Background
In recent years, with the continuous development of urban construction in China, the contradiction between regional development and heat supply demand is increasingly prominent. The areas of all urban areas are continuously enlarged, the large-scale subdistricts of main urban areas are continuously increased, the areas of old urban areas are greatly increased every year, and the areas of new urban areas are also continuously enlarged. From the heat source and the heat supply capacity of the heat supply network in the current city, the demand of rapid development of the city can not be met far away. If the heat supply cannot be kept up with, the urban development will be subjected to bottlenecks.
In order to solve the contradiction between urban development and the benefit of common people, central heating engineering construction, newly increased heating area and newly increased engineering investment are generally started in various places. The method specifically comprises newly-built pipe network engineering, part of old network reconstruction engineering, newly-built relay pump stations, centralized control dispatching centers, newly-built heat exchange stations, heat exchange station reconstruction engineering and the like.
The heat supply transformation project is divided into a heat source side and a heat network side.
The heat source side generally comprises unit heat supply reconstruction and heat supply initial station construction projects, specifically, a newly-added network-accessing heat supply area of a power plant and a heat and power company, a heat supply area of a heat supply network of a new urban boiler room, a heat supply area of a heat supply network of a regional heat supply company and the like.
The heat supply network side is mainly used for replacing pipelines which are in service in the old city in an overdue mode, leakage can be effectively controlled after the heat supply pipelines are replaced, the number of times of heat outage caused by leakage of the pipelines is greatly reduced, and the heat supply effect is greatly improved.
Central heating is realized in 9 months in 1983 in a certain old city, and a pipe network is operated for 27 years at present. The measurement shows that the pipe diameter of an old pipe network installed in 1985 is reduced to 4-6mm from 10mm in the original installation, the local corrosion is serious, and the leakage phenomenon often occurs in the heat supply period. The pipeline of the heat supply pipeline network part is out of service for a long time, and the leakage phenomenon of the pipeline often occurs during the heat supply period, so that the heat supply quality is reduced. If not modified, once the pipeline leaks, the heat is stopped in stages, which can cause great influence to the life of residents. The heat supply pipe network in the old city is transformed by the investment of a thermoelectric company, all thinned and corroded pipelines are replaced, the total length of the transformation range pipe network is about 5 kilometers, the transformation range relates to a heat supply area of 57 ten thousand square meters, the number of users is about 5000 households, and the capital investment is 1700 ten thousand yuan. After the engineering transformation is completed, the heat supply quality and the heat supply stability of the area are greatly improved. Through the transformation of a pipe network, the heat source of the main urban area is sufficient, and the normal heat supply of residents, shops and enterprises can be borne.
The construction and use life of a heat supply main pipe network of a certain power plant is more than 18 years mostly, and some of the heat supply main pipe networks even have 30 years. The construction time of the partial pipe network is long, and the technical process is lagged behind in the construction period, so that the heat preservation layer and the protection layer are seriously damaged, and the pipe network is seriously aged and corroded. In recent years, the main grid leakage accident frequently occurs, and occurs several tens times per operation period. In the process of rush-repair of the main pipe network, rush-repair personnel face the threat of high-pressure and high-temperature water with the temperature of more than 95 ℃, and the rush-repair water leakage lasts for more than 30 hours each time, so that the serious situation that large-area residential houses stop heating and part of underground pipe networks are frozen and cracked is caused. The problems existing in the aspect of a centralized heat supply secondary network are also more prominent, and especially in early buildings and heat supply buildings of abandoned pipe small boiler rooms which are connected to the grid in recent years, the serious aging and corrosion degree and the large quantity of pipe networks seriously threaten the urban heat supply safety and influence the normal life of resident users.
