A device and method for use in research on corrosion and scaling prevention of heat network circulating water system

Abstract

The present invention discloses a device and a method for using the anti-corrosion and anti-scaling research of a heat network circulating water system, the device comprising a primary network simulation loop, a secondary network simulation loop and a heat exchanger. The primary network simulation loop has a constant temperature heating device and adopts a pressure-bearing structure as a whole, which can simulate the operation of the primary network circulating water under 130°C. The primary network simulation loop and the secondary network simulation loop operate independently, and the heat of the primary network is transferred to the secondary network through a plate heat exchanger in the middle. The secondary network simulation loop has a cooling device to take the heat away from the system. Drain valves are designed above the corrosion hanging devices of the primary network and secondary network simulation loops, which can simulate the situation of air entering the system during the system shutdown process, and can study the shutdown corrosion problems of the heat network circulating water system under three conditions: full water state, half full water state and complete drainage. Carbon steel pipeline corrosion bypasses are designed in the primary network and secondary network simulation loops, which can simulate the impact of carbon steel pipeline corrosion on the water quality of circulating water.

Description

Technical Field

[0001] The invention belongs to the field of laboratory material corrosion research, and specifically relates to a device for material corrosion and scaling research in a heat network circulating water system and a use method thereof. Background Art

[0002] The city's heat network circulating water system delivers the heat generated by the thermal power plant to residents' homes step by step. Its stable operation is of great significance to ensure heating for residents in winter. The heat network circulating water system generally uses carbon steel transmission pipelines, and the heat exchanger uses stainless steel heat exchanger plates. The system has three major problems: scaling of the heat exchanger plates, pitting of the heat exchanger plates, and corrosion of the pipeline. Once the heat exchanger plates are scaled, it not only affects the heat exchange efficiency but also increases the risk of pitting and perforation of the heat exchanger plates; pitting and perforation of the heat exchanger plates lead to unstable pressure difference on both sides and cannot operate normally; corrosion of the pipeline not only reduces the thickness but also increases the content of suspended matter in the circulating water, which may cause problems such as heat exchanger blockage. In addition, the heat network system needs to be shut down for a long time during the non-heating season. If effective measures are not taken to slow down the corrosion of the pipeline during shutdown, it will affect the water quality when it is restarted. With the continuous expansion of the scale of urban centralized heating, the temperature of the primary network circulating water in the heating system has also increased. At present, the primary network temperature of some heating systems has reached 130°C, which makes the materials in the system face more severe corrosion and scaling problems. Under laboratory conditions, a simulation device was used to carry out anti-corrosion and anti-scaling research on the heat network circulating water system in order to provide guidance for on-site operation, which is of great significance for ensuring the smooth operation of the system.

[0003] Conventional corrosion test simulation devices cannot simulate the heat exchange process of the heating network system step by step, and it is difficult to simulate the scaling process of the heat exchange plate in the field environment. At present, the maximum temperature of the circulating water in the heating network has reached 130°C, so the test simulation device must have a pressure-bearing design. Conventional corrosion test simulation devices do not consider the impact of suspended matter generated by carbon steel pipeline corrosion on the water quality of the heating network circulating water. Conventional corrosion test devices do not have special designs for decommissioning corrosion research, and cannot carry out related research work on system decommissioning corrosion. Due to these reasons, the simulation device for material anti-corrosion and anti-scaling research in the heating network circulating water system is still blank. Summary of the invention

[0004] In order to solve the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a simulation device for the research on material corrosion and scaling of the heat network circulating water system. The device can simulate the heat exchange process between the primary network and the secondary network under the condition of 130°C; it can study the scaling of the heat exchange plate, pitting of the heat exchange plate and pipeline corrosion problems, consider the influence of suspended matter generated by carbon steel corrosion on the water quality of the heat network circulating water, and can conduct research on material decommissioning corrosion.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solution:

