Process heating constitutes a significant share of final energy consumption in the industrial sector around the world.In this paper,a high-temperature heat pump(HTHP)using flash tank vapor injection technology(FTVI)is...Process heating constitutes a significant share of final energy consumption in the industrial sector around the world.In this paper,a high-temperature heat pump(HTHP)using flash tank vapor injection technology(FTVI)is proposed to develop low-temperature geothermal source for industrial process heating with temperature above 100°C.With heat sink output temperatures between 120°C and 150°C,the thermo-economic performance of the FTVI HTHP system using R1234ze(Z)as refrigerant is analyzed and also compared to the single-stage vapor compression(SSVC)system by employing the developed mathematical model.The coefficient of performance(COP),exergy efficiency(ηexe),net present value(NPV)and payback period(PBP)are used as performance indicators.The results show that under the typical working conditions,the COP andηexe of FTVI HTHP system are 3.00 and 59.66%,respectively,and the corresponding NPV and PBP reach 8.13×106 CNY and 4.13 years,respectively.Under the high-temperature heating conditions,the thermo-economic performance of the FTVI HTHP system is significantly better than that of the SSVC system,and the larger the temperature lift,the greater the thermo-economic advantage of the FTVI HTHP system.Additionally,the FTVI HTHP system is more capable than the SSVC system in absorbing the financial risks associated with changes of electricity price and natural gas price.展开更多
BACKGROUND Esophageal-gastro varices bleeding(EGVB)is the most widely known cause of mortality in individuals with cirrhosis,with an occurrence rate of 5%to 15%.Among them,gastric varices bleeding(GVB)is less frequent...BACKGROUND Esophageal-gastro varices bleeding(EGVB)is the most widely known cause of mortality in individuals with cirrhosis,with an occurrence rate of 5%to 15%.Among them,gastric varices bleeding(GVB)is less frequent than esophageal varices bleeding(EVB),but the former is a more critical illness and has a higher mortality rate.At present,endoscopic variceal histoacryl injection therapy(EVHT)is safe and effective,and it has been recommended by relevant guidelines as the primary method for the treatment of GVB.However,gastric varices after endoscopic treatment still have a high rate of early rebleeding,which is mainly related to complications of its treatment,such as bleeding from drained ulcers,rebleeding of varices etc.Therefore,preventing early postoperative rebleeding is very important to improve the quality of patient survival and outcomes.AIM To assess the efficacy of aluminium phosphate gel(APG)combined with proton pump inhibitor(PPI)in preventing early rebleeding after EVHT in individuals with GVB.METHODS Medical history of 196 individuals with GVB was obtained who were diagnosed using endoscopy and treated with EVHT in Shenzhen People's Hospital from January 2016 to December 2021.Based on the selection criteria,101 patients were sorted into the PPI alone treatment group,and 95 patients were sorted into the PPI combined with the APG treatment group.The incidences of early rebleeding and corresponding complications within 6 wk after treatment were compared between both groups.Statistical methods were performed by two-sample t-test,Wilcoxon rank sum test andχ2 test.RESULTS No major variations were noted between the individuals of the two groups in terms of age,gender,Model for End-Stage Liver Disease score,coagulation function,serum albumin,hemoglobin,type of gastric varices,the dose of tissue glue injection and EV that needed to be treated simultaneously.The early rebleeding rate in PPI+APG group was 3.16%(3/95),which was much lower than that in the PPI group(12.87%,13/101)(P=0.013).Causes of early rebleeding:the incidence of gastric ulcer bleeding in the PPI+APG group was 2.11%(2/95),which was reduced in comparison to that in the PPI group(11.88%,12/101)(P=0.008);the incidence of venous bleeding in PPI+APG group and PPI group was 1.05%(1/95)and 0.99%(1/101),respectively,and there was no significant difference between them(0.999).The early mortality rate was 0 in both groups within 6 wk after the operation,and the low mortality rate was related to the timely hospitalization and active treatment of all patients with rebleeding.The overall incidence of complications in the PPI+APG group was 12.63%(12/95),which was not significantly different from 13.86%(14/101)in the PPI group(P=0.800).of abdominal pain in the PPI+APG group was 3.16%(3/95),which was lower than that in the PPI group(11.88%,12/101)(P=0.022).However,due to aluminum phosphate gel usage,the incidence of constipation in the PPI+APG group was 9.47%(9/95),which was higher than that in the PPI group(1.98%,2/101)(P=0.023),but the health of the patients could be improved by increasing drinking water or oral lactulose.No patients in either group developed spontaneous peritonitis after taking PPI,and none developed hepatic encephalopathy and ectopic embolism within 6 wk of EVHT treatment.CONCLUSION PPI combined with APG can significantly reduce the incidence of early rebleeding and postoperative abdominal pain in cirrhotic patients with GVB after taking EVHT.展开更多
