Thermal power plant heat supply network circulating pump control system

Abstract

The utility model relates to a thermal power plant heat supply network circulating pump control system which comprises a first circulating pump, a second circulating pump, a first frequency converter used for driving the first circulating pump, a second frequency converter used for driving the second circulating pump and a timing control switch. A first electric control switch, a second electric control switch, a third electric control switch, a first power supply, a second power supply and a third power supply; according to the utility model, the timing control switch is adopted to drive the first electric control switch to act in a timing manner, so that the polling between the first circulating pump and the second circulating pump is realized by controlling the connection and disconnection of the second electric control switch and the third electric control switch; the two circulating pumps run in turn, and the problem that the service lives of the heat supply network circulating pumps and frequency converters are shortened due to long-time running of the main heat supply network circulating pump and long-time non-running of the standby heat supply network circulating pump is solved.

Description

Technical Field

[0001] The utility model relates to the field of circulating pump control, and particularly relates to a heat network circulating pump control system for a thermal power plant. Background Art

[0002] In a thermal power plant, a heat network circulating pump is mainly used to transport heat medium, adjust the heat balance of the system, ensure that the temperature inside the power plant is stably within a suitable range, and thus guarantee the stability of power production. It enables the efficient utilization of the heat energy of the power plant by continuously circulating and transporting heat medium such as hot water or steam.

[0003] However, in the prior art, most heat network circulating pumps adopt a one - main - one - standby setting method, resulting in the long - term operation of the main heat network circulating pump and the long - term non - operation of the standby heat network circulating pump. Due to the long - term non - operation of the standby heat network circulating pump, its seals lose their resilience due to being in a compressed state for a long time, leading to seal failure. Seal failure will cause leakage, affecting the performance and efficiency of the pump. Moreover, components such as ball bearings in the bearing part are exposed for a long time, increasing the noise and vibration of the pump, and even possibly causing shaft bending, breakage, or motor overload and burnout. On the other hand, due to long - term use, the main heat network circulating pump ages more severely, and its corresponding frequency converter ages faster due to long - term operation, so the service life of the main heat network circulating pump and its frequency converter is significantly reduced. Summary of the Utility Model

[0004] In view of this, the utility model aims to propose a heat network circulating pump control system for a thermal power plant to solve the problem in the prior art that the main heat network circulating pump operates for a long time and the standby heat network circulating pump does not operate for a long time, resulting in the shortened service life of the heat network circulating pump and its frequency converter.

[0005] To achieve the above object, the technical solution of the utility model is realized as follows:

[0006] The utility model provides a heat network circulating pump control system for a thermal power plant, including a first circulating pump, a second circulating pump, a first frequency converter for driving the first circulating pump, and a second frequency converter for driving the second circulating pump, and further including:

[0007] A timing control switch, a first electric control switch, a second electric control switch, a third electric control switch, a first power supply, a second power supply, and a third power supply;

[0008] One end of the first power supply is connected to the first power supply end of the timing control switch and one end of the relay output end, the other end of the relay output end of the timing control switch is connected to one end of the driving end of the first electric control switch, and the second end is connected to the second power supply end of the timing control switch and the other end of the driving end of the first electric control switch;

[0009] The first end of the second power supply is connected to one end of the normally open contact of the first electric control switch and one end of the normally closed contact of the first electric control switch; the other end of the normally open contact of the first electric control switch is connected to one end of the driving end of the second electric control switch, and the other end of the normally closed contact is connected to one end of the driving end of the third electric control switch. The second end of the second power supply is connected to the other end of the driving end of the second electric control switch and the other end of the driving end of the third electric control switch;

[0010] The first end of the third power supply is connected to one end of the normally open contact of the second electric control switch and one end of the normally open contact of the third electric control switch; the other end of the normally open contact of the second electric control switch is connected to the start input end of the first frequency converter; the other end of the normally open contact of the third electric control switch is connected to the start input end of the second frequency converter. The second end of the third power supply is connected to the start output end of the first frequency converter and the start output end of the second frequency converter.

[0011] Further, the timing control switch is a cyclic countdown switch.

[0012] Further, the second electric control switch and the third electric control switch are respectively power-off delay relays.

