scholarly journals Coverage of energy for the preparation of hot tap water by installing solar collectors in a singlefamily building

2018 ◽  
Vol 49 ◽  
pp. 00106
Author(s):  
Aleksander Starakiewicz

The paper presents the results of experimental studies on the consumption of hot water, energy obtained from the solar installation in the production process and the degree of coverage of usable and final energy with solar collectors. Thermal energy measurements from solar collectors cover the measurement period from 2011 to 2017. During this period, the annual final energy obtained from solar collectors ranged from 1033-1576 kWh. Monthly and annual demand for usable and final energy for the demand for hot water is presented depending on the amount of hot water used. Monthly actual consumption of hot water in the measurement period ranged from 3.57-9.16 m3. During this period, the number of residents has changed from 3 to 5 people. Annual coverage of energy useful for heat and energy by solar panels in the years 2011-2017 fluctuated from 38.0%-63.9% and 25.2%-42.3% for final energy. Monthly energy coverage ranged from 5.5% to over 100%. Covering energy above 100% in practice means getting a higher temperature of hot water in the outlet valve than expected.

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5137
Author(s):  
Paweł Ocłoń ◽  
Maciej Ławryńczuk ◽  
Marek Czamara

The objectives of this work are: (a) to present a new system for building heating which is based on underground energy storage, (b) to develop a mathematical model of the system, and (c) to optimise the energy performance of the system. The system includes Photovoltaic Thermal Hybrid Solar Panels (PVT) panels with cooling, an evacuated solar collector and a water-to-water heat pump. Additionally, storage tanks, placed underground, are used to store the waste heat from PVT panels cooling. The thermal energy produced by the solar collectors is used for both domestic hot water preparation and thermal energy storage. Both PVT panels and solar collectors are assembled with a sun-tracking system to achieve the highest possible solar energy gain. Optimisation of the proposed system is considered to achieve the highest Renewable Energy Sources (RES) share during the heating period. Because the resulting optimisation problem is nonlinear, the classical gradient-based optimisation algorithm gives solutions that are not satisfying. As alternatives, three heuristic global optimisation methods are considered: the Genetic Algorithm (GA), the Particle Swarm Optimisation (PSO) algorithm, and the Jaya algorithm. It is shown that the Jaya algorithm outperforms the GA and PSO methods. The most significant result is that 93% of thermal energy is covered by using the underground energy storage unit consisting of two tanks.


2018 ◽  
Vol 82 (1) ◽  
Author(s):  
Юрий Анатольевич Селихов ◽  
Виктор Алексеевич Коцаренко

