HEAT EXCHANGER FOR VEHICLE AIR CONDITIONING SYSTEM, VEHICLE AIR CONDITIONING SYSTEM, AND VEHICLE

A heat exchanger for a vehicular air conditioning system, including a heat exchanger body (20), a water storage tank (200) and a condensate water circulating device. The heat exchanger body (20) is provided with an air-inlet side (21) and an air-outlet side (22), wherein the air-inlet side (21) is configured to enable an external air flow to enter the heat exchanger body (20), so that the air flow conducts heat exchange with a refrigerant in the heat exchanger body (20), the air-outlet side (22) is configured to exhaust the air flow completing heat exchange with the refrigerant, the water storage tank (200) is arranged below the heat exchanger body (20) and is configured to store condensate water formed on the heat exchanger body (20), and the condensate water circulating device is configured to transport cold water in the water storage tank (200) to the air-inlet side (21) of the heat exchanger body (20) for heat exchange with the heat exchanger body (20).