114 results about "Heat transfer problem" patented technology

To rapidly induce hypothermia to a patient, in the event the patient has a stroke, hyperthermia or some other temperature related heath problems which requires prompt action to regulate the temperature of the patient, a flat flexible structure conformable to the body of the patient is placed into contact with the patient. The structure has at least two heat transfer portions. One of heat transfer portions is positioned in contact with the body of the patient. The structure is hermetically sealed and a fluidized medium responsive to temperature change is provided in the structure between the heat transfer portions. The fluid is changeable between a liquid state and a gaseous state, when it is exposed to heat and cold. The heat absorbed by the heat transfer portion in contact with the patient is carried by the fluidized medium, as latent heat in the gas that results when the liquid is vaporized to its gaseous state, to the heat transfer portion layer not in contact with the patient, so that the latent heat in the gaseous vapor is dissipated. Upon dissipation, the gaseous vapor is condensed and the fluidized medium returns to its liquid state. The structure may be formed from a flat flexible heat pipe and may also be configured as a rib cage shaped jacket to embrace the torso of the patient. A cooling circuit or mechanism may be added to the structure to facilitate the removal of heat therefrom. The structure may also be used to raise the core temperature of a patient.

The invention relates to a method for producing alkoxylate through a microchannel reactor, and discloses a method for continuously performing alkoxylation reaction in a microreactor. According to the invention, initiator potassium alcoholate in which low molecules (the low molecules herein are mainly water and methanol) are removed and epoxide enter a microreactor, a delay line and a mixer in a liquid-phase form to perform liquid-liquid reaction, the purpose of sufficient mass transfer and heat transfer is achieved, and the liquid-liquid reaction is realized by increasing the pressure of the reaction system and adding a counterbalance valve. Compared with the alkoxylation reaction in the prior art, the method can effectively solve the heat transfer problem of such reaction, realizes fast and uniform mixing and constant reaction temperature, avoids the temperature runaway phenomenon and reduces the side reaction; the process is continuous flow reaction, and the reaction time is shortened to a few minutes, thus obviously improving the reaction efficiency and production efficiency; and the microreactor hardly has scale-up effect and is high in safety performance, thus being suitable for industrial production.

The invention discloses an efficient mixing heat exchange micro-channel reactor. The efficient mixing heat exchange micro-channel reactor comprises a dispersive mixing component, multiple reaction liquid passageway matrixes and heat exchange medium passageway matrixes. The reaction liquid passageway matrixes and the heat exchange medium passageway matrixes are arranged alternately. The dispersive mixing component is provided with dispersive mixing channels allowing two or more kinds of reaction liquid to dispersively flow in and be mixed to form mixed reaction liquid. The reaction liquid passageway matrixes are provided with reaction liquid passageways and heat exchange medium via holes. The heat exchange medium passageway matrixes are provided with reaction liquid via holes, heat exchange medium passageways, inflow holes and outflow holes, wherein the inflow holes and the outflow holes are communicated with the heat exchange medium passageways. The reaction liquid passageways of every two adjacent reaction liquid passageway matrixes are of a cascaded structure. The heat exchange medium passageways of every two adjacent heat exchange medium passageway matrixes are of a parallel structure. According to the efficient mixing heat exchange micro-channel reactor, the heat transfer problem is completely solved; mass transfer and heat transfer are enhanced, input of heat and cold is reduced, use of a solvent is reduced, the reaction yield is increased, energy is saved, consumption is reduced, and the efficient mixing heat exchange micro-channel reactor is environmentally friendly.

The invention discloses a simulation calculation model for the heat exchange performance of a straight tube type once-through steam generator and an algorithm thereof. According to the simulation calculation model, a one-dimensional homogeneous flow mathematic model of the once-through steam generator based on heat transfer partition is established, a secondary side heat exchange process is divided by adopting appropriate distinguishing conditions, a once-through steam generator heat exchange simulation program based on MATLAB (matrix laboratory) software is developed independently on the basis of the simulation calculation model, and the simulation for the steady state heat exchange performance of the once-through steam generator under different working conditions is carried out. The programming difficulty is simplified and reduced, automatic judgment and piecewise calculation can be realized, the range and position of wall temperature uprise and the lengths of heat exchange tubes in all heat transfer areas under different working conditions are accurately predicted, and thus a serious working area of the once-through steam generator is obtained. Theoretical support can be provided for preventing the accidents, such as overtemperature tube burst, of the once-through steam generator.

