A complete set of equipment for liquid pressurization and pressure potential energy recovery

Abstract

The present invention relates to a complete set of equipment for liquid pressurization and pressure potential energy recovery, including a reverse osmosis membrane group and a liquid pressurization device with pressure potential energy recovery, wherein the liquid pressurization device includes a concentrated water cylinder, a raw water cylinder and a hydraulic cylinder; the concentrated water cylinder is provided with a first piston and a first piston rod connected to the first piston, the raw water cylinder is provided with a second piston and a second piston rod connected to the second piston, the hydraulic cylinder is provided with a third piston and a third piston rod connected to the third piston, and the first piston rod, the second piston rod and the third piston rod are connected together. The present invention can be applied to water treatment projects such as membrane seawater desalination, urban garbage liquid treatment, and zero discharge of papermaking wastewater, and has the characteristics of high output pressure, high potential energy recovery efficiency, and high operating equipment utilization rate.

Description

Technical Field

[0001] The invention relates to a complete set of equipment for liquid pressurization and pressure potential energy recovery, belonging to the technical field of water treatment. Background Art

[0002] An important goal in the field of water treatment (including membrane desalination, municipal waste liquid treatment, zero discharge of papermaking wastewater, etc.) is to reduce operating costs. Energy consumption accounts for the largest proportion of operating costs, so reducing energy consumption is the most effective way to reduce water treatment operating costs.

[0003] Taking the application of membrane desalination engineering as an example, reverse osmosis desalination is one of the mainstream technologies for seawater desalination. That is, reverse osmosis membrane is used to separate ions and water molecules contained in seawater. At this time, the concentrated water discharged by the reverse osmosis membrane still contains extremely high pressure potential energy. If it is discharged directly, it will inevitably cause huge energy waste.

[0004] In order to reduce energy consumption and also reduce the production cost of seawater desalination, various forms of energy recovery devices have appeared since the 1970s. The earliest energy recovery device was a hydraulic turbine type. Its principle was to connect two impellers through a rotating shaft, all of which were encapsulated in a shell. When the concentrated water flows through the impeller, it impacts the blades and drives the impeller to rotate, thereby driving a turbine shaft to rotate. The turbine shaft directly drives the booster pump to work and output mechanical work. The high-pressure pump and the turbine booster pump are connected in series to increase the pressure of the original seawater, and the power consumption of the motor of the high-pressure pump is reduced by turbine boosting. However, since the energy of the concentrated water has to go through the two-step conversion of "water pressure energy-mechanical energy-water pressure energy", the mechanical energy loss is increased and the efficiency is low.

[0005] In the 1980s, an effective energy recovery technology emerged. Its working principle is "work exchange". Through the interface or separator, the pressure of high-pressure concentrated brine is directly transferred to the feed seawater. The process is simplified and only needs to go through the "water pressure energy-water pressure energy" one-step energy conversion, and the energy recovery efficiency can be improved. However, the energy recovery device using pressure exchange has a simple principle but a complex structure and manufacturing process, high manufacturing cost, and can not solve the problem of mixing concentrated water with raw water. Summary of the invention

[0006] The technical problem to be solved by the present invention is to propose a complete set of equipment for efficient liquid pressurization and pressure potential energy recovery, which can be applied to water treatment projects such as membrane seawater desalination, urban garbage liquid treatment, and zero discharge of papermaking wastewater to produce clean water at low cost.

[0007] The technical solution proposed by the present invention to solve the above technical problems is: a complete set of equipment for liquid pressurization and pressure potential energy recovery, including a reverse osmosis membrane group and a liquid pressurizing device with pressure potential energy recovery, the reverse osmosis membrane group has a raw water inlet, a concentrate water outlet and a clean water outlet; the liquid pressurizing device includes a concentrate water cylinder, a raw water cylinder and a hydraulic cylinder; a first piston and a first piston rod connected to the first piston are provided in the concentrate water cylinder, the first piston divides the concentrate water cylinder into two closed first concentrate water chambers and a second concentrate water chamber; a second piston and a second piston rod connected to the second piston are provided in the raw water cylinder, the second piston divides the raw water cylinder into two closed first raw water chambers and a second raw water chamber; a third piston and a third piston rod connected to the third piston are provided in the hydraulic cylinder, The third piston divides the hydraulic cylinder into two closed first hydraulic chambers and a second hydraulic chamber; the first piston rod, the second piston rod and the third piston rod are connected to each other; the liquid pressurizing device has a first working state in which the first raw water chamber is filled with water, the second raw water chamber is connected to the raw water inlet of the reverse osmosis membrane group, the first concentrated water chamber is connected to the concentrated water outlet of the reverse osmosis membrane group, the second concentrated water chamber is drained, the first hydraulic chamber is filled with oil, and the second hydraulic chamber is discharged with oil; and a second working state in which the first raw water chamber is connected to the raw water inlet of the reverse osmosis membrane group, the second raw water chamber is filled with water, the first concentrated water chamber is drained, the second concentrated water chamber is connected to the concentrated water outlet of the reverse osmosis membrane group, the first hydraulic chamber is discharged with oil, and the second hydraulic chamber is filled with oil; when in use, the liquid pressurizing device switches alternately between the first working state and the second working state.

