JPS58164973A - Defroster - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a defrosting device for products in which frost adheres to and grows on a heat exchanger, and is installed so that the temperature sensing part of the thermostat □ is kept at a constant distance from the surface of the heat exchanger. By doing so, the purpose is to sense the timing of defrosting and the end of defrosting, and automatically repeat the defrosting-dehumidifying operation.

Conventionally, the defrost timing sensing device in dehumidifiers, etc.2.
In many cases, the temperature sensing part 134 of the thermostat 125 is embedded in the fins 400 of the heat exchanger 115 to sense the temperature, and the fins 400 of the heat exchanger 115 change.
In addition, it has the disadvantage that it takes a considerable amount of man-hours to securely fix it. Furthermore, as shown in FIG. 5, the temperature of the evaporator 115 after a certain period of time after the start of dehumidifying operation varies depending on the ambient temperature during operation, so in the defrosting method that senses the temperature of the heat exchanger, the thermostat 125 is activated. If the temperature is set to the optimum temperature at a certain ambient temperature, it will not defrost properly at other temperature ranges, and the defrost timing will not be consistent due to variations in the set temperature of the thermostat 125. To solve this problem, methods such as inserting a timer or the like into the circuit have disadvantages such as high cost and increased assembly man-hours.

The present invention solves the above-mentioned conventional drawbacks, and embodiments thereof will be described below with reference to FIGS. 4 and 15.

In the refrigeration circuit shown in Figure 6 on page 3, the flow of refrigerant during dehumidification operation starts from the compressor 11, passes through the solenoid valve 12, passes through the condenser 13 and resistance pipe 14, and generates dew and frost in the evaporator 15. ,
Return to the compressor 11 again. During defrosting, the refrigerant discharged from the compressor 11 flows directly from the solenoid valve 12 into the evaporator 15 as hot gas, melts the frost with its heat, and returns to the compressor 11.

During zero dehumidification operation, the electrical operation of which is explained in FIG. 7, the electrical circuit becomes as shown in FIG. The wind generated by the flow. When frost is detected and the thermostat 25 is activated, the state shown in FIG. 8 occurs, the power to the fan motor 23 is cut off and the solenoid valve coil 2
4 is energized, the solenoid valve 12 is activated, and defrosting is performed.

When defrosting is finished and the temperature of the evaporator 16 rises, the temperature sensing part 34 of the thermostat 26 warms up and the contact returns to normal.
The state shown in Fig. 7 is reached, dehumidification operation is started, and the above operations are repeated.

The temperature sensing portion 34 of the thermostat 26 is inserted into a fixed holder 31 as shown in FIGS. 9 to 11, and its movement in all directions, vertically and horizontally, is restricted and fixed. Furthermore, the fixed holder 31
When the slotted portion 32 of the evaporator 16 is press-fitted into the pipe portion 36 of the evaporator 15 as shown in FIGS.
5 and the lower rib surface 33 of the fixed holder 31 are fixed in contact with each other, thereby keeping the distance H between the temperature sensing portion 34 of the thermostat 25 and the upper surface 35 of the evaporator 15 constant.

As the frost grows, the temperature sensing part 34 of the thermostat 25
When the frost approaches and grows at a distance H4, the temperature sensing portion 34 comes into contact with the frost, and the temperature of the temperature sensing portion 34 drops rapidly.

Now, the ambient temperature of the main unit during operation is tl, and the frost sensing set temperature of the thermostat 26 is t2. Defrost end sensing temperature t3
and the frost temperature is 14.

When the main body is dehumidified under the temperature condition of - tl>t22, the air at temperature t1 blows into the temperature sensing part 3, as shown in Fig. 15A.
4 and is sucked into the evaporator 16.

Even if frost 4o gradually grows, as shown in Figure 15,
Since the air having the temperature t1 passes through the temperature sensing section 34, the thermostat 26 does not operate, and the dehumidification operation continues. As frost 4o grows and frost temperature t4, thermostat 2
When the temperature of the temperature sensing section 34 of No. 6 reaches the frost sensing temperature it2,
The thermostat 25 operates and defrosting operation begins. At this time, the fan motor 23 stops, the evaporator silk 40 melts, and the temperature of the temperature sensing part 34 of the thermostat 25 rises.
When the temperature reaches 3, the thermostat 25 is reset, defrosting is completed, and dehumidifying operation is resumed, and the above operation is automatically repeated as shown in FIG. 16.

The defrosting cycle is related to the growth rate of frost, so if you want to shorten it, you can shorten the distance H between the temperature sensing part 34 of the thermostat 25 and the surface 35 of the evaporator 15.
On the other hand, in order to lengthen the defrosting cycle, H may be increased.

The setting of H can be easily changed by changing the shape of the fixed holder.

Furthermore, since there is usually a difference between the ambient temperature t1 during operation and the frost temperature t4, even if there is some variation in the setting of the frost sensing temperature of the thermostat 25, the magnitude of the variation is less than or equal to Ct4-tl). If so, it will operate without any malfunction.

For example, when the operating temperature is 1°C or higher, the thermostat can operate normally even if the set temperature varies within a range of -1.5±2°C.

As described above, according to the present invention, the distance between the temperature sensing part of the thermostat and the surface of the heat exchanger can be kept constant by simply inserting the temperature sensing part of the thermostat into the fixed holder and press-fitting the fixed holder into the heat exchanger. Automatic defrosting is achieved with little influence from changes in ambient temperature or thermostat set temperature, and the frequency can be easily changed by changing the height of the temperature sensing part of the fixed holder. It is effective.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing the mounting state of the thermostat in one conventional embodiment, FIGS. 3 and 4 are explanatory diagrams showing the mounting state of the thermostat in another conventional embodiment, and FIG. is a characteristic diagram showing the ambient temperature and the temperature of the evaporator for a certain period of time after dehumidifying operation. Figure 6 is a cooling circuit diagram of the dehumidifier in one embodiment of the present invention. Circuit diagram, Figure 8 is an electric circuit diagram showing the thermostat in the switched state, Figure 9 is a top view of the fixing holder, and Figure 1 is the fixing holder showing the thermostat with the temperature sensing part attached. A side view of the holder, Fig. 11 is a sectional view taken along the line A-B in Fig. 1, and Fig. 12
The figure is a front view of the heat exchanger with the temperature sensing part of the thermostat attached, Figure 13 is a side view of the heat exchanger, Figure 14 is a sectional view taken along line C-D in Figure 12, and Figure 15 is a side view of the heat exchanger. FIG. 16 is an explanatory diagram showing changes in frost formation, and FIG. 16 is a characteristic diagram showing temporal changes in temperature at the temperature sensing part of the thermostat. 12... Solenoid valve, 16... Evaporator, 2
5...Thermostat, 31...Fixed holder, 34...Temperature sensing section. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure f34 Figure 5

Claims (1)

[Claims] The thermostat has a thermostat and a solenoid valve, and the thermostat is placed in a fixed holder at a predetermined distance from the heat exchanger, and the solenoid valve is arranged so that the temperature-sensing part of the thermostat comes into contact with frost that has grown from the heat exchanger. A defrosting device that is connected to the thermostat so that it can be activated by □ when approached, and the solenoid valve is located in a position that allows hot gas from the refrigeration circuit to flow into the frosted evaporator when activated.