The length of a heat supply pipe network of a certain heat supply group is 666 kilometers, wherein the length of a primary network is 165 kilometers, and the length of a secondary network is 501 kilometers. Construction was about 400 km before 1995. Most pipe networks are long in construction time and serious in aging corrosion, so that the leakage of a pipe network system is serious, and the heat dissipation loss reaches 0.35 GJ/square meter per year. The average temperature drop of each kilometer of the heating power pipe network is more than 2 ℃, and the average water loss rate of the pipe network system is about 3%. Because the water loss is large, the heat loss is serious, almost all primary networks and secondary networks have hydraulic imbalance problems of different degrees, and the pipe networks are aged and cannot be scientifically adjusted, so that the heat supply quality of users is difficult to guarantee in heat supply of heat supply enterprises.
For decades, the central heating industry has made a great contribution to the development and construction of cities and the improvement of the living standard of people in China. Nowadays, the aging and the corrosion of a large-area central heating pipe network become prominent problems influencing the central heating, and the heat supply safety of cities and the normal life of common people are seriously threatened.
The implementation of the transformation of the centralized heat supply pipe network is an urgent task for doing well of urban heat supply. The leakage of the pipe network can be greatly reduced through the improvement of the pipe network, the energy consumption is reduced, the energy is saved, and the energy utilization rate is improved; the heat supply enterprises can apply new technology and new process in a large amount through the transformation of the pipe network, the scientific regulation capacity of the heat supply enterprises is improved, and the overall heat supply level is improved; can promote heating system safety and heat supply guarantee ability comprehensively through the pipe network transformation, constantly improve the thermal mass of using of vast resident's user, benefit the common people. The implementation of the transformation of the centralized heat supply pipe network is beneficial to the nation and the people, and the implementation is early benefited.
The central heating pipe network reconstruction project is implemented, the key point is to dismantle the waste heating pipeline and lay a new heating pipeline, and huge capital investment is needed. How can one use the existing pipeline, or lay less or thinner pipelines, with less investment, and also can achieve the required heat supply? This is a problem that is often thought by skilled artisans of design and construction.
Disclosure of Invention
The invention provides a direct-connected large-temperature-difference heat exchange device capable of reducing the temperature of return water of a heat supply network so as to increase the heat supply amount of the heat supply network, aiming at newly building or modifying an old heat supply network and solving the problem that the heat supply amount of the heat supply network is insufficient.
The utility model provides a big difference in temperature heat transfer device of direct-connected type, its structure includes: high temperature evaporator, low temperature evaporator, condenser, sprayer, several valves, water pump and some connecting lines.
The working process is
(1) High-temperature hot water from a heat supply pipe network enters a multi-stage high-temperature evaporator for flash evaporation step by step, and the remaining hot water after flash evaporation supplies heat to a heat user;
(2) the hot user heat supply backwater enters a multi-stage low-temperature evaporator for flash evaporation step by step, and the remaining hot water after flash evaporation returns to a heat supply network;
(3) the flash steam of each stage of the high-temperature evaporator is ejector driving steam, and low-pressure steam of each stage of the low-temperature evaporator is ejected to form medium-pressure steam to enter condensing chambers of each stage of the condenser;
(4) the hot user heat supply backwater respectively enters each level of the condenser for spraying, and is heated by the steam entering each level of the condensing chamber to supply heat to the hot user;
(5) the side wall of the last stage of the condenser is provided with a vacuum air pump which is used for pumping out non-condensable gas such as air and the like to maintain the vacuum degree of the whole device;
(6) the structure of the direct-connected large-temperature-difference heat exchange device also comprises a water return device which is connected among the high-temperature evaporator, the low-temperature evaporator and the heat supply pipe network, the direct-connected large-temperature-difference heat exchange device is provided with two water return boxes which work alternately, and the water return device boosts the return water of the heat supply pipe network to return to the heat supply pipe network by utilizing the pressure of the water coming from the heat supply pipe network.
The high-temperature evaporator is a vertical pressure container in appearance, and structurally comprises: the device comprises a water inlet, an upper sealing head, a first-stage steam outlet, a first-stage sieve plate, a first-stage evaporation chamber, a barrel, a second-stage sieve plate, a second-stage evaporation chamber, a second-stage steam outlet, a third-stage sieve plate, a third-stage evaporation chamber, a third-stage steam outlet, a lower sealing head and a water outlet.