[0006] A device for studying the corrosion and scaling prevention of a heat network circulating water system, comprising a primary network simulation loop, a secondary network simulation loop and a heat exchanger therebetween; the primary network simulation loop comprises a primary network water storage tank 6, a primary network circulating water pump 7, a primary network circulating water inlet valve 8, a primary network pre-heat exchange corrosion sample hanging device 9, a plate heat exchanger 10 hot water inlet, a plate heat exchanger 10 hot water outlet, a primary network post-heat exchange corrosion sample hanging device 13 and a primary network circulating water return valve 14, the primary network water storage tank 6 is provided with a primary network water storage tank filling valve 1 ... circulating water return valve 14, a primary network circulating water return valve 15, a primary network circulating water return valve 16, a primary network circulating water return valve 17, a primary network circulating water return valve 18, a primary network circulating water return valve 19, a primary network circulating water return valve 11, a primary network circulating water return valve 12, a primary network circulating water return valve 13, a primary network circulating water return valve 14, a primary network circulating water return valve 15, a primary network circulating water return valve 16, a primary network circulating water return valve 17, a primary network circulating water return valve 18, a primary network circulating water return valve 19, a primary network circulating water return valve 11, a primary network circulating water return valve 12, a primary network circulating water return valve 13, a primary network circulating water return valve 14, a primary network circulating water return valve 15, a primary network A water tank thermometer 4 and a primary network water tank pressure gauge 5, a primary network water tank constant temperature heating device 3 is installed on the side of the primary network water tank 6, and a primary network water tank drain valve 2 is installed at the bottom. The circulating water is drawn from the bottom of the primary network water tank 6, and after being pressurized by the primary network circulating water pump 7, it flows through the primary network circulating water inlet valve 8 and the primary network pre-heat exchange corrosion hanging device 9 in turn, and flows into the hot water inlet of the plate heat exchanger 10. After the plate heat exchanger 10 exchanges heat with the secondary network circulating water, it flows out from the hot water outlet of the plate heat exchanger 10, passes through the primary network post-heat exchange corrosion hanging device 13, the primary network circulating water The water returns to the primary network water storage tank 6 after the water return valve 14; a sampling bypass is provided between the primary network circulating water pump 7 and the primary network circulating water inlet valve 8, and a primary network sampling valve 19, a primary network sampling cooling device 20 and a primary network sampling port 21 are provided on the sampling bypass; a primary network pre-heat exchange temperature probe 11 is installed between the primary network pre-heat exchange corrosion sample hanging device 9 and the hot water inlet of the plate heat exchanger 10, and a primary network post-heat exchange temperature probe 12 is installed between the hot water outlet of the plate heat exchanger 10 and the primary network post-heat exchange corrosion sample hanging device 13; the primary network post-heat exchange corrosion sample hanging device 13 A primary network emptying valve 18 is installed between the primary network circulating water return valve 14; a primary network carbon steel corrosion bypass is led out between the primary network heat exchange post-corrosion sample hanging device 13 and the primary network circulating water return valve 14 to connect to the primary network water storage tank 6, and a primary network carbon steel corrosion bypass water inlet valve 15, a primary network carbon steel pipe section 16 and a primary network carbon steel corrosion bypass water return valve 17 are arranged on the primary network carbon steel corrosion bypass, and the circulating water flows through the primary network carbon steel corrosion bypass water inlet valve 15, the primary network carbon steel pipe section 16, and the primary network carbon steel corrosion bypass water return valve 17 in sequence and then returns to the primary network water storage tank 6;

[0007] The secondary network simulation loop includes a secondary network water storage tank 22, a secondary network circulating water pump 29, a secondary network circulating water inlet valve 30, a secondary network circulating water flowmeter 31, a secondary network pre-heat exchange corrosion sample hanging device 32, a plate heat exchanger 10 cold water inlet, a plate heat exchanger 10 cold water outlet, a secondary network post-heat exchange corrosion sample hanging device 33 and a secondary network circulating water return valve 36, which are sequentially connected to form a loop. A secondary network water storage tank 22 is provided with a secondary network water storage tank filling valve 23 and a secondary network water storage tank thermometer 25 at the top, a secondary network water storage tank 22 is provided with a secondary network water storage tank drain valve 24 at the bottom, and a cooling device is provided inside the secondary network water storage tank 22. The cooling device includes a cooling device according to the cooling device. The secondary network cooling water ring pipe inlet valve 26, the secondary network cooling water ring pipe 28 and the secondary network cooling water ring pipe outlet valve 27 are connected to the secondary network; the secondary network circulating water is drawn from the bottom of the secondary network water storage tank 22, and after being pressurized by the secondary network circulating water pump 29, it flows through the secondary network circulating water inlet valve 30, the secondary network circulating water flow meter 31, and the secondary network pre-heat exchange corrosion hanging device 32, and flows into the plate heat exchanger 10 from the cold water inlet of the plate heat exchanger, exchanges heat with the primary network circulating water, and flows out from the cold water outlet of the plate heat exchanger, flows through the secondary network post-heat exchange corrosion hanging device 33, the secondary network circulating water return valve 36 and then returns to the secondary network water storage tank 22; the secondary network circulating water pump 2 A flow regulating bypass is led out between 9 and the secondary network circulating water inlet valve 30, and a secondary network circulating water flow regulating bypass valve 43 is arranged on the flow regulating bypass. A part of the circulating water flows through the secondary network circulating water flow regulating bypass valve 43 and then returns to the secondary network water storage tank 22; a secondary network carbon steel corrosion bypass is led out between the secondary network circulating water inlet valve 30 and the secondary network circulating water flowmeter 31, and a secondary network carbon steel corrosion bypass inlet valve 38, a secondary network carbon steel pipe section 40 and a secondary network carbon steel corrosion bypass outlet valve 39 are arranged in sequence on the secondary network carbon steel corrosion bypass. A part of the circulating water flows through the bypass and passes through the secondary network carbon steel corrosion bypass inlet valve 38, the secondary network carbon steel corrosion bypass outlet valve 39. The secondary network carbon steel pipe section 40 and the secondary network carbon steel corrosion bypass water outlet valve 39 return to the secondary network water storage tank 22; a secondary network pre-heat exchange temperature probe 34 is installed between the secondary network pre-heat exchange corrosion sampling device 32 and the hot water inlet of the plate heat exchanger 10, and a secondary network post-heat exchange temperature probe 35 is installed between the hot water outlet of the plate heat exchanger 10 and the secondary network post-heat exchange corrosion sampling device 33; a secondary network emptying valve 37 is installed between the secondary network post-heat exchange corrosion sampling device 33 and the secondary network circulating water return valve 36; a secondary network sampling valve 41 and a secondary network sampling port 42 are arranged between the secondary network circulating water return valve 36 and the secondary network water storage tank 22.

