Comparison Study of Thermal Energy Consumption in Distributed Heating at Xi'an Siyuan University

2021 ◽  
Vol 09 (06) ◽  
pp. 303-309
Author(s):  
青华 马
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Comparison Study ◽  
Distributed Heating

scholarly journals Determinants of Electrical and Thermal Energy Consumption in Hospitals According to Climate Zones in Poland

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7585
Author(s):  
Małgorzata Cygańska ◽  
Magdalena Kludacz-Alessandri
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Health Sector ◽  
Integrated Approach ◽  
Climatic Zone ◽  
Energy Costs ◽  
Work Intensity ◽  
Climate Zones ◽  
Climate Zone ◽  
Hospital Size

Energy use in hospitals is higher than in other public buildings, so improving energy efficiency in healthcare buildings is a significant challenge in this sector of engineering. For this, it is necessary to know the various determinants of energy consumption. Until now, the main factor affecting energy consumption in healthcare facilities studied in the literature was hospital capacity. However, the commonly used variables connected with hospital size and the number of beds do not take into account the medical activities carried out in these buildings. Assuming that energy consumption in hospitals is multiple and shaped by many factors that overlap, not only on an individual level but also on a higher scale level, this study devises a more integrated approach to its determinants. This study aims to investigate the determinants of electrical energy costs (EEC) and thermal energy costs (TEC) in Polish hospitals with regard to factors related to their size, work intensity and climate zones. The analysis was carried out using financial and resource data from all Polish hospitals for the years 2010–2019. The study used a multivariate backward stepwise regression analysis. In order to use climate as a moderating variable, a sample of Polish hospitals from 16 Polish NUTS 2 was divided into four climate zones. This article provides new empirical evidence on the determinants of electricity consumption in Polish hospitals related to their size and medical activity, taking into account climate zone as a moderating variable. The results of the analysis show that both electricity and heat consumption in hospitals are positively related to the number of doctors, beds and the number of medical operations performed. As expected, larger hospitals seem to use more energy. Moreover, there is regional heterogeneity in energy consumption in hospitals related to the climatic zone in which they operate. The conducted analysis shows that Polish hospitals located in the warmest climatic zone are characterized by higher energy consumption than hospitals in the coldest zone. It especially regards EEC in surgery hospitals. The warmer the climate zones, the higher intensity in terms of the number of surgeries, the higher EEC. In terms of nonsurgical hospitals, the influence of climate zone on EEC was not observed. Knowing the factors influencing energy consumption in hospitals can facilitate the correct adoption of an energy-saving strategy in the health sector, which is a reasonable response to climate change and supports a healthy and sustainable future.

scholarly journals Research on the Defrosting System of Refrigerated Containers Combining Air and Electro-Thermal Energy and the Controlling Strategy

2021 ◽  
Vol 248 ◽  
pp. 02058
Author(s):  
Kaitai Hua
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Pressure Change ◽  
High Energy ◽  
Structural Features ◽  
Low Energy ◽  
Wind Pressure ◽  
Long Duration ◽  
Low Energy Consumption ◽  
High Energy Consumption

Considering the problems such as long duration of defrosting, low working reliability and high energy consumption of refrigerated containers, this paper put forward a new defrosting method combining air and electro-thermal energy, and designed a new defrosting structure system based on the structural features of refrigeration modules of refrigerated containers. The two-variable method of wind pressure change and temperature difference change on both sides of the evaporator was used to detect frosting, and the specific controlling strategy supporting the new defrosting system was provided to realize the effect of intelligent defrosting. It can provide references for fast defrosting, intelligent defrosting and low energy consumption defrosting of refrigerated containers.

scholarly journals Thermal performance characterisation of a reverse-flow energy recovery ventilator for a residential building application

2019 ◽  
Vol 111 ◽  
pp. 01010
Author(s):  
David Hunt ◽  
Naoise Mac Suibhne ◽  
Laurentiu Dimache ◽  
David McHugh ◽  
John Lohan
Keyword(s):  
Control System ◽  
Energy Consumption ◽  
Thermal Performance ◽  
Thermal Energy ◽  
Carbon Emissions ◽  
Energy Recovery ◽  
Reverse Flow ◽  
Recovery Efficiency ◽  
Indoor Climate ◽  
Climate Control

