scholarly journals A Waste Energy Recovery Management for Electricity Generation from Two Temperature Grades of Energy Sources in Subcritical Organic Rankine Systems

2021 ◽  
Vol 8 (3) ◽  
pp. 217-236
Author(s):  
Ali H. Tarrad
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Energy Management ◽  
Thermal Efficiency ◽  
Energy Recovery ◽  
Temperature Cycle ◽  
Compound System ◽  
Temperature Level ◽  
Evaporation And Condensation ◽  
Waste Energy

Waste energy represents one of the most critical issues for the economic utilization and management of energy in modern industrial fields. This article outlines a scheme to utilize two different source temperature levels within the envelope of higher than 200 °C zones. Two regenerative organic Rankine cycles (RORC) were implemented to construct a compound regenerative organic Rankine cycle (CRORC) to improve the energy management of the sources. These two mini-cycles were integrated throughout an intermediate economizer circuit to extract a certain amount of energy from the high-temperature level mini-cycle. R-123 was circulated in the high-temperature cycle due to its high critical temperature at evaporation and condensation temperatures of 160 °C and 50 °C, respectively. R-123, R-21, and hydrocarbon R-600 were used as working fluids for the low-temperature cycle at evaporation and condensation temperatures of 130 °C and 35 °C, respectively. The R-123 fluid in the high-temperature mini-cycle was superheated to 170-240 °C, whereas the fluid in the low-temperature level was superheated to 180 °C. The results showed that the independent system (IRORC) requires more energy recovery than the compound system by a maximum of 2% to achieve the same net power output. This corresponds to the enhancement of 2% for the system net thermal efficiency of the compound (CRORC) system compared to the independent (IRORC) one. The compound (CRORC) system revealed a net thermal efficiency in the range of 14% and 15.6% for the test conditions. The mini-cycle net thermal efficiency of the low-temperature in the compound system was enhanced by a range of 2.5-5% compared to that of the independent arrangement. R-123/R-123 and R-123/R-21 systems exhibited higher net thermal efficiencies than the R-123/R-600 one by 3% and 2%, respectively. Increasing the superheat degree of the high-temperature mini-cycle from 10 °C to 80 °C for the compound system has improved the thermal efficiency by 7.6-7.9% for the examined fluid pairs and operating conditions. Keywords: compound cycle, regenerative, energy management, energy recovery, organic fluids

scholarly journals A Perspective Evolution Methodology of Energy Management in a Subcritical Regenerative Organic Rankine Cycles Operate at Two Temperature Levels

2021 ◽  
Vol 8 (1) ◽  
pp. 9-26
Author(s):  
Ali H. Tarrad
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Energy Management ◽  
Thermal Efficiency ◽  
Energy Recovery ◽  
Operating Conditions ◽  
Temperature Cycle ◽  
Evaporation And Condensation ◽  
Organic Rankine Cycles ◽  
Temperature Levels

The waste energy recovery and management philosophy represent a great challenge for scientists. This article outlines a scheme to utilize two different source temperature levels in the range of (160–200) °C. Two regenerative organic Rankine cycles (RORC) were implemented to construct a compound regenerative organic Rankine cycle (CRORC) to improve the energy management of the sources. The method of energy management for these cycles was accomplished by extracting a certain amount of energy from the high-temperature cycle and rejecting it to the working fluid in an economizer at the low-temperature level. R-123 was circulated in the high-temperature cycle due to its high critical temperature at evaporation and condensation temperatures of 150 °C and 50 °C respectively. R-123, R-245fa, R-1233zd-E, and the hydrocarbon R-600a were used as working fluids for the low-temperature cycle at evaporation and condensation temperatures of 130 °C and 35 °C respectively. This technique showed that the first law of thermodynamics efficiency was augmented by (3–5)% for the low-temperature mini-cycle of the (CRORC). The energy consumption at the low-temperature cycle was also reduced by (3–5)%. The latter reduction range accounts for 2% for the total extracted energy for the independent system where both high-temperature and low-temperature cycles were utilized separately. The data showed that increasing the superheat degree from 10 °C to 20°C has enhanced the thermal efficiency of the compound (CRORC) system by (2–4)%. The (CRORC) system of R-123/R600a, R-123/R-123, and R-123/R-245fa fluid pairs exhibited higher thermal efficiency than that of R-123/R-1233zd-E pair by (4.5–6)%, (4–6)% and (3–4)% respectively. The net thermal efficiency of the compound (CRORC) system fell in the range (12–13)% and the low-temperature mini-cycle of the (CRORC) system had a range of (12–14)% for all of the examined operating conditions. Keywords: compound cycle, regenerative, energy management, energy recovery

Review Status on High Temperature Heat Pumps

2012 ◽  
Vol 170-173 ◽  
pp. 2550-2553 ◽  
Author(s):  
Guang Hui Zhou ◽  
Shi Wei Feng ◽  
Si Qi Cui ◽  
Yin Liu
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Heat Pump ◽  
Heat Pumps ◽  
Industrial Processes ◽  
Paper Briefly ◽  
Development Status ◽  
Temperature Heat ◽  
Waste Energy ◽  
Higher Temperature

A heat pump is a kind of energy saving equipment. It can effectively improve the grade of low temperature renewable and waste energy. Because of the increasing demands for higher temperature energy in many industrial processes and other fields, the development and research of high temperature heat pumps have been becoming more and more pressing and significant. This paper briefly summarizes the development status in two aspects: the development of working fluids and system features and characteristics of different cycle types.