[0008] The primary network water storage tank 6 is welded with 316L stainless steel plates and can withstand a pressure of 1 MPa.

[0009] The primary network circulating water pump 7 is a heat-resistant and pressure-resistant pump, which can operate continuously and stably under high temperature and high pressure conditions.

[0010] The method for using the device for anti-corrosion and anti-scaling research of the heat network circulating water system is as follows: first, a number of carbon steel and stainless steel test pieces of the same grade as the heat network circulating water system are hung in the corrosion sample hanging device 9 before the primary network heat exchange, the corrosion sample hanging device 13 after the primary network heat exchange, the corrosion sample hanging device 32 before the secondary network heat exchange, and the corrosion sample hanging device 33 after the secondary network heat exchange; the primary side circulating water taken from the on-site primary side pipe network is injected into the primary network water storage tank 6 through the primary network water storage tank water injection valve 1, and the secondary side circulating water taken from the on-site secondary side pipe network is injected into the secondary network water storage tank 22 through the secondary network water storage tank water injection valve 23. ; Turn on the constant temperature heating device 3 of the primary network water storage tank to heat the primary network circulating water to the target temperature, turn on the primary network circulating water pump 7 and the secondary network circulating water pump 29; adjust the secondary network circulating water flow regulating bypass valve 43 and the secondary network circulating water inlet valve 30 opening, adjust the secondary network circulating water flow to the target value; adjust the secondary network cold water ring pipe flow, observe the primary network temperature probe 11 before heat exchange, the primary network temperature probe 12 after heat exchange, the secondary network temperature probe 34 before heat exchange and the secondary network temperature probe 35 after heat exchange, to ensure that the primary and secondary side inlet and outlet water temperatures of the plate heat exchanger are close to the actual values ​​on site; in the study of circulation In the test of the influence of carbon steel corrosion products in water on the circulating water quality and scaling of heat exchange plates, the primary network carbon steel corrosion bypass water inlet valve 15 and the primary network carbon steel corrosion bypass water return valve 17 are opened to allow a part of the primary network circulating water to flow through the primary network carbon steel pipe section 16, thereby increasing the content of suspended solids in the primary network circulating water; the secondary network carbon steel corrosion bypass water inlet valve 38 and the secondary network carbon steel corrosion bypass water outlet valve 39 are opened to allow a part of the secondary network circulating water to flow through the secondary network carbon steel pipe section 40, thereby increasing the content of suspended solids in the secondary network circulating water; the primary network circulation is performed by opening the primary network sampling cooling device 20 and opening the primary network sampling valve 19. Take samples from the primary network sampling port 21 to analyze the quality of the primary network circulating water; open the secondary network sampling valve 41 to take samples from the secondary network sampling port 42 to analyze the quality of the secondary network circulating water; after the test, evaluate the material corrosion through the weight loss and macroscopic and microscopic morphology of the test pieces in the primary network corrosion sample hanging device 9 before heat exchange and the primary network corrosion sample hanging device 13 after heat exchange, as well as the secondary network corrosion sample hanging device 32 before heat exchange and the secondary network corrosion sample hanging device 33 after heat exchange, disassemble the plate heat exchanger 10, and evaluate the scaling and stainless steel pitting in the system through macroscopic observation of the surface of the plate heat exchanger plate;

