236results about How to "Small heat transfer temperature difference" patented technology

A subsection compression-subsection heat supply-subsection gas expanding compression type machine set belongs to the technical field of heat pumps / refrigeration, and consists of a compressor, an expander, a heat exchanger, a second heat exchanger and a low-temperature heat exchanger. Gas working substances absorbing heat from the low-temperature heat exchanger and raising temperature enter the compressor; after the gas working substances are compressed in a low pressure compression section, a part of the gas working substances are provided for the heat exchanger to complete the heating of a heated medium at an initial stage; the part of the gas working substances enter the expander and is expanded at a low pressure expansion section; the other part of the gas working substances are provided for the second heat exchanger to complete the heating of a second stage of the heated medium after continuously passing through the whole compression process and raising temperature, and enter the expander from an inlet of the high pressure expansion section of the expander for expanding; the gas working substances completing the expanding work flow through the low-temperature heat exchanger to absorb the heat and raise the temperature and enter the compressor; and a heat regenerator is added to form a regenerative machine set. The gas expanding compression type machine set reduces temperature difference of heat transmission and improves the performance index; when taken as a heat pump, the gas expanding compression type machine set is particularly suitable for occasions with high heating temperature and wide range; and when used for refrigeration, the gas expanding compression type machine set can reduce power consumption.

This invention relates to a double- cycle high efficient heat pipe heat exchanging system that can control the heat exchanging quantity. There are evaporator and condenser two types of heat exchangers. The number of each type is one or several that formed by connected in parallel. This system includes: condensate supplying and distributing system; gas-liquid two phases flowing and separating system; gaseous phase transmitting and distributing system, liquid phase collecting and storing system; heat exchanging quantity controlling system. The evaporator of heat pipe, condenser, gas-liquid separator, liquid storage, solution circulating pump, liquid distributor, the connecting pipeline and related controlling parts are connected together to form the double cycles controllable heat pipe system. The solution pump, liquid distributor, evaporator and gas-liquid separator are connected together to form independent working fluid cycle, which settle the problems that working fluid carrying capacity is not enough and liquid distribution is uneven.

The invention provides a cooling system for the working face of the mine. The invention consists of a ground refrigerating unit, a cooling water recycling device, a cold wind preparing device and a cold wind conveying pipeline. The refrigerating unit and the cooling water recycling device comprise a compressor 7, a condenser 3, a throttle 8, a heat exchanger 10, a cooling water pond 1, and a fresh water pump 2. The cold wind preparing device is a wind spraying chamber 11, and uses the cold media water prepared by the refrigerating unit to spray the wind current, can comprises a wind-inlet grille 16, a wind outlet 20, a water squirting pipe 17, a nozzle 18, a breakwater 19, a wind chamber water falling pond 21, a general water inlet pipe 22, a general water outlet pipe 23 and the like. A plurality of rows of vertical water squirting pipes are arranged between the wind-inlet grille and the wind inlet, nozzles are arranged on the top of the water squirting pipes, and the general water inlet pipe introduces the cold media water of the refrigerating unit. The invention adopts the cold media water spray to process, and prepare the cold wind with the high wind volume, high temperature difference, high enthalpy difference; can reduce the times of the heat exchanging process, lower the heat transferring temperature difference, improve the whole efficiency, and reduce the cold volume waste of the middle course; thereby is applicable for cooling the high-temperature hot and harmful circumstance.

The invention discloses a combined cooling heating and power system for thermal energy gradient utilization and belongs to the technical field of energy. The combined cooling heating and power system for thermal energy gradient utilization comprises a steam Rankine cycle loop subsystem, an organic Rankine cycle loop subsystem and an absorption refrigeration circulation loop subsystem, wherein a first generator of a first expander of the steam Rankine cycle loop subsystem is driven to generate; dead steam or extraction steam in an outlet is divided into two paths, respectively working as a heat source for the organic Rankine cycle loop subsystem and the absorption refrigeration circulation loop subsystem; and energy gradient utilization can be achieved, so energy utilization rate can be improved. The steam Rankine cycle loop subsystem can provide power, the organic Rankine cycle loop subsystem can provide power electricity and daily use hot water and the absorption refrigeration circulation loop subsystem can provide cold water for air conditioners in summer and hot water for radiation type tail end air conditioners in winter. The system can achieve combined heat and power generation or combined cold and heat power generation via a valve according to user needs; and the combined cooling heating and power system for thermal energy gradient utilization is flexible, reliable, energy-saving and practical.

