The Experts below are selected from a list of 14382 Experts worldwide ranked by ideXlab platform
Maoqiong Gong - One of the best experts on this subject based on the ideXlab platform.
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experimental research on a 4 k hybrid refrigerator combining gm gas Refrigeration Effect with magnetic Refrigeration Effect
Cryogenics, 2019Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Xinqi Zheng, Maoqiong GongAbstract:Abstract A hybrid cryogenic refrigerator that combines the magnetic Refrigeration Effect with the GM Refrigeration Effect has been experimentally studied. ErNi and TmCuAl, which have large magnetocaloric Effects, are used to fill the second (low-temperature) stage regenerator of a GM refrigerator and put in a magnetic field varying from 0 to 1.1 T. A phase angle α is defined as the phase between the varying magnetic field and displacer movement and can be tuned in order to find the best timing between the magnetic Refrigeration and the GM Refrigeration cycle. Efforts have also been made to suppress eddy current losses induced due to the varying magnetic field through the cold head. A phase angle of 60° was found to generate best cooling performance through experiments. A minimal no-load temperature of 3.5 K was obtained at 0.5 Hz while the GM Refrigeration alone can only generate a no-load temperature of 4.2 K.
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improvements of a room temperature magnetic refrigerator combined with stirling cycle Refrigeration Effect
International Journal of Refrigeration-revue Internationale Du Froid, 2016Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Chengchun Tang, J C Jia, Maoqiong GongAbstract:Abstract A high pressure hybrid refrigerator that combines the active magnetic Refrigeration Effect with the Stirling cycle Refrigeration Effect at room temperature is studied here. In the apparatus, a helium-gas-filled alfa-type Stirling refrigerator uses Gd sheets as the regenerator and the regenerator is put in a magnetic field varying from 0 to 1.4 T, which is provided by a Halbach-type rotary permanent magnet assembly. With an operating pressure of 5.5 MPa and a frequency of 2.5 Hz, a no-load temperature of 273.8 K was reached in 9 minutes, which is lower than that of 277.6 K for pure Stirling cycle. For the hybrid operation, cooling powers of 40.3 W and 56.4 W were achieved over temperature spans of 15 K and 12 K, respectively. For the latter case, the cooling power improves by 28.5% if compared with that exploiting only the Stirling cycle Refrigeration Effect.
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design and performance of a room temperature hybrid magnetic refrigerator combined with stirling gas Refrigeration Effect
International Journal of Refrigeration-revue Internationale Du Froid, 2013Co-Authors: Maoqiong Gong, Wei Dai, Hui Zhang, Jun ShenAbstract:Abstract The experimental prototype described in this work is a hybrid refrigerator that combines the active magnetic Refrigeration Effect with the Stirling gas regenerative Refrigeration Effect. In this prototype, gadolinium sheets are packed in the regenerator matrix for both Stirling and active magnetic regenerative Refrigeration. Experimental tests were carried out to measure the cooling performance of this hybrid prototype. The influence of the phase angle on the cooling performance was investigated, and a reasonable phase angle of 90° was determined to obtain optimal cooling performance. By combining the two Refrigeration Effects, a minimum cooling temperature without heat load of 3.5 °C was reached, which is lower than that of 6.5 °C for the pure Stirling Refrigeration Effect without the magnetic cooling Effect. The results of this study show that the cooling performance is improved by 24% for the hybrid Effects compared with that exploiting only the Stirling gas Refrigeration Effect.
Jun Shen - One of the best experts on this subject based on the ideXlab platform.
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experimental research on a 4 k hybrid refrigerator combining gm gas Refrigeration Effect with magnetic Refrigeration Effect
Cryogenics, 2019Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Xinqi Zheng, Maoqiong GongAbstract:Abstract A hybrid cryogenic refrigerator that combines the magnetic Refrigeration Effect with the GM Refrigeration Effect has been experimentally studied. ErNi and TmCuAl, which have large magnetocaloric Effects, are used to fill the second (low-temperature) stage regenerator of a GM refrigerator and put in a magnetic field varying from 0 to 1.1 T. A phase angle α is defined as the phase between the varying magnetic field and displacer movement and can be tuned in order to find the best timing between the magnetic Refrigeration and the GM Refrigeration cycle. Efforts have also been made to suppress eddy current losses induced due to the varying magnetic field through the cold head. A phase angle of 60° was found to generate best cooling performance through experiments. A minimal no-load temperature of 3.5 K was obtained at 0.5 Hz while the GM Refrigeration alone can only generate a no-load temperature of 4.2 K.