[0011] When studying the corrosion of materials when they are not in use, a number of carbon steel and stainless steel test pieces with the same grade as that of the heat network circulating water system are hung in the primary network corrosion hanging device 9 before heat exchange, the primary network corrosion hanging device 13 after heat exchange, the secondary network corrosion hanging device 32 before heat exchange and the secondary network corrosion hanging device 33 after heat exchange, and the simulation device is operated. After the system runs stably, the primary network circulating water pump 7 and the secondary network circulating water pump 29 are closed, the secondary network circulating water inlet valve 30 and the primary network circulating water inlet valve 8 are closed, the secondary network drain valve 37 and the primary network circulating water inlet valve 8 are opened, and the circulating water liquid level height in the hanging device is adjusted to simulate the corrosion of materials when they are not in use under three conditions: full water state, half full water state and complete drainage of the system.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] (1) The present invention is designed with two loops, which respectively simulate the primary network and the secondary network in the heat network circulating water. Heat is transferred between the two loops through a plate heat exchanger, which can more realistically simulate the operation process of the heat network circulating water.

[0014] (2) The primary network simulation loop in the present invention adopts a pressure-bearing structure as a whole, and the circulating water pump is resistant to high temperatures and can simulate the corrosion of materials and the structure of the heat exchange surface under 130°C.

[0015] (3) In the present invention, a plate heat exchanger is used between the two circuits for heat exchange. The plate heat exchanger is easy to disassemble, so that the pitting corrosion of stainless steel and the scaling of heat exchange plates can be observed.

[0016] (4) In the present invention, drain valves are designed above the corrosion sample hanging devices of the primary and secondary network simulation loops, which can simulate the situation where air enters the heating network system during the system shutdown process, and can study the shutdown corrosion problems of the heating network circulating water system under three conditions: full water state, half full water state and complete drainage.

[0017] (5) Carbon steel corrosion bypasses are designed in both the primary and secondary network simulation loops of the present invention, which can be used for related research on the impact of carbon steel corrosion products on the circulating water quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the device of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0020] like Figure 1As shown, the present invention is a device for studying the corrosion and scale prevention of a heat network circulating water system, which is composed of a primary network simulation loop, a secondary network simulation loop and a heat exchanger therebetween; the primary network simulation loop comprises a primary network water storage tank 6, a primary network circulating water pump 7, a primary network circulating water inlet valve 8, a primary network pre-heat exchange corrosion sample hanging device 9, a plate heat exchanger 10 hot water inlet, a plate heat exchanger 10 hot water outlet, a primary network post-heat exchange corrosion sample hanging device 13 and a primary network circulating water return valve 14, which are sequentially connected to form a loop, and a primary network water storage tank water filling valve is installed on the top of the primary network water storage tank 6. 1. A thermometer 4 and a pressure gauge 5 for the primary network water storage tank. A constant temperature heating device 3 for the primary network water storage tank is installed on the side of the primary network water storage tank 6. A drain valve 2 for the primary network water storage tank is installed at the bottom. The circulating water is drawn from the bottom of the primary network water storage tank 6. After being pressurized by the primary network circulating water pump 7, it flows through the primary network circulating water inlet valve 8 and the corrosion sample hanging device 9 before the primary network heat exchange in turn, and flows into the hot water inlet of the plate heat exchanger 10. After the plate heat exchanger 10 exchanges heat with the secondary network circulating water, it flows out from the hot water outlet of the plate heat exchanger 10, passes through the corrosion sample hanging device 13 after the primary network heat exchange, and flows into the hot water inlet of the plate heat exchanger 10. The network circulating water returns to the primary network water storage tank 6 after the return valve 14; a sampling bypass is provided between the primary network circulating water pump 7 and the primary network circulating water inlet valve 8, and a primary network sampling valve 19, a primary network sampling cooling device 20 and a primary network sampling port 21 are provided on the sampling bypass; a primary network pre-heat exchange temperature probe 11 is installed between the primary network pre-heat exchange corrosion sample hanging device 9 and the hot water inlet of the plate heat exchanger 10, and a primary network post-heat exchange temperature probe 12 is installed between the hot water outlet of the plate heat exchanger 10 and the primary network post-heat exchange corrosion sample hanging device 13; the primary network post-heat exchange corrosion sample hanging device A primary network emptying valve 18 is installed between 13 and the primary network circulating water return valve 14; a primary network carbon steel corrosion bypass is led out between the primary network heat exchange post-corrosion sample hanging device 13 and the primary network circulating water return valve 14 to connect to the primary network water storage tank 6, and a primary network carbon steel corrosion bypass water inlet valve 15, a primary network carbon steel pipe section 16 and a primary network carbon steel corrosion bypass water return valve 17 are arranged on the primary network carbon steel corrosion bypass, and the circulating water flows through the primary network carbon steel corrosion bypass water inlet valve 15, the primary network carbon steel pipe section 16, and the primary network carbon steel corrosion bypass water return valve 17 in sequence and then returns to the primary network water storage tank 6;