Европейские страны демонстрируют высокие возможности простого преоб­разования солнечной энергии в тепловую энергию, которая может успешно использо­ваться для обеспечения различного рода технологических, отопительных и бытовых потребностей. Кроме того, ввод в эксплуатацию сол­нечных установок улучшает экологическую ситуацию района потребления тепловой энер­гии за счет снижения объемов выбросов загряз­няющих веществ, к которым относятся продукты сгорания органического топлива, используемого для производства тепловой энергии. В настоящее время в южных районах Украины уже используются солнечные установки для горячего водоснабжения и отопления. Однако, внедрение новых энергетических и экономически выгодных установок идет медленными темпами, что объясняется довольно высокими стоимостными показате­лями, как отечественных, так и зарубежных установок. Таким образом, на наш взгляд, является актуальной концепция создания новых солнечных установок, наиболее привлекательных для потенциаль­ного потребителя. Реализация данной кон­цепции возможна при таком варианте исполнения солнечных установок, когда затраты на выработку тепловой энергии с помощью этих установок будут ниже уровня суммарных затрат на получение тепловой энергии традиционными способами (в частности, в котельных установках). Однов­ременно с этим, срок окупаемости солнечных установок должен быть соизмерим с гарантийным сроком их эксплуатации. Для выполнения поставленных условий представ­ляется целесообразным разработка таких конструкций солнечных коллекторов, которые позволяли бы минимизировать затраты на их изготовление, монтаж и обслуживание. Это может достигаться за счет использования дешёвых отечественных материалов, выпуск которых гарантирован в достаточных объемах на протяжении длительного срока. Разработка, изготовление и внедрение двухконтурных солнечных установок позволило круглогодично эксплуатировать солнечный коллектор, но капитальные и эксплуатационные затраты при этом были  на таком уровне, что для полной окупаемости солнечной установки могло понадобиться более пяти лет, так как солнечные коллектора изготавливались из металла.  В рамках сформулированной задачи нами был разработан и изготовлен солнечный коллектор из полиэтиленовой пленки. Предлагается двухконтурная солнечная установка для горячего водоснабжения и отопления, у которой солнечные коллектора изготовлены из полиэтиленовой пленки. Такая установка разработана, изготовлена и запущена в эксплуатацию в одном южном регионе Украины. На установке были получены экспериментальные результаты работы установки в разных режимах в течение года. После обработки этих данных были получены обобщающие зависимости: плотности теплового потока от температуры теплоносителя в коллекторе, времени работы установки в течение светового дня и расхода теплоносителя; коэффициента полезного действия от плотности теплового потока; максимального коэффициента полезного действия от максимальной плотности теплового потока; количества теплоты при конвекции от скорости натекания ветрового потока от 1 до 6 м/с на внешнюю поверхность солнечного коллектора. Зависимости получены при разных объемных расходах V от 0,5 до 3,0 м3/ч теплоносителя. Максимальная погрешность проведенных расчетов не превышает 5 %.  European countries demonstrate high opportunities for simple conversion of solar energy into thermal energy, which can be successfully used to provide various types of technological, heating and domestic needs. In addition, the commissioning of salt plants improves the ecological situation in the area of consumption of thermal energy by reducing emissions of polluting substances, which include combustion products of organic fuel used for the production of thermal energy.  At present, solar installations for hot water supply and heating are already used in the southern regions of Ukraine. However, the introduction of new energy and economically advantageous plants is proceeding slowly, which is explained by rather high cost indices, both domestic and foreign installations.Thus, in our opinion, the concept of creating new solar installations that are most attractive to a potential consumer is relevant. Implementation of this concept is possible with such an option of solar installations, when the cost of generating thermal energy using these facilities will be lower than the total cost of obtaining thermal energy by traditional methods (in particular, in boiler plants). However, with this, the payback period of solar installations should be commensurate with the warranty period of their operation. To fulfill the set conditions it is advisable to develop such designs of solar collectors that would allow to minimize the costs of their manufacture, installation and maintenance. This can be achieved through the use of cheap domestic materials, the release of which is guaranteed in sufficient quantities over a long period. The development, production and implementation of dual-circuit solar installations allowed the solar collector to be operated year-round, but the capital and operating costs were at such a level that it would take more than five years to fully pay for the solar installation, since the solar collectors were made of metal. Within the framework of the formulated task, we developed and manufactured a solar collector made of polyethylene film. A double-circuit solar installation is proposed for hot water supply and heating, in which the solar collectors are made of polyethylene film. Such an installation is designed, manufactured and commissioned in one southern region of Ukraine. Experimental results of the installation in different modes during the year were obtained at the plant. After processing of these data, generalizing dependencies were obtained: the heat flux density from the coolant temperature in the collector, the operating time of the installation during the daylight and the flow of the coolant; coefficient of efficiency from the density of heat flow; the maximum efficiency from the maximum heat flux density; the amount of heat in convection from the rate of leakage of the wind flow from 1 to 6 m / s on the outer surface of the solar collector. Dependencies were obtained at different volumetric flows V from 0.5 to 3.0 m3 / h of the heat carrier. The maximum error in the calculations does not exceed 5%.


TECCIENCIA ◽  
2020 ◽  
Vol 16 (30) ◽  
pp. 29-52
Author(s):  
Juan Andres Avila Carraznza ◽  
Carlos Mario Rocha ◽  
Juan Sebastian Solis Chavez

The use of Flat Solar Collectors for the generation of Domestic Hot Water (DHW), facilitates access to this resource in an efficient, economical and sustainable way. The Sustainable Development Goals proposed by the UN, referring specifically to sustainable water management and access to renewable energy, are the main motivation for this work, since the former is an essential vital resource and its access reduces the inequality index, in developing countries such as Colombia, while the use of solar thermal energy reduces the environmental impact of the water heating process, thus reducing the consumption of electrical energy in the residential sector. Therefore, this work proposes to estimate DHW profiles through a spreadsheet that models the DHW flow thermodynamically for a whole year, making it possible to evaluate the energy performance of a Solar Collector available in the Colombian market and that is used in four types of dwellings located in the city of Bogotá. The simulation results present the DHW consumption profiles in kg/h per year, with DHW temperatures of up to 21°C, for a total transmitted irradiance of the order of 1100 W/m^2, which produces thermal energy close to 1kW. This comparative analysis allows us to review the technical and economic feasibility of solar collectors installed in single-family homes and with a DHW consumption profile close to the Colombian socio-economic reality


