basis of the load having a relatively high heat generation density as described above, the cooling water excessively flows into the load having a relatively low heat generation density. That is, the power of the pump and the cooling water may be wasted.

Therefore, it is an object of the present application to provide a technique capable of cooling a plurality of loads in a predetermined manner while reducing the flow rate of the cooling water as much as possible even when the temperature of the cooling water changes. ..

In order to solve the above-mentioned problems, the present invention provides a flow rate of cooling water that flows into a second load via a first load of a plurality of loads and without passing through a load other than the second load. It was decided to adjust the flow rate of the cooling water flowing into the second load.

More specifically, the present invention relates to a pumping unit that pumps cooling water that cools a plurality of loads, and cooling water that is pumped by the pumping unit and that flows into a first load and a second load of the plurality of loads. The temperature of the cooling target of the second load that exchanges heat with the cooling water is equal to or higher than the temperature of the cooling target of the first load that exchanges heat with the cooling water. Is the flow rate of the cooling water that is pumped by the pumping means and flows into the second load without flowing into any of the plurality of loads, and is pumped by the pumping means through the first load. A cooling system for adjusting the flow rate of cooling water flowing into the second load.

With such a cooling system, it is possible to cause the cooling water to flow in the order of the first load and the second load and exchange heat with each load. In addition, the cooling water can be caused to flow into the second load without passing through the loads other than the second load to exchange heat with the second load. Therefore, depending on the conditions such as the temperature of the cooling water and the temperature of the cooling target of each load, the flow rate of the cooling water that exchanges heat with each load in the order of the first load, the second load, and the other than the second load. The flow rate of the cooling water flowing into the second load can be adjusted without passing through the load. That is, with such a cooling system, the flow rate of the cooling water can be reduced as much as possible depending on the situation.

Further, the cooling system mixes the cooling water pumped by the pumping means and not flowing into any one of the plurality of loads, and the cooling water pumped by the pumping means and flowing into the first load. The mixing unit may further include a mixing unit that adjusts the flow rate of the cooling water to be mixed in the mixing unit, and sends the adjusted cooling water to the second load.

With such a cooling system, the flow rate of the cooling water to be mixed can be adjusted according to the conditions such as the temperature of the cooling water and the temperature of the cooling target of each load. That is, in such a cooling system, in addition to circulating the cooling water so as to exchange heat with each load in the order of the first load and the second load depending on the situation, a plurality of loads may be added to the cooling water. It is also possible to mix the cooling water that has not flowed into any of the loads and send the mixed cooling water to the second load. That is, the flow rate of the cooling water can be reduced as much as possible.

Further, in the cooling system, when the temperature of the cooling water pumped by the pumping means is equal to or lower than a predetermined temperature, the adjusting means pumps the pumping means by the pumping means in the mixing section to apply any load to the plurality of loads. The cooling water that has not flowed in may not be mixed with the cooling water that has been pumped by the pumping means and that has flowed into the first load.

With such a cooling system, when the temperature of the cooling water pumped by the pumping means is equal to or lower than the predetermined temperature, the cooling water does not flow into any of the plurality of loads and the cooling water is discharged into the second load. Inflow to is suppressed. In other words, the cooling water can be made to flow in order of the first load and the second load to exchange heat with each load. That is, the cooling water that has exchanged heat with the first load can be used for cooling the second load. Therefore, the flow rate of the cooling water can be reduced.

Further, in the cooling system, when the temperature of the cooling water pumped by the pumping means is higher than a predetermined temperature, the adjusting means pumps the pumping means by the pumping means in the mixing section to apply any of the plurality of loads. You may mix the cooling water which has not flowed in, and the cooling water which was pressure-fed by the pressure-feeding means and which flowed into the first load.

When the temperature of the cooling water pressure-fed by the pressure-feeding means is higher than a predetermined temperature, in the method of heat-exchange the cooling water in the order of the first load and the second load, heat is exchanged with the first load and flows out. The temperature of the cooling water may be a temperature at which it is difficult to cool the second load as predetermined. Therefore, it may be necessary to increase the flow rate of the cooling water flowing into the first load. However, in the cooling system as described above, when the temperature of the cooling water pumped by the pumping means is higher than the predetermined temperature, the cooling water that has not flowed into any of the plurality of loads is , And the cooling water that has flowed into the first load can be mixed, and the mixed cooling water can flow into the second load and exchange heat with the second load. Therefore, the increase in the flow rate of the cooling water flowing into the first load is suppressed. That is, an increase in the total flow rate of cooling water is suppressed.

Further, in the cooling system, the pressure feeding means is a pump, and the pressure feeding means is capable of cooling the load having the highest temperature of the cooling target that exchanges heat with the cooling water among the plurality of loads to the second predetermined temperature. The cooling water may be pumped at a flow rate that is possible and at a flow rate higher than the minimum flow of the pump.

With such a cooling system, the flow rate of the cooling water circulating through the plurality of loads can be reduced as much as possible while suppressing the influence on the operation of the pump.

In addition, the cooling system has a plurality of loads, and the cooling water is pumped by the pumping means and has not flowed into any of the plurality of loads, and the cooling water is pumped by the pumping means, and the first load or The second mixing unit further includes a second mixing unit that mixes with the cooling water that has flowed into the second load, and the adjusting unit adjusts the flow rate of the cooling water to be mixed in the second mixing unit, and adjusts a plurality of the adjusted cooling waters. The temperature of the cooling target of the third load that exchanges heat with the cooling water may be equal to or higher than the temperature of the cooling target of the second load that exchanges heat with the cooling water. ..

With such a cooling system, the flow rate of the cooling water to be mixed in the second mixing unit can be adjusted according to the conditions such as the temperature of the cooling water and the temperature of the cooling target of each load. That is, with such a cooling system, the cooling water can be circulated so as to exchange heat with the respective loads in the order of the first load, the second load, and the third load depending on the situation. Also, by mixing the cooling water that circulates in this way with the cooling water that does not flow into any of the multiple loads, and send the mixed cooling water to the second load or the third load. Can also That is, the flow rate of the cooling water can be reduced as much as possible.

