Cooling heat exchanger, heat medium water heat exchange system and leakage detection method of the system

Abstract

The invention discloses a cooling heat exchanger, a heat medium water heat exchange system and a leakage detection method of the system, wherein the cooling heat exchanger comprises a plurality of large heat exchange components arranged in parallel in a cooling box, each large heat exchange component comprises a water inlet main pipe and a water outlet main pipe, the water outlet main pipe is provided with a water outlet main valve, the water inlet main pipe is provided with a water inlet main valve, each large heat exchange component also comprises at least two medium heat exchange components arranged in series, each medium heat exchange component is composed of a plurality of small heat exchange components arranged in parallel, the heat medium water heat exchange system comprises a cooling heat exchanger, the cooling heat exchanger is connected with an electric precipitator, an induced draft fan, a desulfurization absorption tower and a heating heat exchanger in sequence, the cooling heat exchanger and the heating heat exchanger are connected through a first connecting pipe and a second connecting pipe, the second connecting pipe is also connected with an expansion box through a pipeline, and the expansion box is located at the highest point. The heat medium water heat exchange system of the invention is convenient for detecting and determining the leakage of heat medium water, and can quickly find the leakage point and isolate the minimum unit.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal power generation, and in particular relates to a cooling heat exchanger, a heat medium water heat exchange system and a leakage detection method of the system. Background Art

[0002] The heat exchange system composed of closed liquid heat medium, often called LGGH system, has important applications in thermal power plants. The good operation of LGGH is one of the main factors that determine the maximum output of the generator set. Figure 1 As shown, the system transfers the heat of relatively high-temperature flue gas to relatively low-temperature flue gas to meet the working requirements of electrostatic precipitator and the environmental protection requirements of chimney emissions. However, part of the heat of the flue gas is inevitably carried away by the spray slurry of the desulfurization absorption tower, causing the temperature to drop. Chimney corrosion protection and flue gas lifting require a higher temperature.

[0003] In the prior art, LGGH cooling heat exchangers generally work in high dust areas, with smoke concentrations reaching 20-30g / Nm 3 Under the scouring of smoke particles, some parts of the heat exchange tubes are damaged, causing heat medium water leakage, local dust accumulation and agglomeration, reducing the flue gas flow area, accelerating the blowing and grinding of the heat exchanger tubes, and leading to a vicious cycle of increasing leakage points. 2 Concentration up to 2g / Nm 3 , which accelerates the agglomeration of dust and makes it hard to remove. 2 High concentration also accelerates metal corrosion. In actual production, when the LGGH system fails to detect leakage in time, resulting in untimely treatment, or the search process is complicated and time-consuming, the dust removal efficiency is reduced and the power consumption of the induced draft fan is increased, which not only affects environmental protection but also increases the power consumption rate of the plant. In severe cases, the electric field of the electrostatic precipitator is short-circuited, the dust removal device is completely tripped, and the unit is forced to stop, resulting in increased insecurity of the power grid, and serious economic assessments. In the prior art, means for detecting leakage include high-temperature humidity sensors, infrared imaging sensors, etc. For example, patent CN105987789A arranges a high-temperature humidity sensor with a comb-shaped detection surface at the bottom of the front and rear sides of the flue gas, and uses the humidity difference to judge the leakage. Patent CN110608846A uses single-point infrared imaging technology to detect the temperature field change of the heat exchange tube to find the leakage. However, the detection sensor is often arranged in a high-temperature, high-dust, and high-flow rate flue, or in acidic effluent, where the environment is poor and it also needs to face problems such as wear, high temperature, and corrosion. In the process of detecting leakage, there may also be problems such as inability to detect continuously, poor detection accuracy, high cost, and high maintenance.

[0004] Therefore, there is an urgent need for a cooling heat exchanger, a heat medium water heat exchange system and a leakage detection method for the system that can solve the above problems. Summary of the invention

[0005] In view of the above-mentioned technical problems, the present invention provides a cooling heat exchanger and a heat medium water heat exchange system that are easy to detect leakage, and a leakage detection method of the system.