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improvements of a room temperature magnetic refrigerator combined with stirling cycle Refrigeration Effect
International Journal of Refrigeration-revue Internationale Du Froid, 2016Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Chengchun Tang, J C Jia, Maoqiong GongAbstract:Abstract A high pressure hybrid refrigerator that combines the active magnetic Refrigeration Effect with the Stirling cycle Refrigeration Effect at room temperature is studied here. In the apparatus, a helium-gas-filled alfa-type Stirling refrigerator uses Gd sheets as the regenerator and the regenerator is put in a magnetic field varying from 0 to 1.4 T, which is provided by a Halbach-type rotary permanent magnet assembly. With an operating pressure of 5.5 MPa and a frequency of 2.5 Hz, a no-load temperature of 273.8 K was reached in 9 minutes, which is lower than that of 277.6 K for pure Stirling cycle. For the hybrid operation, cooling powers of 40.3 W and 56.4 W were achieved over temperature spans of 15 K and 12 K, respectively. For the latter case, the cooling power improves by 28.5% if compared with that exploiting only the Stirling cycle Refrigeration Effect.
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design and performance of a room temperature hybrid magnetic refrigerator combined with stirling gas Refrigeration Effect
International Journal of Refrigeration-revue Internationale Du Froid, 2013Co-Authors: Maoqiong Gong, Wei Dai, Hui Zhang, Jun ShenAbstract:Abstract The experimental prototype described in this work is a hybrid refrigerator that combines the active magnetic Refrigeration Effect with the Stirling gas regenerative Refrigeration Effect. In this prototype, gadolinium sheets are packed in the regenerator matrix for both Stirling and active magnetic regenerative Refrigeration. Experimental tests were carried out to measure the cooling performance of this hybrid prototype. The influence of the phase angle on the cooling performance was investigated, and a reasonable phase angle of 90° was determined to obtain optimal cooling performance. By combining the two Refrigeration Effects, a minimum cooling temperature without heat load of 3.5 °C was reached, which is lower than that of 6.5 °C for the pure Stirling Refrigeration Effect without the magnetic cooling Effect. The results of this study show that the cooling performance is improved by 24% for the hybrid Effects compared with that exploiting only the Stirling gas Refrigeration Effect.
Xinqiang Gao - One of the best experts on this subject based on the ideXlab platform.
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experimental research on a 4 k hybrid refrigerator combining gm gas Refrigeration Effect with magnetic Refrigeration Effect
Cryogenics, 2019Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Xinqi Zheng, Maoqiong GongAbstract:Abstract A hybrid cryogenic refrigerator that combines the magnetic Refrigeration Effect with the GM Refrigeration Effect has been experimentally studied. ErNi and TmCuAl, which have large magnetocaloric Effects, are used to fill the second (low-temperature) stage regenerator of a GM refrigerator and put in a magnetic field varying from 0 to 1.1 T. A phase angle α is defined as the phase between the varying magnetic field and displacer movement and can be tuned in order to find the best timing between the magnetic Refrigeration and the GM Refrigeration cycle. Efforts have also been made to suppress eddy current losses induced due to the varying magnetic field through the cold head. A phase angle of 60° was found to generate best cooling performance through experiments. A minimal no-load temperature of 3.5 K was obtained at 0.5 Hz while the GM Refrigeration alone can only generate a no-load temperature of 4.2 K.
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improvements of a room temperature magnetic refrigerator combined with stirling cycle Refrigeration Effect
International Journal of Refrigeration-revue Internationale Du Froid, 2016Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Chengchun Tang, J C Jia, Maoqiong GongAbstract:Abstract A high pressure hybrid refrigerator that combines the active magnetic Refrigeration Effect with the Stirling cycle Refrigeration Effect at room temperature is studied here. In the apparatus, a helium-gas-filled alfa-type Stirling refrigerator uses Gd sheets as the regenerator and the regenerator is put in a magnetic field varying from 0 to 1.4 T, which is provided by a Halbach-type rotary permanent magnet assembly. With an operating pressure of 5.5 MPa and a frequency of 2.5 Hz, a no-load temperature of 273.8 K was reached in 9 minutes, which is lower than that of 277.6 K for pure Stirling cycle. For the hybrid operation, cooling powers of 40.3 W and 56.4 W were achieved over temperature spans of 15 K and 12 K, respectively. For the latter case, the cooling power improves by 28.5% if compared with that exploiting only the Stirling cycle Refrigeration Effect.
Wei Dai - One of the best experts on this subject based on the ideXlab platform.