[0013] Further, the heat supply network circulating pump control system of the thermal power plant further includes a first cumulative timer and a second cumulative timer;

[0014] The start output end of the first frequency converter is connected to one end of the first cumulative timer;

[0015] The start output end of the second frequency converter is connected to one end of the second cumulative timer;

[0016] The second end of the third power supply is connected to the other end of the first cumulative timer and the other end of the second cumulative timer.

[0017] Further, the heat supply network circulating pump control system of the thermal power plant further includes a first temperature sensor and a second temperature sensor;

[0018] The first temperature sensor is arranged on the first frequency converter and is used for monitoring the temperature of the first frequency converter;

[0019] The second temperature sensor is arranged on the second frequency converter and is used for monitoring the temperature of the second frequency converter.

[0020] Further, the heat supply network circulating pump control system of the thermal power plant further includes a fourth power supply, a first temperature control switch, a second temperature control switch and a fourth electric control switch;

[0021] The first temperature sensor is connected to the analog quantity receiving end of the first temperature control switch, and the second temperature sensor is connected to the analog quantity receiving end of the second temperature control switch; the first end of the fourth power supply is connected to the first power input end and the first output end of the first temperature control switch and one end of the first output end of the second temperature control switch; one end of the driving end of the fourth electric control switch is connected to the other end of the first output end of the first temperature control switch and the other end of the first output end of the second temperature control switch, and the other end of the driving end of the fourth electric control switch, the second power input end of the first temperature control switch, and the first power input end of the second temperature control switch are respectively connected to the second end of the fourth power supply;

[0022] The other end of the normally closed contact of the first electric control switch is connected to one end of the first normally open contact and one end of the first normally closed contact of the fourth electric control switch; the other end of the normally open contact of the first electric control switch is connected to one end of the second normally open contact and one end of the second normally closed contact of the fourth electric control switch; the other end of the first normally open contact and the other end of the second normally closed contact of the fourth electric control switch are connected to one end of the driving end of the second electric control switch; the other end of the second normally open contact and the other end of the first normally closed contact of the fourth electric control switch are connected to one end of the driving end of the third electric control switch.

[0023] Further, the fourth electric control switch is a relay.

[0024] Further, the heat supply network circulation pump control system of the thermal power plant further includes a first radiator and a second radiator; the first end of the fourth power supply is connected to one end of the second output end of the first temperature control switch and one end of the second output end of the second temperature control switch; the other end of the second output end of the first temperature control switch is connected to one end of the first radiator, and the other end of the second output end of the second temperature control switch is connected to one end of the second radiator; the other end of the first radiator and the other end of the second radiator are connected to the second end of the fourth power supply.

[0025] Further, a first check valve is connected to the output end of the first circulation pump;

[0026] A second check valve is connected to the output end of the second circulation pump.

[0027] Further, the first electric control switch is a relay.

[0028] Compared with the prior art, the utility model has the following advantages:

[0029] In the present utility model, a timing control switch is used to drive the first electric control switch to act at a fixed time, and then by controlling the on and off of the second electric control switch and the third electric control switch, the polling between the first circulating pump and the second circulating pump is realized; the two circulating pumps operate alternately, avoiding the problem that the main heat network circulating pump runs for a long time and the standby heat network circulating pump does not run for a long time, resulting in the shortening of the service life of the heat network circulating pump and its frequency converter. Description of the Drawings

[0030] The drawings forming a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0031] Figure 1 is the circuit diagram of the timing control loop of the first embodiment of the heat network circulating pump control system of the thermal power plant of the present utility model;

[0032] Figure 2 is the circuit diagram of the frequency converter control loop of the first embodiment of the heat network circulating pump control system of the thermal power plant of the present utility model;

[0033] Figure 3 is the circuit diagram of the frequency converter power supply loop of the first embodiment of the heat network circulating pump control system of the thermal power plant of the present utility model;

[0034] Figure 4 is the circuit diagram of the frequency converter control loop of the second embodiment of the heat network circulating pump control system of the thermal power plant of the present utility model;

[0035] Figure 5 is the circuit diagram of the frequency converter power supply loop of the second embodiment of the heat network circulating pump control system of the thermal power plant of the present utility model;

