Cold and hot water separation energy-saving system of adsorption tower waterway system

Abstract

The utility model discloses a cold and hot water separation energy-saving system of an adsorption tower waterway system, relates to the technical field of polycrystalline silicon production, and aims to change a cold and hot water operation mode of the waterway system, reduce contact of cold and hot water and reduce steam consumption. According to the main technical scheme, the cold and hot water separation energy-saving system of the adsorption tower waterway system comprises an adsorption tower, a cold water part and a hot water part, the adsorption tower is provided with a coil pipe; the cold water part comprises a cold water tank, a cold water pump and a chilled water heat exchanger which are sequentially connected, the chilled water heat exchanger is connected with the lower end of the coil through a first pipeline, the first pipeline is provided with a first control valve, the cold water tank is connected with the upper end of the coil through a second pipeline, and the second pipeline is provided with a second control valve; the hot water part comprises a hot water tank, a hot water pump and a heater which are sequentially connected, the heater is connected with the lower end of the coil through a third pipeline, the third pipeline is provided with a third control valve, the hot water tank is connected with the upper end of the coil through a fourth pipeline, and the fourth pipeline is provided with a fourth control valve.

Description

Technical Field

[0001] The utility model relates to the technical field of polysilicon production, in particular to a cold and hot water separation energy-saving system for a water channel system of an adsorption tower. Background Art

[0002] In the production of polysilicon, an important process that enables the recycling of polysilicon production tail gas is the dry tail gas recovery system. The tail gas recovery process can recycle and reuse hydrogen, and can separate chlorosilane and hydrogen chloride in the tail gas. The main component of the tail gas is a large amount of hydrogen, which contains a small amount of chlorosilane and hydrogen chloride. The hydrogen (containing a small amount of HCl and chlorosilane) coming out of the top of the absorption tower is purified twice by an activated carbon adsorption tower to remove impurities in the hydrogen and is sent to the downstream workshop for use.

[0003] The saturated adsorption tower is heated by hot water through the water system, and the HCL and chlorosilane adsorbed on the adsorbent are completely resolved and purged out and enter the cooling absorption process. The cooling absorption process requires cutting off the hot water in the adsorption tower and passing cold water to cool it down. The excess hot water is driven to the steam condensation water tank and hot water system by cold water. The adsorption tower realizes absorption and regeneration through the alternating switching of cold and hot water.

[0004] In the regeneration state, the inner and outer coils of the adsorption tower need to be heated by hot water. In the cooling absorption state, the inner and outer coils need to be cooled by cold water. The inner and outer coils of the adsorption tower share a pipeline for hot and cold water. In the process of alternating hot and cold water, hot water enters the inlet of the cold water pump and cold water enters the inlet of the hot water pump. This process will increase steam consumption and waste more cooling capacity. Utility Model Content

[0005] In view of this, the utility model provides an adsorption tower water system cold and hot water separation energy-saving system, the main purpose of which is to change the cold and hot water operation mode of the water system, reduce the contact between cold and hot water, and reduce steam consumption.

[0006] In order to achieve the above purpose, the utility model mainly provides the following technical solutions:

[0007] The utility model provides an adsorption tower water system cold and hot water separation energy-saving system, the system comprises: an adsorption tower, a cold water part and a hot water part;

[0008] The adsorption tower is provided with a coil;

[0009] The cold water unit includes a cold water tank, a cold water pump and a chilled water heat exchanger connected in sequence, the chilled water heat exchanger and the lower end of the coil are connected through a first pipeline, the first pipeline is provided with a first control valve, the cold water tank and the upper end of the coil are connected through a second pipeline, the second pipeline is provided with a second control valve;

[0010] The hot water unit includes a hot water tank, a hot water pump and a heater connected in sequence, the heater and the lower end of the coil are connected through a third pipe, the third pipe is provided with a third control valve, the hot water tank and the upper end of the coil are connected through a fourth pipe, and the fourth pipe is provided with a fourth control valve.

[0011] The purpose of the utility model and the solution to its technical problems can also be further achieved by adopting the following technical measures.

[0012] Optionally, the position of the hot water tank and the position of the cold water tank are both higher than the position of the adsorption tower.

