JPH07121248A - Method and device for holding fluid at constant temperature - Google Patents

Abstract

PURPOSE:To provide the method and device which hold the fluid at constant temperature with high precision by smoothing temperature variation of the fluid. CONSTITUTION:An entrance-side mean temperature signal of the fluid, flowing through a 1st heat exchanger 15, which is calculated by a 1st temperature sensor 23 and an exit-side fluid temperature signal of the heat exchanger which is detected by a 2nd temperature sensor 24 are inputted to a temperature controller 21 and a control circuit which is driven by the temperature controller 21 performs PID control over the fluid temperature signals to control the electric feeding quantity and electric feeding direction of thermomodules 17, which heat and cool heat exchangers; and the thermomodules are repeatedly heated and cooled to make the temperature variation of the fluid smooth, thereby obtaining the fluid which is constant temperature with high precision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant temperature method and apparatus for using a fluid whose temperature fluctuates as a constant temperature fluid.

[0002]

2. Description of the Related Art Conventionally, as a fluid constant temperature device for keeping a fluid whose temperature fluctuates constant, one shown in FIG. 6 is known. The thermostatic device heats the fluid cooled by the chiller 1 by an electric heater 3 in a heating tank 2 in which the fluid flows, and detects the temperature of the fluid heated by the electric heater 3 by a temperature sensor 4, The temperature controller 5 controlled by the output signal of the sensor 4 controls the amount of electricity supplied to the electric heater 3 to make the fluid constant temperature, and the constant temperature fluid is supplied to the constant temperature fluid object 6. Reference numeral 7 in the figure is a thyristor.

In the above known constant temperature device, since the temperature of the fluid controlled by the chiller 1 varies greatly, the electric heater 3 controlled by the temperature sensor 4 controls the fluid once cooled.
However, since the electric heater 3 can only adjust the temperature within a range of about ± 0.2 ° C., it cannot be a highly accurate constant temperature fluid.

[0004]

The problem to be solved by the present invention is to smooth the temperature fluctuation of the fluid,
It is an object of the present invention to provide a constant temperature method for a fluid and a device for the constant temperature of the fluid with high precision.

[0005]

In order to solve the above-mentioned problems, a method for isolating a fluid according to the present invention is a method for isolating a fluid in which a temperature variation of the fluid is smoothed in a heat exchanger to obtain a fluid of a constant temperature. The heat exchanger is cooled and heated by a thermo-module, and the energization amount and the energizing direction of the thermo-module are set as a temperature setting signal with the average temperature of the fluid on the inlet side of the heat exchanger as a fluid on the outlet side of the heat exchanger. The feature is that the temperature variation of the fluid is smoothed by PID control of the temperature. Further, in order to solve the same problem, in the constant temperature method of the fluid, the energization amount and energization direction of the thermo module, the temperature signal input from an external computer as a temperature setting signal, the fluid of the outlet side fluid of the heat exchanger The feature is that the temperature variation of the fluid is smoothed by PID control of the temperature.

Further, in order to solve the same problem, a fluid thermostatic apparatus according to the present invention is a fluid thermostatic apparatus which smoothes a temperature variation of a fluid in a heat exchanger to obtain a fluid of a constant temperature. , A heat exchanger through which the fluid flows,
A thermo module for heating and cooling the heat exchanger, a first temperature sensor for measuring and outputting an average temperature signal by measuring the temperature variation of the fluid on the inlet side of the heat exchanger, and a fluid on the outlet side of the heat exchanger. A heat exchange device having a second temperature sensor for detecting the temperature of the fluid and outputting a fluid temperature signal; a temperature controller to which the signals of the first and second temperature sensors are inputted; A control circuit for controlling the energization amount and the energization direction of the thermo module to smooth the temperature fluctuation of the fluid by PID controlling the fluid temperature signal using the temperature signal as a temperature setting signal. I am trying. In order to solve the same problem, the constant temperature device for the fluid detects the temperature of the heat exchanger through which the fluid flows, a thermo module for heating and cooling the heat exchanger, and the outlet side fluid of the heat exchanger. A heat exchange device having a temperature sensor for outputting a fluid temperature signal, an external computer for outputting a temperature signal, a temperature controller to which the temperature signal and the fluid temperature signal are input, and the external controller driven by the temperature controller. And a control circuit for smoothing the temperature fluctuation of the fluid by controlling the energization amount and the energization direction of the thermo module by PID controlling the fluid temperature signal using the temperature signal of the computer as a temperature setting signal. Is characterized by.

