scholarly journals Economic and environmental benefits of a novel multi-functional heat pump system for dishwasher

2019 ◽  
Vol 118 ◽  
pp. 03029
Author(s):  
Wei Dong ◽  
Yongcun Li

In present study, a novel heat pump named multi-functional heat pump systems for dishwashers is introduced. 45 oC hot water cycle and hot air cycle are provided by the single-stage heat pump cycle to complete the cleaning and drying process. Moreover, the high temperature water at 85 °C is provided by the two-stage heat pump cycle system to achieve the disinfection function, and the 26°C cold air is realized by the single-stage refrigeration cycle for rapid cooling. Thermodynamic analysis of multi-functional heat pump systems for dishwashers under four different operating conditions with R22 / R134a as working fluid was carried out. The results show that COP (coefficient of performance) of the system is above 3.2 under all four conditions, which meets the energy efficiency rating index. Comparing energy efficiency and environmental benefits and operating costs of multi-functional heat pump systems for dishwashers with the traditional electric heating dishwashers, these can be known that primary energy consumption, carbon dioxide emissions and operating cost of multifunctional heat pump dishwasher are 1.24 * 105kJ, 10.55kg and 21.70 Yuan respectively under the condition of per running energy consumption for 40kW·h, above three all lower than the traditional electric heating dishwasher.

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.


2021 ◽  
Vol 13 (2) ◽  
pp. 983
Author(s):  
Mustapha Mukhtar ◽  
Bismark Ameyaw ◽  
Nasser Yimen ◽  
Quixin Zhang ◽  
Olusola Bamisile ◽  
...  

The world has not been able to achieve minimum greenhouse gas emissions in buildings’ energy consumptions because the energy and emissions optimization techniques have not been fully utilized. Thermal comfort is one of the most important issues for both residential and commercial buildings. Out of the 40% of global energy consumed by buildings, a large fraction is used to maintain their thermal comfort. In this study, a comprehensive review of the recent advancements in building energy conservation and efficiency application is presented based on existing high-quality research papers. Additionally, the retrofit of the heating/cooling and hot water system for an entire community in Cyprus is presented. This study aims to analyze the technical and environmental benefits of replacing existing electric heaters for hot water with heat pump water heating systems and the use of heat pump air conditioners for thermal comfort in place of the existing ordinary air conditioners for space heating and cooling. One administrative building, 86 apartments (including residential and commercial) buildings, and a restaurant building is retrofitted, and the feasibility of the project is determined based on three economic indicators, namely; simple payback period (SPP), internal rate of return (IRR), and net present value (NPV). The electrical energy required by the hot water systems and the heating/cooling system is reduced by 263,564 kWh/yr and 144,825 kWh/yr, respectively. Additionally, the retrofit project will reduce Cyprus’ CO2 emission by 121,592.8 kg yearly. The SPP, IRR, and NPV for the project show that the retrofit is economically feasible.


2016 ◽  
Author(s):  
Gabriel Agila ◽  
Guillermo Soriano

This research develops a detailed model for a Water to Water Heat Pump Water Heater (HPWH), operating for heating and cooling simultaneously, using two water storage tanks as thermal deposits. The primary function of the system is to produce useful heat for domestic hot water services according to the thermal requirements for an average household (two adults and one child) in the city of Quito, Ecuador. The purpose of the project is to analyze the technical and economic feasibility of implementing thermal storage and heat pump technology to provide efficient thermal services and reduce energy consumption; as well as environmental impacts associated with conventional systems for residential water heating. An energy simulation using TRNSYS 17 is carried to evaluate model operation for one year. The purpose of the simulation is to assess and quantifies the performance, energy consumption and potential savings of integrating heat pump systems with thermal energy storage technology, as well as determines the main parameter affecting the efficiency of the system. Finally, a comparative analysis based on annual energy consumption for different ways to produce hot water is conducted. Five alternatives were examined: (1) electric storage water heater; (2) gas fired water heater; (3) solar water heater; (4) air source heat pump water heater; and (5) a heat pump water heater integrated with thermal storage.


2011 ◽  
Vol 347-353 ◽  
pp. 587-590
Author(s):  
Qing Hai Luo ◽  
Zheng Zuo

This paper analyzes the energy consumption of hot water supply in buildings and the insurmountable shortcoming of low energy efficiency of conventional water heaters, and investigates the progress and problems of developing heat pump water heaters. It is pointed out that developing of heat pump water heaters is one of the efficient approaches to improve the energy efficiency of hot water supply.


Author(s):  
Jenny Chu ◽  
Cynthia A. Cruickshank ◽  
Wilkie Choi ◽  
Stephen J. Harrison

Heat pumps are commonly used for residential space-heating and cooling. The combination of solar thermal and heat pump systems as a single solar-assisted heat pump (SAHP) system can significantly reduce residential energy consumption in Canada. As a part of Team Ontario’s efforts to develop a high performance house for the 2013 DOE Solar Decathlon Competition, an integrated mechanical system (IMS) consisting of a SAHP was investigated. The system is designed to provide domestic hot water, space-heating, space-cooling and dehumidification. The system included a cold and a hot thermal storage tank and a heat pump to move energy from the low temperature reservoir, to the hot. The solar thermal collectors supplies heat to the cold storage and operate at a higher efficiency due to the heat pump reducing the temperature of the collector working fluid. The combination of the heat pump and solar thermal collectors allows more heat to be harvested at a lower temperature, and then boosted to a suitable temperature for domestic use via the heat pump. The IMS and the building’s energy loads were modeled using the TRNSYS simulation software. A parametric study was conducted to optimize the control, sizing and configuration of the system. This paper provides an overview of the model and summarizes the results of the study. The simulation results suggested that the investigated system can achieve a free energy ratio of about 0.583 for a high performance house designed for the Ottawa climate.


