A stator iron core for an electric machine comprising a medium conveying and heat exchange device, the stator iron core being provided with a cooling passage running through the stator iron core radially, wherein the medium conveying and heat exchange device comprises a plurality of vortex flow separators configured to generate a heat exchange medium in the stator iron core; and wherein each of the vortex flow separators comprises a jet pipe and a vortex flow separation pipe, wherein the vortex flow separation pipe comprises a vortex flow chamber, and a cold end pipe section and a hot end pipe section located at two ends of the vortex flow chamber, respectively; the jet pipe is in communication with the vortex flow chamber, and compressed airflow is allowed to flow through the jet pipe to form spiral airflow, and the spiral airflow is allowed to flow into the vortex flow chamber in a tangential direction of the vortex flow chamber; a cross-sectional area of the cold end pipe section is smaller than a cross-sectional area of the vortex flow chamber, and a cross-sectional area of the hot end pipe section is equal to or greater than the cross-sectional area of the vortex flow chamber; and a valve having a valve port is arranged inside the hot end pipe section, the valve has a cone-shaped surface facing the cold end pipe section, and after the spiral airflow is introduced into the vortex flow separation pipe, external airflow of the spiral airflow is allowed to flow toward the valve port, be gradually heated to become hot airflow, and then flow out through the valve port; central airflow of the spiral airflow is allowed to pass by the cone-shaped surface of the valve and flow back, be cooled to become cold airflow, and then flow out from the cold end pipe section; the cold airflow and/or the hot airflow are heat exchange mediums generated in the stator iron core, and the cold airflow generated by the plurality of vortex flow separators is conveyed into the cooling passage as cooling airflow; and the medium conveying and heat exchange device further comprises an air collection tank in which the compressed airflow is converged, the air collection tank is provided with a plurality of branch pipes, each of the branch pipes is provided with at least two of the plurality of the vortex flow separators, and each branch pipe is configured to supply the compressed airflow to the jet pipes of the corresponding two vortex flow separators. a cross-sectional area of the cold end pipe section is smaller than a cross-sectional area of the vortex flow chamber, and a cross-sectional area of the hot end pipe section is equal to or greater than the cross-sectional area of the vortex flow chamber; and a valve having a valve port is arranged inside the hot end pipe section, the valve has a cone-shaped surface facing the cold end pipe section, and after the spiral airflow is introduced into the vortex flow separation pipe, external airflow of the spiral airflow is allowed to flow toward the valve port, be gradually heated to become hot airflow, and then flow out through the valve port; central airflow of the spiral airflow is allowed to pass by the cone-shaped surface of the valve and flow back, be cooled to become cold airflow, and then flow out from the cold end pipe section; the cold airflow and/or the hot airflow are heat exchange mediums generated in the stator iron core, and the cold airflow generated by the plurality of vortex flow separators is conveyed into the cooling passage as cooling airflow; and the medium conveying and heat exchange device further comprises an air collection tank in which the compressed airflow is converged, the air collection tank is provided with a plurality of branch pipes, each of the branch pipes is provided with at least two of the plurality of the vortex flow separators, and each branch pipe is configured to supply the compressed airflow to the jet pipes of the corresponding two vortex flow separators.