FIELD OF THE INVENTION:
The invention relates to a system of gas distribution and cooling of high temperature superconducting (HTSC) rotating machines like motors/generators.
BACKGROUND OF THE INVENTION AND PRIOR ART:
The typical operating temperature of the 1st generation HTSC conductor is 25-40K and for the 2nd generation conductor it is little higher, probably in the range of 50-65 K but lower than the liquid nitrogen temperature i.e. ~ 77K. For an HTSC machine using the above super conductors in field coils, there is enormous amount of heat load from atmosphere because of difference between room temperature and operating temperature of field coils of HTSC machine. This heat load is due to radiation, solid/gas conduction and fluid convection from adjacent regions or structures. The heat load can also be internally generated in the system from sources such as ac losses, eddy current in conductors etc.
PRIOR ART
US 7667358 B2: In this patent Inventors described cooling structure of a superconducting motor in which a superconducting coil is attached to a rotor, grooves are concavely provided on an outer surface of a rotating shaft that penetrates and is

fixed to the rotor. A refrigerant is circulated through a refrigerant circulation pipe disposed inside the grooves to that the superconducting coil is cooled by the refrigerant.
US20120274161A1: This patent relates to the structure of the superconducting rotor core. In this method, superconducting field coils are mounted on rotor core. The rotor core is made of a heavy solid member. The rotor core comprises rod like members and each coaxially disposed in the cryogen passage for effective cooling of field coils.
US20140217850A1: In this invention the superconducting coils are mounted with yoke and bobbin with fibre connection type arrangement for avoiding conducting type heat in lead. Inventor used this method for better cooling effect to superconducting coils which is achieved with low heat in leak through conduction.
OBJECTS OF THE INVENTION:
The object of the invention is to develop a system for effective cooling of high temperature super conducting rotating machines.
Another object of the invention is to develop a method for distribution of refrigerant gas to cool all the rotating housings of the field coils.

Further object of the invention is to ensure minimum leakage of heat during cooling process.
Still another object of the invention is to ensure least drop in gas pressure during cooling.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figure 1: Block diagram of gas flow circuit
101-Cryocooler
102-Cold gas pipe to rotating coupling
103-Rotating coupling
104-Cold gas pipe to cold gas sub-header
105-Cold gas sub-header
106-Cold gas pipes to cold gas main-header
107-Cold gas main-header
108-Cold gas pipes to superconducting coils
109-Chamber of superconducting coils
110-Warm gas pipes to Warm gas main-header
111-Warm gas main-header
112-Warm gas pipes to Warm gas sub-header
113-Warm gas sub-header

114-Warm gas pipe return to rotating coupling 115-Warm gas pipe return to cryocooler
Fig.2 Sectional view of assembly of pole coil housing with gas flow circuit
201-Input cold gas pipe
202-Cold gas sub-header
203-Cold gas pipe connecting cold gas sub-header to cold gas main-header
204-Cold gas main-header
205-Cold gas main-header ceiling plate
206-Cold gas pipe connecting cold gas main-header to each pole coil housing
207-Rotating sleeve
208-Pole coil housing
209-Warm gas pipe connecting each pole coil housing to warm gas main-header
210-Warm gas main-header
211-Warm gas pipes connecting warm gas main-header to warm gas sub-header
212-Warm gas sub-header
213-Warm gas return pipes
Fig.3 Sectional view of flow of cold gas to HTSC field coils
301-Input cold gas 302-Cold gas sub-header

303-Cold gas flowing from cold gas sub-header to cold gas main-header
304-Cold gas main-header
305-Cold gas entering main-header
306-Cold gas pipe connecting cold gas main-header to each pole coil housing
307-Rotating sleeve
308-Flow of cold gas in field coil housing
Fig.4 Sectional view of flow of warm gas from HTSC field coils
401-Rotating sleeve
402-Return gas flow in field coil housing
403-Warm gas flow in pipe connecting each pole coil housings to warm gas main-header
404-Warm gas main-header
405-Warm gas flow in pipes connecting warm gas main-header to warm gas sub-header 406-Warm gas sub-header 407-Warm gas return pipes to coupling
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT:
Fig.1 represents the block diagram of main component of the HTSC rotor and also gas flow direction through each components. The rotating coupling 103 transfer the cold