2021 ◽  
Vol 2095 (1) ◽  
pp. 012077
Author(s):  
Xiaoming Zhang ◽  
Qiang Wang ◽  
Qiujin Sun ◽  
Mingyu Shao

Abstract There have been few practical applications of solar coupled groundwater source heat pump (GWHP) systems in large public buildings, and data on this technology are scarce. A solar coupled GWHP system was investigated in this study. The system uses an underground water source heat pump system for heating in winter, cooling in summer, and providing part of the domestic hot water, and it also uses a solar energy system to prepare domestic hot water. These two types of energy are complementary. The system was tested throughout the cooling season. This experiment ran from May 10, 2021, to September 10, 2021. The results show that the system can guarantee the indoor design temperature and the supply of domestic hot water. The solar water heating system operated for 1233 min in the summer; hot water (2334 m3) was prepared. During the summer, the average energy efficiency ratio of the GWHP unit was approximately 4.88. The energy efficiency ratio of the entire system was approximately 3.34. Such projects can play a key role in demonstrating this type of system.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4306 ◽  
Author(s):  
Zhongting Hu ◽  
Sheng Zhang ◽  
Wenfeng Chu ◽  
Wei He ◽  
Cairui Yu ◽  
...  

The present work investigated a solar assisted heat pump system for drying Chinese wolfberry. The kinetic characteristic was firstly analyzed through a series of lab experiments. It was concluded that the Page model was the most suitable for predicting the heat and mass transfer of the wolfberry. Based on the wolfberry kinetic model, solar collector model and chamber air model, the coupled drying system model was developed. The accuracy of the mathematic model was determined through comparing with the preliminary experimental results. The influence of operating conditions on the thermal and energy performance of the dryer for the different operating mode was discussed. The drying weight of no more than 75 kg may be preferable in the stand-alone solar drying mode, and less than 15 h was needed to be dried. The electric energy consumption in the solar assisted the heat pump drying mode was lower than that in the stand-alone heat pump mode, and it was recommended that about 50 kg of wolfberry to be dried in the solar assisted heat pump system. Compared to the autumn drying, the reduction in the electric energy consumption was around 9.1 kWh during the 11 h summer drying process. The obtained results demonstrated the feasibility of the combined system for drying wolfberry, and also can provide the basic theoretical and experimental data support for the following research.


2014 ◽  
Vol 521 ◽  
pp. 757-761 ◽  
Author(s):  
Sheng Hao Xiao ◽  
Qing Hai Luo ◽  
Gao Feng Li

The discharge of the shower wastewater is not only caused energy waste, but also caused a certain thermal pollution to the environment. The thermoelectric heat pump system, compared with the electric heating device, has a more effective output of heat energy. By recycling heat of shower wastewater, it can be both energy-saving and environmental. With a growing ratio of the energy consumption of hot water, the thermoelectric heat pump system may give us a new perspective in the area of waste heat recovery and energy efficiency in buildings.


2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Jenny Chu ◽  
Wilkie Choi ◽  
Cynthia A. Cruickshank ◽  
Stephen J. Harrison

The combination of solar thermal and heat pump systems as a single solar assisted heat pump (SAHP) system can significantly reduce residential energy consumption in Canada. As a part of Team Ontario's efforts to develop a high performance house for the U.S. Department of Energy's Solar Decathlon 2013 Competition, an integrated mechanical system (IMS) consisting of a SAHP was investigated. The system was designed to provide domestic hot water (DHW), space-heating, space-cooling, and dehumidification. The system included a cold and a hot thermal storage tanks and a heat pump to move energy from the low temperature reservoir to the hot reservoir. Solar thermal collectors supplied heat to the cold storage and operated at a higher efficiency due to the heat pump reducing the temperature of the collector working fluid. The combination of the heat pump and solar thermal collectors allows more heat to be harvested at a lower temperature, and then boosted to a suitable temperature for domestic use via the heat pump. The IMS and the building's energy loads were modeled using the TRNSYS simulation software. A parametric study was conducted to optimize the control, sizing, and configuration of the system. The simulation results suggested that the investigated system can achieve a free energy ratio (FER) of about 0.583 for the high performance house designed for the Ottawa climate.


Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 356
Author(s):  
Fujen Wang ◽  
Kusnandar ◽  
Hungwen Lin ◽  
Minghua Tsai

With the cost of energy rising, the value of conservation grows. Interest in energy efficiency could be a sound investment or a necessary public policy. Heat pump systems provide economical alternatives of recovering heat from different sources for use in various applications. The objective of this study is to present the strategic approach on the energy efficient analysis of the water heating system retrofitted by applying a heat pump system in the dormitory of a university. Energy savings were determined by comparing field measurements of water consumption, water temperature and power consumption of the overall system before (electric resistance heating system) and after (heat pump heating system) the implementation of this project. Furthermore, the building energy simulation code (eQuest) has been applied to verify and predict the long-term energy consumption for both water heating systems. The results from energy modelling revealed the good agreement for energy simulation and field measurement data and the improvement of energy efficiency and energy savings could be achieved satisfactorily by retrofitting of a heat pump system. The energy conversion efficiency of hot water for energy consumption at 0.63 (Mcal/Mcal) could be achieved after the application of heat pump water heating system. It also presented the annual saving about USD 20,000 (NTD 600,000) for the dorm by using a heat pump heating system under the electrical billing rate of Taiwan.


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