JP2004206518A - Thermoregulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoregulator for heating a sample by warm water, and exactly maintaining predetermined temperature and prescribed water volume. <P>SOLUTION: The thermoregulator is provided with a tank 2 in which water 3 is stored, pipes 18, 26, a circulation pump 21 for circulating the water 3, a heater 23 for heating the water in the pipes 18, 26 and a cooling pump 25 for supplying cooled water 14 in the tank 2 and maintains the water in the tank 2 to the predetermined temperature by separately using a warming mode by the heater 23 and a cooling mode by the cooled water 14. In addition, it is desirable that the cooling pump 25 supplies the cooling water 14 in the tank 2 by predetermined volume after a thermal insulation mode by which the water 3 in the tank 2 is maintained at the predetermined temperature. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a thermostat.
[0002]
[Prior art]
Conventionally, a thermostat has a housing and an openable / closable door. By closing the door, outside air can be prevented from entering the inside of the housing. The sample in the housing is heated by the gas in the housing (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-11-89561
[Problems to be solved by the invention]
Many studies have been made at various research institutions on changes in cells caused by gently heating a living body. In order to perform cultivation and evaluation of these living bodies and cells by the thermal effect, it is not desirable to heat the sample with a gas.
[0005]
However, when heating with hot water, there is a second disadvantage that it is difficult to maintain the hot water within a predetermined temperature (for example, within a predetermined temperature ± 0.1 ° C.). Furthermore, in the case of heating with hot water, there is a second disadvantage that the hot water evaporates and the amount of hot water decreases from a predetermined amount in a state where the hot water state is maintained. Therefore, the present invention provides a constant temperature apparatus that can heat a sample with hot water, accurately maintain a predetermined temperature, and maintain a predetermined water amount, in consideration of such conventional disadvantages.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, in the present invention of claim 1, a water tank in which water is stored, a pipe and a circulation pump for circulating the water, a heater for heating water in the pipe, and cooling in the water tank A cooling pump for supplying water is provided, and the water in the water tank is maintained at a predetermined temperature by separately using a heating mode by the heater and a cooling mode by the cooling water.
[0007]
According to the second aspect of the present invention, the cooling pump supplies the cooling water by a predetermined amount into the water tank after the heat retention mode in which the water in the water tank is maintained at a predetermined temperature.
[0008]
According to the third aspect of the present invention, the rotation speed of the cooling pump after the heat retention mode is set to be smaller than the rotation speed of the cooling pump before the heat retention mode.
[0009]
According to a fourth aspect of the present invention, a control unit is provided, and the control unit controls the cooling pump to operate intermittently after the heat retention mode so as to shorten the operation time and increase the stop time.
[0010]
According to a fifth aspect of the present invention, a computer connected to the control unit is provided, and the computer gives the control unit a fixed operation time and the stop time according to environmental conditions.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a constant temperature apparatus 1 according to an embodiment of the present invention will be described with reference to the schematic configuration diagram of FIG. In FIG. 1, the water tank 2 is formed in a substantially concave shape whose upper part is open. Water 3 is stored in the water tank 2. The shelf 4 is fixed on the upper part of the water tank 2, and the container 5 containing the sample is arranged on the shelf 4.
[0012]
The housing 6 is provided so as to surround the water tank 2. An outlet 7, a drain 8, and an inlet 9 are provided so as to penetrate the housing 6 and the water tank 2.
[0013]
One side of the drain section 8 is connected to a drain pipe 10, and the other side is connected to a drain valve 11. The handle 12 provided on the drain valve 11 is configured such that the water level of the overflow is adjusted by being turned by the user.
[0014]
The cooling tank 13 is formed in a substantially concave shape whose upper part is open, and cooling water 14 is stored in the cooling tank 13. The door 15 is provided on a side surface of the cooling tank 13 and is configured to be openable and closable, so that a user can supply the cooling water 14.
[0015]
The water level gauge 16 is for measuring the water level of the cooling water 14. One side of the inlet 17 is connected to the outlet 7 through a pipe 18. A thermometer 19 is provided at an appropriate position of the entrance tool 17. A flow switch 20 is provided at an appropriate position of the inlet device 17.