The present invention can also be viewed as a method aspect. That is, for example, a pressure-feeding step of pressure-feeding cooling water that cools a plurality of loads, and a flow rate of cooling water that is pressure-fed in the pressure-feeding step and that flows into the first load and the second load of the plurality of loads is adjusted. The temperature of the cooling target of the second load that exchanges heat with the cooling water is equal to or higher than the temperature of the cooling target of the first load that exchanges heat with the cooling water. And the flow rate of the cooling water that is pumped in the second load without flowing into any of the plurality of loads, and is pumped in the pumping process, and then the second load is passed through the first load. The cooling method may be a method of adjusting the flow rate of the cooling water flowing into the.

In addition, the cooling method, the heat generation amount per unit area of the cooling target of the first load, and the heat generation amount per unit area of the cooling target of the second load, the cooling water flowing into the second load. It may further include a calculation step of repeatedly calculating the flow rate of the cooling water flowing into the second load so that the flow rate becomes equal to or higher than the flow rate of the cooling water flowing into the first load.

With such a cooling method, in addition to the case where the cooling water is made to flow in the order of the first load and the second load to exchange heat with each load, the cooling water can be applied to any of the plurality of loads. It is possible to calculate the flow rate of the cooling water when flowing into the second load without causing the flow. Further, the calculated flow rate can be changed according to the heat generation amount per unit area of the cooling target of the first load and the heat generation amount per unit area of the cooling target of the second load. That is, with such a cooling method, the flow rate of the cooling water can be reduced as much as possible.

The above cooling system and cooling method provide a technique capable of cooling a plurality of loads in a predetermined manner while reducing the flow rate of the cooling water as much as possible even when the temperature of the cooling water fluctuates. You can

FIG. 1 shows an example of an outline of a cooling water circulation device according to this embodiment. FIG. 2 shows an example of the outline of the circulation of the cooling water realized by the cooling water circulation device when the temperature measured by the thermometer is 25 degrees or less. FIG. 3 shows an example of an outline of a processing flow for calculating the flow rate of the circulating cooling water in the case of the series flow. FIG. 4 shows an example of the outline of the circulation of the cooling water realized by the cooling water circulation device when the temperature measured by the thermometer is higher than 25 degrees. FIG. 5 shows an example of the outline of the processing flow for calculating the flow rate of the circulating cooling water in the case of the mixing flow. FIG. 6 shows an example of the outline of a detailed processing flow for calculating the flow rate of the circulating cooling water in the case of the mixing flow. FIG. 7 shows an example of an outline of a detailed processing flow for calculating the flow rate of the circulating cooling water in the case of the mixing flow. FIG. 8 shows an example of an outline of a detailed processing flow for calculating the flow rate of the circulating cooling water in the case of the mixing flow. FIG. 9 shows an example of an outline of a conventional cooling water circulation device. FIG. 10 shows an example of the outline of the cooling water circulation device. FIG. 11 shows an example of the outline of the cooling water circulation device.

Hereinafter, embodiments of the present invention will be described. The embodiment described below is an example of the embodiment of the present invention, and the technical scope of the present invention is not limited to the following modes.

<Device configuration>
FIG. 1 shows an example of an outline of a cooling water circulation device 50 according to this embodiment. The cooling water circulation device 50 circulates the cooling water to the high heat generation density load 1, the medium heat generation density load 2, and the low heat generation density load 3 for heat exchange. Here, the high heat generation density load 1, the medium heat generation density load 2, and the low heat generation density load 3 are devices that generate heat, such as a server provided in a data center. The high heat generation density load 1 has a higher heat generation density than the middle heat generation density load 2, and the temperature of the cooling target portion is equal to or higher than the temperature of the cooling target portion of the middle heat generation density load 2. Further, the medium heat generation density load 2 has a higher heat generation density than the low heat generation density load 3, and the temperature of the cooling target portion is equal to or higher than the temperature of the cooling target portion of the low heat generation density load 3. Here, the high heat generation density load 1, the middle heat generation density load 2, and the low heat generation density load 3 are examples of the "plurality of loads" in the present invention. The low heat generation density load 3 is an example of the "first load" in the present invention. The middle heat generation density load 2 is an example of the "second load" in the present invention. The high heat generation density load 1 is an example of the "third load" in the present invention. In addition, hereinafter, each load means a high heat generation density load 1, a medium heat generation density load 2, and a low heat generation density load 3. The cooling water circulation device 50 is an example of the "cooling system" in the present invention.

The cooling water circulated to each load is manufactured in the cooling device 4. The cooling device 4 is, for example, a refrigerator using a cooling tower.

The cooling water circulation device 50 includes a circulation pipe 20 in which the cooling water exchanges heat with the low heat generation density load 3, the medium heat generation density load 2, and the high heat generation density load 1, and circulates to the cooling device 4. The cooling water circulation device 50 is provided with the pump 5 near the outlet where the cooling water flows out from the cooling device 4. The pump 5 pumps the cooling water produced in the cooling device 4 to each load through the circulation pipe 20. Here, the pump 5 is an example of the “pressure feeding means” of the present invention. The circulation pipe 20 also has a pipe for returning cooling water to the cooling device 4 without exchanging heat with the high heat density load 1, the medium heat density load 2, or the low heat density load 3.

Further, the cooling water circulation device 50 is branched from the pipe located downstream of the pump 5, and when the cooling water which is the circulation pipe 20 and exchanges heat with the medium heat generation load 2 flows into the high heat generation load 1. A branch pipe 21 that joins the passing circulation pipe 20 is provided. Then, a three-way valve 6A is provided at a portion where the branch pipe 21 and the circulation pipe 20 merge. Here, the portion where the branch pipe 21 and the circulation pipe 20 join together is an example of the “second mixing portion” of the present invention.