The European Union’s 2020 and 2030 sustainable energy policies seek significant reductions in both energy consumption and carbon emissions. These policies demand a greater use of energy efficient technologies and a transition away from fossil fuels. This paper studies one such technology, an indoor climate control system with a reverse-flow enthalpy recovery ventilator, capable of recovering both sensible and latent heat. The thermal performance characteristics are established using an experimental facility and calculation methods defined by European Standard EN 13141-7:2010. This involves measurement of temperature, humidity, pressure and volumetric air flow rates over a range of operating conditions. Total thermal energy recovery rates ranged from 0.63 kW to 2.2 kW, with energy recovery efficiency of 72.8 % to 88.6 %. The recovery efficiency ratio, which reflects the capacity of the indoor climate control system to recover thermal energy relative to its power consumption ranged between 6.87 to 19.97. Due to the unique reverse-flow defrost function, the system demonstrates operation down to -7 °C without frost formation. These results highlight the potential that this system can make towards the EU goals of reducing energy consumption, operating costs and carbon emissions associated with indoor climate control.

Energy consumption minimization for a solar lime calciner operating in a concentrated solar power plant for thermal energy storage

2020 ◽  
Vol 156 ◽  
pp. 1019-1027 ◽  
Author(s):  
Pilar Lisbona ◽  
Manuel Bailera ◽  
Thomas Hills ◽  
Mark Sceats ◽  
Luis I. Díez ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Storage ◽  
Power Plant ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Power ◽  
Solar Power Plant ◽  
Concentrated Solar Power

Thermal Performance of Electrochromic Smart Window with Nanocomposite Structure under Different Climates in Iran

2019 ◽  
Vol 11 (2) ◽  
pp. 154-164 ◽  
Author(s):  
Siamak Hoseinzadeh
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Average Energy ◽  
Climatic Conditions ◽  
Smart Window ◽  
Nanocomposite Layer ◽  
Energy Plus ◽  
Average Energy Consumption ◽  
Bandar Abbas ◽  
Different Climates

Objective: This study investigated the optimization of thermal energy consumption using electrochromic components with a new nanocomposite layer (WO3+Ag) in a larger size (window) for a room with an educational application for five cities with different climatic conditions in Iran (Yazd, Tehran, Bandar Abbas, Tabriz, and Sari). Materials & Methods: For this simulation platform, the software was implemented in Energy Plus. This feasibility study was modeled by DesignBuilder software which reported reduced thermal energy consumption across all climates in Iran (hot and dry, warm and semi-humid, warm and wet, moderate and dry, and mild and humid.). Four strategies were considered for better comparison. The first strategy used for common double-glazed windows, while the second to fourth strategies involved the use of the electrochromic window in three different modes; bleached mode (Off), colored mode (On), and switchable mode (controlled below comfort conditions). Results: The third and fourth strategies indicated a reduction in thermal energy consumption in different climates from 25 to 45% relative to typical windows. The best result of cooling energy consumption was observed in Tehran. Conclusion: For this climate, the average energy consumption dropped to 34% for the warm months of the year and even 42% for the warmest month of the year (August).

Process Analysis of Ocean Thermal Energy Used for Desalination

2013 ◽  
Vol 724-725 ◽  
pp. 1242-1248
Author(s):  
Zhi Jiang Jin ◽  
Hao Wang
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Process Model ◽  
Process Analysis ◽  
Conventional Technique ◽  
Ocean Energy ◽  
Unit Energy ◽  
Lower Temperature ◽  
Ocean Thermal Energy ◽  
Direct Use

Ocean thermal energy (OTE) is a kind of ocean energy with a large development potential. In this paper, a new method making direct use of OTE for desalination was put forward and its principles and working process were also expounded. Firstly, this paper established the relevant process model of OTE desalination system. The system used OTE to maintain a vacuum and seawater could be evaporated at a much lower temperature and with less energy than conventional technique. Secondly, a parametric study was carried out quantitatively. It analyzed the influence on the system’s operation of three main parameters (temperature, mass flow and energy consumption). Finally, this paper improved the energy efficiency of the system. The lowest unit energy consumption could reach 4.54kWh/m3. The results indicate the feasibility of OTE used for desalination and its competitiveness against common solar desalination method.

