A condensate recovery device and control method thereof

Abstract

The present invention discloses a condensate recovery device and a control method thereof: comprising a condensate tank, the top interface of the condensate tank is respectively connected to a first circulating water cooler and a second circulating water cooler for condensate heat exchange through pipelines, the lower side end of the condensate tank is connected to a condensate pump inlet through a pipeline, and the condensate pump outlet is connected to a condensate pipe network through a pipeline. The present invention can reduce the temperature of the condensate and effectively prevent the occurrence of the "water hammer" phenomenon.

Description

Technical Field

[0001] The present invention relates to the field of chemical production, and more specifically, to a condensate recovery device and a control method thereof. Background Art

[0002] Since steam releases a large amount of latent heat when it changes from gas phase to liquid phase, steam is often used as a heating medium to heat materials to a specified temperature during chemical production. Traditional steam becomes condensate after heat exchange, and the condensate is directly incorporated into the condensate network. However, in large-scale chemical production processes, multiple streams of condensate with different pressure levels are often used, and the condensate has different temperatures. Some condensate contains a small amount of steam due to the steam trap. When it is incorporated into the condensate network, "water hammer" often occurs, which seriously endangers production safety. In order to avoid the "water hammer" phenomenon, it is often necessary to discharge this condensate, which is not only wasteful and has a poor on-site environment, but also increases the cost of sewage treatment and has high operating costs. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a condensate recovery device and a control method thereof, which can reduce the temperature of the condensate and effectively prevent the occurrence of the "water hammer" phenomenon.

[0004] The purpose of the present invention can be achieved through the following technical solutions.

[0005] The condensate recovery device of the present invention comprises a condensate tank, wherein the top interface of the condensate tank is respectively connected to a first circulating water cooler and a second circulating water cooler for condensate heat exchange through pipelines, the lower side end of the condensate tank is connected to a condensate pump inlet through a pipeline, and the condensate pump outlet is connected to a condensate pipe network through a pipeline.

[0006] The tube-side inlet of the first circulating water cooler is connected to the high-pressure condensate pipeline through a pipeline, the tube-side outlet of the first circulating water cooler is connected to the top interface of the condensate tank through a pipeline and extends below the liquid level in the condensate tank, the shell-side inlet of the first circulating water cooler is connected to the circulating water pipeline through a pipeline, and the shell-side outlet of the first circulating water cooler is connected to the circulating water return pipeline.

[0007] A first circulating water regulating valve is installed on the pipeline connected to the shell side inlet of the first circulating water cooler, and an online high-pressure condensate temperature meter is installed on the pipeline between the tube side outlet of the first circulating water cooler and the top interface of the condensate tank. The online high-pressure condensate temperature meter automatically controls the first circulating water regulating valve.

[0008] The tube side inlet of the second circulating water cooler is connected to the low-pressure condensate pipeline through a pipeline, the tube side outlet of the second circulating water cooler is connected to the top interface of the condensate tank through a pipeline and extends below the liquid level in the condensate tank, the shell side inlet of the second circulating water cooler is connected to the circulating water pipeline through a pipeline, and the shell side outlet of the second circulating water cooler is connected to the circulating water return pipeline.

[0009] A second circulating water regulating valve is installed on the pipeline connected to the shell side inlet of the second circulating water cooler, and an online low-pressure condensate temperature meter is installed on the pipeline between the tube side outlet of the second circulating water cooler and the top interface of the condensate tank. The online low-pressure condensate temperature meter automatically controls the second circulating water regulating valve.

[0010] A vent pipe is installed on the top of the condensate tank, and a condensate drain valve is installed on the lower side end of the condensate tank.

[0011] The condensate pump outlet pipeline is installed with a condensate level regulating valve and an online conductivity monitoring meter, and the side wall of the condensate tank is installed with an online level meter, which automatically controls the condensate level regulating valve.

[0012] A spare condensate pump is connected between the inlet and the outlet of the condensate pump via a pipeline.

[0013] The purpose of the present invention can also be achieved through the following technical solutions.