[0016]
The other side of the inlet 17 is connected to the suction side of the circulation pump 21. The discharge side of the circulation pump 21 is connected to one side of the outlet 22.
[0017]
A heater 23 is provided at an appropriate position of the outlet 22. A switching valve 24 is provided at an appropriate position of the outlet 22, and the switching valve 24 is provided on the discharge side of the cooling pump 25. The suction side of the cooling pump 25 is configured to suck the cooling water 14 in the cooling tank 13. The other side of the outlet 22 is connected to the inlet 9 via a pipe 26.
[0018]
With the above configuration, when the switching valve 24 is closed, the water 3 in the water tank 2 passes through the outlet 7, the pipe 18, the inlet 17, and the circulation pump 21, and is heated by the heater 23. , Through the outlet 22, the pipe 26, and the inlet 9 and back into the water tank 2.
[0019]
Thus, the pipes 18 and 26 for circulating the water 3 in the water tank 2, the circulation pump 21, and the heater 23 for heating the water in the pipes 18 and 26 are provided. When the switching valve 24 is opened, the water 3 passes through the outlet 7, the pipe 18, the inlet 17, and the circulation pipe 21 and passes through the switching valve 24. At this time, the cooling water 14 in the cooling tank 13 passes through the suction side of the cooling pump 25, passes through the discharge side, and enters the switching valve 24.
[0020]
In this manner, the water 3 in the water tank 2 and the cooling water 14 in the cooling tank 13 are mixed by the switching valve 24, and the mixed water is mixed with the other side of the outlet 22, the pipe 26, and the inlet 9. And return to the water tank 2. Thus, the cooling pump 25 that supplies the cooling water 14 into the water tank 2 is provided.
[0021]
A circuit board 27 is provided above the cooling tank 13. The control unit 28 includes, for example, a CPU and is disposed on the circuit board 27. The control unit 28 is connected to the male connector 29, the heater 3, the thermometer 19, the circulation pump 21, the cooling pump 25, the hot water temperature regulator 30, the voltage regulator 31, the switching valve 24, and the like. I have. The constant temperature device 1 is configured by the above components.
[0022]
The computer 32 is, for example, a personal computer and has an input unit 33 and the like. One side of the cable 34 has a female connector 35, and the other side is connected to the computer 32. The female connector 35 and the male connector 29 are configured to be mechanically and electrically connected.
[0023]
Next, the operation of the constant temperature apparatus 1 will be described with reference to FIGS. FIG. 2 is a flowchart showing the main operation of the thermostat 1, and FIG. 3 is a flowchart following FIG.
[0024]
In these figures, the control unit 28 determines whether or not there is an input signal from the computer 32 (see S1 in FIG. 2). If there is no input signal, the control unit 28 continues the standby state.
[0025]
If the input signal is present, the control unit 28 determines whether the current temperature of the water 3 in the water tank 2 is equal to or higher than a set temperature (for example, 42 ° C.) (see S2 in FIG. 2).
[0026]
If the current temperature of the water 3 (for example, 46 ° C.) is equal to or higher than the set temperature, the control unit 28 affirms the determination in S2 and sets the cooling mode (see S3 in FIG. 2). The cooling mode is a mode in which the circulation pump 21 is operated, the heater 23 is stopped, the switching valve 24 is opened, and the cooling pump 25 is fully operated (operated at 100% output).
[0027]
Next, the control unit 28 determines whether or not the current temperature of the water 3 is equal to or lower than a set temperature (42 ° C.) + Hysteresis (2) (for example, 3 ° C.) (see S4 in FIG. 2). In the above example, since the current temperature of the water 3 is 46 ° C., the control unit 28 denies the determination in S4.
[0028]
In this way, the control unit 28 repeats S3 and S4. At this time, the control unit 28 applies a relatively large voltage to the cooling pump 25 via the voltage regulator 31 in the cooling mode before the heat retaining mode (described later).
