Steam condensate recovery system and control method thereof

Abstract

This invention discloses a steam condensate recovery system and its control method. The recovery system includes: a water storage system for collecting steam condensate; a main heat exchange system connected to the water storage system for exchanging heat with the steam condensate flowing out of the water storage system; a water treatment system connected to the main heat exchange system for filtering the steam condensate flowing out of the main heat exchange system; and a secondary heat exchange system located between the water storage system and the main heat exchange system, wherein water flowing out of the water storage system can first flow through the secondary heat exchange system for heat exchange before flowing into the main heat exchange system for heat exchange. In this invention, the recovery system allows the secondary heat exchanger to perform initial heat exchange on the steam condensate, followed by secondary heat exchange on the steam condensate by the main heat exchanger. When the temperature of the steam condensate drops too slowly or too quickly due to high or low ambient temperatures, the recovery system can adjust accordingly to meet the temperature requirements of the water treatment device, allowing for uninterrupted operation.

Description

Technical Field

[0001] This invention relates to the field of steam condensate recovery technology, and more specifically, to a steam condensate recovery system and its control method. Background Technology

[0002] Industrial enterprises require large amounts of steam as a heat exchange and work medium during production, while also generating a significant amount of condensate. To save water costs, most enterprises adopt a method of recycling steam condensate for reuse. However, during the condensation and circulation process, the steam condensate inevitably becomes contaminated by pipelines, carrying impurities that have detached from the pipelines. Therefore, the steam condensate must be treated before it can be recycled.

[0003] Existing steam condensate recovery systems filter circulating steam condensate by connecting a water treatment unit with reverse osmosis equipment in series in the pipeline. However, this reverse osmosis equipment has strict requirements on the inlet water temperature, which cannot exceed 28°C.

[0004] The temperature of steam condensate is typically 90℃~100℃, and it cannot be directly introduced into water treatment equipment; it needs to be cooled first. Due to the high ambient temperature in summer, the steam condensate is difficult to cool to below 28℃ after only one cooling cycle through a heat exchanger. In current technology, from mid-June to mid-September each year, the steam condensate cannot be recovered and can only be discharged. In winter, due to the very low ambient temperature, the steam condensate temperature drops rapidly before entering the water treatment equipment, falling below 10℃. In this case, it needs to be heated to above 15℃ through a heat exchanger before being introduced into the water treatment system.

[0005] Due to the limitations imposed by ambient temperature on the steam recovery system, it cannot be used continuously, resulting in the idleness of the steam condensate recovery system.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a steam condensate recovery system to overcome the shortcomings of existing recovery systems that are limited by ambient temperature. Another purpose of this invention is to provide a method for controlling the steam condensate recovery system, so as to adjust the steps of the recovery system for processing steam condensate according to changes in ambient temperature, thereby ensuring that the recovery system can continuously process steam condensate.

[0008] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0009] A steam condensate recovery system includes: a water storage system for collecting steam condensate; a main heat exchange system connected to the water storage system for exchanging heat with the steam condensate flowing out of the water storage system; a water treatment system connected to the main heat exchange system for filtering the steam condensate flowing out of the main heat exchange system; and a secondary heat exchange system disposed between the water storage system and the main heat exchange system, wherein water flowing out of the water storage system can first flow through the secondary heat exchange system for heat exchange before flowing into the main heat exchange system for heat exchange.

[0010] Furthermore, it also includes: a first pipeline connecting the main heat exchange system and the water storage system; the secondary heat exchange system includes: a secondary heat exchanger and a second pipeline; the second pipeline is connected in parallel with the first pipeline and connects the main heat exchange system and the water storage system; the secondary heat exchanger is disposed on the second pipeline.

[0011] Furthermore, the second pipeline includes: a first section of pipeline connecting the water storage system and the auxiliary heat exchanger, and a second section of pipeline connecting the auxiliary heat exchanger and the main heat exchange system. Switch valves are respectively installed on the first section of pipeline and the second section of pipeline to control the on / off state of the first section of pipeline and the second section of pipeline.

[0012] Furthermore, the secondary heat exchange system also includes a third pipeline connecting the secondary heat exchanger and the water treatment system, wherein steam condensate in the water treatment system can flow into the secondary heat exchanger for heat exchange via the third pipeline.