gas 102 from cryocooler 101 to the inlet gas line 104. The cold gas sub header 105 transfer the cold gas at three different positions 106 in the main header 107. The main gas header 107 feed the cold gas to the pole coil housing mounted on a chamber 109 through inlet connections 108. After cooling the filed pole coils the return gas collects in warm gas main header 111 through the outlet connects 110. Further the return gas goes to the warm gas sub header 113 from different positions 112. The rotating coupling 103 feed the return gas 114 to the cryocooler 101 through return line connection 115.
Fig.2 represents the sectional view of assembly of pole coil housing with gas flow circuit. Cooling gas from rotary coupling enters the cold gas sub-header 202 from inlet cold gas pipe 201. Sub header concept allows the uniform distribution of cold gas to all superconducting coils in a multi-pole HTSC motors. Three numbers of cold gas pipes 203 connects cold gas sub-header to cold gas main-header 204. Cold gas main-header ceiling plate 205 acts as a lid to this main header. For each superconducting pole coil, cold gas pipes 206 connects cold gas main-header to each pole coil housings 208. These superconducting pole coils are fastened on rotating sleeve 207. Warm helium pipes 209 connects each pole coil housings to warm gas main-header 210. Then another warm gas pipes 211 connects warm gas main-header to warm gas sub-header 212. FromWarm gas return pipes 213 allow the warm gas to go back to rotary coupling and then to cryocooler.

Fig.3 represents the sectional view of flow of cold gas into the HTSC field coils. The cold gas discharged from rotary coupling 103 enters in the cold gas sub-header 302 through inlet connection 301. The cold gas main header 304 is connected with cold gas sub-header with three cold gas pipes 303. The cold gas flows from cold gas sub-header and reaches to cold gas main header. The cold gas 305 flows from cold gas main header to field coil housings 308 through cold gas connections 306.
Fig.4 represents the sectional view of flow of warm gas from HTSC field coils. These superconducting field coils housings are fastened on rotating sleeve 401. After cooling the field coils, cooling gas 402 becomes warm. The return warm gas reaches to warm gas main header 404 through outlet gas connections 403 of field coil housings. Further this warm gas 405 gets collected in warm gas sub-header 406. The warm gas from warm gas sub-header flows through the outlet gas connections 407 of warm gas sub-header to rotary coupling 103. Further from rotary coupling, the warm gas flow to stationary cryocooler 101. Thus it completes one cooling cycle. This cooling cycle repeats till the field coils reach to its operating temperature i.e. 40K or until the HTSC machine operates for desired time.

WE CLAIM
1. A system of refrigerant gas distribution and a method of cooling for high
temperature super conducting (HSTC) rotor of a rotating machine, i.e. generator or
motor comprising:
a) cryocooler (101)
b) rotating coupling (103)
c) cold gas sub-header (105)
d) main header (107)
e) chamber for mounted coil housing (109)
f) warm gas main header (111)
g) warm gas sub-header (113)
Characterized by uniform distribution of cold gas through sub-header (202) to all super conducting coils in multipole HSTC motor/generator.
2. The system as claimed in claim 1, wherein three members cold gas pipes (203) connects cold gas sub-header to cold gas main header (204), wherein cold gas main header ceiling plate (205) acts as a lid to this main header.
3. The system as claimed in claim 2, wherein cold gas pipes (206) connects cold gas main header to each pole coil housings (208).

4. The system as claimed in claim 3, wherein super conducting pole coils are fastened on rotating sleeve (207)
5. The system as claimed in claim 1, wherein warm gas pipe (209) connects each pole coil housings to warm gas main heeder (210)
6. The system as claimed in claim 1, wherein warm gas pipes (211) connects warm gas main header to warm gas sub-header (212), allowing warm gas back to rotary coupling through return gas pipes (213).
7. The system as claimed in claim 6, wherein the warm gas from rotary coupling flows back to stationery cryocooler (101) to complete the cycle.