scholarly journals Reduction of Energy Intensity in Broiler Facilities: Methodology and Strategies

2021 ◽  
Vol 8 ◽  
Author(s):  
Catherine Baxevanou ◽  
Dimitrios Fidaros ◽  
Ilias Giannenas ◽  
Eleftherios Bonos ◽  
Ioannis Skoufos
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Thermal Energy ◽  
Energy Intensity ◽  
Electrical Energy ◽  
Energy Performance ◽  
Advanced Technology ◽  
Energy Audit ◽  
Wind Potential ◽  
Technology Level

Broiler facilities consume a lot of energy resulting in natural source depletion and greater greenhouse gas emissions. A way to assess the energy performance of a broiler facility is through an energy audit. In the present paper, an energy protocol for an energy audit is presented covering both phases of data collection and data elaboration. The operational rating phase is analytically and extendedly described while a complete mathematical model is proposed for the asset rating phase. The developed energy audit procedure was applied to poultry chambers located in lowland and mountainous areas of Epirus Greece for chambers of various sizes and technology levels. The energy intensity indices varied from 46 to 89 kWh/m2 of chamber area 0.25–0.48 kWh/kg of produced meat or 0.36–1.3 kWh/bird depending on the chamber technology level (insulation, automation, etc.) and the location where the unit was installed. The biggest energy consumer was heating followed by energy consumption for ventilation and cooling. An advanced technology level can improve energy performance by ~ 27%−31%. Proper insulation (4–7 cm) can offer a reduction of thermal energy consumption between 10 and 35%. In adequately insulated chambers, the basic heat losses are due to ventilation. Further energy savings can be achieved with more precise ventilation control. Automation can offer additional electrical energy saving for cooling and ventilation (15–20%). Energy-efficient lights can offer energy saving up to 5%. The use of photovoltaic (PV) technology is suggested mainly in areas where net-metering holds. The use of wind turbines is feasible only when adequate wind potential is available. Solar thermal energy is recommended in combination with a heat pump if the unit's heating and cooling systems use hot/cold water or air. Finally, the local production of biogas with anaerobic fermentation for producing thermal or electrical energy, or cogenerating both, is a choice that should be studied individually for each farm.

scholarly journals Improving performance of direct expansion air conditioning systems while reducing electricity consumption through using hybrid energy

2021 ◽  
Vol 289 ◽  
pp. 01014
Author(s):  
Ahmed Al–Okbi ◽  
Yuri Vankov ◽  
Hakim Kadhim
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Air Conditioning ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Electricity Production ◽  
Conventional System ◽  
Solar Thermal Energy ◽  
Continuous Power ◽  
Air Conditioning Systems

At the present time, operating hybrid air-conditioning systems that use solar energy to saving electrical energy while improving the performance has become necessary to protect the environment, reduce pollution and emissions caused by using fuels and gases. In Iraq, temperatures reach half the boiling point at summer, therefore the demand for air conditioning systems increases, air conditioning systems consume more than half of average electricity production which affects on reliability and stability of the electrical energy thus leads to a continuous power outage. So, the issue of using renewable energies becomes more attractive. Because of saving energy leads to ensuring the reliability of electricity and reduces the consumption of fuels and gases that pollute on the environment and negatively affect on the ozone layer. In the current research, the atmosphere of Baghdad city was used to collect solar thermal energy and convert it into thermal energy through an evacuated solar collector by water and combine it with a conventional air conditioner in the part that follows the compressor in order to reduce the electrical energy consumption on the compressor and increase coefficient of performance. Several tests were conducted on the proposed system to compare results with the conventional system and evaluate performance. The results showed that the coefficient of performance with the hybrid system became 8.97 more efficient instead of 4.27 compared to the conventional system, and the energy consumption decreased by 52%.

scholarly journals Modifikasi Pengering Tipe Tray Dryer Dengan Penambahan Insulator

2020 ◽  
Vol 4 (4) ◽  
pp. 422-431
Author(s):  
Iqbal Fahri Tobing ◽  
Mustaqimah Mustaqimah ◽  
Raida Agustina
Keyword(s):  
Energy Consumption ◽  
Thermal Energy ◽  
Performance Test ◽  
Raw Materials ◽  
Electric Energy ◽  
Electrical Energy ◽  
Energy Calculation ◽  
Drying Process ◽  
Drying Time ◽  
Drying Efficiency

