JPH0627600B2 - Cooling output measuring device for water tank type cooler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a cooling output measuring device for a water tank type cooler used for a science test or the like.

<Prior Art> When measuring a cooling output of a water tank type cooler that cools a cooling medium such as water or an antifreezing liquid in a water tank, conventionally, a cooling target (cooling medium, water tank, pipe) is used as a cooling output, that is, a cooling heat amount. Etc.) actual temperature drop (cooling curve)
For example, when ignoring the heat capacity of the tank and others, the following equation Q (Kcal / H) = T (℃ / H) × V (l) × C _p (Kcal / ℃ ・ kg) × q (kg / l) Q: Cooling The heat of cooling, T: temperature gradient, V: volume of the object to be cooled, C _p : specific heat of the object to be cooled, q: specific gravity of the object to be cooled, were calculated by substituting the respective numerical values.

<Problems to be Solved by the Invention> However, when a refrigerator is used as a cooling source, its cooling output changes depending on the temperature of the specific cooling body. Further, as shown in FIG. When the temperature difference from the body gradually decreases as the temperature drops, the temperature gradient T changes with each temperature, so the temperature gradient T at the temperature to be measured had to be obtained successively by drawing a tangent line to the cooling curve. . Furthermore, since the pressure and temperature inside the pipe are constantly changing during cooling when the refrigerator is used, the actual cooling output of the cooler when the refrigerator is operating steadily at a certain temperature is tangential. There is a problem that the temperature gradient T obtained by the above does not match the value calculated by substituting it in the above calculation formula.

In addition, the measurement and management of each value of V, C _p , and q of the cooled object becomes complicated, and uncertain factors such as the delay of the reached temperature due to the difference in thermal conductivity between the cooled object and the water tank, piping, etc. However, there is a problem that it is very difficult to measure the correct cooling output (cooling heat quantity).

<Means for Solving the Problems> The present invention provides a means for measuring a cooling output of a water tank type cooler including a water tank and a refrigerator for cooling a medium to be cooled in the water tank in a steady operation. A continuous proportional control temperature controller having a temperature sensor in contact with the medium and a heating heater to adjust the medium to be cooled to a set temperature, and a voltage supplied to the heating heater of the continuous proportional control temperature controller. The effective value converter for converting the current value to the effective value, the calculator for calculating the heat quantity of the heating heater by measuring the value of the effective value converter, and the heat quantity value calculated by the calculator. The present invention is intended to solve the above-mentioned problems by providing a display section for replacing and displaying the cooling output.

<Operation> When the temperature of the medium to be cooled, which is cooled by the refrigerator operating normally, is controlled with high accuracy by the continuous proportional control temperature controller, the amount of heat supplied by the heater for heating is continuously constant. Based on the principle that the heat quantity of the heating heater and the cooling output of the cooler in this state are balanced, the measured heat quantity of the heating heater is replaced with the cooling output of the cooler and displayed on the display. I did it.

<Example> An example will be described below with reference to the drawings.

The water tank type cooler 1 comprises a refrigerator 2 and a water tank 4 for containing a medium 3 to be cooled such as water or antifreeze liquid. As shown in FIG. 1, the cooling pipe 2a of the refrigerator 2 is connected to the medium to be cooled in the water tank 4. In addition to the storage type that is in contact with 3, the refrigerator 2 and the water tank 4 may have any structure of a circulation type that is connected by a pipe line. In the figure, 5 is a stirrer for making the entire temperature of the cooled medium 3 uniform.

The cooling output measuring device 6 has a continuous proportional control temperature controller 9 in which a temperature sensor 7 and a heater 8 for heating are connected outside by a connecting wire 7a and 8a, respectively, and the temperature controller 9 is used for heating. The amount of heat of the heating heater 8 is calculated according to the effective value converters 10 and 11 that detect the voltage / current supplied to the heater 8 and convert it into the effective value, and the signal values sent from the converters 10 and 11. The calculator 12 configured as described above and the display unit 13 that digitizes and displays the numerical value calculated by the calculator 12 are displayed.

