JPH05143169A - Start controlling method for water cooling device - Google Patents

Abstract

PURPOSE:To prevent the generation of dew condensation on a cooled body at the time of starting a water cooling device without using a dew condensation preventing additional device such as a heater. CONSTITUTION:When the temperature of cooling water is less than a prescribed value in a closed loop consisting of a water/water heat exchanger 1, a mixing three-way valve 2, a cooled body 3, a pump 4, and a by-pass 5 for the heat exchange, the flow rate of the by-pass 5 is increased, the inflow of water into the heat exchanger 1 is restricted for a prescribed time to suppress the temperature drop of cooling water in the closed loop and prevent the generation of dew condensation on the cooled body 3, and when the temperature of the cooling water reaches a prescribed temperature range, water temperature control for a normal state is started. Even when water temperature of the closed loop is low, the temperature drop of the cooling water in the heat exchanger 1 at the time of starting the water cooling device can be suppressed to its minimum and the generation of dew condensation on the cooled body 3 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a start control method for a water cooling device, and more particularly, to a water cooling system for cooling an electronic device such as a large computer which is accompanied by heat generation. The present invention relates to a start control method for a device.

[0002]

2. Description of the Related Art When starting the water cooling device, if the temperature of the cold water sent out from the water cooling device drops, dew condensation may occur inside the electronic equipment which is the object to be cooled. This dew condensation adversely affects electronic devices and circuits and may cause a failure.

As a means for preventing dew condensation, a method of comparing the dew point temperature calculated from the detected temperature and humidity with the cooling water temperature and heating with a heater so that the cooling water temperature does not fall below the dew point temperature (Japanese Patent Laid-Open No. 62-62). -139015), a temperature sensor, a condensation sensor, a drying fan, a heater, etc., and immediately turn on the power to the electronic device if there is no condensation, but if there is condensation, heat it with the heater to eliminate condensation. There is a method of turning on the power supply of the electronic device at the time (Japanese Patent Application Laid-Open No. 62-119621).

[0004]

The water cooling device is basically a water-water heat exchanger for exchanging heat between cooling water from an external cooling water facility and water heated by the object to be cooled. A mixing three-way valve for mixing water cooled by this heat exchanger and water bypassing the heat exchanger, a motor for driving the mixing three-way valve to change its opening, and a mixing three-way valve. And a pump for circulating water in a closed loop formed between the water-water heat exchanger and the object to be cooled.

At the time of starting the water cooling device having such a system configuration, at least three parameters, that is, the opening degree of the mixing three-way valve, the temperature of the cooling water sent from the cooling water facility side, and the water temperature returned from the object to be cooled are satisfied. Since the opening degree of the mixing three-way valve becomes indefinite, the temperature of cold water sent from the water cooling device becomes unstable. Particularly, when the cooling water temperature on the cooling water facility side is low, low-temperature cold water may be supplied to the object to be cooled, and dew condensation may occur on the object to be cooled such as electronic equipment.

[0006] In each of the above-mentioned conventional methods, there is a problem in that a heater for heating is originally provided in the device for cooling, but there is a drawback that the structure of the device, the control method, and the configuration of the controller for executing the device are complicated. there were.

An object of the present invention is to provide a water cooling system capable of reliably preventing dew condensation on a cooled object at the time of start-up only by controlling the opening degree of a mixing three-way valve without adding a device such as a heater to prevent dew condensation. A starting control method for an apparatus is provided.

[0008]

In order to achieve the above object, the present invention is a water-water heat exchanger for exchanging heat between cooling water from an external cooling water facility and water heated by an object to be cooled. And a mixing three-way valve that mixes water cooled by this heat exchanger with water that bypasses the heat exchanger, and a water-water heat exchanger and a cooled object with a mixing three-way valve interposed. It is composed of a pump that circulates water in a closed loop, and controls the opening of the mixing three-way valve based on the detected water temperature of the cold water sent to the object to be cooled and starts the water cooling device that supplies the cold water of a predetermined water temperature to the object to be cooled. In the control method, when starting the water cooling device,
If the water temperature of the cold water sent from the water-water heat exchanger to the object to be cooled is lower than the predetermined width based on the set water temperature, the water-water heat exchanger side flow path of the mixing three-way valve is temporarily throttled for a predetermined time, The present invention proposes a start control method for a water cooling device that raises the temperature of cold water sent to an object to be cooled to within a predetermined range and then shifts to steady-state water temperature control.

