Patent ID: 11940187
Assignee: JIANGSU UNIVERSITY OF SCIENCE AND TECHNOLOGY
Field: Chemical engineering (Chemistry)
Classification: CPC F  B  C  Y | IPC B  C  F

Claim 6:
7. An operating method for the water treatment system of coupling the heat pump with the multi-effect evaporation according to claim 2, comprising:
providing an aqueous solution to be treated; and
opening the first pressure reducing valve (4), the second pressure reducing valve (13), and the first cut-off valve (23),
wherein the aqueous solution to be treated enters the first centrifugal pump (1) for pressurizing, then enters the first-effect evaporator (3) from the solution inlet (b1) after preheating by the pre-heater (2), vapor generated by heating the aqueous solution to be treated in the first-effect evaporator (3) flows into the second-effect evaporator (5) from the top outlet (b5) of the first-effect evaporator (3) through the vapor inlet (c3), the unevaporated water flows out of the outlet (b2) of the first-effect evaporator (3), depressurized by the first pressure reducing valve (4), and then continuously enters the second-effect evaporator (5) for exchanging heat with a vapor flowing in from the first-effect evaporator (3), and a vapor generated by an evaporation is concentrated into a concentrated solution simultaneously and flows out of the outlet (c2) of the second-effect evaporator (5), a condensed water obtained by performing heat-releasing and condensing on a vapor flows into the pre-heater (2) from the outlet (c4) of the second-effect evaporator (5) for heat exchange, a secondary vapor generated in the second-effect evaporator (5) is introduced into the vapor inlet (d1) of the generator (6) from the top outlet (c5) for condensation, and a released heat is used to evaporate a dilute lithium bromide solution in the generator (6);
the dilute lithium bromide solution in the generator (6) simultaneously absorbs both the secondary vapor generated from the second-effect evaporator (5) and a condensation heat of a refrigerant gas compressed by a compressor 14 flowing in from the inlet (d4), a generated vapor enters the condenser (7) for condensation, and a condensed water enters a first evaporator (9) for evaporating into a water vapor after being pressurized by the second centrifugal pump (8), and then the water vapor enters the absorber (10), a lithium bromide solution in the generator (6) is pumped into the solution heat exchanger (11) by the third centrifugal pump (12) for heat-absorption and temperature-rise, then sprayed into the absorber (10) for absorbing a water vapor to obtain a high-temperature lithium bromide solution, a lithium bromide solution in the absorber (10) enters a heat exchange tube of the first-effect evaporator (3) to heat and evaporate a water or solution outside the heat exchange tube, and continuously enters the solution heat exchanger (11) after cooling for exchanging heat with the lithium bromide solution, and enters the generator (6) via the second pressure reducing valve (13) after temperature is reduced for a subsequent circulation;
one path of the refrigerant gas compressed by the compressor (14) in a compressor heat pump circulation enters the generator (6) for heating and condensing to provide heat required for a regeneration of a dilute solution, another path of the refrigerant gas enters the first evaporator (9) to provide heat required for a water evaporation, a condensed refrigerant liquid is converged and then divided into two paths again, one path of the refrigerant liquid enters the second evaporator (16) for evaporation after throttling and depressurizing by the a first throttle valve (18), and another path of the refrigerant liquid enters the third evaporator (17) through the first cut-off valve (23) and the second throttle valve (19) for evaporation, a refrigerant gas flowing out of the second evaporator (16) is regulated by the evaporation pressure regulating valve (20), and then is converged with a refrigerant gas flowing out of the third evaporator (17), and then enters a subsequent circulation after being compressed by the compressor (14);
wherein the third evaporator (17) is an air source evaporator, and during winter the operating method further comprises:
when a surface of the air source evaporator is frosted and requires to be defrosted, opening the second shut-off valve (24), and one part of the refrigerant gas generated by the compressor (14) enters the third evaporator (17) through a pipeline for hot-gas bypass defrosting.