[0021] The secondary network simulation loop includes a secondary network water storage tank 22, a secondary network circulating water pump 29, a secondary network circulating water inlet valve 30, a secondary network circulating water flowmeter 31, a secondary network pre-heat exchange corrosion sample hanging device 32, a plate heat exchanger 10 cold water inlet, a plate heat exchanger 10 cold water outlet, a secondary network post-heat exchange corrosion sample hanging device 33 and a secondary network circulating water return valve 36, which are sequentially connected to form a loop. A secondary network water storage tank 22 is provided with a secondary network water storage tank filling valve 23 and a secondary network water storage tank thermometer 25 at the top, a secondary network water storage tank 22 is provided with a secondary network water storage tank drain valve 24 at the bottom, and a cooling device is provided inside the secondary network water storage tank 22. The cooling device includes a cooling device according to the cooling device. The secondary network cooling water ring pipe inlet valve 26, the secondary network cooling water ring pipe 28 and the secondary network cooling water ring pipe outlet valve 27 are connected to the secondary network; the secondary network circulating water is drawn from the bottom of the secondary network water storage tank 22, and after being pressurized by the secondary network circulating water pump 29, it flows through the secondary network circulating water inlet valve 30, the secondary network circulating water flow meter 31, and the secondary network pre-heat exchange corrosion hanging device 32, and flows into the plate heat exchanger 10 from the cold water inlet of the plate heat exchanger, exchanges heat with the primary network circulating water, and flows out from the cold water outlet of the plate heat exchanger, flows through the secondary network post-heat exchange corrosion hanging device 33, the secondary network circulating water return valve 36 and then returns to the secondary network water storage tank 22; the secondary network circulating water pump 2 A flow regulating bypass is led out between 9 and the secondary network circulating water inlet valve 30, and a secondary network circulating water flow regulating bypass valve 43 is arranged on the flow regulating bypass. A part of the circulating water flows through the secondary network circulating water flow regulating bypass valve 43 and then returns to the secondary network water storage tank 22; a secondary network carbon steel corrosion bypass is led out between the secondary network circulating water inlet valve 30 and the secondary network circulating water flowmeter 31, and a secondary network carbon steel corrosion bypass inlet valve 38, a secondary network carbon steel pipe section 40 and a secondary network carbon steel corrosion bypass outlet valve 39 are arranged in sequence on the secondary network carbon steel corrosion bypass. A part of the circulating water flows through the bypass and passes through the secondary network carbon steel corrosion bypass inlet valve 38, the secondary network carbon steel corrosion bypass outlet valve 39. The secondary network carbon steel pipe section 40 and the secondary network carbon steel corrosion bypass water outlet valve 39 return to the secondary network water storage tank 22; a secondary network pre-heat exchange temperature probe 34 is installed between the secondary network pre-heat exchange corrosion sampling device 32 and the hot water inlet of the plate heat exchanger 10, and a secondary network post-heat exchange temperature probe 35 is installed between the hot water outlet of the plate heat exchanger 10 and the secondary network post-heat exchange corrosion sampling device 33; a secondary network emptying valve 37 is installed between the secondary network post-heat exchange corrosion sampling device 33 and the secondary network circulating water return valve 36; a secondary network sampling valve 41 and a secondary network sampling port 42 are arranged between the secondary network circulating water return valve 36 and the secondary network water storage tank 22.

[0022] As a preferred embodiment of the present invention, the primary network water storage tank 6 is welded with 316L stainless steel plates and can withstand a pressure of 1 MPa.

[0023] As a preferred embodiment of the present invention, the primary network circulating water pump 7 is a heat-resistant and pressure-resistant pump, which can operate continuously and stably under high temperature and high pressure conditions.

