Energy-saving open cycle cooling water system for hydrogen peroxide production line

Abstract

The utility model discloses a kind of hydrogen peroxide production line energy-saving open type circulating cooling water systems, cooling exchange equipment is located in the high position of hydrogen peroxide production line, the bottom of cooling tower is equipped with water collecting pool, upper portion is equipped with spray water distributor;The outlet of cooling tower water collecting pool is connected with the inlet of first cooling water circulating pump, the inlet and outlet of first cooling water circulating pump are equipped with first inlet valve and first outlet valve respectively;The outlet of first outlet valve is connected with the inlet of second cooling water circulating pump, the inlet and outlet of second cooling water circulating pump are equipped with second inlet valve and second outlet valve respectively;Second outlet valve outlet is connected with the cold side inlet of cooling exchange equipment through cooling water supply pipe, and the cold side outlet of cooling exchange equipment is connected with the spray water distributor inlet of cooling tower through cooling water return pipe;The outlet of first outlet valve is also connected with cooling water supply pipe through bypass valve. This system can save operating cost, reduce the energy consumption of system normal operation, ensure the stable operation of hydrogen peroxide production line.

Description

Technical Field

[0001] This utility model relates to a hydrogen peroxide production line, and more particularly to an energy-saving open-loop circulating cooling water system for a hydrogen peroxide production line, belonging to the field of high-efficiency and energy-saving industrial technology. Background Technology

[0002] Open-loop cooling water systems are a common industrial cooling method, primarily used for heat dissipation in process cooling exchange equipment. Cooling water in the cooling tower's collection tank (open and connected to the atmosphere) is pressurized by a cooling water circulation pump and sent to the cooling exchange equipment. There, it indirectly exchanges heat with the hot materials in the equipment. After absorbing heat, the cooling water's temperature rises. The heated cooling water flows to the upper part of the cooling tower and is evenly sprayed through a spray distributor. The spray liquid directly contacts the rising air inside the tower within the packing material, dissipating heat through the heat transfer system. The cooled water then falls back into the cooling tower's collection tank, forming a cycle.

[0003] In traditional hydrogen peroxide production plants, cooling towers and cooling water circulation pumps are typically located on the ground floor, while the cooling exchange equipment is mainly situated on the top floor, at a higher level within the hydrogen peroxide production unit. When selecting the head of the cooling water circulation pump, the greater of the following two factors should be considered: Case 1: Total resistance drop during normal operation: This is the sum of the water level difference H1 between the inlet of the spray water distributor and the liquid level in the cooling tower's water collection pool, the pressure drop of the cooling exchange equipment, the kinetic energy at the outlet of the cooling tower's spray water distributor, and the friction resistance of the entire pipeline system.

[0004] Scenario 2: The level difference that needs to be overcome during startup: namely, the level difference H2 between the cooling exchange equipment and the liquid level in the cooling tower's water collection pool.

[0005] When the value in Case 1 is less than the value in Case 2, that is, the total resistance during normal operation is reduced to the head of the cooling water circulation pump, it indicates that part of the head of the cooling water circulation pump is not effectively utilized, but is lost at the outlet of the spray water distributor. This results in energy loss, which is particularly noticeable in high-flow-rate cooling systems.

[0006] Excessive head of the cooling water circulation pump can lead to excessive system flow, increased operating power, and may even cause the pump to stop due to motor overcurrent, affecting the stable operation of the hydrogen peroxide production line. Utility Model Content

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0008] In view of the problems existing in the prior art, the present invention is proposed.

[0009] The purpose of this invention is to overcome the problems existing in the prior art and provide an energy-saving open-loop circulating cooling water system for hydrogen peroxide production lines. This system can make equipment selection more reasonable, save operating costs, reduce energy consumption during normal system operation, and ensure the stable operation of hydrogen peroxide production lines.

[0010] To solve the above technical problems, this utility model provides an energy-saving open-loop circulating cooling water system for a hydrogen peroxide production line, including a cooling exchange device and a cooling tower. The cooling exchange device is located at a high position in the hydrogen peroxide production line. The bottom of the cooling tower is equipped with a cooling tower water collection tank, and the upper part is equipped with a spray water distributor. The outlet of the cooling tower water collection tank is connected to the inlet of the first cooling water circulation pump through a cooling water outlet pipe. The inlet and outlet of the first cooling water circulation pump are respectively equipped with a first inlet valve and a first outlet valve. The outlet of the first outlet valve is connected to the inlet of the second cooling water circulation pump. The inlet and outlet of the second cooling water circulation pump are respectively equipped with a second inlet valve and a second outlet valve. The outlet of the second outlet valve is connected to the cold side inlet of the cooling exchange device through a cooling water supply pipe. The cold side outlet of the cooling exchange device is connected to the inlet of the spray water distributor of the cooling tower through a cooling water return pipe. The outlet of the first outlet valve is also connected to the cooling water supply pipe through a bypass pipe and the bypass valve.