High-temperature hot water from a heat supply pipe network passes through a water return device, enters a first-stage evaporation chamber of a high-temperature evaporator through a water inlet at the top of an upper end socket of the high-temperature evaporator, is sprayed downwards through a plurality of pore channels of a first-stage sieve plate and then is flashed immediately, and generated steam flows out through a first-stage steam outlet and enters a first-stage ejector; residual hot water is evaporated, and the residual hot water is sprayed downwards through a second-stage sieve plate and flows into a second-stage evaporation chamber; the same process is carried out in the second-stage evaporation chamber and the third-stage evaporation chamber in sequence; and finally, the residual hot water subjected to multistage evaporation flows out from an outlet at the bottom of the high-temperature evaporator to supply heat to a heat user.
The low-temperature evaporator is a vertical pressure container in appearance, and structurally comprises: the device comprises a water inlet, an upper sealing head, a first-stage steam outlet, a first-stage sieve plate, a first-stage evaporation chamber, a barrel, a second-stage sieve plate, a second-stage evaporation chamber, a second-stage steam outlet, a third-stage sieve plate, a third-stage evaporation chamber, a third-stage steam outlet, a lower sealing head and a water outlet.
Hot user heat supply backwater enters a first-stage evaporation chamber of the low-temperature evaporator from a water inlet at the top of an upper seal head of the low-temperature evaporator, is sprayed downwards through a plurality of pore channels of a first-stage sieve plate and then is flashed immediately, and generated steam flows out through a first-stage steam outlet and enters a first-stage ejector; residual hot water is evaporated, and the residual hot water is sprayed downwards through a second-stage sieve plate and flows into a second-stage evaporation chamber; the same process is carried out in the second-stage evaporation chamber and the third-stage evaporation chamber in sequence; and finally, the residual hot water after the heat supply backwater of the heat user is subjected to multistage evaporation flows out from the bottom outlet of the low-temperature evaporator, flows through the backwater device and returns to the heat supply network.
The condenser is a vertical pressure container in appearance, and the structure of the condenser comprises: the device comprises an upper end enclosure, a first-stage steam inlet, a first-stage sieve plate, a first-stage water inlet, a first-stage condensation chamber, a barrel, a first-stage bottom plate, a first-stage drain pipe, a second-stage sieve plate, a second-stage water inlet, a second-stage condensation chamber, a second-stage steam inlet, a second-stage bottom plate, a second-stage water delivery pipe, a third-stage sieve plate, a third-stage water inlet, a third-stage condensation chamber, a third-stage steam inlet, a lower end enclosure, a water outlet and a vacuum air pump.
The condenser is provided with a plurality of stages of condensing chambers, and the condensing chambers of each stage are connected in parallel; the heat supply backwater of the heat user is divided into a plurality of paths which respectively enter different condensation chambers: the first path enters a first-stage condensation chamber of the condenser, is sprayed downwards from a first-stage sieve plate, steam entering the first-stage condensation chamber heats sprayed water, and heated hot water falls on a first-stage bottom plate and flows to a lower end enclosure from a first-stage drain pipe; the second path enters a second-stage condensation chamber of the condenser, sprays downwards from a second-stage sieve plate, steam entering the second-stage condensation chamber heats spray water, and hot water falls on a second-stage bottom plate and flows to a lower end enclosure from a second-stage drain pipe; the third path enters a third-stage condensation chamber, and is sprayed downwards from a third-stage sieve plate, steam entering the third-stage condensation chamber heats spray water, and hot water falls on a lower seal head; hot water accumulated on the lower end enclosure flows out through a water outlet at the bottom of the condenser to supply heat to a heat user; and a vacuum air pump is arranged on the side wall of the third-stage condensation chamber.
The ejector, its structure includes: the steam inlet, the nozzle, the suction chamber, the suction inlet, the diffuser pipe and the diffuser pipe outlet.
