scholarly journals Cooling Performance Assessment of a Slinky Closed Loop Lake Water Heat Pump System under the Climate Conditions of Pakistan

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 553 ◽  
Author(s):  
Muhammad Kashif Shahzad ◽  
Mirza Abdullah Rehan ◽  
Muzaffar Ali ◽  
Azeem Mustafa ◽  
Zafar Abbas ◽  
...  
Keyword(s):  
Water Temperature ◽  
Heat Pump ◽  
Lake Water ◽  
Closed Loop ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Experimental Setup ◽  
Pump System ◽  
Climate Conditions ◽  
Heat Pump System

This paper presents an experimental evaluation of a closed loop lake water heat pump (LWHPs) system based on the slinky coiled configuration. Initially, a mathematical model is developed in the Engineering Equation Solver (EES) for the heat pump system and the submerged coils in a lake. System performance is determined for the submerged slinky copper coils under the various operating conditions. Afterwards, parametric analysis is performed considering different influencing parameters, such as the lake water temperature, ambient temperature, and mass flow rate of the circulating fluid at constant lake depth of 4 ft. The experimental setup is developed for 3.51 kW cooling capacity after cooling load calculation for a small room. In the current study, slinky copper coils are used to exchange heat with lake water. The experimental setup is installed in Taxila, Pakistan, and the system’s performance is analyzed during selected days. After experimentation based on hourly and daily operation characteristics, it is observed that the lake water temperature has significant influence on the heat transfer rate between slinky coil and lake water. While the lake water temperature in summer decreases and increases in winter with the depth. The resulted daily average coefficient of performance (COP) of the system is within the range of 3.24–3.46 during the selected days of cooling season. Based on these results, it can be concluded that the LWHP systems can be considered a viable solution for Pakistan having a well-established canal system.

Experimental Study and Application Analysis on Ground-Water Source Heat Pump In North China

Solar Energy ◽  
2006 ◽  
Author(s):  
Zhun Yu ◽  
Youyin Jing ◽  
Yingbai Xie ◽  
Xutao Zhang
Keyword(s):  
Ground Water ◽  
Water Temperature ◽  
Heat Pump ◽  
Heat Load ◽  
North China ◽  
Water Source ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Water

To describe the economical performance and operational characteristic of ground-water source heat pump system (GWSHPS) in North China, GWSHPS was compared with traditional central air-conditioning system (TCACS) for their total investments based upon a GWSHPS demonstration project in Beijing (88000 m2 covered area, 4572 kW heat exchange amount). At the same period, an experimental system of GWSHPS in Hebei was investigated with its operational data such as coefficient of performance (COP). The results of the demonstration project showed that the total investment for GWSHPS was 15.2% lower than TCACS, while annual operating cost for GWSHPS was 42.2% lower than TCACS. The test data of the system in Hebei showed that heating coefficient of performance of the heat pump and primary energy ratio (PER) were raised while heating water temperature was decreased. The entering water temperature to the unit ranged from 13.1°C to 17.4°C, with an average value of 15 °C, the heating water temperature varied from 40°C to 50°C, with the standard work condition of 45°C. The COPHP was about 4.12 at the minimum of heating water temperature, while it was about 3.47 at the maximum of heating water temperature and fluctuated between these values in other temperature. The results of the present work implies that GWSHPS is favorable for North China. However, buildings in North China have high heat load in winter, consequently, GWSHPS designed upon heat load will cause a waste in summer, thus, the solar-assisted ground-water source heat pump system (SAGWSHPS) which combines heat pump with solar water heater can be suggested as the best solution in North China.

