1217results about How to "Guarantee job stability" patented technology

The invention discloses a power battery temperature management method of an electric automobile. The power battery temperature management method comprises a battery temperature deducing method, a battery temperature optimum work region regulating method, a battery overtemperature prevention management method and a battery undertemperature prevention management method. A management system determines the battery work mode according to the charging and discharging current condition of a battery; the battery temperature change trend of the battery after heat radiation and heating measures are used or when the heat radiation and heating measures are not used is calculated according to the battery heat radiation and heating strategies; the battery heat radiation and heating strategies are selected, so that the battery temperature is maintained in the optimum work region or is similar to the optimum work region. The power battery temperature management method of the electric automobile has the following characteristics that the battery temperature is maintained in the optimum work range to the greatest degree; the use strategies and the heat radiation and heating strategies of the battery are systematically combined, so that the work stability of the battery is guaranteed; except for a special condition that a user cannot realize charging, the condition of automobile charging incapability due to too low temperature can be avoided.

The invention provides a hole expanding drill bit. The hole expanding drill bit comprises a drilling rod, a plurality of cutter bodies, hole expanding wings, lower blades, an expanding oil cylinder, an upper blade, a slurry tube and a hydraulic oil tube assembly, wherein the cutter bodies are fixed on the blades; the lower blade is horizontally uniformly distributed and fixed on the peripheral surface of the lower part of the drilling rod in a radial form; the hole expanding wings are positioned above the lower blade and symmetrically formed along the drilling rod in the radial direction; an oscillating rod is mounted on a pin seat on the peripheral surface of the drilling rod through a hinge pin pivotal shaft, and the end of the oscillating rod is positioned into a groove in a cylinder barrel; the slurry tube is positioned in holes of a piston and a piston hole of the expanding oil cylinder. According to the hole expanding drill bit, the combined drilling and excavating structure is adopted; the hole expanding wings can be opened by operating the expanding oil cylinder while expanding the bottom or hole, besides the function of drilling and excavating general piles with the same section, so that the pile end of a bearing file and the section area of a pile body can be increased; the drill bit can be used for building various bottom expanding piles and calabash piles, and has the characteristics of being high in single pile bearing capacity, ensuring the pile diameter, and being convenient to construct, stable and reliable to work, and long in service life.

The invention relates to a two-component sealing adhesive with low viscosity and high thermal conductivity and a preparation method thereof. The two-component sealing adhesive consists of a component A and a component B in a weight ratio of 100:80-100:125, wherein the component A comprises the following raw materials by weight percent: 40.00%-90.00% of thermal conductive powder, 4.50%-50.00% of low-viscosity liquid silicone oil, 0.50%-10.00% of silicane curing agent and 0.00-5.00% of toner; and the component B comprises the following raw materials by weight percent: 40.00%-90.00% of thermal conductive material, 9.50%-54.00% of low-viscosity liquid silicone oil, 0.04%-1.00% of catalyst and 0.00-5.00% of toner. The preparation method comprises the following steps: weighting all the raw materials according to the weight persentages to prepare the component A and the component B; and when in use, mixing the component A and the component B evenly in a weight ratio of 100:80-100:125, and curing to obtain the sealing adhesive of the invention.

The invention relates to a wheelchair and a method thereof. The wheelchair comprises a chair frame and a front lifting device and a rear lifting device which are arranged below the chair frame; the chair frame comprises a chair seat, a cushion part connected to the chair seat in a sliding mode, a pedal part rotatably connected to the front end of the cushion part, a first driving component used for driving the cushion part to slide and a second driving component used for driving the pedal part to rotate; the pedal part is provided with a telescopic end and a driving wheel set arranged at the front end of the telescopic end; the front lifting device is provided with a left front wheel set and a right front wheel set; the driving wheel set, the left front wheel set and the right front wheel set are driven through a hub motor; the chair seat is provided with a front driving component used for driving the front lifting device to rise and fall and a rear driving component used for driving the rear lifting device to rise and fall; the front driving component and the rear driving component are fixed to the chair frame. According to the wheel chair and the method thereof, the requirements of a user for lying and getting on or off the wheelchair can be met.