High-temperature high-pressure steam generated by the high-temperature evaporator is used as driving steam of the ejector, passes through the steam inlet and the nozzle, is sprayed at a high speed to enter the suction chamber, and due to the high-speed spraying effect of the driving steam, the inside of the suction chamber presents a low-pressure space, low-temperature steam generated by the low-temperature evaporator enters the suction chamber from the suction inlet, and the high-temperature driving steam wraps the low-temperature suction steam to flow at a high speed together, is subjected to speed reduction and pressure rise through the diffuser pipe, and is discharged from the outlet of the diffuser pipe.
The structure of the water return device comprises two water return tanks, a water feeding pump, a pipeline and a plurality of valves.
Wherein the structure of first water return tank includes: the hot-water supply system comprises a hot-water supply network inlet, a first electric valve, a second electric valve, a box body, a hot-water space, a water piston, a low-temperature hot-water space, a first one-way valve, a second one-way valve and a hot-water supply network return port.
The structure of second return water tank includes: the hot water outlet, the third electric valve, the fourth electric valve, the box body, the hot water space, the water piston, the low-temperature hot water space, the third check valve, the fourth check valve, the water return pump and the hot water inlet.
The working flow of the water return device is as follows:
(1) high-temperature hot water of the heat supply pipe network flows in from a water inlet of the heat supply network and enters a hot water space of a first water return tank through a first electric valve, the high-temperature hot water pushes a water piston to move downwards, and the water piston pushes low-temperature hot water in the low-temperature hot water space downwards and returns to a water return pipeline of the heat supply network through a first one-way valve and a water return port of the heat supply network;
(2) residual hot water after flash evaporation in the low-temperature evaporator, namely low-temperature hot water, enters a low-temperature hot water space of the second water return tank from the bottom through a water return pump and a fourth one-way valve, and pushes a water piston upwards, and the water piston pushes high-temperature hot water in the hot water space upwards and sends the high-temperature hot water to the high-temperature evaporator through a fourth electric valve;
(3) the residual hot water flash evaporated by the low-temperature evaporator, namely low-temperature hot water, enters a low-temperature hot water space of the first water return tank from the bottom through a water return pump and a second one-way valve, the low-temperature hot water pushes a water piston upwards, the water piston pushes high-temperature hot water in the hot water space upwards, and the high-temperature hot water is sent to the high-temperature evaporator through a second electric valve;
(4) the high-temperature hot water of the heating pipe network enters the hot water space of the second water return tank through the third electric valve, the water piston is pushed to move downwards, and the low-temperature hot water of the low-temperature hot water space is pushed downwards by the water piston and returns to the water return pipeline of the heating pipe network through the third one-way valve.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
FIG. 1 is a general diagram of an embodiment of the direct-connected large temperature difference heat exchange device.
The general structure of the embodiment of the direct-connected large-temperature-difference heat exchange device comprises the following components in part by weight: a water return 100, a high temperature evaporator 200, a low temperature evaporator 300, a condenser 400, an ejector 500, several valves, a water pump, and some connecting lines. In appearance, the block is divided into four blocks from left to right: 1, a water return device 100; 2, a vertical multistage high-temperature evaporator 200; 3, a vertical multi-stage low-temperature evaporator 300; 4, vertical multistage condenser 400. There is a horizontal steam ejector 500 between each stage of the high temperature evaporator 200, the low temperature evaporator 300, and the condenser 400.