A Comparative Study on Long-Term Energy Efficiency of Two Kinds of Ground-Source Heat Pump Systems

2014 ◽  
Vol 1070-1072 ◽  
pp. 349-352
Author(s):  
Fei Lei ◽  
Ping Fang Hu
Keyword(s):  
Water Temperature ◽  
Heat Pump ◽  
Coefficient Of Performance ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
Groundwater Heat Pump ◽  
Term Energy ◽  
Electrical Consumption

The energy efficiencies of two kinds of ground-source heat pump systems (GSHPs) are evaluated in this study based on field data. The two kinds of GSHPs are a ground-coupled heat pump system (GCHPs) and a groundwater heat pump system (GWHPs) which were installed in two apartment buildings of wuhan, respectively. We monitored various operating parameters, including the outdoor temperature, the flow rate, the electrical consumption and the water temperature. The values of coefficient of performance (COP) of system and chiller were evaluated based on a series of measurements. The seasonal COP of the chillers of the GCHPs and the GSHPs were 4.45 and 3.94 in the cooling season, 5.07 and 3.69 in the heating season. The comparison of COP implies that the GWHPs is more efficient than the GCHPs due to its steady water temperature of ground source heat exchanger.

scholarly journals Numerical Simulations on the Application of a Closed-Loop Lake Water Heat Pump System in the Lake Soyang, Korea

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 762
Author(s):  
Dong Kyu Park ◽  
Youngmin Lee
Keyword(s):  
Renewable Energy ◽  
Heat Pump ◽  
Lake Water ◽  
Closed Loop ◽  
Pump System ◽  
Efficient Operation ◽  
Carrier Fluid ◽  
Heat Pump System ◽  
Operation Conditions ◽  
Helical Tubes

A lake is one of the geothermal energy sources to meet increasing demands for renewable energy use. In this study, a series of numerical modeling was performed to evaluate the applicability of a close-loop lake water heat pump (LWHP) system in Lake Soyang, Korea. A non-isothermal pipe flow model was used to simulate the flow and heat transfer processes occurring in the LWHP system with the main pipe and several helical tubes for heat exchange. Based on the temperature data measured in the Lake Soyang for 4 years, the installation depth and the number of helical tubes were determined sequentially, and the sensitivities of additional installation and operation factors on the system performance were analyzed. Assuming a mild current in the lake, the installation and operation conditions for the efficient operation of the system were suggested as follows: The installation of 16 helical tubes at 50 m deep, the circulation rates of heat-carrier fluid of 189.3 L/min, the inner diameter of tubes of 32 mm, and the wall thickness and thermal conductivity of 2.9 mm and 0.4 W/mK, respectively. Considering many lakes and reservoirs in Korea, the closed-loop LWHP system would be a viable renewable energy application.

scholarly journals Seasonal Performance Investigation for Residential Heat Pump System with Different Outdoor Heat Exchanger Designs

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4714
Author(s):  
Shehryar Ishaque ◽  
Man-Hoe Kim
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Cycle Performance ◽  
Tube Length ◽  
Pump System ◽  
Heat Pump System ◽  
Tube Heat Exchanger ◽  
Finned Tube Heat Exchanger

A finned tube heat exchanger is a key component used as a condenser or an evaporator in residential air-conditioning (AC) and heat pump systems. The overall cycle performance of these systems is significantly affected by the heat exchanger’s geometric design. This study investigates outdoor heat exchanger designs with varying geometric parameters such as the fin pitch, number of tube rows, and tube length, and their effect on system performance based on seasonal energy efficiency ratio (SEER) and seasonal coefficient of performance (SCOP). Air face velocity profiles for each operating condition along the outdoor heat exchangers are determined using CFD, with subsequent cycle simulations for 10 different operating conditions. Results have been validated with the available experimental data. The number of tube rows, fin pitch, and length of tube have been varied from 2–10, 1.4–2.5 mm, and 800–2800 mm respectively. The numerical results reveals that SEER increases 3.21% while SCOP increases 5.32% up to fourth and fifth tube row respectively and remain unaffected thereafter. Similarly, SEER increases by 3.55% as the tube length is increased from 800–1800 mm, while it increases only 0.67% for 1800–2800 mm and the maximum variation of 4.32% has been found for SCOP. Moreover, increasing the fin pitch reduces SEER and SCOP (except for fin pitch from 1.4 to 1.8 mm). Finally, the performance of the system with four different fin configurations have also been investigated and it has been found that slit fins are more effective.

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.

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.

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