[0029]
As a result, the rotation speed of the cooling pump 25 is as large as 3000 rpm, for example, and the cooling water 14 is discharged at a flow rate of 7 liter / minute. At this time, since the switching valve 24 is open, the water 3 (about 46 ° C.) discharged from the circulation pump 21 and the cooling water (about 10 ° C.) discharged from the cooling pump 25 are mixed in the outlet 22. This mixed water is supplied into the water tank 2 through the pipe 26.
[0030]
Further, the mixed water in the water tank 2 is sucked by the circulation pump 21 through the pipe 18 and is discharged again into the outlet 22. In this way, the temperature of the water 3 in the water tank 2 drops rapidly.
[0031]
In this way, when the temperature of the water 3 drops to 45 ° C., the control unit 28 affirms the determination in S4 and sets the natural cooling mode (see S5 in FIG. 2). The natural cooling mode is a mode in which the circulation pump 21 is operated, the heater 23 is stopped, the switching valve 24 is closed, and the cooling pump 25 is stopped.
[0032]
Next, the controller 28 determines whether or not the current temperature of the water 3 is equal to or higher than the set temperature (42 ° C.) + Hysteresis (3) (for example, 0.1 ° C.) (see S6 in FIG. 2). In the above example, since the temperature of the water 3 is still high, the control unit 28 denies the determination in S6 and repeats S5 and S6.
[0033]
Thus, the water 3 (45 ° C.) and the cooling water 14 (10 ° C.) are mixed, and the mixed water is circulated by the pump 21. As a result, it is assumed that the temperature of the water 3 gradually decreases to, for example, 42.1 ° C.
[0034]
At this time, the control unit 28 repeats S6 to set the temperature raising mode (see S7 in FIG. 2). The temperature raising mode is a mode in which the circulation pump 21 is operated, the heater 23 is operated in full operation (operation at 100% output), the switching valve 24 is closed, and the cooling pump 25 is stopped.
[0035]
Next, the control unit 28 determines whether or not the current temperature of the water 3 is equal to or higher than the set temperature (42 ° C.) − Hysteresis (3) (0.1 ° C.) (see S8 in FIG. 2). In the above example, since the current temperature of the water 3 is lower than 41.9 ° C. (since the water temperature drops), the control unit 28 denies the determination of S8 and repeats the operations of S7 and S8.
[0036]
When the above operation is repeated (that is, the temperature increase mode is executed), the current temperature of the water 3 returns to 41.9 ° C., the control unit 28 affirms S8, and the heat retention mode (that is, the steady operation mode, (See S9 in FIG. 3).
[0037]
Also, unlike the above description, when the current temperature of the water 3 is lower than the set temperature (42 ° C.), the control unit 28 denies S2 and sets the temperature increase mode (see S10 in FIG. 2).
[0038]
Next, the control unit 28 determines whether or not the current temperature of the water 3 is equal to or higher than the set temperature (42 ° C.) − Hysteresis (3) (0.1 ° C.) (see S11 in FIG. 2). If the current temperature is lower than the above temperature, the control unit 28 repeats the operations of S10 and S11.
[0039]
If the current temperature has returned to the above-mentioned temperature, the control unit 28 affirms S11 and sets the heat retention mode (see S9 in FIG. 3).
[0040]
The warming mode is a mode in which the circulation pump 21 is operated, the heater 23 is operated at 20% to 30% of the total output, the switching valve 24 is closed, and the cooling pump 25 is stopped. Thus, in the heat retention mode, the current temperature of the water 3 in the water tank 2 is maintained within the set temperature (eg, 42 ° C.) ± 0.1 ° C.
[0041]
The features of the above operation are summarized. By separately using the heating mode by the heater 23 (see S7) and the cooling mode by the cooling water 14 (see S3), the water 3 in the water tank 2 can be maintained at a predetermined temperature (see S9). .
[0042]
Next, the control unit 28 determines whether or not the difference (temperature deviation) between the current temperature of the water 3 and the predetermined temperature is equal to or greater than hysteresis (1) (for example, an error due to disturbance, ± 0.5 ° C.). Is determined (see S12 in FIG. 3).
[0043]
If the temperature deviation is equal to or greater than the hysteresis (1), the control unit 28 affirms the determination in S12 and returns to the position immediately before S2 in FIG. If the temperature deviation is small, the control unit 28 denies the determination in S12.
