Energy-saving circulating water system

Abstract

The utility model discloses an energy-saving circulating water system which comprises a cooling tower, a cooling tower pool is arranged at the bottom of the cooling tower, the bottom of the cooling tower pool is connected with a water inlet of a circulating water pump, and a water outlet of the circulating water pump is respectively connected with a cold side inlet of a high pressure difference heat exchanger and a cold side inlet of a conventional heat exchanger. A cold side outlet of the conventional heat exchanger is connected with the top of the cooling tower through a circulating water system water return main pipe, a cold side outlet of the high-pressure-difference heat exchanger is connected with a non-pressure water return pool through a non-pressure water return main pipe, the non-pressure water return pool is connected with a hot water pump, and one path of a water outlet of the hot water pump is connected with the top of the cooling tower through a one-way valve. One path is connected with the cooling tower pool through a hot water regulating valve. According to the energy-saving circulating water system, the problems that the overall pressure of a circulating water pump is increased, the energy consumption is large, the number of newly-added booster pumps is increased and the energy consumption is low due to the fact that part of heat exchangers of a circulating water system of a chemical enterprise need large flow are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of circulating water systems, and in particular relates to an energy-saving circulating water system. Background Art

[0002] In the circulating water system of large chemical enterprises, the circulating water pressure difference of conventional heat exchangers is generally not high, but some heat exchangers or some devices often have high requirements for the outlet temperature on the material side, and need to increase the circulating water volume, that is, to ensure a certain pressure difference on the cold side of the heat exchanger to meet the process production needs. To achieve the above purpose, the conventional practice is to increase the pressure of the circulating water system, which causes a large increase in the overall energy consumption of the circulating water pump; another practice is to add a booster pump to each high-pressure differential heat exchanger for local boosting to ensure the normal operation of each high-pressure differential heat exchanger, but when the number of high-pressure differential heat exchangers is large, this practice is no longer suitable. On the one hand, if too many booster pumps are added, the additional energy consumption is also high, and economic operation cannot be achieved. On the other hand, due to the excessive number of booster pumps, the investment is large, and multiple new fault points will be added, causing inconvenience in management. Utility Model Content

[0003] The utility model aims to provide an energy-saving circulating water system to solve the problem that the flow rate required by some heat exchangers in the circulating water system of chemical enterprises is large, which will cause the overall pressure of the circulating water pump to increase, the energy consumption is relatively large, and the number and energy consumption of additional booster pumps will be increased.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: an energy-saving circulating water system, including a cooling tower, a cold water tower pool is arranged at the bottom of the cooling tower, the bottom of the cooling tower pool is connected to the water inlet of the circulating water pump, the water outlet of the circulating water pump is respectively connected to the cold side inlets of the high pressure difference heat exchanger and the conventional heat exchanger, the cold side outlet of the conventional heat exchanger is connected to the top of the cooling tower through the circulating water system return water mother pipe, the cold side outlet of the high pressure difference heat exchanger is connected to the pressureless return water pool through the pressureless return water mother pipe, the pressureless return water pool is connected to a hot water pump, and the water outlet of the hot water pump is connected to the top of the cooling tower through a one-way valve and connected to the cooling tower pool through a hot water regulating valve.

[0005] As a preferred technical solution of the utility model, a remote temperature meter is connected to the pipeline of the water outlet of the circulating water pump, and the remote temperature meter is used as a reference to adjust the opening of the hot water regulating valve.

[0006] As a preferred technical solution of the utility model, there are multiple circulating water pumps.

[0007] As a preferred technical solution of the present utility model, there are multiple cooling towers.

[0008] As a preferred technical solution of the utility model, a liquid level gauge is provided on the pressureless return water tank, and the liquid level gauge is used as a reference to adjust the rotation speed of the hot water pump.

[0009] The beneficial effects of the utility model are as follows: (1) The energy-saving circulating water system of the utility model solves the problem that the flow rate required by some heat exchangers in the circulating water system of chemical enterprises is large, which causes the overall pressure of the circulating water pump to increase and the energy consumption to be high; (2) The energy-saving circulating water system of the utility model can reduce the number of new booster pumps and energy consumption in the device area as much as possible. At the same time, it reduces the risk points of equipment failure and facilitates the operation and management of the system; (3) The energy-saving circulating water system of the utility model, by adding a pressure-free return water pipeline, connects the return water on the cold side of the high-pressure difference heat exchanger to the pressure-free return water mother pipe, thereby reducing the return water pressure on the cold side of the high-pressure difference heat exchanger, increasing the circulating water pressure difference, and increasing the circulating water volume, which can well ensure the production operation of this part of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of an energy-saving circulating water system of the utility model;

[0011] Figure 2 It is a structural schematic diagram of an anode plate in an energy-saving circulating water system of the utility model.