[0036] Figure 6 is the circuit diagram of the temperature control loop of the third embodiment of the heat network circulating pump control system of the thermal power plant of the present utility model;

[0037] Figure 7 is the circuit diagram of the frequency converter control loop of the third embodiment of the heat network circulating pump control system of the thermal power plant of the present utility model;

[0038] Figure 8 is the water circuit connection diagram of the circulating pump of the heat network circulating pump control system of the thermal power plant of the present utility model. Detailed Embodiments

[0039] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0040] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "back", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0041] In addition, in the description of the present utility model, unless otherwise clearly defined, the terms "installation", "connection", "connection", "connector" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood in combination with specific situations.

[0042] The following will refer to the attached Figures 1 to 8 and describe the present utility model in detail in conjunction with embodiments.

[0043] Overall, a control system for a heat network circulation pump in a thermal power plant includes a first circulation pump, a second circulation pump, a first frequency converter VDF1 for driving the first circulation pump, and a second frequency converter VDF2 for driving the second circulation pump. It further includes:

[0044] a timing control switch, a first electric control switch KA1, a second electric control switch KA2, a third electric control switch KA3, a first power supply, a second power supply, and a third power supply;

[0045] As Figure 1 shown, the first end L1 of the first power supply is connected to one end K1 of the relay output of the first power supply end D1 of the timing control switch. The other end K2 of the relay output of the timing control switch is connected to one end of the driving end of the first electric control switch KA1. The second end N1 is connected to the second power supply end D2 of the timing control switch and the other end of the driving end of the first electric control switch KA1;

[0046] As Figure 2 shown, the first end L2 of the second power supply is connected to one end of the normally open contact and one end of the normally closed contact of the first electric control switch KA1; the other end of the normally open contact of the first electric control switch KA1 is connected to one end of the driving end of the second electric control switch KA2, and the other end of the normally closed contact is connected to one end of the driving end of the third electric control switch KA3. The second end N2 of the second power supply is connected to the other end of the driving end of the second electric control switch KA2 and the other end of the driving end of the third electric control switch KA3;

[0047] As Figure 3As shown in the figure, the first end L3 of the third power supply is connected to one end of the normally open contact of the second electric control switch KA2 and one end of the normally open contact of the third electric control switch KA3; the other end of the normally open contact of the second electric control switch KA2 is connected to the start input end of the first frequency converter VDF1; the other end of the normally open contact of the third electric control switch KA3 is connected to the start input end of the second frequency converter VDF2, and the second end of the third power supply is connected to the start output end of the first frequency converter VDF1 and the start output end of the second frequency converter VDF2.

[0048] The working principle of this embodiment is as follows: The user sets the preset countdown time of the timing control switch. When the countdown time reaches the preset value, the timing control switch restarts the countdown. The relay output end of the timing control switch is turned on, and the driving end of the first electric control switch KA1 is powered on and driven, its normally open contact closes, and its normally closed contact opens, so that the driving end of the second electric control switch KA2 is powered on, the normally open contact of the second electric control switch KA2 closes, and the first frequency converter VDF1 starts. The driving end of the third electric control switch KA3 loses power, and the normally open contact of the third electric control switch KA3 opens, so that the second frequency converter VDF2 stops; when the next countdown time reaches the preset value, the timing control switch restarts the countdown, and the relay output end of the timing control switch is turned off. The driving end of the first electric control switch KA1 loses power, its normally open contact opens, and its normally closed contact closes; at this time, the driving end of the second electric control switch KA2 loses power, so that the normally open contact of the second electric control switch KA2 opens, the first frequency converter VDF1 stops, and at the same time the driving end of the third electric control switch KA3 is powered on, so that the normally open contact of the third electric control switch KA3 closes, and the second frequency converter VDF2 starts; thus realizing the polling between the two circulating pumps. The countdown time can be one hour, one day or three days, etc.

[0049] The utility model uses a timing control switch to drive the first electric control switch KA1 to act regularly, and then realizes the polling between the first circulating pump and the second circulating pump by controlling the on and off of the second electric control switch KA2 and the third electric control switch KA3; the two circulating pumps run alternately, avoiding the problem that the main heat network circulating pump runs for a long time and the standby heat network circulating pump does not run for a long time, resulting in the shortening of the service life of the heat network circulating pump and its frequency converter.