Study on the Mechanical Property of Nomex Fiber in Different Temperature

2014 ◽  
Vol 887-888 ◽  
pp. 895-898
Author(s):  
Gen Yang Cao ◽  
Xing Fang Xiao ◽  
Wei Lin Xu
Keyword(s):  
Mechanical Property ◽  
High Temperature ◽  
Low Temperature ◽  
Temperature Cycle ◽  
High Tech ◽  
New Materials ◽  
Breaking Elongation ◽  
Temperature Conditions ◽  
World Today ◽  
The World

Nomex (Aramid 1313) is the best high temperature resistant high-tech new materials in the world today. In this paper, Nomex was treated in the experiment of high temperature, low temperature, high and low temperature conditions. The results show that the high temperature affects the strength and breaking elongation for nomex fiber. Low temperature and high & low temperature cycle does not affect much on the strength and breaking elongation.

Stress Intensity Factor of Thermal Fatigue Crack in High Temperature

2012 ◽  
Vol 581-582 ◽  
pp. 677-680
Author(s):  
Ming Yan ◽  
Hao Chuan Li ◽  
Lin Li
Keyword(s):  
Stress Intensity Factor ◽  
Fatigue Crack ◽  
High Temperature ◽  
Stress Intensity ◽  
Low Temperature ◽  
Intensity Factor ◽  
Thermal Fatigue ◽  
Kinematic Hardening ◽  
Temperature Cycle ◽  
Thermal Fatigue Crack

Stress intensity factor of thermal fatigue crack was calculated within one cycle by using finite element method in consideration of the multi-linear kinematic hardening characteristic of a material. The affection of loading sequence to stress intensity factor was studied under circularly variational temperature by comparing to that in one cycle. The low temperature cycle can not affect the stress intensity factor of latter cycles with high temperature; but high temperature cycle can affect the stress intensity factor of latter cycles with low temperature, and make it be equal to that of the high temperature cycle.

scholarly journals Experimental investigation of the ecological hybrid refrigeration cycle

2014 ◽  
Vol 35 (3) ◽  
pp. 145-154
Author(s):  
Piotr Cyklis ◽  
Ryszard Kantor ◽  
Tomasz Ryncarz ◽  
Bogusław Górski ◽  
Roman Duda
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Heat Source ◽  
Waste Heat ◽  
Temperature Limit ◽  
Working Fluid ◽  
Temperature Cycle ◽  
Compression System ◽  
High Temperature Limit ◽  
University Of Technology

Abstract The requirements for environmentally friendly refrigerants promote application of CO2 and water as working fluids. However there are two problems related to that, namely high temperature limit for CO2 in condenser due to the low critical temperature, and low temperature limit for water being the result of high triple point temperature. This can be avoided by application of the hybrid adsorption-compression system, where water is the working fluid in the adsorption high temperature cycle used to cool down the CO2 compression cycle condenser. The adsorption process is powered with a low temperature renewable heat source as solar collectors or other waste heat source. The refrigeration system integrating adsorption and compression system has been designed and constructed in the Laboratory of Thermodynamics and Thermal Machine Measurements of Cracow University of Technology. The heat source for adsorption system consists of 16 tube tulbular collectors. The CO2 compression low temperature cycle is based on two parallel compressors with frequency inverter. Energy efficiency and TEWI of this hybrid system is quite promising in comparison with the compression only systems.

Thermal Destruction of Microorganisms in Meat by Microwave and Conventional Cooking1

1977 ◽  
Vol 40 (7) ◽  
pp. 442-444 ◽  
Author(s):  
F. LEON CRESPO ◽  
H. W. OCKERMAN
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Thermal Destruction ◽  
Ground Beef ◽  
Internal Temperature ◽  
Temperature Level ◽  
Microwave Cooking ◽  
Microbial Destruction

When heating ground beef to internal temperatures of 34, 61, and 75 C, high temperature (232 ± 6 C) oven cooking was more effective for bacterial destruction than low temperature (149 ± 6 C) oven cooking. Low temperature oven cooking was more effective than microwave cooking. These differences in microbial destruction rates became significant (P<05) when the meat reached the 75-C internal temperature level.