[0008] The liquid pressurizing device in the present invention is used as the core equipment, and seawater, urban garbage liquid and papermaking wastewater are used as raw water, respectively. It can be applied to water treatment projects such as membrane seawater desalination, urban garbage liquid treatment, and zero discharge of papermaking wastewater. The beneficial effects brought by the present invention are as follows: 1) In the present invention, the concentrated water tank, raw water tank and hydraulic cylinder are independently arranged, so there is no hydraulic oil pollution of the water quality, and the mixing problem of concentrated water and raw water is avoided. 2) In the present invention, the raw water tank supplies high-pressure raw water to the reverse osmosis membrane group regardless of whether it is in the process or the return, and the process and return are both operated at full load to perform work. Similarly, the concentrated water tank and the hydraulic cylinder also perform work in the reciprocating process during operation, and the equipment operation utilization rate is nearly doubled.

[0009] The structural layout of the first piston rod, the second piston rod and the third piston rod in the liquid pressurizing device of the present invention can be arranged coaxially, or the first piston rod, the second piston rod and the third piston rod can be distributed in parallel with the central axis of the raw water cylinder, that is, the concentrated water cylinder, the raw water cylinder and the hydraulic cylinder are arranged parallel to each other, and the first piston rod, the second piston rod and the third piston rod are connected together by a connecting piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be further described below in conjunction with the accompanying drawings:

[0011] Figure 1 It is a structural diagram of embodiment 1 of the present invention.

[0012] Figure 2 This is an embodiment of the liquid pressurizing device in the second embodiment of the present invention.

[0013] Figure 3 This is another embodiment of the liquid pressurizing device in the second embodiment of the present invention.

[0014] Figure 4 It is a structural diagram of embodiment 3 of the present invention.

[0015] Figure numerals: oil tank 1, hydraulic pump 2, buffer 3, reverse osmosis membrane group 4, connecting part 5, concentrated water cylinder 10, first concentrated water chamber 11, second concentrated water chamber 12, first piston 13, first piston rod 14, raw water cylinder 20, first raw water chamber 21, second raw water chamber 22, second piston 23, second piston rod 24, hydraulic cylinder 30, first hydraulic chamber 31, second hydraulic chamber 32, third piston 33, third piston rod 34, first reversing valve 41, second reversing valve 42, third reversing valve 43. DETAILED DESCRIPTION

[0016] Embodiment 1

[0017] The complete set of equipment for liquid pressurization and pressure potential energy recovery in this embodiment is described by taking the application of membrane desalination engineering as an example, that is, using seawater as raw water. Figure 1 As shown, it includes a reverse osmosis membrane group 4 and a liquid pressurizing device with pressure potential energy recovery, wherein the reverse osmosis membrane group has a raw water inlet, a concentrated water outlet and a clean water outlet, and the liquid pressurizing device includes a concentrated water cylinder 10, a raw water cylinder 20 and a hydraulic cylinder 30.

[0018] A first piston 13 and a first piston rod 14 connected to the first piston 13 are disposed in the concentrated water cylinder 10 . The first piston 13 divides the concentrated water cylinder 10 into two closed first concentrated water chambers 11 and second concentrated water chambers 12 .

[0019] A second piston 23 and a second piston rod 24 connected to the second piston 23 are disposed in the raw water cylinder 20 . The second piston 23 divides the raw water cylinder 20 into two closed first raw water chambers 21 and second raw water chambers 22 .

[0020] A third piston 33 and a third piston rod 34 connected to the third piston 33 are disposed in the hydraulic cylinder 30 . The third piston 33 divides the hydraulic cylinder 30 into two closed first hydraulic chambers 31 and second hydraulic chambers 32 .

