39results about How to "Meet operating conditions" patented technology

The invention discloses a comprehensive extraction method of ferro-silico-aluminum in gangue, comprising the following steps of: using gangue as a raw material, crushing, grinding, activating, carrying out acid leaching, filtering, neutralizing free acid in the acid leaching filtered solution by the use of active slag, filtering to obtain a neutralized acid leaching solution, adding a sodium carbonate solution into the neutralized acid leaching solution, adjusting pH value, separating iron and aluminium to obtain hydrous iron oxide, aluminium hydroxide and a by-product sodium sulphate, adding sodium sulphate and coke into the acid leaching slag which has undergone acid leaching and filtration, carrying out a high-temperature melt reaction to recover silicon so as to prepare soluble glass, simultaneously recovering sulfur dioxide to prepare sulfuric acid, reusing sulfuric acid for the acid leaching treatment, diluting the soluble glass by the use of a sodium carbonate solution, carrying out carborization to obtain white carbon black, and reusing the carbonating solution for iron-aluminium separation. The method provided by the invention has characteristics of wide application range of the raw material gangue, high comprehensive recovery rate, no output of by-products, less residue amount and the like, provides a novel technological process for high-efficiency recovery of ferro-silico-aluminum from gangue, and expands the ways of gangue application.

The invention relates to water treatment field, in particular to a process of advanced treatment and recycle of urban sewage, which adopts a membrane bioreactor and inverse penetration in combination. The invention takes secondary effluent of urban sewage treated by sewage plant or water of urban sewage being treated to meet the standard of secondary effluent as raw water; the raw water enters the membrane bioreactor MBR system for biochemical pretreatment to remove BOD, COD, SS, ammonia and nitrogen in the water to ensure that the water after treatment meets the quality requirement of reverse osmosis feed water; further water desalination is carried out through reverse osmosis system, and the needed recycle water can be obtained. By adopting MBR technology, removal rate of the main contamination COD can reach over 95 percent, the suspended matter and turbidity of the treated water are close to zero and the quality of the treated water is good and steady; according to process requirements, the water treated by the MBR system and the reverse osmosis system in sequence can be used as cooling water of cold rolled steel, after being blended according to certain proportion, thus realizing recycling of sewage.

The invention discloses an automobile transmission vibration analysis testing method and an automobile transmission vibration analysis testing device. The automobile transmission vibration analysis testing device comprises a base, a master control module, a frequency converter, a speed regulator, a driving motor, a load DC (direct current) motor, an automobile transmission, an industrial personal computer, a data acquisition card and a counting card. A power supply conversion module is adopted to supply power to other modules; the frequency converter is adopted to control and regulate the rotating speed of the driving motor; a load resistor and generator speed regulation box is adopted to regulate and control the torque of the load motor; the basic base and a shock pad are adopted to support; the shock pad is adopted to isolate vibration between the automobile transmission and the base; an elastic pin coupling is adopted to connect the automobile transmission with the motor and isolate vibration signals; and a vibration acceleration sensor is adopted to acquire the vibration signal of an automobile transmission shell. The testing method and the control device have high integration level, strong device expansibility and low cost and can be used for effectively simulating the basic operation of the automobile transmission, effectively acquiring the vibration and rotating speed signals of the automobile transmission and providing a simulated fault diagnosis analysis.

The invention belongs to the technical field of gas purification and provides a decarbonization solution and a decarbonization method due to the fact that CO2 content in recycle gas needs to be lowered when a novel high selective catalyst is adopted for synthesizing ethylene oxide / glycol. The solution is composed of potassium carbonate and an inorganic activating agent. Two-section absorption process of appropriate flow distribution and temperature control is adopted. Desorbing of the solution adopts novel transformation regeneration energy-saving technology, differential pressure is formed between two towers of a pressurization regeneration tower and a normal pressure regeneration tower by using a desorbing effect of an adjustable supersonic speed steam ejector on the normal pressure regeneration tower, mixed gas containing a large amount of water vapour is desorbed for gas stripping and regeneration for the pressurized regeneration tower. By means of the method, residue CO2 in the recycle gas after decarbonization is greatly reduced, and simultaneously solution reclaimed heat consumption is reduced by more than 30% compared with conventional potassium carbonate decarbonization process.