[0050] In a possible implementation manner, the timing control switch is a cyclic countdown switch.

[0051] In this embodiment, the timing control switch can be selected as a cyclic countdown switch or a time control switch. Among them, the time control switch can be configured to turn on or off a certain device at multiple time periods; while the cyclic countdown switch can turn on or off a certain device when the preset time arrives. In this embodiment, since the first circulation pump and the second circulation pump do not require time control and only need to poll between the two circulation pumps at a fixed time, therefore, this embodiment preferably selects a cyclic countdown switch. In addition, the model of the cyclic countdown switch in this embodiment can be selected as CN102A.

[0052] In a possible implementation manner, the second electric control switch KA2 and the third electric control switch KA3 are respectively power-off delay relays.

[0053] In this embodiment, as Figure 4 and Figure 5 shown, where the second electric control switch KA2 is the first power-off delay relay KT1, and the third electric control switch KA3 is the second power-off delay relay KT2; the specific working principle is as follows: when the countdown time reaches the preset value, the timing control switch restarts the countdown, the relay output end of the timing control switch conducts, the driving end of the first electric control switch KA1 is powered on and driven, its normally open contact closes, and its normally closed contact opens, so that the driving end of the second electric control switch KA2 is powered on, the normally open contact of the second electric control switch KA2 closes immediately, and the first frequency converter VDF1 starts; the driving end of the third electric control switch KA3 loses power, and after a certain delay, the normally open contact of the third electric control switch KA3 opens, and the second frequency converter VDF2 stops.

[0054] This implementation method enables the first frequency converter VDF1 and the second frequency converter VDF2 to drive the two circulation pumps to run for a period of time simultaneously when switching, avoiding the problem of insufficient water flow power in the pipeline during switching.

[0055] In a possible implementation manner, the thermal power plant heat network circulation pump control system further includes a first cumulative timer and a second cumulative timer;

[0056] The start output end of the first frequency converter VDF1 is connected to one end of the first cumulative timer JSQ1;

[0057] The start output end of the second frequency converter VDF2 is connected to one end of the second cumulative timer JSQ2;

[0058] The second end of the third power supply is connected to the other end of the first cumulative timer JSQ1 and the other end of the second cumulative timer JSQ2.

[0059] In this implementation method, as Figure 5As shown, the first cumulative timer JSQ1 and the second cumulative timer JSQ2 can be selected from SUHED's H7ET cumulative timer. When the first frequency converter VDF1 is started, the first cumulative timer JSQ1 starts to count. When the first frequency converter VDF1 is stopped, the first cumulative timer JSQ1 saves the current cumulative time and stops counting. The working principle of the second cumulative timer JSQ2 is the same as the above process, which will not be repeated here.

[0060] This embodiment can clearly record the operating time of the two frequency converters, making it convenient for users to formulate targeted maintenance plans based on the accumulated operating time, so as to improve the maintenance level of the frequency converters and indirectly increase the service life of each frequency converter and each circulating pump.

[0061] In a possible implementation, the thermal power plant heat network circulation pump control system further includes a first temperature sensor T1 and a second temperature sensor T2;

[0062] The first temperature sensor T1 is arranged on the first frequency converter VDF1 and is used to monitor the temperature of the first frequency converter VDF1;

[0063] The second temperature sensor T2 is disposed on the second inverter VDF2 and is used for monitoring the temperature of the second inverter VDF2.

[0064] In this embodiment, the temperature sensor is used to monitor the operating temperature of the corresponding inverter in real time.