The working process is
1, high-temperature hot water with certain pressure from a heat supply network flows in from a water inlet 101 of the heat supply network, passes through a water return device 100, passes through a hot water outlet 102, and enters a high-temperature evaporator 200;
2, the high-temperature evaporator 200 is a multi-stage evaporator, hot water is flashed in the high-temperature evaporator 200 from top to bottom step by step, wherein first-stage flash steam flows out from a steam outlet 205;
3, the residual hot water after the gradual flash evaporation flows out from the bottom of the high-temperature evaporator 200, passes through the water feeding pump 230, flows out from the heat supply water outlet 602, and supplies heat to a heat user;
4, hot user heat supply backwater, which is low-temperature hot water, enters from the heat supply backwater port 601, passes through the valve 320, and enters the low-temperature evaporator 300;
5, the low-temperature evaporator 300 is a multi-stage evaporator, the heating water and the return water are flashed in the low-temperature evaporator 300 from top to bottom step by step, wherein the first-stage flash steam flows out from the steam outlet 305;
6, the residual hot water after the gradual flash evaporation of the heat supply return water is low-temperature hot water, flows out from the bottom of the low-temperature evaporator 300, flows through the water return device 100 from the hot water inlet 103, and returns to the heat supply network from the heat supply network water return port 104;
7, the ejector 500 uses the first-stage flash steam of the high-temperature evaporator 200 as driving steam to inject low-pressure steam at the first-stage steam outlet 305 of the low-temperature evaporator 300, the low-pressure steam and the low-pressure steam are mixed to form medium-pressure steam, and the medium-pressure steam is ejected from the outlet of the ejector 500 and enters the first-stage steam inlet 405 of the condenser 400;
8, the high-temperature evaporator 200 is a multi-stage evaporator, the second and third stage flash steam respectively flows out from the second and third stage steam outlets and respectively enters the second and third stage ejectors as driving steam to inject the second and third stage low-pressure steam of the low-temperature evaporator 300, the low-pressure steam and the driving steam are mixed to form medium-pressure steam, and the medium-pressure steam is ejected from the ejector outlets and respectively enters the second and third stage steam inlets of the condenser 400;
9, the condenser 400 is a multi-stage condenser, and the heat supply backwater of the heat user enters from the heat supply backwater port 601, and respectively enters into each stage of the condenser for spraying through the valve 450 and the branch valves. The medium pressure steam entering the condenser 400 from the steam inlet of each stage heats the sprayed heat supply backwater in a contact manner, and the heated heat supply hot water flows out from the bottom of the condenser and reaches the heat supply water outlet 602 through the water supply pump 460 to supply heat to the heat user. And a vacuum air pump is arranged on the side wall of the last stage of the condenser to pump out non-condensable gases such as air and maintain the vacuum degree of the whole equipment.
Fig. 2 shows a structure diagram of a high-temperature evaporator of an embodiment of the direct-connection type large-temperature-difference heat exchange device.
The high-temperature evaporator of the embodiment of the direct-connected large-temperature-difference heat exchange device is a vertical pressure container in appearance, and structurally comprises: the device comprises a water inlet 201, an upper seal head 202, a first-stage steam outlet 205, a first-stage sieve plate 210, a first-stage evaporation chamber 206, a cylinder 203, a second-stage sieve plate 220, a second-stage evaporation chamber 216, a second-stage steam outlet 215, a third-stage sieve plate 230, a third-stage evaporation chamber 226, a third-stage steam outlet 225, a lower seal head 235 and a water outlet 240.
High-temperature hot water with certain pressure from a heat supply pipe network passes through a water return device, enters the high-temperature evaporator through a water inlet 201 at the top of an upper end enclosure 202 of the high-temperature evaporator, is sprayed downwards through a plurality of pore channels of a first-stage sieve plate 210, and then enters a first-stage evaporation chamber 206 in the high-temperature evaporator downwards.
Because the first-stage steam outlet 205 of the first-stage evaporation chamber 206 is connected with the condenser in a vacuum state through the ejector, and the pressure in the first-stage evaporation chamber 206 is lower than the saturation pressure corresponding to the temperature of the sprayed hot water, the hot water enters the first-stage evaporation chamber 206 and is immediately flashed after being sprayed, and part of the hot water is evaporated into steam. The steam generated by the evaporation in the first stage evaporation chamber 206 flows out through the first stage steam outlet 205 and enters the first stage ejector. The residual hot water after evaporation is sprayed downwards through the second-stage sieve plate 220 and flows into the second-stage evaporation chamber.
The same process is performed in the second-stage evaporation chamber 216 and the third-stage evaporation chamber 226 in sequence.
Finally, high-temperature hot water is supplied from the heat supply pipe network, and although the high-temperature hot water is residual hot water subjected to multi-stage evaporation, the high-temperature hot water still has higher temperature and flows downwards from the water outlet 240 at the lower part to directly supply heat to heat users.