The invention discloses a three-hole parallel magnetic levitation vacuum tunnel structure. The structure comprises running tunnels on the two sides and a service tunnel on the middle. The running tunnels and the service tunnel are connected through a connection channel, the interiors of the running tunnels are vacuum environments, the bottoms of the running tunnels are in under-rail filling, a magnetic levitation rail beam is placed on the filling face, a magnetic levitation train runs on the magnetic levitation rail beam, the interior of the service tunnel is the normal pressure environment,the bottom of the service tunnel is in filling under equipment, equipment needed by magnetic levitation running is placed on the filling face, other spaces serve as evacuation channels, one end of theconnection channel communicates with the running tunnels, the other end of the connection channel communicates with the service tunnel, and a vacuum isolation wall and a vacuum isolation door are arranged on the connecting position of the communication channel and the running tunnels. The low-vacuum environment can be ensured, the ground space use can be reduced, adaptation to the terrain is high, the tunnel structure with good passenger evacuation, personal inspection and equipment arranging capacity is achieved, and meanwhile, practicability, safety and economy are all considered.

An operating platform system used for a high-rise building robot comprises suspension mechanisms and an aerial work platform. The suspension mechanisms are used for being fixedly arranged on the top of a building and responsible for the suspension work of the aerial work platform, and the aerial work platform is connected with the suspension mechanisms through suspension ropes and comprises a platform body, an elevator, a shock absorber and the hanging ropes. The platform body comprises a bottom plate, guardrails and a robot installation base.

The invention provides a wet type fine particle high-efficiency cyclone removal device including a cyclone cylinder, a cyclone washing plate, an atomizer, a liquid film spray nozzle, a demister, a filter, a variable frequency water pump, a liquid collecting pool, a PM concentration measuring instrument and a control signal sensor; the lower end of a cylinder body of the cyclone cylinder is provided with the liquid collecting pool and a liquid discharging port, the upper part of the cylinder body is provided with a flue gas inlet in a tangential manner, and the upper end part of the cylinder body is provided with a flue gas outlet; the cyclone washing plate, the atomizer and the liquid film spray nozzle are successively fixedly arranged at the inner cavity of the cylinder body from bottom to top; the demister is arranged on the upper part of the inner cavity of the cylinder body and is located below the flue gas outlet; a water outlet of the water pump is connected with a water inlet of the liquid film spray nozzle and the atomizer through pipelines. With use of atomizing and dust settling, cyclone plate washing, and liquid film dust control and adsorption, the cyclone separation device can remove fine particles with high-efficiency, and is stable and reliable in running. After flue gas is purified, no fog and water entrained phenomenon exists, and a device material has the properties of corrosion resistance, wear resistance and high-temperature resistance and has long service life.

The invention relates to a deep learning framework transplanting and optimizing method and system based on a target many-core. The method comprises the steps: in a transplanting process, transplantinga source code of a deep learning framework to a target many-core machine, modifying and compiling the framework according to a compiling instruction of the target many-core machine, and enabling theframework to meet the operation conditions of the target many-core machine; the acceleration optimization process comprises the steps that the framework is used for operating a functional model basedon deep learning on domestic many-cores, a target many-core performance analysis tool is used for analyzing codes, and confirmation and extraction of hotspot functions are achieved; analyzing and testing features and function parameters of the hotspot function; accelerating the hotspot function by using a parallel acceleration library; and determining an optimization strategy, finally improving the speed-up ratio of the framework on the premise of ensuring the correctness of the framework, and modifying and testing the compiled file of the deep learning framework according to the current master-slave core parallel code so as to realize the hybrid compilation and operation of the current master-slave core parallel code.

The invention relates to a kickboxing competition scoring system, which comprises an input device, a CPU (central processing unit) and an output device, wherein the input device, the CPU and the output device are mutually connected; the input device comprises a main keyboard with a plurality of keys, and the keys of the main keyboard comprise a scoring key, a warning key, numeric keys, a start key and an end key; the output device comprises a VGA (video graphics array) output interface, an audio output interface and an LED (light-emitting diode) output interface; the CPU is cured with special software programs and connected with a side judging apparatus subsystem by a connector; and the CPU is connected with a memory. Compared with the prior art, the kickboxing competition scoring system has the advantages that the system is quick in running speed and start-up; 2, the system subjected to restarting automatically restores to the state of competition before interruption so as to ensure the continuity of the competition; and 3, in the process of competition, the system can be separated from a computer and operate independently, and meets the operation conditions only by a computer monitor, a television or other display screens with VGA interfaces, therefore, the cost of the system is reduced, and the system is convenient to use.

