Condensate conveying system of ORC (organic Rankine cycle) condensate generator set for avoiding flash evaporation phenomenon in equipment and pipeline

Abstract

The condensate conveying system for the ORC condensate generator sets is capable of avoiding the flash evaporation phenomenon in equipment and pipelines and comprises a flash evaporation tank, a plurality of ORC condensate generator sets, a bypass cooler and a high-pressure desalted water heat exchanger which are communicated through pipelines, and gate valves, flow meters and thermometers are installed in different areas of the communicated pipelines. A liquid level adjusting valve is arranged at an outlet of the flash tank, a manual valve is arranged on a feeding pipe of the ORC condensate generator set, a first adjusting valve set in linkage with a flow meter at the feeding end is arranged at the discharging end of the ORC condensate generator set, and the manual valve at the feeding end of the ORC condensate generator set in the working state is in a full-open state. The total amount of steam condensate in the ORC condensate generator set is kept constant through the first adjusting valve set at the outlet end. And the flash evaporation phenomenon of high-temperature condensate in the pipeline and equipment caused by the pressure change after the valve is adjusted in the existing pipeline can be effectively avoided, and the conditions of pipeline vibration, abnormal display of flow and temperature monitoring instruments and the like caused subsequently can be effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of condensate discharge systems for ORC condensate generator sets, and in particular to a condensate conveying system for an ORC condensate generator set which can avoid flash evaporation in equipment and pipelines. Background Art

[0002] Currently, if Figure 2 As shown, a flash tank is set in the deaerator tank and condensate station. The steam condensate is sent into the flash tank and the 1.5MPa and 0.7MPa steam condensates from the outer pipe enter the flash tank for flash evaporation respectively. The by-product 0.5MPa saturated steam is merged into the 0.5MPa steam outer pipe. A liquid level regulating valve is set at the bottom outlet of the flash tank, and the liquid level of the flash tank is controlled by adjusting the valve opening. After the 0.5MPa steam condensate passes through the regulating valve, part of it is directly sent to the heat exchange station as a heat source, and the other part passes through the regulating valve and enters two sets of ORC condensate generator sets for waste heat power generation. The excess condensate passes through the regulating valve 1280-HV-0003 and enters the bypass cooler for cooling. The condensate after passing through the ORC condensate generator set and the bypass cooler is combined and enters the high-pressure desalted water heat exchanger for cooling, and finally sent to the desalted water station for cooling through the circulating water heat exchanger, and then recovered to produce desalted water.

[0003] Among them, Figure 2 As shown, the bypass cooler process flow is: flash evaporation → bypass cooler inlet regulating valve → bypass cooler → bypass cooler outlet manual valve → high-pressure desalted water heat exchanger. The condensate system flow of the ORC condensate generator set is: flash tank → ORC condensate generator set inlet regulating valve → evaporator → preheater → preheater outlet manual valve → high-pressure desalted water heat exchanger. The saturated steam condensate output by the flash tank is 158°C and 0.5MPa. In order to recycle the heat in the 158°C and 0.5MPa saturated steam condensate, there are currently two sets of ORC condensate generator sets. The main uses of this set of equipment are: ① Use the waste heat in the condensate to generate electricity, improve the utilization rate of steam energy, and at the same time increase the power generation to achieve the purpose of energy saving and efficiency improvement; ② After cooling the condensate, the use of cooling circulating water can be reduced, while ensuring the safe operation of the subsequent condensate treatment system. Figure 2 shown.

[0004] The ORC condensate power generation process is summarized as follows: starting from the hot side outlet of the condenser, the working medium is a saturated pentafluoropropane working fluid liquid of 0.2MPa and 44.7℃. The working fluid is cooled by the condenser until the working fluid pump increases the pressure to 1.723MPa, enters the regenerator, and then enters the preheater. The working fluid liquid is preheated to 117℃ and enters the evaporator for evaporation at a temperature close to saturation. The 0.5MPa heat source condensate enters the evaporator from the flash tank, and the inlet pipeline is equipped with a regulating valve to adjust the condensate flow rate. The condensate is cooled to 121℃, and then enters the preheater, and finally cooled to 85℃ to go to the high-pressure desalted water heat exchanger. In the evaporator, the working fluid is heated and evaporated to form 116.8℃ steam, which enters the downstream turbine expander to do work and drives the generator to generate electricity through the gearbox. The exhaust gas (0.2MPa, 61.75℃) that has done work enters the regenerator for self-heat exchange with the supercooled working fluid at the outlet of the working fluid pump, and then enters the condenser to be cooled by the 30℃ circulating water to form a 0.2MPa, 44.7℃ saturated working fluid liquid, which then re-enters the working fluid pump for another cycle.

