JP2000207001A - Heater control method, heater controller and cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable temperature control according to heater control with fine resolution by using output obtained by using half cycle power unit of the alternating current power supply of a cycle control unit a unit. SOLUTION: A total availability factor calculating part 2 calculates the total availability factor in a fixed period based on a detected temperature and a set temperature in every fixed period, an availability factor reading part 3 successively reads the ordered set of a time division availability factor in a fixed period which corresponds to the total availability factor calculated from a time division table 4 in every time division cycle and transfers an availability factor signal of the read time division cycle to a cycle control unit 5, and the unit 5 feeds power to a heater 6 according to the availability factor of the time division cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater for controlling the temperature of cooling water of an electronic device, in particular, a cooling device for a large-sized computer, in order to keep the temperature of the cooling water constant and to prevent the cooling water from freezing. And a heater control device and a cooling device.

[0002]

2. Description of the Related Art A conventional cooling system for a large computer uses a heater to prevent freezing of cooling water. This is because the refrigerant temperature control of the refrigerator module is performed only by the ON / OFF control of the compressor, so that the cooling load is "too cold" (when the load is smaller than an expected value). ) Occurs, the temperature control cannot respond quickly, and the cooling water may reach the freezing temperature. Therefore, a heater is installed in the cooling water tank, and while monitoring the temperature of the cooling water to the cooling load, heating is controlled by the heater so as to prevent freezing of the cooling water and maintain the temperature within a range where the cooling load is cooled. Thus, the temperature of the cooling water was adjusted.

FIG. 6 is a diagram for explaining heater control in a cooling system for electronic equipment. Reference numeral 56 denotes a refrigerator module which is a refrigerant containing Freon gas and can be cooled to -30 ° C.
7 is a compressor, 58 is a pipe for circulating the refrigerant in the direction of the arrow, 59 is a condenser, 60 is an evaporator, 61 is a heat exchanger, 62 is a pipe for circulating the cooling water cooled by the heat exchanger 61 in the direction of the arrow, 63 is a pipe. Cooling load (for example, CPU of a large computer), 64 is a tank for temporarily storing cooling water,
65 is a flow sensor, 66 is a valve, 67 is a pump, 68
Is a freezing prevention sensor, 69 is a heater control device, 70 is a temperature sensor, and 71 is a heater.

The refrigerator module 56 detects the temperature of the cooling water in the cooling loop and controls the temperature at the inlet of the primary side of the heat exchanger 61 to be close to 0 ° C. When the temperature of the cooling water in the cooling loop decreases, the temperature of the refrigerant in the refrigerator system decreases, so that the temperature of the cooling water further decreases, the secondary side of the heat exchanger 61 freezes, and the cooling loop operates. There is a possibility of disappearing. Therefore, the heater control device 69 detects the temperature decrease tendency of the cooling load inlet by the temperature sensor 70, heats the cooling water in the tank 64 installed on the cooling load output side by the heater 71, and reduces the temperature of the cooling water. adjust.

[0005] The tank 64 is provided for checking the amount of water in a pipe for circulating cooling water at a water level level and also for adjusting the temperature of water entering the heat exchanger to prevent freezing. The anti-freezing sensor 68 detects the temperature of cooling water in the heat exchanger 51 and controls the compressor 57 to prevent freezing. The two flow sensors 65, two valves 66, and two pumps 67 are provided to provide redundancy in case of failure of the pump 67.

A conventional heater control in the cooling system shown in FIG. 6 will be described with reference to FIGS. Large computers generally need to avoid high frequency noise. For this reason, cycle control for supplying electric power to the heater in synchronization with the AC power supply in half cycle units of the AC power supply is applied to the heater control device.

FIG. 7 is a diagram for explaining the outline of a conventional heater control device. 75 is a temperature control unit, and 76 is a cycle control unit for supplying electric power to the heater. As shown in FIG. 6, the temperature sensor 70 is installed at a location separated from the heater 71, and the temperature process control has a large time lag. Therefore, the temperature control unit 75 performs sampling control for PID adjustment. The PID parameters and the sampling time are designed to optimize the control system. Temperature controller 75
Detects the temperature of the cooling water at a sampling interval of, for example, 2 seconds, performs a PID calculation, and converts the calculation result into a signal indicating the operation rate of the cycle control unit (the rate of supplying power to the load in the control cycle). And outputs it to the cycle control unit 76. The cycle control unit 76 supplies electric power to the heater according to the input operation rate, and heats the cooling water.