The invention discloses a control method for a combined refrigerating multi-split air conditioner system. The multi-split air conditioner system is characterized in that two or more outdoor combined refrigerating modules are arranged the outdoor side to form a cold source system of the multi-split air conditioner system, each outdoor combined refrigerating module is composed of a first refrigerant vapor compression and refrigeration circulating loop and a second refrigerant circulating loop, one or more direct evaporation type indoor air cooler modules are arranged at the indoor side, and a refrigerant storing and conveying unit is connected with the part between each outdoor combined refrigerating module and the corresponding indoor air cooler module to form a closed circulating system through a liquid collecting tube, a main liquid supply tube and a main air return tube. According to the control method for the combined refrigerating multi-split air conditioner system, the number of the indoor and outdoor modules is decided according to the designed thermal load of an air conditioner, and the control method precisely regulates the refrigerating capacity to meet the heat control needs of round-the-clock running data machine rooms and electronic equipment; the control method for the combined refrigerating multi-split air conditioner system is capable of making the maximum use of the natural cold source of the day and night, transition season and winter so as to realize the great energy conservation and emission reduction of the air conditioner system.

The invention provides a multiple effective reflux falling film evaporation system used for recycling organic solvent. The invention is mainly used for recycling the solvent in water solution of the organic solvent during the concentration production process of plant extractions in food industry and biopharmaceutical industry. The invention adopts falling film evaporators with high heat transmission coefficient and small terminal temperature difference to form the multiple effective evaporation system. Each evaporator is provided with a solution circulating pump which increases down-flow quantity in a heat transfer tube and avoids dry wall of a heat transfer surface and enhances heat transferring, thus having great evaporation ability and high efficiency. The condensate of each evaporator enters into a corresponding condensate tank respectively and is discharged by the pump and recycled. A gas-phase communicating pipe is arranged between the condensate tank and a gas-liquid separator, which guarantees the discharge of noncondensable gas under vacuum operation condition, thus being beneficial for improving condensing and heat transferring efficiency. The invention is a new technique, new technology and new device used in concentration process of the extractions of the organic solvent and used for recycling solvent, which has high recycling rate, little energy consumption and convenient operation and can use a vacuum low temperature evaporation concentration production device in continuous and intermittent production operation.

The invention discloses a dual-temperature-heat-pipe constant-temperature and constant-humidity air-conditioning unit, comprising an air treatment circulating system and a dual-temperature refrigeration circulating system which are coupled through a high-temperature evaporator (3) and a low-temperature evaporator (5), wherein the air treatment circulating system comprises an air inlet (1), a filter (2), the high-temperature evaporator (3), a heat pipe exchanger evaporation section (4), a low-temperature evaporator (5), an air blower (6), a heat pipe exchanger condensation section (7), an electric heater (8), an electrode-type steam humidifier (9) and an air supply outlet (10) which are arranged in sequence according to the air flowing path; and the dual-temperature refrigeration circulating system consists of a high-voltage level refrigeration circulating loop and a low-voltage level refrigeration circulating loop. The dual-temperature-heat-pipe constant-temperature and constant-humidity air-conditioning unit also comprises a temperature sensor (18), a temperature controller (20), a humidity sensor (19) and a humidity controller (21). The dual-temperature-heat-pipe constant-temperature and constant-humidity air-conditioning unit disclosed by the invention can be used for effectively solving the problem of the common cold-hot offset and has greater energy-saving potential.

The invention relates to fixed bed combined reaction equipment which mainly comprises a cylindrical shell with an end enclosure, a reaction gas inlet and a reaction gas outlet on the shell, a porous gas distributor, a porous gas collection plate, a catalyst layer and a heat exchange pipe for cooling media to transfer heat; steam headers provided with stream pressure adjusting valves form a cooling medium circular loop of which catalysts in at least one heat exchange reaction area are filled in the pipe. The fixed bed combined reaction equipment ensures that heat transfer is designed according to the requirement on the amount of the reaction heat transfer in the reaction, is used for the synthesis of methanol and dimethyl ether, methanation, F-T reaction, the preparation of phthalic anhydride by ortho-xylene oxidation and other strong-effect reaction processes, reduces the temperature difference, improves the reaction efficiency and the yield, saves energy, reduces consumption and achieves the large-sized aim.