A thermal recovery method employing an electrical pre-heating method to condition the hydrocarbon-bearing formation as a means of improving recovery when steam injection is later applied. In addition, a method of comparing the applied electrical flux and resulting temperature profile to determine the heat transfer properties of each of a plurality of reservoir regions along the length of a horizontal well is disclosed. Advantageously, the heat flux supplied to each of the regions may be varied relative to each other region to compensate for different thermal transfer properties which may exist in the formation within each of the regions. Such controlled variation in thermal energy transfer, compensating for variances in fluid mobility and thermal properties in the reservoir allows for a more even steam chamber development and therefore optimized oil recovery.

The invention discloses a method for preparing an Invokana medicine intermediate by using a micro-reactor, which is characterized in that a compound III dissolved in an organic solvent and an organometallic reagent respectively passes through a material channel and are mixed in a micro-reactor unit (L), and passes through (L) and flow to the micro-reactor unit (H); a compound II dissolved in the organic solvent passes through the material channel and then is mixed with the above mixed liquor in the micro-reactor unit (H) at preset temperature, then a mixture passes through the micro-reactor unit (H), flow out from an outlet after a reaction is completed, a reaction solution is subjected to post treatment to obtain the target compound-Invokana medicine intermediate I. According to the invention, the Invokana medicine intermediate (I) is synthesized by the micro-reactor, so that heat transfer problem of the reactions can be effectively solved, the reaction objects in the micro-reactor can be fully mixed, reaction time is shortened, reaction efficiency is increased, almost no amplification effect is generated on the micro-reactor, the method has high safety performance, and is suitable for industrial production.

The invention provides a numerical simulation method for solid / liquid phase change in a high-temperature heat storage container in a gravity condition. Numerical calculation is carried out for the complicated problem of phase change heat transfer while natural convection, cavitation and radiation conditions are simultaneously considered, technicians can acquire change of melting rate of solid / liquid phase change materials in the high-temperature heat storage container in a field and distribution of a flow field, a temperature field and liquid phase by the aid of a computer, and accordingly important references for optimizing the design of heat storage containers, suppressing cavitation, improving heat storage efficiency and reducing 'hot spots' and 'hot release'. By the aid of the numerical simulation method, the complicated problem of melting / solidification inside the high-temperature heat storage container in the gravity condition is simply and efficiently solved by the aid of a calculation program based on an enthalpy method, a finite control volume method and SIMPLE algorithm, and the numerical simulation method has important practical values.

A heat conduction path topological optimization based underwater glider cruise path planning method is characterized in that: firstly, a path planning problem is converted into a heat conduction problem, a heat conduction finite element model is established and modeled after the shape of a planning space, an starting point is a heat source, and an end point is a heat outlet; and then heat conduction pipes are arranged with the minimum heat dissipation weak degree as an evaluating standard, the heat source communicates with the heat outlet, at this time, the obtained heat conduction arrangement line is a path of an underwater glider. The method can effectively avoid the situation that the a path planning result falls into a locally optimal solution, can be applied to path planning in a continuous space with a wavy terrain and intricate ocean currents, and can be applied to path planning of unmanned aerial vehicles and all-terrain vehicles; and through the growth type topology optimization method, the method improves the speed and the quality of path planning; finite element grids are processed through a heat rigidity equivalent method, two ends of the heat conduction pies do not need to be fixed on nodes established by a man like the conventional topology optimization method, and the obtained result is close to the optimal solution.

The invention discloses a direct fluid-solid coupling heat transfer analysis method for an engine cooling water jacket. The method comprises the following steps: 1, establishing a solid domain and a fluid domain parametric geometric model; 2, carrying out grid partition and grid quality inspection; 3, defining material attributes; 4, defining boundary conditions; 5, defining a coupling heat transfer interface; 6, setting solver parameters; 7, carrying out direct fluid-solid coupling heat transfer analysis considering boiling heat transfer and obtaining calculation results. The method can compensate for the inability to effectively evaluate the heat transfer process and the coolant flow condition between the solid region and the fluid region in a conventional engine cooling water jacket design process, and the method avoids the risk of cracking failure caused by the high temperature of the bridge area of the cylinder head fire surface.