[0014] A control method for a condensate recovery device, characterized in that it includes the following processes:

[0015] The high-pressure condensate is merged into the high-pressure condensate pipeline, and the low-pressure condensate is merged into the low-pressure condensate pipeline;

[0016] The high-pressure condensate is heat-exchanged through the first circulating water cooler, and the condensate after heat exchange is monitored by an online high-pressure condensate temperature meter, and the circulating water flow is controlled by the first circulating water regulating valve to control the condensate temperature; similarly, the low-pressure condensate is heat-exchanged through the second circulating water cooler, and the condensate after heat exchange is monitored by an online low-pressure condensate temperature meter, and the circulating water flow is controlled by the second circulating water regulating valve to control the condensate temperature;

[0017] The condensate after heat exchange is discharged into the condensate tank. The condensate in the condensate tank is pressurized by the condensate pump and then merged into the condensate pipe network. The liquid level in the condensate tank is monitored by an online liquid level meter, and the liquid level in the condensate tank is automatically controlled by the condensate level regulating valve.

[0018] In addition, an online conductivity monitoring meter is used to monitor the water quality of the condensate. If the value of the online conductivity monitoring meter exceeds the standard, it proves that the water quality of the condensate exceeds the standard and needs to be repaired and put back into use after the cause is found.

[0019] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0020] (1) The present invention cools the condensate by a circulating water cooler, and at the same time, part of the steam in the condensate is completely condensed, thereby effectively preventing the occurrence of the "water hammer" phenomenon, ensuring production safety, and reducing sewage treatment costs.

[0021] (2) The present invention designs two condensate pipelines, high-pressure and low-pressure, to prevent the problem that the high-pressure and low-pressure condensate are simultaneously merged, resulting in the low-pressure condensate being unable to flow smoothly into the condensate tank, thereby ensuring stable production.

[0022] (3) The present invention automatically controls the circulation water circuit by adding a regulating valve through the condensate temperature meter after heat exchange, thereby ensuring the condensate temperature while reducing the use of circulating water and reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process flow of the condensate recovery device of the present invention.

[0024] Figure symbols: V1 condensate drain valve, TV1 first circulating water regulating valve, TV2 second circulating water regulating valve, LV1 condensate level regulating valve, S01 condensate tank, E01 first circulating water cooler, E02 second circulating water cooler, AI1 online conductivity monitoring meter, LIC1 online liquid level meter, TIC1 online high-pressure condensate temperature meter, TIC2 online low-pressure condensate temperature meter, P1 condensate pump. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] like Figure 1 As shown, the condensate recovery device of the present invention includes a condensate tank S01, and the top interface of the condensate tank S01 is connected to the first circulating water cooler E01 and the second circulating water cooler E02 for condensate heat exchange through pipelines. The lower side end of the condensate tank S01 is connected to the inlet of the condensate pump P1 through a pipeline, and the outlet of the condensate pump P1 is connected to the condensate pipe network through a pipeline.

[0027] The pipe side inlet of the first circulating water cooler E01 is connected to the high-pressure condensate pipeline through a pipeline, the pipe side outlet of the first circulating water cooler E01 is connected to the top interface of the condensate tank S01 through a pipeline and extends below the liquid level in the condensate tank S01, the shell side inlet of the first circulating water cooler E01 is connected to the circulating water pipeline through a pipeline, and the shell side outlet of the first circulating water cooler E01 is connected to the circulating water return pipeline. Among them, the first circulating water regulating valve TV1 is installed on the pipeline connected to the shell side inlet of the first circulating water cooler E01, and the online high-pressure condensate temperature meter TIC1 is installed on the pipeline between the pipe side outlet of the first circulating water cooler E01 and the top interface of the condensate tank S01, and the online high-pressure condensate temperature meter TIC1 automatically controls the first circulating water regulating valve TV1.

[0028] The tube side inlet of the second circulating water cooler E02 is connected to the low-pressure condensate pipeline through a pipeline, the tube side outlet of the second circulating water cooler E02 is connected to the top interface of the condensate tank S01 through a pipeline and extends below the liquid level in the condensate tank S01, the shell side inlet of the second circulating water cooler E02 is connected to the circulating water pipeline through a pipeline, and the shell side outlet of the second circulating water cooler E02 is connected to the circulating water return pipeline. Among them, the second circulating water regulating valve TV2 is installed on the pipeline connected to the shell side inlet of the second circulating water cooler E02, and an online low-pressure condensate temperature meter TIC2 is installed on the pipeline between the tube side outlet of the second circulating water cooler E02 and the top interface of the condensate tank S01, and the online low-pressure condensate temperature meter TIC2 automatically controls the second circulating water regulating valve TV2.

