scholarly journals Guideline for Electricity Generation from Hot Springs (Natural Energy Storage Systems): A Techno-enviro-economic Assessment

2021 ◽  
Author(s):  
Saeed Ghoddousi ◽  
Behnaz Rezaie ◽  
Samane Ghandehariun
Keyword(s):  
Power Generation ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Hot Springs ◽  
Hot Spring ◽  
Water Discharge ◽  
Hot Water ◽  
Specific Investment ◽  
Generation Capacity

The scattered hot springs on the globe are natural thermal energy storages that are available for industrial and recreational advantages. A hot spring is a hydrothermal system that can be used for power generation purposes as well as deep-well geothermal plants. In the present study, a techno-enviro-economic study is conducted to determine the power generation potential of hot springs as a heat source of the Organic Rankine Cycle (ORC). The hot water temperature and discharge mass flow rate from hot springs varies from 60 to 90 ᵒC and 5 to 50 kg/s, respectively. The ORC plant is modeled by Aspen Plus V9. The impacts of the temperature and mass flow rate of discharge from hot springs on the thermodynamics and economics of the plants are investigated. The results indicate that increasing the hot spring temperature and discharge mass flow rate improves the thermal efficiency and power generation capacity of ORC plant while Payback Period (PP), Levelized Energy Cost (LEC), and Specific Investment Cost (SIC) shrink. The power generation capacity varies from 9.3 kW to 303 kW and the LEC range is from 0.03 $/kWh to 0.13 $/kWh based on the hot spring and water discharge mass flow rate.

scholarly journals Thermal Characteristics Analysis on Multi- Heat Pipe Induced Heat Exchanger

2019 ◽  
Vol 9 (2S2) ◽  
pp. 143-147 ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Pipe ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cold Water ◽  
Hot Water ◽  
Working Fluid ◽  
Physical Parameters

In this investigation of multi heat pipe induced in heat exchanger shows the developments in heat transfer is to improve the efficiency of heat exchangers. Water is used as a heat transfer fluid and acetone is used as a working fluid. Rotameter is set to measure the flow rate of cold water and hot water. To maintain the parameter as experimental setup. Then set the mass flow rate of hot water as 40 LPH, 60LPH, 80 LPH, 100LPH, 120 LPH and mass flow rate of cold water as 20 LPH, 30 LPH, 40 LPH, 50 LPH, and 60 LPH. Then 40 C, 45 ºC, 50 ºC, 55 C, 60 ºC are the temperatures of hot water at inlet are maintained. To find some various physical parameters of Qc , hc , Re ,, Pr , Rth. The maximum effectiveness of the investigation obtained from condition of Thi 60 C, Tci 32 C and 100 LPH mhi, 60 LPH mci the maximum effectiveness attained as 57.25. Then the mhi as 100 LPH, mci as 60 LPH and Thi at 40 C as 37.6%. It shows the effectiveness get increased about 34.3 to the maximum conditions.

scholarly journals Heat loss from hot water flowing in a copper pipe insulated using air enclosed with a PVC pipe

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
A. Albayani ◽  
M. Mirmanto ◽  
S. Syahrul
Keyword(s):  
Mass Flow Rate ◽  
Heat Loss ◽  
Mass Flow ◽  
Flow Rate ◽  
Test Section ◽  
Hot Water ◽  
Fluid Temperature ◽  
Copper Pipe ◽  
Pvc Pipe ◽  
Bare Copper

This paper presents investigations of heat loss from hot water flowing in an insulated copper pipe. Investigations were performed to know the heat loss from a copper pipe insulated using air enclosed with a PVC pipe. The fluid temperature used was kept at approximately 75°C in the entrance and its mass flow rate was around 12 g/s. The nominal copper pipe diameter was 6.35 mm; while the diameters of the PVC pipe were ranging from 12.7 mm to 5.08 mm. The length of the test section was approximately 3000 mm. The results show that the biggest heat loss is found using the bare copper pipe. When the copper pipe is insulated using air enclosed with a PVC pipe, the heat loss decreases with the increased PVC pipe diameters. The trend of the heat loss agrees with the critical insulation diameter theory.

Experimental Study on a New Small-Scale Absorption System: Response Surface and Inverse Analyses

2021 ◽  
pp. 1-41
Author(s):  
Gaurav Singh ◽  
Ranjan Das
Keyword(s):  
Response Surface ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Load ◽  
Driving Factors ◽  
Hot Water ◽  
Small Scale ◽  
Absorption System ◽  
Multi Objective

Abstract In this paper, a new small-scale lithium bromide (LiBr)-water absorption system consisting water-cooled evaporator and air-cooled condenser is experimentally studied. For compactness, water-cooled heat exchangers for evaporator, absorber and generator are made helical-coiled type, whereas, based on the water availability and load requirements, condenser is air-cooled. Accurate empirical correlations for thermal load and evaporator temperature against system driving factors concerning a have been reported. Thereafter, response surface analysis of the developed performance parameters are studied with respect to LiBr concentration, temperature of generator and mass flow rate of hot water. Using experimental data, estimation of overall heat transfer coefficient (U) and its variation with system driving factors is quantified. The error margin between theoretical and actual pressure loss is limited within 5 %. Next, a multi-objective inverse analysis of the developed system is done to simultaneously retrieve the required LiBr concentration, mass flow rate of hot water, and vapor generator temperature to derive a desired cooling performance demand from the system. The obtained U values for all the components are found to be in line with the standard data. The physics related to salt concentration and generator temperature in governing U values are reported. Apart from the developed correlations, it can be established that the necessary operational parameters can be predicted by the present multi-objective inverse method to meet the necessary thermal load and temperature demands within an accuracy level of 6 % and 5 %, respectively.

