Constant temperature hot water control system for preheating with condensate water

Abstract

This invention discloses a control system for preheating constant-temperature hot water for tobacco stem washing using condensate. The main design concept of this invention is to utilize the waste heat of condensate in the workshop's condensate recovery main pipeline to provide heating energy for the water used in the tobacco stem washing machine during the water pretreatment process. Specifically, the recovered water in the workshop's steam condensate recovery main pipeline is used as a heat source to replace the original steam heating constant-temperature hot water. In practice, an adjustable flow valve is added to the condensate recovery main pipeline, and three-way branch pipes are installed at both ends of the flow valve. A water-immersed heating coil is installed at the end of one branch pipe, while the other branch pipe is used for user heat exchange return water. Thus, by utilizing the pressure difference formed by the condensate recovery pipeline itself at both ends of the flow valve, the flow rate of condensate flowing into the coil can be dynamically controlled by simply controlling the opening of the main flow valve, thereby achieving heat exchange circulation and controlling the heating speed and temperature of the hot water for washing tobacco stems.

Description

Technical Field

[0001] This invention relates to the field of cigarette manufacturing, and in particular to a constant temperature hot water control system for preheating and heating the stems using condensate. Background Technology

[0002] In the process of cleaning tobacco stems in cigarette manufacturing enterprises, reducing the steam consumption for heating hot water and improving energy efficiency is one of the main directions for exploration and technological improvement by tobacco companies in response to the call for energy conservation and emission reduction. Summary of the Invention

[0003] In view of the above, the present invention aims to provide a constant temperature hot water control system for washing stems by preheating condensate water, so as to solve the aforementioned technical problems.

[0004] The technical solution adopted in this invention is as follows:

[0005] This invention provides a control system for preheating and heating constant temperature hot water for washing stems using condensate, comprising: a first temperature sensor, a first pressure sensor, a first reducing tee, a flow control valve, a second pressure sensor, and a second reducing tee, which are sequentially installed on the main condensate recovery pipeline in the workshop according to the water flow direction;

[0006] The first reducing tee is also connected to a heated condensate pipe flowing to the heating coil, and a first electric shut-off valve is connected to the heated condensate pipe.

[0007] The second reducing tee is also connected to a return water pipe that receives condensate water returning from the constant temperature water tank, and a second electric shut-off valve is connected to the return water pipe.

[0008] Based at least on the water temperature and pressure of the workshop condensate recovery main pipeline, as well as the measured water temperature and water temperature set value of the constant temperature water tank, the opening degree of the flow control valve and the opening and closing of the two electric shut-off valves are controlled so that the condensate in the workshop condensate recovery main pipeline flows into the heated condensate pipe due to the pressure difference across the flow control valve, and after completing heat exchange in the constant temperature water tank, it flows back to the workshop condensate recovery main pipeline from the return water pipe.

[0009] In at least one possible implementation, the method by which the control system heats the washing stems with constant-temperature hot water specifically includes:

[0010] When the difference between the water temperature of the workshop condensate recovery main pipeline and the measured water temperature of the water tank, as well as the water pressure before the flow control valve, all meet the predetermined standards, and the measured water temperature of the water tank is less than the set water temperature value, the opening of the flow control valve is gradually reduced, and two electric shut-off valves are opened, while monitoring the pressure difference across the flow control valve during the process.

[0011] By adjusting the opening of the flow control valve, the pressure difference is maintained within a preset range.

[0012] When the measured water temperature in the water tank is detected to be close to the set water temperature value, the flow rate in the heated condensate pipe is reduced by adjusting the opening of the flow control valve.

[0013] Until the measured water temperature in the water tank reaches or exceeds the set water temperature value, the flow control valve is fully opened and the two electric shut-off valves are closed.

[0014] In at least one possible implementation, the method by which the control system heats the washing stems with constant-temperature hot water further includes:

[0015] When the difference between the water temperature in the workshop condensate recovery main pipeline and the measured water temperature in the water tank, or when the water pressure before the flow control valve does not meet the predetermined standard, the flow control valve shall be kept fully open and the two electric shut-off valves shall be kept closed.

[0016] In at least one of the possible implementations, a first flow meter is also provided on the main pipeline for workshop condensate recovery before the first reducing tee, based on the direction of water flow; and a second flow meter is provided on the heated condensate pipe.

[0017] In at least one of the possible implementations, both the first flow meter and the first flow transducer are electromagnetic flow transmitters.

[0018] In at least one of the possible implementations, a second temperature sensor is also connected to the return water pipe.

[0019] In at least one of the possible implementations, the heating coil is made of stainless steel and is installed in the original constant temperature water tank in an immersion manner.

