Control method for heating pipe of heat reservoir

Abstract

The invention discloses a control method for a heating pipe of a heat reservoir, and aims to solve the technical problems that the temperature precision of the current heating pipe for heating molten salt is not high, and the purpose of accurately controlling the temperature cannot be achieved. The structure of the heating pipe comprises a molten salt heat reservoir, a heating pipe, a solid-state relay and a temperature controller; the control method comprises the following steps that S1, a heating pipe is inserted into the molten salt heat reservoir, then the heating pipe, a solid-state relay and a temperature controller are sequentially connected in series through wires, and then a power source is connected to the solid-state relay to be powered on; s2, a solid-state relay preliminarily predicts the fused salt flow according to the total electric heating power of the heating pipe; s3, after the molten salt flow is preliminarily predicted, the power of each stage of heating pipe is distributed according to the total electric heating power of the heating pipe and the preliminarily predicted molten salt flow; and S4, after the power is distributed, distributing a result according to the power of each stage of heating pipe. According to the control method, the reliability, stability and accuracy of heating of the molten salt heat reservoir are greatly improved, and the control method is worthy of popularization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat storage heating pipe, in particular to a control method of heat storage heating pipe. BACKGROUND

[0002] In the prior art, the control method of the molten salt heat storage heating pipe is that the power supply is connected and disconnected to the heating pipe through the on-off of the AC contactor. This method has certain problems. First, since the AC contactor relies on the closing and opening of its main contact to control the heating pipe, a certain current will be generated at the contact point at the moment of closing, which will cause an arc. From the safety point of view, it is not reliable, and if the arc is not handled properly, it will cause a fire. Secondly, from the service life point of view, the number of closing and opening of the AC contactor is limited. Finally, the action time of the AC contactor also has certain requirements. Generally, it takes tens of milliseconds to close and open, which requires that the AC contactor cannot be frequently started and stopped, resulting in low temperature precision of the heating pipe for heating the molten salt, and failing to achieve the purpose of precise temperature control. In order to solve the above problems, the applicant has further researched the heating method of the molten salt heat storage. SUMMARY

[0003] The purpose of the present application is to provide a control method of heat storage heating pipe to solve the technical problem that the temperature precision of the heating pipe for heating the molten salt is not high, and the purpose of precise temperature control cannot be achieved.

[0004] To achieve the above purpose, the present application provides the following technical scheme: a control method of heat storage heating pipe, comprising a molten salt heat storage, a heating pipe, a solid-state relay and a temperature controller. The control steps are as follows:

[0005] S1. First, insert the heating pipe into the inside of the molten salt heat storage, then connect the heating pipe, the solid-state relay and the temperature controller in series through wires, and then connect the power supply to the solid-state relay for power supply;

[0006] S2. Then, the solid-state relay preliminarily predicts the molten salt flow according to the total power of the electric heating of the heating pipe;

[0007] S3. After the molten salt flow is preliminarily predicted, the power of each stage of the heating pipe is distributed according to the total power of the electric heating of the heating pipe and the preliminarily predicted molten salt flow;

[0008] S4. After the power distribution is completed, the outlet temperature of each stage of the heating pipe is predicted by the temperature controller according to the power distribution result of each stage of the heating pipe;

[0009] S5. After the power outlet temperature is predicted, the preliminarily predicted value of the molten salt flow and the molten salt delay flow are corrected according to the outlet temperature prediction value of each stage of the heating pipe;

[0010] S6. After the preliminary prediction of the molten salt flow rate and the corrected delayed molten salt flow rate are determined, the final molten salt flow rate is determined according to the preliminary prediction of the molten salt flow rate, the corrected preliminary prediction of the molten salt flow rate, and the corrected delayed molten salt flow rate.

[0011] S7. After the final molten salt flow rate is determined, the low-temperature molten salt pump frequency is adjusted according to the final molten salt flow rate.

[0012] As a preferred embodiment of the present application, the heating end of the heating pipe is inserted into the interior of the molten salt heat reservoir, the other end of the heating pipe is connected with a solid-state relay through a power supply wire, and the solid-state relay is connected with a temperature controller through a power supply wire.

[0013] As a preferred embodiment of the present application, a plurality of heating pipes are provided and uniformly distributed in the interior of the molten salt heat reservoir.

[0014] As a preferred embodiment of the present application, the solid-state relay is connected with a power supply through a power supply wire.