The bypass and the mixing three-way valve are provided not on the closed loop side formed between the water-water heat exchanger and the object to be cooled but on the cooling water facility side outside the water-water heat exchanger. Even when the water cooling device is installed, water-
If the temperature of the cold water sent from the water heat exchanger to the object to be cooled is lower than the specified width based on the set water temperature, the flow path on the water-water heat exchanger side of the mixing three-way valve is temporarily throttled for the specified time and cooled. It is possible to employ a start control method of the water cooling device in which the water temperature of the cold water sent to the body is raised to within a predetermined range and then the water temperature control in the steady state is performed.

[0010]

When the temperature of the cold water sent from the water-water heat exchanger to the object to be cooled is lower than the predetermined width based on the set water temperature when the water cooling device is started, the water-water heat exchanger of the mixed three-way valve is used. The side flow path is once narrowed to the minimum, the heat exchange amount of the water-water heat exchanger is minimized, and the water temperature sent to the object to be cooled is not lowered as much as possible. By this operation, the cold water sent to the object to be cooled starts to rise from the temperature at the time of start-up and rises toward the set water temperature, so the stability of the water temperature is improved and, of course, it is better than the set value. Cold water having an extremely low temperature will not be supplied to the object to be cooled. Therefore, it is possible to reliably prevent dew condensation on the cooled object.

When the temperature of the cold water sent out from the water-water heat exchanger to the object to be cooled is within a predetermined range based on the set water temperature, and when it is higher than the predetermined range higher than the set value, Since there is no concern about dew condensation, normal water temperature control is executed as in the conventional case. It goes without saying that the width of the predetermined value above and below the set value does not necessarily have to be the same.

[0012]

EXAMPLES Examples of the present invention will now be described with reference to FIGS. FIG. 1 is a diagram showing an example of a system configuration of a water cooling device to which the starting control method according to the present invention is applied.
The water cooling device surrounded by the chain double-dashed line is basically a water-water heat exchanger 1 for exchanging heat between the cooling water from an external cooling water facility (not shown) and the water of this device; A mixing three-way valve 2 for mixing water cooled by the water heat exchanger 1 and water heated by the object to be cooled 3, a motor 6 for driving the mixing three-way valve 2, and a water mixture with the mixing three-way valve 2 interposed. A pump 4 for circulating water in a closed loop formed between the water heat exchanger 1 and the body 3 to be cooled. That is, the pump 4
Circulates cold water in a closed loop of the water-water heat exchanger 1, the mixing three-way valve 2 and the body to be cooled 3. Here, the object to be cooled is, for example, an electronic device such as a computer that has increased heat generation due to high integration of semiconductors and the like.

A bypass passage 5 is provided in parallel with the water-water heat exchanger 1.
Is provided, and the flow rate ratio between the water-water heat exchanger 1 and the bypass passage 5 is determined by the change in the opening degree of the mixing three-way valve 2. The motor 6 that drives the mixed three-way valve 1 is a reversible rotation type motor, and two types of drive signals from the controller 8 cause
Forward or reverse. When the normal rotation side is energized, the flow rate on the water-water heat exchanger 1 side increases and the flow rate on the bypass flow path 5 side decreases. On the other hand, when the reverse rotation side is energized, contrary to the forward rotation,
The flow rate on the water-water heat exchanger 1 side decreases and the flow rate on the bypass flow path 5 side increases. The closed loop flow rate is the total flow rate of the water-water heat exchanger 1 side flow rate and the bypass flow path 5 side flow rate,
It is constant regardless of the opening degree of the mixing three-way valve 2.
A water temperature detection sensor 7 is provided in the flow passage from the water cooling device to the cooled body 3. The controller 8 drives the mixing three-way valve drive motor 6 in order to control the opening degree of the mixing three-way valve 2 according to the difference between the detected water temperature and the set water temperature. In addition, a signal indicating whether or not the cooling target 3 can be started is sent according to the difference between the detected water temperature and the set water temperature.

When the pump 4 is started during steady operation in which the water temperature of the cold water is stable, the water warmed while passing through the body to be cooled 3 is sent to the water-water heat exchanger 1 and the bypass passage 5. The water cooled by the cooling water from the cooling water facility in the water-water heat exchanger 1 and the warm water simply passing through the bypass flow path are agitated by the mixing three-way valve 2 and sent to the cooled object 6. If the ratio of the water passing through the cooling water facility and the water passing through the bypass flow passage is changed to circulate in the closed loop, cold water having a constant temperature is always supplied to the cooled body 3.