[0006] The technical solution of the present invention is:

[0007] A cooling heat exchanger, comprising a plurality of large heat exchange components arranged in parallel in a cooling box, each of the large heat exchange components comprising a water inlet main pipe and a water outlet main pipe, the water outlet main pipe is provided with a water outlet main valve, the water inlet main pipe is provided with a water inlet main valve, each of the large heat exchange components further comprises at least two medium heat exchange components arranged in series, and each of the medium heat exchange components is composed of a plurality of small heat exchange components arranged in parallel.

[0008] Preferably, each of the small heat exchange components comprises a heat medium water heat exchange tube, one end of the heat medium water heat exchange tube is provided with a water inlet valve, and the other end of the heat medium water heat exchange tube is provided with a water outlet valve.

[0009] Preferably, the outlet of the water inlet valve of each small heat exchange component is connected to a first drain pipe, on which a first drain valve is provided; the inlet of the water outlet valve of each small heat exchange component is connected to a second drain pipe, on which a second drain valve is provided.

[0010] Preferably, the first drain pipe and the second drain pipe are both connected to a main drain pipe.

[0011] A heat medium water heat exchange system comprises a heating heat exchanger and the above-mentioned cooling heat exchanger, the cooling heat exchanger is provided with a heat medium water low temperature inlet and a heat medium water high temperature outlet, the heating heat exchanger is provided with a heat medium water high temperature inlet and a heat medium water low temperature outlet, the heat medium water high temperature outlet and the heat medium water high temperature inlet are connected through a first connecting pipe, the heat medium water low temperature inlet and the heat medium water low temperature outlet are connected through a second connecting pipe, a heat medium water circulation pump and a water replenishment valve are provided on the second connecting pipe, the second connecting pipe is also connected to an expansion tank through a pipeline, the expansion tank is located at the highest point, and an air release valve is provided on the top of the expansion tank.

[0012] Preferably, the cooling heat exchanger is connected to the electrostatic precipitator, the induced draft fan, the desulfurization absorption tower and the heating heat exchanger in sequence. After the boiler flue gas is cooled by the cooling heat exchanger, it flows through the electrostatic precipitator, the induced draft fan and the desulfurization absorption tower in sequence, and then the clean flue gas is discharged through the heating heat exchanger.

[0013] Preferably, the expansion tank is provided with a liquid level transmitter, the second connecting pipe is provided with a temperature sensor and a pressure transmitter, and the liquid level transmitter, the temperature sensor and the pressure transmitter are all connected to a controller.

[0014] Preferably, the water inlet main pipe of the large heat exchange component is connected to the low-temperature inlet of the heat medium water, and the water outlet main pipe of the large heat exchange component is connected to the high-temperature outlet of the heat medium water.

[0015] A method for detecting leakage of a heat medium water heat exchange system comprises the following steps:

[0016] S1. Open the vent valve, fill the system consisting of the cooling heat exchanger, the heating heat exchanger, the first connecting pipe and the second connecting pipe with heat medium water and exhaust the air until the air with a volume of 1 / 7-1 / 6 of the volume of the expansion tank is left in the expansion tank at the highest point, then stop filling with heat medium water and close the vent valve;

[0017] S2, start the heat medium water circulation pump to establish the normal circulation flow required for heat exchange;

[0018] S3. After the generator set is running, the temperature of the heat medium water increases, and the temperature and pressure of the expansion tank will also increase to a certain extent. As the load changes, the closed expansion tank will suppress the change of the liquid level. When the heat medium water leaks, the pressure of the expansion tank will drop. When the pressure of the expansion tank is equal to the saturation pressure of the temperature in the expansion tank, a saturated steam and air mixture will form at the top of the expansion tank, and the liquid level will begin to drop. If the liquid level in the expansion tank is as low as the first liquid level, open the water supply valve. If the liquid level in the expansion tank rises to the second liquid level, close the water supply valve.

