SU765703A1

SU765703A1 - Method of feeding cooling agent

Info

Publication number: SU765703A1
Application number: SU782681029A
Authority: SU
Inventors: Эдуард Михайлович Райбман
Original assignee: Научно-Исследовательский И Конструкторский Институт Испытательных Машин,Приборов И Средств Измерения Масс
Priority date: 1978-11-02
Filing date: 1978-11-02
Publication date: 1980-09-23

Description

(54) СПОСОБ ПОДАЧИ ХЛАДАГЕНТА(54) METHOD FOR SUPPLY COOLANT

II

Изобретение относитс к испытательной технике , а именно к способам подачи хладагента при испытани х материалов при низких температурах .The invention relates to a testing technique, in particular, to methods for supplying a refrigerant when testing materials at low temperatures.

Известен способ подачи хладагента из сосуда Дьюара к испытуемому объекту, заключающийс в том, что хладагент нагревают с помощью проволочного нагревател , расположенного на конце трубопровода в сосуде Дьюара, и вытесн ют его по трубопроводу в испытуемый объект за счет избыточного давлени , образующегос в сосуде при интенсивном испарении хладагента 1.A known method of supplying refrigerant from a Dewar vessel to a test object is that the refrigerant is heated using a wire heater located at the end of the pipeline in the Dewar vessel and displaces it through the pipeline to the test object due to the overpressure generated in the vessel under intense pressure. refrigerant evaporation 1.

Недостатком способа вл етс отсутствие контрол за уровнем хладагента.The disadvantage of this method is the lack of control over the level of the refrigerant.

Наиболее близким по технической сущности к предлагаемому вл етс способ, заключающийс в том, что хладагент нагревают, вытесн ют из сосуда Дьюара за счет давлени паров хладагента и контролируют уровень хладагента в сосуде с помощью термочувствительного злемента, установленного на нагревателе. Сигнал с термочувствительного злемента используют дл сигнализации о расходе хладагента, а также дл автоматического переключени на резервный сосуд Дьюара с целью бесперебойной подачи хладагента в испытуемый объект. В качестве термочувствительного элемента используют терморезисторы, а дл уменьшени инерционности термочувствительнсго элемента и увеличени быстродействи коммутирующих и сигнальных каналов термочувствительный элемент снабжают дополнительным нагревателем 2.The closest in technical essence to the present invention is the method consisting in that the refrigerant is heated, displaced from the Dewar vessel due to the vapor pressure of the refrigerant and controls the level of the refrigerant in the vessel using a temperature-sensitive element installed on the heater. The signal from the temperature-sensitive element is used to signal the refrigerant flow rate, as well as to automatically switch to the reserve Dewar vessel in order to ensure uninterrupted supply of the refrigerant to the test object. Thermistors are used as a thermosensitive element, and to reduce the inertia of the thermosensitive element and increase the speed of the switching and signal channels, the thermosensitive element is supplied with an additional heater 2.

10ten

Недостаток этого способа - его сложность, так как дл его реализации необходимы нагреватель, термочувствительный элемент и дополнительный нагреватель на термочувствитель15 ном элементе, а также усиленна электрическа изол ци как между указанными узлами, так и между ними и корпусом.The disadvantage of this method is its complexity, since its implementation requires a heater, a temperature-sensitive element and an additional heater on a temperature-sensitive element, as well as reinforced electrical insulation both between the indicated nodes and between them and the housing.

Цель изобретени - упрощение способа.The purpose of the invention is to simplify the method.

Поставленна ц.ель достигаетс тем, что на20 грев осуществл ют подачей напр жени на термочувствительный элемент.The delivered aim is achieved by the fact that the heating is carried out by applying a voltage to the thermosensitive element.

Claims

The drawing shows a device for implementing the method of supplying refrigerant. 3 The device contains a Dewar vessel 1 with liquid refrigerant 2, a pipeline 3 placed in the vessel 1, sealed with a sealing plug 4. At the outer end of the pipeline outside the Dewar vessel 1 a control unit 5 is mounted and a fitting 6 for connecting the device with the object to be cooled (not shown ). The heater 7 is located at the other end of the pipeline 3 inside the vessel 1 and at the bottom of the latter, made in the form of one or more temperature-sensitive elements (for example, thermistors). The number and scheme of connection of thermosensitive elements are chosen based on the required heating power, parameters of the power circuit and characteristics of thermosensitive elements. The terminals 8 of the heater 7 are connected to the control unit 5 and connected directly to the power circuit. Pipe casing 3 can be used as one of the conclusions. The method is carried out as follows. Voltage is supplied to the heater 7 to supply refrigerant 2 from the Dewar vessel 1 to the cooled object. Due to the cooling effect of the refrigerant, it is possible to apply power to the heater that is much higher than the permissible temperature. The heat released by the heater 7 causes intense evaporation of the liquid refrigerant, which leads to an increase in the vapor pressure of the refrigerant. Under the action of this pressure, the liquid refrigerant is transported through conduit 3 from the Dewar vessel through the urrytser 6 to the cooled object. As soon as the coolant level in the vessel 1 drops below the level of the heater 7, the heat dissipation from the latter will sharply decrease, and the temperature UNDER influenced by the current flowing through it will increase, which will lead to a jump in resistance and current. With a sudden change in current in control unit 5, a signal is generated that is used for emergency shutdown of the thermosensitive element, issuing a signal on the total refrigerant flow rate and, if necessary, for switching to the backup refrigerant supply unit. The simplicity of the method is due to the fact that a temperature-sensitive element is used as a heater. In addition to TorOj, the method allows to increase the speed of the operator's warning system and the switching off of the temperature-sensitive element at full refrigerant consumption. The claims, the method of supplying the refrigerant from the Dewar vessel to the test object, is that the refrigerant is heated, displaced from the Dewar vessel by the vapor pressure of the refrigerant and control the level of refrigerant in the vessel using a temperature-sensitive element, which, in order to simplify In this way, the heating is carried out by applying a voltage to the temperature sensing element. Sources of information taken into account in the examination 1.Novikov I.V. and others. Devices for mechanical testing of structural Materials at low temperatures. Kiev, Naukova Dumka, 1968, p. 47

2. Author's certificate of the USSR N2 469074, cl. G 01 N 3/18, 1975 (prototype).

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