On the other hand, at the time of starting, a. Water temperature is not stably supplied from the cooling water facility b. The temperature of the water supplied from outside to the cooling water facility differs depending on the customer's environment. C. The heat load of the cooled object is also in the transient region at the time of starting d. Due to the reason that the opening degree of the mixing three-way valve is in the position of the stable control state during the previous operation, it cannot be expected that cold water close to the set water temperature is stably supplied to the cooled body 3. In particular, when the temperature of the water supplied from the outside to the cooling water facility is low, or when the opening of the mixing three-way valve 2 on the water-water heat exchanger 1 side is large and the amount of heat exchange is large, the cooling target 3 is The temperature of the water to be sent becomes extremely lower than the set water temperature, the rise to the set water temperature is delayed, and there is a risk that dew condensation will occur on the cooled body 3 and damage the cooled body 3.

Therefore, at the time of starting, the control shown in the flowchart of FIG. 2 is executed. In step 10,
The pump 4 is started, and in step 12, the mixing three-way valve drive motor 6 is reversely rotated for a predetermined time t ₁ . Due to the reverse rotation of the mixing three-way valve 2, the flow rate of cold water on the water-water heat exchanger 1 side decreases and the flow rate of cold water on the bypass flow path 5 side increases. Therefore, the amount of heat exchange between the cooling water supplied from the cooling water facility in the water-water heat exchanger 1 and the cold water in the closed loop gradually decreases. When the flow rate through the water-water heat exchanger 1 becomes zero, the heat exchange amount also becomes zero, and in the cold water in the closed loop, the heat generated by the pump 4 and the transient until the mixing three-way valve 2 is fully closed. Since there is only heat dissipation, the cooled object 3
The temperature of the chilled water supplied to the unit does not decrease from the start. Here, the predetermined time t ₁ for energizing the mixing three-way valve drive motor 6 is the time until the mixing three-way valve 2 changes from the fully open position to the fully closed position, or the calorific value even if the mixed three-way valve 2 is not in the fully closed state. And the amount of heat radiation are determined based on the time required to reach the degree of opening where dew condensation does not occur on the cooled body 3.

At step 14, it is judged whether or not a predetermined time t ₁ has elapsed. After the lapse of time, in step 16, the mixing three-way valve drive motor 6 is temporarily stopped. In step 18, the sending water temperature Tw to the cooled body 3 is detected. In step 20, Tw is the water temperature set value Twse
If it is within a certain range (-ΔT) from t, that is, Tw
If it is equal to or more than set-ΔT, the water temperature control in the steady state is performed.

On the other hand, if it is lower than Twset-ΔT, in step 22, the mixing three-way valve drive motor 6 is further driven to the reverse rotation side to reduce the amount of heat exchange with the water-water heat exchanger 1 and to cool water. Make the water temperature rise faster. Step 1 again
At 8, the sending water temperature Tw to the cooled body 3 is detected.
In step 20, if the water temperature Tw is equal to or higher than Twset-ΔT, the control proceeds to steady-state water temperature control.

At this time, in order to accelerate the rise of the temperature of the cold water, the body to be cooled 3 can be operated to generate heat. Further, in the above-described embodiment, the mixing three-way valve drive motor 6 is driven to the reverse rotation side at the same time as the pump 4 is driven, but the reverse rotation operation for the predetermined time t ₁ is completed before the pump 4 is started. Good.

FIG. 3 shows the water temperature T in the closed loop during the above operation.
It is a time chart which shows the change over time of w. Curve A is
It shows a case where the water temperature Tw is a low temperature start requiring the start control of the present invention. The curve B shows the case where the water temperature Tw is within ± ΔT with respect to the set water temperature Twset, and the water temperature control in the steady state can be immediately started. Curve C is the water temperature T
w is higher than + ΔT with respect to the set water temperature Twset,
The figure shows a case where the water temperature control in the steady state must be started when the cooling is performed from the start and the temperature is within ± ΔT with respect to the set water temperature Twset.

In the present embodiment, after the start, a predetermined time t
_By rotating the mixing three-way valve drive motor 6 by ₁ only, the amount of heat exchange in the water-water heat exchanger 1 is reduced, and a decrease in the temperature of the water delivered to the cooled object 3 is almost prevented. If this operation does not occur and the temperature of the water supplied from the cooling water facility side is low, the temperature of the water sent to the cooled body 3 is extremely lowered as shown by the broken line in FIG. Occurs.