The embodiment of the invention discloses an insertion and extraction force testing device, which comprises an upright, a force sensor, an upper fixture, a lower fixture, a driving unit and a control unit, wherein the control unit comprises a data extraction module, a touch display screen and a control module; the data extraction module is connected with the force sensor for extracting testing information of the force sensor; the touch display screen is used for displaying a control interface and inputting a control instruction, and connected with the data extraction module for displaying testing data obtained by the data extraction module in real time; and the control module is connected with the driving unit for controlling the driving unit to run according to the control instruction. The insertion and extraction force testing device is simple in structure, easy and simple to operate, high in stability, and low in use cost and manufacturing cost.

The invention discloses an anti-drunk driving vehicle-mounted system capable of ensuring driver uniqueness. The vehicle-mounted system comprises an alcohol detector, an A / D converter and a starting controller; the alcohol detector is connected with the A / D converter; the vehicle-mounted system also comprises a face identification system, a CCD sensor circuit, an air valve and a central processor,wherein the face identification system is connected with the CCD sensor circuit and the central processor respectively; the central processor is connected with the A / D converter, the starting controller and the air valve respectively; the air valve comprises an air port; and the alcohol detector is arranged at the position close to the air port. The vehicle-mounted system uses an alcohol detection system as main detection and uses the face identification system as auxiliary monitoring, combines the two systems to monitor the driver in the whole course at the same time of avoiding drunk driving, can carry out uniqueness control for the driver, and is used for preventing the corrupt actions that the driver bribes others or stops the vehicle in the middle way to change others to drive the vehicle.

The invention relates to a vacuum belt press filter, comprising a rack, a vacuum filtration assembly, a press assembly and a filtration belt assembly, wherein the filtration belt assembly comprises an upper filtration belt, a lower filtration belt, and a cleaning device A and a cleaning device B which are used for respectively cleaning the upper filtration belt and the lower filtration belt; the cleaning device B comprises a front guide roller and a rear guide roller on the motion direction of the lower filtration belt, the front guide roller is arranged on the upper face the lower filtration belt, closely contacts the lower filtration belt and enables the lower filtration belt to form a V shape, the rear guide roller is arranged on the lower face of the lower filtration belt and is provided with a plurality of pinpricks, the size of each pinprick is matched with the size of a filtration pore of the filtration belt, and the rear guide roller contacts with the lower filtration belt by the pinpricks; and the cleaning device B is provided with a plurality of spray heads, and the spray heads are distributed on the upper face and the lower face of the lower filtration belt. The vacuum belt press filter of the invention has the advantage of favorable cleaning effect of the filtration belts, and belongs to the technical field of press machines.

The invention relates to a lean oil direct injection and mixing low-pollution combustion chamber. The lean oil direct injection and mixing low-pollution combustion chamber is composed of a diffuser, acombustion chamber outer case, a combustion chamber inner case, a combustion chamber head, a flame tube outer wall and a flame tube inner wall, wherein combustion air all enters a flame tube from thecombustion chamber head; the combustion chamber head is divided into an on-duty grade and a main combustion grade through a grading and partitioning combustion strategy; the on-duty grade and the main combustion grade both adopt a direct injection and mixing combustion method, the phenomena of spontaneous combustion and tempering are effectively avoided, and the risk of occurrence of oscillationcombustion is lowered; the lean oil direct injection and mixing low-pollution combustion chamber only works in an on-duty grade mode under an idling rating state, the designed partial equivalence ratio is higher, and the work stability of the combustion chamber is guaranteed; and with the increase of the work state of the combustion chamber, the main combustion grade is opened gradually, the maincombustion grade and the on-duty grade work simultaneously under a large state, the designed combustion area average equivalence ratio is lower, the average temperature of the combustion area is effectively lowered, and therefore the generation quantity of pollutants is lowered.