The sieve plate is a perforated plate and has the following functions:
1, for given water flow, calculating the total flow area of sieve pores, and ensuring that the thickness of a water layer on a sieve plate is not less than 5 cm so as to ensure that vapor phase spaces of an upper evaporation chamber and a lower evaporation chamber are not communicated;
2, the surface of the water flow sprayed and flowed down from the sieve plate has enough area to ensure the heat exchange requirement of water evaporation;
3, the diameter of the water flow through holes on the sieve plate is generally 6-8 mm and cannot be 6mm smaller, so that blockage is prevented.
Fig. 3 shows a structure diagram of a low-temperature evaporator of the embodiment of the direct-connection type large temperature difference heat exchange device.
The low-temperature evaporator of the embodiment of the direct-connected large-temperature-difference heat exchange device is a vertical pressure container in appearance, and structurally comprises: the device comprises a water inlet 301, an upper sealing head 302, a first-stage steam outlet 305, a first-stage sieve plate 310, a first-stage evaporation chamber 306, a cylinder 303, a second-stage sieve plate 320, a second-stage evaporation chamber 316, a second-stage steam outlet 315, a third-stage sieve plate 330, a third-stage evaporation chamber 326, a third-stage steam outlet 325, a lower sealing head 335 and a water outlet 340.
The hot water with lower temperature enters from the hot water return port, passes through the valve, and enters into the low-temperature evaporator from the water inlet 301 at the top of the upper end enclosure 302 of the low-temperature evaporator.
The low-temperature evaporator is a multi-stage evaporator, and heat supply backwater is flashed in the low-temperature evaporator from top to bottom step by step.
First, the primary screen deck 310 sprays down the plurality of openings into the primary evaporation chamber 306.
Because the first-stage steam outlet 305 of the first-stage evaporation chamber 306 is connected with the ejector suction chamber, the suction chamber is in a vacuum state, and the pressure in the first-stage evaporation chamber 306 is influenced to be lower than the saturation pressure corresponding to the temperature of the sprayed hot water, the hot water is sprayed into the first-stage evaporation chamber 306 and then is flashed immediately, and part of the hot water is evaporated into steam. The steam generated by the evaporation in the first stage evaporation chamber 306 flows out through the first stage steam outlet 305 and enters the first stage ejector.
The remaining hot water from the first stage evaporation chamber 306 is sprayed down through the plurality of openings in the second stage screen 320 and into the second stage evaporation chamber 316.
The same process is performed in the second-stage evaporation chamber 316 and the third-stage evaporation chamber 326 in sequence.
Finally, the residual hot water of the hot user heat supply backwater is low in temperature due to multi-stage evaporation, and flows out of the water outlet 340 at the lower part after reaching the lower end socket 335, and returns to the heat supply network after flowing through the water returning device.
The sieve plate is a perforated plate and has the following functions:
1, for given water flow, calculating the total flow area of sieve pores, and ensuring that the thickness of a water layer on a sieve plate is not less than 5 cm so as to ensure that vapor phase spaces of an upper evaporation chamber and a lower evaporation chamber are not communicated;
2, the surface of the water flow sprayed and flowed down from the sieve plate has enough area to ensure the heat exchange requirement of water evaporation;
3, the diameter of the water flow through holes on the sieve plate is generally 6-8 mm and cannot be 6mm smaller, so that blockage is prevented.
Fig. 4 shows a structure diagram of a condenser of the embodiment of the direct-connected large temperature difference heat exchange device.
The condenser of the embodiment of the direct-connected large-temperature-difference heat exchange device is a vertical pressure container in appearance, and structurally comprises: the device comprises an upper head 401, a first-stage steam inlet 405, a first-stage sieve plate 406, a first-stage water inlet 410, a first-stage condensation chamber 413, a barrel 407, a first-stage bottom plate 412, a first-stage drain pipe 422, a second-stage sieve plate 416, a second-stage water inlet 420, a second-stage condensation chamber 423, a second-stage steam inlet 415, a second-stage bottom plate 422, a second-stage water conveying pipe 432, a third-stage sieve plate 426, a third-stage water inlet 430, a third-stage condensation chamber 433, a third-stage steam inlet 425, a lower head 435, a water outlet 440 and a vacuum suction pump 450.
