The corrosion inhibition performance of co-immobilized lysozyme and lipase was investigated in a recirculating cooling water system. Four methods were carried out in co-immobilization, and the operating parameters wer...The corrosion inhibition performance of co-immobilized lysozyme and lipase was investigated in a recirculating cooling water system. Four methods were carried out in co-immobilization, and the operating parameters were optimized by using the respond surface methodology(RSM). The corrosion inhibition performance of co-immobilized lipase and lysozyme was evaluated by weight loss measurements and electrochemical measurements. The results revealed that the optimal co-immobilization method should be the sequential immobilization of lysozyme and then lipase. The inhibition efficiency was 86.10% under the optimal co-immobilized conditions. Electrochemical data showed that co-immobilized lysozyme and lipase was a mixed-type inhibitor and the corrosion inhibition efficiency was 81%.展开更多
Recent research on deterministic methods for circulating cooling water systems optimization has been well developed. However, the actual operating conditions of the system are mostly variable, so the system obtained u...Recent research on deterministic methods for circulating cooling water systems optimization has been well developed. However, the actual operating conditions of the system are mostly variable, so the system obtained under deterministic conditions may not be stable and economical. This paper studies the optimization of circulating cooling water systems under uncertain circumstance. To improve the reliability of the system and reduce the water and energy consumption, the influence of different uncertain parameters is taken into consideration. The chance constrained programming method is used to build a model under uncertain conditions, where the confidence level indicates the degree of constraint violation. Probability distribution functions are used to describe the form of uncertain parameters. The objective is to minimize the total cost and obtain the optimal cooling network configuration simultaneously.An algorithm based on Monte Carlo method is proposed, and GAMS software is used to solve the mixed integer nonlinear programming model. A case is optimized to verify the validity of the model. Compared with the deterministic optimization method, the results show that when considering the different types of uncertain parameters, a system with better economy and reliability can be obtained(total cost can be reduced at least 2%).展开更多
MIC is one of the main problems of circulating cooling water system. The direct economic loss by MIC is about 300 to 500 billion dollars. It is good to understand MIC in order to control MIC. Source and species of mic...MIC is one of the main problems of circulating cooling water system. The direct economic loss by MIC is about 300 to 500 billion dollars. It is good to understand MIC in order to control MIC. Source and species of microorganisms was introduced firstly. There are three kinds of microorganisms in the system, including bacteria, fungi and algae. Species of these microorganisms are shown in the paper. Then, mechanisms of MIC are analysed. Although there is no universal mechanism of MIC, MIC is still mainly an electrochemical corrosion in nature. Meanwhile, the mechanisms on SRB and iron bacteria are introduced in details. At last, several methods of microorganisms control are put forward in the paper.展开更多
In order to solve the problems including pipe corrosion, scaling and microbial growth, which severely threat safe op-eration of circulating cooling water system, this paper proposes ion exchange softening and alkaliza...In order to solve the problems including pipe corrosion, scaling and microbial growth, which severely threat safe op-eration of circulating cooling water system, this paper proposes ion exchange softening and alkalization process to solve these problems and carries out a series of studies to study the feasibility of ion exchange softening and alkaliza-tion process in the simulation process of circulating cooling water system. The studies include product water quality of ion exchange softening and alkalization process, effect on the performance of carbon steel and brass, and the inhibition that suppresses microbial growth. The results indicate that ion exchange softening and alkalization process is feasible to prevent the circulating cooling water system from scaling, pipe corrosion, and microbial growth without any other chemicals. Thus circulating cooling water system can achieve zerodischarge of wastewater.展开更多
Mesoporous SiO_2 microspheres were synthesized using the sol-gel method and were characterized by TEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore diameter...Mesoporous SiO_2 microspheres were synthesized using the sol-gel method and were characterized by TEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore diameter is 2.55 nm, while the specific surface area is 1 088.9 m2/g. Mesoporous SiO_2 microspheres adsorb glutaraldehyde and immobilize laccase by means of the aldehyde group in glutaral which can react with the amidogen of laccase. The immobilization conditions were optimized at a glutaraldehyde concentration of 0.75%, a crosslinking time of 8 h, a laccase concentration of 0.04 L/L and an immobilization time of 10 h. When diesel leakage concentration was 80 mg/L, the highest corrosion inhibition efficiency of immobilized laccase reached 49.23%, which was slightly lower than the corrosion inhibition efficiency of free laccase(59%). The diesel degradation ratio could reach up to 45%. It has been proved that the immobilized laccase could degrade diesel to inhibit corrosion.展开更多
In a district heating and cooling system, i.e. Beijing combined heating cooling and power (CHCP) system studied here, the high temperature water generated by two cogeneration plants circulates through a network betwee...In a district heating and cooling system, i.e. Beijing combined heating cooling and power (CHCP) system studied here, the high temperature water generated by two cogeneration plants circulates through a network between the plants and heat substations. At heat substations, the supply water of high temperature from the network drives absorption chillers for air-conditioning in summer and meets space heating demands in winter or domestic hot water demands by heat exchangers in the whole year. The parameters, i.e. supply/return water temperatures in the network, have a great impact on primary energy consumption (PEC) of the absorption chillers, circulation pumps and domestic hot water (DHW), which is studied in this paper.展开更多
基金financially supported by the National Natural Science Foundation of China (project 21077133)the Natural Foundation of Shandong Province and the Top Talent Project of China University of Petroleum (16RC17040003)
文摘The corrosion inhibition performance of co-immobilized lysozyme and lipase was investigated in a recirculating cooling water system. Four methods were carried out in co-immobilization, and the operating parameters were optimized by using the respond surface methodology(RSM). The corrosion inhibition performance of co-immobilized lipase and lysozyme was evaluated by weight loss measurements and electrochemical measurements. The results revealed that the optimal co-immobilization method should be the sequential immobilization of lysozyme and then lipase. The inhibition efficiency was 86.10% under the optimal co-immobilized conditions. Electrochemical data showed that co-immobilized lysozyme and lipase was a mixed-type inhibitor and the corrosion inhibition efficiency was 81%.