The invention relates to an inner thermal storage solar low-temperature thermal power generation system. The power generation system comprises a compound parabolic heat collector system, a thermal storage system and an organic Rankine cycle power generation system, wherein, the compound parabolic heat collector system comprises a high-temperature end compound parabolic heat collector array and a low-temperature end compound parabolic heat collector array; the thermal storage system comprises a liquid storage tank, a coil and a phase-change material; and the coil is evenly distributed in the liquid storage tank and the coil is internally filled with the phase-change material. The organic Rankine cycle power generation system comprises an evaporator, a steam turbine, a motor, a heat regenerator, a condenser, two pumps and six valves. Compared with the traditional solar thermal power generation system, the inner thermal storage solar low-temperature thermal power generation system is characterized in that: an inlet end of the steam turbine is provided with a phase-change thermal storage system which usually has very small power of thermal storage and heat release, thus reducing the average heat-exchange temperature difference between the phase-change material and an organic working substance; and on the other hand, a two-stage evaporator of a two-phase region and a liquid region is adopted in the system, thus being capable of reducing heat transfer irreversibility between heat-transfer fluid and the organic working substance, and lowering the average operating temperature of the heat collectors.

The invention discloses a design method of a solar energy uniform light superposition reflective condenser, wherein a light receiving surface is a photocell plate or a circular heat collection pipe. The design method is characterized in that a condensing lens consists of a limited number of flat plate reflection mirrors and broken line-shaped reflection mirror slot frames and is placed on a solartracking frame, a precise calculation formula of the width and the position of a space coordinate of each reflection mirror and the detailed steps of the geometric mapping method are deduced accordingto the constraint condition that two parallel light rays reflected by two end points of a line segment of a cross section of each reflection mirror respectively fall on two end points of a line segment of the cross section of the photocell plate or are respectively tangent with the circumference of the cross section of the circular heat collection pipe and the normal line of a mirror surface of the reflection mirror is an angle bisector of an included angle between incident light and reflected light, thereby ensuring that the reflected light of each flat plate reflection mirror is uniformly superposed on the light receiving surface, leading the single-chip output features of the photocell to be consistent, improving the light-emitting efficiency of components, leading the processing of the condenser to be easy and reducing the cost. The calculation formula can be used for optimizing the tilt angle and the nominal focal length of the photocell plate.

This invention relates to a multi-stage serial large temperature-difference compression thermal pump set composed of multiple stages of condensers, evaporators, a compressor and a related throttle device and connection pipelines, in which the waterway systems of the condensers of each stage and evaporators are serial to form a connected in-out system of waterway, pipelines of cold-producing medium of the adjacent condensers are serial by the throttle device, the condenser of the last stage is connected with the evaporator of the first stage by the compressor to form a channel of cold-producing medium.

The invention relates to the technical field of heat exchanger, in particular to a flat pipe which comprises not less than two through holes which extend along the lengthwise direction of the flat pipe. The through holes are arranged side by side along the width direction of the flat pipe. Two ends of the flat pipe along the width direction respectively form an external air influx entrance end and an external air outflux end. The section sizes of the through holes are reduced gradually along the direction from the external air influx entrance end of the flat pipe to the external air outflux end of the flat pipe. The through hole near the external air influx entrance end of the flat pipe has larger section size, larger heat transmission temperature difference, large heat exchange volume and larger mass flow. The through hole near the external air outflux end of the flat pipe has smaller section size, lower heat transmission temperature difference, less heat exchange volume and less mass flow. The invention brings the heat exchange performance of the flat pipe into play completely and improves the heat exchange efficiency of the heat exchanger further. The invention also provides a heat exchanger.

The invention discloses a high-efficiency compact high-temperature absorption type heat pump unit, and belongs to the technical field of heat pump devices, which consists of a generator, a condenser, a high-pressure absorber, a high-pressure flash tank, a low-pressure absorber, a low-pressure evaporator, a solution heat exchanger, a throttling device, a solution pump, a coolant pump and various types of connecting pipeline accessories. By adopting a method of two-stage evaporation and two-stage absorption and directly heating coolant water, which is evaporated from the high-pressure flash tank under high pressure, by using heat generated in the low-pressure absorber, the absorption type heat pump unit can recover low-temperature remaining heat to generate high-temperature hot water, and has higher energy source utilization ratio and a more compact structure. The low-pressure evaporator absorbs heat from a low-temperature heat source, the coolant water evaporated under high pressure is heated by using the heat generated in the low-pressure absorber, and finally the hot water is heated by using the heat generated in the high-pressure absorber and the condenser so as to generate the hot water at the temperature of 90 DEG C or above. The heat transfer temperature difference between low-pressure absorption and high-pressure evaporation is reduced, and the unit process is simplified.

