Transforming a home refrigerator into a BOD prototype for statice vernalization

Vernalization, natural or artificial, is a physiological requirement of some plants to meet the need for low temperatures for its complete development to occur. The objective of this article is to describe a protocol of transforming a domestic refrigerator into a BOD (Biochemical Oxygen Demand) prototype aimed at vernalizing propagating materials statice crop. The first step is to install a temperature controller to maintain a constant temperature inside the refrigerator (10 °C). Thinking of seedling vernalization, it is still necessary to install a system of lights inside the refrigerator. The control of the time that the lights remain on inside the prototype is carried out by installing a Timer adjusted so that the lights remained on, uninterruptedly, for 10 hours. To test the effective ness of the prototype, an on-farm experiment was carried out with the statice (Limonium sinuatum L.) crop at 5 locations in Rio Grande do Sul, Brazil. The seedlings were vernalized at an internal temperature of 10 °C and photoperiod of 10 hours for 3 weeks. The duration of this experiment was 8 months and at the end of this observed that statice plants were correctly vernalized because the plants emitted flower stems and showed satisfactory development throughout the growing cycle. Therefore, that the adaptation of a domestic refrigerator as a BOD economically viable and easy mounting prototype is possible. Being an excellent alternative to small producers.

Energy Analysis of HFC-152a, HFO-1234yf and HFC/HFO Mixtures as a Direct Substitute to HFC-134a in a Domestic Refrigerator

The Kyoto protocol emphasized the need of replacement of HFC refrigerant due to their high GWP values that causes pollution in the environment. So in this paper the refrigerants R1234yf, R152a and HFOs/HFCs mixtures of R134a/R152a/R1234yf such as ARM42 (in the ratio of 8.5/14 /77.5 by mass), ARM42a (in the ratio of 7/11/82 by mass) with a view of replacement of the refrigerant HFC-134a in a domestic refrigerator were analyzed theoretically. Volumetric cooling capacity, compressor discharge temperature, coefficient of performance, compressor energy consumption and refrigeration capacity are the main parameters to estimate the performance of the refrigerator. The results are revealed that HFC-152a had gave a superior performance as compared to HFC-134a in terms of COP and equal cooling and volumetric cooling capacities. However, the refrigerant HFC-152a was flammable and runs with high compressor outlet temperature which may restrict its usage. The HFO refrigerant R1234yf showed an almost equal volumetric cooling capacity, compressor energy consumption, refrigerating effect and COP when compared with HFC-134a. Among the refrigerants ARM42 and ARM42a, the refrigerant ARM42a was selected as a good alternative for HFC-134a because the Volumetric cooling capacity and COP of ARM42a were almost equal to HFC-134a. Therefore ARM42a had better choice of direct substitute to HFC-134a in a domestic refrigerator when the corresponding safety requirements are adopted. So on overall comparison of every property of refrigerants we can conclude that R1234yf can be treated as best alternative to HFC-134a in a domestic refrigerator.

Performance Scrutiny of Domestic Refrigerator Using a Stepped Mini Orifice as A Capillary Tube Extension with Sio2 Nano Lubricant And R-290 Refrigerant

A stepped short tube orifice has been proposed as a replacement for the expansion mechanism in a residential refrigerator that runs on R-290. The present work is primarily concerned with the impacts of stepped short tube orifices on system characteristics such as net refrigeration effect, compressor effort, pull down time, and coefficient of performance. A stepped short tube orifice is made up of two short tube orifices linked serially and having varying sizes. It is used as an extension to the capillary tube in the refrigeration system. A stepped short tube orifice is built and fitted to a home refrigerator in this experiment. The experiments must be done on a home refrigerator equipped with a stepped short tube orifice, R-290 refrigerant, and a 0.5% weight SiO2 nanoparticle. Following the completion of all trials, the effects of the stepwise short tube orifice on a residential refrigerator were studied using comparison charts. The results indicate that the performance of the home refrigerator with stepped short tube orifice and SiO2 nano particle inclusion was much better than the domestic refrigerator without stepped short tube orifice.

Experimentally Validated Model of a Domestic Refrigerator with an Immersed Condenser Coil for Water Heating

This study presents a coupled model to simulate the heat transfer process between the helical condenser coil and the water inside the tank. This coupled model was developed using ANSYS Fluent Computational Fluid Dynamics (CFD). The heat flux of the condenser coils is obtained from our experimental investigation and delivered as initial boundary conditions to the tank model. The results obtained are considered essential and are, in turn, capable of assessing the performance of the modified domestic refrigerator for the production of hot water. According to this model, the results confirmed that the coefficient of heat transfer and the performance of the system decreased with an increase in the heating time. The natural heat transfer coefficient Uc falls from 727.26[Formula: see text]W [Formula: see text] m[Formula: see text] [Formula: see text] K[Formula: see text] to 68.64[Formula: see text]W [Formula: see text] m[Formula: see text] [Formula: see text] K[Formula: see text] during the total heating cycle, and the water temperature rises from 20∘C to 50.73∘C. In addition, the impact of water temperature on the evaporating region was used in this analysis. Therefore, the temperature of the evaporator is unaffected by the development of hot water. As a result, these outcomes will be used for the development of the domestic refrigerator with immersed condenser coil.