AN UPDATED METHOD FOR HEATING CALCULATING IN BUILDINGS WITH INTERMITTENT HEATING

An updated method of heating calculation of buildings operated in the conditions of intermitt ent heating is considered. On the basis of the conducted studies, analytical dependences were obtained for determining energy consumption during heating of building enclosing structures, taking into account the infl uence of the order of location of thermal insulation and structural layers, as well as temperature changes during heating of each layer. Formulas for fi nding the change in the temperature of the internal air during the heating of the premises and the internal surface of the enclosing structures are obtained. On the basis of the proposed refi ned methodology, the calculation of the heating of the living room of a country cott age located on the territory of the Samara region was performed.

Factors behind consumers' choices for healthy fruits: a review of pomegranate and its food derivatives

Due to the rising interest in healthy products, superfoods such as pomegranate have begun to spread widely on the international market in recent years. Identification of the consumer choice determinants is a key factor behind the success of innovative products. Nevertheless, to date, there has been no comprehensive analysis of consumers’ preferences for pomegranate. The aim of this study is to understand the characteristics of pomegranate and its derivatives that are most preferred by consumers and to identify the buyers’ profiles by performing a systematic review (SR). The results suggest that there is not equal interest in the literature in all areas of the review. Indeed, most efforts have been made in characterizing the products, whereas consumers’ profiles and their willingness to pay for the various products features have been scarcely investigated. The SR highlights that consumer preference is first correlated with taste and, in particular, with the sweetness (positively) and astringency (negatively) of the product. The red colour and uniform shape of the husk are attractive attributes for consumers, as is the juiciness of the arils. Some innovative methods of product storage, such as intermittent heating (for fruits) and the use of pectin methyl esterase (for arils), guarantee higher consumer acceptability due to the maintenance of product genuineness. Moreover, familiarity with the product seems to be the main driver influencing consumers’ purchase decisions; in addition, people who are more “future oriented” are more willing to pay for pomegranate because of the nutraceutical attributes stressed on the label.

CARTECH 347

CarTech 347 is a niobium+tantalum stabilized austenitic stainless steel. Like Type 321 austenitic stainless steel, it has superior intergranular corrosion resistance as compared to typical 18-8 austenitic stainless steels. Since niobium and tantalum have stronger affinity for carbon than chromium, carbides of those elements tend to precipitate randomly within the grains instead of forming continuous patterns at the grain boundaries. CarTech 347 should be considered for applications requiring intermittent heating between 425 and 900 °C (800 and 1650 °F). This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-1339. Producer or source: Carpenter Technology Corporation.

ALGORITHMS AND SOFTWARE OF BUILDINGS INTERMITTENT THERMAL CONDITIONS OPTIMAL CONTROL

The actual problem of synthesizing the optimal control law for the intermittent heating mode of office buildings is considered, which consists in the programmed reduction of the room temperature during off-hours. The analysis of information sources showed the absence of sufficiently justified methods for solving the problem of optimizing the thermal processes of buildings, which provide comfortable conditions for the functioning of personnel, on the one hand, and save costs for buildings maintenance, on the other hand. The statement of the building thermal state optimal control problem is formulated, which contains a mathematical model of the process, a control goal, constraints on control actions and an integral quadratic quality criterion, including deviations of the room temperature from a given program and heat consumption. The limitation on the control action is taken into account by the method of penalty functions. As a mathematical model of the optimized thermal process, a two-dimensional controlled system of differential equations with constant coefficients is applied. The values of these coefficients are determined on the basis of building similarity criteria, which allows solving the optimization problem in a dimensionless form. The model includes a control action - the supplied heat flux, and a disturbing action - the ambient temperature, changing according to a given harmonious law. The numerical solution of the optimal control problem is implemented by the Chernous'ko method of successive approximations. A description of the user interface is given, as well as examples of the implementation of the thermal state optimal control. The proposed software allows on the stage of designing the heating system to obtain express assessments of various thermal modes of the building, and can also be used as computer support for automated individual heating points. Keywords: intermittent heating mode, optimal control, mathematical model, control quality criterion, control constraints, penalty function, successive approximations, program interface, automated individual heating point.