The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variat...The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment, The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.展开更多
The cycle fuel injection quantity is accurately measured for electronic unit pump (EUP) operating at high, middle and low speeds by using displacement method based on EFS instantaneous mono-injector qualifier. On th...The cycle fuel injection quantity is accurately measured for electronic unit pump (EUP) operating at high, middle and low speeds by using displacement method based on EFS instantaneous mono-injector qualifier. On the basis of the experi- mental data about fuel injection quantity and fuel pressure, the variation of inconsistency in fuel injection quantity of EUP and the influence factors in different operating conditions are concluded. The results show that the inconsistency is lowest in maximum torque condition, while on the start and maximum power conditions, it is higher.展开更多
An air source heat pump(ASHP)with refrigerant injection is proposed for the air conditioning system of electric vehicles(EVs),especially for efficient heating in cold winter,when there is no wasted heat of engines.The...An air source heat pump(ASHP)with refrigerant injection is proposed for the air conditioning system of electric vehicles(EVs),especially for efficient heating in cold winter,when there is no wasted heat of engines.The simulation model is built with the framework of two-phase fluid network,where the compressor is separated as two compressors and the economizer is treated as two heat exchangers in the injection path and the main refrigerant path.With the validated simulation model,the heating performance is analyzed,and the results show that the coefficient of performance(COP)of ASHP with refrigerant injection is higher than 1.4 and the discharge temperature is less than 100℃ when the outdoor temperature is-20℃.The above performance ensures that the air conditioning system and EVs can operate normally with high efficiency even in the cold winter,which is much helpful for the practicability of EVs.展开更多
Injection recovery is an important measure for increasing the oil recovery rate of an oil field. One way is that centrifugal pumps or plunger pumps are used in an injection station to responsible for injection over a ...Injection recovery is an important measure for increasing the oil recovery rate of an oil field. One way is that centrifugal pumps or plunger pumps are used in an injection station to responsible for injection over a large area under the same pressure. This method is ineffective for low-permeability layers. For the oilfields in dispersed distribution in the marginal areas of Daqing, the low water-absorbing section needs an injection with a high delivery pressure and a low discharge capacity; another way is to install the submersible electric pump upside down, but because the submersible electric pump and the motor are underground, it is difficult for installation and maintenance. Introduced in this paper is the development and application of a surface high-pressure injection device with a submersible electric pump. Bysuccessful resolving some problems, such as the axial force of the submersible electric pump, sealing, level regulation of the pump, coaxiality and vibration, the device has the good points of running smoothly, moving easily, installation and maintains quickly and long period of running. This device can effectively solve the injection of the low water-absorbing section and of oilfields in dispersed locations. The recovery rate of oilfields is also enhanced.展开更多
At present in the process of water injection station operation, starting and stopping the pump caused system pressure fluctuations, and the fluctuations caused many problems about downstream injection wells. In order ...At present in the process of water injection station operation, starting and stopping the pump caused system pressure fluctuations, and the fluctuations caused many problems about downstream injection wells. In order to eliminate the fluctuations and reduce problems, taking start pump, connect pump test under pressure in the water injection station installed the rotor frequency control system Changqing oil field developed. During the experiment, by progressively increasing the pressure pump to verify start pump with pressure feasibility test, the result shows when the pressure in the 0-25MPa pressure start and connect pump can be realized, and forecast the maximum pressure of the current start of the station with pressure pump. Start pump with pressure achieve the elimination of pressure fluctuations, provide the prerequisites about realizeing stable water injection pressure, and ultimately realize oil field water injection station to be automatic water injection laid a foundation.展开更多
基金supported by the Carbon Peak and Carbon Neutralization Science and Technology Innovation Special Fund of Jiangsu Province,China(No.BE2022859)Natural Science Foundation of Guangdong Province,China(No.2021A1515011763).