Author(s):  
Refat Mohammed Abdullah Eshaq ◽  
Eryi Hu ◽  
Ameen A Alshaba ◽  
Aiman A.M Alsenwi

Purpose. Feasibility of completely dispensing with solar collectors (SCs) that are used in heat pump (HP) systems for hot water in cold areas. Methodology. Since the temperature of gearbox oil is relatively high, lots of heat can be exploited. Therefore, the recovery of this unutilized heat from gearbox oil temperature of a wind turbine shows a promising solution in improving heat pump (HP) efficiency for hot water especially in cold environment or the district that is located in the north of our planet where the solar energy is very low. This investigation focuses on the feasibility of direct conversion of mechanical energy harvested from the wind speed into thermal energy by exploiting only the friction phenomenon inside the gearbox of the wind turbine by completely dispensing with solar collectors (SCs) that are used in combined solar assisted heat pump (SAHP) because the SCs have various problems, such as large heat loss, low efficiency, freezing and tube-burst, which may limit their applications. Findings. Results show that the wind turbine can provide the power required for HP during the winter season due to high wind speed in Xuzhou city, Jiangsu, China particularly in January. At best, coefficient of performance (COP) may reach 4.08 without SCs, thus the suggested system ensures high COP in addition to decrease in the fuel consumption by 23.25%. Originality. Wind power driven HPs have been suggested in many pervious papers as a sustainable measure to provide heat to a house; however, to improve COP of HP system, we suggest using a wind turbine to directly drive the HP and exploit gearbox oil temperature in an assistant heat exchanger installed after the HP evaporator for providing additional thermal energy to refrigerant R12 and cooling the gearbox oil. Practical value. The coefficient of performance (COP) of HP has reached 4.08 without SCs, so the suggested system demonstrates high COP in addition to the reduced fuel consumption. Approximately 23.25% of energy could be saved using this novel system compared to a fuel water heater for DHW.


2020 ◽  
Vol 7 (1) ◽  
pp. G9-G14
Author(s):  
S. Shkrylova ◽  
V. Kostenko ◽  
I. Skrynetska

In the conditions of the global ecological crisis in the world and Ukraine, the issue of finding alternative energy sources becomes relevant. One of the most common types of renewable energy is solar energy. In Ukraine today, the most promising direction of using solar energy is its direct transformation into low-potential thermal energy. To get electric power, solar radiation is the mere alternative to electric power generated from mined fuel, and without the pollution of air and water, or adverse consequences manifested in global warming. The disadvantage of this type of installation is the limitation of the duration of light time, as well as the effect of cloudiness. During the day, the number of solar radiation changes, to stabilize it is necessary to accumulate and accumulate it for further use, the technical implementation of stable operation of solar installation due to the use of terrestrial radiation and the accumulator of a specific part of solar energy is proposed. The purpose of the work is experimental studies to ensure the stable operation of the solar collector under cloudy conditions. The paper is aimed at the stabilization of the operation of the solar installation and to obtain additional heat after the Sun’s cloud cover. The use of a solar thermal collector is advisable in solar heating and hot water systems in conditions of alternating solar radiation. The results of physical modeling have proved the efficiency of the method of combining types of thermal radiation, due to the accumulation of energy it is possible to increase the quantitative index of solar energy in the conditions of cloudiness by 3 times Keywords: alternative energy, solar energy, solar collector, thermal energy, clouds, terrestrial radiation, ecology.


TECCIENCIA ◽  
2021 ◽  
Vol 16 (31) ◽  
pp. 29-52
Author(s):  
Juan Andrés Ávila Carranza ◽  
Carlos Mario Rocha-Osorio ◽  
Juan Sebastián Solís-Chave

The use of Flat Solar Collectors for the generation of Domestic Hot Water (DHW), facilitates access to this resource in an efficient, economical and sustainable way. The Sustainable Development Goals proposed by the UN, referring specifically to sustainable water management and access to renewable energy, are the main motivation for this work, since the former is an essential vital resource and its access reduces the inequality index, in developing countries such as Colombia, while the use of solar thermal energy reduces the environmental impact of the water heating process, thus reducing the consumption of electrical energy in the residential sector. Therefore, this work proposes to estimate DHW profiles through a spreadsheet that models the DHW flow thermodynamically for a whole year, making it possible to evaluate the energy performance of a Solar Collector available in the Colombian market and that is used in four types of dwellings located in the city of Bogotá. The simulation results present the DHW consumption profiles in kg/h per year, with DHW temperatures of up to 21°C, for a total transmitted irradiance of the order of 1100 W/m^2, which produces thermal energy close to 1kW. This comparative analysis allows us to review the technical and economic feasibility of solar collectors installed in single-family homes and with a DHW consumption profile close to the Colombian socio-economic reality.


Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4586 ◽  
Author(s):  
Zukowski ◽  
Radzajewska

One of the most effective ways to reduce greenhouse gas emissions is the widespread use of solar panels. A new approach to estimating the annual energy output ESC of liquid-based solar thermal collectors is presented in this paper. The main parameters of the surrounding environment that affect the energy yield from solar water heating (SWH) systems are total solar radiation ES and outdoor air temperature θO. Here, two functions are developed that allow the specification of the ESC value based on these two previously determined factors. The article presents the subsequent stages that led to the development of this method. In the first step, the computer model of a solar domestic hot water (SDHW) system was built in the EnergyPlus environment. An object of the modeling procedure was the real solar installation located at Bialystok University of Technology. The database containing the annual energy output of the solar collectors, total solar radiation, and outdoor air temperature was developed based on the results of simulations made for 24 Polish cities. Then, the multiple regression method (implemented in Statistica v.13.1) was used to correlate these variables. Two contour graphs were also developed to determine the energy yield from solar collectors.


2020 ◽  
Vol 180 ◽  
pp. 02014
Author(s):  
Liliana Dumitrescu ◽  
Corneliu Cristescu ◽  
Radu Rădoi ◽  
Ioan Pavel ◽  
Florian Dragomir ◽  
...  

The article presents an energy system solution in which the heat energy required to get domestic hot water needed for a family home is obtained by the cumulative conversion of energy from 2 renewable sources: solar energy and biomass energy. Compared to the classic variants of thermal systems, which exploit a single source and provide only partially the energy needed, the combined use consists of energy supply from one source when the other is unavailable or insufficient. In the present case, when the domestic hot water requirement is no longer covered by the solar thermal panels (consumption during the night, days without sun or temporary consumption higher than the usual one), energy from biomass is used in the same system. It is converted to thermal energy using a generator where the gasification module uses the TLUD process. In addition to a higher yield of biomass, this process allows the use of a wide range of biomass types, existing in rural areas. The article presents the results obtained from the experimentation of the system that uses 4 solar panels and a thermal energy generator with a power of approx. 10 kW.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2285 ◽  
Author(s):  
Dimitris Al. Katsaprakakis

The article examines the introduction of solar-combi systems in large-size sports facilities. The examined solar-combi systems consist of solar collectors, a biomass heater and thermal storage tanks. In a sense, they constitute hybrid thermal power plants. The full mathematical background is presented on the operation of such systems, along with a proposed operation algorithm, aiming at the maximization of the captured solar radiation. A case study is implemented for the coverage of the thermal energy needs for hot water production and swimming pools heating, met in the Pancretan Stadium, Crete, Greece. In this way, the article aims to indicate the technical and economic prerequisites that can guarantee the feasibility of the examined systems, highlighting the significant potential contribution of such systems towards the realization of energy transition plans from fossil fuels to renewables. The economic feasibility of the introduced system is based on the avoiding diesel oil and electricity procurement cost, consumed for the coverage of the thermal energy demands under consideration. The optimum dimensioning of the examined case study results to an annual thermal energy demand coverage balance of 55% by the solar collectors and 45% by the biomass heater, giving a payback period of 5–6 years.


2017 ◽  
Vol 22 ◽  
pp. 00044 ◽  
Author(s):  
Natalia Fidorów-Kaprawy ◽  
Edyta Dudkiewicz

The systems using solar energy, popular in Poland, can be used to supply hot water for the installation used by employees of industrial halls. In manufacturing plants, employing a large number of people, the demand for hot water is practically constant throughout the year and is characterized by periodic use at the end of each work shift. Dynamics of the hot water consumption depends on the number of shifts as well as working days and holidays. Additionally the maximum hot tap water demand occurs in the whole period of installation operation. In polish climatic conditions the solar collectors’ systems have the largest capacity in the summer, while in winter they need to be assisted. Beside that the supply of renewable energy is uneven and depends on weather conditions. In the paper the one-hour step analysis concerning the dependence of the load pattern of the hot tap water preparation system on the energy yield from solar collectors had been performed.


Sign in / Sign up

Export Citation Format

Share Document