[0015] As a preferred embodiment of the present application, in step S3, the power of each stage of heating pipe is distributed according to the total power of the electric heating of the heating pipe and the preliminary prediction of the molten salt flow rate, and the specific steps are as follows:

[0016] A1. First, the specific heating requirements of each stage of heater need to be determined, including the temperature range, heating time, and the nature of the heating medium (such as fluid, solid, etc.);

[0017] A2. Calculate the power required for each stage of heating:

[0018] Initial heating power: calculate the power required to heat from the initial temperature to the set temperature within the specified time;

[0019] Temperature maintenance power: calculate the power required to maintain the temperature of the medium unchanged in the case of medium flow rate change or system heat loss;

[0020] A3. Select the type and number of heaters: according to the calculation results, select the appropriate type and number of heaters to ensure that the total power can meet the maximum power requirement;

[0021] A4. Finally, the power of each stage of heating pipe is distributed.

[0022] As a preferred embodiment of the present application, the distribution of the power of each stage of heating pipe also includes considering the actual installation and use conditions: in the actual installation and use process, it may also be necessary to consider the influence of environmental temperature, power supply conditions, and the actual installation position of the heater on the power distribution;

[0023] Safety margin consideration: To ensure the safety and reliability of the heating system, a certain safety margin is usually added to the calculated power, and 1.2 is usually taken as the safety factor;

[0024] Power regulation mode: Electromagnetic heaters provide various ways to regulate power, such as frequency modulation method, gap heating method, etc. These methods can flexibly adjust the power output of each level of heater according to actual needs.

[0025] As a preferred embodiment of the present application, the outlet temperature of each level of heating tube is predicted by the temperature controller in step S4. First, the temperature sensor is responsible for measuring the actual temperature of the heating tube outlet, and these data are transmitted to the temperature controller. The temperature controller adjusts the power output of the heating tube according to the received temperature information and the preset control algorithm to control and predict the outlet temperature.

[0026] As a preferred embodiment of the present application, the outlet temperature of each level of heating tube is predicted by the temperature controller in step S4.

[0027] Temperature measurement: Temperature sensors (such as thermal resistance, thermocouple or infrared thermometer) are placed at the outlet of the heating tube to directly measure the outlet temperature.

[0028] The role of the temperature controller: The temperature controller receives signals from the temperature sensor and adjusts the heating power of the heating tube through the internal preset control logic. If the measured temperature is lower than the set value, the temperature controller will send a signal to increase the heating power; otherwise, it will reduce the heating power to maintain the outlet temperature within the set range.

[0029] Power control: The temperature controller needs to be used with solid-state relays to achieve rapid and accurate adjustment of heating power. The solid-state relay controls the power output of the heater quickly and linearly according to the instructions of the temperature controller, so as to achieve the purpose of accurate temperature control.

[0030] Prediction and control: By collecting historical temperature data and real-time temperature data, combined with control algorithms (such as PID control algorithm), the outlet temperature of the heating tube is predicted and the heating power is adjusted in advance to prevent temperature fluctuations from being too large or exceeding the safety range.

[0031] Compared with the prior art, the beneficial effects of the present application are as follows:

[0032] 1、The solid-state relay main contact of the present application is a passive contact and will not produce arc, and the action time of the solid-state relay is relatively short, and the number of closing and opening is not limited, so as to achieve the effect of frequent start and stop.

[0033] 2、The control method greatly improves the reliability, stability and accuracy of the heating of the molten salt heat reservoir, and is worth promoting. BRIEF DESCRIPTION OF DRAWINGS

[0034] Other features, objects, and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments, when read in conjunction with the accompanying drawings:

[0035] Figure 1 is a structural schematic diagram of the present application;

[0036] In the figure: 1, molten salt heat reservoir; 2, heating pipe; 3, solid-state relay; 4, temperature controller. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0038] Embodiment 1: A control method for a heat reservoir heating pipe, referring to Figure 1 , comprising a molten salt heat reservoir, a heating pipe, a solid-state relay and a temperature controller; the control steps are as follows:

[0039] S1. First, insert the heating pipe into the inside of the molten salt heat reservoir, then sequentially connect the heating pipe, the solid-state relay and the temperature controller through wires, and then connect the power supply to the solid-state relay for power-on;

[0040] S2. Then, preliminarily predict the molten salt flow rate from the solid-state relay according to the total power of the electric heating of the heating pipe;

[0041] S3. After the preliminary prediction of the molten salt flow rate, distribute the power of each stage of the heating pipe according to the total power of the electric heating of the heating pipe and the preliminary prediction of the molten salt flow rate;

[0042] S4. After the power distribution, predict the outlet temperature of each stage of the heating pipe through the temperature controller according to the power distribution results of each stage of the heating pipe;