[0007]

The control circuit driven by the temperature controller uses the average temperature signal on the inlet side of the fluid flowing through the heat exchanger as the temperature set value and sets the temperature signal on the outlet side of the fluid to PI.
D control, thereby controlling the energization amount and energization direction of the thermo module for heating and cooling the heat exchanger, thereby adjusting the heating amount and cooling amount of the thermo module for heating and cooling the heat exchanger, and heating. And the switching of the cooling smoothes the temperature fluctuation of the fluid. Therefore, the fluid whose temperature fluctuates can be made constant temperature with high accuracy. Further, since the temperature fluctuation of the fluid is smoothed by performing the same control by the control circuit using the temperature signal input from the external computer as the temperature set value, it is possible to make the temperature of the fluid whose temperature also fluctuates constant. .

The switching between heating and cooling by the thermomodule can be instantaneously performed by switching the energizing direction of the thermomodule, so that the temperature can be smoothed quickly. Further, since the heating and cooling of the fluid is to smooth the temperature of the fluid to a constant temperature and not to further heat or cool the fluid to a constant temperature, it may be the case where the flow rate of the fluid is large. However, the thermo module having a small heating and cooling capability can keep the fluid at a constant temperature.

[0009]

1 and 2 show a first embodiment of the present invention,
This fluid constant temperature device includes a fluid supply channel 11 and a reflux channel 12 of the fluid, a first heat exchanger 15 in the supply channel stream 11 and a second heat exchanger in the reflux channel 12. 16 and a heat exchanging device 14 having a thermo module 17 composed of a Peltier element between the heat exchangers 15 and 16 ..., One of the supply passage 11 and the return passage 12 cools or heats the fluid. The cooling / heating device 18 is connected to the other, and the other is connected to a constant temperature fluid object 19 to which a constant temperature fluid is supplied. The above fluids such as cooling water and cutting oil are
The heating device 18 cools or heats the temperature to a substantially constant temperature on average, but the temperature fluctuates with time.

The heat exchanging device 14 measures the temperature of the temperature controller 21, the control circuit 22 described later driven by the temperature controller 21, and the temperature of the fluid on the inlet side of the first heat exchanger 15 for a desired time (3 to 3). Calculate the average temperature of 10 minutes),
First temperature sensor 23 that outputs this as an average temperature signal
And a second temperature sensor 24 that detects the temperature of the fluid on the outlet side of the first heat exchanger 15 and outputs a fluid temperature signal. The average temperature signal calculated by the first temperature sensor 23 and the fluid temperature signal detected by the second temperature sensor are input to the temperature controller 21, and the control circuit 22 uses the average temperature signal as a temperature set value for the fluid. Temperature signal is P
The ID module is configured to smooth the temperature fluctuation of the fluid by controlling the energization amount and the energization direction of the thermo module 17 ...

In the first embodiment described above, when the fluid whose temperature has fluctuated, which is cooled or heated in the cooling / heating device 18, is supplied to the first heat exchanger 15, the first temperature sensor 23 causes the first heat exchanger 15 to operate. The temperature fluctuation of the inlet side fluid is measured, the average temperature is calculated, the second temperature sensor 24 detects the fluid temperature of the outlet side fluid, and these signals are input to the temperature controller 21. The control circuit 22 driven by the temperature controller PID-controls the fluid temperature signal using the average temperature signal as a temperature set value, and thereby controls the energization amount and the energization direction of the thermo module 17 ,. Since the temperature of the fluid passing through the first heat exchanger 15 is smoothed by repeating cooling and heating by 17, ... (Refer to FIG. 3), the fluid is made into a highly accurate constant temperature with a temperature fluctuation of about ± 0.01 ° C. can do.

Unlike the known thermostatic device, the thermostatic device of the first embodiment does not further cool or heat the fluid, which is kept at a substantially constant temperature by the cooling / heating device 18, to make it a constant temperature fluid. Since the temperature is smoothed by repeating the cooling and heating of the fluid by the thermo module 17, ..., The heating and cooling capacity may be small. Can be controlled. Further, the thermo module can instantaneously switch between heating and cooling of the first heat exchanger by switching the energization direction,
The temperature fluctuations are smoothed quickly.