Abstrak. Pengering tipe Tray Dryer merupakan salah satu alat pengering rak atau pengering kabinet yang dapat digunakan untuk mengeringkan berbagai jenis bahan baku makanan. Alat pengering ini dirancang dengan tipe paralel flow tray dimana udara panas yang dihasilkan akan disirkulasikan sejajar dengan permukaan rak pengering dan bekerja menggunakan sumber energi listrik. Penelitian ini bertujuan untuk memodifikasi pengering tray dryer dengan penambahan insulator dan mengetahui konsumsi energi alat pengering tray dryer pada pengeringan kunyit. Parameter pengujian uji kinerja alat tanpa bahan meliputi distribusi suhu, kelembaban relatif dan kecepatan aliran udara dan untuk perhitungan konsumsi energi meliputi penggunaan energi listrik, perhitungan energi thermal, energi mengeringkan bahan, energi untuk menguapkan air bahan, efisiensi pengeringan, energi kipas dan kehilangan energi melalui cerobong. Pada pengujian pengering tray dryer suhu yang digunakan adalah 55°C. Hasil penelitian menunjukkan bahwa secara fungsional dan struktural alat pengering tray dryer setelah dimodifikasi dengan melapisi dinding luar ruang pengering dapat beroperasi dengan baik, proses pengeringan lebih cepat dan energi yang digunakan juga sedikit dibandingkan dengan sebelum dimodifikasi. Konsumsi energi listrik pada alat pengering tray dryer setelah dimodifikasi pada saat proses pengeringan dengan suhu 35oC selama 6,5 jam sebesar 35,33 kWh (127,2 MJ), pada suhu 45oC sebesar 24,26 kWh (88,06 MJ) dengan lamanya pengeringan selama 4,5 jam dan suhu 55oC sebesar 18,89 kWh (68,01 MJ) dengan lama pengeringan selama 3,5 jam, hal ii disebabkan lama pengeringan merupakan salah satu faktor yang menyebabkan besar kecilnya konsumsi energi listrik. Konsumsi energi thermal selama proses pengeringan dengan suhu 35°C adalah sebesar 17,53 MJ, suhu 45°C sebesar 19,54 MJ dan suhu 55°C sebesar 21,34 MJ. Berdasarkan hasil kalkulasi antara energi listrik dan energi thermal didapatkan efisiensi pengeringan pada suhu 35°C sebesar 27,80%, suhu 45°C sebesar 22,2% dan suhu 55°C sebesar 31,4%.Modification Of Tray Dryer With InsulatorAbstract. Tray Dryer is a type of dryer or cabinet dryer that can be used to dry various types of food raw materials. This dryer is designed with a parallel flow tray type where the hot air generated will be circulated parallel to the surface of the drying rack and work using an electric energy source. This study aims to modify the tray dryer with the addition of an insulator and determine the energy consumption of dryer dryers in turmeric drying. The test parameters of the performance test of equipment without material include temperature distribution, relative humidity and air flow velocity and for the calculation of energy consumption including the use of electrical energy, thermal energy calculation, energy drying material, energy to evaporate material water, drying efficiency, fan energy and energy loss through chimney. In testing the tray dryer dryer the temperature used is 55 ° C. The results showed that functionally and structurally the tray dryer after being modified by covering the outer walls of the drying chamber could operate well, the drying process was faster and the energy used was also less compared to before it was modified. Electric energy consumption in the tray dryer after being modified during the drying process with a temperature of 35oC for 6.5 hours amounted to 35.33 kWh (127.2 MJ), at a temperature of 45oC of 24.26 kWh (88.06 MJ) with a duration drying for 4.5 hours and a temperature of 55oC of 18.89 kWh (68.01 MJ) with a drying time of 3.5 hours, this is due to the length of drying is one of the factors causing the size of the electrical energy consumption. The consumption of thermal energy during the drying process with a temperature of 35 ° C is 17.53 MJ, a temperature of 45 ° C is 19.54 MJ and a temperature of 55 ° C is 21.34 MJ. Based on the results of calculations between electrical energy and thermal energy obtained drying efficiency at a temperature of 35 ° C at 27.80%, a temperature of 45 ° C at 22.2% and a temperature of 55 ° C at 31.4%

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