scholarly journals Development of a Wind Directly Forced Heat Pump and Its Efficiency Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Ching-Song Jwo ◽  
Zi-Jie Chien ◽  
Yen-Lin Chen ◽  
Chao-Chun Chien

The requirements of providing electric energy through the wind-forced generator to the heat pump for water cooling and hot water heating grow significantly by now. This study proposes a new technique to directly adopt the wind force to drive heat pump systems, which can effectively reduce the energy conversion losses during the processes of wind force energy converting to electric energy and electric energy converting to kinetic energy. The operation of heat pump system transfers between chiller and heat that are controlled by a four-way valve. The theoretical efficiency of the traditional method, whose heat pump is directly forced by wind, is 42.19%. The experimental results indicated average value for cool water producing efficiency of 54.38% in the outdoor temperature of 35°C and the indoor temperature of 25°C and the hot water producing efficiency of 52.25% in the outdoor temperature and the indoor temperature both of 10°C. We proposed a method which can improve the efficiency over 10% in both cooling and heating.

2021 ◽  
pp. 1-31
Author(s):  
Taoufik Brahim ◽  
Jemni Abdelmajid

Abstract A novel dual tank PV/T indirect parallel solar assisted heat pump system (DTPV/T-ISAHP) was investigated in this paper, which filled a gap in the literature. Furthermore, a long-term performance study analysis was performed under Tunisian climate to offset domestic electric and hot water loads. Optimal operations of such a system are achieved based on a simplified mathematical model. Results showed that the average thermal and electric energy efficiency is about 39.65% and 11.38%, respectively. Results revealed that the increase in solar radiation results in an improvement of the system's thermal-based COP efficiency coefficient reaching 4.49 at 893 W/m2. PV/T average electrical energy output is found to 0.68 kWh/m2/day with an annual average of 177.42 kWh/m2, which leads to an annual electricity surplus of about 5.83%. A reversible heat pump operation seemed more advantageous especially in the summer months, reducing yearly electric demand by about 84.57%. An economic analysis is undertaken and a payback period of about 12.7 years is found. The current study provided a framework for assessing such a system's behavior and providing useful flexibility to achieve the best possible system performance.


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 ◽  
Author(s):  
Toktam Saeid

In October 2009, Team North competed in the US DOE 2009 Solar Decathlon competition. Team North's mission was to design and deliver North House, an energy efficient solar-powered home while training Canada's next generation of leaders in sustainable design. In North House, the PV system on the roof was the primary energy generation, complimented by a custom PV cladding system on the south, east and west facades. A solar assisted heat pump system, including a three-tank heat transfer and storage system, the horizontally mounted evacuated-tube solar thermal collectors on the roof and a variable capacity heat pump met the hot water and space heating demands. A second variable capacity heat pump was utilized for space cooling. The solar thermal system was studied using TRNSYS simulation. For the initial assessments the simulations were run for Baltimore. Then, the analyses were extended to different cities across Canada. In all scenarios the same house was linked to the system. The minimum annual solar fraction of the different cities was 64% and it rose up to 81%. Finally, the data measured during the competition were analyzed and compared with the data resulting from the simulation. According to competition measures, during the 10 days of competition in Washington DC, the PV system generated 271.6kWh of electricity and the solar thermal system produced 91.7kWh while the house consumption was 294.1kWh. As a result, North House was evidently a net-positive house.


2011 ◽  
Vol 374-377 ◽  
pp. 398-404 ◽  
Author(s):  
Ying Ning Hu ◽  
Ban Jun Peng ◽  
Shan Shan Hu ◽  
Jun Lin

A hot-water and air-conditioning (HWAC) combined ground sourse heat pump(GSHP) system with horizontal ground heat exchanger self-designed and actualized was presented in this paper. The heat transfer performance for the heat exchanger of two different pipe arrangements, three layers and four layers, respectively, was compared. It showed that the heat exchange quantity per pipe length for the pipe arrangement of three layers and four layers are 18.0 W/m and 15.0 W/m. The coefficient of performance (COP) of unit and system could remain 4.8 and 4.2 as GSHP system for heating water, and the COP of heating and cooling combination are up to 8.5 and 7.5, respectively. The power consumption of hot-water in a whole year is 9.0 kwh/t. The economy and feasibility analysis on vertical and horizontal ground heat exchanger were made, which showed that the investment cost per heat exchange quantity of horizontal ground heat exchanger is 51.4% lower than that of the vertical ground heat exchanger, but the occupied area of the former is 7 times larger than the latter's.


Author(s):  
Lanbin Liu ◽  
Lin Fu ◽  
Yi Jiang

Typically there is a great deal of waste heat available in drainage system of large-scale public bathhouses, such as public bathhouses in schools, barracks and natatoriums. The paper advances a heat pump system used in bathhouses for exhaust heat recovery. The system consists of solar energy collection system, drainage collection system and heat pump system for exhaust heat recovery. In the system, tap water is heated by energy from solar energy collection system, and is used as hot water for bathing at the beginning. At the same time, drainage collection system collects sewage from bathhouses, and then electric heat pump starts up and recovers the exhaust heat in sewage and heats the tap water. In this way, heat is recycled. Practical operation of the system was introduced, and drainage temperature as well as equipment capacity was optimized based on a practical example. Compared with gas-fired (oil-fired, coal-fired, electric) boilers, the system has advantages of lower energy consumption, less pollution and lower operating cost. Therefore, the system has great superiority in energy conservation and has a good application prospect.


Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3776
Author(s):  
Nguyen Van Duc Long ◽  
Thi Hiep Han ◽  
Dong Young Lee ◽  
Sun Yong Park ◽  
Byeng Bong Hwang ◽  
...  

Distillation for R-410A reclamation from a waste refrigerant is an energy-intensive process. Thus, various heat pump configurations were proposed to enhance the energy efficiency of existing conventional distillation columns for separating R-410A and R-22. One new heat pump configuration combining a vapor compression (VC) heat pump with cold water and hot water cycles was suggested for easy operation and control. Both advantages and disadvantages of each heat pump configuration were also evaluated. The results showed that the mechanical vapor recompression heat pump with top vapor superheating saved up to 29.5%, 100.0%, and 10.5% of the energy required in the condenser duty, reboiler duty, and operating cost, respectively, compared to a classical heat pump system, and 85.2%, 100.0%, and 60.8%, respectively, compared to the existing conventional column. In addition, this work demonstrated that the operating pressure of a VC heat pump could be lower than that of the existing distillation column, allowing for an increase in capacity of up to 20%. In addition, replacing the throttle valve with a hydraulic turbine showed isentropic expansion can decrease the operating cost by up to 20.9% as compared to the new heat pump configuration without a hydraulic turbine. Furthermore, the reduction in carbon dioxide emission was investigated to assess the environmental impact of all proposed sequences.


2012 ◽  
Vol 238 ◽  
pp. 478-481
Author(s):  
Zhen Qing Wang ◽  
Yan Chen ◽  
Hai Xia Wang

An air source heat pump system (ASHPS) was set up, which provided space heating and cooling, as well as hot water for an office building in Tianjin. Its operating performance in winter was evaluated based on test data. Considering the local abundant solar radiation and the way to provide energy in an office building, a simulation study was carried out on the combsystem of ASHP and flat plate air collector (FPAC). The effects of collector area and its outlet parameters on the heating performance of ASHP were studied, and the favorable operating and matching mode were recommended. The results indicate that ASHPS is a technically viable method in Tianjin in winter, but not economically, and the air-solar combsystem should be taken into account for its massive replacement for conventional energy.


Sign in / Sign up

Export Citation Format

Share Document