The three-way valve 6A includes valves at the inlet on the side of the branch pipe 21 at the merging portion and the inlet on the side of the circulation pipe 20 at the merging portion. Further, the three-way valve 6A includes a valve at the outlet of the confluence portion.

Further, the cooling water circulation device 50 is branched from the pipe located downstream of the pump 5, and when the cooling water that is the circulation pipe 20 and exchanges heat with the low heat generation density load 3 flows into the middle heat generation density load 2. A branch pipe 22 that joins with the passing circulation pipe 20 is provided. Then, a three-way valve 6B is provided at a portion where the branch pipe 22 and the circulation pipe 20 meet. Here, the portion where the branch pipe 22 and the circulation pipe 20 meet is an example of the “mixing portion” of the present invention.

The three-way valve 6B is provided with valves at the inlet on the side of the branch pipe 22 at the confluence and at the inlet on the side of the circulation pipe 20 at the confluence. Further, the three-way valve 6B includes a valve at the outlet of the confluence portion.

Further, the cooling water circulation device 50 includes a valve 7. The valve 7 is provided near the outlet where the cooling water flows out from the low heat generation density load 3.

Further, the cooling water circulation device 50 is provided with the pumps 8A and 8B as necessary when the pump 5 alone cannot pump. The pump 8A is provided upstream of the three-way valve 6A provided in the middle of the circulation pipe 20 and pumps the cooling water toward the three-way valve 6A. Further, the pump 8B is provided on the upstream side of the three-way valve 6B provided in the middle of the circulation pipe 20 and pumps the cooling water toward the three-way valve 6B.

Further, the cooling water circulation device 50 includes a thermometer 9. The thermometer 9 is provided downstream of the pump 5 and near the pump 5. The thermometer 9 measures the temperature of the cooling water pumped by the pump 5 (the temperature of the cooling water flowing out from the cooling device 4).

Further, the cooling water circulation device 50 includes the control device 10. The control device 10 controls driving of the pump 5. Further, the control device 10 controls the opening degree of the valves included in the three-way valves 6A and 6B. Further, the control device 10 acquires the value of the temperature measured by the thermometer 9. The control device 10 is a computer having a processor such as a CPU, a main storage device such as a RAM or a ROM, and an auxiliary storage device such as a hard disk drive. An operating system (OS), various programs, various tables, etc. are stored in the auxiliary storage device, and the programs stored therein are loaded into the work area of the main storage device and executed. By controlling the units and the like, it is possible to realize each function, which will be described later, that matches a predetermined purpose. Here, the three-way valves 6A and 6B, the thermometer 9, and the control device 10 are examples of the "adjusting means" in the present invention.

Further, the cooling water circulation device 50 includes a valve 11. The valve 11 is the above-mentioned circulation pipe 20, and is in the middle of the circulation pipe 20 for returning the cooling water to the cooling device 4 without exchanging heat with the high heat generation density load 1, the medium heat generation density load 2, and the low heat generation density load 3. It is provided in.

<Flow rate adjustment example 1>
FIG. 2 shows an example of the outline of the circulation of the cooling water realized by the cooling water circulation device 50 when the temperature measured by the thermometer 9 is, for example, 25 degrees or less. When the temperature measured by the thermometer 9 is, for example, 25 degrees or less, the control device 10 controls to close the valve provided at the inlet of the three-way valve 6A on the side of the branch pipe 21. Further, the control device 10 controls to open a valve provided at the inlet of the three-way valve 6A on the side of the circulation pipe 20.

When the acquired temperature is, for example, 25 degrees or lower, the control device 10 controls to close the valve provided at the inlet of the three-way valve 6B on the side of the branch pipe 22. Further, the control device 10 controls to open the valve provided at the inlet of the three-way valve 6B on the circulation pipe 20 side. By controlling the opening of the valves of the three-way valves 6A and 6B as described above, the cooling water pumped from the pump 5 receives heat from the low heat density load 3, the medium heat density load 2, and the high heat density load 1 in this order. It is exchanged and circulated to the cooling device 4.

Further, in the circulation method shown in FIG. 2, the cooling water pumped from the pump 5 does not flow into the high heat generation density load 1 without passing through the medium heat generation density load 2. Further, in the circulation method shown in FIG. 2, the cooling water pumped from the pump 5 does not flow into the intermediate heat generation density load 2 without passing through the low heat generation density load 3. The circulation method as shown in FIG. 2 is hereinafter referred to as a series flow. The temperature (25 degrees) measured by the thermometer 9 is an example of the “predetermined temperature” in the present invention. In addition, the series flow is the "mixing section of the present invention, the cooling water that is pumped by the pumping means and has not flowed into any of the plurality of loads is pumped by the pumping means and is fed to the first load. It does not mix with the inflowing cooling water”.

FIG. 3 shows an example of an outline of a processing flow for calculating the flow rate of the circulating cooling water in the case of the series flow.

(S1)
In step S1, the control device 10 sets the target temperature when the high heat generation density load 1 is cooled. Here, it is assumed that the high heat generation density load 1 is a device that must be cooled to, for example, 40 degrees or less. Here, the target temperature when the high heat generation density load 1 is cooled is an example of the “second predetermined temperature” in the present invention.

(S2)
In step S2, the amount of change in temperature when the cooling water exchanges heat with each load is calculated.

Here, the equation (1) generally holds between the flow rate Q of the fluid that exchanges heat with the load and the amount of change ΔT in the temperature of the fluid before and after the heat exchange.
Q=1.16×q/ΔT (1)
However, q is the load density [kW/m ² ].

When circulating the cooling water in the series flow, the flow rates Q of the cooling water that exchange heat with the respective loads are equal to each other. Therefore, the following expression (2) is established.
1.16×q ₁ /ΔT ₁ =1.16×q ₂ /ΔT ₂ =1.16×q ₃ /ΔT ₃ (2)
However, q ₁ is the load density of the high heat generation density load 1, and is set to, for example, 16 kW/m ² . Further, q ₂ is the load density of the medium heat generation density load 2, and is set to, for example, 10 kW/m ² . Further, q ₂ is an example of the “heat generation amount per unit area of the cooling target of the second load” of the present invention. Further, q ₃ is the load density of the low heat generation density load 3, and is set to, for example, 5 kW/m ² . Further, q ₃ is an example of the “heat generation amount per unit area of the cooling target of the first load” of the present invention.