Performance Analysis of the Low-Temperature Solar-Boosted Power Generation System—Part I: Comparison Between Kalina Solar System and Rankine Solar System

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Faming Sun ◽  
Yasuyuki Ikegami ◽  
Hirofumi Arima ◽  
Weisheng Zhou
Keyword(s):  
Power Generation ◽  
Solar System ◽  
Low Temperature ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Solar Collector ◽  
Operating Conditions ◽  
Kalina Cycle ◽  
Solar Systems

On the base of the two classical thermodynamic cycles (Kalina cycle and Rankine cycle), solar-boosted Kalina system (Kalina solar system) and solar-boosted Rankine system (Rankine solar system) with traditional nonconcentrating flat plate solar collector (FPSC) and evacuated tube solar collector (ETSC) are investigated in the present paper. The proposed solar systems are considered to be the hybrid of power generation subcycle and solar collector subcycle. Their electricity generating performances are compared under their respective optimal operating conditions to clarify which one is more competitive in solar utilization. Results show that ETSC is the better choice for the both solar systems. Further, the performance comparison shows that the low-temperature solar energy utilized in Kalina cycle is predominant to generate electricity. Meanwhile, the study also find that mass flow rate of the power generation subcycle, mass flow rate of the solar collector subcycle, mass fraction of ammonia and the regenerator performance are important operational parameters for high performance of the Kalina solar system. Finally, with the aid of the weather conditions of Kumejima Island in Japan, the perceptual knowledge for Kalina solar system by using an application case is shown in the paper.

scholarly journals Heat loss from hot water flowing in a copper pipe insulated using air enclosed with a PVC pipe

2018 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
A. Albayani ◽  
M. Mirmanto ◽  
S. Syahrul
Keyword(s):  
Mass Flow Rate ◽  
Heat Loss ◽  
Mass Flow ◽  
Flow Rate ◽  
Test Section ◽  
Hot Water ◽  
Fluid Temperature ◽  
Copper Pipe ◽  
Pvc Pipe ◽  
Bare Copper

This paper presents investigations of heat loss from hot water flowing in an insulated copper pipe. Investigations were performed to know the heat loss from a copper pipe insulated using air enclosed with a PVC pipe. The fluid temperature used was kept at approximately 75°C in the entrance and its mass flow rate was around 12 g/s. The nominal copper pipe diameter was 6.35 mm; while the diameters of the PVC pipe were ranging from 12.7 mm to 5.08 mm. The length of the test section was approximately 3000 mm. The results show that the biggest heat loss is found using the bare copper pipe. When the copper pipe is insulated using air enclosed with a PVC pipe, the heat loss decreases with the increased PVC pipe diameters. The trend of the heat loss agrees with the critical insulation diameter theory.

scholarly journals Experimental Study of a Concentric Tube Heat Exchanger with Helical Baffle Using CFD

2021 ◽  
Vol 1 (1) ◽  
pp. 32-38
Author(s):  
Jithendra Sai Raja Jithendra Sai RajaChada ◽  
◽  
Akhil Yuvaraj Manda ◽  
Venkat Sandeep Gadi ◽  
Ramasamy Dharmalingam ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Hot Water ◽  
External Diameter ◽  
Tube Heat Exchanger ◽  
Different Temperatures ◽  
Helical Baffle ◽  
Optimum Model

Heat exchangers are the most common equipment used to transfer heat from high-temperature fluid to low-temperature fluid without direct contact. The present study considers the analytical approach on a concentric tube heat exchanger with the helical baffle. The objective of the study is to reduce the size with effect to increase the effectiveness of the heat exchanger. A heat exchanger with 100 mm external diameter and 560 mm length contains a helical baffle with 20 degrees inclination. The designed heat exchanger is analysed by varying the mass flow rate of hot water from 0.25 Kg/s to 2 Kg/s at an interval of 0.25 kg/s at three different temperatures i.e. 363.16 K, 368.16 K, 373.16 K. A nanofluid is applied to cool the hot water without any loss. The mass flow rate of cold fluid is 2 Kg/s at 30 degrees Celsius. The results have displayed that the heat exchanger exhibited appreciable effectiveness at a flow rate of 0.25 Kg/s for hot water at 373.16 K temperature. There by suggesting it as the optimum model of the heat exchanger.