The fluid whose temperature has risen or dropped in the constant temperature fluid object 19 is the second heat exchanger 1 in the return flow passage 12.
6 through the thermo-module 1 in the heat exchanger 16.
The heat of 7, ... Is cooled and heated and is returned to the cooling / heating device 18. In the first embodiment, by providing the second heat exchanger 16 in the reflux flow passage 12, the flow passage structure between the cooling / heating device 18 and the constant temperature fluid object 19 can be simplified. it can. Further, since the reflux fluid flowing through the second heat exchanger 16 can cool and heat the thermo modules 17, ..., The efficiency thereof is improved.

FIGS. 4 and 5 show a second embodiment of the present invention. The constant temperature device of the second embodiment outputs an intended temperature signal to the cooling / heating device 18 and the temperature controller 21 by an external computer 26. And a temperature sensor 2 that detects the temperature of the fluid on the outlet side of the first heat exchanger 15 and outputs a fluid temperature signal.
7 and 7. Since the other structure of the second embodiment is the same as that of the first embodiment, the same reference numerals are given to the main parts of the drawing, and the detailed description will be omitted. In the second embodiment, the cooling / heating device 1 is controlled by the temperature signal from the external computer 26.
8, the temperature of the fluid is controlled, and the control circuit 22 performs PID control of the fluid temperature signal of the temperature sensor 27 by using the above signal of the external computer 26 as a temperature set value. And controlling the energizing direction. Since the other operations of the second embodiment are the same as those of the first embodiment, the description thereof will be omitted.

In each of these embodiments, the second heat exchanger 16 is provided in the reflux flow passage 12, but the present invention is not limited to this, and the constant temperature fluid object 19 and the cooling object are cooled. The heating device 18 may be directly connected by the reflux flow passage without passing through the heat exchanger, and the second heat exchanger 16 may be cooled and heated by a separate means (not shown).

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment.

FIG. 2 is a block diagram of the same.

FIG. 3 is a diagram showing smoothing of temperature.

FIG. 4 is a configuration diagram of a second embodiment.

FIG. 5 is a block diagram of the same.

FIG. 6 is a configuration diagram of a known constant temperature fluid supply device.

[Explanation of symbols]

 14 Heat Exchanger 15 First Heat Exchanger 17 Thermo Module 21 Temperature Controller 22 Control Circuit 23 First Temperature Sensor 24 Second Temperature Sensor 26 External Computer 27 Temperature Sensor

Claims (4)

[Claims] 1. A method of constant temperature of a fluid, wherein temperature fluctuations of the fluid are smoothed in a heat exchanger to obtain a constant temperature fluid, wherein the heat exchanger is cooled and heated by a thermo module, and the energization amount of the thermo module is changed. The temperature variation of the fluid is smoothed by PID controlling the fluid temperature at the outlet side of the heat exchanger with the average temperature of the fluid at the inlet side of the heat exchanger as a temperature setting signal. Method of constant temperature of fluid. 2. The fluid temperature of the outlet side fluid of the heat exchanger is set to PI with the energization amount and energization direction of the thermo module as a temperature setting signal input from an external computer
The temperature control method for a fluid according to claim 1, wherein the temperature variation of the fluid is smoothed by performing D control. 3. A fluid constant temperature device for smoothing temperature fluctuations of a fluid in a heat exchanger to obtain a constant temperature fluid, wherein the constant temperature device heats and cools the heat exchanger through which the fluid flows. Thermo module, first temperature sensor for measuring temperature variation of fluid on inlet side of heat exchanger and calculating and outputting average temperature signal, and fluid temperature signal for detecting temperature of fluid on outlet side of heat exchanger A heat exchanging device having a second temperature sensor for outputting the temperature, a temperature controller to which signals of the first and second temperature sensors are input, and a temperature controller driven by the temperature controller to use the average temperature signal as a temperature setting signal for the fluid. A control circuit for controlling the energization amount and the energization direction of the thermo module by PID control of the temperature signal to smooth the temperature fluctuation of the fluid. Fluid thermostat. 4. A thermostat for detecting the temperature of a heat exchanger through which a fluid flows, a thermomodule for heating and cooling the heat exchanger, and a temperature at which the fluid on the outlet side of the heat exchanger outputs a fluid temperature signal. A heat exchange device having a sensor, an external computer that outputs a temperature signal, a temperature controller to which the temperature signal and the fluid temperature signal are input, and a temperature controller that is driven by the temperature controller to change the temperature signal of the external computer to a temperature setting signal. 5. A control circuit for smoothing the temperature fluctuation of the fluid by controlling the energization amount and the energization direction of the thermo module by PID-controlling the fluid temperature signal as described above. A constant temperature device for fluid as described in.