Further, ΔT ₁ is the amount of change in the temperature of the cooling water when heat is exchanged with the high heat generation density load 1. Further, ΔT ₂ is the amount of change in the temperature of the cooling water when heat is exchanged with the intermediate heat generation density load 2. Further, ΔT ₃ is the amount of change in the temperature of the cooling water when heat is exchanged with the low heat generation density load 3.

Therefore, from the above formula (2), the temperature measured by the thermometer 9 (for example, 25 degrees), and the target temperature (40 degrees) when the high heat density load 1 is cooled, ΔT ₁ is estimated to be about 7 degrees. To be done. Further, it is estimated that ΔT ₂ is about 5 degrees and ΔT ₃ is about 3 degrees.

(S3)
In step S3, the flow rate Q of the circulating cooling water is calculated to be, for example, about 2.4 m ³ /h/m ² from the amount of change in temperature calculated in step S2 and the equation (1). Then, the control device 10 determines whether or not the calculated flow rate Q is equal to or higher than the minimum flow of the pump 5. Then, when it is determined that the calculated flow rate Q is equal to or higher than the minimum flow of the pump 5, the control device 10 determines the calculated flow rate Q as the circulation flow rate Q ₀ . On the other hand, when it is determined that the calculated flow rate Q is less than the minimum flow rate of the pump 5, the minimum flow rate of the pump 5 is determined as the circulation flow rate Q ₀ . Here, the minimum flow is, for example, about 40% of the rated flow rate of the pump 5. Then, the control device 10 controls the valve 11 to be in the open state so that the calculated flow rate Q is passed through each load. If the valve 11 remains closed, the circulation flow rate Q _{0, which} is larger than the flow rate Q, will flow to each load. Therefore, by opening the valve 11, some cooling water is released to the valve 11 side and flows to each load. The flow rate is reduced. Further, the control device 10 may adjust the opening degree of the valve 7 when it is desired to control the flow rate of the cooling water flowing into each load in detail.

<Flow rate adjustment example 2>
FIG. 4 shows an example of an outline of the circulation of cooling water realized by the cooling water circulation device 50 when the temperature measured by the thermometer 9 is higher than 25 degrees, for example. When the temperature measured by the thermometer 9 is higher than 25 degrees, for example, the control device 10 controls to open the valve provided at the branch pipe 21 side inlet of the three-way valve 6A. Further, the control device 10 controls to open a valve provided at the inlet of the three-way valve 6A on the side of the circulation pipe 20.

In addition, when the acquired temperature is higher than 25 degrees, for example, the control device 10 controls to open the valve provided at the inlet of the three-way valve 6B on the side of the branch pipe 22. Further, the control device 10 controls to open the valve provided at the inlet of the three-way valve 6B on the circulation pipe 20 side. By controlling the opening degree of the valves of the three-way valves 6A and 6B as described above, the cooling water pumped from the pump 5 is not only circulated in the series flow, but also the cooling water pumped from the pump 5 has medium heat generation. It flows into the high heat generation density load 1 without passing through the density load 2. The cooling water pumped from the pump 5 flows into the intermediate heat generation density load 2 without passing through the low heat generation density load 3. The circulation method as shown in FIG. 4 is hereinafter referred to as a mixing flow. In addition, the mixing flow is the cooling water that is pumped by the pumping means and does not flow into any of the plurality of loads and the cooling water that is pumped by the pumping means and flows into the first load of the present invention. And, are mixed with each other.”

FIG. 5 shows an example of the outline of the processing flow for calculating the flow rate of the circulating cooling water in the case of the mixing flow. Here, in the present embodiment, for example, the temperature of the cooling water before heat exchange with the high heat generation density load 1 is 35 degrees, and the temperature of the cooling water after heat exchange with the high heat density load 1 is 40 degrees. Then, the flow rate of the cooling water is calculated (that is, ΔT ₁ is 5 degrees). Moreover, the temperature range of the cooling water supplied from the cooling device 4 was between 25 degrees and 32 degrees. Further, in calculating the flow rate of the cooling water in the mixing flow, the following constraint conditions are set.

Specifically, the temperature T 3 _{—O of the} cooling water that flows out by exchanging heat with the low heat generation density load 3 is set to T 3 _—O ≦34 degrees. Further, the change amount ΔT ₃ ≦5 degrees of the temperature of the cooling water when heat is exchanged with the low heat generation density load 3. With such constraint conditions, ΔT ₃ is 2 degrees even when the temperature of the cooling water supplied from the cooling device 4 is the upper limit value of 32 degrees. Here, the load density q ₁ of the high heat generation density load 1 is, for example, 16 kW/m ² , and the load density q ₃ of the low heat generation density load ₃ is, for example, 5 kW/m ² . That is, the ratio of q ₁ to q ₃ is approximately 3:1. In other words, from the formula (1), if ΔT ₃ is 1/3 or more of ΔT ₁ , the flow rate of the cooling water that exchanges heat with the low heat generation density load 3 is equal to that of the cooling water that exchanges heat with the high heat generation density load 1. Therefore, the mixing flow is established. Further, even if the temperature of the cooling water supplied from the cooling device 4 fluctuates, ΔT ₃ becomes 1/3 or more of ΔT ₁ , so that the mixing flow is established.