A method, system and apparatus for analyzing heat flux bifurcation within a porous medium by analyzing a convective heat transfer process within a channel partially filled with a porous medium under local thermal non-equilibrium conditions. Either the thermal dispersion effect or the inertial effect can be considered in a physical model. Exact solutions can be derived for both fluid and solid temperature distributions for three interface thermal models at a porous-fluid interface. The required conditions for validity of each interface thermal model can be obtained, and equivalence correlations between different interface thermal models can be developed. The range of validity of local thermal equilibrium condition can be established, and heat flux bifurcation within a porous medium can be established and demonstrated. Furthermore, a Nusselt number can be obtained and investigated for pertinent parameters.

The invention discloses a method for forecasting the temperature of a slab of a hot rolling heating furnace, comprising the following steps of: firstly, carrying out simplified hypothesis on heat transfer of radiation; secondly, drawing a grid division diagram on a one-dimensional unsteady heat transfer problem, dividing a billet into 8 layers i.e. 9 nodes, and obtaining explicit difference equations with 9 nodes by utilizing a one-dimensional unsteady difference equation; and thirdly, determining an unknown thermal property coefficient f by adopting a genetic algorithm, and forecasting a temperature value of a next time by the explicit difference equations based on a temperature value of each node of a last time after determining the unknown thermal property coefficient f. By adopting the invention, the billet tapping temperature in a heating furnace can be accurately forecasted, and the tediousness and the complexity of calculation can be simplified.

The invention discloses a stable heat-collection control method for a light field of a trough type light-focusing solar thermal power plant, and solves the problem of poor stable heat-collection control effect of an existing light field. The stable heat-collection control method for the light field of the trough type light-focusing solar thermal power plant is characterized by comprising the following steps: (1) a condenser main loop of the light field of the trough type light-focusing solar thermal power plant is evenly divided into at least two temperature detection areas, each temperature detection area corresponds to a condenser unit and a branch loop of the condenser unit, a reference temperature value of each temperature detection area is set, and the temperature detection area feeds back detected actual temperature of heat transfer oil to a condenser local controller; (2) the condenser local controllers compare the actual temperatures of the heat transfer oil, which are fed back by the temperature detection areas, with the reference temperature values of the temperature detection areas, and then at least one of the following operations is carried out: (A) the rotating speed of a heat transfer oil pump is adjusted; (B) the working attitude of the condenser is converted; and (C) the flows of the branch loops of the condensers are adjusted.

The invention relates to a test device and a test method for limit heat-flow density of a porous material for a heat pipe. The test device comprises a heat insulation material, a stainless steel barrel, a test block, a condensation pipe, a heat transfer block, a heater and thermocouples. The method comprises the following steps of: increasing the power of the heater so as to gradually increase the heat quantity of the porous material and intensify the boiling of the porous material till the occurrence of a heat transfer limit, and calculating the limit heat-flow density of the material through data recorded by each thermocouple. The device and the method have the advantages that: the heat resistance and the heat transfer capability of different capillary structures during boiling can be compared by the device and the method, the test results are stable and reliable, and the device and the method can provide help for the design of the capillary structures of heat pipes.

The invention relates to a solid-state heat storage and heating characteristic matching design method based on heat transfer rate balance, which comprises the following steps of 1) obtaining structural data, material data and operating condition parameters of a high-temperature solid-state heat storage device; 2) establishing a heat transfer rate balance model between that high-temperature heat storage material and the electric resistance heating element; 3) establishing a heat transfer model between the high-temperature heat storage material and the electric resistance heating element according to the heat transfer rate balance model; 5) determining a heat transfer couple boundary condition between the air and the surface of the electric resistance heating element; 6) judging whether thesurface temperature of the electric resistance wire is in an operating temperature range. 7) obtaining the air inlet velocity parameter satisfying the design structure of the air duct of the regenerator and the operation temperature range, so that the structure and the performance of the electric heat element and the heat storage device are matched, thereby realizing the optimization of the wholestructure. (1) The rate of change of temperature is constant, according to which the heat transfer equilibrium equation can be calculated. (2) The heat storage material and the resistance wire match.(3) The shortening of the life of the electric heating element caused by the high temperature brittleness is avoided.