文摘Process heating constitutes a significant share of final energy consumption in the industrial sector around the world.In this paper,a high-temperature heat pump(HTHP)using flash tank vapor injection technology(FTVI)is proposed to develop low-temperature geothermal source for industrial process heating with temperature above 100°C.With heat sink output temperatures between 120°C and 150°C,the thermo-economic performance of the FTVI HTHP system using R1234ze(Z)as refrigerant is analyzed and also compared to the single-stage vapor compression(SSVC)system by employing the developed mathematical model.The coefficient of performance(COP),exergy efficiency(ηexe),net present value(NPV)and payback period(PBP)are used as performance indicators.The results show that under the typical working conditions,the COP andηexe of FTVI HTHP system are 3.00 and 59.66%,respectively,and the corresponding NPV and PBP reach 8.13×106 CNY and 4.13 years,respectively.Under the high-temperature heating conditions,the thermo-economic performance of the FTVI HTHP system is significantly better than that of the SSVC system,and the larger the temperature lift,the greater the thermo-economic advantage of the FTVI HTHP system.Additionally,the FTVI HTHP system is more capable than the SSVC system in absorbing the financial risks associated with changes of electricity price and natural gas price.
基金Supported by Clinical Research and Cultivation Project of Shenzhen People's Hospital,No.SYLCYJ202116.
文摘BACKGROUND Esophageal-gastro varices bleeding(EGVB)is the most widely known cause of mortality in individuals with cirrhosis,with an occurrence rate of 5%to 15%.Among them,gastric varices bleeding(GVB)is less frequent than esophageal varices bleeding(EVB),but the former is a more critical illness and has a higher mortality rate.At present,endoscopic variceal histoacryl injection therapy(EVHT)is safe and effective,and it has been recommended by relevant guidelines as the primary method for the treatment of GVB.However,gastric varices after endoscopic treatment still have a high rate of early rebleeding,which is mainly related to complications of its treatment,such as bleeding from drained ulcers,rebleeding of varices etc.Therefore,preventing early postoperative rebleeding is very important to improve the quality of patient survival and outcomes.AIM To assess the efficacy of aluminium phosphate gel(APG)combined with proton pump inhibitor(PPI)in preventing early rebleeding after EVHT in individuals with GVB.METHODS Medical history of 196 individuals with GVB was obtained who were diagnosed using endoscopy and treated with EVHT in Shenzhen People's Hospital from January 2016 to December 2021.Based on the selection criteria,101 patients were sorted into the PPI alone treatment group,and 95 patients were sorted into the PPI combined with the APG treatment group.The incidences of early rebleeding and corresponding complications within 6 wk after treatment were compared between both groups.Statistical methods were performed by two-sample t-test,Wilcoxon rank sum test andχ2 test.RESULTS No major variations were noted between the individuals of the two groups in terms of age,gender,Model for End-Stage Liver Disease score,coagulation function,serum albumin,hemoglobin,type of gastric varices,the dose of tissue glue injection and EV that needed to be treated simultaneously.The early rebleeding rate in PPI+APG group was 3.16%(3/95),which was much lower than that in the PPI group(12.87%,13/101)(P=0.013).Causes of early rebleeding:the incidence of gastric ulcer bleeding in the PPI+APG group was 2.11%(2/95),which was reduced in comparison to that in the PPI group(11.88%,12/101)(P=0.008);the incidence of venous bleeding in PPI+APG group and PPI group was 1.05%(1/95)and 0.99%(1/101),respectively,and there was no significant difference between them(0.999).The early mortality rate was 0 in both groups within 6 wk after the operation,and the low mortality rate was related to the timely hospitalization and active treatment of all patients with rebleeding.The overall incidence of complications in the PPI+APG group was 12.63%(12/95),which was not significantly different from 13.86%(14/101)in the PPI group(P=0.800).of abdominal pain in the PPI+APG group was 3.16%(3/95),which was lower than that in the PPI group(11.88%,12/101)(P=0.022).However,due to aluminum phosphate gel usage,the incidence of constipation in the PPI+APG group was 9.47%(9/95),which was higher than that in the PPI group(1.98%,2/101)(P=0.023),but the health of the patients could be improved by increasing drinking water or oral lactulose.No patients in either group developed spontaneous peritonitis after taking PPI,and none developed hepatic encephalopathy and ectopic embolism within 6 wk of EVHT treatment.CONCLUSION PPI combined with APG can significantly reduce the incidence of early rebleeding and postoperative abdominal pain in cirrhotic patients with GVB after taking EVHT.
