Control system for a natural gas distribution network, comprising: - a processing unit suited to communicate, through corresponding signals, with one or more control devices operatively connected to said distribution network; - a rechargeable battery which supplies power to said processing unit; - a power supply device suited to recharge said rechargeable battery; said power supply device comprising: - a thermoelectric generator connected to said rechargeable battery; - a first heat exchanger and a second heat exchanger (14; 40; 50) respectively in contact with two sides of said thermoelectric generator opposing each other; - a vortex tube configured to receive a portion of natural gas from said distribution network and to divide said portion into a part which is colder than said portion of natural gas flowing into said vortex tube, and a part which is warmer than said portion of natural gas flowing into said vortex tube; - a first conveyance duct suited to convey said colder part into said first heat exchanger; - a second conveyance duct suited to convey said warmer part into said second heat exchanger (14; 40; 50), characterized in that each heat exchanger (13, 14; 40; 50) comprises a corresponding chamber provided with an inlet mouth and an outlet mouth with a plurality of segments interposed therebetween, said segments defining a winding path for said natural gas from the point where it flows into said chamber through said inlet mouth to the point where it flows out of the same through said outlet mouth, said segments being in contact with said thermoelectric generator. - a processing unit suited to communicate, through corresponding signals, with one or more control devices operatively connected to said distribution network; - a rechargeable battery which supplies power to said processing unit; - a power supply device suited to recharge said rechargeable battery; said power supply device comprising: - a thermoelectric generator connected to said rechargeable battery; - a first heat exchanger and a second heat exchanger (14; 40; 50) respectively in contact with two sides of said thermoelectric generator opposing each other; - a vortex tube configured to receive a portion of natural gas from said distribution network and to divide said portion into a part which is colder than said portion of natural gas flowing into said vortex tube, and a part which is warmer than said portion of natural gas flowing into said vortex tube; - a first conveyance duct suited to convey said colder part into said first heat exchanger; - a second conveyance duct suited to convey said warmer part into said second heat exchanger (14; 40; 50), - a thermoelectric generator connected to said rechargeable battery; - a first heat exchanger and a second heat exchanger (14; 40; 50) respectively in contact with two sides of said thermoelectric generator opposing each other; - a vortex tube configured to receive a portion of natural gas from said distribution network and to divide said portion into a part which is colder than said portion of natural gas flowing into said vortex tube, and a part which is warmer than said portion of natural gas flowing into said vortex tube; - a first conveyance duct suited to convey said colder part into said first heat exchanger; - a second conveyance duct suited to convey said warmer part into said second heat exchanger (14; 40; 50), characterized in that each heat exchanger (13, 14; 40; 50) comprises a corresponding chamber provided with an inlet mouth and an outlet mouth with a plurality of segments interposed therebetween, said segments defining a winding path for said natural gas from the point where it flows into said chamber through said inlet mouth to the point where it flows out of the same through said outlet mouth, said segments being in contact with said thermoelectric generator.