[0020] Compared with the prior art, the main design concept of this invention is to utilize the waste heat of condensate in the workshop condensate recovery main pipeline to provide heating energy for the cleaning water of the tobacco stem washing machine during the water pretreatment process. Specifically, the recovered water in the workshop steam condensate recovery main pipeline is used as a heat source to replace the original steam heating constant temperature hot water. In specific implementation, an adjustable flow valve is added to the condensate recovery main pipeline, and three-way branch pipes are installed at both ends of the flow valve. A water-immersed heating coil is installed at the end of one branch pipe, while the other branch pipe is used for user heat exchange return water. Thus, by utilizing the pressure difference formed by the condensate recovery pipeline itself at both ends of the flow valve, the flow rate of condensate flowing into the coil can be dynamically controlled by only controlling the opening of the main flow valve, and heat exchange circulation can be achieved, thereby controlling the heating speed and temperature of the hot water for washing the stems.

[0021] Furthermore, this invention does not replace the original steam heating mode, but provides another hot water heating mode through the above-mentioned control and recovery of condensate. If the condensate flow rate, temperature difference, etc. cannot meet the heating requirements of hot water for washing stems, it is possible to ensure a continuous supply of hot water in the production process by supplementing steam heating. Attached Figure Description

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of a constant temperature hot water control system for washing stems using condensate preheating, provided in an embodiment of the present invention. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] This invention proposes an embodiment of a constant-temperature hot water control system for washing stems using condensate preheating. Specifically, as follows: Figure 1 As shown, it includes: a first flow meter 2 (V1 mentioned below, which may be an electromagnetic flow transmitter), a first temperature sensor 3 (T1 mentioned below), a first pressure sensor 4 (P1 mentioned below), a first reducing tee 10, a flow control valve 1, a second pressure sensor 9 (P2 mentioned below), and a second reducing tee 20, which are installed sequentially on the main condensate recovery pipeline 100 of the workshop based on the water flow direction.

[0026] The first reducing tee 10 is also connected to a heated condensate pipe 200 that flows to the heating coil. A first electric shut-off valve 5 and a second flow meter 6 (V2 mentioned below, which can be an electromagnetic flow transmitter) are connected sequentially on the heated condensate pipe 200 according to the water flow direction.

[0027] The second reducing tee 20 is also connected to a return water pipe 300 that receives the return water from the constant temperature water tank of the pretreatment section of the cleaning water. A second temperature sensor 7 and a second electric shut-off valve 8 are connected sequentially on the return water pipe 300 according to the water flow direction.

[0028] Combining the heat source data such as water temperature, flow rate, pressure, and flow rate in the heated condensate pipe 200 of the main condensate recovery pipeline 100 in the workshop, as well as the measured water temperature (T3 mentioned below), water temperature setpoint (Tsp mentioned below), and water volume parameters obtained from the original machine control system, the opening degree of the flow control valve 1 is controlled, and the first and second electric shut-off valves are opened to create a pressure difference across the two ends of the flow control valve 1. The condensate will then flow into the heated condensate pipe 200 under pressure, and after flowing through the heating coil, it will complete heat exchange in the constant temperature water tank. During this process, the flow rate of the heated condensate pipe 200 is monitored, which means continuously monitoring the condensate flow rate in the heating coil. Afterward, the condensate that has completed the heating process flows back from the constant temperature water tank of the cleaning water pretreatment section to the main condensate recovery pipeline 100 in the workshop through the aforementioned return water pipe 300, and finally flows to the condensate recovery system.

[0029] Based on the above embodiments, it can be noted that the heating coil is preferably made of stainless steel and is installed in the original constant temperature water tank in an immersed manner. Those skilled in the art will understand that, in actual operation, an immersed condensate heating coil is installed at the bottom of the pretreatment section for cleaning water, and inlet and outlet pipes matching the aforementioned condensate are configured.

[0030] In state (1), if 0℃ < T1-T3 < 10℃ (can be set as needed), or P1 < 1MPa (can be set as needed), then the flow control valve 1 will remain fully open, and the two electric shut-off valves will remain closed. This state means that if the condensate water temperature or condensate water pressure is insufficient, the condensate water will not be used to heat the constant temperature water tank. In this case, the original steam heating mode can still be used.

[0031] State (II): If T1-T3≥10℃, P1>1Mpa, and T3<Tsp, it indicates that the condensate has the conditions to heat the water for washing stems. At this time, the water temperature in the tank has not reached the target. In this state, the opening of the flow control valve 1 can be gradually reduced (V1 gradually decreases), and the two electric shut-off valves can be opened. During the process, the pressure difference (P1-P2) between the two ends of the flow control valve 1 can be monitored.

[0032] By adjusting the opening of the flow control valve 1, the pressure difference is maintained within the preset range (P1-P2=1Mpa±0.1);

[0033] When T3 is detected to be close to Tsp, such as Tsp-T3≤5℃, the flow rate in the heated condensate pipe 200 is reduced by adjusting the opening of the flow control valve 1 (the feedback V2 value decreases).