The invention provides an adaptive control method for an excavator, which is characterized by comprising the following steps of: A, arranging an adaptive control system on the excavator; B, performing parameter acquisition; and C, controlling a priority electromagnetic valve by using a controller, wherein the step C comprises the following sub-steps that: C1, the controller calculates the proportions of movable arm action, shovel loader action, loader bar action and rotation action in the whole operation process respectively; and C2, the controller compares the proportion of the movable arm action, the shovel loader action, the loader bar action and the rotation action in the whole operation process with a set value respectively, and opens the priority electromagnetic valve according to comparison results. In the method, a movable arm pressure sensor, a loader bar pressure sensor, a shovel loader pressure sensor and a rotation pressure sensor sense current working conditions to automatically adjust the working state of the excavator.

The present invention relates to a clamp ring type torque sensor for obtaining drive shaft torque. Said sensor adopts semi-ring design, and said sensor can be quickly clamp-mounted on the drive shaft only by utilizing holt and nut. When the torque is received by drive shaft, the shearing deformation which is directly proportional to the torque on the drive shaft can be transferred to the sensor elastic body on which a strain foil is stuck so as to obtain the torque signal of said drive shaft. Said invention also provides the design method of said sensor elastic body.

The invention provides an ultrasonic imaging method and device for an axial flow field of fluid in a pipeline. The method comprises the following steps: distributing a plurality of ultrasonic transducers on the two cross sections at the upstream and the downstream, and detecting the axial flow field by using a tone channel network woven by the transducers; stimulating each transducer in sequence, electronically scanning and collecting ultrasonic signals transmitted by fair current and counter current of each tone channel; calculating average line flow velocity, and obtaining projection integration of the axial flow field on each tone channel; parallelly dividing the tone channels, and subdividing projection data of each tone channel group in an interval manner; using the chromatography imaging algorithm, rebuilding the axial flow field by using the subdivided projection data, and outputting and displaying the axial flow field. The device comprises a flow field detection pipe segment, an ultrasonic signal stimulation and collection module, a tone channel line flow velocity measuring module, an axial flow field reconstruction module and an output and display module. According to the device and the method provided by the invention, quick and accurate no-blind zone detection of the axial flow field on the cross sections of the pipeline can be realized, so that high-precision two-dimensional rebuilding of the axial flow field can be realized accordingly.

The invention relates to a liquefaction system and a liquefaction method for NG (Natural Gas). The system comprises a cold box, a supply pipe for supplying the NG to the cold box, a No.1 refrigerant liquefaction subsystem, a No.2 refrigerant liquefaction subsystem, a No.1 refrigerant cooling subsystem, a No.2 refrigerant cooling subsystem, a heavy hydrocarbon separation tank which is used for conducting gas-liquid separation to liquid heavy hydrocarbon and gas light hydrocarbon, and an LNG (Liquefied Natural Gas) storage tank which is used for storing LNG obtained through liquefaction, wherein the cold box comprises an NG precooling passage which is connected with the heavy hydrocarbon separation tank and is used for supplying the NG; an NG deep cooling passage which is connected with the LNG storage tank and is used for supplying the gas light hydrocarbon; a No.1 refrigerant precooling passage and a No.2 refrigerant precooling passage which are used for respectively supplying and cooling high-pressure No.1 refrigerant and high-pressure No.2 refrigerant which are respectively supplied by the No.1 refrigerant liquefaction subsystem the No.2 refrigerant liquefaction subsystem, and are used for respectively supplying the cooled high-pressure No.1 refrigerant and the cooled high-pressure No.2 refrigerant to the No.1 refrigerant cooling subsystem and the No.2 refrigerant cooling subsystem; and a No.1 refrigerant cooling passage and a No.2 refrigerant cooling passage which are used for respectively supplying low-temperature No.1 refrigerant and low-temperature No.2 refrigerant which are respectively supplied by the No.1 refrigerant cooling subsystem and the No.2 refrigerant cooling subsystem to cool the NG, high-temperature No.1 refrigerant and high-temperature No.2 refrigerant. By adopting the technical scheme, the complexity and the energy consumption of the system can be reduced.