Similarly, the temperature T 2 — _{O of the} cooling water that flows out by exchanging heat with the intermediate heat generation density load 2 is set to T 2 — _O ≦38 degrees. In addition, the amount of change in temperature of the cooling water when heat is exchanged with the medium heat generation density load 2, ΔT ₂ ≦5 degrees. With such constraint conditions, ΔT ₂ is 4 degrees even when the temperature of the cooling water that flows out through heat exchange with the low heat generation density load 3 is the upper limit value of 34 degrees. Here, the load density q ₁ of the high heat generation density load 1 is, for example, 16 kW/m ² , and the load density q ₂ of the middle heat generation density load ₂ is, for example, 10 kW/m ² . That is, the ratio between q ₁ and q ₂ is approximately 3:2. In other words, according to equation (1), if ΔT ₂ is ⅔ or more of ΔT ₁ , the flow rate of the cooling water that exchanges heat with the medium heat generation density load 2 is equal to that of the cooling water that exchanges heat with the high heat generation density load 1. Therefore, the mixing flow is established. Further, even when the temperature of the cooling water that flows out by exchanging heat with the low heat generation density load 3 changes, ΔT ₂ becomes 2/3 or more of ΔT ₁ , so that the mixing flow is established.

In consideration of the above constraint conditions, the flow rate of the cooling water circulating each load in the mixing flow is calculated as shown in FIG. The details of the flow rate calculation process will be described below.

(S10)
In step S10, the control device 10 calculates the flow rate of the cooling water that exchanges heat with the low heat generation density load 3. Details of the calculation method will be described later.

(S20)
In step S20, the control device 10 calculates the flow rate of the cooling water that exchanges heat with the medium heat generation density load 2. Details of the calculation method will be described later.

(S30)
In step S30, the control device 10 calculates the flow rate of the cooling water that exchanges heat with the high heat generation density load 1. Then, the control device 10 calculates the total flow rate of the cooling water circulating through each load. Details of the calculation method will be described later.

FIG. 6 shows an example of the outline of the detailed processing flow of step S10.
(S100)
In step S100, the control device 10 determines whether or not the temperature T ₀ measured by the thermometer 9 is 29 degrees or less.

(S101)
When it is determined in step S101 that the temperature T ₀ is 29 degrees or lower, the control device 10 sets ΔT ₃ to 5 degrees.

(S102)
In step S102, when it is not determined that the temperature T ₀ is equal to or lower than 29 degrees, the control device 10 sets the temperature T 3 — _i of the cooling water flowing into the low heat generation density load 3 to the temperature measured by the thermometer 9. Set to T ₀ .

(S103)
In step S203, the control device 10 sets the temperature _{T3_O} of the cooling water that exchanges heat with the low heat generation density load 3 and flows out to 34 degrees. The control device executes the operation of _{ΔT 3} = _T 3_O _-T 3_i.

(S104)
In step S104, as Equation (1), calculation of the flow rate Q ₃ of the low heat generation density load 3 and the fluid to heat exchange is performed. Also, the calculation of T ₃ — _O =T ₃ — _i +ΔT ₃ is executed.

FIG. 7 shows an example of the outline of the detailed processing flow of step S20.
(S200)
In step S200, control device 10 sets ΔT ₂ to 5 degrees.

(S201)
In step S201, the control device 10 determines whether or not the temperature T 3 — _{O of the} cooling water that exchanges heat with the low heat generation density load 3 and flows out is 33 degrees or lower.

(S202)
When it is determined in step S202 that the temperature _{T3_O} is 33 degrees or less, the control device 10 sets the temperature _{T2_i} of the cooling water flowing into the middle heat generation density load 2 to _{T3_O} .

(S203)
When it is not determined in step S203 that the temperature _{T3_O} becomes 33 degrees or less, the control device 10 sets the temperature _{T2_i} of the cooling water flowing into the intermediate heat generation density load 2 to 33 degrees. Further, the control device 10 sets the temperature T 2 _{_O} of the cooling water that flows out by exchanging heat with the medium heat generation density load 2 to 38 degrees.

(S204)
In step S204, the control device 10 executes the calculation of ΔT ₂ =T _{2_O} −T _{2_i} .

(S205)
In step S205, the control unit 10, as equation (1), to perform the calculation of the flow rate Q ₂ of the middle heat density loads 2 and cooling water for heat exchange. Further, the control device 10 executes the calculation of T _{2_O} =T _{2_i} +ΔT ₂ .

(S206)
In step S206, the control unit 10, the flow rate Q ₂ of the middle heat density load 2 and the cooling water heat exchange, determining whether a low heat generation density load 3 and the cooling water heat exchanger flow Q ₃ or more To do. Then, when it is determined that Q ₂ is equal to or greater than Q _{3, the} process proceeds to step S30.

(S207)
In step S207, _{if Q 2} is not determined to be _{Q 3} or more, the control unit _10, the calculation of _{T 2_i = {T 2_i × Q} 3 + T 0 × (Q 2 -Q 3)} / Q 2 Execute. Further, the control device 10 executes the calculation of T _{2_O} =T _{2_i} +ΔT ₂ .

(S208)
In step S208, the control device 10 determines whether or not the temperature T 2 — _{O of the} cooling water that exchanges heat with the medium heat generation density load 2 and flows out is 38 degrees or higher. Then, if T 2 — _O ≧38, the process proceeds to step S30. On the other hand, when T 2 — _O ≧38 is not satisfied, the process returns to step S204. That is, in step S20, Q ₂ is repeatedly calculated.

FIG. 8 shows an example of the outline of the detailed processing flow of step S30.
(S300)
In step S300, control device 10 sets ΔT ₁ to 5 degrees.

(S301)
In step S301, the control device 10 determines whether or not the temperature T 2 — _{O of the} cooling water that exchanges heat with the medium heat generation density load 2 and flows out is 35 degrees or less.

(S302)
When it is determined in step S302 that the temperature T _{2_O} is equal to or lower than 35 degrees, the control device 10 sets the temperature T _{1_i} of the cooling water flowing into the high heat generation density load 1 to T _{2_O} .

(S303)
When it is not determined in step S303 that the temperature T _{2_O} becomes 35 degrees or lower, the control device 10 sets the temperature T _{1_i} of the cooling water flowing into the high heat generation density load 1 to 35 degrees. Further, the control device 10 sets the temperature T 1 — _O of the cooling water that exchanges heat with the high heat generation density load 1 and flows out to 40 degrees.