[0011] Furthermore, the head of the first cooling water circulation pump is configured to overcome the total resistance during normal system operation. The total resistance includes the level difference H1 between the inlet of the spray water distributor and the liquid level in the cooling tower sump, the pressure drop of the cooling exchange equipment, the outlet kinetic energy of the cooling tower spray water distributor, and the sum of the friction resistance of the entire pipeline system.

[0012] Furthermore, when the first cooling water circulation pump and the second cooling water circulation pump are connected in series, the total head is greater than the level difference H2 between the cooling exchange equipment and the liquid level in the cooling tower collection pool that needs to be overcome when the system starts up.

[0013] Furthermore, the cooling tower, the first cooling water circulation pump, and the second cooling water circulation pump are all installed on the ground, and the inlets of the first cooling water circulation pump and the second cooling water circulation pump are both lower than the liquid level in the cooling tower's water collection tank.

[0014] Compared with the prior art, the advantages or beneficial effects of this utility model include at least the following: 1. When starting up, the two circulating pumps run simultaneously to overcome the level difference between the cooling exchange equipment and the liquid level in the cooling tower collection pool. After the system stabilizes, the second cooling water circulating pump is stopped, and only the first cooling water circulating pump is kept running normally. This way, while ensuring that the system does not vaporize at the highest point, the energy consumed during normal operation can be greatly saved.

[0015] 2. In the traditional scheme, the normal flow rate of a single cooling water circulation pump in a hydrogen peroxide plant is 2000 m³ / h, the head is 50 m, and the motor power is 400 kW. After adopting the scheme of this utility model, the parameters of the first cooling water circulation pump are: flow rate 2000 m³ / h, head 45 m, and motor power 355 kW; the parameters of the second cooling water circulation pump are: flow rate 2000 m³ / h, head 5 m, and motor power 55 kW. The comparison of benefits before and after adopting the utility model's technical scheme is as follows: Under normal operation, calculated based on the pump's rated power, with 8000 hours of operation per year, the annual cost savings are: (400-355) kW × 8000h = 360000 kW·h, 360000 kW·h × 0.6 yuan / kW·h = 216000 yuan, that is, an annual electricity cost saving of 216,000 yuan, which is quite significant. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein: Figure 1 This is a flowchart of the energy-saving open-loop circulating cooling water system for the hydrogen peroxide production line of this utility model; Reference numerals: Cooling exchange equipment E1; Cooling tower T; First cooling water circulation pump P1; Second cooling water circulation pump P2; First inlet valve V1; First outlet valve V2; Second inlet valve V3; Second outlet valve V4; Bypass valve V5; Cooling water outlet pipe G1; Cooling water supply pipe G2; Cooling water return pipe G3. Detailed Implementation

[0017] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0018] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0020] like Figure 1 As shown, the energy-saving open-loop circulating cooling water system for a hydrogen peroxide production line of this utility model includes a cooling exchange device E1, a cooling tower T, a first cooling water circulation pump P1, a second cooling water circulation pump P2, a first inlet valve V1, a first outlet valve V2, a second inlet valve V3, a second outlet valve V4, and a bypass valve V5. The cooling tower T, the first cooling water circulation pump P1, and the second cooling water circulation pump P2 are all installed on the ground, while the cooling exchange device E1 is located at a high position on the hydrogen peroxide production line.

[0021] The cooling tower T has an axial flow fan at the top center that draws air outwards, and air inlets are evenly distributed around the bottom outer perimeter of the cooling tower T. The inner cavity of the cooling tower T is filled with packing material to facilitate heat and humidity exchange between air and water. Above the packing material and at the upper part of the inner cavity of the cooling tower T, there are spray water distributors that distribute water downwards evenly. At the bottom of the cooling tower T, there is a cooling tower water collection pool for collecting the spray water.

[0022] The bottom outlet of the cooling tower's water collection pool is connected to the inlet of the first cooling water circulation pump P1 via a cooling water outlet pipe G1. A first inlet valve V1 is installed at the inlet of the first cooling water circulation pump P1, and a first outlet valve V2 is installed at the outlet of the first cooling water circulation pump P1. The outlet of the first outlet valve V2 is connected to the inlet of the second cooling water circulation pump P2. A second inlet valve V3 is installed at the inlet of the second cooling water circulation pump P2, and a second outlet valve V4 is installed at the outlet of the second cooling water circulation pump P2. The outlet of the second outlet valve V4 is connected to the cold side inlet of the cooling exchange equipment E1 via a cooling water supply pipe G2. The cold side outlet of the cooling exchange equipment E1 is connected to the inlet of the spray water distributor of the cooling tower T via a cooling water return pipe G3.