The invention provides a multistage compression and stepwise heat utilization steam compression heat pump, which belongs to the technical field of waste heat utilization and heat pump refrigeration. Aiming at the shortcomings of the single condensation to heat release unit in stage compression and inter-stage cooling, the heat pump provides the steam compression unit which comprises two or more compressors, two or more condensers, an evaporator and a throttle valve, and the steam compression unit can implement condensation and heat release to outside respectively by each compression and heat moving flow. A low temperature compression and heat release flow is composed of a low-pressure compressor and condenser, a throttle valve and a evaporator; a high-temperature compression and heat moving flow is composed of a high-pressure compressor and condenser, a throttle valve and other parts by virtue of the structure of the low-temperature compression and heat moving flow; the residual heat medium can release heat by flowing through the evaporator; the heat medium absorbs heat by flowing through the each compression and heat moving flow. The multistage compression and stepwise heat utilization steam compression heat pump has the advantages that: the heat transfer temperature difference is reduced; the unit performance index is improved; while being used as a heat pump, the heat pump is particularly suitable for the occasion with high heat supply temperature and wide range, and can be used for refrigeration and power consumption reduction.

The invention provides a heat pump system of heat humidity independent control driven by condensation waste heat and based on solid dehumidification. The heat pump system provided by the invention comprises a first fan, a second fan, a first dehumidification heat exchanger, a second dehumidification heat exchanger, a first air regulating valve, a second air regulating valve, a compressor, an expansion valve, a bidirectional four-way valve, a first air duct, a second air duct and a refrigerant circulation pipeline, wherein the surfaces of the first dehumidification heat exchanger and the second dehumidification heat exchanger are provided with solid dehumidification materials. According to the invention, the humidity load in air is processed by the solid dehumidification materials arranged on the surfaces of the dehumidification heat exchangers, the processing of air heat load is realized through the cooling mode of the traditional evaporator; and the separation processing and independent control of the heat humidity load are realized only by adopting one device according to the invention, compared with the traditional composite heat humidity independent control heat pump air-conditioning system, the heat pump system provided by the invention has the obvious advantages of simple structure and low manufacturing cost.

The invention relates to a solar-energy low-temperature thermal power-generation and photovoltaic power-generation combination system, comprising a compound parabolic collector system, a heat storage system, an organic rankine cycle power-generation system, a photovoltaic module and a photovoltaic power-supply system, wherein the compound parabolic collector system comprises a high-temperature end compound parabolic collector array and a low-temperature end compound parabolic collector array, and the photovoltaic module is arranged on the upper part of a heat absorber of the compound parabolic collector; the heat storage system comprises a liquid storage tank in which coil pipes are equally arranged, and PCM (phase change material) is filled in the coil pipes; the organic rankine cycle power-generation system comprises an evaporator, a steam turbine, a generator, a heat regenerator, a condenser, two pumps and six valves. The total power-generation efficiency of the combination system is greatly enhanced; and the adoption of the heat storage system avoids the application of additional accumulators and complicated tracking devices, thus reducing cost; and the adoption of two-class evaporator reduces non-reversibility of heat transmission of heat-exchanging fluid and organic work-medium so as to reduce average running temperature, thus being in favor of prolonging service life of photovoltaic cells.

The invention provides a water-spray screw steam compressor. Three seals are arranged between a working cavity of the compressor and a bearing cavity; steam seal is realized through spraying high-pressure liquid water in space between the first seal and the second seal; besides seal through spraying water, the steam absorbing superheat degree can be lowered through spraying water in a steam absorbing cavity to increase the mass flow rate of compressed steam; or water is sprayed in a compression cavity at the steam absorbing end moment to effectively lower the temperature of compressed steam and the steam discharging superheat degree, so that the working process of the compressor is similar to a constant temperature compression process, and the efficiency of the compressor is improved. A pressure stabilization tank is arranged on the steam discharging side of the compressor; the steam pressure in the pressure stabilization tank is adjusted to ensure efficient operation of the compressor under different working conditions. High-temperature water flowing out of a water route of the pressure stabilization tank is mixed with low-temperature softened water or distilled water, the mixed water enters a heat exchanger and is recycled to provide the steam heat of a user and to realize steam superheat degree adjustment; adjustment of temperature and flow of sprayed water can be realized through adjusting flow of the softened water, distilled water or water entering the heat exchanger.