The circuit of the cycle control unit 76 is shown in FIG.
(A). 81 is a cycle control circuit, 82 is a switch circuit for turning on / off an AC commercial power supply, 83 is a transformer,
84 is an input terminal for inputting an operation rate setting signal which is an output signal of the temperature control unit 75, 85 is a power supply terminal, and 86 is a heater connection terminal.

Next, the operation of the cycle control unit 76 will be described. The cycle control unit 76 controls the on / off of the AC power supply in synchronism with the zero crossing voltage point in units of a change amount of a half cycle (the resolution is 5% at 50 cycles) with respect to the input signal indicating the operation rate. And a device for supplying a predetermined power to the load. The on / off control of the AC power supply at the time of the zero cross voltage of the AC power supply is to prevent high frequency noise generated by the cutting voltage from adversely affecting the electronic device.

[0010] AC power supply 50 cycles, control cycle 0.2
FIG. 8C shows the output of the cycle control unit in the case of seconds (10 cycles of the AC power supply). 100%, 75%, 50 operating rate per control cycle of cycle control unit 76
FIG. 8C shows an output voltage when an input signal indicating%, 25%, or 0% is input to the cycle control unit 76.

The cycle control circuit 81 is a circuit for converting an input signal which is an operation setting signal into a time width signal, and this time width signal is output as a conduction control signal of the switch circuit 82. The conduction control signal changes in units of a half cycle width of the AC power supply and is synchronized with the AC power supply. Cycle control circuit 8
Reference numeral 1 denotes a circuit for decoding an input signal which is an operation rate setting signal, such as a decoder, a register, and a counter. The counter of the cycle control circuit is preset at a control cycle of 0.2 seconds synchronized with the AC power supply. The operation rate of the cycle control unit 76 is 100%, 75%, 50%, 25%,
FIG. 8B shows a conduction control signal of the switch circuit 82 when an input signal designating 0% is input. FIG. 8 (a)
In the circuit of the cycle control unit 76, the switch circuit 82 is provided on the primary side of the transformer 83, but may be provided on the secondary side instead of the primary side of the transformer 83.

[0012]

In the case of a large-scale computer system using a CMOS or the like, the operation is performed while cooling the CMOS LSI. To operate a CMOS LSI at high speed, it is necessary to cool it to a low temperature. But,
When the temperature is set low, freezing of the cooling water is more feared. When high-speed calculation and prevention of freezing of cooling water are required, the operating range must be reduced.

The set value of the temperature adjustment by the heater control is as follows:
For example, the temperature is set at 10 to 20 ° C to 5 to 8 ° C.
Therefore, it is necessary to finely control the temperature by controlling the heater. However, in the current temperature control using the cycle control unit, the operation rate is changed in a unit of a half cycle of the AC power supply voltage, and there is a problem that the temperature cannot be controlled precisely.

In the temperature control, control for a large temperature change may be required. It is conceivable to use a large number of small heaters to cope with a large temperature change, but this increases the cost. Using a larger heater can cope with various temperature changes including a large temperature change than preparing a plurality of small ones. Conversely, control of a larger heater does not require the use of a smaller heater. It is desirable that a single heater can control both a large temperature change and a small temperature change.

It is an object of the present invention to provide a heater control method, a heater control device, and a cooling device which can use an output of a cycle control unit in units of a half cycle of an AC power supply and can control the temperature with fine resolution. With the goal.

[0016]

FIG. 1 is a diagram illustrating the principle of the present invention. FIG. 1A is a configuration diagram thereof. The overall operation rate calculation unit 2 calculates a control amount indicating the overall operation rate at regular intervals based on the temperature detected by the temperature sensor 1 and the temperature set value, and outputs a signal corresponding to this to the operation rate reading unit 3. Is input, and the operation rate reading unit 3 obtains an ordered set of the time division operation rates stored in the time division table using the obtained overall operation rates, and calculates the time division operation rate for each time division cycle. Read sequentially,
The read operation rate signal of the time division cycle is passed to the cycle control unit 5, and the cycle control unit supplies power to the heater 6 according to the operation rate of the time division cycle. FIG.
Exemplarily shows that the resolution of heater control can be improved by the present invention.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a configuration example of the heater control device of the present invention. 21 is a temperature controller, 22 is an encoder, 2
3 is a selector, 24 is a memory for storing control parameters (not shown) and a time-division table, and 24a is a time-division table.
Bull. Reference numeral 25 denotes a cycle control unit (same as 76 in FIG. 8) for supplying electric power to the heater 71.