[0013] Optionally, a connecting pipe is further included, wherein both ends of the connecting pipe are respectively connected to the cold water tank and the hot water tank, and the connecting pipe is provided with a connecting valve.

[0014] Optionally, the first control valve, the second control valve, the third control valve, the fourth control valve, the hot water pump and the cold water pump are respectively integrated into a DCS control system.

[0015] Optionally, the connecting valve includes a first connecting valve and a second connecting valve, and the first connecting valve and the second connecting valve are sequentially installed in the connecting pipe.

[0016] Optionally, the chilled water heat exchanger and the heater are respectively shell and tube heat exchangers.

[0017] By means of the above technical solution, the utility model has at least the following advantages:

[0018] Three parallel adsorption towers form a group, in which, at the same time, one tower is adsorbing, one tower is regenerating, and one tower is cooling. This system uses one adsorption tower as the temperature adjustment object to illustrate the problem:

[0019] When the adsorbent in the adsorption tower is saturated with adsorption and needs to be regenerated, the first control valve and the second control valve are closed, the cold water pump is stopped synchronously, the third control valve and the fourth control valve are opened, the hot water pump is turned on, and the hot water in the hot water tank flows through the hot water pump and the heater in turn. After the hot water is further heated by the heater, it enters the inner and outer coils of the adsorption tower to achieve the purpose of raising the overall temperature of the adsorption tower, so that the hydrogen chloride and chlorosilane adsorbed on the adsorbent are thermally resolved;

[0020] When the adsorbent is heated and regenerated, the first control valve is opened, the cold water pump is started, and the third control valve is closed at the same time, the hot water pump is shut down, and the cold water pump delivers cold water into the coil, and the cold water drives the hot water out of the coil from bottom to top. After the driven hot water flows back to the hot water tank along the fourth pipeline, the fourth control valve is closed and the second control valve is opened at the same time, thereby realizing the complete switch from the adsorbent regeneration process to the adsorbent absorption process in the adsorption tower;

[0021] When the adsorbent needs to be regenerated again, open the third control valve, start the hot water pump, and at the same time close the first control valve and shut down the cold water pump. The hot water pump delivers hot water into the coil, and the hot water drives the cold water out of the coil from bottom to top. After the driven cold water flows back to the cold water tank along the second pipeline, close the second control valve and open the fourth control valve at the same time, thereby achieving a complete switch from the adsorbent absorption process in the adsorption tower to the adsorbent regeneration process.

[0022] By separating the cold and hot water pipelines, it is possible to prevent cold and hot water from entering the same condensate tank, thereby reducing the heat loss of hot water and the cooling loss of cold water, thus ensuring that the adsorption tower can quickly switch between the adsorbent regeneration state and the adsorbent absorption state. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A diagram of an energy-saving system for separating hot and cold water in an adsorption tower water system provided in an embodiment of the utility model.

[0024] The figure marks in the drawings of the specification include: adsorption tower 1, cold water tank 2, cold water pump 3, chilled water heat exchanger 4, first pipeline 5, first control valve 6, second pipeline 7, second control valve 8, hot water tank 9, hot water pump 10, heater 11, third pipeline 12, third control valve 13, fourth pipeline 14, fourth control valve 15, connecting pipe 16, first connecting valve 17, second connecting valve 18. DETAILED DESCRIPTION

[0025] In order to further explain the technical means and effects adopted by the utility model to achieve the predetermined utility model purpose, the specific implementation methods, structures, features and effects of the utility model application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0026] The utility model is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0027] An embodiment of the utility model provides an adsorption tower 1 water system cold and hot water separation energy-saving system, which comprises: an adsorption tower 1, a cold water part and a hot water part;

[0028] The adsorption tower 1 is provided with a coil;

[0029] The cold water part includes a cold water tank 2, a cold water pump 3 and a chilled water heat exchanger 4 connected in sequence, the chilled water heat exchanger 4 is connected to the lower end of the coil through a first pipe 5, the first pipe 5 is provided with a first control valve 6, the cold water tank 2 is connected to the upper end of the coil through a second pipe 7, the second pipe 7 is provided with a second control valve 8;

[0030] The hot water part includes a hot water tank 9, a hot water pump 10 and a heater 11 which are connected in sequence. The heater 11 is connected to the lower end of the coil through a third pipe 12. The third pipe 12 is provided with a third control valve 13. The hot water tank 9 is connected to the upper end of the coil through a fourth pipe 14. The fourth pipe 14 is provided with a fourth control valve 15.