The invention discloses a shell and tube sewage heat exchanger. The heat exchanger comprises an external shell and internal heat exchange tubes, wherein the shell is provided with a sewage inlet pipe and a sewage outlet pipe. The heat exchanger is characterized in that: a plurality of parallelly arranged heat exchange tube rows are arranged in the shell; each heat exchange tube row is formed by arranging N heat exchange tubes and is supported and fixed through a supporting and fixing plate connected to the shell; and seal heads are arranged at the two ends of the shell and are connected with the shell through fixed flanges. Compared with the prior art, the invention has the advantages that: sewage can directly enter the heat exchanger without blocking the heat exchanger and can be directly subjected to heat exchange with intermediary water, a secondary refrigerant or a refrigerant without being subjected to any treatment, so that a filtering system is eliminated, higher efficiency andsimplicity are achieved, and manufacturing cost is lower; and the heat exchanger has a detachable structure, can be conveniently maintained, and can meet various engineering requirements.

The invention discloses a loop heat pipe-type cylindrical solar seawater desalination device. The device comprises a cylindrical multiple-effect distiller, a light collection groove and a loop heat pipe. An evaporating pipe of the loop heat pipe is used as a solar heat collecting pipe and a condenser pipe of the loop heat pipe is used as a distiller heating pipe so that characteristics of good heat transfer performance and high integral efficiency are obtained. A heating pipe, a heat-transfer pipe, a semi-circular groove and a nozzle unit are tightly arranged in a heat-insulation cylinder inner-cavity so that a pre-heating chamber, a distillation chamber, a seawater tank and a fresh water tank are formed and thus the distiller structure is very compact, can be processed easily and is suitable for standard production. The distiller has the characteristics of repeated use of vaporization latent heat, reinforcement of inner heat and mass transfer processes and improvement of an operation temperature. The heat transfer areas of the distillation chamber are increased from inside to outside so that a small heat transfer temperature difference is kept, the whole distiller effective number is improved and a concentration ratio and a water yield are further improved. The loop heat pipe-type cylindrical solar seawater desalination device is suitable for low-cost modularization production and can be widely used in the field of solar energy seawater desalination.

The invention discloses a cold and hot water supply device by compositely utilizing energy. The device comprises four parts, i.e. a heat pump sub hot water system, a water tank subsystem, a heat-utilization heat-transfer subsystem and a solar photovoltaic power generation subsystem. A water distributor in a water tank of the device can be effectively controlled to realize the partition distribution of hot water with different temperatures, the water with higher temperature is located in a hot water area, and the water with lower temperature is located in a freeze water area, so that the economy and stability of the hot water supply system can be guaranteed. Heat quantity generated in solar photovoltaic power generation can be effectively utilized to improve the water supply temperature of the condensation side of the heat pump circulation, and reduce heat transfer temperature difference; and meanwhile, the domestic hot water and the freeze water can be supplied at the same time, the circulating efficiency of a heat-pump water heater system can be improved and the heat quantity generated in the photovoltaic power generation can be effectively utilized by utilizing a plurality of energy resources including a solar energy, an air source, a ground source and the like.

The invention discloses a method and equipment for preparing hydrocarbon by methyl alcohol or / and dimethyl ether. The invention is mainly characterized in that raw material gases, such as methyl alcohol or / and dimethyl ether and the like pass through fixed bed reaction composition equipment for catalysis to generate hydrocarbon, wherein the fixed bed reaction combination equipment is at least provided with two reaction zones, and each reaction zone is provided with a heat exchange tube set capable of independently adjusting heat exchange medium temperature; after reaction gases separate target product hydrocarbon and water by heat exchange and cooling, expect that less chillout recycle gas is mixed with raw material gas, reaction for generating target product hydrocarbon is carried out.The invention has the beneficial effects of small catalyst layer temperature difference, low recycle ratio, high synthetic ratio, small investment, high output, energy saving and consumption reduction.