Experimental Study on Two-Stage Cascade Low Temperature Pre-Cooling Equipment

2010 ◽  
Vol 42 ◽  
pp. 322-325
Author(s):  
Xiu Fang Liu ◽  
Fa Hui Wang ◽  
Fan Mao Meng
Keyword(s):  
Experimental Study ◽  
High Temperature ◽  
Low Temperature ◽  
Cooling Capacity ◽  
Temperature Cycle ◽  
Test Bed ◽  
Two Stage ◽  
Overload Protection ◽  
Set Up ◽  
Two Stages

A two-stage cascade pre-cooling test bed was designed and set up to develop a -30°C /-60°C pre-cooling equipment. An internal heater exchanger and a condenser were set in low-temperature cycle. Theoretically the two stages can work stably at setting temperature and the low-temperature cycle can operate independently with aided starting of the high-temperature cycle. The experimental results indicate that the test bed can provide cooling capacity steadily at -46°C and -100°C respectively and the low-temperature cycle cannot operate alone for compressor overload protection. Based on the analysis, the possible reasons and detailed suggestions were put forward.

Thermodynamic Performance Analysis of Ammonia-Water Rankine Cycles Using Heat Sources of High and Low Temperatures

2012 ◽  
Vol 249-250 ◽  
pp. 278-283
Author(s):  
Kyoung Hoon Kim ◽  
Hyung Jong Ko ◽  
Se Woong Kim
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Thermal Efficiency ◽  
Low Temperatures ◽  
Ammonia Concentration ◽  
Working Fluid ◽  
Heat Sources ◽  
Ammonia Water ◽  
High And Low Temperatures ◽  
System Variables

In this study, thermodynamic performances of ammonia-water Rankine (AWR) cycle and regenerative Rankine (AWRR) cycle are comparatively investigated. Special attention is focused on the effects of ammonia concentration and turbine inlet pressure on the performance of system using heat sources of high temperature of 300 oC and low temperature of 150 oC. The behavior of important system variables including mass flow ratio of working fluid, net work production, and thermal efficiency are closely examined. Results show that performance characteristics for heat sources of high and low temperatures are quite different each other. For the high-temperature source, the thermal efficiency has a minimum in AWR system while it has a maximum in AWRR with respect to ammonia concentration in the range of 65% to 75%. For low-temperature source, however, the thermal efficiency decreases with ammonia concentration in the range of ammonia concentration higher than 95% for both AWR system and AWRR system and the effect of regenerator is negligible.

Experimental Investigation of Ejector Refrigeration System With Double Condensers

2018 ◽  
Author(s):  
H. H. Sait ◽  
B. A. Habibullah ◽  
N. Turkman ◽  
H. B. Ma
Keyword(s):  
Experimental Investigation ◽  
High Temperature ◽  
Low Temperature ◽  
Air Conditioning ◽  
Experimental System ◽  
Back Pressure ◽  
Coefficient Of Performance ◽  
Refrigeration System ◽  
Energy Applications ◽  
Waste Energy

This paper presents the results of an experimental investigation of a steam jet refrigerator suitable for renewable or low-medium grade waste energy applications. An experimental system of an ejector refrigeration system was constructed and fabricated. Different parameters of the ejector refrigeration system were investigated, such as the high-temperature evaporator (HTE) temperature, low temperature evaporator (LTE) temperature, and back pressure. The coefficient of performance (COP) of the ejector refrigeration system was determined. In addition, the effects of the operating temperatures on the COP and critical back pressure were investigated. The results are expected to motivate the use of ejector refrigeration systems for air-conditioning.

Cycling ambient temperature effect on boar semen

1984 ◽  
Vol 38 (1) ◽  
pp. 129-132 ◽  
Author(s):  
H. Heitman ◽  
J. R. Cockrell ◽  
S. R. Morrison
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Ambient Temperature ◽  
Temperature Stress ◽  
Semen Quality ◽  
High Temperature Stress ◽  
Low Temperature Stress ◽  
Temperature Cycle ◽  
Control Group ◽  
Medium Temperature

ABSTRACTTwenty-four 1-year-old boars of proven fertility were assigned randomly to one of two temperature-controlled trailers. A control group in each trial was held at 17 ± 0·5°C while the other group was exposed to a diurnal ambient temperature cycle. Cycles followed a sine-wave pattern with minimum and maximum temperatures occurring at 04.00 and 16.00 h respectively. Cycling temperature ranges were 17 to 33 ± 0·5°C (low-temperature stress), 19·5 to 35·5 ± 0·5°C (medium-temperature stress), and 22 to 38 ± 0·5°C (high-temperature stress). Semen samples were collected every 3 or 4 days over an experimental period of 42 days.Low-temperature stress and medium-temperature stress boars were not affected significantly in the five parameters of semen quality observed. The difference between controls and high-temperature stress boars was highly significant for motility, abnormal spermatozoa, gel-free volume, and total spermatozoa per ejaculate. Concentration of spermatozoa was not affected by treatment. Significant time effects were observed for motility, abnormal spermatozoa and total spermotozoa per ejaculate. Significant differences began to appear after 2 or 3 weeks and changes still appeared to be occurring at 6 weeks.

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