Arrangement for cooling a plasma-based radiation source with a metal cooling liquid and method for starting up a cooling arrangement of this type

Patent metadata

Field	Value
Publication number	US-9581392-B2
Application number	US-201514633420-A
Country	US
Kind code	B2
Filing date	Feb 27, 2015
Priority date	Feb 28, 2014
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

An arrangement for cooling a plasma-based radiation source with a metal cooling liquid and a method for starting up a cooling arrangement of this type has a pump unit for conveying the metal cooling liquid from a reservoir to an immersion bath in a pipe portion that is connected to the reservoir in the conveying direction of the cooling circuit has at least one pump for conveying the metal cooling liquid through an external field effect of the at least one pump. A control unit for controlling the at least one pump controls the at least one pump at least temporarily in a pumping direction opposite to the conveying direction of the cooling circuit in order to generate a heating effect through external field effect on metal cooling liquid located in the pipe portion.

First claim

What is claimed is:

1. An arrangement for cooling a plasma-based radiation source with a metal cooling liquid comprising:
a revolving element to be cooled;
an immersion bath comprising the metal cooling liquid in which the revolving element is at least partially immersed;
a cooling circuit coupled to the immersion bath and comprising a reservoir for receiving a minimum volume of the metal cooling liquid;
means for maintaining the metal cooling liquid above a melting temperature, and at least one temperature sensor for monitoring a temperature of the metal cooling liquid; and
a pump unit for circulating the metal cooling liquid in the cooling circuit from the reservoir to the immersion bath, the pump unit being arranged in a pipe portion connected to the reservoir in a conveying direction of the cooling circuit, the pump unit comprising at least one pump in the pipe portion for conveying the metal cooling liquid through an external electromagnetic field of the at least one pump, and in that a control unit is provided for controlling the at least one pump, the control unit operating the at least one pump at least temporarily in a pumping direction opposite to the conveying direction of the cooling circuit for generating a heating effect in the metal cooling liquid located in the pipe portion against a flow resistance of the metal cooling liquid in the pipe portion affected by the external electromagnetic field.

2. The arrangement according to claim 1 , wherein the at least one pump is arranged at the pipe portion of the cooling circuit, the pipe portion being disposed below a minimum fill level predetermined by a minimum volume of the metal cooling liquid in the reservoir.

3. The arrangement according to claim 1 , wherein the flow resistance of the metal cooling liquid in the pipe portion is generated by the metal cooling liquid stored in the reservoir.

4. The arrangement according to claim 1 , wherein the pump unit comprises at least one first pump and at least one second pump, wherein the at least one second pump is disposed in the pipe portion upstream of the at least one first pump from the direction of the reservoir, wherein if more second pumps than the at least one second pump are used, each second pump is disposed upstream of the at least one first pump.

5. The arrangement according to claim 4 , wherein the flow resistance in the pipe portion is generated by the at least one second pump operated in the conveying direction when the at least one first pump operates in an opposite direction to the conveying direction of the cooling circuit.

6. The arrangement according to claim 4 , further comprising additional first pumps and additional second pumps in the pump unit, the additional first and second pumps being controllable separately by the control unit such that at least all of the first pumps can be operated with pumping in the opposite direction to the conveying direction.

7. The arrangement according to claim 1 , all of the pumps in the pump unit are induction pumps.

8. The arrangement according to claim 1 , wherein the control unit is provided for monitoring and adjusting an operating temperature of the metal cooling liquid above the melting temperature thereof, wherein the control unit uses at least one temperature sensor provided in the cooling circuit to initiate a heating mode when the temperature drops below an operating temperature of the metal cooling liquid and to initiate a cooling mode when the operating temperature is exceeded.

9. The arrangement according to claim 8 , further comprising a heater which can be switched on by the control unit in the heating mode to heat the metal cooling liquid in the reservoir.

10. The arrangement according to claim 9 , wherein the heater is arranged in the reservoir in such a way that when the heater is dipped into the reservoir, the heater melts the metal cooling liquid from top to bottom.

11. The arrangement according to claim 10 , wherein the heater is divided into separate heating circuits which can be controlled separately for melting the metal cooling liquid in the reservoir by layers from top to bottom.

12. The arrangement according to claim 11 , further comprising an additional heater for the immersion bath.

13. The arrangement according to claim 8 , further comprising at least one heat exchanger arranged upstream of the immersion bath and switchable by means of the control unit in the cooling mode for cooling the metal cooling liquid to a temperatures below a determined maximum operating temperature of the metal cooling liquid, the heat exchanger is controllable to maintain a determined minimum operating temperature above the melting temperature of the metal cooling liquid during cooling.

14. The arrangement according to claim 13 , wherein the heat exchanger can be switched on as a heater when the temperature of the metal cooling liquid is below the melting temperature or approaching below the determined minimum operating temperature, wherein the heat exchanger comprises a secondary cooling circuit with a coolant which has a minimum temperature above the melting temperature of the metal cooling liquid.

15. A method for cooling a plasma-based radiation source with a metal cooling liquid, the method comprising:
heating the metal cooling liquid solidified in a reservoir of a cooling circuit with a heater starting from a maximum fill level of the metal cooling liquid in a direction to a deepest point of the reservoir, thereby melting the metal cooling liquid;
melting the metal cooling liquid solidified in a pipe portion connected to the reservoir by means of an external electromagnetic field of at least one pump which is arranged in the pipe portion and which is temporarily operated during the melting in a pumping direction opposite to a predefined conveying direction of the cooling circuit; and
heating the entire cooling circuit to an operating temperature above a melting temperature of the metal cooling liquid by switching the at least one pump to the predefined conveying direction of the cooling circuit, therefore conveying the metal cooling liquid out of the reservoir into the cooling circuit by means of the at least one pump arranged in the pipe portion.

16. The method according to claim 15 , further comprising adjusting the at least one pump temporarily operated opposite to the conveying direction of the cooling circuit to a maximum flow rate in the conveying direction of the cooling circuit.

17. The method according to claim 15 , wherein carrying out switching of the at least one pump from a pumping direction temporarily directed opposite to the conveying direction to the conveying direction of the cooling circuit occurs when a required operating temperature of 5-70 K above the melting temperature of the metal cooling liquid is reached in the pipe portion connected to the reservoir.

18. The method according to claim 17 , wherein adjusting the at least one pump after switching from temporarily operating opposite to the conveying direction to cooling operation in the conveying direction is carried out to a minimum flow rate at which a predetermined operating temperature of the metal cooling liquid in the cooling circuit is achieved.

19. The method according to claim 15 , further comprising pumping the at least one pump operated opposite to the conveying direction against at least one second pump operated in the conveying direction to melt the metal cooling liquid solidified in the pipe portion connected to the reservoir, wherein the at least one second pump is adjusted to operate at a

Assignees

• Ushio Electric Inc

Inventors

• Niimi Gota
• Vaudrevange Dominik Marcel
• Conrads Ralf Gordon
• Kole Maghiel Jan

Classifications

• F28F23/00

  Features relating to the use of intermediate heat-exchange materials, e.g. selection of compositions (heat-transfer, heat-exchange or heat-storage materials C09K5/00) · CPC title

• F28D15/00 Primary

  Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls {; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies (F28D17/00, F28D19/00, F28D20/00 take precedence)} · CPC title

• H05G2/002

  Supply of the plasma generating material · CPC title

• F28F5/02 Primary

  Rotary drums or rollers · CPC title

• H05G2/005

  Electricity · mapped topic