In various embodiments, phase change and heat exchange methods between heat collection, heat transfer, heat exchange, heat storage, and heat utility systems are described. In certain embodiments, the heat transfer fluids / heat exchange fluids, heat storage media, and working media in the system are all phase change materials with transition temperatures close to each other and in decreasing order and perform their respective function through phase changes within a relatively narrow temperature range. Methods to control heat transfer rate, heat exchange and / or heat charging / discharging rate between heat collection, thermal energy storage and heat utility apparatus at will are provided. Methods of controlling such systems are also provided.

The invention discloses a numerical simulation method for a plate impact jet flow heat transfer problem. The method comprises the following steps that: S1: establishing a calculation model, and according to experimental data, establishing a plate impact jet model which contains a thermal insulation impact face and a sealed plate; S2: carrying out grid division and grid independence verification onthe model; S3: setting a turbulence model, and selecting an SSTk-[Omega] model to be coupled with an intermittent transition model, a cross flow transition model and a Kato-Launder model; S4: according to a practical situation, setting a boundary condition and an initial value; S5: setting the solving way of ANSYS-FLUENT software; and S6: operating the ANSYS-FLUENT, obtaining the heat transfer distribution rule of the plate impact jet flow under different heights, and expressing the heat transfer rule by a dimensionless Nusselt number Nu. By use of the method, the influence of transition on the impact jet flow heat transfer is considered so as to better conform to the physical phenomenon of the impact jet flow heat transfer, and therefore, calculation accuracy is improved.

The invention discloses a sandwich type multi-layer composite material thermal performance numerical analysis method. The method is characterized by comprising the following steps: analyzing the actual physical process of a multi-layer heat transfer problem, and performing analysis and reasonable assumption by multiple models; giving a mathematical description and control equation for describing the heat transfer process of the multilayer material; proposing an interface boundary condition for describing a physical quantity discontinuity condition on the interlayer according to the characteristics of parameters, thickness, heat conduction coefficient and the like of the interlayer material; discretizing the multi-layer thermal insulation material heat conduction model by adopting a mathematical method to obtain a discrete linear equation set; solving the discrete linear equation set, and analyzing a result. The method can be used for carrying out high-precision rapid analysis on the heat conduction process and the thermal resistance performance of multi-layer composite materials such as sandwich steel and heat-resistant firewalls.

The invention discloses a new model reduction solution method for building envelope dynamic heat transfer. Aiming at building dynamic heat transfer problem, based on heat balance principle, a controlequation for building envelope dynamic heat transfer is established. According to the indoor and outdoor meteorological parameters and the thermal performance parameters of the envelope, the characteristics of the partial differential equation are analyzed, and the boundary conditions and initial conditions are established. By using the robust discretization method, the discretized state space form of the original system of the partial differential equation is obtained. Based on Laguerre orthogonal polynomials, a new model reduction method is proposed for the original system. Finally, the solution of the reduced order system is restored to the solution of the original system. Compared with the Krylov subspace model reduction method, the new method is more intuitive and simpler in time domain. Compared with the balanced truncation model, the computational resource consumption is reduced. The eigenorthogonal decomposition (POD) model reduction method is avoided to obtain the data set ofthe system state in advance.

The invention relates to a self circulation array pipe reaction device with an efficient mixer and a reaction method using the same. The material mixing problem is solved through the arrangement of anefficient mixer and a circulation pump. The heat transfer problem and the reaction flux problem can be effectively solved in time through installing an array pipe reactor and controlling the circulation quantity. The reaction device provided by the invention has the advantages that the heat transfer effect is good; the material mixing is uniform; the continuous and automatic reaction can be realized. The reaction method using the reaction device provided by the invention has the advantages that the operation is simple; the reaction efficiency is high; the heat transfer effect is good; side reactions are few; the reaction flux is great.

