Php putenv functions cannot be used in Chinese

If you know laravel, you can take a look at the above section. if you don't know about it, go straight to the split line ;. for any item in env, use MAIL_DRIVER as an example to change it to "my". use the env function to get the value normally. change it to "I" and use the env function to get the value normally; {code ...} other... if you know laravel, you can take a look at the above section. if you don't know about it, go straight to the split line below;

Any item in. env takes MAIL_DRIVER as an example.
Change to "my" and use the env function to get the value normally;
Changed to "I" and the env function won't be available;

MAIL_DRIVER = my var_dump (env (MAIL_DRIVER ''); // NULLMAIL_DRIVER = my var_dump (env (MAIL_DRIVER''); // My

Other Chinese characters, such as "good", will also encounter this situation;
I have to say that laravel is profound and profound. I have studied the env function source code;
The final problem is;
----------------------------------------------- Understand and do not understand the split line of the laravel framework ------------------------------------------------

Putenv ("PROJECT_NAME = my"); phpinfo ();

In phpinfo, Environment can be searched for PROJECT_NAME.

Putenv ("PROJECT_NAME = Me"); phpinfo ();

In phpinfo, Environment cannot find PROJECT_NAME.

Ask your friends. why? How can I set Chinese values without barriers?