The present invention is fluid ice making method and apparatus. The method includes cooling the cool carrying medium in fluid to below 0 deg.c with evaporator, spraying ice making water to the cooled cool carrying medium in fluid to form mixed fluid of ice grain and cool carrying medium and separating ice from the cool carrying medium in fluid to obtain fluid ice. The apparatus for making fluid ice includes evaporator, ice making unit, water sprayer, filter with filtering net and circulating pump connected via pipeline. The present invention has high heat efficiency, high practicality, simple structure and low running cost.

The invention discloses a method for producing hydrocarbon with synthetic gas, which comprises essentially the steps as follows: methanol synthetic reaction of the pressurized synthetic gas is implemented in a methanol synthetic reactor, reaction gas is not separated after being output from a reaction tower and enters a methanol dehydrating reactor under the same pressure level so as to implement the methanol dehydrating reaction and generate the hydrocarbon product, the final reaction gas is cooled and separated so as to generate the hydrocarbon product, water and unreacted synthetic gas, and the separated synthetic gas is either discharged for gas-steam integrated gasification combined cycle (IGCC) or taken as recycled synthetic gas and mixed with the raw material synthetic gas in further methanol synthesis, methanol dehydration and product separation besides little discharge.

The invention pertains to heating and hot water supply field, relating to a high efficiency large temperature rise compression heat pump set with a big inlet-outlet temperature difference at both a heat sink side and a head source side. The large temperature rise compression heat pump set is configured by assembling two water source heat pump devices, and each heat pump set comprises separately in series or in parallel a compressor, a condenser, an evaporator, a subcooler, and a throttling device, or an added economizer, and forms a separate working medium circulation loop. The inventive large temperature rise compression heat pump set can heat returned hot water step by step from a low temperature to a high temperature, the cold water is cooled step by step in a reverse direction of the temperature rise of the cooling water, and temperature difference between the hot water and cold water at the inlet and outlet of the heat pump is enlarged; and the performance coefficient of the heat pump set is further enhanced comparing with a simple two-stage compression heat pump in series, so that the comprehensive energy utilization efficiency and economy of the inventive system are increased greatly comparing with a common heat pump set.

The invention discloses an efficient condenser which comprises a shell. A condensation heat exchange area and a supercooling area are formed in the shell from top to bottom through a plurality of heat exchange pipes and a supercooling pipe. The condensation heat exchange area is divided into an upper layer and a lower layer. The heat exchange pipes on the upper layer and the lower layer are separated by a fluid baffle penetrating through supporting plates. The whole fluid baffle tilts by 10-15 degrees towards one side in the width direction. The condensation heat exchange area and the supercooling area are separated by a supercooling area upper sealing plate covering the supercooling area. According to the efficient condenser, due to the fact that the fluid baffle is arranged between the upper layer and the lower layer of the condensation heat exchange area and the supercooling area upper sealing plate is arranged between the condensation heat exchange area and the supercooling area, the thickness of fluid films outside the heat exchange pipes below the fluid baffle is effectively reduced, the heat exchange performance of the supercooling area is enhanced, and the energy efficiency of a refrigeration system is obviously improved.

The invention provides a method for air separation production on the liquid oxygen and the liquid nitrogen through the LNG (Liquefied Natural Gas) cold energy. According to the all-liquid air separation method, the investment is less, the energy-saving rate is high, the energy consumption is low, the cold loss is small, the output of the liquid nitrogen and the liquid oxygen is large, and the production cost can be greatly reduced. According to the technical scheme, the implementation steps of the method includes that the raw nitrogen from an air separation tower cold box is reheated through a main heat exchanger cold box to join the medium-pressure and low-temperature nitrogen separated through a gas and liquid separation tank to be reheated through a circulating heat exchanger cold box, the reheated low-pressure and low-temperature nitrogen is reheated through the circulating heat exchanger cold box, and the medium-pressure and normal-temperature nitrogen boosted through a nitrogen booster enters a circulating nitrogen booster to be boosted into the high-pressure nitrogen; the high-pressure nitrogen is precooled through the circulating heat exchanger cold box; the precooled high-pressure nitrogen is fed into the air separation tower cold box to serve as an air separation cold source, the high-purity and high-pressure liquid nitrogen is obtained at the bottom of an upper tower of an LNG cold energy recovery tower cold box, the high-pressure liquid nitrogen is throttled through a throttling valve to obtain the medium-pressure liquid nitrogen and the medium-pressure nitrogen, and the medium-pressure liquid nitrogen and the medium-pressure nitrogen are throttled through the throttling valve to obtain a low-pressure liquid nitrogen product and the low-pressure nitrogen.

