Water mixing heat exchanger control system and control method thereof

Abstract

The invention relates to the technical field of central heating and industrial heat energy utilization, in particular to a mixed water heat exchanger control system and a control method thereof.The mixed water heat exchanger control system comprises a jet type mixed water heat exchanger, a first high-temperature water jet channel, a second low-temperature water jet channel and a mixing cavity are formed in the jet type mixed water heat exchanger; the primary net adjusting unit comprises an electric adjusting valve and a pressure sensor which are arranged at a primary high-temperature water inlet; the secondary network circulating unit comprises a circulating pump, a flow sensor and a return water temperature sensor; the temperature detection unit at least comprises a mixed outlet water temperature sensor; the controller is in signal connection with the electric adjusting valve, the circulating pump and the sensors; synchronous efficient utilization of primary network heat energy and pressure energy is achieved, the heat exchange efficiency can be close to 100%, secondary low-temperature water can be effectively driven by the pressure energy of primary high-temperature water to participate in mixing through the injection pressurization characteristic of the injection type water mixing heat exchanger, and the operation power of a secondary network circulating pump is reduced.

Description

Technical Field

[0001] This invention relates to the field of centralized heating and industrial heat energy utilization technology, and in particular to a mixing water heat exchanger control system and its control method. Background Technology

[0002] In existing centralized heating systems, plate heat exchangers are often used for indirect heat exchange between the primary and secondary heating networks. This type of system has the following drawbacks: Pressure cannot be transmitted, and the pressure of the primary water supply is wasted during the heat exchange process. Heat exchange efficiency is limited, typically around 90% to 93%; The high temperature of the primary network return water results in a small temperature difference between the supply and return water, leading to low heat source transmission efficiency. The system relies on high flow rates, resulting in high energy consumption of the circulating pump and significant equipment investment and operating costs.

[0003] Jet-type mixing heat exchangers achieve simultaneous utilization of thermal and pressure energy by directly mixing primary high-temperature water and secondary low-temperature water in a mixing chamber, with a heat exchange efficiency approaching 100%. However, in practical engineering applications, without a matching dynamic control system, problems such as fluctuating supply water temperature, unstable operation, or failure to fully realize energy-saving potential may occur.

[0004] Therefore, it is necessary to propose a control system and control method specifically for mixed water heat exchangers to achieve stable, safe and efficient operation. Summary of the Invention

[0005] The purpose of this invention is to provide a control system and control method for a mixing water heat exchanger.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A mixing water heat exchanger control system, comprising: The jet-type mixing heat exchanger has a primary high-temperature water jet channel, a secondary low-temperature water ejection channel, and a mixing chamber inside. The primary network regulating unit includes an electric regulating valve and a pressure sensor installed at the primary high-temperature water inlet; The secondary network circulation unit includes a circulation pump, a flow sensor, and a return water temperature sensor; Temperature detection unit, including at least a mixed outlet water temperature sensor; The controller is connected to the electric regulating valve, the circulating pump, and each sensor signal respectively; The controller adjusts the primary network spray flow rate and the secondary network circulation flow rate based on the target temperature of the mixed effluent to control the mixing ratio of the primary high-temperature water and the secondary low-temperature water.

[0007] Preferably, the controller adopts a multi-parameter closed-loop control method, and simultaneously introduces the supply water temperature, return water temperature and primary network pressure as control variables; Under low load conditions, the primary network jet flow rate should be reduced first in order to increase the temperature difference between the primary network supply and return water. In extremely cold or high-load conditions, by increasing the primary network injection pressure, the operating frequency of the secondary network circulation pump can be reduced.