In the circuit configuration shown in FIG. 2, the continuous proportional control temperature controller 9 detects and amplifies the unbalanced voltage between the temperature sensor 7 and the temperature setting switch aa 'by the error amplifier 9a by the feedback effect of the temperature sensor 7. The temperature of the system in which the triac roll call circuit 9b that receives the amplified signal value continuously and variably supplies the energizing current to the heating heater 8 from 0% to ≈100% to control the temperature of the cooling medium 3 with high accuracy. It is a regulator that constantly heats the electric power required for temperature control, unlike the method of controlling temperature by repeatedly turning ON / OFF a constant power supply or the time proportional control method of supplying power in stages. The heater 8 is energized.

The temperature sensor 7 and the heating heater 8 of the cooling output measuring device 6 configured as described above are set in the water tank 4 of the cooler 1 in which the refrigerator 2 is in a steady state, and the cooling output measuring device 6 By setting the continuous proportional control temperature controller 9, the cooling medium 3 is controlled to a constant temperature.

The effective value converters 10 and 11 calculate the voltage and current supplied to the heating heater 8 to calculate the heat quantity of the heating heater 8, heater heat quantity (Kcal / H) = P (KW) × 860 (Kcal / H ・ KW) = Irms (A) × Erms (V) × 860 (Kcal / H ・ K
W) P: Heater power, I: Heater current, V: Heater voltage, 860 (Kcal / HKW): Heater heat equivalent (constant) The measurement is performed and the measured numerical value (heater heat amount) is digitized and displayed on the display unit 13.

When the temperature of the cooling medium 3 is controlled with high accuracy, the variation in the amount of heat applied from the heating heater 8 is small and almost constant, and the amount of heat of the heating heater 8 and the cooling output of the cooler 1 at this time are balanced. Based on the principle of
That is, the amount of heat of the heating heater 8 digitally displayed can be read by substituting it as a numerical value representing the cooling output of the cooler 1 at that temperature.

In addition to the digital display, the display unit 13 may be an analog display, and a recorder (chart) 14 may be arranged in parallel to hold a record.

Further, the measurement of the cooling output of the thermostatic device having the temperature control device including the heater for heating also stops the temperature control function or continuously supplies the electric power to the heater for heating to the device of the present invention. The measurement can be performed by a simple switching work that is performed by an adjuster.

<Effects of the Invention> As described above, the present invention is designed to measure the heat quantity of the heating heater of the continuous proportional control temperature controller and replace it with the cooling output of the balanced cooler for display. In addition to being automated, the effects of many uncertainties can be eliminated and the cooling output of the cooler can be measured quickly and accurately. Further, since the refrigerator is operated in a steady state, it is easy to compare and examine the data unique to the refrigerator and the data in the mounted state, and it is possible to rationalize the inspection and maintenance work of the cooler.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a measurement state of a cooling output by an apparatus of an embodiment of the present invention, FIG. 2A is a circuit diagram of a continuous proportional control temperature controller, and FIG. 2B is a diagram showing a current controlled by the controller. Waveform diagram, FIG. 3 is a graph diagram showing an example of tangent lines drawn to obtain the temperature gradient from the cooling curve measured by the conventional method, 1 is a cooler, 2 is a refrigerator, 3 is a medium to be cooled, 4 is a water tank 5 is a stirrer, 6 is a cooling output measuring device, 7 is a temperature sensor, 8 is a heater for heating, 9 is a continuous proportional control temperature controller, 10 is a voltage effective value converter, and 11 is a current effective value converter. , 12 is a computing unit,
13 is a digital display, and 14 is a recorder.

Claims (1)

[Claims] 1. As a means for measuring the cooling output of a water-tank type cooler comprising a water tank and a refrigerator for cooling the medium to be cooled in the water tank in a steady operation, a temperature sensor in contact with the medium to be cooled is added. A continuous proportional control temperature controller having a temperature heater for adjusting the medium to be cooled to a set temperature, and a voltage / current value supplied to the heating heater of the continuous proportional control temperature controller to an effective value. An RMS value converter for conversion, an arithmetic unit for measuring the numerical value of the RMS value converter to calculate the heat quantity of the heating heater, and a display for replacing the numerical value of the heat quantity calculated by the arithmetic unit with the cooling output. And a cooling output measuring device for a water tank type cooler.