Heat Pump Using a Solar Collector With Photovoltaic Modules on the Surface

1997 ◽  
Vol 119 (2) ◽  
pp. 147-151 ◽  
Author(s):  
Sadasuke Ito ◽  
Nakatsu Miura ◽  
Jin Qi Wang ◽  
Miwako Nishikawa
Keyword(s):  
Electric Power ◽  
Heat Pump ◽  
Convective Heat Transfer Coefficient ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Photovoltaic Modules ◽  
Photovoltaic Array ◽  
Hot Water Supply

It is known that the higher the evaporation temperature, the higher the coefficient of performance of a heat pump for hot water supply. Flat-plate solar collectors which were insulated on the back and bonded with flexible polycrystalline silicon-type photovoltaic modules on the upper surfaces were used in a heat pump system as the evaporator in order to increase the coefficient of performance and to generate electric power. The total area of the collectors was 3.24 m2 and the photovoltaic modules covered 76 percent of the area. The characteristics of the photovoltaic array and the thermal performance of the heat pump were studied experimentally. The results indicated that a coefficient of performance (COP) of the heat pump as high as six could be obtained at 40°C of the water temperature at the inlet of the condenser in the daytime in winter. The peak electric power generated was 120 W. It was found that the photovoltaic modules on the collectors did not influence the performance of the heat pump appreciably. When there was little solar radiation, the COP of the heat pump became two which was very low. This defect was improved by using an evaporator, which had a high convective heat transfer coefficient, arranged in parallel with the fiat-plate collectors.

Experimental Study of Heating-Cooling Combined Ground Source Heat Pump System with Horizontal Ground Heat Exchanger

2011 ◽  
Vol 374-377 ◽  
pp. 398-404 ◽  
Author(s):  
Ying Ning Hu ◽  
Ban Jun Peng ◽  
Shan Shan Hu ◽  
Jun Lin
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Pump ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Ground Heat Exchanger ◽  
Pipe Length ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling

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.

Analysis of Single-Phase Convective Heat Transfer and System COP at Higher Power Levels in Thermoelectric-Based Hydronic Cooling and Heating Device

2009 ◽  
Author(s):  
Michael J. Kazmierczak ◽  
Abhishek Gupta
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Flow Rate ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
System Component ◽  
Pump System ◽  
Heat Pump System ◽  
Higher Power ◽  
Te Modules

Experiments were performed on a heat exchanger equipped with multiple thermoelectric (TE) modules. The TE-HX serves as the basic system component in a simple hydronic modular Peltier heat pump system designed to provide chilled or hot water for domestic use (or supplementary building climate control) of small residences [1]. The present work focuses on the detailed convection analysis inside the TE-HX component when 10 thermoelectric modules are utilized. The local heat transfer coefficient at different points along the channel are measured at steady-state, first, when a continuous heater is installed and then when replaced with 10 TE modules. The experimental heat transfer coefficients obtained are compared with available empirical correlations for “transition” (3000 < ReDh < 7000) turbulent flow inside the channel with fair-to-good results. Next, the resulting coefficient-of-performance of the TE heat pump system is measured with its value depending both on system input power and water flow rate. Testing showed that performance degradation, i.e. reduced COPs, occurred when operated at higher power levels but remains satisfactory for up to 688 Watts with higher flow rate.

Effective Utilization System of Unused Energy in Aquarium

2003 ◽  
Author(s):  
Satoru Okamoto
Keyword(s):  
Heat Source ◽  
Electric Power ◽  
Latent Heat ◽  
Heat Pump ◽  
Heat Storage ◽  
Coefficient Of Performance ◽  
Latent Heat Storage ◽  
Pump System ◽  
Heat Pump System ◽  
Power Load

This paper introduces a heat pump system with a latent heat storage utilization seawater installed in an aquarium. For heating purpose such as air conditioning in order to maintain the indoor conditions at constant temperature and constant relative humidity, and cooling water supply to the fish tank in the aquarium, heat from seawater is collected as the heat source for the heat pump system. With regard to the heat pump system using low-temperature unutilized heat source, development is introduced on a heat source load responsive heat pump system, with combines a load variation responsive heat pump utilizing seawater with a latent heat (ice plus water slurry) storage system using nighttime electric power serving for electric power load leveling. The experimental COP (Coefficient of performance) of the proposed heat exchanger from seawater and latent heat storage cooling assisted heat pump system will be shown in detail.

Simulative Study on Solar-Assisted Air Source Heat Pump System

2013 ◽  
Vol 671-674 ◽  
pp. 2141-2144 ◽  
Author(s):  
Qiang Wang ◽  
Feng Zhen Liu ◽  
Li Jun Hou ◽  
Jian Hua Gao
Keyword(s):  
Heat Pump ◽  
Operating Conditions ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Pump Unit ◽  
Pump System ◽  
Heat Pump System ◽  
Air Source Heat Pump ◽  
Heat Pump Unit ◽  
The Stability

A solar assisted air source heat pump unit is designed. The mathematical model of the unit is established and two hybrid operating conditions of the system are simulated. The simulative studying results shows that in winter the solar assisted air source heat pump unit can make full use of solar energy and the coefficient of performance (COP) of air source heat pump can be improved. In summer the cooling heat of air source heat pump could be recovered to improve the stability of solar hot water collector and the COP of the air source heat pump unit is greatly improved. The performance of solar assisted air source heat pump unit is better than that of with no solar assisted air source heat pump.

