617results about How to "Reduce heat loss" patented technology

The invention discloses a processing method for sintering alumina by a novel dry soap lime, which comprises the following steps: (1) raw materials, i.e., broken bauxite, limestone, sodium carbonate and coal are sent to a ball mill to be milled until the oversize product of 100<#> is not lager than 5 percent, and raw meal is made into raw meal balls of 30-50mm; (2) clinker sintering: the raw meal of the step (1) is calcined in a vertical kiln at the temperature of 1150-1250 DEG C to prepare the clinker; (3) clinker leaching: the clinker is leached by the lotion of Bayer process, and then the solution is sent to a desilication groove; (4) decomposition: the desiliconized solution is combined with a Bayer solution, and then the mixture is put into a leaf filter and enters a decomposer to be decomposed by adding seed crystal; and (5) roasting: aluminum hydroxide is roasted into alumina at 950-1200 DEG C. The processing method has the beneficial effect that the water content of the raw meal is reduced to 10-15 percent, thus greatly reducing the specific heat consumption in the sintering process by little change and acquiring higher economic benefits.

The invention discloses a manufacturing method of a GaInP/GaAs/InGaAsP/InGaAs four-junction solar battery. By utilizing a wafer bonding method, the GaInP/GaAs/InGaAsP/InGaAs four-junction solar battery is integrated by a GaInP/GaAs double-junction solar battery growing based on a GaAs substrate and a InGaAsP/InGaAs double-junction solar battery growing based on an InP substrate; by utilizing the InP as a supporting substrate, the four-junction solar battery with respective band gap energies of 1.9/1.4/1.05/0.72 eV is realized, sunlight full spectral absorption and energy conversion are realized to a greater degree, and 32.8 percent of efficiency is realized in irradiation of AM1.5G and under the sun. Based on the development of two kinds of double-junction batteries, the bonded four-junction solar battery reduces the shortages of high cost caused by utilizing a plurality of different substrates in a mechanical cascade solar battery system and complex optical system and optical loss in an optical integrated battery, and effectively solves the problem of lattice mismatching of growing a uniwafer four-junction cascade semiconductor solar battery material. The high voltage and low current outputs are realized and the resistance consumption in a high concentrator battery is reduced.

The invention relates to a continuous-casting and continuous-rolling integrating device and a continuous-casting and continuous-rolling integrating process. An ejection roller way in an ejection roller way ejection area and a transition roller way are linearly and continuously jointed and a moveable baffle plate which can automatically lift is arranged at the joint; the ejection roller way and a heat conveying roller way are jointed through a casting blank separating device with a heat-preserving device; a set of blank-separating collecting device which can move bi-directionally is jointly used between a cooling bed and the transition roller way as well as between the transition roller way and the heat conveying roller way and can drive casting blanks to bi-directionally move between the cooling bed and the transition roller way; a heater is arranged on the heat conveying roller way; the tail end of the heat conveying roller way is jointed with a rolling machine. According to heat conveying and rolling requirements, the casting blanks are selected, separated and collected, according to casting blank temperature data which is detected in real time, the heating temperature and the heating time are automatically adjusted, the casting blanks are heated to the temperature meeting the rolling requirement and are fed into the rolling machine to be rolled, the metal yield can be increased, the continuous-casting blank quality can be improved, the energy consumption can be reduced, the utilization efficiency, the maintenance rate and the production efficiency of equipment are improved, and the investment cost and the operation cost are reduced.

A bag-in-box beverage container and dispenser is provided, incorporating an outer shell fabricated preferably from corrugated paperboard material, and a plurality inner liquid containing bags, fabricated from a suitable plastic material. The carton includes ready assembly features, as well as at least one internal ramp structure for prompting flow of liquid toward a plurality of dispensing apertures disposed in the outer shell. A recessed handle structure is also provided, as are alternative embodiments of the internal ramp structure.

Systems and methods are described for sensing particulate matter in an exhaust system of a vehicle. An example system comprises a first outer tube with a plurality of intake apertures on an upstream surface, a second inner tube with a plurality of intake apertures on a downstream surface, and a particulate matter sensor placed within the second inner tube. The second inner tube may be positioned within the first outer tube such that a central axis of the second inner tube is parallel to a central axis of the first outer tube.