According to the present embodiment, not only the dew condensation on the cooled body 3 is prevented, but also the water temperature controllability at the time of shifting to the control in the steady state is improved, and the set water temperature is overshooted or undershot with respect to Twset. There are also few shots, and the effect of quick convergence can be obtained.

In the above embodiment, an example in which the present invention is applied to an apparatus configuration in which the bypass flow path 5 and the mixing three-way valve 2 are provided on the closed loop side has been described. However, as shown in FIG.
It can be easily understood that the present invention is effective even when the bypass passage 5A, the mixing three-way valve 2A, and the mixing three-way valve drive motor 6A are arranged on the cooling water facility side of the water heat exchanger 1. ..

[0024]

According to the present invention, when the temperature of the cold water in the closed loop is low, the mixing three-way valve drive motor is reversed for a predetermined time t ₁ after the start, and the heat exchange amount in the water-water heat exchanger is reduced. Only by doing so, it is possible to almost prevent the temperature of the water to be sent to the cooled object from decreasing. Therefore, it is possible to reliably prevent the dew condensation of the cooled object at the time of starting the water cooling device without adding any dew condensation preventing device.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a system configuration of a water cooling device to which a starting control method according to the present invention is applied.

FIG. 2 is a flowchart illustrating the operation of the embodiment of FIG.

FIG. 3 is a time chart showing the change over time in the water temperature in the closed loop during the operation of FIG.

FIG. 4 is a diagram showing another example of the system configuration of the water cooling device to which the starting control method according to the present invention is applied.

[Explanation of symbols]

 1 Water-water heat exchanger 2 Mixed three-way valve 3 Cooled body 4 Pump 5 Bypass 6 Mixed three-way valve drive motor 7 Water temperature detection sensor 8 Controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Komaki 390 Muramatsu, Shimizu City Shizuoka Prefecture, Hitachi Shimizu Plant (72) Inventor Katsushi Mitsui 390 Muramatsu Shimizu City Shizuoka Prefecture Hitachi, Ltd. Shimizu Plant, Ltd. (72) Inventor Tetsuji Yamashita 390 Muramatsu, Shimizu City, Shizuoka Hitachi, Ltd. Shimizu Plant (72) Inventor Kashiro Murakami 390 Muramatsu, Shimizu City, Shizuoka Hitachi Ltd. Shimizu Plant

Claims (2)

[Claims] 1. A water-water heat exchanger for exchanging heat between cooling water from an external cooling water facility and water heated by an object to be cooled, and water cooled by the heat exchanger and the heat exchanger. A mixing three-way valve for mixing with water bypassed, and a pump for circulating water in a closed loop formed between the water-water heat exchanger and the body to be cooled with the mixing three-way valve interposed. In the starting control method of the water cooling device that controls the opening degree of the mixing three-way valve based on the detected water temperature of the cold water sent to the cooled object and supplies the cold water of a predetermined water temperature to the cooled object, At the time of start-up, if the water temperature of the cold water sent from the water-water heat exchanger to the object to be cooled is lower than a predetermined width based on the set water temperature, the water-water heat exchanger side flow path of the mixing three-way valve Squeezed for a predetermined time and sent to the object to be cooled. Cold water temperature is increased to within the predetermined range, the start control method for subsequently moving to the water temperature control during steady water cooler, characterized in issue. 2. A water-water heat exchanger for exchanging heat between cooling water from an external cooling water facility and water, cooling water for cooling the heat exchanger, and cooling water for bypassing the heat exchanger. It consists of a mixing three-way valve for mixing on the side of the external cooling water facility and a pump for circulating water in a closed loop formed between the water-water heat exchanger and the object to be cooled, and sends it to the object to be cooled. In a start control method of a water cooling device that controls the opening degree of the mixing three-way valve based on the detected water temperature of cold water to supply cold water of a constant water temperature to the cooled object, at the time of starting the water cooling device, the water-water When the water temperature of the cold water sent from the heat exchanger to the cooled object is lower than the predetermined width based on the set water temperature, the water-water heat exchanger side flow path of the mixing three-way valve is temporarily throttled for a predetermined time, The temperature of the cold water sent to the cooled object is set to the predetermined range. It is raised to the inner, starting control method for subsequently moving to the water temperature control during steady water cooling apparatus according to claim.