[0013] Furthermore, the secondary heat exchange system also includes a deaerator and a fourth pipeline. The fourth pipeline connects the deaerator and the secondary heat exchanger. The steam condensate flowing out of the secondary heat exchanger can flow into the deaerator through the fourth pipeline to remove oxides from the steam condensate.

[0014] Furthermore, the main heat exchange system includes a transition water tank and a main heat exchanger connected in series. The transition water tank is connected to the water storage system, and the main heat exchanger is connected to the water treatment system. One end of the second pipeline is connected to the water storage system, and the other end is connected to the transition water tank.

[0015] Furthermore, the steam condensate recovery system includes a primary heat exchange program and a secondary heat exchange program. The primary heat exchange program involves controlling both the main heat exchange system and the secondary heat exchange system to be turned on for heat exchange. The secondary heat exchange program involves controlling one of the main heat exchange system and the secondary heat exchange system to be turned on for heat exchange.

[0016] Furthermore, a first temperature T1 and a second temperature T2 are preset, with T2 >> T1. The first-stage heat exchange program includes a first-stage heating program and a first-stage cooling program.

[0017] The ambient temperature T is obtained, and the obtained temperature T is compared with the preset first temperature T1. If T ≤ T1, the first-level heating program is executed; otherwise, the obtained temperature T is compared with the preset second temperature T2. If T ≥ T2, the first-level cooling program is executed.

[0018] Furthermore, the third temperature is preset to T1 < T3 < T2, and the secondary heat exchange program includes a secondary heating program and a secondary cooling program;

[0019] If the acquired temperature T1 < T < T2, then compare the acquired temperature T with the preset third temperature T3. If T < T3, then control the execution of the second-level heating program; if T > T3, then control the execution of the second-level cooling program.

[0020] Furthermore, it also includes a deoxygenation procedure, which includes: controlling the connection between the first section of pipeline and the fourth section of pipeline, and controlling the closure of the second section of pipeline.

[0021] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0022] 1. The steam condensate recovery system of this invention includes a main heat exchanger and an auxiliary heat exchanger. By controlling the opening and closing of the pipeline, the auxiliary heat exchanger and the main heat exchanger can be connected to the same recovery path, allowing the auxiliary heat exchanger to perform initial heat exchange on the steam condensate, and then the main heat exchanger to perform secondary heat exchange on the steam condensate. When the temperature of the steam condensate drops too slowly or too quickly due to high or low ambient temperatures, the recovery system is adjusted accordingly to meet the temperature requirements of the water treatment device, ensuring uninterrupted operation of the recovery system.

[0023] 2. It realizes the recycling of water resources and uses steam condensate as the water for equipment heat exchange, which reduces energy consumption. Using this system can simultaneously achieve the effective utilization of heat energy and water resources.

[0024] 3. By setting up a steam condensate recovery system, this invention enables the steam condensate recovery system to adapt to different ambient temperature conditions. By controlling the opening and closing status of the pipelines and the water source for heat exchange in the heat exchange loops of the main and auxiliary heat exchangers, the recovery system can be used in extremely cold or hot environments in winter or summer. It also realizes the recycling of water resources, reduces energy consumption, and effectively utilizes thermal energy and water resources.

[0025] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0026] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0027] Figure 1 This is a schematic diagram of a steam condensate recovery system according to the present invention;

[0028] Figure 2 This is a schematic diagram of a control method for a steam condensate recovery system according to the present invention;

[0029] Figure 3 This is a schematic diagram of another control method for a steam condensate recovery system according to the present invention.

[0030] The components are: 1. Condensate tank; 2. Transition water tank; 3. Main heat exchanger; 4. Water treatment device; 5. First section of pipeline; 6. Second section of pipeline; 7. Auxiliary heat exchanger; 8. Deaerator; 9. Third pipeline; 10. Fourth pipeline.

[0031] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0033] In the description of this invention, it should be noted that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "contact," and "communication" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] The main heat exchanger 3 and the auxiliary heat exchanger 7 in this invention each have two loops: a main loop and a heat exchange loop. The two loops are independent of each other, and the liquids flowing into the two loops only exchange heat.

[0036] Example 1

[0037] In this embodiment, as Figure 1 As shown, the steam condensate recovery system includes a condensate tank 1 for collecting steam condensate, i.e., a water storage system; a main heat exchanger 3 for exchanging heat with the steam condensate, i.e., a main heat exchange system; a water treatment device 4 for filtering the steam condensate flowing out of the main heat exchange system, i.e., a water treatment system; and an auxiliary heat exchanger 7, i.e., an auxiliary heat exchange system.