A reformer which enables rapid load changes of up to 100% within a few seconds and is intended to produce hydrogen from hydrocarbons by steam reformation, comprises an evaporator cooler for cooling the reformate and for generating steam. The evaporator cooler is disposed in the reformer, on the end of its reaction vessel. It keeps the applicable end of the tube cool and uses the waste heat of the reformate for generating steam. This makes fast load changes possible, because an increase in the introduction of water immediately causes an increase in the reformate produced and thus an increase in the heat output.

A solar heat collector containing heat accumulating material features that the heat accumulating material contained in a sealed metal container is arranged between the heat sucking plate and bottom plate of traditional flat-type air heat collector for sucking and accumulating the excessive solar heat.

The invention relates to a model for optimally controlling a heating system of a large walking beam type heating furnace plate blank, which belongs to the technical field of industrial heating. A billet steel heating system optimizing model is adopted to optimize the order of entering the furnace for the billet steel of different steel type; the billet steel heating time and the temperature of each segment of the heating furnace are optimized; and the temperature change of the billet steel in the heating process is predicted. The model consists of a temperature control module of a single steel type of billet steel, and a heating optimal control module of multiple steel types of billet steel, wherein one module aims at simulating the heating process of a signal block of billet steel, and the other module aims at simulating the heating process under the condition of 10 blocks of billet steel entering the furnace, i.e. mixed loading furnace entering condition. The model is adopted to optimize the heating system of the billet steel so as to avoid the overhigh heating temperature of the billet steel and reduce the oxidation burning loss of the billet steel; reasonable heating time can be adopted to reduce unnecessary fuel waste and fuel consumption; and the model is conducive to scientifically and reasonably regulate the operation parameters of the heating furnace and meet the requirements on billet steel heating quality.

The invention provides a defrosting control method for an air conditioner. The air conditioner comprises a compressor, a first four-way valve, an indoor heat exchanger, a throttling device, an outdoor heat exchanger, a refrigerant pipeline, a second four-way valve, an electromagnetic valve and a heat storage device. When the air conditioner is in heating operation, the first four-way valve and the second four-way valve are both converted into a heating mode, a heat storage mode for the heat storage device is controlled to be started and stopped by controlling the on-off state of the electromagnetic valve, and heat stored by the heat storage device is used for achieving a heat source provided when heating and defrosting are simultaneously conducted. When the air conditioner is in defrosting operation, the first four-way valve is kept in the heating mode, the second four-way valve is converted into a refrigerating mode, the electromagnetic valve is opened, refrigerant gas sprayed by the compressor is divided into two branches, the refrigerant gas exhausted by the compressor simultaneously flows to the indoor heat exchanger and the outdoor heat exchanger, in the defrosting process, refrigerant simultaneously flows to the indoor heat exchanger and the outdoor heat exchanger, certain heat exists on the indoor side, cold radiation is not generated, and user comfort is greatly improved.

A vehicle system includes an engine that can operate as a compressor, as an air motor and an internal-combustion engine. It also includes short-term and long-term air-storage reservoirs filled with compressed air. During braking, the engine slows down the vehicle by pumping compressed air into the short-term storage. That air is later used for vehicle propulsion. The engine uses the recovered braking energy whenever possible, but when the compressed air in the short-term storage is exhausted; it switches to the long-term storage and continues to operate with compressed-air assist. The amount of compressed air in the long-term storage is such that it is sufficient for a typical day of driving. An on-board electrically-driven compressor, using an outside source of electric power, charges the long-term storage during overnight parking. In this way, electric power from an electric grid is indirectly used for vehicle propulsion. If the compressed air in both reservoirs is exhausted, the engine switches to internal-combustion.

The invention relates to a pressure-bearing type solar collector based on a groove-type parabolic mirror. The parabolic mirror is characterized by comprising an elliptical reflecting canister, a housing, a groove-type parabolic condenser and a pressure resistant metallic heat collection pipe group, wherein the reflecting canister adopts an elliptical stainless steel mirror reflecting canister or a glass reflecting canister; a light inlet is formed in the elliptical reflecting canister; the housing is arranged outside the reflecting canister; a gap between the housing and the reflecting canister is filled with heat insulating materials; the pressure resistant metallic heat collection pipe penetrates the reflecting canister; and the light condensation focus of the groove-type parabolic condenser is positioned at one focus near or around one side of the light entrance port. According to the solar collector provided by the invention, the heat absorbing medium is positioned in the pressure resistant metallic heat collection pipe groups in the black body cavity, so as to enable the whole heat-collector to manufacture the pressure-bear structure smoothly, the requirement of the process and material is decreased greatly, the manufacturing cost of the pressure-bearing type solar collector based on the groove-type parabolic mirror is decreased, the performance of the heat collector is more steady and reliable, and the safety coefficient is high.