[0029] The condensate tank S01 is provided with a vent pipe at the top, and a condensate drain valve V1 is provided at the lower side of the condensate tank S01. The outlet pipeline of the condensate pump P1 is provided with a condensate level regulating valve LV1 and an online conductivity monitoring meter AI1, and the side wall of the condensate tank S01 is provided with an online level meter LIC1, which automatically controls the condensate level regulating valve LV1. A standby condensate pump is connected between the inlet and outlet of the condensate pump P1 through a pipeline, one for operation and one for standby.

[0030] The control method of the condensate recovery device of the present invention comprises the following process:

[0031] The steam condensate from each reboiler of the device is high-pressure condensate, which is incorporated into the high-pressure condensate pipeline. The steam seal condensate from the heating station and steam turbine of the device is low-pressure condensate, which is incorporated into the low-pressure condensate pipeline.

[0032] The high-pressure condensate is heat exchanged through the first circulating water cooler E01, and the condensate after heat exchange is monitored by the online high-pressure condensate temperature meter TIC1, and the circulating water flow is controlled by the first circulating water regulating valve TV1 to control the condensate temperature; similarly, the low-pressure condensate is heat exchanged through the second circulating water cooler E02, and the condensate after heat exchange is monitored by the online low-pressure condensate temperature meter TIC2, and the circulating water flow is controlled by the second circulating water regulating valve TV2 to control the condensate temperature.

[0033] The condensate after heat exchange is discharged into the condensate tank S01. The high-pressure condensate pipeline and the low-pressure condensate pipeline should extend below the liquid level of the condensate tank S01 to absorb the small amount of steam remaining in the two condensate pipelines, which can prevent the steam from being discharged into the atmosphere through the vent pipeline, thereby causing adverse effects on the surrounding environment. The condensate in the condensate tank S01 is pressurized by the condensate pump P1 and then merged into the condensate pipeline network. The liquid level in the condensate tank S01 is monitored by the online liquid level meter LIC1, and the liquid level in the condensate tank S01 is automatically controlled by the condensate level regulating valve LV1. An online conductivity monitoring meter AI1 is set at the outlet of the condensate pump P1 to monitor the water quality of the condensate. If the value of the online conductivity monitoring meter AI1 exceeds the standard, it proves that the water quality of the condensate exceeds the standard and needs to be repaired. After finding out the cause, it can be put back into use.

[0034] Implementation process and economic effect of the present invention:

[0035] The project was proposed at the end of 2011, and on-site investigation and design were carried out. Some new pipelines and condensate tanks, heat exchangers, condensate pumps and other equipment were added, and construction began in the second half of 2012. All of them were incorporated into the system in April 2013. After the steam condensate recovery project was put into operation, all steam condensate in the device area was recovered, and the on-site environment was greatly improved.

[0036] The condensate discharged on-site from synthetic ammonia and methanol acid degassing is calculated at 21 tons / hour and 18 tons / hour respectively, the condensate price is calculated at 7.08 yuan / ton, the electricity price is calculated at 0.583 yuan / kWh, the condensate pump power is calculated at 15KW, and the circulating water flow rate is calculated at 200m 3 / h, circulating water is 0.298 yuan / ton. The annual operation time is designed to be 8000 hours, and the annual benefit of recoverable condensate is:

[0037] (21+18)*8000*7.08-15*2*8000*0.583-200*2*8000*0.298=1.11544 million yuan / year.

[0038] Although the functions and working processes of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific functions and working processes. The above-mentioned specific implementation methods are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all within the protection of the present invention.