[0038] The auxiliary heat exchanger 7 is located between the condensate tank 1 and the main heat exchanger 3. The water flowing out of the condensate tank 1 first flows through the auxiliary heat exchanger 7 for heat exchange, then flows into the main heat exchanger 3 for heat exchange, and finally flows out of the water treatment device 4 for filtration. The above components are connected in sequence through pipelines.

[0039] Specifically, the steam condensate generated in industrial production first collects in condensate tank 1, then flows into auxiliary heat exchanger 7. Cooling water is circulated through the heat exchange loop of auxiliary heat exchanger 7 to exchange heat with the steam condensate. The condensate then flows into main heat exchanger 3, ensuring its temperature meets the requirements of the reverse osmosis equipment in the water treatment system. Finally, the heat-exchanged steam condensate flows into water treatment device 4, where impurities are filtered out to form demineralized water. This demineralized water can be recycled and reused in industrial production.

[0040] The steam condensate recovery system in this invention includes a main heat exchanger 3 and an auxiliary heat exchanger 7. The auxiliary heat exchanger 7 performs initial heat exchange on the steam condensate, and then the main heat exchanger 3 performs secondary heat exchange on the steam condensate. This prevents the recovery system from shutting down due to the steam condensate temperature dropping too slowly or too quickly when the ambient temperature is high or low, thus failing to meet the temperature requirements of the water treatment device.

[0041] Example 2

[0042] In this embodiment, the pipeline connecting the main heat exchanger 3 and the condensate tank 1 is the first pipeline. The secondary heat exchange system includes a secondary heat exchanger 7 and a second pipeline. The second pipeline is connected in parallel with the first pipeline, connecting the inlet of the secondary heat exchanger 7 to the condensate tank 1 and connecting the outlet of the secondary heat exchanger 7 to the main heat exchanger 3.

[0043] The second pipeline includes a first section 5 and a second section 6. Both sections are equipped with on / off valves, which can be used to control the flow path of steam condensate.

[0044] The first section of pipe 5 connects the inlet of the auxiliary heat exchanger 7 to the condensate tank, and the second section of pipe 6 connects the outlet of the auxiliary heat exchanger 7 to the main heat exchanger 3.

[0045] With this setup, the switching valve can be controlled manually or electrically, thereby controlling the connection status between the auxiliary heat exchanger 7 and the second pipeline. The inlet of the main circuit of the auxiliary heat exchanger 7 is connected to the outlet of the condensate tank 1 through the first section of pipeline 5, and the outlet of the main circuit of the auxiliary heat exchanger 7 is connected to the inlet of the main heat exchanger 3 through the second section of pipeline 6.

[0046] In this embodiment, in the steam condensate recovery system, by controlling the opening and closing states of the first section of pipeline 5 and the second section of pipeline 6, the main circuit of the auxiliary heat exchanger 7 is connected in parallel or in series with the condensate tank 1 and the main heat exchanger 3, thereby achieving the purpose of controlling the auxiliary heat exchanger 7 to be connected in series or in parallel with the first pipeline.

[0047] This allows the recovery system to adjust its treatment method for steam condensate based on changes in the environment.

[0048] Example 3

[0049] In this embodiment, as Figure 1 As shown, the auxiliary heat exchanger 7 has a main circuit and a heat exchange circuit. The water inlet of the heat exchange circuit of the auxiliary heat exchanger 7 is connected to the water outlet of the water treatment device 4 through the third pipe 9. This configuration allows the circulating water treated by the water treatment device 4 to be used directly to exchange heat with the high-temperature steam condensate. By using the treated circulating water for heat exchange, the consumption of new water resources can be reduced, and water resources can be avoided.

[0050] Example 4

[0051] As one embodiment of the present invention, such as Figure 1 As shown, the secondary heat exchange system also includes a deaerator 8 and a fourth pipeline 10. The fourth pipeline 10 connects the inlet of the deaerator 8 to the outlet of the secondary heat exchanger 7, which can treat the water flowing out of the secondary heat exchanger 7 to remove oxides, so as to meet the oxide content requirements of various equipment in industrial production.

[0052] In this system, water that has undergone heat exchange in the heat exchange circuit of the auxiliary heat exchanger 7 can also be directly fed into the deaerator 8.

