DETERMINING THE PROFITABILITY OF GREENHOUSE ELECTROTECHNOLOGIES: A MODELING APPROACH

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.

2013 ◽  
Vol 316-317 ◽  
pp. 176-180 ◽  
Author(s):  
Xue Jing Zheng ◽  
Meng Jun Yang ◽  
Wan Dong Zheng ◽  
Yun Kun Bu

Sino-Singapore Tianjin Eco-city is a strategic cooperation project between China and Singapore to improve the living environment and build an eco-culture. Animation-park covers an area of 1 km2, with a total construction area of 7.7x105m2. Wide sources of the renewable energy, such as solar hot water system, ground source heat pump system, solar PV power generation system, and deep geothermal energy system, is strongly recommended to use in eco-city in order to save energy and protect the environment. The usage of renewable energy is seen as a complement to the conventional energy. The energy consumption of the animation park is 42926tce of coal per year, and the renewable energy that used is 4573.6tce of coal per year. The usage of renewable energy leads to the reduction in the emission of CO2 of 18895.9t per year.


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 2020 ◽  
Author(s):  
Jeffrey Spitler ◽  
Signhild Gehlin

When the new student center at Stockholm University in Sweden was completed in the fall of 2013 it was thoroughly instrumented. The 6300 m2 four-story building with offices, a restaurant, study lounges, and meeting rooms was designed to be energy efficient with a planned total energy use of 25 kWh/m2/year. Space heating and hot water are provided by a ground source heat pump (GSHP) system consisting of five 40 kW off-the-shelf water-to-water heat pumps connected to 20 boreholes in hard rock, drilled to a depth of 200 m. Space cooling is provided by direct cooling from the boreholes. This paper uses measured performance data from Studenthuset to calculate the actual thermal performance of the GSHP system during one of its early years of operation. Monthly system coefficients-of-performance and coefficients-of-performance for both heating and cooling operation are presented. In the first months of operation, several problems were corrected, leading to improved performance. This paper provides long-term measured system performance data from a recently installed GSHP system, shows how the various system components affect the performance, presents an uncertainty analysis, and describes how some unanticipated consequences of the design may be ameliorated. Seasonal performance factors (SPF) are evaluated based on the SEPEMO (“SEasonal PErformance factor and MOnitoring for heat pump systems”) boundary schema. For heating (“H”), SPFs of 3.7 ± 0.2 and 2.7 ± 0.13 were obtained for boundaries H2 and H3, respectively. For cooling (“C”), a C2 SPF of 27 ± 5 was obtained. Results are compared to measured performance data from 55 GSHP systems serving commercial buildings that are reported in the literature.


2019 ◽  
Vol 111 ◽  
pp. 06075
Author(s):  
Calin Sebarchievici

A ground-coupled heat pump system (GCHP) and an air source heat pump (ASHP) driven by photovoltaic panels are used to provide domestic hot preparation for a NZEB house. The experimental measurements are used to test both the heat pump models in the same conditions of water temperature and volume of domestic hot water. A comparative analysis of the two heat pumps for domestic hot water preparation is performed. In addition, using the software TRNSYS (Transient Systems Simulation), two numerical simulation models of thermal and electrical energy consumption in DHW mode are developed. Finally, the simulations obtained using TRNSYS software are analysed and compared to the experimental data.


2012 ◽  
Vol 598 ◽  
pp. 31-36
Author(s):  
Li Wang ◽  
Qi Sheng Zhu ◽  
Yan Liu Zhou

This paper is based on the general condition that renewable energy resources used in buildings in Guangxi subtropical regions. By integrating the case of 9# dormitory building in Bowen College, Guilin University of Technology, making compare and contrast to the effectiveness of using ground source heat pump system, air source heat pump system , solar electric water heaters under such condition, taking the effectiveness of using renewable energy resources in air source heat pump system, the author discuss the issue of renewable energy resources system and the integration of buildings and provides some suggestions.


2013 ◽  
Vol 837 ◽  
pp. 763-768
Author(s):  
Andrei Preda ◽  
Andrei Alexandru Scupi