[0019] S4, establishing a liquid level temperature compensation model for the actual liquid level of the expansion tank and the standard liquid level of the expansion tank;

[0020] S5. Excluding the influence of other factors, when the change of the actual liquid level of the expansion tank is only related to the leakage of the heat medium water, first convert the actual liquid level change rate of the expansion tank into the standard liquid level change rate of the expansion tank according to the liquid level temperature compensation model, and then calculate the heat medium water leakage. The heat medium water leakage is the product of the standard liquid level change rate of the expansion tank and the cross-sectional area inside the expansion tank.

[0021] Preferably, the first liquid level is 40% of the total liquid level in the expansion tank, and the second liquid level is 80% of the total liquid level in the expansion tank.

[0022] The beneficial effects of the present invention are:

[0023] (1) In actual use, the heat exchange tubes of the cooling heat exchanger are more likely to leak in the flue than the heating heat exchanger. The present invention improves the cooling heat exchanger. The cooling heat exchanger includes a plurality of large heat exchange components arranged in parallel, each of which also includes two medium heat exchange components arranged in series, and each of which is composed of a plurality of small heat exchange components arranged in parallel. This helps to quickly find the large heat exchange component with a leak, and then find the small heat exchange component with a leak in the large heat exchange component, and then isolate the small heat exchange component by closing the corresponding water inlet valve and water outlet valve. This will not only prevent the leakage from expanding and avoid dust accumulation and agglomeration, but also minimize the impact on the heat exchange effect as much as possible, thereby reducing the impact on the maximum output of the generator set, and at the same time, it can also prevent the electric field from short-circuiting and tripping, and ensure that the environmental protection emissions are qualified during the maintenance period;

[0024] (2) The present invention provides a heat medium water heat exchange system with an expansion tank, which is convenient for detecting and determining the leakage amount of the heat medium water. The heat medium water heat exchange system includes a cooling heat exchanger. If the leakage point is in the cooling heat exchanger, it is convenient to quickly find the leakage point in the cooling heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0026] Figure 1 It is a structural schematic diagram of a heat exchange system in the prior art;

[0027] Figure 2 It is a structural schematic diagram of the heat exchange system of the present invention;

[0028] Figure 3 It is a structural schematic diagram of the large heat exchange component of the present invention.

[0029] The markings in the figure are: 1. Cooling heat exchanger; 1.1. Low-temperature inlet of heat medium water; 1.2. High-temperature outlet of heat medium water; 1.3. Main water outlet valve; 1.4. Main water inlet valve; 1.5. Heat exchange tube of heat medium water; 1.6. Inlet valve; 1.7. Outlet valve; 1.8. First drain valve; 1.9. Second drain valve; 1.10. Main drain pipe; 2. Electrostatic precipitator; 3. Induced draft fan; 4. Desulfurization absorption tower; 5. Heating heat exchanger; 5.1. High-temperature inlet of heat medium water; 5.2. Low-temperature outlet of heat medium water; 6. First connecting pipe; 7. Second connecting pipe; 8. Heat medium water circulation pump; 9. Make-up valve; 10. Expansion tank; 11. Vent valve; 12. Level transmitter; 13. Temperature sensor; 14. Pressure transmitter; 15. Controller. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0031] like Figure 2 and Figure 3 As shown, a heat medium water heat exchange system includes a cooling heat exchanger 1, which is connected to an electrostatic precipitator 2, an induced draft fan 3, a desulfurization absorption tower 4 and a heating heat exchanger 5 in sequence. After the boiler flue gas is cooled by the cooling heat exchanger 1, it flows through the electrostatic precipitator 2, the induced draft fan 3 and the desulfurization absorption tower 4 in sequence, and then the clean flue gas is discharged through the heating heat exchanger 5. The cooling heat exchanger 1 is provided with a heat medium water low temperature inlet 1.1 and a heat medium water high temperature outlet 1.2, and the heating heat exchanger 5 is provided with a heat medium water high temperature inlet 5.1 and a heat medium water low temperature outlet 5.2. The heat medium water high temperature outlet 1.2 and the heat medium water high temperature inlet 5.1 are connected through a first connecting pipe 6, and the heat medium water low temperature inlet 1.1 and the heat medium water low temperature outlet 5.2 are connected through a second connecting pipe 7. A heat medium water circulation pump 8 and a water supply valve 9 are provided on the second connecting pipe 7. The second connecting pipe 7 is also connected to an expansion tank 10 through a pipeline. The expansion tank 10 is located at the highest point, and an air release valve 11 is provided on the top of the expansion tank 10.