The invention provides a hollow anode for a plasma thruster of a cusped magnetic field, and relates to a plasma thruster of a cusped magnetic field. By the hollow anode for the plasma thruster of the cusped magnetic field, the problems that a permanent magnet is demagnetized and the service life of a thrust is shortened due to the fact that an anode of the existing thruster of a cusped magnetic field is over hot are solved. The ionization rate of the thruster is increased, and the performance of the thruster is further improved. The hollow anode for the plasma thruster of the cusped magnetic field comprises a gas distributor, a buffering cavity and a ceramic sleeve, wherein a gas supply piece comprises a guide tube and a cavity; and the gas distributor comprises the gas supply piece and a distributor bottom plate. The hollow anode for the plasma thruster of the cusped magnetic field is used in the field of plasma thrusters of the cusped magnetic field.

The invention discloses an air conditioner used in a high-temperature environment and a control method. The air conditioner comprises a compressor, a condenser, a first throttling valve, an evaporator, a refrigerant circulating pipe and a liquid refrigerant spraying loop pipe, wherein the compressor, the condenser, the first throttling valve and the evaporator are sequentially connected with one another end to end through a refrigerant circulating pipe, so that a closed refrigerant circulating channel is formed; one end of the liquid refrigerant spraying loop pipe is communicated with a refrigerant circulating pipe between the condenser and the throttling valve; and the other end of the liquid refrigerant spraying loop pipe is communicated with a refrigerant circulating pipe between the evaporator and the compressor. The liquid refrigerant spraying loop pipe is used for mixing liquid refrigerant flowing from the condenser with gas refrigerant evaporated by the evaporator so as to reduce the air suction temperature of the compressor. Along with reduction of the air suction temperature of the compressor, the temperature of a motor in the compressor is reduced, the air exhaust temperature of the compressor is also reduced, so that the compressor can stably work in the high-temperature environment, and the refrigerating efficiency of the air conditioner is greatly improved.

The invention discloses a crawler chassis which comprises an underframe, two crawler frames and two connecting crossbeams, wherein the two crawler frames are symmetrically arranged at the right side and the left side of the underframe; the two connecting crossbeams are symmetrically arranged at the front side and the rear side of the underframe; the ends of the right side and the left side of the two connecting crossbeams are respectively connected with the crawler frames at the right side and the left side; the front connecting crossbeam is provided with an auxiliary seat extending backward, and the rear connecting crossbeam is provided with an auxiliary seat extending forward; and the auxiliary seats on the two connecting crossbeams are detachably and fixedly connected with the underframe. The crawler chassis meets the design requirements through the length of the auxiliary seats and can meet the requirement of external size for transportation while guaranteeing working stability, thereby greatly improving the stress conditions of all parts of the crawler chassis and enhancing the rigidity of the chassis. In addition, the external size and the weight of the underframe are effectively reduced to further facilitate transportation and installation of a whole machine. On the basis, the invention also discloses a crawler crane with the chassis.

The present invention relates to operational equipment, and provides one kind of multifunctional orthopedic operation equipment and its automatic control method. The structure of the multifunctional orthopedic operation equipment includes one system unit providing power source and automatic control, one high speed motor mechanism for driving and recognizing tool handles, at least two kinds of tool handles driven with the high speed motor mechanism to produce different motions, and at least two kinds of tool heads. The other important structure has recognizer set on the motor mechanism and corresponding recognized units in different tool handles; and the recognizer, the recognized units, cable, the system unit and the motor mechanism constitute the automatic control system.

The invention discloses a heat radiation structure of a mobile terminal. The heat radiation structure comprises an installation bracket, wherein a mainboard heat radiation region and a camera shooting heat radiation region are arranged on the installation bracket in parallel, the mainboard heat radiation region is used for controlling temperature rise of a mainboard module, the camera shooting heat radiation region is used for controlling temperature rise of a camera module, the mainboard heat radiation region adjoins to one side of the mainboard module, the camera shooting heat radiation region is arranged on one side, away from the camera module, of the mainboard heat radiation region. According to the mobile terminal and the heat radiation structure thereof, the camera shooting heat radiation region used for controlling temperature rise of the camera module is arranged in a region outside the mainboard module and the camera module, so that the heat of the camera module is isolated from that of the mainboard module, and the heat of the mainboard module and the camera module is prevented from interactively affecting the heat radiation efficiency of the two modules even normal operation of the two modules, thereby ensuring heat radiation efficiency and stable operation of the mainboard module and the camera module simultaneously.