(S304)
In step S304, the control device 10 executes the calculation of ΔT ₁ =T _{1_O} −T _{1_i} .

(S305)
In step S305, the control device 10 executes the calculation of the flow rate Q ₁ of the cooling water that exchanges heat with the high heat generation density load 1 according to the equation (1). Further, the control device 10 executes the calculation of T _{1_O} =T _{1_i} +ΔT ₁ .

(S306)
Step In S306, the control unit 10, a high heat generation density load 1 and the flow rate to Q ₁ coolant heat exchange, determining whether a medium heat generation density load 2 and the cooling water heat exchanger flow Q ₂ or more To do.

(S307)
When it is determined in step S307 that Q ₁ is equal to or greater than Q ₂ , the control device 10 determines the largest flow rate among Q ₁ , Q ₂ , and Q ₃ as the circulation flow rate Q ₀ . Then, the control device 10 controls the power of the pump 5 to pump the determined Q ₀ . Further, the control device to the load, _Q 1 that is calculated, _{Q 2,} and as cooling water _{Q 3} flows, three-way valve 6A, 6B of the opening, the valve 7 of the opening, the pump 8A, 8B And the opening of the valve 11 are controlled. In addition, as energy saving of the power of the pumps 8A and 8B, pressure control may be used so that the discharge pressure of the pumps 8A and 8B becomes a predetermined value.

(S308)
In step S308, when it is not determined that Q ₁ is equal to or greater than Q ₂ , the control device 10 _calculates T ₁ — _i ={T 1 — _i ×Q ₂ +T ₀ ×(Q ₁ −Q ₂ )}/Q ₁ . Execute. Further, the control device 10 executes the calculation of T _{1_O} =T _{1_i} +ΔT ₁ .

(S309)
In step S309, the control device 10 determines whether or not the temperature _{T1_O of the} cooling water that exchanges heat with the high heat generation density load 1 and flows out is 40 degrees or more. Then, when T 1 — _O ≧40, the process proceeds to step S307 to determine the circulation flow rate Q ₀ . On the other hand, if T _{1_O} ≧40 is not satisfied, the process returns to step S304. That is, in step S30, Q ₁ is repeatedly calculated.

<Flow rate comparison example>
FIG. 9 shows an example of an outline of a conventional cooling water circulation device 60. The cooling water circulation device 60 does not include the three-way valves 6A and 6B. Further, the cooling water circulation device 60 does not include a pipe through which the cooling water that has exchanged heat with the medium heat generation density load 2 flows into the high heat generation density load 1. Further, the cooling water circulation device 60 does not include a pipe through which the cooling water that has exchanged heat with the low heat generation density load 3 flows into the middle heat generation density load 2.

Instead, the cooling water circulation device 60 is provided with a valve 51A provided near the outlet where the cooling water flows out from the high heat generation density load 1. Further, the cooling water circulation device 60 is provided with a valve 51B provided in the vicinity of the outlet where the cooling water flows out from the medium heat generation density load 2.

The cooling water circulation device 60 as described above can separately supply the cooling water pumped from the pump 5 to each load by controlling the opening degrees of the valves 7, 51A, and 51B. In other words, the cooling water circulation device 60 cannot circulate the cooling water like the series flow and the mixing flow according to this embodiment.

The flow rate of the cooling water circulated between the conventional cooling water circulation device 60 and the cooling water circulation device 50 according to the present embodiment was calculated and compared.

Here, it is assumed that the cooling water circulation device 50 circulates the cooling water in a series flow. Then, the circulation amount of the cooling water is calculated as follows, separately from the processing of the above steps S1 to S3.

First, a target temperature when the high heat generation density load 1 is cooled is set. Here, it is assumed that the temperature of the cooling water before and after the heat exchange changes by 5 degrees by exchanging heat with the high heat generation density load 1. Then, the flow rate of the cooling water in this case is calculated. That is, with ΔT ₁ =5 degrees, Q ₁ =3.71 m ³ /h/m ² is calculated by the equation (1). Since the cooling water is circulated by the series flow, the circulation flow rate Q ₀ of the cooling water circulated by the cooling water circulation device 50 is 3.71 m ³ /h/m ² .

Here, when the temperature T ₀ measured by the thermometer 9 is 25 degrees, the temperature T _{1_O of the} cooling water that flows out by exchanging heat with the high heat generation density load 1 by circulating the above flow rate is, for example, It was confirmed whether it would be 40 degrees or less. Since the cooling water circulation device 50 circulates the cooling water according to the series flow, the temperature T ₃ — _i =T ₀ =25 of the cooling water flowing into the low heat generation density load 3 is obtained. The flow rate Q ₃ of the low heat generation density load 3 and the cooling water heat exchanger is equal to Q _1. Therefore, from the equation (1), the temperature T 3 — _O of the cooling water that exchanges heat with the low heat generation density load 3 and flows out is calculated to be 26.6 degrees. Similarly, from the equation (1) and the relationship of T ₂ — _i =T 3 _—O =26.6 and Q ₂ =Q ₁ , the temperature T 2 _—O of the cooling water that flows out through heat exchange with the intermediate heat generation density load 2 is 30. Calculated as 0 degrees. Similarly, from the equation (1) and the relationship of T ₁ — _i =T 2 _—O =30.0, the temperature T 1 _—O of the cooling water that flows out through heat exchange with the high heat density load 1 is calculated to be 35.0 degrees. ..

That is, when the cooling water is circulated to each load by the series flow according to the present embodiment, the circulation amount of the cooling water is 3.71 m ³ /h/m ² . Even with such a circulation amount, when the temperature of the cooling water pumped from the pump 5 is 25 degrees, the temperature of the high heat generation density load 1 is decreased by 5 degrees, and the heat generation density The temperature of the cooling water that is exchanged and flows out is 40 degrees or less.