[0053] Water treated by deaerator 8 can be used in equipment where there are restrictions on oxides in the water.

[0054] Based on the equipment's requirements for the oxide content in steam condensate, the recovery system can treat only the steam condensate to remove oxides, eliminating the step of filtering impurities by the water treatment device 4, saving water treatment steps, speeding up the processing, and reducing processing costs.

[0055] This setup allows for the classification and treatment of circulating water according to the diverse needs of industrial production, thereby improving water treatment efficiency and saving energy and resources.

[0056] Example 5

[0057] In another embodiment of the present invention, the steam condensate recovery system includes a transition water tank 2 and a main heat exchanger 3. The transition water tank 2 is connected in series between the condensate tank 1 and the main heat exchanger 3. The auxiliary heat exchanger 7 is connected to the condensate tank 1 and the transition water tank 2 through a second pipeline.

[0058] Depending on the heat exchange requirements, the outlet of the heat exchange circuit of the main heat exchanger 3 can also be connected to the transition water tank 2.

[0059] In this embodiment, the transition water tank 2 is used to collect the water after heat exchange in the main circuit of the auxiliary heat exchanger 7, the water directly introduced from the condensate tank 1, and the water discharged from the heat exchange circuit of the main heat exchanger 3. The transition water tank 2 collects water from multiple sources, and water of different temperatures is fully mixed in the transition water tank 2, which can ensure the stability of the temperature and flow rate of the water entering the main circuit of the main heat exchanger 3, and ensure that the water treatment device can continue to be in a healthy working state.

[0060] Example 6

[0061] This embodiment provides a method for controlling a steam condensate recovery system, including a primary heat exchange program and a secondary heat exchange program.

[0062] The primary heat exchange procedure is to control both the main heat exchanger 3 and the auxiliary heat exchanger 7 to be turned on for heat exchange; the secondary heat exchange procedure is to control either the main heat exchanger 3 or the auxiliary heat exchanger 7 to be turned on for heat exchange.

[0063] If the ambient temperature is high, the temperature of the steam condensate will decrease slowly as it flows through the pipeline. If the temperature requirement of the reverse osmosis equipment of the water treatment device cannot be met after one heat exchange treatment, the first-stage heat exchange program can be activated by controlling the opening and closing of the pipeline, so that the steam condensate can flow through the heat exchanger twice. The steam condensate recovery system can perform two cooling treatments on the steam condensate, so that the temperature of the water introduced into the water treatment device 4 does not exceed 28°C.

[0064] Specifically, before the steam condensate passes through the transition water tank 2, the steam condensate undergoes a first heat exchange with the auxiliary heat exchanger 7. After the heat exchange, the condensate is fully mixed with the condensate from the main heat exchanger 3 in the transition water tank 2. Then, the water in the transition water tank 2 is introduced into the main heat exchanger 3 for a second heat exchange, which meets the water temperature requirements of the water treatment device 4. The water is then filtered of impurities by the water treatment device 4 and recycled.

[0065] For example, in summer, due to the high ambient temperature, the steam condensate cools very slowly as it flows through the pipeline. Cooling by the main heat exchanger 3 alone is insufficient to meet the water temperature requirements of the water treatment unit 4. In this case, the control and recovery system performs a primary heat exchange procedure, requiring the auxiliary heat exchanger 7 to initially cool the steam condensate. After cooling, the condensate is mixed with the condensate from the heat exchange loop of the main heat exchanger 3 in the transition water tank 2, controlling the temperature of the steam condensate within a certain range. Then, the mixed water undergoes a secondary cooling process by the main heat exchanger 3, ultimately ensuring that the steam condensate entering the water treatment unit 4 meets the requirements of the reverse osmosis equipment before being introduced into the water treatment unit 4.

[0066] In this invention, by controlling the opening and closing of the steam condensate recovery system pipeline, the auxiliary heat exchanger and the main heat exchanger can be connected to the same recovery path. The auxiliary heat exchanger is used to cool the steam condensate once, and then the main heat exchanger cools it a second time. This allows the steam condensate to be cooled to below 28°C even when the ambient temperature is high, meeting the special temperature requirements of the water treatment device. After treatment by the water treatment device, it can be recycled, realizing that the steam condensate recovery system is not limited by the ambient temperature and can be used uninterruptedly throughout the year.