[0032] Among them, the cooling heat exchanger 1 includes a plurality of large heat exchange components arranged in parallel in the cooling box, each large heat exchange component includes a water inlet main pipe and a water outlet main pipe, the water outlet main pipe is provided with a water outlet main valve 1.3, the water inlet main pipe is provided with a water inlet main valve 1.4, the water inlet main pipe of the large heat exchange component is connected to the low-temperature inlet 1.1 of the heat medium water, and the water outlet main pipe of the large heat exchange component is connected to the high-temperature outlet 1.2 of the heat medium water. Each large heat exchange assembly also includes at least two medium heat exchange assemblies arranged in series, and each medium heat exchange assembly is composed of a plurality of small heat exchange assemblies arranged in parallel. The heat medium water flows into each small heat exchange assembly in the large heat exchange assembly through the water inlet main pipe, and then flows out from the water outlet main pipe. Each small heat exchange assembly includes a heat medium water heat exchange pipe 1.5, one end of the heat medium water heat exchange pipe 1.5 is provided with a water inlet valve 1.6, and the other end of the heat medium water heat exchange pipe 1.5 is provided with a water outlet valve 1.7. In actual use, the heat exchange pipe of the cooling heat exchanger 1 is arranged in the flue compared with the heating heat exchanger 5. It is more likely to leak. By improving the cooling heat exchanger 1, it is possible to quickly find the large heat exchange component with a leak, and then find the small heat exchange component with a leak in the large heat exchange component, and then isolate the small heat exchange component by closing the corresponding water inlet valve 1.6 and water outlet valve 1.7. This will not only prevent the leakage from expanding and avoid dust accumulation and agglomeration, but also minimize the impact on the heat exchange effect as much as possible, thereby reducing the impact on the maximum output of the generator set, and at the same time, it can also prevent the electric field short circuit tripping, and ensure that the environmental emission is qualified during the maintenance cycle. In addition, the outlet of the water inlet valve 1.6 of each small heat exchange component is connected to a first drain pipe, and the first drain pipe is provided with a first drain valve 1.8. The inlet of the water outlet valve 1.7 of each small heat exchange component is connected to a second drain pipe, and the second drain pipe is provided with a second drain valve 1.9. The first drain pipe and the second drain pipe can be combined into a main drain pipe 1.10 to facilitate the discharge of heat medium water.

[0033] The expansion tank 10 is provided with a liquid level transmitter 12, and the second connecting pipe 7 is provided with a temperature sensor 13 and a pressure transmitter 14. The liquid level transmitter 12, the temperature sensor 13 and the pressure transmitter 14 are all connected to the controller 15. The liquid level transmitter 12 is used to monitor the liquid level changes in the expansion tank 10 and feed the results back to the controller 15. The temperature sensor 13 is used to monitor the temperature changes of the heat medium water in the second connecting pipe 7 and feed the results back to the controller 15. The pressure transmitter 14 is used to monitor the pressure changes in the second connecting pipe 7 and feed the structure back to the controller 15.