基金This project is supported by National Natural Science Foundation of China (No.50275102)Opening Foundation of State Key Lab of Fluid Power Transmission and Control of Zhejiang University, China (No.GZKF2002004).
文摘The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment, The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.
文摘The cycle fuel injection quantity is accurately measured for electronic unit pump (EUP) operating at high, middle and low speeds by using displacement method based on EFS instantaneous mono-injector qualifier. On the basis of the experi- mental data about fuel injection quantity and fuel pressure, the variation of inconsistency in fuel injection quantity of EUP and the influence factors in different operating conditions are concluded. The results show that the inconsistency is lowest in maximum torque condition, while on the start and maximum power conditions, it is higher.
基金supported by the National Key Research and Development Program of China(No.2016YFB0601602)National Natural Science Foundation of China(No.51676199)
文摘An air source heat pump(ASHP)with refrigerant injection is proposed for the air conditioning system of electric vehicles(EVs),especially for efficient heating in cold winter,when there is no wasted heat of engines.The simulation model is built with the framework of two-phase fluid network,where the compressor is separated as two compressors and the economizer is treated as two heat exchangers in the injection path and the main refrigerant path.With the validated simulation model,the heating performance is analyzed,and the results show that the coefficient of performance(COP)of ASHP with refrigerant injection is higher than 1.4 and the discharge temperature is less than 100℃ when the outdoor temperature is-20℃.The above performance ensures that the air conditioning system and EVs can operate normally with high efficiency even in the cold winter,which is much helpful for the practicability of EVs.
文摘Injection recovery is an important measure for increasing the oil recovery rate of an oil field. One way is that centrifugal pumps or plunger pumps are used in an injection station to responsible for injection over a large area under the same pressure. This method is ineffective for low-permeability layers. For the oilfields in dispersed distribution in the marginal areas of Daqing, the low water-absorbing section needs an injection with a high delivery pressure and a low discharge capacity; another way is to install the submersible electric pump upside down, but because the submersible electric pump and the motor are underground, it is difficult for installation and maintenance. Introduced in this paper is the development and application of a surface high-pressure injection device with a submersible electric pump. Bysuccessful resolving some problems, such as the axial force of the submersible electric pump, sealing, level regulation of the pump, coaxiality and vibration, the device has the good points of running smoothly, moving easily, installation and maintains quickly and long period of running. This device can effectively solve the injection of the low water-absorbing section and of oilfields in dispersed locations. The recovery rate of oilfields is also enhanced.
文摘At present in the process of water injection station operation, starting and stopping the pump caused system pressure fluctuations, and the fluctuations caused many problems about downstream injection wells. In order to eliminate the fluctuations and reduce problems, taking start pump, connect pump test under pressure in the water injection station installed the rotor frequency control system Changqing oil field developed. During the experiment, by progressively increasing the pressure pump to verify start pump with pressure feasibility test, the result shows when the pressure in the 0-25MPa pressure start and connect pump can be realized, and forecast the maximum pressure of the current start of the station with pressure pump. Start pump with pressure achieve the elimination of pressure fluctuations, provide the prerequisites about realizeing stable water injection pressure, and ultimately realize oil field water injection station to be automatic water injection laid a foundation.