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experimental research on a 4 k hybrid refrigerator combining gm gas Refrigeration Effect with magnetic Refrigeration Effect
Cryogenics, 2019Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Xinqi Zheng, Maoqiong GongAbstract:Abstract A hybrid cryogenic refrigerator that combines the magnetic Refrigeration Effect with the GM Refrigeration Effect has been experimentally studied. ErNi and TmCuAl, which have large magnetocaloric Effects, are used to fill the second (low-temperature) stage regenerator of a GM refrigerator and put in a magnetic field varying from 0 to 1.1 T. A phase angle α is defined as the phase between the varying magnetic field and displacer movement and can be tuned in order to find the best timing between the magnetic Refrigeration and the GM Refrigeration cycle. Efforts have also been made to suppress eddy current losses induced due to the varying magnetic field through the cold head. A phase angle of 60° was found to generate best cooling performance through experiments. A minimal no-load temperature of 3.5 K was obtained at 0.5 Hz while the GM Refrigeration alone can only generate a no-load temperature of 4.2 K.
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improvements of a room temperature magnetic refrigerator combined with stirling cycle Refrigeration Effect
International Journal of Refrigeration-revue Internationale Du Froid, 2016Co-Authors: Jun Shen, Xinqiang Gao, Wei Dai, Chengchun Tang, J C Jia, Maoqiong GongAbstract:Abstract A high pressure hybrid refrigerator that combines the active magnetic Refrigeration Effect with the Stirling cycle Refrigeration Effect at room temperature is studied here. In the apparatus, a helium-gas-filled alfa-type Stirling refrigerator uses Gd sheets as the regenerator and the regenerator is put in a magnetic field varying from 0 to 1.4 T, which is provided by a Halbach-type rotary permanent magnet assembly. With an operating pressure of 5.5 MPa and a frequency of 2.5 Hz, a no-load temperature of 273.8 K was reached in 9 minutes, which is lower than that of 277.6 K for pure Stirling cycle. For the hybrid operation, cooling powers of 40.3 W and 56.4 W were achieved over temperature spans of 15 K and 12 K, respectively. For the latter case, the cooling power improves by 28.5% if compared with that exploiting only the Stirling cycle Refrigeration Effect.
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design and performance of a room temperature hybrid magnetic refrigerator combined with stirling gas Refrigeration Effect
International Journal of Refrigeration-revue Internationale Du Froid, 2013Co-Authors: Maoqiong Gong, Wei Dai, Hui Zhang, Jun ShenAbstract:Abstract The experimental prototype described in this work is a hybrid refrigerator that combines the active magnetic Refrigeration Effect with the Stirling gas regenerative Refrigeration Effect. In this prototype, gadolinium sheets are packed in the regenerator matrix for both Stirling and active magnetic regenerative Refrigeration. Experimental tests were carried out to measure the cooling performance of this hybrid prototype. The influence of the phase angle on the cooling performance was investigated, and a reasonable phase angle of 90° was determined to obtain optimal cooling performance. By combining the two Refrigeration Effects, a minimum cooling temperature without heat load of 3.5 °C was reached, which is lower than that of 6.5 °C for the pure Stirling Refrigeration Effect without the magnetic cooling Effect. The results of this study show that the cooling performance is improved by 24% for the hybrid Effects compared with that exploiting only the Stirling gas Refrigeration Effect.
Steven M. Sait - One of the best experts on this subject based on the ideXlab platform.
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A review on boilers energy use, energy savings, and emissions reductions
Renewable and Sustainable Energy Reviews, 2017Co-Authors: M. C. Barma, B. A. Akash, S. M. A. Rahman, Amine Allouhi, Rahman Saidur, Steven M. SaitAbstract:Boiler is a widely used steam generating system in industries and power plants. A significant portion of the world energy consumption is being used in boilers. A small improvement on the boiler efficiency will help to save a large amount of fossil fuels and to reduce CO2emission. This study describes the amount of energy used in boilers, ways employed to evaluate their energy efficiency, losses occurred and their causes, ways of waste heat recovery and minimizing heat loss using technologies, role of maintenance activities, and technical education to make people aware of the energy usage. Latest published literature on the above mentioned topics which includes PhD and MSc theses, journal articles, conference proceedings, reports and web materials have been reviewed and reported. It is found that a substantial amount of energy is wasted through high temperature flue gas or exhaust of the boiler. Also, some other unavoidable losses occurr due to various reasons. However, waste heat could be recovered using different technologies as a useful form of energy such as electricity, heat, Refrigeration Effect, etc. The efficiency of the boiler can be improved by doing scheduled maintenance work, which helps to run a boiler at its highest efficiency. In order to create awareness about energy use, education programs and seminars need to be arranged on regular basis for the staff involved. This will help them to understand the importance of the energy as being used in the boiler system as well as the impact of their actions during the operation of the boiler.