[0005] The designed heat source of the evaporator of the ORC condensate generator set is the 0.5MPa condensate from the flash tank. The quality of the heat source directly determines whether the unit can operate stably and how much power it can generate. If a large amount of steam is entrained in the heat source condensate, the calorific value of the condensate will be reduced, the power generation of the ORC condensate generator set will be reduced, and the operating conditions of the unit will fluctuate greatly. Since the heat source inlet pipeline is equipped with a regulating valve, the operation of the ORC unit has not been able to achieve automatic regulation since it was started, and because the condensate flow in the flash tank is unstable, it is often necessary to control the liquid level through a liquid level regulating valve. As a result, the temperature and flow of the heat source sent to the ORC condensate generator set are unstable, and the power generation of the unit cannot reach the designed value.

[0006] In addition, the inlet condensate temperature of the ORC condensate generator set and bypass cooler is 158℃. The action of the liquid level control valve often causes the pressure on the rear side of the control valve to drop, causing the high-temperature condensate to flash in the bypass cooler and pipeline, which causes the bypass cooler and pipeline to vibrate violently, and the flow and temperature monitoring instruments to display abnormalities, which has a great impact on the operational stability. The phenomena of pipeline fluid flashing and vibration not only occur in the ORC condensate power generation system, but also in all pipelines with high-temperature fluid passing through. Such problems will not only cause unstable operating conditions, but also affect the operating safety of equipment and pipelines, and even pose a threat to the safety of operators, so process improvement is imperative. Summary of the invention

[0007] In order to solve one or some technical problems existing in the prior art, the purpose of the present application is to provide a condensate conveying system for an ORC condensate generator set that avoids flash evaporation in equipment and pipelines, which can effectively solve the flash evaporation phenomenon of high-temperature condensate in pipelines and equipment caused by pressure changes after the regulating valve in the existing pipelines, as well as the subsequent pipeline vibration, flow and temperature monitoring instrument display abnormalities, etc.

[0008] In order to solve the above existing technical problems, this application adopts the following technical solutions:

[0009] A condensate conveying system of an ORC condensate generator set for avoiding flash evaporation in equipment and pipelines, comprising a flash tank connected by a pipeline, a plurality of sets of ORC condensate generator sets, a bypass cooler and a high-pressure desalted water heat exchanger, gate valves, flow meters and thermometers are installed in different areas of the connecting pipeline, a liquid level regulating valve is provided at the outlet of the flash tank, a plurality of sets of the ORC condensate generator sets and the bypass coolers are arranged in parallel between the liquid level regulating valve and the high-pressure desalted water heat exchanger, steam condensate flowing out of the flash tank outlet enters the ORC condensate generator set and / or the bypass cooler for cooling before entering the high-pressure desalted water heat exchanger, the ORC condensate generator A manual valve is provided on the feed pipe of the group, and a first regulating valve group linked to the flow meter at the feed end is provided at the discharge end of the ORC condensate generator group. The manual valve at the feed end of the ORC condensate generator group in working state is in a fully open state. The steam condensate flowing out of the flash tank preferentially enters the corresponding ORC condensate generator group through the manual valve for waste heat power generation. The excess steam condensate enters the bypass cooler for cooling, and then enters the high-pressure desalted water heat exchanger together with the condensate discharged from the ORC condensate generator group. The total amount of steam condensate in the ORC condensate generator group is linked to the operating load of the unit through the first regulating valve group at the outlet end.

[0010] Preferably, a second regulating valve group linked to the first regulating valve group is provided on the bypass cooler outlet pipe, and the liquid level in the flash tank is stably controlled by the second regulating valve group. At the same time, the flow rate of steam condensate entering the bypass cooler is automatically controlled by the second regulating valve group.

[0011] Preferably, the second regulating valve group is controlled in linkage with each of the ORC condensate generator sets, and when the ORC condensate generator set stops, the second regulating valve group is fully opened.

[0012] Preferably, the first regulating valve group and the second regulating valve group both include a main control valve and a bypass control valve, and both sides of the main control valve are connected in series through gate valves.

[0013] Preferably, a reflux bypass is provided between the liquid pipe manifold at the discharge end of each ORC condensate generator set and the liquid inlet pipe of the bypass cooler, and a reflux valve is provided on the reflux bypass. Part of the high-temperature steam condensate discharged from the ORC condensate generator set flows into the bypass cooler for secondary cooling after switching through the reflux bypass. The cooled condensate is then mixed with the condensate on the liquid inlet pipe of the high-pressure desalted water heat exchanger and then enters the high-pressure desalted water heat exchanger.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] After the process improvement, it can provide stable operating conditions, so that the speed of steam condensate discharge system can maintain the pressure inside the heat exchanger stable and prevent flashing caused by too fast condensate discharge. It can ensure the stable operation of pipelines and ORC condensate generator sets, guarantee the power generation of ORC condensate generator sets, and provide good conditions for the monitoring of online monitoring instruments such as flow meters to ensure the accuracy of monitoring results. At the same time, after the vibration of pipelines and equipment is eliminated or reduced, the safety of equipment and the personal safety of operators can be better guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the improved process flow chart of the present invention;