[0012] In the figure, 1. cooling tower pool, 2. circulating water pump, 3. remote temperature meter, 4. liquid level meter, 5. pressure-free return water pool, 6. high pressure difference heat exchanger, 7. conventional heat exchanger, 8. pressure-free return water main pipe, 9. circulating water system return water main pipe, 10. hot water pump, 11. hot water regulating valve, 12. check valve, 13. cooling tower. DETAILED DESCRIPTION

[0013] The technical solution of the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0014] Example 1

[0015] like Figure 1As shown, an energy-saving circulating water system of the utility model comprises a cooling tower 13, a cold water tower pool 1 is arranged at the bottom of the cooling tower 13, the bottom of the cooling tower pool 1 is connected to the water inlet of the circulating water pump 2, the water outlet of the circulating water pump 2 is respectively connected to the cold side inlets of the high pressure difference heat exchanger 6 and the conventional heat exchanger 7, the cold side outlet of the conventional heat exchanger 7 is connected to the top of the cooling tower 13 through the circulating water system return water mother pipe 9, the cold side outlet of the high pressure difference heat exchanger 6 is connected to the pressureless return water tank 5 through the pressureless return water mother pipe 8, the pressureless return water tank 5 is connected to a hot water pump 10, the outlet of the hot water pump 10 is connected to the top of the cooling tower 13 through a one-way valve 12, and is connected to the cooling tower pool 1 through a hot water regulating valve 11; a remote temperature meter 3 is connected between the hot water regulating valve 11 and the water outlet of the circulating water pump 2.

[0016] The utility model is an energy-saving circulating water system, and its specific working principle is:

[0017] In the circulating water system of large chemical enterprises, the pressure difference required for the circulating water of conventional heat exchangers 7 is generally not high, but some heat exchangers or some devices often have higher requirements for the outlet temperature on the material side, and it is necessary to increase the circulating water volume. At this time, a certain pressure difference on the cold side of the heat exchanger must be guaranteed to meet the process production requirements.

[0018] The return water of the circulating water system is generally led to the upper part of the cooling tower, distributed by the water distribution system, and then flows down in the tower, where it comes into countercurrent contact with the rising air to cool down, and is then recycled. The return water of the circulating water system needs to overcome the tower level difference and the pressure at the nozzle on the cooling tower, so the return water pressure is often relatively high. The return water pressure of the circulating water system of large chemical enterprises is generally between 0.20MPa and 0.25MPa.

[0019] Compared with the prior art, the energy-saving circulating water system of the utility model has the following two innovations:

[0020] (1) By adding a new non-pressure return water pipeline, the return water on the cold side of all heat exchangers with high pressure difference in the system is connected to the non-pressure return water main pipe 8. The non-pressure return water main pipe 8 connects all cooling water return water to the non-pressure return water tank 5. The return water pressure of the heat exchanger circulating water can be reduced to below 0.1 MPa, greatly improving the pressure difference of the heat exchanger circulating water.

[0021] (2) In order to ensure the liquid level of the pressureless return water tank 5, the hot water pump 10 adopts frequency conversion, and the liquid level is maintained within a certain range by adjusting the speed of the hot water pump 10. Specifically: the water outlet of the hot water pump 10 is divided into two branches. Under normal circumstances, when the system water supply temperature does not exceed the control temperature, the water outlet of the hot water pump 10 is directly discharged into the cooling tower pool 1 through the hot water regulating valve 11. Since this part is not cooled by the cooling tower, it will slightly increase the water supply temperature of the circulating water system to a certain extent. When the circulating water supply temperature rises in summer, the hot water regulating valve 11 automatically closes, and part or all of the circulating water enters the upper part of the cooling tower through the upper tower branch, and enters the cooling tower pool 1 after being cooled by the cooling tower, so as to ensure that the circulating water supply temperature is not affected by the pressureless return water system during the period of high temperature in summer. Since the hot water pump 10 only needs to transport the hot water of the pressureless return water tank 5 to the spray system or cooling tower pool 1 at the top of the cooling tower, the actual head is low, so the energy consumption of the hot water pump 10 is not high.