[0024] The method for using the device for studying the corrosion and scale prevention of the heat network circulating water system of the present invention comprises the following steps: firstly, a plurality of carbon steel and stainless steel test pieces of the same grade as the heat network circulating water system are hung in the corrosion sample hanging device 9 before the primary network heat exchange, the corrosion sample hanging device 13 after the primary network heat exchange, the corrosion sample hanging device 32 before the secondary network heat exchange, and the corrosion sample hanging device 33 after the secondary network heat exchange; the primary side circulating water taken from the on-site primary side pipe network is injected into the primary network water storage tank 6 through the primary network water storage tank water injection valve 1, and the secondary side circulating water taken from the on-site secondary side pipe network is injected into the secondary network water storage tank 22 through the secondary network water storage tank water injection valve 23. Circulating water; turn on the constant temperature heating device 3 of the primary network water tank to heat the primary network circulating water to the target temperature, turn on the primary network circulating water pump 7 and the secondary network circulating water pump 29; adjust the secondary network circulating water flow regulating bypass valve 43 and the secondary network circulating water inlet valve 30 opening, adjust the secondary network circulating water flow to the target value; adjust the secondary network cold water ring pipe flow, observe the primary network temperature probe 11 before heat exchange, the primary network temperature probe 12 after heat exchange, the secondary network temperature probe 34 before heat exchange and the secondary network temperature probe 35 after heat exchange, to ensure that the primary and secondary side inlet and outlet water temperatures of the plate heat exchanger are close to the actual values ​​on site; in the study of circulating In the test of the influence of carbon steel corrosion products in the circulating water on the circulating water quality and scaling of the heat exchanger plates, the primary network carbon steel corrosion bypass water inlet valve 15 and the primary network carbon steel corrosion bypass water return valve 17 are opened to allow a part of the primary network circulating water to flow through the primary network carbon steel pipe section 16, thereby increasing the content of suspended solids in the primary network circulating water; the secondary network carbon steel corrosion bypass water inlet valve 38 and the secondary network carbon steel corrosion bypass water outlet valve 39 are opened to allow a part of the secondary network circulating water to flow through the secondary network carbon steel pipe section 40, thereby increasing the content of suspended solids in the secondary network circulating water; the primary network circulation is performed by opening the primary network sampling cooling device 20 and opening the primary network sampling valve 19. Take samples from the primary network sampling port 21 to analyze the quality of the primary network circulating water; open the secondary network sampling valve 41 to take samples from the secondary network sampling port 42 to analyze the quality of the secondary network circulating water; after the test, evaluate the material corrosion through the weight loss and macroscopic and microscopic morphology of the test pieces in the primary network corrosion sample hanging device 9 before heat exchange and the primary network corrosion sample hanging device 13 after heat exchange, as well as the secondary network corrosion sample hanging device 32 before heat exchange and the secondary network corrosion sample hanging device 33 after heat exchange, disassemble the plate heat exchanger 10, and evaluate the scaling and stainless steel pitting in the system through macroscopic observation of the surface of the plate heat exchanger plate;

[0025] When studying the corrosion of materials when they are not in use, a number of carbon steel and stainless steel test pieces with the same grade as that of the heat network circulating water system are hung in the primary network corrosion hanging device 9 before heat exchange, the primary network corrosion hanging device 13 after heat exchange, the secondary network corrosion hanging device 32 before heat exchange and the secondary network corrosion hanging device 33 after heat exchange, and the simulation device is operated. After the system runs stably, the primary network circulating water pump 7 and the secondary network circulating water pump 29 are closed, the secondary network circulating water inlet valve 30 and the primary network circulating water inlet valve 8 are closed, the secondary network drain valve 37 and the primary network circulating water inlet valve 8 are opened, and the circulating water liquid level height in the hanging device is adjusted to simulate the corrosion of materials when they are not in use under three conditions: full water state, half full water state and complete drainage of the system.