[0043] S5. After the power outlet temperature is predicted, correct the preliminary prediction value of the molten salt flow rate and the molten salt delay flow rate according to the outlet temperature prediction value of each stage of the heating pipe;

[0044] S6. After the preliminary prediction value of the molten salt flow rate and the molten salt delay flow rate are corrected, determine the final molten salt flow rate according to the preliminary prediction value of the molten salt flow rate, the corrected preliminary prediction value of the molten salt flow rate and the corrected molten salt delay flow rate;

[0045] S7. After the final molten salt flow rate is determined, adjust the low-temperature molten salt pump frequency according to the final molten salt flow rate.

[0046] Specifically, referring to Figure 1 , the heating end of the heating pipe is inserted into the inside of the molten salt heat reservoir, the other end of the heating pipe is connected with a solid-state relay through a power supply wire, and the solid-state relay is connected with a temperature controller through a power supply wire.

[0047] Further, referring to Figure 1 , the heating pipe is provided in plurality and uniformly distributed in the inside of the molten salt heat reservoir.

[0048] Still further, referring to Figure 1 , the solid-state relay is connected with a power supply through a power supply wire.

[0049] It is worth noting that the power of each stage of the heating pipe is allocated according to the total power of the electric heating of the heating pipe and the preliminary predicted molten salt flow in step S3, and the specific steps are as follows:

[0050] A1. First, the specific heating requirements of each stage of the heater need to be determined, including temperature range, heating time, and the nature of the heating medium (such as fluid, solid, etc.);

[0051] A2. Calculate the power required for each stage of heating:

[0052] Initial heating power: calculate the power required to heat from the initial temperature to the set temperature within the specified time;

[0053] Temperature maintenance power: calculate the power required to maintain the temperature of the medium unchanged in the case of medium flow change or system heat loss;

[0054] A3. Select the type and number of heaters: according to the calculation results, select the appropriate type and number of heaters to ensure that the total power can meet the maximum power requirement;

[0055] A4. Finally, the power of each stage of the heating pipe is allocated.

[0056] It is worth noting that the allocation of power to each stage of the heating pipe also includes considering the actual installation and use conditions: in the actual installation and use process, it may also be necessary to consider the influence of environmental temperature, power supply conditions, and the actual installation position of the heater on the power allocation;

[0057] Safety margin: in order to ensure the safety and reliability of the heating system, a certain safety margin will be added to the calculated power, usually taking 1.2 as the safety factor;

[0058] Power regulation methods: electromagnetic heaters provide multiple ways to regulate power, such as frequency modulation, gap heating, etc. These methods can flexibly adjust the power output of each level of heater according to actual needs.

[0059] It is worth mentioning that the step S4 predicts the outlet temperature of each level of heating tube through the temperature controller. First, the temperature sensor measures the actual temperature of the heating tube outlet, and these data are transmitted to the temperature controller. The temperature controller adjusts the power output of the heating tube according to the received temperature information and the preset control algorithm to control and predict the outlet temperature.

[0060] It is worth emphasizing that the step S4 predicts the outlet temperature of each level of heating tube through the temperature controller.

[0061] Temperature measurement: temperature sensors (such as thermal resistance, thermocouple or infrared thermometer) are placed at the outlet of the heating tube to directly measure the outlet temperature.

[0062] The role of the temperature controller: the temperature controller receives signals from the temperature sensor and adjusts the heating power of the heating tube through the internal preset control logic. If the measured temperature is lower than the set value, the temperature controller will send a signal to increase the heating power; otherwise, it will reduce the heating power to maintain the outlet temperature within the set range.

[0063] Power control: the temperature controller needs to be used with solid-state relays to achieve rapid and accurate adjustment of heating power. The solid-state relay controls the power output of the heater quickly and linearly according to the instructions of the temperature controller, so as to achieve the purpose of accurate temperature control.

[0064] Prediction and control: by collecting historical temperature data and real-time temperature data, combined with control algorithms (such as PID control algorithm), the outlet temperature of the heating tube is predicted and the heating power is adjusted in advance to prevent temperature fluctuations from being too large or exceeding the safety range.

[0065] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be realized in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be considered as limiting the claims involved.

[0066] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature or implementation described herein. The specification can include implicit combinations of explicitly mentioned features and / or implicit combinations of implicitly mentioned features. Such combinations are also expressly included within the scope of the specification and an embodiment.