[0031] The working process of the hot and cold water separation energy-saving system of the adsorption tower 1 water system is as follows:

[0032] When the adsorbent in the adsorption tower 1 is saturated with adsorption and needs to be regenerated, the first control valve 6 and the second control valve 8 are closed, the cold water pump 3 is stopped synchronously, the third control valve 13 and the fourth control valve 15 are opened, and the hot water pump 10 is turned on. The hot water in the hot water tank 9 flows through the hot water pump 10 and the heater 11 in sequence. After the hot water is further heated by the heater 11, it enters the inner and outer coils of the adsorption tower 1, so as to increase the overall temperature of the adsorption tower 1, so that the hydrogen chloride and chlorosilane adsorbed on the adsorbent are thermally resolved;

[0033] When the adsorbent is heated and regenerated, the first control valve 6 is opened, the cold water pump 3 is started, and the third control valve 13 is closed at the same time, and the hot water pump 10 is shut down. The cold water pump 3 delivers cold water into the coil, and the cold water drives the hot water out of the coil from bottom to top. After the driven hot water flows back to the hot water tank 9 along the fourth pipe 14, the fourth control valve 15 is closed, and the second control valve 8 is opened at the same time, thereby realizing the complete switch from the adsorbent regeneration process to the adsorbent absorption process in the adsorption tower 1;

[0034] When the adsorbent needs to be regenerated again, the third control valve 13 is opened, the hot water pump 10 is started, and the first control valve 6 is closed at the same time, and the cold water pump 3 is shut down. The hot water pump 10 delivers hot water into the coil, and the hot water drives the cold water out of the coil from bottom to top. After the driven cold water flows back to the cold water tank 2 along the second pipe 7, the second control valve 8 is closed and the fourth control valve 15 is opened at the same time, thereby realizing the complete switching of the adsorbent absorption process in the adsorption tower 1 to the adsorbent regeneration process.

[0035] In the technical solution of the utility model, by separating the cold and hot water pipelines, it is prevented that the cold and hot water enter the same condensation water tank, thereby reducing the heat loss of hot water and the cooling loss of cold water, thereby ensuring that the adsorption tower 1 can quickly switch between the adsorbent regeneration state and the adsorbent absorption state.

[0036] Specifically, a first hand valve is installed at the inlet of the cold water pump 3, and a second hand valve is installed at the outlet of the cold water pump 3; a third hand valve is installed at the inlet of the hot water pump 10, and a fourth hand valve is installed at the outlet of the hot water pump 10.

[0037] In a specific implementation, the position of the hot water tank 9 and the position of the cold water tank 2 are both higher than the position of the adsorption tower 1 .

[0038] In the present embodiment, specifically, the position of the hot water tank 9 and the position of the cold water tank 2 are both higher than the position of the adsorption tower 1; the hot water tank 9 is located at the highest point of the hot water equipment unit composed of the hot water tank 9, the hot water pump 10 and the heater 11, and the bubbles in the hot water rise and concentrate in the hot water tank 9, avoiding cavitation in the volute of the hot water pump 10; the cold water tank 2 is located at the highest point of the cold water equipment unit composed of the cold water tank 2, the cold water pump 3 and the chilled water heat exchanger 4, and the bubbles in the cold water rise and concentrate in the cold water tank 2, avoiding cavitation in the volute of the cold water pump 3.

[0039] In a specific embodiment, a connecting pipe 16 is further included, and two ends of the connecting pipe 16 are respectively connected to the cold water tank 2 and the hot water tank 9, and the connecting pipe 16 is provided with a connecting valve.