The invention provides a double-enzyme co-immobilizing method and an immobilized enzyme prepared through the method and belongs to the field of bioengineering, and multiple immobilized enzymes with high catalysis efficiency and low cost can be obtained. The double-enzyme co-immobilizing method comprises the following steps: adding a calcium chloride solution into a buffer solution containing alpha-acetolacetate decearboxylase and proline endoprotease which are to be immobilized, enabling full reaction at set temperature, and centrifugally separating and washing to obtain the immobilized enzymes of nanoflower structures. The double-enzyme co-immobilizing method can be applied to beer production, in particular to the final filter stage of clear wine in a beer production process.

The invention discloses a multi-stage cold source swimming pool heat pump dehumidifier and a working method thereof. The multi-stage cold source swimming pool heat pump dehumidifier comprises an air preheater, two or more than two refrigerating circulation systems and an air heater, and the air preheater, the two refrigerating systems and the air heater are sequentially arranged in the air flow direction; in the more than two refrigerating circulation systems which are arranged in parallel, the first refrigerating system is provided with an evaporator and a condenser, and refrigerating or heatpump heating can be achieved; and the second system is provided with a first evaporator and two parallel condensers, and refrigerating dehumidifying, air temperature rising and pool water heating circulating can be achieved. According to the multi-stage cold source swimming pool heat pump dehumidifier and the working method thereof, air can be treated step by step, various energy sources with different kinds of quality are fully utilized, and the purpose of improving the comprehensive energy efficiency is achieved; meanwhile, unit condensation heat is recycled and reutilized, the air feedingstate is adjusted and improved, and the pool hall temperature and humidity and the pool water temperature are adjusted; and in addition, air exhaust energy is recycled and used for lowering the unit condensation temperature or increasing the evaporation temperature, and the energy efficiency is improved.

The invention discloses a self-locking flow regulating needle valve. The self-locking flow regulating needle valve comprises a valve seat, a guide base, a valve rod base and an upper cover, wherein achoke plug is fixedly connected in the upper cover; the upper cover is fixedly connected in the valve rod base; the valve rod base is fixedly connected in the guide base; the guide base is fixedly connected in the valve seat; the lower end of the valve seat is provided with an inlet; the inlet communicates with a fluid inlet; a fluid outlet is transversely formed in the side surface of the valve seat; the upper end of the valve rod is movably blocked in the upper cover and the valve rod base; the valve element is in threaded connection to the lower end of the valve rod; the outer edge of the valve element is blocked to the lower end of the guide base; the lower end of the valve element is equipped with the needle valve; and the needle valve is movably blocked to the lower-end inlet of thevalve seat. The self-locking flow regulating needle valve has the advantages of being micro in regulation, good in sealing effect, capable of being self-locked and the like.

The present invention relates to a control method for operation units. The method comprises: pre-determining a relative current value, and using the current value as a reference; then calculating a sum of current values of the practically running operation units according to a target frequency and a current temperature, comparing the sum of the current values with the relative current value used as the reference, and if the sum of the current values is smaller than the relative current value, using the target frequency corresponding to the sum of the current values as a candidate running frequency of the currently running operation units; and when the largest candidate running frequency is determined, setting the largest candidate running frequency as the running frequency of the currently running operation units. Namely, for a user, within a range of the relative current value, not only can running conditions of the operation units be met, so that the efficiency of the operation units is improved while current suppression is realized, but also running efficacy of the operation units cannot be suppressed, and thus, user experience also can be improved. Furthermore, the present invention provides a control system for the operation units.

The invention belongs to the technical field of petrochemical industry and discloses a process for efficiently recovering reforming gas energy in the hydrocarbon steam reforming hydrogen production process. According to the process, a reforming gas turbo expander is arranged between the outlet of a reforming furnace and the inlet of a waste heat boiler, so thate pressure energy and high-temperature heat energy of primary reforming gas are recovered to generate mechanical power or generate electricity or drive other power equipment (such as a raw natural gas compressor), the device output energy is increased and the device energy consumption is reduced under the condition of not influencing the yield and the purity of a hydrogen product, energy upgraded utilization is realized and significant economic benefit is achieved.

The invention discloses a physical method-based circular processing technology for bottle washing water and a device thereof. The technology and the device include four-level filtering: primary filtering for intercepting macroscopic impurities, self-cleaning filtering in filtering precision of 100mum, secondary filtering in filtering precision of 20mum and low-pressure ultra-filtration in filtering precision of 0.01mum. The technology and the device also include a back-flushing component and a CIP cleaning component. The physical method-based circular processing technology for bottle washing water is different from the traditional water purifying technology; the specific grading filtering method is adopted by the technology; the chemical agents required by the traditional technology are not added in the running process, so that the water can be more extremely recycled; four-level filtering measures are designed for the technology and different filtering precisions are arranged for the four-level filtering measures; especially, the filtering precisions from the second-level filtering to the fourth-level filtering are the optimal parameters acquired after the experiment; and a physical treatment technology is creatively utilized to clean the water and the sewage emission is reduced.