[0034] The present invention also provides a method for detecting leakage of a heat medium water heat exchange system, comprising the following steps:

[0035] S1. Open the vent valve 11, fill the system consisting of the cooling heat exchanger 1, the heating heat exchanger 5, the first connecting pipe 6 and the second connecting pipe 7 with heat medium water and exhaust the air until the expansion tank 10 at the highest point has air with a volume of 1 / 7-1 / 6 of the tank volume, then stop filling with heat medium water and close the vent valve 11. Note that the water supply valve 9 should be closed tightly and the internal leakage flow should be small enough to prevent interference with the liquid level change;

[0036] S2. Turn on the heat medium water circulation pump 8 to establish the normal circulation flow required for heat exchange. At this time, pay attention to the inlet pressure of the heat medium water circulation pump 8 to prevent the heat medium water in the system from being vaporized at low pressure at a high altitude, causing two-phase flow in the pipeline and vibration, thus damaging the equipment.

[0037] S3. After the generator set is running, the temperature of the heat medium water rises, and the temperature and pressure of the expansion tank 10 will also rise to a certain extent. As the load changes, the closed expansion tank 10 will suppress the change of the liquid level; when the heat medium water leaks, the pressure of the expansion tank 10 will drop. When the pressure of the expansion tank 10 is equal to the saturation pressure of the temperature in the expansion tank 10, a saturated steam and air mixture will form at the top of the expansion tank 10, and the liquid level begins to drop. If the liquid level of the expansion tank 10 is as low as the first liquid level, the first liquid level is 40% of the total liquid level of the expansion tank 10, and the water supply valve 9 is opened. If the liquid level of the expansion tank 10 rises to the second liquid level, the second liquid level is 80% of the total liquid level of the expansion tank 10, and the water supply valve 9 is closed;

[0038] S4, establishing a liquid level temperature compensation model for the actual liquid level of the expansion tank and the standard liquid level of the expansion tank;

[0039] S5. Excluding the influence of other factors, when the change of the actual liquid level of the expansion tank is only related to the leakage of the heat medium water, if the leakage is large and the liquid level drops quickly, first convert the actual liquid level change rate of the expansion tank into the standard liquid level change rate of the expansion tank according to the liquid level temperature compensation model, and then calculate the leakage of the heat medium water. The leakage of the heat medium water is the product of the standard liquid level change rate of the expansion tank and the cross-sectional area of ​​the expansion tank. The specific calculation formula is: v = dL×A×10 -6 , v (L / min) is the leakage of heat medium water, dL (mm / min) is the rate of change of standard liquid level in the expansion tank, A (mm 2 ) is the cross-sectional area inside the expansion tank.

[0040] After the new installation or overhaul, the heat medium water heat exchange system ensures that there is no leakage in a short time. At this time, the actual liquid level of the expansion tank and the heat medium water circulating water flow, the inlet water temperature of the cooler, the inlet water temperature of the warmer, and the outlet water temperature of the warmer, which are related factors affecting the liquid level, are recorded to establish a liquid level temperature compensation model. Because the equipment installation and the actual situation are relatively complicated, the functional relationship between the standard liquid level of the expansion tank and these parameters is obtained through the extraction and analysis of the operation data. After the test of time, the final liquid level temperature compensation model is corrected and determined. In the actual process, the water temperature of the heat medium water in the heat medium water heat exchange system mainly rises and falls with the unit load, fluctuating by about plus or minus 2°C, which has little effect on the liquid level of the expansion tank 10 of the system. The relationship between the key point temperature and the liquid level change is found through historical data, and then the standard liquid level of the expansion tank is obtained through temperature compensation, and its rate of decline is proportional to the leakage flow. The present invention reduces the influence of the unit load change on the liquid level of the expansion tank 10, compensates the detected liquid level for the system temperature, reduces the interference of the system temperature on the liquid level signal, and obtains a more stable liquid level signal.