The condenser is a multi-stage condenser, but the condensing chambers of each stage are connected in parallel.
The heat supply backwater of the heat user enters from the heat supply backwater port and then is divided into a plurality of paths of flows, and the flows enter different condensing chambers respectively to carry out the heating process.
One of the streams passes through a first stage water inlet 410 and enters a first stage condensation chamber 413 of the condenser, and is sprayed downwardly from a plurality of openings in the first stage screen 406. The medium pressure steam entering the ejector of the first-stage condensation chamber 413 of the condenser from the first-stage steam inlet 405 heats the sprayed heat supply backwater in a contact manner, and the heated heat supply backwater falls on the first-stage bottom plate 412 and then flows to the lower end enclosure 435 from the first-stage drain pipe 422.
The other path of the hot user heat supply backwater enters the second-stage condensation chamber 423 of the condenser through the second-stage water inlet 420 and is sprayed downwards from a plurality of pore channels of the second-stage sieve plate 416 to flow. The middle pressure steam entering the ejector of the second-stage condensation chamber 423 of the condenser from the second-stage steam inlet 415 heats the sprayed hot supply backwater in a contact manner, and the heated hot supply water falls on the second-stage bottom plate 422 and then flows to the lower end enclosure 435 from the second-stage drain pipe 432.
The third path of the hot user heat supply backwater enters the third stage condensation chamber 433 of the condenser through the third stage water inlet 430, and is sprayed downwards from a plurality of holes of the third stage sieve plate 426 to flow. The medium-pressure steam entering the ejector of the third-stage condensation chamber 433 of the condenser from the third-stage steam inlet 425 contacts and heats the sprayed heat supply backwater, and the heated heat supply backwater falls on the lower end enclosure 435.
The hot water accumulated on the lower head 435 finally flows out through the water outlet 440 at the bottom of the condenser.
The side wall of the third stage condensation chamber of the condenser is provided with a vacuum air pump 450 for pumping out non-condensable gases such as air and maintaining the vacuum degree of the whole equipment.
The condenser with parallel condensing chambers is used for ensuring that the lowest pressure exists in each condensing chamber, so that the condenser acts on a suction chamber of the ejector, can more effectively eject the low-temperature evaporator, ensures that the evaporation of the heat supply return water has the maximum temperature drop, and ensures that the traditional heat supply pipe network can provide the maximum heat supply amount.
Fig. 5 shows a structure diagram of an ejector of the embodiment of the direct-connection type large-temperature-difference heat exchange device.
The structure of the steam ejector of the embodiment of the direct-connected large-temperature-difference heat exchange device comprises the following components: a steam inlet 501, a nozzle 505, a suction chamber 510, a suction inlet 520, a diffuser pipe 515, and a diffuser pipe outlet 516.
The high-temperature and high-pressure steam generated by the high-temperature evaporator is injected into the suction chamber 510 at a high speed through the nozzle 505 as the driving steam of the ejector through the steam inlet 501. Due to the effect of the high velocity jet of drive vapor, a low pressure space is presented inside the suction chamber 510 according to the bernoulli force fluid equation. The low-temperature vapor generated from the low-temperature evaporator enters the suction chamber 510 through the suction port 520 by the vapor pressure difference. In the suction chamber 510, the high-speed driving steam is sucked and wrapped by the pumped low-temperature steam, in the common high-speed flow, the two kinds of steam are mixed, equalized in speed and pressure, and then are decelerated and pressurized by the reducing pipe, the throat pipe and the expanding pipe of the diffuser pipe 515 to form uniformly mixed medium-pressure steam, and then the medium-pressure steam is discharged through the diffuser pipe outlet 516.