FIG. 3 is an example of a time division table used in the present invention. The time-division table associates the overall operation rate in a predetermined cycle with an ordered set of operation rates in a control cycle.
In the table shown, the leftmost column corresponds to the overall operation rate, the next column controls the operation rate of the first control cycle, the next column controls the corresponding operation rate of the second control cycle, and so on. It corresponds to the operation rate of the cycle.

FIG. 3 shows an example in which the predetermined period is set to a sampling time of the control system of 2 seconds, and the period is divided into ten times at 0.2 seconds of the control period of the cycle control unit, and the operating rate is distributed. It is. The overall operation rate is determined by the P of the temperature control unit 21.
It corresponds to the ID calculation output, and is represented by an amount (%) corresponding to the operation rate of the cycle control unit. The time division cycle number in the figure indicates the order of the control cycle in the sampling cycle. For example, for the entire operation rate of 37.5%, the operation rates are 75%, 75%, 75%, 7
Signals of 5%, 75%, 0%, 0%, 0%, 0%, 0% are input signals for one sampling period in the cycle control unit.

The overall operation rate in FIG. 3 represents an average of the operation rates during one sampling period. In the example of FIG. 3, the resolution of the overall operation rate that can be handled is 2.5%, but a time-division table can be created so that the resolution of the overall operation rate is 2.5% or less.

The temperature control section 21 performs a PID calculation based on the detected temperature and the set temperature value. The encoder 22 converts the PID calculation output of the temperature control unit 21 into a corresponding overall operation rate. The selector 23 is an encoder.
A row of the time-sharing table corresponding to the overall operating rate passed from the coder 22 is obtained, the operating rate of the control cycle is read from the obtained row for each control cycle, and the read operating rate of the control cycle is stored in the cycle control unit 25. Pass to.

The operation of the heater control according to the present invention will be described with reference to the flow charts of FIGS. The heater control device is started by the start signal of step S1, and is turned on in step S1.
2 is performed. At this time, since the cooling load is still in the initial load state and the cooling system tends to be too cold, the heater temporarily heats the cooling water at an operation rate of 100%, and thereafter, when the cooling water approaches the set temperature, A release signal is output, and the set temperature control is started.

At the sampling time of step S3, the temperature control section 21 takes in the temperature detected by the temperature sensor 70 (step S4). If the temperature is equal to or lower than the set temperature of the cooling water in step S5, the heater is controlled to adjust the temperature. Then, a PID operation is performed (step S6). P
The ID calculation output is converted into a code signal indicating the overall operation rate by the encoder 22 and sent to the selector 23. If the detected temperature is equal to or higher than the set temperature in step S5, it is determined that temperature adjustment by heater control is not necessary, and temperature adjustment is not performed by heater control until the next sampling time.

The selector 23 reads the operation rate of the first time division cycle (control cycle) from the row corresponding to the overall operation rate in the time division table (step S7) and outputs it to the cycle control unit 25 (step S8). . The cycle control unit 25 supplies power to the heater 71 according to the input operation rate during the time division cycle.

When the time division period has elapsed (step S9) and the sampling period is within the period (step S11), the selector 23 reads the operation rate of the next time division period (step S12) and outputs it to the cycle control unit 25. (Step S8). This is repeated within the sampling period and output to the cycle control unit 25. At the sampling time, the temperature control unit 21 takes in the temperature detected by the temperature sensor 70 (step S4) and performs the same operation.

The heater control of the present invention is performed by the heater control device having the circuit shown in FIG.
A memory for storing control parameters and time-division tables,
It is also implemented by a control device constituted by a cycle control unit.

FIG. 5 shows an example of operation when the heater control of the present invention is applied. 51 is a cooling water temperature, 52 is a set temperature, 53 is a release signal permitting the set temperature control by the heater control of the present invention, 54 is a heater control output by the set temperature control, and 55 is a start of the set temperature control. It is time.