[0067] Example 7

[0068] In this embodiment, the control method enables the steam condensate recovery system to automatically adjust the pipeline of the recovery system according to the ambient temperature and implement the corresponding heat exchange program.

[0069] A first temperature T1 and a second temperature T2 are preset, with T2 >> T1. The first-stage heat exchange program includes a first-stage heating program and a first-stage cooling program.

[0070] Obtain the ambient temperature T. Compare the obtained temperature T with the first temperature T1. If T ≤ T1, then execute the first-level heating program; otherwise, compare the obtained temperature T with the preset second temperature T2. If T ≥ T2, then execute the first-level cooling program.

[0071] Specifically, such as Figure 2 As shown, the control method for the recycling system includes the following steps:

[0072] Enable the recycling system;

[0073] S1 presets a first temperature T1 and a second temperature T2, where T2 >> T1;

[0074] S2 obtains the ambient temperature T;

[0075] S31 compares the magnitude of temperature T with the first temperature T1;

[0076] S32 If T≤T1, then control to execute the first-level heating program;

[0077] S41 If T > T1, then compare the magnitude of temperature T with the second temperature T2;

[0078] S42 If T≥T2, then the first-level cooling program will be executed.

[0079] S5 If T < T2, then control the execution of the secondary heat exchange program.

[0080] For example, the first temperature is 0°C, the second temperature is 40°C, and the ambient temperature is 20°C. Using this control method, the steam condensate recovery system will execute a two-stage heat exchange process.

[0081] In this embodiment, by presetting two temperature values ​​and comparing the acquired ambient temperature with the preset temperature values, the temperature range for the first-stage heating and cooling programs of the recovery system is given, so that the recovery system can automatically adjust the heat exchange program according to the ambient temperature and adapt to the temperature conditions of different seasons.

[0082] This method controls the opening and closing status of the pipelines in the recovery system and the water source for heat exchange in the heat exchange loops of the main and auxiliary heat exchangers, ensuring that the recovery system can be used under different temperature conditions, such as extremely high and extremely low ambient temperatures in summer and winter. It also realizes the recycling of water resources, reduces energy consumption, and effectively utilizes thermal energy and water resources.

[0083] Example 8

[0084] In this embodiment, the secondary heat exchange program includes a secondary heating program and a secondary cooling program.

[0085] A third temperature T3 is preset, which is between the first and second temperatures, i.e., T1 < T3 < T2. If the acquired temperature T1 < T < T2, the acquired temperature T is compared with the third temperature T3. If T < T3, the second-level heating program is executed; if T > T3, the second-level cooling program is executed.

[0086] Specifically, such as Figure 3 As shown, the control method for the recycling system includes the following steps:

[0087] Enable the recycling system;

[0088] S1 presets a first temperature T1, a second temperature T2, T2>>T1, and a third temperature T3;

[0089] S2 obtains the ambient temperature T;

[0090] S31 compares the magnitude of temperature T with the first temperature T1;

[0091] S32 If T≤T1, then control to execute the first-level heating program;

[0092] S41 If T > T1, then compare the magnitude of temperature T with the second temperature T2;

[0093] S42 If T≥T2, then the first-level cooling program will be executed.

[0094] S51 If T < T2, then compare the obtained temperature T with the third temperature T3;

[0095] S52 If T < T3, then control the execution of the two-stage heating program;

[0096] If T≥T3, then the control will execute the secondary cooling program.

[0097] For example, the first temperature is 0°C, the second temperature is 40°C, the third temperature is 25°C, and the ambient temperature is 20°C. Using this control method, the steam condensate recovery system will execute a two-stage heating program.

[0098] In this embodiment, the external environmental conditions with temperature values ​​between the first temperature T1 and the second temperature T2 are further refined. By controlling a heat exchanger to raise or lower the temperature and setting the boundaries for raising and lowering the temperature, the control method controls the on / off of the pipelines of the recovery system, the flow path of the steam condensate and the heat exchange steps based on a more accurate temperature range, and more accurately controls the recovery system to recycle and reuse the steam condensate.

[0099] Example 9

[0100] In this embodiment, the control method includes a deoxygenation procedure: controlling the first section of pipeline 5 to be connected, controlling the second section of pipeline 6 to be closed, and controlling the fourth section of pipeline 10 to be connected. At this time, the steam condensate flows through the condensate tank 1, the auxiliary heat exchanger 7 and the deaerator 8 in sequence, which can exchange heat with the steam condensate and remove oxides from the water.