[0023] The outlet of the first outlet valve V2 is also connected to the cooling water supply pipe G2 via a bypass pipe and bypass valve V5.

[0024] The inlets of both the first cooling water circulation pump P1 and the second cooling water circulation pump P2 are lower than the liquid level in the cooling tower's water collection pool to ensure smooth startup of the circulation pumps and prevent air intake.

[0025] The head of the first cooling water circulation pump P1 is matched to overcome the total resistance of the system during normal operation, which is the difference in water level H1 between the inlet of the spray water distributor and the liquid level of the cooling tower collection pool + the pressure drop of the cooling exchange equipment E1 + the outlet kinetic energy of the cooling tower spray water distributor + the sum of the friction resistance of the entire pipeline system.

[0026] The total head of the first cooling water circulation pump P1 plus the second cooling water circulation pump P2 shall not be less than the additional supplementary pressure head that needs to be overcome when the cooling exchange equipment E1 and the liquid level of the cooling tower water collection pool during initial startup, i.e., the level difference H2 between the cooling exchange equipment E1 and the liquid level of the cooling tower water collection pool.

[0027] When the system is first started, in order to overcome the level difference H2 between the cooling exchange equipment E1 and the liquid level in the cooling tower collection pool, the first inlet valve V1, the first outlet valve V2, the second inlet valve V3 and the second outlet valve V4 are opened, the bypass valve V5 is closed, and the first cooling water circulation pump P1 and the second cooling water circulation pump P2 are connected in series.

[0028] After stable operation, open the bypass valve V5, close the second inlet valve V3 and the second outlet valve V4, and stop the second cooling water circulation pump P2, leaving only the first cooling water circulation pump P1 running. This satisfies both the high head requirement during startup and the total system resistance requirement after normal operation, significantly reducing system energy consumption while ensuring no vaporization at the highest point.

[0029] The above description is merely a preferred embodiment of the present utility model, showing and describing the basic principles, main features, and advantages of the present utility model. It is not intended to limit the scope of patent protection of the present utility model. Those skilled in the art should understand that the present utility model is not limited to the above embodiments. In addition to the above embodiments, the present utility model may have other implementations without departing from the spirit and scope of the present utility model. Various changes and improvements to the present utility model are also possible. All technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present utility model. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents. Technical features not described in the present utility model can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. An energy-saving open-loop circulating cooling water system for a hydrogen peroxide production line, comprising a cooling exchange device (E1) and a cooling tower (T), wherein the cooling exchange device (E1) is located at a high position in the hydrogen peroxide production line, and the cooling tower (T) has a cooling tower water collection tank at its bottom and a spray water distributor at its top, characterized in that: The outlet of the cooling tower water collection pool is connected to the inlet of the first cooling water circulation pump (P1) through the cooling water outlet pipe (G1). The inlet and outlet of the first cooling water circulation pump (P1) are respectively equipped with a first inlet valve (V1) and a first outlet valve (V2). The outlet of the first outlet valve (V2) is connected to the inlet of the second cooling water circulation pump (P2), and the inlet and outlet of the second cooling water circulation pump (P2) are respectively provided with a second inlet valve (V3) and a second outlet valve (V4); The outlet of the second outlet valve (V4) is connected to the cold side inlet of the cooling exchange equipment (E1) through the cooling water supply pipe (G2), and the cold side outlet of the cooling exchange equipment (E1) is connected to the spray water distributor inlet of the cooling tower (T) through the cooling water return pipe (G3). The outlet of the first outlet valve (V2) is also connected to the cooling water supply pipe (G2) via a bypass pipe and a bypass valve (V5).

2. The energy-saving open-loop circulating cooling water system for hydrogen peroxide production line according to claim 1, characterized in that: The head of the first cooling water circulation pump (P1) is configured to overcome the total resistance during normal system operation. The total resistance includes the level difference H1 between the inlet of the spray distributor and the liquid level in the cooling tower sump, the pressure drop of the cooling exchange equipment (E1), the outlet kinetic energy of the cooling tower spray distributor, and the sum of the friction resistance of the entire pipeline system.

3. The energy-saving open-loop circulating cooling water system for hydrogen peroxide production line according to claim 2, characterized in that: When the first cooling water circulation pump (P1) and the second cooling water circulation pump (P2) are connected in series, the total head is greater than the level difference H2 between the cooling exchange equipment (E1) and the liquid level in the cooling tower collection pool that needs to be overcome when the system starts up.

4. The energy-saving open-loop circulating cooling water system for a hydrogen peroxide production line according to claim 1, 2, or 3, characterized in that: The cooling tower (T), the first cooling water circulation pump (P1), and the second cooling water circulation pump (P2) are all installed on the ground, and the inlets of the first cooling water circulation pump (P1) and the second cooling water circulation pump (P2) are both lower than the liquid level of the cooling tower's water collection tank.

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