SU802941A1 - Constant-temperature cabinet - Google Patents

Description

The invention relates to the field of temperature control of REA elements and is intended for use in thermostats with forced heating.

Known thermostatic devices containing forced heating systems And and [2]. The afterburner power off in these devices can occur at temperatures below the static temperature, and the trip point is not adjusted depending on the ambient temperature. This is the main reason for the impossibility of optimizing the process of thermostat entering the mode, especially in a wide range of ambient temperatures. '

The closest technical solution is a thermostat containing a heat-insulating casing with a thermostatic chamber installed in it, in which a thermosensitive element connected with the control unit and boost heaters are placed [3].

However, when the afterburner heater is turned off, the temperature of the thermostat chamber is practically independent of the ambient temperature. This leads to a significant increase in the time of heating the object (V _o g) to the temperature of stating, especially at minimum ambient temperatures _, since during the operation of the afterburner system the object does not manage to get enough energy for heating due to the thermal inertia of the object and the presence of thermal resistance between it and the thermostat chamber. The aim of the invention is to reduce the time to reach the temperature regime.

This is achieved by the fact that a heat sink is installed in the thermostat on a thermostatically controlled chamber, on the outer part of which is located outside the chamber a movable heat-insulating plate is placed, and on the inside there is an adjustable heater and a heat-sensitive element.

In FIG. 1 shows a thermostat in section; in FIG. 2 - view from above; in FIG. 3 and 4 are graphs of the temperature (T) versus time ^);

The thermostat contains a thermosensitive element 1, an afterburner heating system installed through an insulating pad 2 on a thermostatically controlled chamber 3. The thermosensitive element is connected to the environment through a heat sink 4 made of a material with high thermal conductivity, passing through the heat-insulating casing 5 of the thermostat.

The outer part of the heat sink 4 is made in the form of a half ring. The change in thermal resistance between the heat-sensitive element and the environment is carried out using a movable heat-insulating plate b with a groove for heat sink 4.

The required position of the heat-insulating plate b is fixed by means of a screw 7, which simultaneously is the axis of rotation of the plate 6. An adjustable heater 8 is wound on the inside of the heat sink 4. It is connected through a potentiometer 9 to the power supply circuit of the boost heaters 10. The control unit in the drawing shown.

This design allows you to change the heating speed of the heat-sensitive element, and consequently, the operation mode of the afterburner system depending on the ambient temperature, since in the process of setting such a position of the heat-insulating plate ό on the heat sink 4 and such power on the adjustable heater 8 at which the boost heaters are turned off 10 in the process of exiting the thermostat to the mode occurs at the optimum value of overheating. Optimum is overheating, in which, after turning off the boost heaters 10, the time of their cooling to the set temperature is equal to the time the object is heated to the same temperature.

After finding the optimal position of the heat-insulating plate 6 corresponding to the minimum heating time of the object, it is fixed with a screw 7.

The invention can significantly reduce the time the thermostat enters the mode, since the object in this case receives a higher heating power (see graphs in Figs. 3, 4) and the time the thermostat enters the mode is reduced by 30% or more.

Claims (3)

one . . The invention relates to the field of thermostating of CEA elements and is intended for use in thermostats with forced heating. Thermostating devices are known that contain forced heating systems ij and 2. Disconnecting the power supply of the boost in these devices can occur at temperatures below the setting temperature and the disconnection point is not corrected depending on the temperature surrounding. This is the main reason for the impossibility of optimizing the process of thermostat output to the mode, especially in a wide range of ambient temperatures. The closest technical solution is a thermostat containing a heat insulating casing with a thermostatically controlled chamber installed in it, in which a temperature-sensitive element associated with the control unit and forcing heaters 3 are placed. However, when the afterburner disconnects, the temperature of the thermostat chamber is almost independent of the ambient temperature. This leads to a significant increase in the time of heating the object () to the setting temperature, especially at minimum ambient temperatures, since after the operation of the afterburner system the object does not have time to receive sufficient energy for heating due to the thermal inertia of the object and the high thermal resistance between him and the thermostat chamber. The aim of the invention is to reduce the time to reach the temperature regime. This is achieved by the fact that a heat sink is installed on the thermostatically controlled chamber in the terrain, on the outside of which, located inside the chamber, there is a movable heat insulating plate, and on the inside there is an adjustable heater and temperature sensitive element. FIG. 1 shows a thermostat in section j in FIG. 2 is a top view of it in FIG. Tables 3 and 4 show graphs of the temperature (T) bridges from time to time (CJ; The thermostat contains a temperature-sensitive element 1 of the force-heating system installed through an insulating gasket 2 on a thermostatically controlled chamber 3. The temperature-sensitive element 1 is connected to the environment through a heat sink 4 from a material with high thermal conductivity, passing through the heat-insulating casing 5 thermostat The external part of the heat sink 4 is effected in the form of a half-ring. The change in thermal resistance between the thermal sensing element and the environment is It is supported by a movable heat insulating plate b with a groove for the heat sink 4. The required position of the heat insulating plate b is fixed by means of a screw 7, which is also the axis of rotation of the plate 6. On the inside of the heat sink 4 is wound an adjustable heater 8, which the potentiometer 9 connected to it is connected to the power supply circuit of the forcing heaters 10 The control unit in the drawing is not shown This design allows to change the heating rate of the temperature-sensitive element nta, and consequently, the mode of operation of the system and the afterburner, depending on the ambient temperature, since the tuning process determines the position of the heat insulating plate 6 on the heat sink 4 and such power on the controlled heater 8 at which the forcing heaters disconnect 10 The process of thermostat entering the mode occurs at an optimal overheating value. The best is overheating, at which after shutdown of the forcing heaters 10, their cooling time to the temperature of the scrubber is equal to the time of heating the object to the same temperature. After finding the optimal position of the heat insulating plate 6 corresponding to the minimum warm-up time of the object (LQJ ii.) I is fixed with a screw 7. The invention significantly reduces the time for the thermostat to go into operation, since the object in this case receives a higher heating power (see graphs in Figs. 3, 4) and time Thermostat output to mode is reduced by 30% or more. The invention The thermostat containing a heat-insulating casing with a thermostatically controlled chamber installed in it, on which is placed a temperature-sensitive element connected to the control unit and boost heaters, which is installed in order to reduce the thermostat's time to temperature setting. a heat sink, on the outer part of which, located outside the chamber, is placed a movable heat-insulating plate, and on the inside, an adjustable heater and those are installed Sensitive element. Sources of information taken into account during the examination 1. USSR author's certificate 331374, cl. G 05 D 23/19, 1972. 2. USSR author's certificate number 481127, cl. H 03 K 5/18, 1975. 3. Thermostat to stabilize the temperature of the ultrasonic delay line. Information leaflet VINI number 76-0772, 1976 (prototype). x ± g- // Afterburner nutrition  I Tokr (LIN Shykt Aotchik Camera they are tale Object Natchik Camera