Claims

1. A device for anti-corrosion and anti-scaling research of a heat network circulating water system, characterized in that: The invention is composed of a primary network simulation loop, a secondary network simulation loop and a heat exchanger therebetween; the primary network simulation loop comprises a primary network water storage tank (6), a primary network circulating water pump (7), a primary network circulating water inlet valve (8), a primary network pre-heat exchange corrosion sample hanging device (9), a plate heat exchanger (10) hot water inlet, a plate heat exchanger (10) hot water outlet, a primary network post-heat exchange corrosion sample hanging device (13) and a primary network circulating water return valve (14) which are sequentially connected to form a loop; a primary network water storage tank water injection valve (1), a primary network water storage tank thermometer (4) and a primary network water storage tank pressure gauge (14) are installed on the top of the primary network water storage tank (6). 5), a primary network water storage tank constant temperature heating device (3) is installed on the side of the primary network water storage tank (6), and a primary network water storage tank drain valve (2) is installed at the bottom. The circulating water is drawn from the bottom of the primary network water storage tank (6), and after being pressurized by the primary network circulating water pump (7), it flows through the primary network circulating water inlet valve (8) and the primary network pre-heat exchange corrosion hanging device (9) in sequence, and flows into the hot water inlet of the plate heat exchanger (10). After the plate heat exchanger (10) exchanges heat with the secondary network circulating water, it flows out from the hot water outlet of the plate heat exchanger (10), passes through the primary network post-heat exchange corrosion hanging device (13) and the primary network circulating water return valve (14), and then returns to the primary network. A secondary network water storage tank (6); a sampling bypass is provided between the primary network circulating water pump (7) and the primary network circulating water inlet valve (8); a primary network sampling valve (19), a primary network sampling cooling device (20) and a primary network sampling port (21) are provided on the sampling bypass; a primary network pre-heat exchange temperature probe (11) is installed between the primary network pre-heat exchange corrosion sample hanging device (9) and the hot water inlet of the plate heat exchanger (10); a primary network post-heat exchange temperature probe (12) is installed between the hot water outlet of the plate heat exchanger (10) and the primary network post-heat exchange corrosion sample hanging device (13); the primary network post-heat exchange corrosion sample hanging device (13) and the primary network A primary network drain valve (18) is installed between the circulating water return valve (14); a primary network carbon steel corrosion bypass is led out between the primary network heat exchange post-corrosion sample hanging device (13) and the primary network circulating water return valve (14) to connect to the primary network water storage tank (6); a primary network carbon steel corrosion bypass water inlet valve (15), a primary network carbon steel pipe section (16) and a primary network carbon steel corrosion bypass water return valve (17) are arranged on the primary network carbon steel corrosion bypass; the circulating water flows through the primary network carbon steel corrosion bypass water inlet valve (15), the primary network carbon steel pipe section (16) and the primary network carbon steel corrosion bypass water return valve (17) in sequence and then returns to the primary network water storage tank (6); The secondary network simulation loop comprises a secondary network water storage tank (22), a secondary network circulating water pump (29), a secondary network circulating water inlet valve (30), a secondary network circulating water flow meter (31), a secondary network pre-heat exchange corrosion sample hanging device (32), a plate heat exchanger (10) cold water inlet, a plate heat exchanger (10) cold water outlet, a secondary network post-heat exchange corrosion sample hanging device (33) and a secondary network circulating water return valve (36) which are sequentially connected to form a loop; a secondary network water storage tank (22) is provided with a secondary network water storage tank filling valve (23) and a secondary network water storage tank thermometer (25) at the top; a secondary network water storage tank (22) is provided with a secondary network water storage tank drain valve (24) at the bottom; a cooling device is provided inside the secondary network water storage tank (22); and the cooling device The device comprises a secondary network cooling water ring pipe inlet valve (26), a secondary network cooling water ring pipe (28) and a secondary network cooling water ring pipe outlet valve (27) which are connected in sequence; the secondary network circulating water is drawn from the bottom of the secondary network water storage tank (22), and after being pressurized by the secondary network circulating water pump (29), flows through the secondary network circulating water inlet valve (30), the secondary network circulating water flow meter (31), and the secondary network pre-heat exchange corrosion hanging device (32), flows into the plate heat exchanger (10) from the cold water inlet of the plate heat exchanger, exchanges heat with the primary network circulating water, flows out from the cold water outlet of the plate heat exchanger, flows through the secondary network post-heat exchange corrosion hanging device (33), the secondary network circulating water return valve (36), and then returns to the secondary network water storage tank (22); the secondary network circulating water pump A flow regulating bypass is led out between the secondary network circulating water inlet valve (29) and the secondary network circulating water inlet valve (30), and a secondary network circulating water flow regulating bypass valve (43) is arranged on the flow regulating bypass, and a part of the circulating water flows through the secondary network circulating water flow regulating bypass valve (43) and then returns to the secondary network water storage tank (22); a secondary network carbon steel corrosion bypass is led out between the secondary network circulating water inlet valve (30) and the secondary network circulating water flow meter (31), and a secondary network carbon steel corrosion bypass inlet valve (38), a secondary network carbon steel pipe section (40) and a secondary network carbon steel corrosion bypass outlet valve (39) are arranged in sequence on the secondary network carbon steel corrosion bypass, and a part of the circulating water flows through the bypass, passes through the secondary network carbon steel corrosion bypass inlet valve (38), the secondary network carbon steel pipe section (40) and the secondary network carbon steel corrosion bypass outlet valve (39), and The water returns to the secondary network water storage tank (22) after passing through the secondary network carbon steel corrosion bypass outlet valve (39); a secondary network pre-heat exchange temperature probe (34) is installed between the secondary network pre-heat exchange corrosion sampling device (32) and the hot water inlet of the plate heat exchanger (10); a secondary network post-heat exchange temperature probe (35) is installed between the hot water outlet of the plate heat exchanger (10) and the secondary network post-heat exchange corrosion sampling device (33); a secondary network emptying valve (37) is installed between the secondary network post-heat exchange corrosion sampling device (33) and the secondary network circulating water return valve (36); a secondary network sampling valve (41) and a secondary network sampling port (42) are provided between the secondary network circulating water return valve (36) and the secondary network water storage tank (22).