[0008] Based on the above system, the present invention also provides a method for controlling a mixing water heat exchanger, comprising the following steps: Target temperature setting: Set the target temperature of the mixed outlet water according to the outdoor temperature or heating dispatch instructions; Parameter acquisition: Real-time acquisition of primary network pressure, primary network flow rate, secondary network return water temperature, and mixed outlet water temperature; Deviation calculation: The measured temperature of the mixed effluent is compared with the target temperature to obtain the temperature deviation; Coordinated Regulation: When the temperature of the mixed effluent is lower than the target value, increase the primary network spray flow rate or decrease the secondary network circulation flow rate. When the temperature of the mixed effluent is higher than the target value, reduce the primary network spray flow rate or increase the secondary network circulation flow rate. Pressure energy optimization: Under the premise of meeting the water supply temperature, the pressure energy of the primary network is used first to reduce the speed of the secondary network circulation pump; Stable operation control: Through continuous feedback adjustment, the system operating parameters are kept stable within the set range.

[0009] The present invention has at least the following beneficial effects: It achieves simultaneous and efficient utilization of primary network thermal energy and pressure energy, with heat exchange efficiency approaching 100%. It significantly reduces the temperature of the primary network return water, widens the temperature difference between the supply and return water, and improves the heat source transmission capacity; To reduce the primary network flow and the energy consumption of the secondary network circulation pump under the same heating load; The system has a compact structure and clear control logic, making it suitable for new construction or renovation of existing heating stations. Improve the overall operational stability and economy of the heating system. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1This is a schematic diagram of the control system for a mixing water heat exchanger. Figure 2 This is a schematic diagram of the improved structure of the mixing water heat exchanger control system.

[0012] In the diagram: 1. Jet-type mixing heat exchanger; 11. Primary high-temperature water jet channel; 12. Secondary low-temperature water jet channel; 13. Mixing chamber; 2. Primary network regulating valve; 3. Secondary network circulation pump; 4. Mixed outlet water temperature sensor; 5. Controller; 6. Return water temperature sensor; 7. Pressure detection element. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0014] Example 1: like Figure 1 As shown in the figure, this embodiment discloses a mixing water heat exchanger control system, including a jet mixing water heat exchanger 1, a primary network regulating valve 2, a secondary network circulating pump 3, a mixed outlet water temperature sensor 4, and a controller 5.

[0015] The jet-type mixing heat exchanger 1 is provided with a primary high-temperature water jet channel 11, a secondary low-temperature water jet channel 12, and a mixing chamber 13 located at the confluence of the two channels. The primary high-temperature water enters the mixing chamber 13 through the primary high-temperature water jet channel 11, and the secondary low-temperature water enters the mixing chamber 13 through the secondary low-temperature water jet channel 12. After direct mixing and heat exchange in the mixing chamber 13, mixed outlet water is formed.

[0016] The primary network regulating valve 2 is installed on the primary high-temperature water jet channel 11 and is used to regulate the flow rate of the primary high-temperature water entering the jet-type mixing heat exchanger 1. In this embodiment, the primary network regulating valve 2 is an electric regulating valve, and its opening degree is controlled by the controller 5.

[0017] The secondary network circulation pump 3 is installed in the secondary cryogenic water circuit to drive the secondary cryogenic water to circulate in the system. In this embodiment, the secondary network circulation pump 3 is a variable frequency circulation pump, and its operating frequency is adjusted by the controller 5.

[0018] The mixed water temperature sensor 4 is installed at the outlet of the mixing chamber 13 to detect the mixed water temperature in real time and send the detected temperature signal to the controller 5.

[0019] The controller 5 is electrically connected to the primary network regulating valve 2, the secondary network circulating pump 3, and the mixed outlet water temperature sensor 4, respectively, and is used to adjust the system operating status according to the mixed outlet water temperature.

[0020] Example 2 Based on Example 1, such as Figure 2 As shown, in this embodiment, a return water temperature sensor 6 is further installed on the secondary low-temperature water circuit. The return water temperature sensor 6 is electrically connected to the controller 5 and is used to detect the return water temperature of the secondary network.

[0021] Meanwhile, a pressure detection element 7 is installed on the primary high-temperature water jet channel 11. The pressure detection element 7 is electrically connected to the controller 5 and is used to detect the pressure status of the primary high-temperature water before it enters the jet-type mixing heat exchanger 1.

[0022] By introducing a return water temperature sensor 6 and a pressure detection element 7, the controller 5 can make the system operation more stable when adjusting the primary network regulating valve 2 and the secondary network circulation pump 3, and avoid large fluctuations in the mixed outlet water temperature.