[0101] Specifically, steam condensate can enter the auxiliary heat exchanger 7 through pipelines for heat exchange, and after heat exchange, it is passed into the deaerator 8 for oxide removal. The treated water can meet the needs of certain equipment that only has restrictions on oxides, thereby reducing some unnecessary steps in the water treatment process, saving resources and improving the efficiency of the steam condensate recovery system.

[0102] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A steam condensate recovery system, characterized in that, include: A water storage system, specifically a condensate tank used to collect steam condensate; The main heat exchange system includes a transition water tank (2) and a main heat exchanger (3). The transition water tank (2) is connected in series between the main circuit of the water storage system and the main circuit of the main heat exchanger (3). The outlet of the heat exchange circuit of the main heat exchanger is connected to the transition water tank. The secondary heat exchange system includes a secondary heat exchanger (7), a first section of pipeline (5) connecting the water storage system and the secondary heat exchanger (7), and a second section of pipeline (6) connecting the secondary heat exchanger (7) and the transition water tank (2); the transition water tank is used to collect water after heat exchange in the main circuit of the secondary heat exchanger, water directly introduced from the condensate tank and water discharged from the heat exchange circuit of the main heat exchanger. The steam condensate recovery system includes: a primary heat exchange program that controls both the main heat exchanger and the auxiliary heat exchanger to be turned on for heat exchange; and a secondary heat exchange program that controls one of the main heat exchanger and the auxiliary heat exchanger to be turned on for heat exchange. When the first-stage heat exchange program is activated, the steam condensate undergoes a first heat exchange with the auxiliary heat exchanger before passing through the transition water tank. After the heat exchange, the condensate is mixed with the condensate in the heat exchange loop of the main heat exchanger in the transition water tank. Then, the water in the transition water tank is introduced into the main loop of the main heat exchanger for a second heat exchange, so that the temperature of the steam condensate meets the requirements of the reverse osmosis equipment. The water treatment system includes a reverse osmosis unit connected to the main heat exchange system for filtering steam condensate flowing out of the main heat exchange system; The control method for the recycling system includes the following steps: starting the recycling system; S1 presets a first temperature T1, a second temperature T2, T2>>T1, and a third temperature T3; S2 obtains the ambient temperature T; S31 compares the magnitude of temperature T with the first temperature T1; S32 If T≤T1, then control to execute the first-level heating program; S41 If T > T1, then compare the magnitude of temperature T with the second temperature T2; S42 If T≥T2, then the first-level cooling program will be executed. S51 If T < T2, then compare the obtained temperature T with the third temperature T3; S52 If T < T3, then control the execution of the two-stage heating program; If T≥T3, then the control will execute the secondary cooling program.

2. The steam condensate recovery system according to claim 1, characterized in that, Switch valves are installed on the first section of pipeline (5) and the second section of pipeline (6) respectively to control the opening and closing of the first section of pipeline (5) and the second section of pipeline (6).

3. The steam condensate recovery system according to claim 1, characterized in that, The secondary heat exchange system further includes a third pipeline (9), which connects the secondary heat exchanger (7) and the water treatment system. The inlet of the heat exchange circuit of the secondary heat exchanger is connected to the outlet of the water treatment device through the third pipeline. Water in the water treatment system can flow into the secondary heat exchanger (7) through the third pipeline (9) for heat exchange.

4. A steam condensate recovery system according to claim 3, characterized in that, The secondary heat exchange system also includes: a deaerator (8) and a fourth pipeline (10). The fourth pipeline (10) connects the deaerator (8) and the secondary heat exchanger (7). The steam condensate flowing out of the main circuit of the secondary heat exchanger (7) can flow into the deaerator (8) through the fourth pipeline (10) to remove oxides from the steam condensate. Water that has undergone heat exchange in the auxiliary heat exchanger circuit can also be directly fed into the deaerator.

5. A control method for a steam condensate recovery system as described in any one of claims 1-4, characterized in that: It also includes a deoxygenation process, which includes: controlling the connection of the first section pipeline (5) and the fourth pipeline (10), and controlling the closure of the second section pipeline (6); the steam condensate flows sequentially through the condensate tank, the auxiliary heat exchanger and the deaerator to exchange heat with the steam condensate and remove oxides from the water.

Images