2. The device for anti-corrosion and anti-scaling research of a heat network circulating water system according to claim 1 is characterized in that: The primary network water storage tank (6) is welded from 316L stainless steel plates and can withstand a pressure of 1 MPa.

3. The device for anti-corrosion and anti-scaling research of a heat network circulating water system according to claim 1 is characterized in that: The primary network circulating water pump (7) is a heat-resistant and pressure-resistant pump, and can operate continuously and stably under high temperature and high pressure conditions.

4. The method for using the device for studying corrosion and scaling prevention of a heat network circulating water system according to any one of claims 1 to 3, characterized in that: First, a number of carbon steel and stainless steel test pieces of the same grade as the heat network circulating water system are hung in the corrosion sample hanging device (9) before the primary network heat exchange, the corrosion sample hanging device (13) after the primary network heat exchange, the corrosion sample hanging device (32) before the secondary network heat exchange, and the corrosion sample hanging device (33) after the secondary network heat exchange; the primary side circulating water taken from the on-site primary side pipe network is injected into the primary network water storage tank (6) through the primary network water storage tank water filling valve (1), and the secondary side circulating water taken from the on-site secondary side pipe network is injected into the secondary network water storage tank (22) through the secondary network water storage tank water filling valve (23); the primary network water storage tank constant temperature heating device (3) is turned on to heat the primary network water storage tank; The secondary network circulating water is heated to the target temperature, and the primary network circulating water pump (7) and the secondary network circulating water pump (29) are turned on; the secondary network circulating water flow regulating bypass valve (43) and the secondary network circulating water inlet valve (30) are adjusted to adjust the secondary network circulating water flow to the target value; the secondary network cold water ring pipe flow is adjusted, and the primary network temperature probe (11) before heat exchange, the primary network temperature probe (12) after heat exchange, the secondary network temperature probe (34) before heat exchange and the secondary network temperature probe (35) after heat exchange are observed to ensure that the primary and secondary side inlet and outlet water temperatures of the plate heat exchanger are close to the actual values ​​on site; in the study of the effect of carbon steel corrosion products in circulating water on circulating water In the test of the influence of the quality and the scaling of the heat exchange plate, the primary network carbon steel corrosion bypass water inlet valve (15) and the primary network carbon steel corrosion bypass water return valve (17) are opened to allow a part of the primary network circulating water to flow through the primary network carbon steel pipe section (16), thereby increasing the content of suspended solids in the primary network circulating water; the secondary network carbon steel corrosion bypass water inlet valve (38) and the secondary network carbon steel corrosion bypass water outlet valve (39) are opened to allow a part of the secondary network circulating water to flow through the secondary network carbon steel pipe section (40), thereby increasing the content of suspended solids in the secondary network circulating water; the primary network circulation is carried out by opening the primary network sampling cooling device (20), opening the primary network sampling valve (19), and sampling from the primary network sampling port (21) sampling and analyzing the quality of the primary network circulating water; the secondary network sampling valve (41) is opened for the secondary network circulating water to sample from the secondary network sampling port (42) and analyze the quality of the secondary network circulating water; after the test, the material corrosion condition is evaluated by the weight loss and macroscopic and microscopic morphology of the test pieces in the primary network corrosion sample hanging device (9) before heat exchange and the primary network corrosion sample hanging device (13) after heat exchange, as well as the secondary network corrosion sample hanging device (32) before heat exchange and the secondary network corrosion sample hanging device (33) after heat exchange, and the plate heat exchanger (10) is disassembled, and the scaling condition and stainless steel pitting condition in the system are evaluated by macroscopic observation of the surface of the plate heat exchanger plate; When studying the corrosion of materials when they are not in use, a number of carbon steel and stainless steel test pieces of the same grade as that of the heat network circulating water system are hung in the corrosion sample hanging device (9) before the primary network heat exchange, the corrosion sample hanging device (13) after the primary network heat exchange, the corrosion sample hanging device (32) before the secondary network heat exchange, and the corrosion sample hanging device (33) after the secondary network heat exchange. The simulation device is operated. After the system runs stably, the primary network circulating water pump (7) and the secondary network circulating water pump (29) are turned off, the secondary network circulating water inlet valve (30) and the primary network circulating water inlet valve (8) are turned off, the secondary network emptying valve (37) and the primary network circulating water inlet valve (8) are opened, and the circulating water liquid level in the hanging device is adjusted to simulate the corrosion of materials when they are not in use under three conditions: full water state, half full water state, and complete drainage of the system.

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