The invention relates to a device for regulating the thermoelectric generation power matched load in real time by changing heat transfer areas and belongs to the technical field of engines. The device comprises a tail gas inlet, a thermoelectric generation piece unit, a cooling liquid circulating body, a tail gas reutilization electromagnetic valve, a tail gas reutilization guide pipe, a tail gas outlet, a heat transfer piece mechanism, a tail gas outlet temperature sensor, a tail gas inlet temperature sensor and an electronic control unit. The lengths of heat transfer pieces in the heat transfer piece mechanism can be adjusted; and by adjusting the lengths of the heat transfer pieces and changing the heating areas of the heat transfer pieces, the heating temperature of the heat transfer pieces is changed, and accordingly power generated by a power generator is changed and made to be matched with the electricity load power. According to the device for regulating the thermoelectric generation power matched load in real time by changing the heat transfer areas, waste heat energy of an engine is fully utilized, and the utilization rate of fuel is increased; and the heat exchange areas of the heat transfer pieces are adjusted in real time according to the electricity load condition, the power of the power generator on the engine can be reduced, the loss of accessories of the engine is reduced, and accordingly the efficiency of the engine is further improved.

The invention provides an evaporation concentration device. In the invention, a plurality of heat transfer tubes with external diameter of 15mm-26mm are divided into a plurality of heat transfer tube groups in a closed evaporating pot, and the number of the tubes in the heat transfer tube groups sequentially is decreased or increased along the upward direction; heating steam sequentially flows from the heat transfer tube group with the maximum tube number to those with less tube numbers; and a supply dispersion quantity of solution in the heat transfer tube group per horizontal projection area is 10m<3> / h / m<2>-60m<3> / h / m<2>.

A calculation method for the heat transfer process of porous pyrolysis materials, including deriving the mass, momentum and energy conservation equations of each layer inside the composite material, realizing the solution of the mass, momentum and energy equations of the solid phase and gas phase inside the porous medium structure, and obtaining the solid phase temperature T, density ρ, thermal conductivity ks, gas phase density ρf, thermal conductivity kf, porosity φ, pyrolysis gas pressure p, decomposition gas overflow velocity un. The invention can analyze the heat transfer process of different kinds of carbonized pyrolysis materials, can display the pyrolysis process of the pyrolysis gas inside the material in three dimensions, obtain the pressure and velocity distribution of the pyrolysis gas, and the cloud map of the temperature distribution of the porous medium structure formed after pyrolysis . By calculating the heat transfer process of porous pyrolysis materials, it solves the problem that it is difficult to accurately calculate the temperature of composite materials and the ambient temperature in the cabin of hypersonic aircraft.

The invention discloses an unsteady wall heating flow distribution measurement method based on infrared thermography temperature measurement. The method is characterized by recording the time-varying temperature field of a heated wall by using infrared thermography; obtaining an unsteady heat balance equation because a selected object has a uniform wall thickness and is low in thermal resistance in the thickness direction and thus a wall heating problem can be simplified into two-dimensional unsteady heat transfer problem; then, taking the derivatives of the temperature field with respect to time and space, ignoring natural convection and heat radiation, and calculating a heating flow in two-dimensional distribution. The non-contact heat flow measuring method can measure the two-dimensional distribution of wall heat flow in real time.

An improved flow measurement device is provided in a flow path for direct measurement of flow. An internal heat source solves the problem of heat transfer in conventional mass flow meters. The heat transfer associated with the internal heater forms the basis of flow measurement, and improved accuracy is achieved. The flow measurement device advantageously eliminates the introduction of inaccuracies, bypass errors, or inaccurate assumptions that are inherent in a conventional bypass structure. The present measurement device eliminates the need for one or more bubblers and thus overcomes bubbler pressure sensitivity and the bubbler requirement for exact (and unstable) gas vapor saturation of conventional flow measurement. The flow measurement device works equally well with gases, liquids or mixtures of gases and liquids and provides greater control over flow rates with very high degree of precision.

The invention aims to provide a formula of a chemical heat storage material for heat transfer; the chemical heat storage material can achieve high-temperature, large-scale, low-cost and high-efficiency heat storage, and is suitable for heat storage and heat transfer at the temperature of 10-1500 DEG C. The chemical heat storage material is composed of three components at least comprising a group of chemical substances which can undergo a reversible reaction, a group of metal particles composed of metals or metal oxides, and a group of microporous particles composed of materials containing micropores, and the three components are mixed to form the chemical heat storage material. The metal particles are added in the chemical substances so as to achieve effective heat transfer, and the problem of heat transfer is solved; at the same time, the porous particles are added, so as to achieve a reaction among the chemical substances, achieve effective performing of the chemical reaction and make the reaction be an effective contact reaction; therefore, the chemical heat storage has actual industrial application values.