[0034] Until T3 is detected to reach or exceed Tsp, if T3-Tsp≤5℃, the flow control valve 1 is fully opened and the two electric shut-off valves are closed to complete the heating function of condensate to the constant temperature water tank. After the above conditions are met, the condensate heating function can be executed again.

[0035] Finally, one more point to add is that when the tobacco stem cleaning system and the constant temperature hot water system are shut down, the flow control valve 1 remains fully open, and both electric shut-off valves remain closed.

[0036] In summary, during the water pretreatment process of the tobacco stem washing machine, the waste heat of the condensate in the workshop's condensate recovery main pipeline is used to provide heating energy for the washing water. Specifically, the recovered water in the workshop's steam condensate recovery main pipeline is used as a heat source to replace the original steam-heated constant-temperature hot water. In practice, an adjustable flow valve is added to the condensate recovery main pipeline, and three-way branch pipes are installed at both ends of the flow valve. A water-immersed heating coil is installed at the end of one branch pipe, while the other branch pipe is used for heat exchange and return water. Thus, by utilizing the pressure difference formed by the condensate recovery pipeline itself at both ends of the flow valve, the flow rate of condensate flowing into the coil can be dynamically controlled by simply controlling the opening of the main flow valve, thereby achieving heat exchange circulation and controlling the heating rate and temperature of the hot water used for washing the tobacco stems.

[0037] In this invention, when directional terms are mentioned, they are relative concepts based on the embodiments. Furthermore, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0038] The above description of the structure, features, and effects of the present invention is based on the embodiments shown in the figures. However, the above are only preferred embodiments of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched by those skilled in the art to form a variety of equivalent solutions without departing from or changing the design concept and technical effects of the present invention. Therefore, the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A constant temperature hot water control system for preheating heating washing roots using condensate water, characterized by, include: Based on the direction of water flow, the following components are installed sequentially on the main pipeline for condensate recovery in the workshop: a first temperature sensor, a first pressure sensor, a first reducing tee, a flow control valve, a second pressure sensor, and a second reducing tee. The first reducing tee is also connected to a hot condensate pipe that flows to the heating coil, and a first electric shut-off valve is connected to the hot condensate pipe. The second reducing tee is also connected to a return pipe that receives condensate water returning from the constant temperature water tank, and a second electric shut-off valve is connected to the return pipe. Based at least on the water temperature and pressure of the workshop condensate recovery main pipeline, as well as the measured water temperature and water temperature set value of the constant temperature water tank, the opening degree of the flow control valve and the opening and closing of the two electric shut-off valves are controlled so that the condensate in the workshop condensate recovery main pipeline flows into the heated condensate pipe due to the pressure difference across the flow control valve, and after completing the heat exchange in the constant temperature water tank, it flows back to the workshop condensate recovery main pipeline from the return water pipe. The control system specifically includes the following methods for heating and washing stems with constant-temperature hot water: When the difference between the water temperature of the workshop condensate recovery main pipeline and the measured water temperature of the water tank is greater than or equal to the set temperature threshold, and the water pressure before the flow control valve is greater than the set pressure threshold, and the measured water temperature of the water tank is less than the set water temperature value, the opening of the flow control valve is gradually reduced, and two electric shut-off valves are opened, while the pressure difference between the two ends of the flow control valve is monitored during the process. By adjusting the opening of the flow control valve, the pressure difference is maintained within a preset range. When the difference between the set water temperature and the measured water temperature in the water tank is less than or equal to the set difference, the flow rate in the heated condensate pipe is reduced by adjusting the opening of the flow control valve. Until the measured water temperature in the water tank reaches or exceeds the set water temperature value, the flow control valve is fully opened and the two electric shut-off valves are closed. Furthermore, the method of heating the washing stems with constant-temperature hot water in the control system also includes: When the difference between the water temperature in the workshop condensate recovery main pipeline and the measured water temperature in the water tank is greater than 0°C and less than the set temperature threshold, or when the water pressure before the flow control valve is less than the set pressure threshold, the flow control valve is kept fully open and the two electric shut-off valves are kept closed.

2. The constant temperature hot water control system for washing stems using condensate preheating as described in claim 1, characterized in that, A first flow meter is installed on the main pipeline for workshop condensate recovery before the first reducing tee, based on the direction of water flow; and a second flow meter is installed on the heated condensate pipe.

3. The constant temperature hot water control system for washing stems using condensate preheating as described in claim 2, characterized in that, Both the first flow meter and the first flow transducer are electromagnetic flow transmitters.

4. The constant temperature hot water control system for washing stems using condensate preheating as described in claim 1, characterized in that, A second temperature sensor is also connected to the return water pipe.

5. The constant temperature hot water control system for washing stems using condensate preheating as described in any one of claims 1 to 4, characterized in that, The heating coil is made of stainless steel and is installed in the constant temperature water tank by immersion.

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