[0021] The first piston rod 14 , the second piston rod 24 and the third piston rod 24 are connected together.

[0022] The liquid pressurizing device in this embodiment has two working states, including water inflow to the first raw water chamber 21 (i.e., raw water enters the first raw water chamber 21), the second raw water chamber 22 is connected to the raw water inlet of the reverse osmosis membrane group 4 (i.e., the second raw water chamber 22 supplies high-pressure raw water to the reverse osmosis membrane group 4), the first concentrated water chamber 11 is connected to the concentrated water outlet of the reverse osmosis membrane group 4 (i.e., the high-pressure concentrated water discharged from the reverse osmosis membrane group 4 enters the first concentrated water chamber 11), the second concentrated water chamber 12 is drained (i.e., the high-pressure concentrated water is discharged from the second concentrated water chamber 12), the first hydraulic chamber 31 is filled with oil, and the second hydraulic chamber 3 ... 2, and the first working state in which the first raw water chamber 21 is connected to the water inlet of the reverse osmosis membrane group 4 (i.e., the first raw water chamber 21 supplies high-pressure raw water to the reverse osmosis membrane group 4), the second raw water chamber 22 is fed with water (i.e., the raw water enters the second raw water chamber 22), the first concentrated water chamber 11 is drained (i.e., the high-pressure concentrated water is discharged from the first concentrated water chamber 11), the second concentrated water chamber 12 is connected to the concentrated water outlet of the reverse osmosis membrane group 4 (i.e., the high-pressure concentrated water discharged from the reverse osmosis membrane group 4 enters the second concentrated water chamber 12), the first hydraulic chamber 31 is discharged with oil, and the second hydraulic chamber 32 is fed with oil. When in use, the liquid pressurizing device switches alternately between the first working state and the second working state.

[0023] When implementing, Figure 1 As shown, two working states of the liquid pressurizing device can be realized by controlling the states of the first reversing valve 41, the second reversing valve 42, and the third reversing valve 43, so that the low-pressure raw water that has entered the raw water cylinder is pressurized by the high-pressure concentrated water and the hydraulic cylinder, thereby realizing energy recovery and reducing energy consumption. That is, the first raw water chamber 21 and the second raw water chamber 22 are respectively connected to the raw water inlet of the reverse osmosis membrane group 4 through the third reversing valve 43, the first concentrated water chamber 11 and the second concentrated water chamber 12 are connected to the concentrated water outlet of the reverse osmosis membrane group 4 through the second reversing valve 42 or discharge concentrated water, and the first hydraulic chamber 31 and the second hydraulic chamber 32 are connected to the hydraulic pump 2 or the oil tank 1 through the first reversing valve 41.

[0024] When the equipment is just started, the hydraulic pump 2 generates a first pressure on the first piston rod, the second piston rod and the third piston rod and causes the first piston rod, the second piston rod and the third piston rod to move in a positive direction.

[0025] When the concentrate at the concentrate outlet of the reverse osmosis membrane group enters the first concentrate chamber or the second concentrate chamber, a second pressure is generated on the first piston rod, the second piston rod and the third piston rod. At the same time, the hydraulic pump 2 generates a third pressure on the first piston rod, the second piston rod and the third piston rod. The first piston rod, the second piston rod and the third piston rod move in the opposite direction under the action of the second pressure and the third pressure. The second pressure and the third pressure are in the same direction and the sum of the second pressure and the third pressure is equal to the first pressure.

[0026] Thereafter, the hydraulic pump 2 continuously generates a second pressure on the first piston rod, the second piston rod and the third piston rod, and at the same time, the concentrated water entering the first concentrated water chamber or the second concentrated water chamber continuously generates a third pressure on the first piston rod, the second piston rod and the third piston rod, and the first piston rod, the second piston rod and the third piston rod form a reciprocating movement under the combined force of the second pressure and the third pressure.

[0027] Since the second pressure and the third pressure are in the same direction and their sum is equal to the first pressure, the pressure output by the hydraulic pump in normal working state after startup is reduced while ensuring the pressure of the raw water inlet of the reverse osmosis membrane group (the first pressure), thereby greatly saving power and improving efficiency.

[0028] This embodiment can also be improved as follows: Figure 1 As shown, a buffer 3 is connected to the pipeline between the reverse osmosis membrane group 4 and the raw water tank 20, which is used to buffer the high-pressure raw water that is about to enter the reverse osmosis membrane group 4. The buffer 3 reduces the impact of the high-pressure raw water on the reverse osmosis membrane group 4, avoids damage to the reverse osmosis membrane group due to pressure shock, and ensures the service life of the reverse osmosis membrane group.