The invention discloses an unpowered non-force self-flat-pressing oil groove integrated flotation seal device. Baffle rings are mounted on the upper ring face and the lower ring face of a sectioning seat ring with a seat ring flange and an occlusal face, upper integrated rectangular groove rings internally provided with 4 to 16 sectioning floating seal bodies are fixed to a baffle ring inner sideupper ring face, the 4 to 16 sectioning floating seal bodies are mounted inside, lower integrated rectangular groove rings with rectangular groove lower rings provided with oil filling holes are fixedto a baffle ring inner side lower ring face, an air inlet hole in a vertical ring face communicates with an air filter with a flat pressing hole and an air opening and internally provided with an airfilter body through a connecting pipe and a connecting hose, a flat pressing through hole in the lower ring face communicates with a shell with a flat pressing hole, provided with a flat pressing opening in the upper portion, and internally provided with a multi-layer oil mist filter body, a flow guide frame and an oil collection box through a flat pressing pipe and a connecting hose, the sectioning seat ring forms a whole circle through the occlusal face via occlusal bolts, through the seat ring flange, the occlusal bolts are used for fixing the whole sectioning seat ring to an oil groove, and the device can be widely applied to the field of hydro-generators and the like.

The invention belongs to the technical field of gas purification and provides a decarbonization solution and a decarbonization method due to the fact that CO2 content in recycle gas needs to be lowered when a novel high selective catalyst is adopted for synthesizing ethylene oxide / glycol. The solution is composed of potassium carbonate and an inorganic activating agent. Two-section absorption process of appropriate flow distribution and temperature control is adopted. Desorbing of the solution adopts novel transformation regeneration energy-saving technology, differential pressure is formed between two towers of a pressurization regeneration tower and a normal pressure regeneration tower by using a desorbing effect of an adjustable supersonic speed steam ejector on the normal pressure regeneration tower, mixed gas containing a large amount of water vapour is desorbed for gas stripping and regeneration for the pressurized regeneration tower. By means of the method, residue CO2 in the recycle gas after decarbonization is greatly reduced, and simultaneously solution reclaimed heat consumption is reduced by more than 30% compared with conventional potassium carbonate decarbonization process.

The invention provides a variable ring width hysteresis current control method based on a timer and a circuit for realizing the method. A standard ring width option list and a standard ring width real-time adjustment form are stored, the optimal standard ring width is chosen from the stored forms according to the relation of an actual measurement current deviation, actual currents and system rated currents, PWM signal output is generated according to the current deviation on the basis of the optimal standard ring width, and switching-on and switching-off of an IGBT power tube are controlled. The variable ring width hysteresis current control method based on the timer has the obvious advantages of lowering switching loss, increasing the current tracing speed and improving current quality.

The invention discloses a tail low-resistance heat exchange device for a micro-positive pressure oil and gas fired boiler, which is characterized in that: exhaust gas discharged by the tail of the micro-positive pressure oil and gas fired boiler enters an inlet smoke box through a straight flue; a heat exchange component in the heat exchange device between the inlet smoke box and an outlet smoke box is a screwed pipe; the top of the heat exchange device is provided with an oxygen removing tower which is connected with an inlet water spray pipe; and the top of the oxygen removing tower is provided with a steam escape port. The tail low-resistance heat exchange device for the micro-positive pressure oil and gas fired boiler has the advantages of greatly improving the thermal efficiency of the micro-positive pressure boiler, reducing the manufacturing cost of the product, and ensuring stable and reliable running.

The invention discloses a comprehensive extraction method of ferro-silico-aluminum in gangue, comprising the following steps of: using gangue as a raw material, crushing, grinding, activating, carrying out acid leaching, filtering, neutralizing free acid in the acid leaching filtered solution by the use of active slag, filtering to obtain a neutralized acid leaching solution, adding a sodium carbonate solution into the neutralized acid leaching solution, adjusting pH value, separating iron and aluminium to obtain hydrous iron oxide, aluminium hydroxide and a by-product sodium sulphate, adding sodium sulphate and coke into the acid leaching slag which has undergone acid leaching and filtration, carrying out a high-temperature melt reaction to recover silicon so as to prepare soluble glass, simultaneously recovering sulfur dioxide to prepare sulfuric acid, reusing sulfuric acid for the acid leaching treatment, diluting the soluble glass by the use of a sodium carbonate solution, carrying out carborization to obtain white carbon black, and reusing the carbonating solution for iron-aluminium separation. The method provided by the invention has characteristics of wide application range of the raw material gangue, high comprehensive recovery rate, no output of by-products, less residue amount and the like, provides a novel technological process for high-efficiency recovery of ferro-silico-aluminum from gangue, and expands the ways of gangue application.