[0017] Figure 2 This is a process flow chart before the improvement of the present invention;

[0018] In the figure: 1. First regulating valve group; 2. Second regulating valve group; 3. High-pressure desalted water heat exchanger; 4. Bypass cooler; 5. Reflux valve; 6. Flash tank; 7. Liquid level regulating valve; 8. Reflux bypass; 9. Manual valve; 10. ORC condensate generator set; 11. Bypass control valve; 12. Main control valve;. DETAILED DESCRIPTION

[0019] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0020] In the description of the present application, it should be understood that the terms "up", "down", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0021] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0022] like Figure 1 As shown, a condensate conveying system of an ORC condensate generator set 10 for avoiding flashing in equipment and pipelines comprises a flash tank 6, a plurality of sets of ORC condensate generator sets 10, a bypass cooler 4 and a high-pressure desalted water heat exchanger 3 connected by pipelines, gate valves, flow meters and thermometers are installed in different areas of the connecting pipelines, a liquid level regulating valve 7 is provided at the outlet of the flash tank 6, a plurality of sets of the ORC condensate generator sets 10 and the bypass coolers 4 are arranged in parallel between the liquid level regulating valve 7 and the high-pressure desalted water heat exchanger 3, and the steam condensate flowing out of the outlet of the flash tank 6 enters the ORC condensate generator set 10 and / or the bypass cooler 4 for cooling before entering the high-pressure desalted water heat exchanger 3, characterized in that: the ORC condensate A manual valve 9 is provided on the feed pipe of the ORC condensate generator set 10, and a first regulating valve group 1 linked to the flow meter at the feed end is provided at the discharge end of the ORC condensate generator set 10. The manual valve 9 at the feed end of the ORC condensate generator set 10 in working state is fully open, and the steam condensate flowing out of the flash tank 6 preferentially enters the corresponding ORC condensate generator set 10 through the manual valve 9 for waste heat power generation. The excess steam condensate enters the bypass cooler 4 for cooling, and then enters the high-pressure desalted water heat exchanger 3 together with the condensate discharged from the ORC condensate generator set 10. The total amount of steam condensate in the ORC condensate generator set 10 is linked to the operating load of the unit through the first regulating valve group 1 at the outlet end.

[0023] In the actual production process, when the 158°C, 0.5MPa saturated steam condensate output from the flash tank 6 is used for waste heat power generation, the gate valves and liquid level regulating valves 7 at various positions are generally in a fully open state, and the manual valve 9 on the feed pipe of the ORC condensate generator set 10 is opened in a targeted manner according to the output flow. For example, when the total outflow is less than the heat exchange capacity of two ORC condensate generator sets 10, generally only the manual valve 9 at the inlet of one ORC condensate generator set 10 is opened, and the excess saturated steam condensate enters the bypass cooler 4 for condensation. By analogy, when the saturated steam condensate can be fully utilized by the ORC condensate generator set 10, the saturated steam condensate does not enter the feed pipe of the bypass cooler 4. At present, each heat source inlet pipeline of each ORC condensate generator set 10 is equipped with a regulating valve. When the regulating valve is turned on and off, flash will occur behind the valve, causing vibration of the pipeline and equipment. Moreover, the inlet condensate temperature of the ORC condensate generator set 10 and the bypass cooler 4 is 158°C. Since the start of operation, the operation of the ORC condensate generator set 10 has not been able to achieve automatic regulation. Moreover, due to the unstable condensate flow in the flash tank 6, the liquid level needs to be controlled by the liquid level regulating valve 7. The action of the liquid level regulating valve 7 often causes the pressure behind the regulating valve to decrease, causing the high-temperature condensate to flash in the ORC condensate generator set 10 and the pipeline, thereby causing the ORC condensate generator set 10 and the pipeline to vibrate violently, and the flow and temperature monitoring instruments to display abnormalities, resulting in unstable temperature and flow of the heat source sent to the ORC condensate generator set 10, and the power generation of the unit cannot reach the design value. This has a very large impact on the operational stability. The phenomena of pipeline fluid flashing and vibration not only occur in the ORC condensate power generation system, but also basically occur in all pipelines with high-temperature fluid passing through. Such problems will not only cause unstable operating conditions, but also affect the operating safety of equipment and pipelines, and even pose a threat to the safety of operators. Therefore, the existing flow control method is improved, wherein the inlet regulating valve is replaced by a manual valve 9 and is in a normally open state, and the outlet manual valve 9 controls the flow through the first regulating valve group 1 linked to the flow meter at the feed end, so that the total amount of heat source flow entering the ORC condensate generator set 10 is kept constant, and the first regulating valve group 1 on the outlet pipe is automatically adjusted by the inlet amount, so that it can be linked with the operating load of the unit. The process flow of the improved condensate system is flash tank 6 → ORC condensate generator set 10 inlet manual valve 9 → evaporator → preheater → preheater outlet first regulating valve group 1 → high-pressure desalted water heat exchanger 3. After the improvement of the control process, the outflowing condensate temperature is generally around 80-90°C, and the flashing phenomenon is basically eliminated.After the improvement, the problem that the ORC condensate generator set 10 cannot realize automatic adjustment during operation can be avoided, and at the same time, the problem that the temperature and flow of the heat source sent to the ORC condensate generator set 10 are unstable due to the unstable condensate flow in the flash tank 6, and the power generation of the unit cannot reach the designed value can be solved. During operation, it is no longer necessary to adjust the liquid level of the original liquid level regulating valve 7, the operation stability is better, the operation is simpler, and the existing problems are effectively solved.

