Design of Monitoring and Controlling System for Smart Home

An intelligent lifestyle has become a hotspot for researchers and industries nowadays. The smart home monitoring and controlling system with the Arduino as the main controller is designed in this paper, combined with sensors, Wi-Fi, and cloud technologies. Various sensors collect household environmental information, such as indoor temperature and humidity, soil moisture, combustible gas concentration, and light intensity. The main controller processes the collected signals and automatically operates the devices, including a refrigeration equipment, water pump, buzzer, fan, stepping motor. The data can also be transmitted to the cloud platform through Wi-Fi for processing, and the home environment information and device can be remotely monitored and controlled by the cloud platform or smartphone APP.

Heat recovery in the refrigeration equipment of dining cars

The paper investigates the major parameters of the existing refrigeration equipment of dining cars, as well as analyzes the latest trends in the development of refrigeration equipment, taking into account the changing requirements of legislation and environmental standards. Besides, it compares several systems with different refrigerants. Finally, our study introduces the possibilities of exploiting a transcritical system with heat recovery.

Assessment on Performance advancement utilizing nanofluid as additional fluid in a Refrigeration System

The performance of the refrigeration machine needs to be increased, which usually may be carried out by changing the unit or the properties of primary and additional working fluids. Currently, nanofluids or hybrid nanofluids possess obtained curiosity in various engineering areas scheduled to it has the superb thermophysical properties, which will be quickly applied in refrigeration equipment by various functions for overall performance improvement. This paper assesses and then summarizes the latest research carried out on the consumption of nanofluids in the refrigeration machine as the supplementary liquid is mentioned. At last, the difficulties and possibilities for upcoming study are determined, which will be beneficial for the beginners and then concerns in this discipline.

Ecoenergetic Comparison of HVAC Systems in Data Centers

The topic of sustainability is of high importance today. Global efforts such as the Montreal Protocol (1987) and the Kigali Amendment (2016) are examples of joint work by countries to reduce environmental impacts and improve the level of the ozone layer, the choice of refrigerants and air conditioning systems, which is essential for this purpose. But what indicators are to be used to measure something so necessary? In this article, the types of air conditioning and GWP (Global Warming Potential) levels of equipment in the project phase were discussed, the issue of TEWI (Total Equivalent Warming Impact) that measures the direct and indirect environmental impacts of refrigeration equipment and air conditioning and a new methodology for the indicator was developed, the TEWI DC (DC is the direct application for Data Center), and using the formulas of this new adapted indicator it was demonstrated that the TEWI DC for Chicago (USA) was 2,784,102,640 kg CO2/10 years and Curitiba (Brazil) is 1,252,409,640 kg CO2/10 years. This difference in value corresponds to 222.30% higher annual emissions in Chicago than in Curitiba, showing that it is much more advantageous to install a Data Center in Curitiba than in Chicago in terms of environmental impact. The TEWI indicator provides a more holistic view, helping to combine energy and emissions into the same indicator.

Efficiency of "lean management" application in business processes management of refrigeration equipment supply chain during the COVID crisis

The article reveals the main trends in the functioning of global supply chains in the context of the COVID-19 pandemic and their impact on the activities of Ukrainian enterprises are identified. It is noted that the closure of borders between countries and the introduction of self-isolation regime caused a significant reduction in production capacity and the volume of international trade. Global supply chains have become very vulnerable and necessitate their revision and the search for alternative ways to deliver goods to end users. Since Ukraine is a country with an open market economy, this article summarizes the main challenges for import-dependent supply chains and makes proposals on ways to overcome them. The expediency of applying the concept of Lean-management in business processes management of refrigeration supply chains during a pandemic as a means of overcoming crisis situations and ensuring sustainable development are proved. The dynamics and structure analysis of the company LLC "Holod Engineering" income and expenses allowed to establish a tendency to reduce the profitability of the company's business and capital turnover, as well as increase the share of logistics costs in the production costs. The greatest impact on the growth of logistics costs have the inventory costs due to the processes of storage and orders completion and delivery delays, which lead to customer dissatisfaction and complaints. Methodical approaches to estimating the level of processes coordination in the supply chains of refrigeration equipment, calculation of supply lots optimal parameters, levels of raw materials and components stocks, production and storage capacity rationalization of the enterprise are substantiated. With the help of Shewhart's control charts, the coordination of business processes in the equipment supply chains were assessed and the sources of potential losses were identified. The technological and logistics processes optimization in terms of their cost, duration and quality of results takes into account not only individual processes of enterprises, but also interprocess connections between supply chain links. It is proposed to implement a number of organizational measures using the concept of lean management, which involves market integration, production process, procurement and sales in order to provide a high level of customer service. The efficiency of the proposed organizational changes and their impact on business profitability, inventory turnover, the amount of logistics costs and the quality of customer service are determined.

ANALYSIS OF THE CURRENT SITUATION WITH RECYCLING OF ELECTRICAL AND ELECTRONIC EQUIPMENT WASTE IN VIETNAM

Today, in world practice, a rapid increase in the rate of generation of household and industrial waste is noticeable, and Vietnam, as a developing country, this problem is especially tangible. With the development of industry and technology, one of the most problematic industries in terms of waste generation is the electrical and electronic equipment industry. The products of this industry are tightly integrated into all other sectors of human life, whether it is production (refrigeration equipment, machine tools, computers, monitors, communications, etc.) or everyday life (household appliances, mobile phones, game consoles, smart appliances, etc.). This article provides an analysis of the current situation with the recycling of waste electrical and electronic equipment in Vietnam, and provides recommendations for solving this problem.

The prospect of using ozone-safe refrigerants with low global warming potential in scroll compressors. Part 1

The Montreal Protocol and the Kigali Amendment have determined the need and deadlines of the replacement of hydro fluorinated refrigerants. Substances of natural origin with a low global warming potential are becoming an alternative to hydrofluorocarbons that are being withdrawn from circulation. Such an alternative corrects the vector of development of refrigeration equipment and entails the need to adapt or create new models of equipment taking into account the excellent properties of new refrigerants. However, the consumer’s choice is still based on the efficiency, cost and reliability of the equipment. Having studied the possibility of using new refrigerants, in the fields of using a scroll compressor, from the point of view of the operational properties of substances, we also noted some aspects of the influence of their thermodynamic and thermophysical properties on the working processes and design of compressor elements. Thus, we present a comparative analysis of the practical application and further prospects for the using of refrigerants in a scroll compressor, highlighting the current directions of studying this issue.

Simulation and Analyses of a Novel Air-conditioning Solution for Improving Energy Saving in a Data Room

In view of the feature of long airflow path, high wind resistance, and large area of refrigeration equipment in traditional data room, a new type of under-floor modular air conditioner and its corresponding new air conditioning solution for data room is proposed in this paper. The mathematical and physical model of the new solution for data room is established through a computational fluid simulation software and compared with two mainstream air conditioning solutions. Meanwhile, the impact of these three different air conditioning solutions on the temperature field, airflow field and energy consumption are analysed. The results show that the new type air conditioning solution for data room not only can be used to improve the distribution of temperature and airflow in the data room, but also can greatly reduce the energy consumption of the system.