TEMPERATURE MEASUREMENT OF POLYMERS UNDER INTERMITTENT HEATING THROUGH USE OF THERMOCOUPLE AND ARDUINO® MICROCONTROLLER

The combination of relatively low production costs and a versatility makepolymers one of the most used classes of engineering materials. Thecomplexity of their chemical bounds, however, make the thermomechanicalprocessing of these materials a challenge since thermal flux frommanufacturing might significantly alter their properties. In this paper wasevaluated the use of thermocouple with Arduino® compatible hardware formeasurement and control of an intermittent heating system for processing ofNylon-6 and polycarbonate thermoplastics. A 2² factorial design was createdfor using K-type thermocouple for the two polymers at two different surfacefinishes obtained by sanding with mesh #80 and #600 abrasives. The resultsindicate that the Arduino interface has satisfactory processing capacity formonitoring heating cycles and temperature logging, making it possible toknow how temperature variated and at what level it stabilized for the heatingconditions presented. The difference in material specific heat capacity andthermal conductivity will affect the observed temperature profile. Roughnessmight present a considerable effect on the material heating since it is linkedto the heat exchange area of the process.

DEVELOPMENT OF THE MODE OF MASHING KVASS BASED ON BUCKWHEAT RAW MATERIALS

The preparation of soft drinks is an actively developing branch of the food industry in the Republic of Kazakhstan. To meet the interests of all producers, the enterprises annually produce a large number of non-alcoholic products. To maintain a healthy competition of the enterprise for preparation of soft drinks, create and apply the technology not previously known and expand the assortment of products annually. One of the most popular segments of this market is kvass. This is mainly due to the fact that all over the world there is an increasing demand for products made from natural raw materials, prepared without the addition of any synthetic additives and ingredients. In recent years, there has been an active increase in the consumption of kvass and its replacement with a large share of the market of carbonated soft drinks. The domestic kvass market is very rich and diverse, but there is a problem with the lack of functional drinks for certain groups of citizens. Creating a wide range of functional food products, including beverages, is becoming feasible. At the same time, in the production of kvass, it is important to use non-traditional raw materials, including buckwheat, the introduction of which in the kvass technology allows you to significantly expand the product range. A distinctive feature of buckwheat, which determines the prospects for use in the production of kvass, is its chemical composition. It is rich in vitamins and is considered an important source of antioxidants due to its high concentration of flavonoids. Buckwheat contains rutin, quercetin, folic acid, quercitrin, hyperoside. Thus, the replacement of barley malt with buckwheat contributes to an increase in the proportion of natural flavonoids in the drink, and therefore in the human diet. In this article, studies have been conducted to study the effect of the dose of buckwheat, buckwheat flakes, buckwheat malt and methods of their pretreatment on the effectiveness of the mashing process, when using it as an unsalted material. Buckwheat grains, buckwheat flakes and buckwheat malt were used in the work. Studies of mashing modes and indicators that determine their effectiveness have shown that the use of buckwheat malt in the backfill is more optimal than buckwheat grain. Studies have shown that the most economical and promising when using extruded buckwheat flakes as an unsalted material is the use of a single-boil mashing mode. However, the use of such raw materials is possible in concentrations not exceeding 30% of the backfill. If you need to increase the proportion of buckwheat in the backfill, you should use buckwheat malt. In this case, it is necessary to apply a mashing mode with intermittent heating, which is likely to compensate for the cost of producing malt from buckwheat grain.

Energy-saving potential of intermittent heating system: Influence of composite phase change wall and optimization strategy

In the Yangtze River zone of China, the heating operation in buildings is mainly part-time and part-space, which could affect the indoor thermal comfort while making the thermal process of building envelope different. This paper proposed to integrate phase change material (PCM) to building walls to increase the indoor thermal comfort and attenuate the temperature fluctuations during intermittent heating. The aim of this study is to investigate the influence of this kind of composite phase change wall (composite-PCW) on the indoor thermal environment and energy consumption of intermittent heating, and further develop an optimization strategy of intermittent heating operation by using EnergyPlus simulation. Results show that the indoor air temperature of the building with the composite-PCW was 2–3°C higher than the building with the reference wall (normal foamed concrete wall) during the heating-off process. Moreover, the indoor air temperature was higher than 18°C and the mean radiation temperature was above 20°C in the first 1 h after stopping heating. Under the optimized operation condition of turning off the heating device 1 h in advance, the heat release process of the composite-PCW to the indoor environment could maintain the indoor thermal environment within the comfortable range effectively. The composite-PCW could decrease 4.74% of the yearly heating energy consumption compared with the reference wall. The optimization described can provide useful information and guidance for the energy saving of intermittently heated buildings.