scholarly journals Development and Validation of Air-to-Water Heat Pump Model for Greenhouse Heating

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4714
Author(s):  
Adnan Rasheed ◽  
Wook Ho Na ◽  
Jong Won Lee ◽  
Hyeon Tae Kim ◽  
Hyun Woo Lee
Keyword(s):  
Heat Pump ◽  
Storage Tank ◽  
Energy Requirement ◽  
Water Storage ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Water Storage Tank ◽  
National University ◽  
Heating Load ◽  
Development And Validation

This study proposes a building energy simulation (BES) model of an air-to-water heat pump (AWHP) system integrated with a multi-span greenhouse using the TRNSYS-18 program. The proposed BES model was validated using an experimental AWHP and a multi-span greenhouse installed in Kyungpook National University, Daegu, South Korea (latitude 35.53° N, longitude 128.36° E, elevation 48 m). Three AWHPs and a water storage tank were used to fulfill the heat energy requirement of the three-span greenhouse with 391.6 m2 of floor area. The model was validated by comparing the following experimental and simulated results, namely, the internal greenhouse temperature, the heating load of the greenhouse, heat supply from the water storage tank to the greenhouse, heat pumps’ output water temperature, power used by the heat pumps, coefficient of performance (COP) of the heat pump, and water storage tank temperature. The BES model’s performance was evaluated by calculating the root mean square error (RMSE) and the Nash–Sutcliffe efficiency (NSE) coefficient of validation results. The overall results correlated well with the experimental and simulated results and encouraged adopting the BES model. The average calculated COP of the AWHP was 2.2 when the outside temperature was as low as −13 °C. The proposed model was designed simply, and detailed information of each step is provided to make it easy to use for engineers, researchers, and consultants.

Energy-saving analysis of air source heat pump integrated with a water storage tank for heating applications

2020 ◽  
Vol 180 ◽  
pp. 107029
Author(s):  
Pin Wu ◽  
Zhichao Wang ◽  
Xiaofeng Li ◽  
Zhaowei Xu ◽  
Yingxia Yang ◽  
...  
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Storage Tank ◽  
Water Storage ◽  
Water Storage Tank ◽  
Air Source Heat Pump

A Sustainable Trigeneration System for Residential Applications

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Azzam Abu-Rayash ◽  
Ibrahim Dincer
Keyword(s):  
Heat Pump ◽  
Storage Tank ◽  
Renewable Energy Sources ◽  
Water Storage ◽  
Hot Water ◽  
Low Grade ◽  
High Grade ◽  
Pump System ◽  
Water Storage Tank ◽  
Energy And Exergy

Abstract This paper features the integration of two renewable energy sources, making a new trigeneration system for residential applications. The system is primarily powered by solar photovoltaic-thermal (PVT) along with geothermal energy. This trigeneration system consists of a ground source heat pump, solar system, high-grade and low-grade heat exchangers, a heat pump system, and a water storage tank (WST). The objective of this system is to provide the main commodities for residential use including domestic hot water (DHW), electricity, and space heating. The system is analyzed energetically and exergetically using thermodynamic-based concepts. The overall energy and exergy efficiencies of the proposed system are found to be 86.9% and 74.7%, respectively. In addition, the energy and exergy efficiencies of the PVT system are obtained to be 57.91% and 34.19%, respectively. The exergy destructions at the high-grade heat exchanger and the water storage tank add up to 36.9 kW, which makes up 80% of the total exergy destruction of the system. Additionally, parametric studies are conducted to evaluate the degree of impact that various important parameters have on the overall system performance.

Experimental and Theoretical Investigation of Mixed and Stratified Hot Water Storage Tanks

1988 ◽  
Vol 202 (3) ◽  
pp. 187-193 ◽  
Author(s):  
P P Votsis ◽  
S A Tassou ◽  
D R Wilson ◽  
C J Marquand
Keyword(s):  
Heat Pump ◽  
Storage Tank ◽  
Dynamic Models ◽  
Water Storage ◽  
Pump Energy ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Water Storage Tank ◽  
Major Factors

This paper investigates the performance of a 1.1 m3 stratified hot water storage tank coupled to a vapour compression heat pump system. A comprehensive data acquisition system has been used to obtain the experimental data from a series of static and dynamic tests. In the static experiments a well-defined thermocline has been achieved and the effects of insulation and tank wall thickness on the preservation of the thermocline have been determined. The results indicate that thermal losses in stratified tanks are about 22 per cent higher than the losses in fully mixed tanks. The dynamic experiments have been conducted with an upward-moving thermocline and the major factors influencing its stability have been correlated in terms of the Archimedes number (Gr/Re2). It has been found that good stratification performance can be maintained with Archimedes numbers in the range between 35000 and 55000. A simplified one-dimensional model of the storage tank has been developed and validated against experimental results. The model will be linked to dynamic models of the heat pump and the building to simulate the performance of a heat store/heat pump energy management system.

