WATER-HEATING PLANT FOR HEATING PURPOSES AND/OR HOT-WATER SUPPLY, COOLED CONDENSATE RETURN TANK OF PLANT, AND LIQUID-TO-LIQUID HEAT EXCHANGER OF PLANT

FIELD: thermal engineering. SUBSTANCE: plant is connected to heat-load circuit and has heat generator communicating with gas conduit accommodating set of gas-to-liquid plate exchangers assembled of at least initial and final heat exchangers, condensate return tank, and liquid-to-liquid heat exchanger of plant. Heating-medium outlet of liquid-to-liquid heat exchanger of plant communicates with final heat-exchanger inlet. Heating-liquid inlet of liquid-to-liquid heat exchanger of plant communicates with outside water flow source and outlet, with inlet of hot-water system heat exchanger. Outlet of initial heat exchanger communicates with final heat exchanger through flow separator. Plant is provided with its circulating coolant loop of final heat exchanger incorporating liquid-to-liquid apparatus of plant and pump; outlet of final heat exchanger communicates with heating-medium inlet of liquid-to-liquid heat exchanger of plant. Circulating coolant loop of final heat exchanger communicates with heat load circuit; for the purpose heat load outlet has one outlet of its flow separator communicating through controllable valve with inlet of final heat exchanger and other outlet of its flow separator communicates with outlet of final heat exchanger. Cooled condensate return tank of plant is formed by at least two rows of cooled V-shaped sections whose projections on horizontal plane are crossing all sectional areas of gas conduit. Side walls of condensate return tank are cooled structures. Two of them are formed by plates with passages for inflow of cooling liquid and two other ones, by inlet and outlet headers of plates and passages of V-shaped sections. Disposed under side walls is frame that has grooves with condensate drain holes. Liquid-to-liquid heat exchanger of plant has stack of plates with passages for heating and heated media incorporating separating plates and extreme force plates. Stack of plates has intermediate plates such as those of rubber provided with through holes that organize parallel passages. Each separating plate has two groups of holes and each intermediate plate, one group of holes, one group of holes in separating plates being matched with that in intermediate plates and other one, with parallel passages. Parallel passages for heated/heating medium inflow are intercommunicating; to this end outlets of parallel heated/heating medium passages communicate through group of holes in separating and intermediate plates with inlets of next parall