The invention provides a photovoltaic array combiner box which comprises multiple DC (direct current) input branches, wherein the multiple DC input branches are connected in parallel and then combined into one DC output; and each branch has a maximum power tracking function so as to work at respective maximum power point. The combiner box also comprises multiple voltage compensation units connected in series with the branches respectively, and a comparison calculation unit, wherein the comparison calculation unit is used for comparing to obtain the maximum value of voltage at the maximum power point of each branch, calculating the difference between the maximum value and the voltage value at each maximum power point respectively, and outputting the difference to the voltage compensation unit corresponding to each branch respectively; and the voltage compensation unit is used for performing voltage compensation for the corresponding branch according to the difference so that the output voltage of the branch is equal to the maximum value. The photovoltaic array combiner box provided by the invention can ensure that each branch still can output voltage at respective maximum power after the output is combined, thus the total output power of the combiner box reaches the maximum.

The invention relates to an air conditioning controller special for curing tobacco and a control method thereof. The special air conditioning controller for curing tobacco comprises a wire controller; the wire controller comprises an input unit and an MCU of the wire controller, which are connected; the MCU of the wire controller is respectively connected with a first display unit, a cured tobacco curve, a tobacco-curing recording memory unit, a spare power supply unit, a dry-bulb temperature and wet-bulb temperature detection unit, a load control interface unit, a heat pump system protective unit and a three-phase power fault tolerant unit; and the MCU of the wire controller receives a control instruction from the input unit so as to control the working states of a heat pump and an electric heating and dehumidifying device. The air conditioning controller utilizes the heat pump heating technology and a heat recovery device in the process of curing tobacco, can reduce the air pollution and save energy, can also improve the curing quality of the tobacco and reduce the working intensity of curing tobacco, control the dry-bulb temperature and the wet-bulb temperature in a curing room precisely and greatly improve the automation degree and the control precision.

The invention discloses a micro-combustor, which comprises a bluff body, two preheating channels and a combustion chamber, wherein the preheating channels and the combustion chamber are all plate-shaped; the cross section of the bluff body is triangular or circular; the bluff body is arranged at an inlet of the combustion chamber; the ratio of the width of the bluff body to the width of the combustion chamber is 0.3-0.6; the two preheating channels are both L-shaped and are respectively arranged at upper and lower sides of the combustion chamber; and outlets of the preheating channels are both communicated with the inlet of the combustion chamber. By using the micro-combustor, the defect of the prior art is overcome. By preheating and catalyzing fuels and air (when a non-pre-mixing combustion mode is adopted) or the pre-mixture of the fuels and air (when a pre-mixing combustion mode is adopted), the energy used for igniting is lowered, the igniting delay time is shortened and the exhaust heat loss is reduced. Besides, a low-speed high-temperature recirculation region formed behind the bluff body is utilized to fully mix the fuels and air, prolong the gas retention time and stabilize the flame. The micro-combustor can be used for efficiently expanding the stable combustion limit and increasing the combustion efficiency and can be widely applied to various micro-power systems.

The invention provides a static chuck. The static chuck comprises a chuck used for carrying a processed workpiece and a pedestal. A heat insulation component is arranged between the chuck and the pedestal. The heat insulation component comprises an upper ring plate, a lower ring plate and an expansion heat insulation ring. The upper ring plate and the lower ring plate are closed annular structure components and are arranged oppositely. The expansion heat insulation ring is a closed annular thin wall structure component and is arranged between the upper ring plate and the lower ring plate. Two end portions of the expansion heat insulation ring form sealed fixing with the upper ring plate and the lower ring plate respectively. The static chuck possesses a good heat insulation effect and can heat uniformly so that heating efficiency and heating uniformity of a plasma processing equipment are increased. Besides, the static chuck is convenient to be processed and replaced so that usage cost of the static chuck is reduced.