[0065] In a possible implementation, the thermal power plant heat network circulation pump control system further includes a fourth power supply, a first temperature control switch, a second temperature control switch and a fourth electric control switch KAT;

[0066] like Figure 6 As shown, the first temperature sensor T1 is connected to the analog quantity receiving terminal AIN of the first temperature-controlled switch, and the second temperature sensor T2 is connected to the analog quantity receiving terminal AIN of the second temperature-controlled switch; the first terminal L4 of the fourth power supply is connected to the first power supply input terminal INL and the first output terminal one terminal SH1L of the first temperature-controlled switch and the first power supply input terminal INL and the first output terminal one terminal SH1L of the second temperature-controlled switch; one end of the driving end of the fourth electric-controlled switch KAT is connected to the other end SH1N of the first output terminal of the first temperature-controlled switch and the other end SH1N of the first output terminal of the second temperature-controlled switch, and the other end of the driving end of the fourth electric-controlled switch KAT, the second power supply input terminal INN of the first temperature-controlled switch and the first power supply input terminal INN of the second temperature-controlled switch are respectively connected to the second terminal N2 of the fourth power supply;

[0067] like Figure 7As shown, the other end of the normally closed contact of the first electric control switch KA1 is connected to one end of the first normally open contact KAT-1 of the fourth electric control switch KAT and one end of the first normally closed contact KAT-3 of the fourth electric control switch KAT; the other end of the normally open contact of the first electric control switch KA1 is connected to one end of the second normally open contact KAT-2 of the fourth electric control switch KAT and one end of the second normally closed contact KAT-4 of the fourth electric control switch KAT; the other end of the first normally open contact KAT-1 of the fourth electric control switch KAT and the other end of the second normally closed contact KAT-4 are connected to one end of the driving end of the second electric control switch KA2; the other end of the second normally open contact KAT-2 of the fourth electric control switch KAT and the other end of the first normally closed contact KAT-3 are connected to one end of the driving end of the third electric control switch KA3.

[0068] In this embodiment, the optional model of the temperature control switch is Bihe BF-D220A+. No matter which frequency converter has too high a temperature, the first output end of the corresponding temperature control switch is closed, so that the fourth electric control switch KAT is powered on and driven. The first normally open contact and the second normally open contact of the fourth electric control switch KAT are closed, and the first normally closed contact and the second normally closed contact are disconnected, so that the drive between the first electric control switch KA1 and the second electric control switch KA2 is reversed, stopping the running frequency converter and starting the stopped frequency converter to achieve the immediate switching of the frequency converter; and the running frequency converter with a higher temperature is stopped so that it can stop and cool down in time.

[0069] In a possible implementation manner, the fourth electric control switch KAT is a relay.

[0070] In a possible implementation manner, as Figure 6 shown, the heat network circulating pump control system of the thermal power plant further includes a first radiator and a second radiator; the first end L4 of the fourth power supply is connected to one end of the second output end of the first temperature control switch and one end of the second output end of the second temperature control switch; the other end of the second output end of the first temperature control switch is connected to one end of the first radiator, and the other end of the second output end of the second temperature control switch is connected to one end of the second radiator; the other ends of the first radiator and the second radiator are connected to the second end N4 of the fourth power supply.

[0071] As Figure 8 shown, in a possible implementation manner, a first check valve is connected to the output end of the first circulating pump; a second check valve is connected to the output end of the second circulating pump.

[0072] In the embodiment, the first check valve and the second check valve are used to prevent water from flowing back when the circulating pump is running.

[0073] In a possible implementation manner, the first electric control switch KA1 is a relay.

[0074] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A circulating pump control system for a thermal power plant heat network, comprising a first circulating pump, a second circulating pump, a first frequency converter for driving the first circulating pump, and a second frequency converter for driving the second circulating pump, characterized in that: Also includes: A timing control switch, a first electric control switch, a second electric control switch, a third electric control switch, a first power supply, a second power supply and a third power supply; The first end of the first power supply is connected to the first power supply end of the timing control switch and one end of the relay output end, the other end of the relay output end of the timing control switch is connected to one end of the driving end of the first electric control switch, and the second end is connected to the second power supply end of the timing control switch and the other end of the driving end of the first electric control switch; The first end of the second power supply is connected to one end of the normally open contact of the first electric control switch and one end of the normally closed contact of the first electric control switch; the other end of the normally open contact of the first electric control switch is connected to one end of the driving end of the second electric control switch, and the other end of the normally closed contact is connected to one end of the driving end of the third electric control switch, and the second end of the second power supply is connected to the other end of the driving end of the second electric control switch and the other end of the driving end of the third electric control switch; The first end of the third power supply is connected to one end of the normally open contact of the second electric-controlled switch and one end of the normally open contact of the third electric-controlled switch; the other end of the normally open contact of the second electric-controlled switch is connected to the start input end of the first inverter; the other end of the normally open contact of the third electric-controlled switch is connected to the start input end of the second inverter, and the second end of the third power supply is connected to the start output end of the first inverter and the start output end of the second inverter.