[0022] The utility model provides an energy-saving circulating water system, and the use method thereof comprises the following steps:

[0023] Step 1: The circulating water in the cooling tower pool 1 is pressurized by the circulating water pump 2 and then transported to the heat exchanger throughout the plant to cool down and exchange heat for process materials.

[0024] Step 2: After the circulating water of the conventional heat exchanger 7 completes the heat exchange task, it is uniformly transported to the upper part of the cooling tower through the system return water main pipe, and returns to the cooling tower pool 1 after being cooled and heat exchanged by the cooling tower.

[0025] Step 3: After the circulating water of the high pressure difference heat exchanger 6 completes the heat exchange task, it is uniformly transported to the non-pressure return water tank 5 through the non-pressure return water main pipe 8.

[0026] In step 4, the hot water pump 10 pressurizes the hot water in the pressure-free return water tank 5. The hot water pump 10 adjusts the water output by frequency conversion to ensure that the liquid level in the pressure-free return water tank is stable within a certain range.

[0027] Step 5: When the system water supply temperature does not exceed the control temperature, the water output from the hot water pump 10 is directly discharged into the cooling tower pool 1 through the hot water regulating valve 11.

[0028] Step 6, when the circulating water supply temperature rises in summer, the hot water regulating valve 11 is automatically closed, and part or all of the circulating water enters the upper part of the cooling tower through the upper tower branch, and enters the cooling tower pool 1 after being cooled by the cooling tower.

[0029] The purpose of the utility model is to provide an energy-saving circulating water system and control method, which can not only solve the problem that the flow rate required by some heat exchangers in the circulating water system of chemical enterprises is large, resulting in an increase in the overall pressure of the circulating water pump 2 and high energy consumption, but also reduce the number of new booster pumps and energy consumption in the device area as much as possible. By adding a new pressure-free return water pipeline, the return water on the cold side of the high-pressure difference heat exchanger 6 is uniformly connected to the pressure-free return water mother pipe 8, so as to reduce the return water pressure on the cold side of the high-pressure difference heat exchanger 6, increase the circulating water pressure difference of the heat exchanger, increase the circulating water volume, and ensure the production operation of this part of the heat exchanger.

[0030] Example 2

[0031] like Figure 1 As shown, different from Example 1, in Example 2, the energy-saving circulating water system of the utility model has a plurality of circulating water pumps 2 and a plurality of cooling towers 13.

[0032] A plurality of circulating water pumps 2, a plurality of hot water pumps 10 and a plurality of cooling towers 13 are provided, which can serve as backup for each other to prevent the system from being unable to operate normally when a single device fails.

[0033] Example 3

[0034] like Figure 1 As shown, different from Example 2, in Example 3, a liquid level meter 4 is provided on the pressureless return water tank 5 of the energy-saving circulating water system of the utility model, so as to observe the storage condition of the water in the pressureless return water tank 5 in real time and control the use status of the system.

Claims

1. Energy-saving circulating water system, characterized in that: The invention comprises a cooling tower (13), wherein a cooling tower pool (1) is arranged at the bottom of the cooling tower (13), the bottom of the cooling tower pool (1) is connected to the water inlet of a circulating water pump (2), the water outlet of the circulating water pump (2) is respectively connected to the cold side inlets of a high pressure difference heat exchanger (6) and a conventional heat exchanger (7), the cold side outlet of the conventional heat exchanger (7) is connected to the top of the cooling tower (13) through a circulating water system return water main pipe (9), the cold side outlet of the high pressure difference heat exchanger (6) is connected to a pressureless return water pool (5) through a pressureless return water main pipe (8), the pressureless return water pool (5) is connected to a hot water pump (10), the water outlet of the hot water pump (10) is connected to the top of the cooling tower (13) through a one-way valve (12), and is connected to the cooling tower pool (1) through a hot water regulating valve (11) at the other end.

2. The energy-saving circulating water system according to claim 1, characterized in that: A remote temperature meter (3) is connected to the pipe at the water outlet of the circulating water pump (2), and the remote temperature meter (3) is used as a reference to adjust the opening of the hot water regulating valve (11).

3. The energy-saving circulating water system according to claim 2 is characterized in that: The number of circulating water pumps (2) is multiple.

4. The energy-saving circulating water system according to claim 3 is characterized in that: The number of the cooling towers (13) is multiple.

5. The energy-saving circulating water system according to claim 4, characterized in that: The pressure-free return water tank (5) is provided with a liquid level meter (4), and the liquid level meter (4) is used as a reference to adjust the rotation speed of the hot water pump (10).

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