[0044]
Next, the control unit 28 determines whether the set temperature has been changed (see S13 in FIG. 3). If the user has changed the set temperature, the control unit 28 affirms the determination in S13 and returns to immediately before S2 in FIG. If the user has not changed, the control unit 28 denies the determination in S13.
[0045]
Then, the control unit 28 determines whether or not the mode is the water supply mode (see S14 in FIG. 3). If the user has not pressed the water supply mode selection key (not shown) provided on the thermostat 1, the control unit 28 denies the determination in S14 and returns to immediately before S9.
[0046]
In the above example, it is assumed that the user has pressed the key. As a result, the control unit 28 affirms the determination in S14. Next, the control unit 28 determines whether or not the supply interval has elapsed (see S15 in FIG. 3). That is, the control unit 28 determines whether or not the time from the start of the heat retention mode (see S9) to the start of the next water supply mode (described later) is equal to or longer than the supply interval time.
[0047]
In the above example, since the heat retention mode has just started, the control unit 28 denies the determination of S15 and repeats the operations of steps S9, S12, S13, S14, and S15. When time elapses due to the repetition of the above operation, the control unit 28 affirms S15.
[0048]
Next, the control unit 28 sets the water supply mode (see S16 in FIG. 3). The water replenishment mode is a mode in which the circulation pump 21 is operated, the heater 23 is operated at 20% to 30% of the total output, the cooling pump 25 is operated at about 10% of the total output, and the switching valve 24 is opened. is there.
[0049]
In the water supply mode, the control unit 28 causes the cooling pump 25 to apply a relatively small voltage via the voltage regulator 31. As a result, the rotation speed of the cooling pump 25 is as small as 300 rpm, for example, and the cooling water 14 is discharged at a flow rate of 0.7 liter / minute.
[0050]
Thus, the rotation speed (for example, 300 rpm) of the cooling pump 25 after the heat retention mode (see S9) is smaller than the rotation speed (for example, 3000 rpm) of the cooling pump 25 before the heat retention mode (see S9). It is set to be.
[0051]
In the water supply mode (see S16), the control unit 28 causes the cooling pump 25 to operate intermittently. For example, the operation time in one cycle is about 5 seconds, and the stop time in one cycle is about 20 minutes. Then, the control unit 28 operates the cooling pump 25 for only three cycles. That is, the total operation time is (5 seconds + 20 minutes) × 3 = 1 hour 15 seconds. The stop time (for example, 20 minutes) is the same as the replenishment interval time shown in S15.
[0052]
For example, the size of the water tank 2 is 430 mm in length, 360 mm in width, 240 mm in height, the temperature of the water 3 is 42 ° C., the temperature of the cooling water 14 is 10 ° C., and the cooling pump 25 is Operate intermittently.
[0053]
At this time, the supply amount of the cooling water 14 in the three cycles of the cooling pump 25 is 174 CC, and a decrease in the water level due to evaporation of the water 3 can be suppressed to within 1 mm. Further, by adding 58 CC per cycle of the cooling water 14 of 10 ° C. to the water 3 of 42 ° C., the temperature change of the water 3 in the water tank 2 can be kept within ± 0.1 ° C.
[0054]
As described above, when a predetermined time (for example, 1 hour and 15 seconds) elapses in the water supply mode (S16), the control unit 28 affirms the determination of “whether the predetermined time has elapsed” (see S17 in FIG. 3), and proceeds to S9. Return to just before. If the predetermined time has not elapsed, the control unit 28 repeats the operations of S16 and S17.
[0055]
The features of the water supply mode (see S16 in FIG. 3) will be summarized. After the heat retaining mode (see S9) in which the water 3 in the water tank 2 is maintained at a predetermined temperature (for example, 42 ° C.), the cooling pump 25 supplies the cooling water 14 into the water tank 2 by a predetermined amount (for example, 174 CC). I do.
[0056]
Further, after the heat retention mode (see S9), the control unit 28 controls the cooling pump 25 to operate intermittently to shorten the operation time (for example, 5 seconds) and lengthen the stop time (for example, 20 minutes). I do.
[0057]
It is assumed that the user inputs environmental conditions (for example, the set temperature of the water 3, the temperature of the air in the atmosphere, the humidity, the degree of opening of the water tank 2, etc.) to the input unit 33 provided in the computer 32.
[0058]
At this time, control means (comprising a CPU or the like, not shown) provided in the computer 32 instructs the control unit 28 to keep the operation time of the cooling pump 25 constant in the water supply mode (see S16) (for example, , 5 seconds) to provide an optimal stop time according to the above environmental conditions.
[0059]
That is, the computer 32 changes the water level of the water 3 in the water tank 2 so that the temperature of the water 3 in the water tank 2 is, for example, within ± 0.1 ° C. of the set temperature, and the water is replenished. For example, the stop time is calculated so as to be within 1 mm, and the control unit 28 is given the stop time.
[0060]
【The invention's effect】
In the present invention of claim 1, a water tank in which water is stored, a pipe and a circulation pump for circulating the water, a heater for heating the water in the pipe, and a cooling pump for supplying cooling water to the water tank are provided. The water in the water tank is maintained at a predetermined temperature by separately using a temperature increasing mode by the heater and a cooling mode by the cooling water. As described above, by separately using the temperature increasing mode and the cooling mode using the cooling water, the water temperature in the water tank can be maintained (attained) at a predetermined temperature more accurately and quickly.
[0061]
According to the second aspect of the present invention, the cooling pump supplies a predetermined amount of the cooling water into the water tank after the heat retention mode in which the water in the water tank is maintained at a predetermined temperature. According to the above configuration, by maintaining the supplied cooling water at a predetermined amount, the change in the water level in the water tank can be kept as small as possible.
[0062]
According to the third aspect of the present invention, the rotation speed of the cooling pump after the heat retention mode is set to be lower than the rotation speed of the cooling pump before the heat retention mode. As described above, by reducing the rotation speed of the cooling pump in the water supply mode, the discharge flow rate to the water tank can be reduced, and the change in the water level in the water tank can be reduced.
[0063]
According to a fourth aspect of the present invention, a control unit is provided, and the control unit controls the cooling pump to perform an intermittent operation after the heat retention mode so as to shorten the operation time and increase the stop time. As described above, by intermittently operating the cooling pump, the discharge amount of the cooling water to the water tank can be reduced, and a change in the water temperature in the water tank can be suppressed.
[0064]
According to a fifth aspect of the present invention, a computer connected to the control unit is provided, and the computer gives the control unit a constant operation time and the stop time according to environmental conditions. With the above configuration, even if the environmental conditions change, the computer can obtain the condition (the cooling pump stop time) in which the water temperature change in the water tank is small and the water level change in the water tank is small.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a thermostat 1 according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a main operation of the device 1.
FIG. 3 is a flowchart following FIG. 2;
[Explanation of symbols]
2 Water tank 3 Water 14 Cooling water 18, 26 Pipe 23 Heater 25 Cooling pump 28 Control unit

Claims (5)

A water tank in which water is stored, a pipe and a circulation pump for circulating the water, a heater for heating water in the pipe, and a cooling pump for supplying cooling water to the water tank; And a cooling mode using the cooling water, whereby the water in the water tank is maintained at a predetermined temperature. 2. The constant temperature apparatus according to claim 1, wherein the cooling pump supplies a predetermined amount of the cooling water into the water tank after a heat retention mode in which water in the water tank is maintained at a predetermined temperature. 3. 3. The constant temperature apparatus according to claim 2, wherein a rotation speed of the cooling pump after the heat retention mode is set to be lower than a rotation speed of the cooling pump before the heat retention mode. 4. 4. The constant temperature apparatus according to claim 3, wherein a control unit is provided, and the control unit controls the cooling pump to perform an intermittent operation after the heat retention mode so as to shorten an operation time and increase a stop time. 5. 5. The constant temperature apparatus according to claim 4, further comprising a computer connected to the control unit, wherein the computer provides the control unit with the constant operation time and the stop time according to environmental conditions.

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