A pixel driving method disclosed by the present invention comprises the steps of detecting the display mode of an LCD at a current frame; when the current frame is detected to be in a non-heavy load picture mode, using a processing unit to send a first frequency signal to a sequential control circuit; when the current frame is detected to be in a heavy load picture mode, using the processing unit to send a second frequency signal to the sequential control circuit; using the sequential control circuit to receive the first frequency signal and output a sequential control signal with a first working frequency at the next frame, or using the sequential control circuit to receive the second frequency signal and output the sequential control signal with a second working frequency at the next frame, wherein the first working frequency is higher than the second working frequency; using a data drive circuit and a scanning drive circuit to receive the sequential control signal and then drive the pixel electrodes to work. According to the present invention, the heating problem of the data drive circuit and the problem that the temperatures of the equipment rise are relieved, the working stability of the LCD is kept, and the LCD is prevented from being damaged.

The invention discloses an isolation type non-woven fabric textile winding machine which belongs to the technical field of textile winding. A cooling fan is arranged at the top of a fixed bracket; anupper flattening roller and a lower flattening roller are arranged at the top of a first bracket in sequence from top to bottom; a tensioning roller is arranged at the top of a third bracket; the tensioning roller is connected onto the third bracket through a second connecting shaft; a second through hole is formed in the top of a side wall of a second bracket; a second fixed block is arranged atthe top of the second through hole; a second rigid spring is arranged at the bottom of the second fixed block; a third connecting shaft is provided with a tracking roller; six groups of winding rollers with the same structure are arranged below the tracking roller; the winding rollers are connected with a connecting frame through a fourth connecting shaft; a ratchet wheel mechanism which is matched with a mounting groove is arranged at the left end of a fifth connecting shaft. The winding machine disclosed by the invention is reasonable in structural design and high in automation degree; simple and convenient textile winding work can be ensured and the winding effect of the fabric is remarkable.

The invention discloses a hydraulic control mechanism for vanes. The hydraulic control mechanism for the vanes solves the problem that vanes can still extend to the outside of a rotor when the existing common vane pump does not work, so that the energy consumption of the vane pump is large. The vane pump structurally comprises a shell, a stator and a rotor, wherein the rotor is arranged in the stator in a rotatable mode, a plurality of vane grooves are radially arranged in the rotor, the vane grooves are internally provided with the vanes in a sliding way, and the vanes can partially extend out of the radial outside of the rotor, or retract into the rotor. A cavity is formed between the rotor and the stator, and is provided with a fluid suction zone, a fluid compression zone and a vane retraction zone, the shell is internally provided with a chamber communicated with the cavity, and the chamber is communicated with the outside through a fluid inlet and a fluid outlet. When the rotor is required to idle, pressure fluid is introduced into the chamber so as to enable the vanes to stably retract into the rotor.

The invention discloses a display substrate and a preparation method therefor and a display panel. The display substrate comprises a substrate, wherein a thin film transistor and a light emitting device are formed on the substrate; the thin film transistor comprises an active layer, a source and a drain; an interlayer insulating layer is formed between the active layer and the source and between the active layer and the drain; a first via hole and a second via hole are formed in the interlayer insulating layer; the light emitting device is positioned in the first via hole; and the drain is connected with the positive electrode of the light emitting device through the second via hole. Compared with the prior art, by virtue of the technical scheme disclosed in the invention, a light emittingelement can be arranged in the first via hole in the interlayer insulating layer by changing the relative position between the thin film transistor and the light emitting element, so that the light emitting element and the thin film transistor can be positioned on the same height position of the substrate basically, thereby avoiding irradiation of the light from the light emitting element on theactive layer in the thin film transistor, and further ensuring working stability of the thin film transistor.