The invention puts forward a reliable operation method of a drilling machine electronic control system in the low-temperature environment. A dehumidification and heating device is arranged in a control room of the drilling machine electronic control system; a heater with a temperature control function is added at the position of an air conditioner outdoor unit; an electrically controlled louver type exhaust fan is additionally installed at the upper end of a heat dissipation air outlet of the outdoor unit, a temperature control device is additionally installed at the air conditioner outdoor unit, a temperature control signal has access to a power supply control loop of the louver type exhaust fan, and the temperature control device is in linkage control with the louver type exhaust fan; and a pressure detecting device is additionally installed on an air pressure pipeline connected with the air conditioner outer unit, the measured pressure detection signal has access to a control loop of an outer unit fan, and the pressure detecting device is in linkage control with the outer unit fan. The reliable operation method has the beneficial effects that normal operation of the drilling machine electronic control system is ensured under the low-temperature environment condition, and the materials needed for refitting are easily available and easy to assemble.

The invention discloses a protection device for power maintenance. The device comprises a device shell, a rubber bottom plate is mounted at the bottom in the device shell; a sliding door is mounted ata rear part of the device shell; a first workbench is mounted at the top of a left side of the device shell, a second workbench is mounted at the top of a right side of the device shell; a first fixed block is mounted below a right side of the first worktable; a second fixed block is mounted below a left side of the second worktable; a safety belt hook is mounted at the bottom of each of the first fixed block and the second fixed block; a right side of the first fixed block and a left side of the second fixing block are each provided with a grip. The device has the advantages that various operation conditions can be met, the protectiveness of workers is improved, technical communication with technicians can be conducted in time during maintenance, the maintenance work efficiency is greatly improved, the practicability is high, and the device is suitable for being used and popularized in a large range.

A DC voltage coordination control method is applied to a multi-terminal VSC-HVDC power transmission system or a VSC-HVDC power grid system. When a lower-level control is used in the active power control mode, the active power reference value of the converter is generated according to the converter DC voltage and the converter DC voltage active power curve; it also includes an upper-level control to adjust the control mode and active power setting value of the lower-level control to ensure the steady-state performance of the system. This method has low dependence on communication, avoids the problem that the fixed slope and margin cannot meet all operating conditions, and is suitable for large-scale VSC-HVDC systems, and has scalability.

The invention puts forward a reliable operation method of a drilling machine electronic control system in the low-temperature environment. A dehumidification and heating device is arranged in a control room of the drilling machine electronic control system; a heater with a temperature control function is added at the position of an air conditioner outdoor unit; an electrically controlled louver type exhaust fan is additionally installed at the upper end of a heat dissipation air outlet of the outdoor unit, a temperature control device is additionally installed at the air conditioner outdoor unit, a temperature control signal has access to a power supply control loop of the louver type exhaust fan, and the temperature control device is in linkage control with the louver type exhaust fan; and a pressure detecting device is additionally installed on an air pressure pipeline connected with the air conditioner outer unit, the measured pressure detection signal has access to a control loop of an outer unit fan, and the pressure detecting device is in linkage control with the outer unit fan. The reliable operation method has the beneficial effects that normal operation of the drilling machine electronic control system is ensured under the low-temperature environment condition, and the materials needed for refitting are easily available and easy to assemble.

The invention discloses an automobile transmission vibration analysis testing method and an automobile transmission vibration analysis testing device. The automobile transmission vibration analysis testing device comprises a base, a master control module, a frequency converter, a speed regulator, a driving motor, a load DC (direct current) motor, an automobile transmission, an industrial personal computer, a data acquisition card and a counting card. A power supply conversion module is adopted to supply power to other modules; the frequency converter is adopted to control and regulate the rotating speed of the driving motor; a load resistor and generator speed regulation box is adopted to regulate and control the torque of the load motor; the basic base and a shock pad are adopted to support; the shock pad is adopted to isolate vibration between the automobile transmission and the base; an elastic pin coupling is adopted to connect the automobile transmission with the motor and isolate vibration signals; and a vibration acceleration sensor is adopted to acquire the vibration signal of an automobile transmission shell. The testing method and the control device have high integration level, strong device expansibility and low cost and can be used for effectively simulating the basic operation of the automobile transmission, effectively acquiring the vibration and rotating speed signals of the automobile transmission and providing a simulated fault diagnosis analysis.