The invention provides an LED lamp with an optimized radiating fin dimension and structure according to the natural convection heat transfer basic experiment research results aiming at fin-type structures, which points out that the ratio of the height h of fins to the gap a between the fins is not more than 10.0, and the gap a is not less than 1.7mm. The heat dissipating capacity is further increased by additionally installing a convection shield (4), and thereby, the level that the aluminium consumption of heat dissipation per watt is less than 4g can be achieved. In order to realize standardization, a radiating fin is separated from an LED lampwick comprising an LED core (1) and a heat conduction core (12), wherein the radiating fin is a component fixed in a light fitting, and a specific scheme for solving the heat transfer problem between the heat conduction core (12) and the radiating fin is proposed.

The invention relates to the technical field of fluid heat transfer. The invention discloses a heat transfer pipe and a cracking furnace. The heat transfer pipe (1) comprises a tubular pipe body (10)provided with an inlet (100) allowing fluid to enter and an outlet (101) allowing the fluid to flow out, wherein a twisted sheet (11) is arranged on the inner surface of the pipe body (10), the twisted sheet (11) comprises a plurality of ribs (110) protruding towards the interior of the pipe body (10), and the ribs (110) spirally extend in the axial direction of the pipe body (10). The heat transfer pipe has a better heat transfer effect, and the thermal stress of the heat transfer pipe can be reduced, so that the service life of the heat transfer pipe is prolonged. Due to the fact that the heat transfer pipe is arranged in the radiation chamber of the cracking furnace, the heat transfer effect of the cracking furnace can be improved, the operation period of the cracking furnace is prolonged, and the high-temperature resistance of the cracking furnace is improved.

The invention provides a heat transfer pipe, and heat and mass transfer equipment having the heat transfer pipe. The heat transfer pipe comprises: two heat transfer pipe joints (11), which are respectively arranged on the two sides of the heat transfer pipe; and a twisted pipe body (12), which is arranged between the two heat transfer pipe joints (11) to connect the two heat transfer pipe joints (11) and has a twisted surface pipe structure. With the heat transfer pipe of the invention, the heat and mass transfer in an evaporation process can be strengthened, heat transfer coefficients of natural convection and forced convection inside and outside the pipe are at the same time improved, and manufacturing cost of an evaporator is reduced.

The invention provides a ratio of a chemical heat storage material for heat transfer. The ratio realizes high temperature, large scale, low cost and high efficiency heat storage and is suitable for heat storage and transfer at 10-1500 DEG C. The chemical heat storage material comprises three components such as at least one group of chemical substances capable of reversible reaction, a group of metal particles composed of metal or metal oxide, and a group of microporous particles composed of a microporous material. The above components are mixed into the chemical heat storage material. The metal particles realize heat transfer. The microporous particles realize a reaction of chemical substances so that the chemical reaction is effective and the reaction is an effective contact reaction andthus the chemical heat storage has the practical industrial application value.

The invention discloses a temperature-difference-drive-type self-adapting heat transfer pipe. A plurality of self-adapting heat transfer pipes with good heat conductivity are inserted vertically in a through mode in advance, and are used for receiving heat flow generated by heat source bodies, thus the density of the gas in the pipe is decreased because of expansion by heating, and the gas rises automatically so as to form the heat convection effect; the higher the temperature is, the greater the self circulation of heat convection is, and the effect is self-adaptive; after the measures that heat absorption is increased through blackening the surface, the temperature of gas passing through is lowered through manufacturing an expanded cavity structure, the heat transfer quantity is increased through coarsening disposal inside and outside, the rate of discharge is improved through painting a radiating layer on the inner layer of the pipe, the heat energy is converted into sound energy and the like are implemented, the heat transfer effect is intensified; the temperature-difference-drive-type self-adapting heat transfer pipe has the whole advantages of passive heat radiation, and has partial advantages of initiative heat radiation; especially the structure is simple, energy is not dissipated, and a converse heat accumulation function can also be realized; and the temperature-difference-drive-type self-adapting heat transfer pipe is suitable for heat transfer of a seal body and places which require heat source insulation and magnetic field interference interdiction.