The invention discloses an indoor environment control unit and a building environment control system. The indoor environment control unit comprises an air inflow channel, an exhaust channel, a heat exchange device and a first air return control valve. The air inflow channel comprises a first air inlet communicated with the outside and a first air outlet communicated with the inside. The exhaust channel comprises a second air inlet communicated with the inside and a second air outlet communicated with the outside. The heat exchange device comprises a heat exchange air inflow channel located in the air inflow channel and a heat exchange exhaust channel located in the exhaust channel, the heat exchange air inflow channel is provided with a heat exchange inflow air outlet and a heat exchange inflow air inlet control valve, and the heat exchange exhaust channel is provided with a heat exchange exhaust air outlet and an exhaust air inlet control valve. The first air return control valve is used for making the exhaust channel and the air inflow channel communicated, and making air flow into the heat exchange air inflow channel from the exhaust channel through the heat exchange inflow air inlet control valve when the heat exchange inflow air inlet control valve is switched on. The indoor environment control unit and the building environment control system can adapt to low-temperature environments, and the frosting risk of the unit can be effectively reduced.

The invention discloses a methanol water reforming hydrogen production machine and a hydrogen production method thereof. The methanol water reforming hydrogen production machine comprises a methanol water storage container, a delivery pump, a frequency converter, a heat exchanger and a reformer, wherein the frequency converter is used for converting a low-frequency voltage or a direct current voltage into a high-frequency voltage required for an electromagnetic coil of an electromagnetic heater, the frequency converter is provided with a liquid cooling radiator, and a methanol water raw material flows through the liquid cooling radiator in the pumping process of the delivery pump, so that heat generated by the frequency converter is taken away by the methanol water raw material. The reformer is provided with a reforming chamber, the electromagnetic heater and a hydrogen purification device. The electromagnetic heater comprises the electromagnetic coil and a metal magnetized body. A high frequency magnetic field can be generated after the high-frequency voltage is input into the electromagnetic coil, so that the metal magnetized body emits heat due to magnetic field induction and provides thermal energy for the reforming chamber. The frequency converter is low in noise, good in cooling effect and low in energy consumption. According to the methanol water reforming hydrogen production machine, heat generated by the frequency converter can be utilized effectively.

The invention relates to a fluid control device, in particular to a novel electro-hydraulic servo valve. The novel electro-hydraulic servo valve comprises a shell (1), a valve element (7), a valve sleeve (2), a fixed throttling hole (5), a spraying nozzle (14), a coil (10), an armature (9), a spring pipe (12), a baffle (13), a feedback rod (19), permanent magnetic steel (8) and a pressure equalizing oil filter (11). The electro-hydraulic servo valve is characterized in that external pressure increased along with increase of submerged depth is used for equalizing pressure on the inner side and the outer side of the spring pipe (12) through the pressure equalizing oil filter (11), and the requirement for the structural strength of a cover body (6) and the spring pipe (12) is lowered. A changeable throttling device composed of the baffle (13) and the spraying nozzle (14) can increase the working stability of the electro-hydraulic servo valve and can also guarantee the driving capacity of the electro-hydraulic servo valve in deep-sea high-pressure high-viscosity fluid. The baffle (13) and the feedback rod (19) are integrally designed, and feedback moment is directly fed back to the baffle. The baffle (13) is a cylindrical baffle, and the machining difficulty of parts is lowered.

A high-power, tunable and narrow linewidth external cavity semiconductor laser belongs to the technical field of a semiconductor laser and aims to solve the problem that the comprehensive requirements such as mode characteristic, beam quality, linewidth, coherence and tunability of a single laser are difficult to be met. The high-power, tunable and narrow linewidth external cavity semiconductor laser is formed by directly coupling a gain chip, a tunable external cavity and an inclined power amplifier with a curved waveguide through an end surface, wherein the gain chip is used for achieving laser output of single-mode wide spectrum; the tunable external cavity adopts a silicon on insulator (SOI) material; the linewidth is narrowed by increasing cavity length and a quality factor Q of a laser resonant cavity; the tunability is achieved by the adoption of refractive index of a thermal modulation material; and by the arrangement of the inclined power amplifier with curved waveguide, laser output with high power and high beam quality is achieved under ensuring the stability of the gain chip and the tunable external cavity. By the high-power, tunable and narrow linewidth external cavity semiconductor laser, a novel semiconductor laser integrating a single mode, high power, high beam quality, narrow linewidth, high coherence, tunable wavelength and the like is achieved, and the high-power, tunable and narrow linewidth external cavity semiconductor laser has important application prospect in the fields such as space laser communication and laser radar.