基金Financial support from the National Natural Science Foundation of China (22022816, 22078358)。
文摘Recent research on deterministic methods for circulating cooling water systems optimization has been well developed. However, the actual operating conditions of the system are mostly variable, so the system obtained under deterministic conditions may not be stable and economical. This paper studies the optimization of circulating cooling water systems under uncertain circumstance. To improve the reliability of the system and reduce the water and energy consumption, the influence of different uncertain parameters is taken into consideration. The chance constrained programming method is used to build a model under uncertain conditions, where the confidence level indicates the degree of constraint violation. Probability distribution functions are used to describe the form of uncertain parameters. The objective is to minimize the total cost and obtain the optimal cooling network configuration simultaneously.An algorithm based on Monte Carlo method is proposed, and GAMS software is used to solve the mixed integer nonlinear programming model. A case is optimized to verify the validity of the model. Compared with the deterministic optimization method, the results show that when considering the different types of uncertain parameters, a system with better economy and reliability can be obtained(total cost can be reduced at least 2%).
文摘MIC is one of the main problems of circulating cooling water system. The direct economic loss by MIC is about 300 to 500 billion dollars. It is good to understand MIC in order to control MIC. Source and species of microorganisms was introduced firstly. There are three kinds of microorganisms in the system, including bacteria, fungi and algae. Species of these microorganisms are shown in the paper. Then, mechanisms of MIC are analysed. Although there is no universal mechanism of MIC, MIC is still mainly an electrochemical corrosion in nature. Meanwhile, the mechanisms on SRB and iron bacteria are introduced in details. At last, several methods of microorganisms control are put forward in the paper.
文摘In order to solve the problems including pipe corrosion, scaling and microbial growth, which severely threat safe op-eration of circulating cooling water system, this paper proposes ion exchange softening and alkalization process to solve these problems and carries out a series of studies to study the feasibility of ion exchange softening and alkaliza-tion process in the simulation process of circulating cooling water system. The studies include product water quality of ion exchange softening and alkalization process, effect on the performance of carbon steel and brass, and the inhibition that suppresses microbial growth. The results indicate that ion exchange softening and alkalization process is feasible to prevent the circulating cooling water system from scaling, pipe corrosion, and microbial growth without any other chemicals. Thus circulating cooling water system can achieve zerodischarge of wastewater.
基金supported by the Foundation for Top Talents Program of China University of Petroleum
文摘Mesoporous SiO_2 microspheres were synthesized using the sol-gel method and were characterized by TEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore diameter is 2.55 nm, while the specific surface area is 1 088.9 m2/g. Mesoporous SiO_2 microspheres adsorb glutaraldehyde and immobilize laccase by means of the aldehyde group in glutaral which can react with the amidogen of laccase. The immobilization conditions were optimized at a glutaraldehyde concentration of 0.75%, a crosslinking time of 8 h, a laccase concentration of 0.04 L/L and an immobilization time of 10 h. When diesel leakage concentration was 80 mg/L, the highest corrosion inhibition efficiency of immobilized laccase reached 49.23%, which was slightly lower than the corrosion inhibition efficiency of free laccase(59%). The diesel degradation ratio could reach up to 45%. It has been proved that the immobilized laccase could degrade diesel to inhibit corrosion.
文摘In a district heating and cooling system, i.e. Beijing combined heating cooling and power (CHCP) system studied here, the high temperature water generated by two cogeneration plants circulates through a network between the plants and heat substations. At heat substations, the supply water of high temperature from the network drives absorption chillers for air-conditioning in summer and meets space heating demands in winter or domestic hot water demands by heat exchangers in the whole year. The parameters, i.e. supply/return water temperatures in the network, have a great impact on primary energy consumption (PEC) of the absorption chillers, circulation pumps and domestic hot water (DHW), which is studied in this paper.