On the other hand, in the circulation method in the conventional cooling water circulation device 60, if ΔT ₁ =ΔT ₂ =ΔT ₃ =5 degrees, the flow rate of the cooling water required for heat exchange with each load is Q It is calculated as ₁ =3.71 m ³ /h/m ² , Q ₂ =2.32 m ³ /h/m ² , and Q ₃ =1.16 m ³ /h/m ² . Therefore, the circulation flow rate of the cooling water circulated by the cooling water circulation device 60 becomes Q ₀ =Q ₁ +Q ₂ +Q ₃ =6.19 m ³ /h/m ² .

<Action/effect>
With the cooling water circulation device 50 as described above, the cooling water can be made to flow in the order of the low heat generation density load 3, the medium heat generation density load 2, and the high heat generation density load 1 by the series flow to exchange heat with each load. .. Further, in the case of the cooling water circulation device 50 as described above, the cooling water is caused to flow into the high heat generation density load 1 through the mixing flow without passing through the loads other than the high heat generation density load 1 among the three loads, It is also possible to exchange heat with the high heat generation density load 1.

Here, as a result of comparing the flow rate with the conventional cooling water circulation device 60, in the case of the series flow by the cooling water circulation device 50 as described above, when the temperature of the cooling water pumped from the pump 5 is 25 degrees, the cooling water is It is possible to effectively cool the high heat generation density load 1 even when the circulation flow rate is 3.71 m ³ /h/m ² . On the other hand, in the conventional cooling water circulation device 60, the circulation flow rate of the cooling water was calculated to be about 6.19 m ³ /h/m ² . That is, in the series flow of the cooling water circulation device 50 as described above, for example, the cooling water that has exchanged heat with the medium heat generation density load 2 can be used for cooling the high heat generation density load 1, so that the flow rate of the cooling water is reduced. It Further, when the temperature measured by the thermometer 9 is 25 degrees, the flow rate of the cooling water can be reduced as much as possible, as compared with the conventional cooling water circulation device 60 that separately supplies the cooling water to each load. confirmed.

Further, the cooling water circulation device 50 described above can circulate the cooling water by a mixing flow. Here, when the temperature measured by the thermometer 9 is higher than 25 degrees, if the cooling water is circulated only by the series flow, the temperature of the cooling water flowing into the middle heat generation density load 2 will set the high heat generation density load 1 to a predetermined value. The temperature may be difficult to cool. Therefore, it may be necessary to increase the flow rate of the cooling water flowing into the middle heat generation density load 2. However, in the cooling water circulation device 50 as described above, the cooling water can be circulated in the mixing flow including the circulation in the series flow. That is, the cooling water that has not flowed into any of the loads and the cooling water that has flowed into the medium heat generation density load 2 are mixed, and the mixed cooling water is caused to flow into the high heat generation density load 1. It is possible to exchange heat with the high heat generation density load 1. Therefore, the increase in the flow rate of the cooling water flowing into the medium heat generation density load 2 is suppressed. Therefore, even when the temperature measured by the thermometer 9 rises, compared to the case where the cooling water is circulated only by the series flow, the increase in the flow rate of the cooling water is suppressed, and the load is cooled as specified. To be done.

Further, when calculating the flow rate in the mixing flow of the cooling water circulation device 50, as shown in FIG. 7 to FIG. 9, the flow rate Q ₁ ≧the medium heat density load passing through the high heat density load 1 as much as possible. Q ₁ , Q ₂ , and Q ₃ are repeatedly calculated so that the flow rate Q ₂ passing through ₂ ≧the flow rate Q ₃ passing through the low heat generation density load 3. Therefore, for example, Q ₁ <Q ₂ , and it is possible that part of the cooling water that has exchanged heat with the medium heat generation density load 2 and flows out returns to the cooling device 4 without passing through the high heat generation density load 1. Is reduced to.

Further, in the above-described method of calculating the flow rate in the mixing flow of the cooling water circulation device 50, the flow rate Q _{1 of the} cooling water that exchanges heat with the high heat generation density load 1 in the mixing flow is calculated according to the heat generation load density of each load. In some cases, the constraint conditions and the like may be changed as appropriate, and the flow rate Q ₁ may be calculated so as to be greater than or equal to the flow rate Q ₂ .

That is, even if the temperature measured by the thermometer 9 is higher than 25 degrees, the cooling water circulation device 50 can reduce the increase in the flow rate of the cooling water as much as possible while keeping each load at a predetermined level. Can be street cooled.

In addition, if the cooling water circulation device 50 as described above is used, the series flow and the mixing flow are selectively used in accordance with the temperature measured by the thermometer 9 to reduce the flow rate of the cooling water as much as possible, while reducing the load. Can be cooled as desired. Therefore, the cooling water circulation device 50 is a highly convenient device.

Further, in the case of the cooling water circulation device 50, the circulation flow rate Q ₀ circulated in the series flow becomes a value equal to or higher than the minimum flow. Therefore, the influence on the operation of the pump 5 is suppressed. Further, in the mixing flow, since the flow rate of the series flow or more flows, the circulation flow rate Q ₀ becomes the value of the minimum flow or more in the mixing flow as well. Therefore, the influence of the operation of the pump 5 is suppressed even in the mixing flow.

Further, with the cooling water circulation device 50 as described above, even if the temperature of the cooling water is higher than 25 degrees, the cooling water can be used for cooling each load. Therefore, the cooling water stored in the cooling tower used by the cooling device 4 can be circulated to each load, and the power of the cooling device 4 can be saved.

<Modification>
FIG. 10 shows an example of an outline of the cooling water circulation device 50A. The difference between the cooling water circulation device 50 according to the present embodiment and the cooling water circulation device 50A is that in the case of the cooling water circulation device 50A, the cooling water is circulated to two loads, a high heat density load 1 and a medium heat density load 2. is there.

Even with such a cooling water circulation device 50A, the series flow and the mixing flow are realized. Further, the flow rate of the cooling water in the series flow is calculated as in the processing flow shown in FIG. Further, as in the processing flow shown in FIG. 5, the flow rate of cooling water in the mixing flow is calculated. However, in the process flow shown in FIG. 5, the calculation of the flow rate passing through the low heat generation density load 3 (step S10) may not be performed.