The invention discloses a three-phase multi-material three-dimensional pressurized clash coal gasification device and a process thereof, which comprises a coal slurry preparing and conveying mechanism, a dry coal powder preparing and conveying mechanism and a pressurized gasification mechanism, wherein the coal slurry preparing and conveying mechanism consists of a coal mill, a coal slurry groove, a high-pressure coal slurry pump and a high-pressure coal slurry pipeline; the dry coal powder preparing and conveying mechanism consists of a dry powder preparer, a dry powder storage groove, a screw-rod conveyer, a coal powder pipeline and a nozzle feeding bin; and the pressurized gasification mechanism comprises a combustion chamber and a quench chamber. A water-coal slurry nozzle and a dry coal powder nozzle are arranged on the combustion chamber and are respectively communicated with the interior of the combustion chamber; and the dry coal powder nozzle and the water-coal slurry nozzle are also connected with a high-pressure gas pipeline. The dry coal powder nozzle arranged at the top reduces the damages of the returned air current mixture to the vault and the blind-head firebricks, thereby improving the utilization rate of the equipment. The injection mode of the dry powder and the carbon dioxide at the top increases the content of carbon in the reactants, and the active ingredients in the coal gas are increased to 85% above, thereby improving the utilization ratio of the coal resource and reducing the discharge amount of carbon dioxide.

There is an accurate pressure-controlling electric rice cooker, which contains an inner pot inside pot body crust, and the inner pot is connected with electric plate, and there is a resilient seal ring between the inner pot and pot cover. Between the crust and the inner pot there is a middle pot; between the crust and the middle pot there is a heat-insulating layer. The electric rice cooker has a pressure switch, which contains an air duct or air channel connected with inner pot chamber. The other end of the air duct or air channel is communicated with a pressure membrane case, in which there are movable membranes that are joined with push rod. On the other side of the push rod there is a movable contact spring, which connects with an unmovable contact spring, and both the two contact springs couple with main controlling electric of electric rice cooker separately. This invention has simple and reasonable structure, its pressure controlling is accurate, safety degree is high, and after cooking it can exhaust quickly and safely, discharge pressure in blocked style, and its heat insulation effect is good, heat conductivity is high and is energy saving.

The invention relates to a grid connecting system of a permanent magnet synchronous wind driven generator. The grid connecting system of the permanent magnet synchronous wind driven generator comprises a wind machine, a permanent magnet synchronous generator, a generator side converter, a direct current booster module, a power grid side converter, an energy storage module and a control module. The wind machine, the permanent magnet synchronous generator, the generator side converter, the direct current booster module and the power grid side converter are connected in sequence, a first capacitor is connected between the generator side converter and the direct current booster module in parallel, a second capacitor is connected between the direct current booster module and the power grid side converter in parallel, the energy storage module is connected between the second capacitor and the power grid side converter in parallel, and the control module is respectively connected with the generator side converter, the direct current booster module, the power grid side converter and the energy storage module. Compared with the prior art, the grid connecting system of the permanent magnet synchronous wind driven generator adopts a high-frequency transformer to replace an original industrial frequency transformer to achieve high voltage grid connection, and adopts super-capacitors to store energy to enable the system to have good low-voltage operation performance.

The invention provides a method and a device for smelting iron in an arc furnace. The arc furnace part comprises a furnace body, a furnace cover, an electrode, feeding equipment and discharging equipment. The device comprises at least one pair of heating furnaces and at least one pair of heat accumulators, wherein the heating furnaces are connected with the furnace body of the arc furnace through a connector; one end of each of the heat accumulator is connected with the heating furnaces, while the other end is connected with a discharge system, a fan and a gas processing device respectively. In the invention, product gases generated in a smelting and reducing process are fully utilized to combust to heat the heat accumulating bodies in the heat accumulators and the heat is introduced into the furnace body from the heat accumulators through gas cycles, so the heat use is maximized. The device flow is rational and the operation is flexible. The device and the method are applicable to the iron making production by smelting and reducing and also applicable to the smelting process of other metals or other reducing processes of metal oxides by carbon.