Simulation Optimization and Experiment of R1234-ze on the Heat Pump Water Heater Storage Tank

2014 ◽  
Vol 1051 ◽  
pp. 828-831 ◽  
Author(s):  
Yan Qu ◽  
Fang Wang ◽  
Yu Wang ◽  
Peng Wang ◽  
Tang Li ◽  
...  
Keyword(s):  
Heat Pump ◽  
Storage Tank ◽  
Simulation Optimization ◽  
Water Storage ◽  
System Operation ◽  
Water Heater ◽  
Water Storage Tank ◽  
Heat Pump Water Heater ◽  
Fluent Software ◽  
The Stability

Using fluent software simulations to analysis the temperature field and the velocity field of the equal and changing diameter condensing coils at different positions of heat pump water storage tank, and made experiment of R1234-ze on the heat pump water heater storage tank with equal and changing diameter condensing coils ,experimental analysis and simulation results show that changing diameter condensing coils make the tank temperature raise stability, which is beneficial to the stability of the system operation.

Heat transfer effect on optimal performance of two-stage thermoelectric heat pumps

2007 ◽  
Vol 221 (12) ◽  
pp. 1635-1641 ◽  
Author(s):  
L Chen ◽  
J Li ◽  
F Sun
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Analytical Formula ◽  
Electrical Current ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Two Stage ◽  
Thermo Electric ◽  
Heating Load ◽  
Thermoelectric Heat

A model of two-stage semiconductor thermoelectric heat pumps with external heat transfer and internal irreversibility is built. Performance of the heat pump with Newton's heat transfer law is analysed and optimized using the combination of finite-time thermodynamics and non-equilibrium thermodynamics. The analytical formula about heating load versus working electrical current, and the coefficient of performance (COP) versus working electrical current are derived. For the fixed total number of thermoelectric elements, the ratio of number of thermo-electric elements of top stage to the total number of thermoelectric elements is also optimized for maximizing the heating load and the COP of the thermoelectric heat pump. The effects of design factors on the performance are analysed.

scholarly journals Heat consumption scenarios in the rural residential sector: the potential of heat pump-based demand-side management for sustainable heating

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
José Campos ◽  
Csaba Csontos ◽  
Ádám Harmat ◽  
Gábor Csüllög ◽  
Béla Munkácsy
Keyword(s):  
Energy Consumption ◽  
Storage Tank ◽  
Water Storage ◽  
Heat Pumps ◽  
Hot Water ◽  
Demand Side ◽  
Water Storage Tank ◽  
Energy Retrofit ◽  
Residential Heating ◽  
Heating Energy Consumption

Abstract Background Poor air quality and inadequate domestic heating sources are tightly connected problems in the Eastern-European countryside. There are a few alternatives to comprehensively solve these problems with an emphasis on economic and environmental sustainability. In this paper, individual heat pumps and energy efficiency measures are analyzed in four scenarios to investigate their role for cleaner and sufficient heating in rural settings. From a high-level perspective, this paper assesses the potential for electricity demand flexibility based on the use of individual heat pumps equipped with hot water storage. Methods In a first step, the current annual residential heating energy consumption of a rural area in Hungary is estimated with a bottom-up model using data from field surveys and official datasets. In a second step, four scenarios estimate the future heating energy consumption considering demographic trends and the average number of building retrofits (thermal insulation) performed yearly in the region. Results The reference scenario is a 20-year projection of heating energy consumption with modest retrofit actions which resulted in small energy savings. Alternative scenarios based on more effective retrofit actions reaching higher rates of the building stock would result in a 23–69% reduction in final energy consumption. Phasing out lignite from the heating energy mix would reduce particulate matter emissions. Each well-insulated dwelling with a heat pump-based system and hot water storage tank could provide theoretical flexibility of approximately 3.4 kWh per 24 h. Conclusions The current energy retrofit practices are not sufficient to solve the challenges faced in this area. Demand-side management policies based on the widespread use of individual heat pumps are an alternative to promote access to cleaner residential heating. An additional benefit is the potential for flexibility in electricity demand. Thus, this paper calls for an integration of energy retrofit with efficient heating (including hot water storage tank) to achieve results that further contribute to a future of sustainable energy.

scholarly journals Thermal Management of Hybrid Photovoltaic Systems

2021 ◽  
Vol 945 (1) ◽  
pp. 012050
Author(s):  
Jonathan Yong Kai Yeang ◽  
Rubina Baharand ◽  
Ooi Jong Boon
Keyword(s):  
Solar Irradiance ◽  
Storage Tank ◽  
Water Channel ◽  
Water Storage ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Fixed Cost ◽  
Water Storage Tank ◽  
Space Cooling ◽  
One Year

Abstract Photovoltaic cells can be quite sensitive to the change in temperature, as the entire system’s performance will be affected mainly by an increase in temperature. This is due to the degradation occurring in the solar panel when heat is absorbed, thus producing lesser electricity with the same amount of solar irradiance absorbed. Wind can provide additional cooling on the system; it is too unreliable to consider since wind can come unpredictably. For the design proposed, heat generated is carried away via the water channel underneath each collector’s glass panel. In order to utilize the removed heat, two subsystems are combined to the solar thermal collector. The primary subsystem uses heat to raise the temperature of the hot water storage tank. It can be further heated to the required temperature for the hot water used in the shower. The secondary subsystem consists of an absorption refrigeration system that will provide additional space cooling circulating the house. Based on the available data for maximum solar irradiance, the hot water storage tank can deliver up to 43.8 °C. Additional power of 2.28 kWh is required to raise the temperature to 50 °C. For space cooling, a coefficient of performance of about 2.2 is obtained at maximum solar irradiance. A breakeven point is also estimated to be approximately one year, even though the initial fixed cost for the system is way higher than the installation of conventional products.

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