Heat exchanger for condensation in clothes drying and clothes drying system and clothes dryer and drying method thereof

A clothes dryer, comprising a clothes tub, an air outlet, a filter, a drying fan, a heating unit, a heat exchanger and an air inlet, wherein:

• the clothes dryer also comprises a water collection box;
• the air outlet communicates with the heat exchanger;
• the heat exchanger communicates with the water collection box;
• the water collection box communicates with the air inlet;
• the filter is arranged between the air outlet and the heat exchanger;
• the drying fan and the heating unit are arranged between the water collection box and the air inlet;
• the heat exchanger is an external air-cooled type heat exchanger, which comprises two groups of air channels oriented in different directions and not communicating with each other;
• the groups of air channels are respectively a condensing air channel and an external air channel;
• each group of air channels is composed of a plurality of air chambers;
• the air chambers of the two groups of air channels are arranged alternately, and
• a space between each two neighboring air chambers of the condensing air channel is an air chamber of the external air channel;
• a condensate fan is set on one end of the external air channel, and another end is communicated to the outside;
• one end of the condensing air channel is a hot and humid air inlet, and another end of the condensing air channel is a condensed air outlet;
• a mechanism for flushing lint is arranged at one end of the hot and humid air inlet of the condensing air channel of the heat exchanger;
• and
• the mechanism for flushing lint comprises a flushing valve connection communicating with the outside, a flushing passageway communicates with the flushing valve connection and is located within the hot and humid air inlet and annularly around the groups of air channels, and a flushing mouth is located along the inside edge of the flushing passageway, the flushing mouth being configured to flush water towards the air chambers of the condensing air channel.

A clothes drying method, comprising:

• during drying, (i) running hot and humid air through a hot and humid air channel of a residual heat recovery device for preliminarily exchanging heat with a residual recovery air channel, the hot and humid air having been obtained by heat exchange of hot air in a clothes tub with clothes, and (ii) running the hot and humid air through a heat exchanger to condense moisture from the hot and humid air and collecting the moisture inside and a water collection box, whereby dry air is obtained;
• then preheating the dry air in the residual heat recovery air channel by exchanging heat with the hot and humid air channel of the residual heat recovery device;
• and
• then heating a preliminarily preheated dry air via a heating unit to obtain heated dry air, and directing the heated dry air to the clothes tub to exchange heat with the clothes in the clothes tub,
• wherein the method further comprises flushing lint using a mechanism for flushing lint,
• wherein:
• the heat exchanger is an external air-cooled type heat exchanger, which comprises two groups of air channels oriented in different directions and not communicating with each other;
• the groups of air channels are respectively a condensing air channel and an external air channel;
• each group of air channels is composed of a plurality of air chambers;
• the air chambers of the two groups of air channels are arranged alternately, and
• a space between each two neighboring air chambers of the condensing air channel is an air chamber of the external air channel;
• a condensate fan is set on one end of the external air channel, and another end is communicated to outside;
• one end of the condensing air channel is a hot and humid air inlet, and another end of the condensing air channel is a condensed air outlet;
• the mechanism for flushing lint is arranged at one end of the hot and humid air inlet of the condensing air channel of the heat exchanger;
• and
• the mechanism for flushing lint comprises a flushing valve connection communicating with the outside, a flushing passageway communicates with the flushing valve connection and is located within the hot and humid air inlet and annularly around the groups of air channels, and a flushing mouth is located along the inside edge of the flushing passageway, the flushing mouth being configured to flush water towards the air chambers of the condensing air channel.