The invention relates to a device for in-situ environment remediation in an organic pollution site. The device comprises a water supply system, a water heating system, a flow valve, a superheated steam in-situ injection system, a monitoring well, a soil gas stripping and ground waste gas and wastewater processing system and the like. Water from the water supply system is fast heated by using the high-frequency water heating system and then enters the high-frequency superheated steam in-situ injection system through control of the flow valve, so that the superheated steam in-situ injection is realized; and meanwhile, the remediation effect is enhanced by using the soil gas stripping and ground waste gas and wastewater processing system, and a remediation effect is observed by the monitoring well. The device has the advantages that the problems that the heating speed is low, the steam injection temperature s low and the like of the traditional heating system are solved, organic pollutants which are high in boiling point and difficult to volatilize are efficiently removed, and meanwhile, energy can be saved by 50 percent.

An internal combustion engine and method is disclosed wherein separate compression and power cylinders are used and a regenerator or pair of regenerators is mounted between them to provide heat for hot-air ignition. The single regenerator embodiment operates as a two-stroke cycle engine and the embodiment with an alternating pair of regenerators operates as a four-stroke cycle engine. The engine varies the amount of air entering the power cylinder to control the engine output during naturally aspirated operation using valve timing and/or volume control of dead space and can optionally include supercharging to control the engine at higher output levels.

The invention relates to the production field of mineral wool, and particularly relates to a method and an apparatus for directly producing mineral wool from thermal state blast furnace slag. According to the apparatus for directly producing the mineral wool from the thermal state blast furnace slag, a slag ladle is disposed on a slag ladle vehicle; a stirring gas inlet is disposed at the bottom of the slag ladle; a slag ladle cover is provided with a material-feeding port, an exhaust port and a heating electrode; a tilting mechanism has a tempering station matched to the slag ladle and a homogenizing station matched to a homogenizing furnace; and the homogenizing furnace is communicated with a centrifugal wool-making machine through a melt flowing port. The process method for directly producing the mineral wool from the thermal state blast furnace slag comprises the steps of preparing the melt slag, tempering, homogenizing and making the wool. Mixed melt slag in the slag ladle is in no need of being transported to the homogenizing furnace, so that heat loss during the transportation process of the melt slag of the furnace is reduced; the homogenizing furnace makes the chemical components of the melt body more stable and uniform, so that the quality of the mineral wool fibers can be increased; and the process makes use of the heat energy of the melt slag, reduces cost for manufacturing mineral wool, and improves manufacturing environment of the mineral wool products.

The invention relates to a balance control system combining electricity compensation with resistance dissipation in an energy storage system. The balance control system comprises battery packs, an electricity compensation balance control portion and a dissipation balance control portion. The balance scheme and the control mode include that each unit battery corresponds to an electricity compensation balance circuit, and the electricity compensation balance is started when the voltage of each unit battery is low; and simultaneously, each unit battery is connected in parallel with a dissipation resistor, and when the voltage of the individual battery is high during charging, dissipation control switches are started to enable the batteries to discharge through serial connected resistors, so that the battery packs and a compensation power supply are protected. Compared with a pure resistor dissipative balance scheme, the balance control system has the advantages that only the balance resistors of the individual batteries with high voltages work, so that the heat can be ignored, and heat management loads can be added. Energy of the compensation power supply is fully used, thermal losses are small, the energy conversion efficiency of a management system is improved greatly, a plurality of batteries can be balanced simultaneously, the balancing speed is increased, and the balancing time is shortened.

A thermal treatment apparatus provided on a substrate includes a heat generating section the section includes a heat generating layer, a diffusion preventing layer which contacts one surface of the heat generating layer to prevent heat diffusion due to heat generation of the heat generating layer, and a cohering layer disposed between the substrate and the diffusion preventing layer.

The invention discloses an asphalt pavement in-place hot recycling heating device. The asphalt pavement in-place hot recycling heating device comprises a traveling mechanism and a heating system used for heating an asphalt pavement, wherein the heating system comprises a hot air generator used for generating hot air and a heating chamber used for guiding the hot air to the asphalt pavement and then heating the asphalt pavement, the lower end of the heating chamber is open, the open end is buckled on the asphalt pavement to be closed, and the heating chamber and the hot air generator are communicated with each other through an air intake channel and an air return channel in a circulating manner. The asphalt pavement in-place hot recycling heating device provided by the invention can be used for recycling low-temperature hot air after heat energy transfer with the pavement, and compared with the prior art, the asphalt pavement in-place hot recycling heating device can improve the utilization ratio of heat energy, reduce the heat energy loss and environmental pollution, save energy, reduce the construction cost, and realize sufficient and effective heat energy transfer between the hot air and the asphalt pavement so as to improve the heating depth and temperature, reduce the fuel consumption, save the energy and reduce the construction cost under the condition of reaching the required heating depth and temperature.