Further, the cooling water circulation device 50A circulates the cooling water to the two loads of the high heat density load 1 and the medium heat density load 2, but cools it to the two loads of the medium heat density load 2 and the low heat density load 3. Water may be circulated. Further, the cooling water circulation device 50A may circulate the cooling water to two loads, the high heat generation density load 1 and the low heat generation density load 3.

Further, FIG. 11 shows an example of an outline of the cooling water circulation device 50B. In the cooling water circulation device 50B, the control device 10 controls to open the valve provided at the inlet of the three-way valve 6A on the side of the branch pipe 21. Further, the control device 10 controls to open a valve provided at the inlet of the three-way valve 6A on the side of the circulation pipe 20. Further, the control device 10 controls to close the valve provided at the inlet of the three-way valve 6B on the side of the branch pipe 22. Further, the control device 10 controls to open the valve provided at the inlet of the three-way valve 6B on the circulation pipe 20 side. That is, the cooling water circulation device 50B makes a series flow when circulating the cooling water from the low heat generation density load 3 to the medium heat generation density load 2, and circulates the cooling water from the medium heat generation density load 2 to the high heat generation density load 1. In some cases, it has a mixing flow.

Even the circulation device according to the modified example as described above can achieve the same effect as that of the cooling water circulation device 50 according to the present embodiment.

Further, in the above embodiment, the number of loads is three, but the number of loads may be any number as long as it is two or more. The load density of each load is not limited to the values exemplified in the above embodiment, and the load density of each load may be the same. Further, the temperature of the cooling target portion of each load may be the same.

Although an example of the preferred embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the idea described in the claims, and naturally, they also belong to the technical scope of the present invention. Understood. Further, the embodiments and modifications disclosed above can be combined with each other.

1: High heat density load 2: Medium heat density load 3: Low heat density load 4: Cooling device 5: Pump 6A: Three-way valve 6B: Three-way valve 7: Valve 8A: Pump 8B: Pump 9: Thermometer 10: Controller 11: Valve 20: Circulation pipe 21: Branch pipe 22: Branch pipe 50: Cooling water circulation device 50A: Cooling water circulation device 50B: Cooling water circulation device 51A: Valve 51B: Valve 60: Cooling water circulation device

Claims (8)

A pumping means for pumping cooling water for cooling a plurality of loads,
Adjusting means for adjusting the flow rate of the cooling water that is pressure-fed by the pressure-feeding means and that flows into the first load and the second load of the plurality of loads,
The temperature of the cooling target of the second load that exchanges heat with cooling water is equal to or higher than the temperature of the cooling target of the first load that exchanges heat with cooling water,
The adjusting means is pressure-fed by the pressure-feeding means and is flowed by the pressure-feeding means, and a flow rate of cooling water that is flown into the second load without flowing into any of the plurality of loads. Adjusting the flow rate of the cooling water flowing into the second load via the first load,
Cooling system. Mixing in which cooling water pumped by the pumping means and not flowing into any of the plurality of loads and cooling water pumped by the pumping means and flowing into the first load are mixed Further provided,
The adjusting means adjusts a flow rate of cooling water to be mixed in the mixing section, and sends the adjusted cooling water to the second load.
The cooling system according to claim 1. When the temperature of the cooling water pressure-fed by the pressure-feeding unit is equal to or lower than a predetermined temperature, the adjusting unit pressure-feeds the pressure-feeding unit by the pressure-feeding unit in the mixing section and flows into any of the plurality of loads. Cooling water that has not been mixed is not mixed with the cooling water that has been pumped by the pumping means and that has flowed into the first load.
The cooling system according to claim 2. When the temperature of the cooling water pumped by the pumping means is higher than a predetermined temperature, the adjusting means is pumped by the pumping means and flows into any one of the plurality of loads in the mixing section. Mixing the cooling water that has not been supplied with the cooling water that has been pumped by the pumping means and that has flowed into the first load.
The cooling system according to claim 2 or 3. The pumping means is a pump,
The pumping means is a flow rate capable of cooling the load having the highest temperature of the cooling target that exchanges heat with the cooling water among the plurality of loads to a second predetermined temperature, and is a minimum flow of the pump or more. Pumping cooling water at a flow rate of
The cooling system according to claim 3. There are three loads,
Cooling water that has been pumped by the pumping means and has not flowed into any of the plurality of loads, and cooling water that has been pumped by the pumping means and that has flowed into the first load or the second load. Further comprising a second mixing section for mixing
The adjusting means adjusts a flow rate of cooling water to be mixed in the second mixing section, and sends the adjusted cooling water to a third load of the plurality of loads,
The temperature of the cooling target of the third load that exchanges heat with cooling water is equal to or higher than the temperature of the cooling target of the second load that exchanges heat with cooling water.
The cooling system according to any one of claims 2 to 5. A pumping step of pumping cooling water for cooling a plurality of loads,
And a step of adjusting the flow rate of the cooling water that is pressure-fed in the pressure-feeding step and that flows into the first load and the second load of the plurality of loads,
The temperature of the cooling target of the second load that exchanges heat with cooling water is equal to or higher than the temperature of the cooling target of the first load that exchanges heat with cooling water,
The adjusting step is pressure-fed in the pressure-feeding step, and is flowed in the pressure-feeding step with a flow rate of cooling water flowing into the second load without flowing into any load of the plurality of loads, and Adjusting the flow rate of the cooling water flowing into the second load via the first load,
Cooling method. According to the heat generation amount per unit area of the cooling target of the first load, and the heat generation amount per unit area of the cooling target of the second load, the flow rate of the cooling water flowing into the second load, The method further includes a calculation step of repeatedly calculating the flow rate of the cooling water flowing into the second load so as to be equal to or higher than the flow rate of the cooling water flowing into the first load.
The cooling method according to claim 7.

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