Scaling Effect of Direct Solar Hot Water Systems on Energy Efficiency

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
U. C. Arunachala ◽  
M. Siddhartha Bhatt ◽  
L. K. Sreepathi
Keyword(s):  
Heat Transfer ◽  
Energy Efficiency ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Transfer Rate ◽  
Water Systems ◽  
Hot Water ◽  
Forced Circulation ◽  
Scale Thickness

Scale formation in risers and header of direct solar hot water systems is a problem in places where hard water is being used. In this paper, the effect of scaling on energy efficiency indices such as instantaneous efficiency, mass flow rate, and overall heat loss coefficient are quantified by Hottel–Whillier–Bliss equation in the case of thermosiphon and forced circulation systems. The effect of scaling on mass flow and heat transfer rate for both the systems are quantified with experimental validation. Experimentally found mass flow rate is 50% of the analytical mass flow rate for a clean riser and agrees 99% for the case of riser with 3.75 mm scale thickness. This is due to the extreme change in pressure gain in the narrow region. Scale mapping is done for the entire solar hot water system to study the nature of scale growth. The complete footer and nine risers for the length of 150 mm from footer are free from scaling in axial and radial direction. This is due to the low water temperature in the region. The major portion of header and risers for the length 180 mm from the header are completely blocked due to maximum temperature of water in that region. A scale prediction model is brought out based on the experimentally observed scaled water heaters in the field. It reveals that the major parameters to be considered for the correlation are water total hardness and calcium hardness. It is seen in the thermosiphon system that the mass flow rate decreased by scaling affects energy efficiency more than that caused by the heat transfer rate. The scaling effect is more predominant in thermosiphon systems than in forced circulation systems. The analytical study reveals a drop in instantaneous efficiency of 39.5% in thermosiphon system and 7.0% in the case of forced circulation system for the scale thickness of 3.75 mm. The difference between mass flow rate in scaled and unscaled condition is less in forced circulation but much higher in thermosiphon system.

Fluid Flow Control in Domestic Hot Water Systems During Days with Different Radiative Stability Levels

2018 ◽  
Vol 60 (1) ◽  
pp. 88-96
Author(s):  
Sanda Budea ◽  
Viorel Badescu
Keyword(s):  
Heat Flux ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Storage Tank ◽  
Meteorological Data ◽  
Thermal Conversion ◽  
Hot Water ◽  
Primary Circuit ◽  
Fluid Flow Control

AbstractThis paper presents models/strategies for optimum performance of solar collector in closed loop systems. These models aim to maximize the obtained energy by thermal conversion of solar energy. The mass flow rate of the fluid from the primary circuit of the system is the control parameter. The semi empirical models and optimal control methods are in brief presented. The volume of the storage tank is important and the ratio Vs/Ac between this volume and area of the collectors is a key factor in appropriate sizing of the DHW system. Therefore, the paper establishes a relationship between this ratio and the mass flow rate of the fluid in the collector This paper also analyses the variation of the energetic performance (useful heat flux transferred to the storage tank, heat flux transferred to the water, water temperature in the storage tank) with the volume of the storage tank. Analysis was performed on an extensive set of meteorological data from Timisoara, Romania, with instantaneous data (measured at 15 seconds) for summer days, from July 2009, with different relative sunshine values, σ. Important differences have been observed between days with different stability levels - days more or less stable.

scholarly journals A Study on the Heat Transfer Rate Performance of the Hot Water Circulating in the Tubes in the Hot Water Panels Laid in the Walls and Floor of a Small Leisure Cabin in Relation to Changes in the Temperature and Flow Rate of the Hot Water

2021 ◽  
Vol 58 (1) ◽  
pp. 3468-3476
Author(s):  
Dong-Hyun Cho
Keyword(s):  
Heat Transfer ◽  
Mass Flow Rate ◽  
Heat Transfer Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Energy ◽  
Transfer Rate ◽  
Hot Water ◽  
Radiant Heat Transfer ◽  
Rate Performance

In this study, hot water panels were laid in the three walls as well as the floor of a small leisure cabin to implement radiant heating with the heat supplied by the hot water circulating inside the hot water tubes in the hot water panels. As a result of the study as such, compared to the forced convection heating at the current technology level in which air is forced to circulate by the air conditioner, the radiant heat transfer by the hot water panels laid in the floor and walls of the small leisure cabin in this study implemented more comfortable heating and wellbeing heating beneficial to health because it implemented heating without any movement or circulation of air. In addition, this study investigated heater accessories suitable for small leisure cabins not larger than 6 m2 to significantly reduce thermal energy and manufacturing costs. The thermal energy lost by hot water per unit time and the thermal energy obtained by air inside the small leisure cabin per unit time coincided well at the accuracy of ±5%. Therefore, the reliability of the result of the heat transfer rate accuracy experiment in this study was secured. As the mass flow rate of the hot water increased, the heat transfer rate performance of the small leisure cabin improved. In addition, as the mass flow rate of hot water increased, the heat transfer rate performance of the small leisure cabin improved linearly.

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