Показана целесообразность форсирования подводимой тепловой нагрузки на генератор абсорбционного холодильного агрегата в период пуска – снижение энергозатрат при эксплуатации может составить от 25 до 35%. Предложен bи обоснован новый способ управления абсорбционного холодильного агрегата с установкой теплоизоляционного кожуха на всем подъемном участке дефлегматора. Показано, что при учете особенностей эксплуатации абсорбционного холодильного агрегата в широком диапазоне температур воздуха окружающей среды одним из эффективных и малобюджетных методов повышения энергетической эффективности АХП является технология снижения потерь при транспортировке аммиака в зону производства искусственного холода (испаритель).
Ключевые слова: Энергетическая эффективность; Абсорбционный холодильный агрегат; Влияние форсажа тепловой нагрузки генератора; Влияние температуры воздуха окружающей среды; Транспорт аммиака в зону испарения
Показано доцільність форсування теплового навантаження на генератор абсорбційного холодильного агрегату в період пуску - зниження енерговитрат при експлуатації може скласти від 25 до 35%. Запропоновано та обґрунтовано новий спосіб управління абсорбційного холодильного агрегату з установкою теплоізоляційного кожуха на всій під’ємній ділянці дефлегматора. Показано, що при обліку особливостей експлуатації абсорбційного холодильного агрегату в широкому діапазоні температур повітря навколишнього середовища, одним з
ефективних та малобюджетних методів підвищення енергетичної ефективності АХП є технологія зниження втрат при транспортуванні аміаку в зону виробництва штучного холоду (випарник).
Ключові слова: Енергетична ефективність; Абсорбційний холодильний агрегат; Вплив форсажу теплового навантаження генератора; Вплив температури повітря навколишнього середовища; Транспорт аміаку в зону
випаровування.
Absorption refrigerators (AR) with absorption cooling units (ACU) have an increased energy consumption during operation due to the thermodynamic imperfection of the absorption refrigeration cycle, the presence of low-intensity diffusion Холодильна техніка та технологія, 53 (3),2017
processes of mass transfer in the evaporator and absorber and the losses associated with evaporation and Subsequent transportation of ammonia from the generator unit to the condenser and then the evaporator. The greatest effect in energy saving during the operation of ACU with minimal changes in design can be achieved by improving the operation modes of generating units. The main direction of modern research of AR is aimed at qualitative obtaining of experimental data. The objects of experimental research were modernized models of household absorption single-chamber refrigerators "Kyiv-
410" and "Kristall-408". The modernization consisted in the installation of an additional heat-insulating casing on the generating set in such a way that the entire lifting section of the reflux condenser was closed. The parameters of the heatinsulating casing were chosen taking into account the known recommendations, in particular, the thickness of the thermal insulation made of glass fiber was 4 mm. To estimate the rate of displacement of the inert gas during the starting period, the amount of generated steam was calculated by calculation. For the analysis, the results of known studies and own experience were used. It was shown the expediency of forcing the heat load on the generator - the reduction of energy costs during the start-up period can be from 25 to 35%. Taking into account the calculation results, the original three-position control methods of AXA with the thermal load input to the generator "110 - 70 - 0" and "130 - 70 - 0" were proposed. It is
shown that the method of controlling the AR with a constant two-stage supply of heat load and controlling the flow temperature at the outlet of the reflux condenser allows to reduce energy consumption by up to 20 %, in comparison with traditional position control. Despite the constant in time supply of heat load to the generator, the advantage was achieved due to: A) maintaining the elements of the generating set in the "warmed up" state, which makes it possible to minimize the transition time to the mode with the rated refrigerating capacity of the evaporator; B) maintaining the minimum refrigerating
capacity of the evaporator in the "waiting" mode. The energy-saving effect of the new control method is largely related to the installation of the heat-insulating casing on the dephlegmator. This allows not only to use the minimum refrigerating capacity of the evaporator (at Q = 40 W), but also to switch to a lower level of rated thermal load (Q = 70 W) compared to the serial version (Q = 110 W). The duration of the working period for absorption refrigerators is related to the inertia of the startup processes, when all the energy input is spent only on the heating of the elements of the generator assembly. In
this regard, measures aimed at maintaining energy-efficient operation modes of the generating set, despite the additional energy costs, provide advantages in energy saving. It is possible to achieve a sufficiently significant increase in the efficiency of the ACU operation, taking into account the peculiarities of their operation over a wide range of ambient air temperatures. One of the effective and low-budget methods for increasing the energy efficiency of ACU is the technology to reduce losses when transporting ammonia to the artificial cold zone (evaporator). A key role in this process is performed by the AR reflux condenser, which purifies ammonia vapor by removing the heat of a phase transition into the environment in the temperature range from 10 to 32°C. To reduce losses during the transportation of ammonia through the AR dephlegmator, it is necessary to install a thermal insulation that would efficiently purify ammonia vapor (at high ambient
temperatures) within the working temperature range and promote its minimum ondensation of ammonia (at low ambient temperatures). An original design of the mobile heat insulation of the dephlegmator transport zone is proposed, which regulates the air supply to the dephlegmator by moving the bellows walls filled with a low-boiling liquid.
Keywords: energy efficiency; absorption cooling unit; influence of the afterburning of the thermal load of the generator, effect of ambient air temperature, transport of ammonia to the evaporation zone
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