The invention discloses a self-cleaning method for an air conditioner heat exchanger and an air conditioner. The air conditioner comprises a heat exchanger and an electric heating piece; and the electric heating piece corresponds to the heat exchanger. The self-cleaning method for the air conditioner heat exchanger comprises the following steps: acquiring a self-cleaning control command and entering a self-cleaning mode; adjusting the rotating speed of a fan of the air conditioner and / or reducing the temperature of an indoor heat exchanger to enable the heat exchanger to be frosted; after frosting is finished, starting the electric heating piece to defrost the heat exchanger; and detecting the temperature of an air duct on the periphery of the electric heating piece, and reducing the working power of the electric heating piece when the temperature of the air duct is greater than or equal to a preset safe temperature. By the technical scheme, the workings stability of the air conditioner in a defrosting process is improved, and the self-cleaning effect is greatly improved.

The invention belongs to the field of centrifugal pumps and particularly relates to a series-parallel connection centrifugal pump which has the flow channel series-parallel connection switching capacity. The series-parallel connection centrifugal pump comprises a pump body and a pump shaft. The pump shaft is provided with two impeller parts, and a first cavity channel and a second cavity channel are formed in a pump cavity corresponding to the two impeller parts. A first bypass flow channel, a second bypass flow channel, a first liquid outlet flow channel and a second liquid outlet flow channel are formed in the pump body, wherein the first bypass flow channel and the second bypass flow channel are used for communicating an outlet of an external liquid inlet pipeline and an inlet of the first cavity channel as well as the outlet of the external liquid inlet pipeline and an inlet of the second cavity channel respectively, and the first liquid outlet flow channel and the second liquid outlet flow channel are used for communicating an inlet of the external liquid outlet pipeline and an outlet of the first cavity channel as well as the inlet of the external liquid outlet pipeline and an outlet of the second cavity channel. A branch flow channel is further arranged in the pump cavity, one end of the branch flow channel is communicated with a liquid inlet of the second cavity channel, and the other end of the branch flow channel is communicated with the first liquid outlet flow channel to form a three-way joint. The series-parallel connection centrifugal pump further comprises a switching part, a switching assembly is arranged at the second liquid outlet flow channel, and the switching assembly and the switching part are in electric linkage or mechanical linkage. Due to the linkage structure, the series-parallel connection centrifugal pump is reasonable and practical in structure, long in service life and reliable and stable in work.

The invention discloses a damping unit, which comprises a first elastic element, a second elastic element and a guide sleeve, wherein the second elastic element is arranged under the first elastic element and is abutted against the first elastic element, the guide sleeve is inserted in inner holes of the first elastic element and the second elastic element, the length of the guide sleeve is smaller than the sum of the lengths of the inner holes of the first elastic element and the second elastic element in the axial direction of the guide sleeve, and an accommodating part is arranged between the first elastic element and the second elastic element and is used for clamping and accommodating an element to be damped. The damping unit has the advantages that reliable relative position relationship of the two elastic elements can be maintained in the pressing and resetting process; on the basis of ensuring the operation stability of the damping unit under the bearing state, the damping unit is suitable for the connecting brackets of engines different in models, so the adaptability is greatly improved. On the basis of the damping unit, the invention also provides a damping device using the damping unit and an engine test system using the damping device.

The invention discloses a self-cleaning method of an air conditioner heat exchanger and an air conditioner. The air conditioner comprises the heat exchanger and heating parts. The heating parts are arranged to correspond to the heat exchanger. The self-cleaning method of the air conditioner heat exchanger comprises the following steps that a self-cleaning control command is acquired and controlled, and a self-cleaning mode is executed; the rotating speed of a fan of the air conditioner is adjusted and / or the temperature of the indoor heat exchanger is reduced so as to enable the heat exchangerto be frosted; and when frosting is completed, the heating parts are started, and the opening degree of a throttle valve of the air conditioner is adjusted so as to defrost the heat exchanger. According to the technical scheme, the work stability of the air conditioner in the defrosting process is improved, and the self-cleaning effect is greatly improved.