Claims

1. A method of controlling a heat bank heating pipe, characterized by: The heating tube is inserted into the inside of the molten salt heat reservoir, and the heating tube and the solid-state relay are connected in series through the power supply line. S1. First, the heating tube is inserted into the inside of the molten salt heat reservoir, and then the heating tube and the solid-state relay are connected in series through the power supply line, and the power supply is connected to the solid-state relay for power supply; S2. Then, the solid-state relay preliminarily predicts the molten salt flow rate according to the total power of the heating tube; S3. After the molten salt flow rate is preliminarily predicted, the power of each stage of the heating tube is distributed according to the total power of the heating tube and the preliminarily predicted molten salt flow rate; S4. After the power distribution is completed, the outlet temperature of each stage of the heating tube is predicted by the temperature controller according to the power distribution results of each stage of the heating tube; S5. After the outlet temperature is predicted, the preliminary prediction value of the molten salt flow rate and the molten salt delay flow rate are corrected according to the outlet temperature prediction value of each stage of the heating tube; S6. After the preliminary prediction value of the molten salt flow rate and the molten salt delay flow rate are corrected, the final molten salt flow rate is determined according to the preliminary prediction value of the molten salt flow rate, the corrected preliminary prediction value of the molten salt flow rate, and the corrected molten salt delay flow rate; S7. After the final molten salt flow rate is determined, the low-temperature molten salt pump frequency is adjusted according to the final molten salt flow rate.

2. The control method of a heat storage heating pipe according to claim 1, characterized by: The heating end of the heating tube is inserted into the inside of the molten salt heat reservoir, and the other end of the heating tube is connected with the solid-state relay through the power supply line, and the solid-state relay is connected with the temperature controller through the power supply line.

3. The method of claim 2, wherein: The heating tube is provided with a plurality of heating tubes, which are uniformly distributed in the inside of the molten salt heat reservoir.

4. The method of claim 1, wherein: The solid-state relay is connected with the power supply through the power supply line.

5. The method of claim 1, wherein: In step S3, the power of each stage of the heating tube is distributed according to the total power of the heating tube and the preliminarily predicted molten salt flow rate, and the specific steps are as follows: A1. First, the specific heating requirements of each stage of the heater need to be determined, including the temperature range, the heating time, and the properties of the heating medium; A2. Calculate the power required for each stage of heating: Initial heating power: calculate the power required to heat from the initial temperature to the set temperature within the specified time; Temperature maintenance power: calculate the power required to maintain the medium temperature unchanged under the condition that the medium flow rate changes or the system has heat loss; A3. Select the type and number of heaters: according to the calculation results, select the appropriate type and number of heaters to ensure that the total power can meet the maximum power requirement; A4. Finally, the power of each stage of the heating tube is distributed.

6. The method of claim 5, wherein: The power distribution of each stage of the heating tube also includes considering the actual installation and use conditions: in the actual installation and use process, the influence of environmental temperature, power supply conditions, and the actual installation position of the heater on the power distribution is considered; Safety margin: in order to ensure the safety and reliability of the heating system, a certain safety margin is generally added to the calculated power, and 1.2 is usually taken as the safety factor; Power regulation mode: electromagnetic heaters provide multiple ways to regulate power, such as frequency modulation method and gap heating method, which can flexibly adjust the power output of each stage of the heater according to actual needs.

7. The method of claim 1, wherein: The step S4 predicts the outlet temperature of each stage of heating tube through the temperature controller. First, the temperature sensor measures the actual temperature at the outlet of the heating tube. These data are transmitted to the temperature controller. The temperature controller adjusts the power output of the heating tube based on the received temperature information and the preset control algorithm to control and predict the outlet temperature.

8. The method of claim 7, wherein: The step S4 predicts the outlet temperature of each stage of heating tube through the temperature controller. Temperature measurement: The temperature sensor is placed at the outlet of the heating tube to directly measure the outlet temperature. The role of the temperature controller: The temperature controller receives signals from the temperature sensor and adjusts the heating power of the heating tube through the internal preset control logic. If the measured temperature is lower than the set value, the temperature controller will send a signal to increase the heating power. Conversely, it will reduce the heating power to maintain the outlet temperature within the set range. Power control: The temperature controller needs to be used with a solid-state relay to achieve rapid and accurate adjustment of the heating power. The solid-state relay controls the power output of the heater quickly and linearly according to the instructions of the temperature controller, thereby achieving accurate temperature control. Prediction and control: By collecting historical temperature data and real-time temperature data, the outlet temperature of the heating tube is predicted and the heating power is adjusted in advance to prevent large temperature fluctuations or exceed the safety range.

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