2. A thermal power plant heat network circulation pump control system according to claim 1, characterized in that: The timing control switch is a cycle countdown switch.

3. A thermal power plant heat network circulation pump control system according to claim 1, characterized in that: The second electronically controlled switch and the third electronically controlled switch are respectively power-off delay relays.

4. A thermal power plant heat network circulation pump control system according to claim 1, characterized in that: The thermal power plant heat network circulation pump control system also includes a first cumulative timer and a second cumulative timer; The first inverter start output terminal is connected to one end of the first cumulative timer; The second inverter start output terminal is connected to one end of the second cumulative timer; The second end of the third power supply is connected to the other end of the first cumulative timer and the other end of the second cumulative timer.

5. A thermal power plant heat network circulation pump control system according to claim 1, characterized in that: The thermal power plant heat network circulation pump control system also includes a first temperature sensor and a second temperature sensor; The first temperature sensor is arranged on the first frequency converter and is used to monitor the temperature of the first frequency converter; The second temperature sensor is arranged on the second frequency converter and is used for monitoring the temperature of the second frequency converter.

6. A thermal power plant heat network circulation pump control system according to claim 5, characterized in that: The thermal power plant heat network circulation pump control system also includes a fourth power supply, a first temperature control switch, a second temperature control switch and a fourth electric control switch; The first temperature sensor is connected to the analog quantity receiving end of the first temperature-controlled switch, and the second temperature sensor is connected to the analog quantity receiving end of the second temperature-controlled switch; the first end of the fourth power supply is connected to the first power supply input end and one end of the first output end of the first temperature-controlled switch and the first power supply input end and one end of the first output end of the second temperature-controlled switch; one end of the driving end of the fourth electric-controlled switch is connected to the other end of the first output end of the first temperature-controlled switch and the other end of the first output end of the second temperature-controlled switch, and the other end of the driving end of the fourth electric-controlled switch, the second power supply input end of the first temperature-controlled switch, and the first power supply input end of the second temperature-controlled switch are respectively connected to the second end of the fourth power supply; The other end of the normally closed contact of the first electrically-controlled switch is connected to one end of the first normally open contact of the fourth electrically-controlled switch and one end of the first normally closed contact of the fourth electrically-controlled switch; the other end of the normally open contact of the first electrically-controlled switch is connected to one end of the second normally open contact of the fourth electrically-controlled switch and one end of the second normally closed contact of the fourth electrically-controlled switch; the other end of the first normally open contact of the fourth electrically-controlled switch and the other end of the second normally closed contact of the fourth electrically-controlled switch are connected to one end of the driving end of the second electrically-controlled switch; the other end of the second normally open contact of the fourth electrically-controlled switch and the other end of the first normally closed contact of the fourth electrically-controlled switch are connected to one end of the driving end of the third electrically-controlled switch.

7. A thermal power plant heat network circulation pump control system according to claim 6, characterized in that: The fourth electronically controlled switch is a relay.

8. A thermal power plant heat network circulation pump control system according to claim 6, characterized in that: The thermal power plant heat network circulation pump control system also includes a first radiator and a second radiator; the first end of the fourth power supply is connected to one end of the second output end of the first temperature control switch and one end of the second output end of the second temperature control switch; the other end of the second output end of the first temperature control switch is connected to one end of the first radiator, and the other end of the second output end of the second temperature control switch is connected to one end of the second radiator; the other end of the first radiator and the other end of the second radiator are connected to the second end of the fourth power supply.

9. A thermal power plant heat network circulation pump control system according to claim 1, characterized in that: The output end of the first circulation pump is connected to a first check valve; The output end of the second circulation pump is connected to a second check valve.

10. A thermal power plant heat network circulation pump control system according to claim 6, characterized in that: The first electronically controlled switch is a relay.

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