DE2938086B1 - Temperature sensor for determining the coolant temperature in liquid-cooled transformers - Google Patents

Description

Claims: 1. Temperature sensor for determining the coolant temperature in coolant inlet and outlet pipes of liquid-cooled transformers, whereby thermocouples are arranged in the center of the coolant flow, d a d u r c h g e - indicates that each of the thermocouples (1) is transversely in the coolant flow (2) held metallic grid (3) is supported, - that the grid (3) the coolant temperature transmits to the thermocouple (1) and - that the ends (4) from spoke-like to outer webs of the grid (3) embedded in a sealing ring (5) are.

2. Temperature sensor according to claim 1, characterized in that the grid (3) arched like a basket and in the coolant flow (2) immediately before or is arranged behind a throttle valve.

3. Temperature sensor according to claim 1 and 2, characterized in that that the grid (3) in one piece and the cross-section of its webs approximately square is.

4. Temperature sensor according to claims 1 to 3, characterized in that that the grid (3) is punched out of a copper disk.

5. Temperature sensor according to claims 1 to 4, characterized in that that the cross section of the webs decreases radially outward and that of the sealing ring encompassed web ends (4) run out to a point.

6. Temperature sensor according to claims 1 to 5, characterized in that that the electrical connection conductor (8) of the thermocouple (1) from one of the webs are worn.

7. Temperature sensor according to claims 1 to 6.

characterized in that the sealing ring carrying the grille (3) (5) consists of thermally and electrically insulating material.

The invention relates to temperature sensors for determining the coolant temperature in coolant inlet and outlet pipes of liquid-cooled transformers, whereby Thermocouples are arranged in the center of the coolant flow.

For monitoring, controlling and / or regulating transformers it is often necessary to record the coolant temperature. To this end were previously thermocouples hanging freely on cables, wires or cords in the coolant flow been used.

However, this is particularly true at the inlet and outlet of the coolant flow in a recooling device is unsatisfactory because throttle valves are often used at these points are provided. With regard to the necessary to pivot the throttle valve In these cases, the thermocouples must be off-center and often also in the shadow of the flow the throttle valve itself. The consequence of this is often not temperature measurement taking place with sufficient accuracy.

The invention is now based on the object for use in coolant pipes of re-cooling equipment to create a temperature sensor for transformers, which even when installed near throttle valves or other the flow of the Components influencing coolant are reliable in relation to the flow cross-section the mean coolant temperature is detected.

According to the invention this object is achieved in that each of the Thermocouples from a metallic grid held transversely in the coolant flow is supported that the grid transmits the coolant temperature to the thermocouple and that the ends of webs of the grid extending outward like spokes in a sealing ring are embedded.

According to appropriate embodiments of the invention it is provided that the grid arched like a basket and punched in one piece from a copper disc is, the cross-section of the webs is approximately square.

Other embodiments of the invention consist in that the cross section the webs decrease radially outwards and the web ends encompassed by the sealing ring to a point that the electrical connection conductor of the thermocouple of a of the webs are supported and that the sealing ring carrying the grille is made of thermal and electrically insulating material.

The temperature sensor according to the invention is very advantageous because it connects a mechanically reliable holder of the thermocouple with a at the same time in a simple way very effective temperature transfer from the to monitoring coolant flow to the thermocouple.

An embodiment of the invention is based on a drawing explained in more detail.

F i g. 1 shows a plan view and FIG. 2 a cross section by a temperature sensor constructed according to the invention.

In the center of a grid 3 made of spoke-like webs is a thermocouple 1 attached for example by soldering. The free ends 4 of the bars of the grid 3 are anchored in a sealing ring 5.

The sealing ring 5 is used in the usual way to seal the connection point of two pipe ends 6 and 7. To be provided for a throttle valve provided near the pipe end 6 To create the necessary swivel space, the grid 3 is curved like a basket. An outgoing from the thermocouple 1 electrical connection conductor 8 is through the Sealing ring 5 guided radially outward and is optionally supported in the Area between the thermocouple 1 and the sealing ring 5 on one of the webs of the grid 3.

A coolant flow 2 flows around the webs of the grille 3, so that this assume the temperature of the coolant. The heat conduction in the Bars themselves are the mean value of the temperature of the coolant.

Claims (1)

For this purpose, the grid 3 is made of a material with essential produced better thermal conductivity than the coolant. The grid 3 is therefore preferably punched out of copper or aluminum sheet. As a result of the good The thermal conductivity of the grille 3 becomes the mean coolant temperature of this transferred to the thermocouple 1 with a negligibly small time delay and from this immediately after conversion into an analog electrical quantity passed on to an evaluation device, not shown.