[0023] Example 3: Example of a control method for a mixing water heat exchanger Based on the above-described mixing heat exchanger control system, this embodiment also provides a mixing heat exchanger control method, which specifically includes the following steps: Step S1: Start the mixing water heat exchanger control system, and the controller 5 acquires the mixed water temperature detected by the mixed water temperature sensor 4.

[0024] Step S2: The controller 5 compares the mixed water temperature with the preset target temperature.

[0025] Step S3: When the mixed outlet water temperature is lower than the target temperature, the controller 5 controls the primary network regulating valve 2 to increase the opening degree and / or increases the operating frequency of the secondary network circulation pump 3; When the temperature of the mixed effluent is higher than the target temperature, the controller 5 controls the primary network regulating valve 2 to reduce its opening and / or reduces the operating frequency of the secondary network circulating pump 3.

[0026] Step S4: By adjusting the primary network regulating valve 2 and the secondary network circulating pump 3, the mixed water temperature returns to the set range corresponding to the target temperature, thereby achieving stable operation of the mixed water heat exchanger.

[0027] Throughout the entire control process, the primary high-temperature water and the secondary low-temperature water are always directly mixed and exchanged for heat within the jet-type mixing heat exchanger 1.

[0028] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A control system for a mixing water heat exchanger, characterized in that, include: The jet-type mixing heat exchanger (1) is provided with a primary high-temperature water jet channel (11), a secondary low-temperature water ejection channel (12), and a mixing chamber (13) for direct mixing of primary high-temperature water and secondary low-temperature water. A primary network regulating valve (2) is installed on the primary high-temperature water jet channel (11); A secondary network circulation pump (3) is installed on the secondary low-temperature water circuit; A mixing outlet water temperature sensor (4) is installed at the outlet end of the mixing chamber (13); The controller (5) is electrically connected to the primary network regulating valve (2), the secondary network circulating pump (3), and the mixed outlet water temperature sensor (4), respectively. The controller (5) adjusts the opening of the primary network regulating valve (2) and the operating status of the secondary network circulating pump (3) based on the mixed outlet water temperature detected by the mixed outlet water temperature sensor (4) so ​​as to keep the mixed outlet water temperature within the set range.

2. The mixing water heat exchanger control system according to claim 1, characterized in that, The primary network regulating valve (2) is an electric regulating valve.

3. The mixing water heat exchanger control system according to claim 1, characterized in that, The secondary network circulation pump (3) is a variable frequency circulation pump.

4. The mixing water heat exchanger control system according to claim 1, characterized in that, The mixing water heat exchanger control system also includes a return water temperature sensor (6) installed on the secondary low-temperature water circuit, and the return water temperature sensor (6) is electrically connected to the controller (5).

5. The control system and control method for a mixing water heat exchanger according to claim 1, characterized in that, The mixing water heat exchanger control system also includes a pressure detection element (7) installed on the primary high-temperature water jet channel (11), and the pressure detection element (7) is electrically connected to the controller (5).

6. A method for controlling a mixing water heat exchanger, applied to the mixing water heat exchanger control system according to any one of claims 1 to 5, characterized in that, Includes the following steps: 1) Obtain the temperature of the mixed effluent; 2) Compare the mixed outlet water temperature with the preset target temperature; 3) When the temperature of the mixed outlet water deviates from the target temperature, adjust the opening of the primary network regulating valve (2) and / or the operating status of the secondary network circulating pump (3); 4) By adjusting in step 3), the temperature of the mixed outlet water is brought back to the set range corresponding to the target temperature.

7. The method for controlling a mixing water heat exchanger according to claim 6, characterized in that: In step 3), adjusting the operating status of the secondary network circulation pump (3) includes adjusting the operating frequency of the circulation pump.

8. The method for controlling a mixing water heat exchanger according to claim 6, characterized in that: The control method allows primary high-temperature water and secondary low-temperature water to directly mix and exchange heat in the jet-type mixing heat exchanger during heating operation.

Images