[0040] In this embodiment, specifically, the two ends of the connecting pipe 16 are respectively connected to the upper end of the cold water tank 2 and the upper end of the hot water tank 9. When the system is continuously running, the hot water in the hot water tank 9 circulates and evaporates due to heat. It is inevitable that the pressure in the hot water tank 9 is too high. At this time, the connecting valve can be opened, and the excessive gas pressure in the hot water tank 9 can be discharged into the cold water tank 2.

[0041] In a specific implementation, the first control valve 6 , the second control valve 8 , the third control valve 13 , the fourth control valve 15 , the hot water pump 10 and the cold water pump 3 are respectively integrated into a DCS control system.

[0042] In this embodiment, specifically, the operator can realize timely switching of the first control valve 6 and the third control valve 13, timely switching of the second control valve 8 and the fourth control valve 15, and timely switching of the hot water pump 10 and the cold water pump 3 through the DCS control system.

[0043] Specifically, according to the volume of the coil, the time taken for cold water to drive hot water out of the coil is the first time, and the time taken for hot water to drive cold water out of the coil is the second time. The first time is equal to the second time. The DCS control system processor stores level values ​​representing the first time and the second time, thereby determining the time interval for switching between the second control valve 8 and the fourth control valve 15.

[0044] Specifically, the first control valve 6, the second control valve 8, the third control valve 13 and the fourth control valve 15 are pneumatic valves, respectively, and the valve switches are driven by instrument air in the plant area where the system is located.

[0045] In a specific embodiment, the communication valve includes a first communication valve 17 and a second communication valve 18 , and the first communication valve 17 and the second communication valve 18 are sequentially installed in the communication pipe 16 .

[0046] In this embodiment, specifically, the first connecting valve 17 and the second connecting valve 18 are sequentially installed in the connecting pipe 16 to prevent a single connecting valve from leaking internally and causing uncontrolled cross-flow of cold and hot water in the connecting pipe 16 .

[0047] In a specific implementation, the chilled water heat exchanger 4 and the heater 11 are respectively shell and tube heat exchangers.

[0048] In this embodiment, specifically, both ends of the shell side of the chilled water heat exchanger 4 are respectively connected to the first pipe 5 and the outlet of the cold water pump 3, and the tube side of the chilled water heat exchanger 4 is connected to the 7°C water pipe; the shell side of the heater 11 is connected to the steam pipe, and both ends of the tube side of the heater 11 are respectively connected to the third pipe 12 and the outlet of the hot water pump 10.

[0049] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. An adsorption tower water system cold and hot water separation energy-saving system, characterized in that: include: An adsorption tower, wherein the adsorption tower is provided with a coil; A cold water unit, the cold water unit comprising a cold water tank, a cold water pump and a chilled water heat exchanger connected in sequence, the chilled water heat exchanger and the lower end of the coil are connected through a first pipe, the first pipe is provided with a first control valve, the cold water tank and the upper end of the coil are connected through a second pipe, the second pipe is provided with a second control valve; The hot water part includes a hot water tank, a hot water pump and a heater connected in sequence, the heater and the lower end of the coil are connected through a third pipe, the third pipe is provided with a third control valve, the hot water tank and the upper end of the coil are connected through a fourth pipe, and the fourth pipe is provided with a fourth control valve.

2. The adsorption tower water system cold and hot water separation energy-saving system according to claim 1, characterized in that: The position of the hot water tank and the position of the cold water tank are both higher than the position of the adsorption tower.

3. The adsorption tower water system cold and hot water separation energy-saving system according to claim 1 or 2, characterized in that: It also includes a connecting pipe, both ends of which are respectively connected to the cold water tank and the hot water tank, and the connecting pipe is provided with a connecting valve.

4. The adsorption tower water system cold and hot water separation energy-saving system according to claim 1 or 2, characterized in that: The first control valve, the second control valve, the third control valve, the fourth control valve, the hot water pump and the cold water pump are respectively integrated into a DCS control system.

5. The adsorption tower water system cold and hot water separation energy-saving system according to claim 3, characterized in that: The communication valve includes a first communication valve and a second communication valve, and the first communication valve and the second communication valve are sequentially installed on the communication pipe.

6. The adsorption tower water system cold and hot water separation energy-saving system according to claim 1 or 2, characterized in that: The chilled water heat exchanger and the heater are respectively shell and tube heat exchangers.

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