[0041] The heat medium water heat exchange system of the present invention includes a cooling heat exchanger 1, and the cooling heat exchanger 1 has been improved. The cooling heat exchanger 1 includes a plurality of large heat exchange components arranged in parallel, and each large heat exchange component also includes two heat exchange groups arranged in series, and each heat exchange group is composed of a plurality of small heat exchange components arranged in parallel. In actual use, if the leakage point is confirmed to be inside the cooling heat exchanger 1 through inspection and maintenance, the specific leakage point can be quickly found, and by closing the corresponding valve, it is ensured that the normal use of the cooling heat exchanger 1 is still guaranteed without expanding the leakage. Assuming that the maximum leakage of heat medium water in each large heat exchange component is 2L / min, when it is determined that the leakage occurs only in the cooling heat exchanger 1, the leakage of heat medium water in the heat medium water heat exchange system v 0 If the leakage reaches or exceeds -2L / min, it is necessary to check online to determine the leakage amount of the leak point, and then isolate the leak module. The specific use process is as follows:

[0042] (1) Determine the leaking large heat exchange component: Close the water inlet main valve 1.4 and the water outlet main valve 1.3 to isolate the large heat exchange component and observe for 5-10 minutes. If the heat medium water leakage decreases and gradually decreases to the basic background value (such as -0.2 L / min), it is determined that the large heat exchange component is leaking; determine v 0 Is it within the tolerance range of the large heat exchange component with leakage? 0 is greater than the tolerance range, that is, v 0 If it is negative and the absolute value is greater than 2L / min, proceed to the next step;

[0043] (2) Determine the leaking heat exchange component: Open the main water inlet valve 1.4 and the main water outlet valve 1.3 of the leaking large heat exchange component to put it into operation. At this time, the heat medium water leakage is restored to v 0 , and then isolate the small heat exchange components in turn, that is, close the corresponding water inlet valve 1.6 and water outlet valve 1.7, and observe for 5-10 minutes. The leakage of heat medium water at this time is the leakage of the small heat exchange component. If the leakage of heat medium water does not decrease significantly, it can be reopened and the next small heat exchange component can be isolated. When a small heat exchange component with a large leakage is found, the small heat exchange component will be isolated, and then continue to monitor and isolate the small heat exchange component until the total leakage of heat medium water in the heat medium water heat exchange system drops to an allowable range.

[0044] The present invention observes the difference in leakage before and after isolation by different isolation ranges, thereby obtaining the leakage situation of the isolated module, and then decides whether to isolate it based on the minimum allowable leakage flow of each heat exchange module, the leakage amount and the heat exchange situation, and makes the best decision, thereby completing the online search and isolation operation of heat exchange components with large leaks and heat exchange components with small leaks, and maximizing the role of the heat exchanger in the operation of the flue gas environmental protection facilities.

[0045] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A heat medium water heat exchange system, It is characterized in that The heat medium water heat exchange system can be operated to detect and determine the leakage of the heat medium water; The heat medium water heat exchange system comprises a heating heat exchanger and a cooling heat exchanger, the cooling heat exchanger is provided with a heat medium water low temperature inlet and a heat medium water high temperature outlet, the heating heat exchanger is provided with a heat medium water high temperature inlet and a heat medium water low temperature outlet, the heat medium water high temperature outlet and the heat medium water high temperature inlet are connected through a first connecting pipe, the heat medium water low temperature inlet and the heat medium water low temperature outlet are connected through a second connecting pipe, a heat medium water circulation pump and a water supply valve are provided on the second connecting pipe, the second connecting pipe is also connected to an expansion tank through a pipeline, the expansion tank is located at the highest point, and a vent valve is provided on the top of the expansion tank; The cooling heat exchanger includes a plurality of large heat exchange components arranged in parallel in the cooling box, each of the large heat exchange components includes a water inlet main pipe and a water outlet main pipe, the water outlet main pipe is provided with a water outlet main valve, the water inlet main pipe is provided with a water inlet main valve, each of the large heat exchange components also includes at least two medium heat exchange components arranged in series, and each of the medium heat exchange components is composed of a plurality of small heat exchange components arranged in parallel.