[0029] In this embodiment, the concentrate tank 10, the raw water tank 20 and the hydraulic cylinder 30 are independently arranged, so there will be no hydraulic oil pollution problem or mixing problem of concentrate and raw water. In addition, the reciprocating movement of the raw water tank 20 supplies high-pressure raw water to the reverse osmosis membrane group 4, and the equipment operation utilization rate is increased by nearly one-fold. Therefore, it has the characteristics of high output pressure, high potential energy recovery efficiency, and high operating equipment utilization rate.

[0030] This embodiment can adapt to different application scenarios according to different raw water. For example, if urban garbage liquid and papermaking wastewater are used as raw water, it can be applied to water treatment projects such as urban garbage liquid treatment and papermaking wastewater zero discharge.

[0031] Embodiment 2

[0032] This embodiment is proposed on the basis of the first embodiment, and is different from the first embodiment in that the concentrated water cylinder 10 , the raw water cylinder 20 and the hydraulic cylinder 30 are arranged in parallel with each other, and the first piston rod 14 , the second piston rod 24 and the third piston rod 24 are connected together by a connecting member 5 .

[0033] Preferably, Figure 2 and Figure 3 As shown, the liquid pressurizing device includes two concentrated water cylinders 10, a raw water cylinder 20 and two hydraulic cylinders 30. The connecting member 5 can be Figure 2 The straight-line connector shown in FIG. Figure 3 The disc-shaped connecting piece shown can of course also be a cross-shaped connecting piece.

[0034] Compared with the first embodiment, this embodiment can reduce the height of the liquid pressurizing device.

[0035] Embodiment 3

[0036] The liquid pressurizing device shown in Example 1 or Example 2 is only one group. This embodiment is further proposed on the basis of Example 1 or Example 2. The difference is that: according to the production demand or other technical requirements, multiple groups of liquid pressurizing devices with pressure potential energy recovery (such as Figure 4 There are two liquid pressurizing devices shown in FIG.

[0037] The present invention is not limited to the above embodiments, and any technical solutions formed by equivalent replacement shall fall within the protection scope required by the present invention.

Claims

1. A complete set of equipment for liquid pressurization and pressure potential energy recovery, comprising a reverse osmosis membrane group and a liquid pressurization device with pressure potential energy recovery, wherein the reverse osmosis membrane group has a raw water inlet, a concentrated water outlet and a clean water outlet; characterized in that: The liquid pressurizing device comprises a concentrated water cylinder, a raw water cylinder and a hydraulic cylinder; a first piston and a first piston rod connected to the first piston are provided in the concentrated water cylinder, the first piston divides the concentrated water cylinder into two closed first concentrated water chambers and a second concentrated water chamber; a second piston and a second piston rod connected to the second piston are provided in the raw water cylinder, the second piston divides the raw water cylinder into two closed first raw water chambers and a second raw water chamber; a third piston and a third piston rod connected to the third piston are provided in the hydraulic cylinder, the third piston divides the hydraulic cylinder into two closed first hydraulic chambers and a second hydraulic chamber; the first piston rod, the second piston rod and the third piston rod are connected to each other; The liquid pressurizing device has a first working state in which water flows into the first raw water chamber, the second raw water chamber is connected to the raw water inlet of the reverse osmosis membrane group, the first concentrated water chamber is connected to the concentrated water outlet of the reverse osmosis membrane group, the second concentrated water chamber is drained, the first hydraulic chamber flows into oil, and the second hydraulic chamber flows out oil; and a second working state in which the first raw water chamber is connected to the raw water inlet of the reverse osmosis membrane group, water flows into the second raw water chamber, the first concentrated water chamber is drained, the second concentrated water chamber is connected to the concentrated water outlet of the reverse osmosis membrane group, the first hydraulic chamber flows out oil, and the second hydraulic chamber flows into oil; when in use, the liquid pressurizing device switches alternately between the first working state and the second working state.

2. The complete set of equipment for liquid pressurization and pressure potential energy recovery according to claim 1, characterized in that: The concentrated water cylinder, the raw water cylinder and the hydraulic cylinder are arranged in parallel with each other, and the first piston rod, the second piston rod and the third piston rod are connected together through a connecting piece.

3. The complete set of equipment for liquid pressurization and pressure potential energy recovery according to claim 1, characterized in that: The first piston rod, the second piston rod and the third piston rod are coaxially arranged.

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