JPS6317966Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a water cooler.

As shown in the system diagram in Fig. 1, the known air-cooled chilling unit includes a compressor 1, a condenser 2, a blower 3, a pressure reducing valve 4, an evaporator 5, an accumulator 8, a temperature detector 6 for anti-freezing, and its sensor. It consists of a hot section 6a', water side valves 20, 21, etc., the refrigerant flows as shown by the solid line arrow, and the water flows as shown by the dotted line arrow, respectively.
In order to prevent punctures due to freezing of water caused by forgetting to open the tubes 0 and 21, the temperature of the refrigerant on the tube wall of the evaporator 5 is detected by the antifreeze temperature sensing section 6a'.

In recent years, this type of chilling unit has been operated for cooling even in the winter, when the outside temperature is 15
℃ or below, even if water is flowing normally to the water side of the evaporator 5 at the time of startup after a stop period of more than one day and night, as shown in the temperature diagram in FIG. falls below the cut-off temperature _T0 of the antifreeze temperature detector 6 within 10 seconds after starting, and the protective device is activated to cause an abnormal stop.

If the set value T ₀ of the antifreeze temperature detector 6 is lowered in order to avoid such an abnormal stop, it will become impossible to prevent the evaporator 5 from freezing, and the
Even if the antifreeze temperature sensor 6 is short-circuited for 10 seconds, the tube wall temperature remains at the cut-in temperature of the antifreeze temperature sensor 6.
There are cases where the voltage does not rise to T ₁ , so in such a case, the abnormal stop will continue even after the short circuit is removed.

This invention was proposed in view of these circumstances, and aims to provide a reliable water cooler that can be started and operated even at low outside temperatures. and a water cooler comprising an evaporator comprising an inner pipe through which a refrigerant flows and an outer pipe through which water flows, a temperature detector having a temperature sensing section attached to an outlet refrigerant piping section of the evaporator;
A temperature sensor is attached to the inlet outer pipe section through which the water of the evaporator flows, and when the detected temperature of each of the temperature detectors is below a preset cut-off value, the temperature sensor is connected to the refrigerant compressor motor. It is characterized by comprising a means for cutting off the energization.

An embodiment of the present invention will be explained with reference to the drawings.
Figure 3 is its system diagram, Figure 4 is a partially enlarged view of the evaporator in Figure 3, Figure 5 is a sectional view taken along - in Figure 4, and Figure 6 is the refrigerant inlet portion of Figure 4. 7 and 8 are sectional views taken along the - and - lines of FIG. 6, respectively. FIG. 9 is a circuit diagram showing the control system of FIG. 3, and FIGS. 10 and 11. are graphs showing the detected temperature of the temperature sensing part 7a in Fig. 3. Fig. 10 shows the graph when the outside air temperature is 15°C or more, and Fig. 11 shows the graph when the outside air temperature is 15°C or less or when the refrigerant flow rate is normal. Fig. 12 is a diagram showing the detected temperature of the temperature sensor 6a in Fig. 3 when the outside temperature is below 15°C or when the refrigerant amount is below 60% of the normal amount. Indicate the case.

First, in FIGS. 3 to 8, the same reference numerals as in FIG. 1 indicate the same members as in FIG. Detector 7 is a temperature sensor for anti-freezing having a temperature sensing part 7a attached to the refrigerant outlet pipe 11 of the evaporator 5; 10 is a refrigerant inlet pipe; 11 is a refrigerant outlet pipe; 501 is a water inlet; 502 is a Water outlet section, 5
03 is a refrigerant inlet distribution part, 504 is a refrigerant outlet collection part, 550 is a plurality of inner pipes through which the refrigerant passes, 560 is a fitting for the antifreeze temperature sensing part 6a, 570 is an inner pipe 55
0 is inserted into the outer tube, 580 is the inner tube 550 and outer tube 5
70 and 760 is a fitting for the anti-freezing temperature sensing section 7a.

Next, in FIG. 9, 9 is the operation switch, 6
0 and 70 are antifreeze temperature detectors 6 and 7, respectively.
A is the contact of the electromagnetic contactor, A1 is the contact of the electromagnetic contactor A, B is the relay, and B1 and B2 are the contacts of the relay B, respectively.

In such a circuit, when the operation switch 9 is in the stop position as shown in the figure and the contacts 60 and 70 of the antifreeze temperature detectors 6 and 7 are on, respectively, the relay B is energized and its contact B1 is turned on. ,B
2 is also turned on, and a self-holding circuit of contacts B1, 60, 70 and relay B is formed.

Therefore, when the operating switch 9 is brought to the operating position, the contact B2 is on, so the electromagnetic contactor A is energized, the contact A1 is on, and the compressor 1 is started.

When either the anti-freeze temperature detector 6 or 7 is activated during operation of the compressor 1 and either the contact 60 or 70 is turned off, the relay B is demagnetized and its contacts B1 and B2 are respectively turned off. The compressor 1 then stops.

To restart the compressor 1, turn the operation switch 9
Once returned to the stop position, the activated antifreeze temperature detectors 6 and 7 are cut in, and their contacts 60 and 7 are closed.
After 0 is turned on, the operating switch 9 may be moved to the operating position as described above.

