Recovery system and method for recovery of thermal energy from waste water

A recovery system for the recovery of thermal energy from waste water from a building, which recovery system comprises:

• a collector tank to store waste water that freely circulates in the collector tank, wherein a collector tank pump installed on a buffer tank pipeline and a buffer tank pump installed on a collector tank pipeline pumps the waste water between the collector tank and a buffer tank:
• a supply pipeline system for supplying waste water to the collector tank;
• a preparatory unit including a mechanical separation unit protecting a cutting pump, wherein the cutting pump disintegrates coarse particles and pump waste water from the preparatory unit to the collector tank via the supply pipeline system;
• a heat pump;
• a heat exchanger device arranged to be lowered into the collector tank and which is in contact with said waste water;
• and
• a heat transfer fluid pipeline system arranged between the heat pump and the heat exchanger device, wherein,
• the heat pump is configured to absorb thermal energy from a non-freeze liquid circulating through the heat pump, which the non-freeze liquid can be used as a heat transfer liquid, and the heat pump is configured to transfer thermal energy to water flowing through the heat pump, wherein,
• that non-freeze liquid can circulate in said heat transfer fluid pipeline system, wherein the heat exchanger device is configured such that the non-freeze liquid is conveyed through the heat exchanger device, wherein the non-freeze liquid can absorb thermal energy from waste water the collector tank, and wherein,
• the heat exchanger device comprises one or more sets of heat exchanger elements, in order to be lowered into the wastewater of the collector tank, each heat exchanger element comprising at least two substantially parallel plates of a self-supporting polymeric material, wherein the at least two substantially parallel plates form an internal flow passage therebetween for the non-freeze liquid that extends throughout substantially the entire surface the two parallel plates between a non-freeze liquid inlet disposed at one end of the heat exchanger element and an outlet for non-freeze liquid provided at the other end of the heat exchanger element.