[0028]

According to the present invention, even if a cycle control unit for controlling the output of an AC power supply in half cycle units is used for heater control, one heater can control a large temperature change to a small temperature change. In addition, since the temperature can be adjusted even when the temperature of the cooling water is delicate, a CMOS LSI
It is possible to operate electronic devices, especially large-scale computer systems, which operate at high speed, and the heater control system eliminates unnecessary heat release and reduces power consumption. Further, a cycle control unit that can control the number of ON half-cycle units in a sampling cycle (for example, 2 seconds) becomes expensive, but the present invention can use an inexpensive cycle control unit, thereby reducing manufacturing costs.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a configuration example of a heater control device.

FIG. 3 shows an example of a time division table.

FIG. 4 shows a flowchart of heater control.

FIG. 5 shows temperature and heater control output when the present invention is used.

FIG. 6 is a diagram illustrating a cooling system.

FIG. 7 shows a conventional heater control.

FIG. 8 is a diagram illustrating cycle control.

[Explanation of symbols]

 1, 70 temperature sensor 2 overall operation rate calculation unit 3 operation rate reading unit 4, 24a time division table 5, 25, 76 cycle control unit 6, 71 heater 21, 75 temperature control unit 22 encoder 23 selector 24 memory 56 Refrigerator module 57 Compressor 59 Condenser 60 Evaporator 61 Heat exchanger 63 Cooling load 64 Tank 65 Flow rate sensor 66 Valve 67 Pump 68 Freezing prevention sensor 69 Heater controller 81 Cycle control circuit 82 Switch circuit 83 Transformer 84 Input terminal 85 AC power supply terminal 86 Heater connection terminal

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G05D 23/19 G05D 23/19 J // F28F 27/00 511 F28F 27/00 511K F-term (Reference) 5H004 GA05 GA15 GA34 GB20 HA01 HB01 HB05 JA01 JB01 KA32 KB02 KB04 KB06 KC02 5H323 AA05 BB02 BB03 BB12 CA04 CA09 CB02 CB23 CB35 EE01 KK07 LL01 LL02 LL17 MM02 MM15 QQ06 RR05

Claims (5)

[Claims] 1. A heater control method for controlling a cycle control unit for supplying electric power to a heater using a time division table storing a plurality of ordered sets of time division operation rates corresponding to the entire operation rate. Then, the overall utilization rate is calculated at regular time intervals, and using the overall utilization rate obtained as a result of the calculation, an ordered set of the time-division utilization rates stored in the time-division table is obtained. A heater control method, wherein time-division operating rates are sequentially read from an ordered set of operating rates for each time-division cycle, and the read operation-rate signal of the time-division cycle is passed to a cycle control unit. 2. The heater control method according to claim 1, wherein the heater adjusts a cooling water temperature of the electronic device cooling device. 3. A heater control device comprising: an overall operation rate calculation unit to which an output of a temperature sensor is input; a time division table; an operation rate reading unit; and a cycle control unit for supplying power to the heater. The time division table stores a plurality of ordered sets of the time division utilization rate corresponding to the overall utilization rate, and the overall utilization rate calculation unit calculates the overall utilization rate based on the output of the temperature sensor and the set value. The operating rate reading unit uses the overall operating rate calculated by the overall operating rate calculating unit at regular time intervals to calculate the operating rate of the time-sharing cycle from the ordered set of the time-sharing operating rates existing in the time-sharing table. A heater control device, wherein the heaters are sequentially taken out at every time division time and passed to a cycle control unit. 4. The heater control device according to claim 3, wherein the temperature sensor detects the temperature of the cooling water of the electronic device cooling device, and the heater adjusts the temperature of the cooling water. 5. A cooling device for an electronic device, comprising: a temperature sensor for detecting a temperature of cooling water; a heater for heating the cooling water; and a heater control device for controlling the heater based on an output of the temperature sensor and a set value. The heater control device includes an overall operation rate calculation unit, a time division table, an operation rate reading unit, and a cycle control unit that supplies power to the heater. A plurality of ordered sets of time-sharing operation rates corresponding to the above, the overall operation rate calculation unit calculates the entire operation rate based on the output of the temperature sensor and the set value, and the operation rate reading unit performs Using the total operation rate calculated by the total operation rate calculation unit for each time, the operation rates of the time division cycle are sequentially extracted for each time division time from the ordered set of the time division operation rates existing in the time division table, and the cycle is A cooling device for electronic equipment, which is transferred to a control unit.