In such a chilling unit, first,
When the outside air temperature is about 15°C or higher and the engine is started after a stop period of more than one day and night, the temperature of the temperature sensor 7a (see Fig. 3) is as follows.
As shown in Fig. 10, the change is shown by the solid line during normal operation and the broken line during water outage, so if the cut-off setting _T1 of the antifreeze temperature sensor 7 is set as shown in the figure, the evaporation It is possible to prevent the container 5 from freezing, and there is no problem during normal operation.

Next, when the outside temperature is about 15 degrees Celsius or less or when the refrigerant amount is about 60% or less of the normal amount and the engine is started after a stop period of more than one day and night, the temperature change of the temperature sensing part 7a is shown in FIG. 11. Therefore, when the water in the evaporator 5 is cut off, it is impossible to prevent the evaporator 5 from freezing using only the cut-off value _T1 of the antifreeze temperature detector 7.

This is because when the outside air temperature is low, the condensation pressure in the condenser 2 is low, so the pressure is passed through the evaporator 5 through the pressure reducing valve 4.
When the refrigerant flow rate is less than about 60% of the appropriate value, it cannot be sufficiently condensed in the condenser 2, and a two-phase flow of liquid and gas occurs upstream of the pressure reducing valve 4, reducing the pressure. Since gas gets mixed into the valve 4, the evaporator 5 cannot be supplied with refrigerant at a much lower flow rate than the appropriate value.
This is because water begins to freeze near the intersection of the water inlet and the refrigerant inlet, which delays the temperature drop in the temperature sensing section 7a.

This is because when an appropriate amount of refrigerant flows in the condenser, the liquid refrigerant condensed between the inlet and the outlet is retained near the outlet, resulting in sufficient cooling and condensation, but when the refrigerant flow rate decreases, This is because the liquid refrigerant is no longer retained near the outlet, so the refrigerant passes through the condenser without being sufficiently cooled and condensed.

Therefore, in the present invention, in order to detect the temperature at the part of the evaporator 5 where freezing begins, as shown in FIG.
The temperature sensing portion 6a of the antifreeze temperature detector 6 is provided protrudingly on the opposite side of the outer tube 570 to the portion in contact with the inner tube 550 or in the vicinity thereof.

The temperature detected by the temperature sensor 6a installed in such a position is as shown in Fig. 12 when the outside air temperature is about 15 degrees Celsius or less, or the refrigerant is about 60% or less of the appropriate value, and at the time of startup after a stop period of more than one day and night. Since freezing starts at 0°C, the cut-off value of the anti-freezing temperature detector 6 can be set to a temperature _T2 that is 1 to 2°C higher than 0°C.

In short, according to the present invention, in a water cooler equipped with a refrigerant compressor, a condenser, a throttle mechanism, and an evaporator consisting of an inner pipe through which refrigerant flows and an outer pipe through which water flows, A temperature sensor attached to the outlet refrigerant pipe section of the evaporator, a temperature sensor attached to the inlet outer pipe section through which water flows through the evaporator, and a temperature detected by each of the above temperature detectors. By providing a means for cutting off the power to the refrigerant compressor motor when each of , the present invention is extremely useful industrially.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a known air-cooled chilling unit, Fig. 2 is a diagram showing the temperature of the evaporator shown in Fig. 1, Fig. 3 is a system diagram showing an embodiment of the present invention, and Fig. 4 is a partially enlarged view of the evaporator in FIG. 3, FIG. 5 is a sectional view taken along - in FIG. 4, FIG. 6 is a partially enlarged vertical sectional view of the refrigerant inlet portion in FIG. 8 is a cross-sectional view taken along lines - and - in FIG. 6, FIG. 9 is a circuit diagram showing the control system in FIG. 3, and FIGS.
In the diagram showing the temperature detected by the temperature sensing part 7a in the figure, Figure 10 shows the outside temperature when the outside temperature is 15°C or higher, and Figure 11 shows the outside temperature.
Fig. 12 is a diagram showing the temperature detected by the temperature sensor 6a in Fig. 3 when the outside air temperature is 15°C or below, or when the refrigerant amount is 60% or less of the normal flow rate.
Indicates when the amount is below or the amount of refrigerant is less than 60% of the normal amount. 1...Compressor, 2...Condenser, 3...Blower,
4... Pressure reducing valve, 5... Evaporator, 501... Water inlet section, 502... Water outlet section, 503... Refrigerant inlet distribution section, 504... Refrigerant outlet gathering section, 550... Inner pipe, 560... …Temperature-sensing part attachment, 570…Outer tube,
580...Water flow section, 6...Temperature detector for freezing prevention, 6a...Temperature sensing section, 60...Contact, 7...Temperature detector for freezing prevention, 7a...Temperature sensing section, 70... Contact, 760...Temperature sensing part attachment, 8...Accumulator, 9...Operation switch, 10...Refrigerant inlet pipe, 11...Refrigerant outlet pipe, 20, 21...Water side valve, A...Magnetic contact Device, A1...Contact, B...
Relay, B1, B2... contacts.

Claims (1)

[Scope of utility model registration request] In a water cooler equipped with a refrigerant compressor, a condenser, a throttle mechanism, and an evaporator consisting of an inner pipe through which refrigerant flows and an outer pipe through which water flows, the temperature sensing part is connected to the outlet refrigerant pipe of the evaporator. The detected temperature of each of the above temperature detectors is below the preset cut-off value. A water cooler comprising: means for cutting off power to the refrigerant compressor motor when: