A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat

Abstract

The present invention discloses a steam jet vacuum pump unit that utilizes process waste heat and exhaust steam waste heat, including: a hot water tank A warehouse, which is used to hold heat source water. A hot water tank B warehouse, which is used to hold sub-low temperature water. The steam jet vacuum pump unit is arranged in multiple stages and is connected in series from front to back. Each stage is composed of a condenser and a jet pump connected in series from front to back; wherein the outlet of the last-stage jet pump is connected to the hot water tank A warehouse through a pipeline, so as to introduce waste steam into the heat source water in the hot water tank A warehouse. An absorption refrigeration machine, the inlet and outlet ends of its evaporator are respectively connected to the hot water tank B warehouse and the hot water tank D warehouse pipelines to form a low-temperature water circulation channel, and low-temperature water is obtained at the outlet end after the low-temperature water is cooled therein. The vacuum pump unit utilizes the heat of the unpressurized waste steam to produce low-temperature water that cannot be stably supplied by the natural environment, and uses it as cooling water for the condenser, thereby saving working steam and cooling water.

Description

Technical Field

[0001] The invention belongs to the technical field of waste heat utilization, and in particular relates to a steam jet vacuum pump unit utilizing process waste heat and exhaust steam waste heat. Background Art

[0002] Steam jet vacuum pumps are widely used in many industrial fields, such as vacuum degassing of molten steel, concentration of pharmaceutical raw materials, purification of natural pigments, molecular distillation, petroleum distillation, fractionation, urea synthesis and granulation, edible oil refining, aerospace and aircraft engine high-altitude simulation platform, etc.

[0003] Steam jet vacuum pump has two application forms: steam jet vacuum pump unit and steam jet water ring vacuum pump unit. Only in the last stage of the steam jet vacuum pump unit is there a large amount of steam discharged, and at the same time there is a large amount of waste heat to be utilized in the production process.

[0004] There are two types of steam jet vacuum pump units currently in use: domestic and imported. Their steam and cooling water consumption indicators are basically the same, with little difference. Imported steam jet vacuum pump units usually use a relatively high steam pressure of 1.0-1.4MPa.G; the steam pressure of domestic vacuum pumps is generally 0.8--1.2MPa.G. Both use 35-degree normal temperature water inlet.

[0005] However, the working pressure of the No. 1 condenser must be higher than the saturated steam pressure of the 35-degree inlet water. Before the No. 1 condenser, the steam consumption and cooling water consumption of both the two-stage booster ejector and the three-stage booster ejector are very high. In addition, in the hot and humid weather in summer, the efficiency of the cooling tower is reduced, and the cooling water exceeds 35 degrees, which seriously affects the vacuum degree required by the process and causes a sharp increase in the product failure rate. In addition, the waste steam discharged by the final-stage ejector pump is discharged into the final-stage condenser and condensed by the cooling water. The heat content of the discharged waste steam is very high and requires a large amount of cooling water to condense, and then it is sent to the cooling tower for cooling. On the one hand, it increases the load and cooling water volume of the cooling tower, and at the same time wastes a lot of waste heat. In addition, the steam jet vacuum pump unit uses working steam with a pressure of 1.0-1.5MPa.G, which not only increases the cost of equipment and valves, but also limits the application of centralized heating and the use of waste heat. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a steam jet vacuum pump unit that utilizes process waste heat and exhaust steam waste heat in response to the above-mentioned deficiencies in the prior art. The heat of the pressure-free waste steam is used to produce low-temperature water that cannot be stably supplied by the natural environment. The water is used as cooling water for the condenser, and has a stable and low water inlet temperature, thereby saving working steam and cooling water.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is a steam jet vacuum pump unit utilizing process waste heat and exhaust steam waste heat, comprising:

[0008] Hot water tank A warehouse is used to hold heat source water. Hot water tank B warehouse is used to hold sub-low temperature water.

[0009] The steam jet vacuum pump unit is multi-stage and connected in series from front to back. Each stage is composed of a condenser and a jet pump connected in series from front to back. Among them, the outlet of the last-stage jet pump is connected to the hot water tank A warehouse through a pipeline to introduce the waste steam into the heat source water in the hot water tank A warehouse.

[0010] The two ends of the absorption refrigeration machine's generator are respectively connected to the hot water tank A warehouse pipeline, using the heat source water as the heat source to form a heat source water circulation loop; the inlet and outlet ends of its evaporator are respectively connected to the hot water tank B warehouse and the hot water tank D warehouse pipeline to form a low-temperature water circulation channel, and after the low-temperature water is cooled inside, low-temperature water is obtained at the outlet end.

[0011] Furthermore, the temperature of the low-temperature water is 1-20°C.

[0012] Furthermore, each condenser is a direct condenser or an indirect condenser.

[0013] Furthermore, the low-temperature water outlet of the absorption refrigerator is connected to the front-end condenser pipeline, which is used to transport the low-temperature water pipeline to the front-end condenser spray device as low-temperature water for condensation.

[0014] Furthermore, the spraying devices of the other stages of condensers are all connected to the pipeline of the front-end condenser, so as to input the low-temperature cooling water after spraying in the front-end condenser into each spraying device.

[0015] Furthermore, the drain outlets of other stages of condensers are also connected to the hot water tank B warehouse pipeline for inputting the water after spraying into the hot water tank B warehouse.

[0016] Furthermore, a hot water tank D is provided on the connecting pipeline between the front-end condenser and the absorption refrigerator for containing low-temperature water.

[0017] Furthermore, two stages of jet pumps are connected in series in front of the frontmost condenser, and the front jet pump is connected to the vacuum tank through a pipeline, which is used for transmitting from front to back in the vacuum tank and discharged by the last stage jet pump;

[0018] Each jet pump is connected to a pipeline of a steam source supply device, and the steam source supply device is used to provide motive steam.

[0019] Furthermore, the hot water tank A warehouse, the hot water tank B warehouse, the hot water tank C warehouse and the hot water tank D warehouse are arranged in parallel in the same tank body, and the upper parts of the warehouses are connected.

[0020] Furthermore, in the steam jet vacuum pump unit, each condenser is independently placed horizontally; or, each condenser is stacked in sequence in the vertical direction, and the condenser on the top layer is the frontmost condenser.

[0021] The present invention has the following advantages: 1. The pressure-free waste steam discharged from the last-stage jet pump is used to heat the water in the hot water tank A, connected to the absorption refrigeration equipment to produce low-temperature water, and then sent to the No. 1 condenser as cooling water. The low-temperature water inlet advances the working point of the No. 1 condenser, which can save about 30% of steam and about 20% of cooling water. This not only reduces the load of the cooling tower, but also uses the heat of the waste steam to produce low-temperature water that cannot be stably supplied by the natural environment. 2. The low-temperature water produced by the process waste heat and exhaust steam waste heat has a stable and low water inlet temperature, saving working steam and cooling water. At the same time, it completely eliminates the adverse effects of the cooling water temperature exceeding 35°C caused by high temperature and high humidity in summer, ensuring the quality and output of the product. 3. The working point of the No. 1 condenser is advanced, and the compression ratio of the first-stage jet pump and the second-stage jet pump is greatly reduced, which provides good conditions for using low-pressure steam as working power; and creates conditions for using waste heat to produce low-pressure steam. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a steam jet vacuum pump unit utilizing process waste heat and exhaust steam waste heat according to the present invention;

[0023] Among them: 1. Vacuum tank; 2. First dust collector; 3. Second dust collector; 4. Main stop valve; 5. Steam source supply device; 6. First-stage jet pump; 7. Second-stage jet pump; 8. No. 1 condenser; 9. Third-stage jet pump; 10. No. 2 condenser; 11. Fourth-stage jet pump; 12. No. 3 condenser; 13. Fifth-stage jet pump; 14. Cooling tower; 15. Fifth water pump; 16. Absorption refrigeration equipment; 17. First water pump; 18. Hot water tank A warehouse; 19. Second water pump; 20. Third water pump; 21. Hot water tank B warehouse; 22. Hot water tank C warehouse; 23. Hot water tank D warehouse; 24. Fourth water pump. DETAILED DESCRIPTION

[0024] The present invention provides a steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat, such as Figure 1 As shown, it includes: a hot water tank A warehouse 18, which is used to contain heat source water; and a hot water tank B warehouse 21, which is used to contain sub-low temperature water.

[0025] The steam jet vacuum pump unit is multi-stage and connected in series from front to back. Each stage is composed of a condenser and a jet pump connected in series from front to back. Among them, the outlet of the last-stage jet pump is connected to the hot water tank A warehouse 18 through a pipeline, which is used to introduce steam into the heat source water in the hot water tank A warehouse 18.

[0026] The two ends of the generator of the absorption refrigeration machine 16 are respectively connected to the hot water tank A warehouse 18 pipeline, and the heat source water is used as the heat source to form a heat source water circulation loop; the inlet and outlet ends of the evaporator are respectively connected to the hot water tank B warehouse 21 pipeline to form a refrigerant circulation loop, and the refrigerant is cooled therein to obtain low-temperature water at the outlet end. The temperature of the low-temperature water is 1~20℃. The pressure-free waste steam discharged by the final stage jet pump is used to heat the water in the hot water tank A warehouse, connected to the absorption refrigeration equipment to produce low-temperature water, and then sent to the No. 1 condenser 8 as cooling water. The low-temperature water inlet advances the working point of the No. 1 condenser, which can save about 30% of steam and about 30% of cooling water. This not only reduces the load of the cooling tower, but also uses the heat of the waste steam to produce low-temperature water of constant temperature. In order to prevent the amount of steam discharged by the final stage jet pump from not meeting the heat required in the hot water tank A warehouse, another pipeline can be connected to the process waste heat source in the hot water tank A warehouse as a supplementary heat source.

[0027] The low-temperature water outlet of the absorption chiller 16 is connected to the frontmost condenser pipeline, which is used to transport the low-temperature water pipeline to the frontmost condenser spray device as spray water. A hot water tank D warehouse 21 is provided on the connecting pipeline between the frontmost condenser and the absorption chiller 16 for containing low-temperature water.

[0028] A two-stage jet pump is connected in series in front of the front-end condenser. The front-end jet pump is connected to the vacuum tank 1 through a pipeline to transfer the waste gas in the vacuum tank 1 from front to back and discharge it by the last-stage jet pump.

[0029] Each jet pump is connected to a steam source supply device 5 through a pipeline, and the steam source supply device 5 is used to provide motive steam.

[0030] Hot water tank A warehouse 18, hot water tank B warehouse 21, hot water tank C warehouse 23 and hot water tank D warehouse 23 are arranged in parallel in the same tank body, and the upper parts of each warehouse are connected. When the amount of water in a warehouse is large, it overflows from the upper part into other warehouses.

[0031] In the steam jet vacuum pump unit, each condenser is independently arranged horizontally and placed on a load-bearing platform. Alternatively, each condenser is stacked in sequence in the vertical direction, and the condenser on the top layer is the frontmost condenser.

[0032] One arrangement of the steam jet vacuum pump unit is as follows: the steam jet vacuum pump unit is a three-stage arrangement, and three condensers are independently arranged and each is placed horizontally on a load-bearing platform.

[0033] Another arrangement of the steam jet vacuum pump unit is as follows: the steam jet vacuum pump unit is a three-stage setting, and the three condensers are stacked in sequence in the vertical direction; the condensers themselves have a height, and when stacked, the lower condenser is equivalent to being placed at a certain height, and when the upper condenser is working, it can transport water and gas to the lower condenser under the action of gravity. There is no need to build a load-bearing platform to place each condenser, saving costs and space.

[0034] As an embodiment of the present invention, the steam jet vacuum pump unit is set up in three stages as an example; from front to back or from top to bottom, they are named as three-stage jet pump 9, four-stage jet pump 11 and five-stage jet pump 13, and the condensers connected in series in each stage are respectively No. 1 condenser 8, No. 2 condenser 10 and No. 3 condenser 12 from front to back or from top to bottom. Each condenser is a direct condenser or an indirect condenser.

[0035] An air inlet, an exhaust outlet, a water inlet and a drain outlet are provided.

[0036] When it is a direct condenser, the direct condenser is a vacuum container with an air inlet, an exhaust port, a water inlet and a drain port; a spray device is provided inside; the spray device is used to spray low-temperature water and is connected to the water inlet pipeline. The water inlet is generally opened at the top or middle of each condenser. The drain port is located at the bottom. There is no strict position requirement for the air inlet and the exhaust port. Generally, the air inlet is opened in the middle, and the air outlet is located at the top.

[0037] In an indirect condenser, the low-temperature water and the mixed gas do not come into direct contact. One of them is in the tube side and the other is in the shell side. In this embodiment, the route of the low-temperature water is the tube side, and the water inlet and the water outlet are both opened at the bottom of the condenser shell. The positions of the air inlet and the air outlet are determined by the design conditions.

[0038] Two stages of steam jet vacuum pumps are connected in series in front of the No. 1 condenser 8, namely the first stage jet pump 6 and the second stage jet pump 7, and the first stage jet pump 6 is connected to the vacuum tank 1 pipeline. The vacuum tank 1 is used to contain the objects to be processed. Each stage of the jet pump is connected to the steam source supply device 5 pipeline, and the steam source supply device 5 provides steam to each steam jet vacuum pump as power steam to carry the gas extracted from the vacuum tank 1 in the pipeline and reach the set pressure at the outlet of the second stage jet pump 7, matching the heat exchange with low-temperature water. The first dust collector 2 and the second dust collector 3 are connected in sequence between the vacuum tank 1 and the first stage jet pump 6, and a main stop valve 4 is provided on the outlet pipeline of the second dust collector 3. The impurities in the gas extracted from the vacuum tank 1 are filtered out after passing through the first dust collector 2 and the second dust collector 3.

[0039] In this embodiment, a hot water tank is provided, and in its cavity, it is horizontally divided into a hot water tank A warehouse 18, a hot water tank B warehouse 21, a hot water tank C warehouse 21 and a hot water tank D warehouse 23. The hot water tank A warehouse 18 contains heat source water, and the hot water tank B warehouse 21 contains refrigerant water. The upper spaces of the hot water tank A warehouse 18, the hot water tank B warehouse 21, the hot water tank C warehouse 21 and the hot water tank D warehouse 23 are not isolated, and each warehouse is connected. When there is too much water in one warehouse, it can flow to other warehouses. A buffer warehouse is set at the front end of the hot water tank A warehouse 18, so that when the exchange water after heat exchange flows in, it first flows into the buffer warehouse to play a buffering role. Since the temperature of the heat source water in the hot water tank A warehouse 18 is high, a vertical heat insulation board is also set between the hot water tank A warehouse 18 and the hot water tank B warehouse 21.

[0040] In this embodiment, the waste steam discharged from the end of the five-stage jet pump 13 is used as a heat source for the refrigerator 16. The steam outlet of the five-stage jet pump 13 is connected to an inlet pipeline of the hot water tank A warehouse 18 to discharge the steam at the end of the five-stage jet pump 13 into the heat source water, release heat in the heat source water, and the temperature of the heat source water rises to more than 85°C. The heated heat source water is used as the heat source of the absorption refrigeration equipment 16. Both ends of the generator of the absorption refrigeration equipment 16 are respectively connected to the pipeline of the hot water tank A warehouse 18 to form a heat source water circulation loop. After passing through the generator, the heat source water in the hot water tank A warehouse 18 first flows into the buffer warehouse, and then returns to the hot water tank A warehouse 18.

[0041] At the same time, the hot water tank B warehouse 21 is connected to the channel pipeline where the evaporator of the absorption refrigeration equipment 16 is located to form a low-temperature water circulation channel. After the sub-low-temperature water is cooled therein, low-temperature water of 1~20℃ is obtained at the outlet end.

[0042] A second water pump 19 is provided on the pipeline between the hot water tank B warehouse 21 and the absorption refrigeration equipment 16. A hot water tank D warehouse 21 is provided on the connecting pipeline between the No. 1 condenser 8 and the absorption refrigeration machine 16, which is used to hold low-temperature water. The outlet of the hot water tank D warehouse 23 is connected to the spray device pipeline of the No. 1 condenser 8, and a fourth water pump 24 is provided on the pipeline to transport the low-temperature water to the spray device of the No. 1 condenser 8 through the pipeline, and mix it with the power steam and the gas it carries to obtain the water after spraying. The non-condensable mixed gas after the first spraying is transported to the three-stage jet pump 9 through the pipeline, and after being pressurized, it is transported to the No. 2 condenser 10.

[0043] The drain outlet of the above-mentioned condenser No. 1 8 is connected to an inlet pipeline of the hot water tank C warehouse 21, and the outlet of the hot water tank C warehouse 21 is connected to the pipelines of the condensers No. 2 10 and No. 3 12. A third water pump 20 is arranged on the pipeline to transport the sprayed water to the spray devices of the condensers No. 2 10 and No. 3 12. In the condenser No. 2 10, the water is sprayed and mixed with the input power steam and the gas it carries to obtain sub-low temperature water. At the same time, the mixed gas after the second spraying is transported to the four-stage jet pump 11 through the pipeline, and after pressurization, it is transported to the condenser No. 3 12 through the pipeline, and mixed with the sub-cold water sprayed by the spray device of the condenser No. 3 12 to obtain re-cold water. At the same time, the mixed gas after the third spraying is transported to the condenser No. 3 12 through the pipeline. The drain outlets of the second condenser 10 and the third condenser 12 are connected to the inlet pipeline of the hot water tank B warehouse 21 to transport the re-cooled water to the hot water tank B warehouse 21, forming a water circulation loop and saving water.

[0044] The working process of a steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat in the present invention is as follows: the object to be processed, such as molten steel, is loaded into the vacuum tank 1. First, water is supplied to each condenser, and hot water is supplied to the refrigerator to produce low-temperature water. First, the five-stage jet pump 13 is turned on, and then the four-stage jet pump 11, the three-stage jet pump 9, the two-stage steam jet vacuum pump 7 and the one-stage steam jet vacuum pump 6 are turned on in sequence. At the same time, the steam in the steam source supply device 5 is transported to each steam jet vacuum pump 13, and the steam discharged from the five-stage jet pump 13 is discharged into the hot water tank A warehouse 18 through the outlet, so that the temperature of the heat source water in the hot water tank A warehouse 18 quickly reaches above 85 degrees. The heated heat source water is sent to the absorption refrigerator 16 by the first water pump 17, and returns to the hot water tank A warehouse 18 for circulation after cooling. The water in the hot water tank B warehouse 21 enters the refrigeration equipment, cools down to obtain low-temperature water of 1~20℃, and then is transported to the hot water tank D warehouse 23 through a pipeline. The waste gas is transported to the No. 1 condenser 8 by the fourth water pump 24, heated up after spraying, and discharged into the hot water tank B warehouse 21. It is then transported to the No. 2 condenser 10 and the No. 3 condenser 12 by the third water pump 20 for spraying and heat absorption, and discharged into the hot water tank B warehouse 19 after heating. The waste gas and impurities generated by the objects to be treated in the vacuum tank 1 are removed by the first dust collector 2 and the second dust collector 3, and the remaining waste gas is discharged into the hot water tank A warehouse through the main stop valve 4 and the various levels of jet pumps and condensers, so that the vacuum degree in the vacuum tank 1 reaches the process requirements. When stopping vacuuming, first turn off the first-level steam jet vacuum pump 6, then turn off the second-level steam jet vacuum pump 7, the third-level jet pump 9, the fourth-level jet pump 11 and the fifth-level jet pump 13 in turn, and turn off the steam source supply device 5.

Claims

1. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat, characterized in that: include: Hot water tank A compartment (18), which is used to hold heat source water; Hot water tank B compartment (21), which is used to contain sub-low temperature water; The steam jet vacuum pump unit is multi-stage and connected in series from front to back, and each stage is composed of a condenser and a jet pump connected in series from front to back; wherein the outlet of the last-stage jet pump is connected to the hot water tank A warehouse (18) through a pipeline, so as to guide the waste steam into the heat source water in the hot water tank A warehouse (18); The absorption refrigeration machine (16) has two ends of a generator connected to the pipeline of the hot water tank A bin (18) respectively, using the heat source water as the heat source to form a heat source water circulation loop; the inlet and outlet ends of the evaporator are connected to the pipelines of the hot water tank B bin (21) and the hot water tank D bin (23) respectively to form a low-temperature water circulation channel, and the low-temperature water is cooled therein to obtain low-temperature water at the outlet end; The low-temperature water outlet of the absorption refrigeration machine (16) is in communication with the frontmost condenser pipeline, and is used to transport the low-temperature water pipeline to the frontmost condenser spray device as low-temperature water for condensation.

2. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 1, characterized in that: The temperature of the low temperature water is 1-20°C.

3. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 1 or 2, characterized in that: Each of the condensers is a direct condenser or an indirect condenser.

4. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 3, characterized in that: The spraying devices of the other condensers at various stages are all connected to the pipeline of the front-end condenser, and are used to input the low-temperature cooling water after spraying in the front-end condenser into each of the spraying devices.

5. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 4, characterized in that: The drain outlets of the other condensers at each stage are also connected to the pipeline of the hot water tank B bin (21) for inputting the water after spraying into the hot water tank B bin (21).

6. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 5, characterized in that: A hot water tank D bin (23) is provided on the connecting pipeline between the frontmost condenser and the absorption refrigeration machine (16) for containing low-temperature water.

7. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 6, characterized in that: Two stages of jet pumps are connected in series in front of the frontmost condenser, the front jet pump being connected to the vacuum tank (1) via a pipeline and used for transmitting from front to back in the vacuum tank (1) and being discharged by the last stage jet pump; Each jet pump is connected to a pipeline of a steam source supply device (5), and the steam source supply device (5) is used to provide motive steam.

8. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 7, characterized in that: The hot water tank A warehouse (18), the hot water tank B warehouse (21), the hot water tank C warehouse and the hot water tank D warehouse (23) are arranged in parallel in the same tank body, and the upper parts of the warehouses are connected.

9. A steam jet vacuum pump unit utilizing process waste heat and exhaust waste heat according to claim 6, 7 or 8, characterized in that: In the steam jet vacuum pump unit, each condenser is independently placed horizontally; or, each condenser is stacked in sequence in the vertical direction, and the condenser on the top layer is the frontmost condenser.

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