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
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Water System ◽  
Heat Pumps ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Artificial Lighting ◽  
Hot Air ◽  
Marketable Fruit

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.

Performance Characteristics of a Combined Ejector-Absorption Heat Pump Using NH3-H2O

1999 ◽  
Author(s):  
D. A. Kouremenos ◽  
E. D. Rogdakis ◽  
G. K. Alexis
Keyword(s):  
Heat Pump ◽  
Gain Factor ◽  
Coefficient Of Performance ◽  
Detailed Calculation ◽  
Absorption System ◽  
Evaporator Temperature ◽  
Pump System ◽  
Heat Gain ◽  
Absorption Heat Pump ◽  
Heat Pump System

Abstract Absorption system have been investigated for many years. However, coefficient of performance COP or heat gain factor HGF for absorption systems are significantly lower than those for conventional compression systems. This has restricted their wide application. This paper discusses the behavior of mixture NH3-H2O through of an ejector, operating in an absorption heat pump system. This combination improves the performance of conventional absorption system and with the phasing out of ozone-damaging refrigerants, absorption refrigerators, heat pumps and air-conditioning now provide a potential alternative. For the detailed calculation of the proposed system a method has been developed, which employs analytical functions describing the thermodynamic properties of die mixture. The influence of three major parameters: generator, condenser and evaporator temperature, on ejector efficiency and heat gain factor of the system is discussed. Also the maximum value of HGF was estimated by correlation of above three temperatures.

Modeling of a Smart Heat Pump Made of Laminated Thermoelectric and Electrocaloric Materials

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Dudong Feng ◽  
Shi-Chune Yao ◽  
Tian Zhang ◽  
Qiming Zhang
Keyword(s):  
Heat Pump ◽  
Temperature Difference ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Laminated Structure ◽  
Heat Pump System ◽  
Simple Arrangement ◽  
Parametric Effects ◽  
Hybrid Heat Pump ◽  
Physical Features

In this study, a smart heat pump, which could be used for the cooling of electronics, made of laminated structure of thermoelectric (TE) and electrocaloric (EC) materials, is studied. A simple arrangement of two TE layers sandwiched with one EC layer is modeled. This smart heat pump utilized the newly developed EC materials of giant adiabatic temperature change and the TE materials of high figure of merit. The system has the advantages of no moving parts, made of solid state, operable over large working temperature difference, and can be formed into very small size. The operation of the device is numerically modeled considering the three major parametric effects: EC operation as a function of time, electric current applied on TE, and temperature difference between the hot and cold sinks. The results on coefficient of performance (COP) and heat flow per unit area are discussed. This study is performed as an early attempt of analyzing the basic physical features of TE–EC–TE laminated structure heat pump and extends the understanding by further discussing the tradeoff between lower COP and larger overall temperature difference coverage in the TE/EC hybrid heat pump system with multilaminated structure.

scholarly journals Theoretical Analysis of a Single-Stage Gas-fired Ejector Heat Pump Water Heater

2021 ◽  
pp. 1-28
Author(s):  
Jeremy Spitzenberger ◽  
Pengtao Wang ◽  
Laith Ismael ◽  
Hongbin Ma ◽  
Ahmad Abuheiba ◽  
...  
Keyword(s):  
Heat Pump ◽  
Thermal Energy ◽  
Ambient Air ◽  
Single Stage ◽  
Coefficient Of Performance ◽  
Water Heater ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Capacity ◽  
Condenser Temperature

Abstract Ejector driven systems have the ability to operate at high efficiencies, utilizing recycled thermal energy as a power source. For a typical ejector heat pump system, the increase of the condenser temperature reduces the coefficient of performance (COP). In addition, if the condenser temperature is higher than the critical temperature, the ejector may not function. In this situation, the condenser temperature must be reduced, and an additional heater will be utilized to heat the production water from the condenser temperature to the desired temperature. In this investigation, a single-stage gas-fired ejector heat pump (EHP) is investigated and thermodynamically modeled in order to optimize the system COP for the purpose of heating water by utilizing the thermal energy from the ambient air. The effects of the high-temperature evaporator (HTE) and low-temperature evaporator (LTE) temperatures on the ejector critical back pressure and the EHP system performance are examined for a HTE temperature range of 120-180 °C and LTE temperatures of 15.5, 17.5, and 19.5 °C. Results show that an optimized COP of the EHP system exists which depends on HTE and LTE temperatures, primary nozzle throat diameters. In addition, it is found that the EHP COP is independent of the ejector COP. From this investigation a maximum EHP COP of 1.31 is able to be achieved for a HTE temperature of 160 °C and a LTE temperature of 19.5 °C with a total heating capacity of 15.98 kW.

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