Claims

1. A condensate recovery device, characterized in that: It comprises a condensate tank (S01), wherein the top interface of the condensate tank (S01) is respectively connected to a first circulating water cooler (E01) and a second circulating water cooler (E02) for condensate heat exchange through pipelines, the lower side end of the condensate tank (S01) is connected to an inlet of a condensate pump (P1) through a pipeline, and the outlet of the condensate pump (P1) is connected to a condensate pipe network through a pipeline; The tube-side inlet of the first circulating water cooler (E01) is connected to the high-pressure condensate pipeline through a pipeline, the tube-side outlet of the first circulating water cooler (E01) is connected to the top interface of the condensate tank (S01) through a pipeline and extends below the liquid level in the condensate tank (S01), the shell-side inlet of the first circulating water cooler (E01) is connected to the circulating water pipeline through a pipeline, and the shell-side outlet of the first circulating water cooler (E01) is connected to the circulating water return pipeline; a first circulating water regulating valve (TV1) is installed on the pipeline connected to the shell-side inlet of the first circulating water cooler (E01), and an online high-pressure condensate temperature meter (TIC1) is installed on the pipeline between the tube-side outlet of the first circulating water cooler (E01) and the top interface of the condensate tank (S01), and the online high-pressure condensate temperature meter (TIC1) automatically controls the first circulating water regulating valve (TV1); The tube side inlet of the second circulating water cooler (E02) is connected to the low-pressure condensate pipeline through a pipeline, the tube side outlet of the second circulating water cooler (E02) is connected to the top interface of the condensate tank (S01) through a pipeline and extends below the liquid level in the condensate tank (S01), the shell side inlet of the second circulating water cooler (E02) is connected to the circulating water pipeline through a pipeline, and the shell side outlet of the second circulating water cooler (E02) is connected to the circulating water return pipeline.

2. The condensate recovery device according to claim 1, characterized in that: A second circulating water regulating valve (TV2) is installed on the pipeline connected to the shell side inlet of the second circulating water cooler (E02), and an online low-pressure condensate temperature meter (TIC2) is installed on the pipeline between the tube side outlet of the second circulating water cooler (E02) and the top interface of the condensate tank (S01). The online low-pressure condensate temperature meter (TIC2) automatically controls the second circulating water regulating valve (TV2).

3. The condensate recovery device according to claim 1, characterized in that: A vent pipe is installed at the top of the condensate tank (S01), and a condensate drain valve (V1) is installed at the lower side end of the condensate tank (S01).

4. The condensate recovery device according to claim 1, characterized in that: A condensate level regulating valve (LV1) and an online conductivity monitoring meter (AI1) are installed on the outlet pipeline of the condensate pump (P1), and an online level meter (LIC1) is installed on the side wall of the condensate tank (S01). The online level meter (LIC1) automatically controls the condensate level regulating valve (LV1).

5. The condensate recovery device according to claim 1, characterized in that: A spare condensate pump is connected between the inlet and outlet of the condensate pump (P1) via a pipeline.

6. A control method for a condensate recovery device according to any one of claims 1 to 5, characterized in that: The process includes: The high-pressure condensate is merged into the high-pressure condensate pipeline, and the low-pressure condensate is merged into the low-pressure condensate pipeline; The high-pressure condensate is heat exchanged through the first circulating water cooler (E01), and the condensate after heat exchange is monitored by the online high-pressure condensate temperature meter (TIC1), and the circulating water flow is controlled by the first circulating water regulating valve (TV1) to control the condensate temperature; similarly, the low-pressure condensate is heat exchanged through the second circulating water cooler (E02), and the condensate after heat exchange is monitored by the online low-pressure condensate temperature meter (TIC2), and the circulating water flow is controlled by the second circulating water regulating valve (TV2) to control the condensate temperature; The condensate after heat exchange is discharged into the condensate tank (S01). The condensate in the condensate tank (S01) is pressurized by the condensate pump (P1) and then merged into the condensate pipe network. The liquid level in the condensate tank (S01) is monitored by the online liquid level meter (LIC1), and the liquid level in the condensate tank is automatically controlled by the condensate level regulating valve (LV1). In addition, the online conductivity monitoring meter (AI1) is used to monitor the water quality of the condensate. If the value of the online conductivity monitoring meter (AI1) exceeds the standard, it proves that the water quality of the condensate exceeds the standard and needs to be repaired and put back into use after the cause is found.

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