The invention relates to a No.0 high-pressure heater optimization control system based on multi-data judgment. The No.0 high-pressure heater optimization control system comprises four control levels, namely a heating pipe control level, an environmental protection control level, an economic control level and a primary frequency modulation control level. Full-process automatic commissioning of a No.0 high-pressure heater after unit starting and grid connection is realized through the four control levels. According to thermal control measurement values such as 0 extraction pressure, 0 extraction temperature, outlet temperature of the No.0 high-pressure heater, upper and lower wall temperatures of a 0 extraction pipeline, steam inlet pressure of the No.0 high-pressure heater, unit load and a primary frequency modulation slip signal, optimization of heating pipe control, environmental protection control, economic control and primary frequency modulation control of the No.0 high-pressure heater is realized. Thus, the outlet smoke temperature of a coal economizer is improved, the environmental protection level of a unit is greatly improved, and the economic performance of the unit is improved to the maximum extent. The frequency modulation load basically meets the small disturbance requirement, so that different control targets are achieved at different operation stages of the unit of the No.0 high-pressure heater, and the maximum economic value of the unit is achieved from the three aspects of energy conservation, environmental protection and frequency modulation.

The invention relates to a method for removing water from an ionic liquid alcoholic solution. The method comprises the following steps: S1, adding an additive into an ionic liquid alcoholic solution for adjustment to obtain an adjusted ionic liquid alcoholic solution; S2, enabling the adjusted ionic liquid alcoholic solution to pass through a pervaporation unit to obtain a dehydrated ionic liquid alcoholic solution; and S3, heating the dehydrated ionic liquid alcoholic solution, and recovering the additive in the ionic liquid alcoholic solution. According to the method disclosed by the invention, the acidity in the system is greatly reduced by adding the additive into the acidic ionic liquid alcoholic solution, so that the system does not damage the pervaporation membrane, and the operation conditions of the conventional pervaporation membrane are met; the whole water removal process can be completed at low temperature, so that the energy consumption of the whole process is greatly reduced; and the whole process is simple and easy to be continuous, and the obtained treated final product can directly enter esterification, ester exchange and other reaction units to realize direct reuse of the ionic liquid.

The invention discloses a tail low-resistance heat exchange device for a micro-positive pressure oil and gas fired boiler, which is characterized in that: exhaust gas discharged by the tail of the micro-positive pressure oil and gas fired boiler enters an inlet smoke box through a straight flue; a heat exchange component in the heat exchange device between the inlet smoke box and an outlet smoke box is a screwed pipe; the top of the heat exchange device is provided with an oxygen removing tower which is connected with an inlet water spray pipe; and the top of the oxygen removing tower is provided with a steam escape port. The tail low-resistance heat exchange device for the micro-positive pressure oil and gas fired boiler has the advantages of greatly improving the thermal efficiency of the micro-positive pressure boiler, reducing the manufacturing cost of the product, and ensuring stable and reliable running.

A Buchholz relay (1) for comprising a support frame (2) in contact with the oil, drive means (3) coupled to the support frame (2), switching means (4), operatively connected with the drive means (3) and suitable for an alarm circuit and / or a shutdown circuit of the electrical equipment, a regulation valve (5) of the oil flow, coupled to the support frame (2), suitable to be affected by the oil flow in order to define a first position in which it disables the shutdown circuit and a second position in which, if the oil discharge exceeds a certain threshold, it enables the shutdown circuit. The Buchholz relay (1) also includes biasing means associated with the support frame (2) and with the valve (5) to keep the latter in the first position.

A DC voltage coordination control method is applied to a multi-terminal VSC-HVDC power transmission system or a VSC-HVDC power grid system. When a lower-level control is used in the active power control mode, the active power reference value of the converter is generated according to the converter DC voltage and the converter DC voltage active power curve; it also includes an upper-level control to adjust the control mode and active power setting value of the lower-level control to ensure the steady-state performance of the system. This method has low dependence on communication, avoids the problem that the fixed slope and margin cannot meet all operating conditions, and is suitable for large-scale VSC-HVDC systems, and has scalability.