The invention provides a case-type multi-shell-pass countercurrent speedup type shell and tube heat exchanger. The heat exchanger comprises a shell (5), wherein one end of the shell is provided with a tube plate I (3); a tube case (2) is connected outside the tube plate I (3), and a baffle is arranged inside the tube case; the other end of the shell is provided with an end cover (11); a heat exchange tube (6) is arranged in the shell; the shell of the heat exchanger has a round-upside square-downside structure or a square-upside round downside structure; at least one layer of vertical countercurrent speedup guide plate (7) is arranged in the shell; and the inner part of the shell is separated into at least two shell passes to ensure that the number of pass of fluid outside a tube is the same as that of fluid in the tube, and the fluid outside the tube and the fluid in the tube have opposite flowing dictions along the axial direction. The heat exchanger can make the direction of the fluid along the axial direction in the shell pass in the shell and tube heat exchanger opposite to that of the fluid in the tube, make the fluids quickly flow for heat exchange, reduce heat transfer temperature difference of the fluids, improve heat exchange efficiency, and realize synchronous composite utilization of double heat sources. The special shell structure ensures more compactness in heat exchange tube arrangement, can effectively reduce the volume of the heat exchanger, and reduces the filling amount of a refrigerant.

The invention provides a sectional evaporation-compression vapor compression heat pump, belonging to the technical field of residual-heat utilization and heat pump / refrigeration. The vapor compression heat pump aims at overcoming the defects of a vapor compressor provided with a single evaporator when a residual-heat medium has large temperature variation range, and provides a vapor compression machine set which comprises more than two compressors, more than two evaporators, a condenser, a throttle valve and the like and realizes sectional evaporation-compression; low temperature section evaporation-compression can be realized by the low temperature evaporator and the first compressor; high temperature section evaporation-compression can be realized by the high temperature evaporator and the second compressor; the residual-heat medium firstly flows through heating refrigerant liquid of the high temperature evaporator to become refrigerant vapor to be provided for the second compressor, and then flows through heating refrigerant liquid of the low temperature evaporator to become refrigerant vapor to be provided for the first compressor after the temperature is lowered, the first compressor provides the refrigerant vapor for the condenser or the second compressor; and the heat of the heated medium is absorbed by the condenser when the medium flows through the condenser. The sectional evaporation-compression vapor compression heat pump reduces residual-heat transmission temperature difference, improves the performance index of the machine set, and can reduce the power consumption of the machine set when the residual-heat medium has large temperature variation range.

The invention relates to a method for producing hydrocarbon by Fishcer-Tropsch reaction of synthesis gas, comprising the following steps: firstly, under the pressurizing, the synthesis gas containing hydrogen and carbon monoxide carries out Fishcer-Tropsch synthetic reaction in a Fishcer-Tropsch synthetic reactor 201 which has at least two zones capable of independently adjusting vaporizing temperature of cooling medium and preferably adopts a water cooling heat exchanging pipe set with the front-low rear-high temperature; tower reaction gas is cooled and separated or enters a hydrocarbon modifying reactor 202 with molecular sieve to carry out hydrocarbon modification, final reaction gas is cooled to separate hydrocarbon, water and unreacted synthesis gas, the separated synthesis gas is discharged to gas / steam for integral circulation generating (IGCC), or the separated synthesis gas is used as circulation synthesis gas to be mixed with the synthesis gas of raw materials except a little discharged separated synthesis gas, and the Fishcer-Tropsch reaction and product separation are carried out again.

The invention discloses a three-temperature section food quick freezing method and a three-temperature section food quick freezer, aiming to reduce the power consumption of a refrigerating system in the quick freezing process and achieve the purpose of energy saving. The quick freezer comprises an quick freezer body and a refrigerating system, wherein the inside of the quick freezer body is provided with a food delivery device; the quick freezer body is provided with a feed port and a discharge port; the inside of the quick freezer body is separated into three chambers including a precooling chamber, a crystallization chamber and a cryogenic chamber in sequence by insulating materials or metal partitions; and the insides of the precooling chamber, the crystallization chamber and the cryogenic chamber are respectively provided with an evaporator and a cooling fan. By using the quick freezing method and the quick freezer, food passes through the precooling chamber, the crystallization chamber and the cryogenic chamber with three temperature sections in sequence to become quick-frozen food, the temperature distribution in each chamber is more uniform, and the temperature difference is small, thereby achieving the purpose of energy saving.