2. The heat medium water heat exchange system according to claim 1, It is characterized in that Each of the small heat exchange components comprises a heat medium water heat exchange tube, one end of the heat medium water heat exchange tube is provided with a water inlet valve, and the other end of the heat medium water heat exchange tube is provided with a water outlet valve.

3. The heat medium water heat exchange system according to claim 2, It is characterized in that The outlet of the water inlet valve of each small heat exchange component is connected to a first drain pipe, on which a first drain valve is provided; the inlet of the water outlet valve of each small heat exchange component is connected to a second drain pipe, on which a second drain valve is provided.

4. The heat medium water heat exchange system according to claim 3, It is characterized in that The first drain pipe and the second drain pipe are both connected to the main drain pipe.

5. The heat medium water heat exchange system according to claim 1, It is characterized in that The cooling heat exchanger is connected to the electrostatic precipitator, the induced draft fan, the desulfurization absorption tower and the heating heat exchanger in sequence. After the boiler flue gas is cooled by the cooling heat exchanger, it flows through the electrostatic precipitator, the induced draft fan and the desulfurization absorption tower in sequence, and then the clean flue gas is discharged through the heating heat exchanger.

6. The heat medium water heat exchange system according to claim 1, It is characterized in that The expansion tank is provided with a liquid level transmitter, the second connecting pipe is provided with a temperature sensor and a pressure transmitter, and the liquid level transmitter, the temperature sensor and the pressure transmitter are all connected to a controller.

7. The heat medium water heat exchange system according to claim 1, It is characterized in that The water inlet main pipe of the large heat exchange component is connected to the low-temperature inlet of the heat medium water, and the water outlet main pipe of the large heat exchange component is connected to the high-temperature outlet of the heat medium water.

8. A method for detecting leakage of a heat medium water heat exchange system according to claim 1, It is characterized in that The steps include: S1. Open the vent valve, fill the system consisting of the cooling heat exchanger, the heating heat exchanger, the first connecting pipe and the second connecting pipe with heat medium water and exhaust the air until the air with a volume of 1 / 7-1 / 6 of the volume of the expansion tank is left in the expansion tank at the highest point, then stop filling with heat medium water and close the vent valve; S2, start the heat medium water circulation pump to establish the normal circulation flow required for heat exchange; S3. After the generator set is running, the temperature of the heat medium water increases, and the temperature and pressure of the expansion tank will also increase to a certain extent. As the load changes, the closed expansion tank will suppress the change of the liquid level. When the heat medium water leaks, the pressure of the expansion tank will drop. When the pressure of the expansion tank is equal to the saturation pressure of the temperature in the expansion tank, a saturated steam and air mixture will form at the top of the expansion tank, and the liquid level will begin to drop. If the liquid level in the expansion tank is as low as the first liquid level, open the water supply valve. If the liquid level in the expansion tank rises to the second liquid level, close the water supply valve. S4, establishing a liquid level temperature compensation model for the actual liquid level of the expansion tank and the standard liquid level of the expansion tank; S5. Excluding the influence of other factors, when the change of the actual liquid level of the expansion tank is only related to the leakage of the heat medium water, first convert the actual liquid level change rate of the expansion tank into the standard liquid level change rate of the expansion tank according to the liquid level temperature compensation model, and then calculate the heat medium water leakage. The heat medium water leakage is the product of the standard liquid level change rate of the expansion tank and the cross-sectional area inside the expansion tank.

9. The method for detecting leakage of a heat medium water heat exchange system according to claim 8, It is characterized in that The first liquid level is 40% of the total liquid level in the expansion tank, and the second liquid level is 80% of the total liquid level in the expansion tank.

Images