An apparatus for reducing the heat losses caused by the DC Bus capacitor current is proposed. The apparatus includes: a double frequency boost converter circuit having two boost converter circuits coupled in parallel, in which two switches, respectively disposed on the two boost converter circuits, are turned on and off alternately to produce an output current having a frequency twice that of control signals of the two switches, and to offer a DC bus respectively, a full-bridge DC-DC converter coupled to an output terminal of the double frequency boost converter circuit for transforming an output of the DC bus to a DC voltage, and a DC bus capacitor coupled to the double frequency boost converter circuit and the full-bridge DC-DC converter in parallel for balancing two corresponding transient powers of the double frequency boost converter circuit and the full-bridge DC-DC converter respectively.

A cathode holder of a tubular shape is inserted into an opening for a cathode of a plasma generating chamber with a tip of the cathode holder positioned outward from an inner wall surface of the plasma generating chamber. The cathode is held in the cathode holder so that a front surface of the cathode will be positioned outward from the inner wall surface. In the cathode holder is provided a tubular first heat shield surrounding the cathode with a space provided between the first heat shield and the cathode, the tip of the first heat shield positioned outward from the inner wall surface. At a rear side of the cathode is provided a filament. The gap between the cathode holder and the plasma generating chamber is filled with an electrical insulating material.

An electric cooking assembly includes a main body portion that defines a cooking area. First and second cooking surfaces are contained within the cooking area. A first electric heating element arranged to provide heat to at least a portion of the first cooking surface, and a second electric heating element is arranged to heat at least a portion of the second cooking surface. The main body portion may include first and second hood members. The first hood member defines the cooking area and the second hood member is positioned at least partially within the cooking area and configured to decrease heat lost from the cooking assembly during preparation of food products in the cooking area. The second hood member is configured for adjustment between an open position providing access to the cooking surface and a closed position covering at least a portion of the cooking surface.

The invention provides a device for alternately decomposing water to make hydrogen by oxygen permeating membranes and hydrogen permeating membranes. The device comprises a flat box body and inner pipelines, wherein the internal part of the flat box body is divided into a plurality of oxygen permeating chambers and hydrogen permeating chambers which are arranged at intervals; the inner pipelines extend inside all the oxygen permeating chamber and hydrogen permeating chamber; the inner pipelines of the adjacent chambers are connected with each other end to end through an outer pipeline; the inner pipelines and the outer pipeline form communicated serpentine steam channel; the inner pipelines in the oxygen permeating chambers are made of the oxygen permeating membranes; the inner pipelines in the hydrogen permeating chambers are made of the hydrogen permeating membranes; chemical potential difference exists between the inner and outer sides of the hydrogen permeating membranes of the inner pipelines in the hydrogen permeating chambers and chemical potential difference also exists between the inner and outer sides of the oxygen permeating membranes of the inner pipelines in the oxygen permeating chambers; and oxygen and hydrogen respectively enter the regions between the inner pipelines and the inner walls of the corresponding chambers through the oxygen permeating membranes and the hydrogen permeating membranes under the action of the chemical potential differences. According to the device, the steam channel is formed by alternate connection of the inner pipelines of the oxygen permeating membranes and the hydrogen permeating membranes, and the water vapor decomposition rate is much higher than that the situation of use of only oxygen permeating membranes or hydrogen permeating membranes.

The invention provides a coaxial water load for a medium-and-large-power calorimeter. The coaxial water load comprises a joint, a matching transformer, a thermal insulated transmission line, and a load structure. The joint is connected with the load structure through the thermal insulated transmission line and the matching transformer. Such structure extends the power measurement frequency range and improves the power measurement accuracy. With the design idea of the present invention, the power of kilowatts within 4 GHz can be accurately measured. The coaxial water load uses an N-type joint.To increase power capacity and a heat dissipation effect, the actual size of the water load is much larger than the diameter of the N-type coaxial line internal conductor. To reduce the reflection coefficient of the load and to improve the accuracy of the power measurement, the water load is required to have a low reflection coefficient, no high-order mode operation at high frequencies, high repeatability after repeated screwing operations, and high mechanical strength.