FIG. 6 shows a structure diagram of a water return device in an embodiment of the direct-connection type large temperature difference heat exchange device of the invention.
The invention relates to a water return device of a direct-connected large-temperature-difference heat exchange device embodiment, which is a self-service power device for hot water circulation between the direct-connected large-temperature-difference heat exchange device embodiment and a heat supply pipe network. The pressure of the incoming water of the heat supply network is used for doing work, and the return water of the heat supply network with insufficient boosting pressure returns to the pipeline of the heat supply network.
The invention relates to a water return device of a direct-connected large-temperature-difference heat exchange device.
The first water returning tank 130 has a structure including: a heat supply network water inlet 101, a first electric valve 131, a second electric valve 132, a box body, a hot water space 133, a water piston 134, a low-temperature hot water space 135, a first check valve 136, a second check valve 137 and a heat supply network water return port 104;
the second return tank 160 has a structure including: a hot water outlet 102, a third electric valve 161, a fourth electric valve 162, a box body, a hot water space 163, a water piston 164, a low-temperature hot water space 165, a third check valve 166, a fourth check valve 167, a return pump 110 and a hot water inlet 103.
The water return device has two working processes which are carried out alternately:
the first working process is that the water piston of the first water return tank descends, and simultaneously, the water piston of the second water return tank ascends, specifically
1, high-temperature hot water with certain pressure from a heat supply pipe network flows into a water inlet 101 from the heat supply pipe network and enters a first water return tank 130 through a first electric valve 131 on an upper end socket of a tank body. The first water return tank body is a vertical pressure container, and a hot water space 133 is arranged above the first water return tank body; a water piston 134 is arranged in the middle and can move up and down along with water flow; below the water piston 134 is a low temperature hot water space 135.
2, the high temperature hot water entering the first return water tank hot water space 133 has a higher pressure, which pushes the water piston 134 downward to move downward, and the water piston 134 pushes the existing low temperature hot water in the low temperature hot water space 135 downward, through the first check valve 136, through the heat supply network return water port 104, and back to the return water pipe of the heat supply network.
3, the residual hot water after the gradual flash evaporation in the low-temperature evaporator, i.e. the low-temperature hot water, flows into the water return device from the hot water inlet 103, is pressurized by the water return pump 110, passes through the fourth check valve 167, enters the low-temperature hot water space 165 of the second water return tank 160 from the bottom, pushes the water piston 164 upwards, and the water piston 164 pushes the existing high-temperature hot water in the hot water space 163 upwards, passes through the fourth electric valve 162, and flows out from the hot water outlet 102 to the high-temperature evaporator.
The second working process is that the water piston of the first water return tank rises and the water piston of the second water return tank descends at the same time, specifically
1, residual hot water after flash evaporation step by step in the low-temperature evaporator, namely low-temperature hot water, flows into the water return device from the hot water inlet 103, is pressurized by the water return pump 110, enters the low-temperature hot water space 135 of the first water return tank 130 from the bottom through the second one-way valve 137, pushes the water piston 134 upwards, pushes the existing high-temperature hot water in the hot water space 133 upwards through the second electric valve 132, flows out from the hot water outlet 102, and is sent to the high-temperature evaporator.
2, the high temperature hot water with a certain pressure from the heating network flows in from the hot network water inlet 101, and enters the hot water space 163 of the second water return tank 160 through the third electric valve 161 on the box body end. A hot water space 163 is arranged above the inside of the second water return tank; a water piston 164 is arranged in the middle; below the water piston 164 is a low temperature hot water space 165.
3, the high temperature hot water entering the second return tank hot water space 163 has a higher pressure, which pushes the water piston 164 downward, and the water piston 164 pushes the existing low temperature hot water in the low temperature hot water space 165 downward, and the low temperature hot water passes through the third check valve 166 and returns to the heat supply network return pipe through the heat supply network return port 104.
And after the second working process is finished, the first working process is repeated, the two working processes are alternately carried out, and the hot water circulation process between the heat supply pipe network and the direct-connected large temperature difference heat exchange device is jointly completed.