Despite the low energy and lower maintenance benefits of marine heat pump systems, little work has been undertaken in detailed analysis and simulation of such systems. This heat pump system is very attracting increasing research interests, since the system can be powered by thermal energy that can be provided by a renewable source: the difference of temperature between the ocean water layers.This paper focuses on the annual energy consumption and COP ( performance coefficent) of a marine heat pump system implemented for comercial use. This unconventional maritime systems of energy transfer would solve some of the pollution problems that arise from the use of conventional fuels . By using this system can make a pretty big energy savings in heating our homes and in preparation of hot water for domestic use.This energy consumption takes into account the heating and cooling needs of structure along different periods of time, such as winter and summer. Moreover, for each year period, we compared the heat pump efficiency simulated for our cost line with other tree tipes of heat pumps that are using diffrents primary agents. To highlight the performance of heat pump used for this study we coupled it with solar panels. The simulation, performed with TRNSYS (Transient Systems Simulation Program), was made for different working conditions simulating real conditions and temperature variations that occur in a year in the Black Sea coastal area.This experiment is intended to emphasize that marine energy potential that we have and also the advantages of using unconventional energy in relation to the use of classic fuels.This unconventional system of thermal energy conversion can be applied to both residential and commercial areas bringing an important benefit both people and the environment.


2013 ◽  
Vol 671-674 ◽  
pp. 2122-2125
Author(s):  
Qi Wang ◽  
Qiang Wang ◽  
Xiao Yang Hui ◽  
Zhi Jun Shi

Composition and operating modes of two different solar-assisted heat pump systems have been introduced in this paper. The advantages of compound heat pump system are analyzed compared with solo heat pump system. Solar-assisted air source heat pump system not only has the advantages, which air source heat pump system (ASHP) has, but also makes good use of renewable solar energy. It can provide cooling, heating and living hot water all the year. Solar-assisted ground source heat pump system realizes advantage complementation in various seasons between solar heat water system and ground source heat pump (GSHP) system. Solar-assisted ground source heat pump system can adjust the system operating model to solve the disadvantage of sole GSHP system, whose performance decrease for the temperature change of soil for long time operating with annual cool and heat unbalancedness. GSHP system can effectively increase the operating stability with the assistance of solar energy.


Energies ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 211 ◽  
Author(s):  
Piljae Im ◽  
Xiaobing Liu ◽  
Hugh Henderson

The wastewater leaving from homes and businesses contains abundant low-grade energy, which can be utilized through heat pump technology to heat and cool buildings. Although the energy in the wastewater has been successfully utilized to condition buildings in other countries, it is barely utilized in the United States, until recently. In 2013, the Denver Museum of Nature & Science at Denver, the United States implemented a unique heat pump system that utilizes recycled wastewater from a municipal water system to cool and heat its 13,000 m2 new addition. This recycled water heat pump (RWHP) system uses seven 105 kW (cooling capacity) modular water-to-water heat pumps (WWHPs). Each WWHP uses R-410A refrigerant, has two compressors, and can independently provide either 52 °C hot water (HW) or 7 °C chilled water (CHW) to the building. This paper presents performance characterization results of this RWHP system based on the measured data from December 2014 through August 2015. The annual energy consumption of the RWHP system was also calculated and compared with that of a baseline Heating, Ventilation, and Air Conditioning (HVAC) system which meets the minimum energy efficiencies that are allowed by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 90.1-2013. The performance analysis results indicate that recycled water temperatures were favorable for effective operation of heat pumps. As a result, on an annual basis, the RWHP system avoided 50% of source energy consumption (resulting from reduction in natural gas consumption although electricity consumption was increased slightly), reduced CO2 emissions by 41%, and saved 34% in energy costs as compared with the baseline system.


2013 ◽  
Vol 325-326 ◽  
pp. 379-383
Author(s):  
Jian Lv ◽  
Xiao Hong Ma ◽  
Shu Ai Zhen ◽  
Ying Zhang

Through testing the operation of solar energy-water source heat pump hot water system, analysis of the factors that affect system performance, research engineering optimization strategies for improving systems performance. Given some optimization recommendations for both solar energy system and water source heat pump system. Provide some supports for this new technology which use renewable energy in the future development.


Author(s):  
D.S. Elistratov

Heat-nosed technologies are widely available all over the world. In some countries, up to 70% of the need for thermal energy is provided by this technology.  Heat pumps in heating and hot water systems operate on a specific cycle. The work cycle involves starting a heat pump, heating the coolant and stopping. The number and duration of cycles depend on the need for thermal energy. When starting and getting to work mode, the heat pump works in an unsteady mode. This article is dedicated to the study of this regime.


2020 ◽  
Vol 182 ◽  
pp. 03006
Author(s):  
Yauheni Kachalouski ◽  
Matuška Tomáš

A performance of air-to-water and brine-to-water heat pump for domestic hot water preparation was analyzed in different climates of Europe. Air-source heat pumps are widely used energy source for domestic applications with low operation costs. Their system SPF was found at level of 3.0 for domestic hot water preparation for medium latitudes in Europe. Investigations on the ground-source heat pump performance show their average SPF are close to air-source technology.


Sign in / Sign up

Export Citation Format

Share Document