[0024] A further improvement is that a second regulating valve group 2 linked to the first regulating valve group 1 is provided on the outlet pipe of the bypass cooler 4, and the liquid level in the flash tank 6 is stably controlled by the second regulating valve group 2. At the same time, the flow rate of steam condensate entering the bypass cooler 4 is automatically controlled by the second regulating valve group 2.

[0025] Since the improved liquid level regulating valve 7 is in a normally open state, the feed end of the bypass cooler 4 is also in a fully open state, resulting in the discharge volume of the flash tank 6 being in a state of maximum flow. In this state, it is easy for steam condensate to waste heat energy due to excessive flow into the bypass cooler 4. At this time, after installing a second regulating valve group 2 linked to the first regulating valve group 1 on the outlet pipe of the bypass cooler 4, the opening of the second regulating valve 2 can be automatically controlled by calculating the total flow and the flow of the first regulating valve group 1, thereby achieving the purpose of stably controlling the liquid level in the flash tank 6 through the second regulating valve group 2, thereby avoiding the waste of high-temperature steam condensate.

[0026] At the same time, the original regulating valve is in front of the bypass cooler 4. When the opening is adjusted, the bypass cooler 4 and the inlet pipeline vibrate greatly, causing leakage of the internal pipeline of the equipment. The flow rate of saturated steam condensate entering the bypass cooler 4 is controlled by the second regulating valve group 2 on the outlet pipeline of the bypass cooler 4. When the flow meter shows a flow change, the opening of the second regulating valve group 2 automatically changes, so that when the opening of the first regulating valve group 1 becomes larger, the opening of the second regulating valve group 2 naturally decreases. When the total amount passing through each first regulating valve group 1 is greater than or equal to the discharge amount, the second regulating valve group 2 is closed, and when the flow rate of the first regulating valve group 1 is 0, the second regulating valve group 2 is fully opened; in the process of controlling the flow rate of the steam condensate entering the bypass cooler 4, the inlet regulating valve of the bypass cooler 4 is no longer installed at the feed port, which can avoid problems such as pipeline vibration and flash evaporation in the bypass cooler 4 due to changes in the flow rate at the feed port. The manual valve 9 at the outlet of the bypass cooler 4 is also replaced by the second regulating valve group 2 linked to the inlet flow meter, so that the improved process flow is flash tank 6 → bypass cooler 4 → second regulating valve group 2 at the outlet of bypass cooler 4 → high-pressure desalted water heat exchanger 3, which can solve the problem of flash evaporation of high-temperature condensate in the pipeline and bypass cooler 4 caused by pressure changes after the regulating valve, and can avoid subsequent pipeline vibration, abnormal display of flow and temperature monitoring instruments, etc.

[0027] Since the heat source of the evaporator of the ORC condensate generator set 10 is designed to be 0.5MPa condensate from the flash tank 6, the quality of the heat source directly determines whether the unit can operate stably and how much power it can generate. If a large amount of steam is entrained in the heat source condensate, it will lead to a decrease in the calorific value of the condensate, a decrease in the power generation of the ORC condensate generator set 10, and large fluctuations in the operating conditions of the unit. After the improvement, the liquid level regulating valve 7 and the inlet pipeline valves of each device are all in a fully open state, which effectively solves the occurrence of these situations. At the same time, after the process improvement of the ORC condensate generator set 10 and the bypass cooler 4, the advantages are as follows:

[0028] 1. The flash phenomenon occurring on the condensate main pipe from the flash tank 6 to the ORC condensate generator set 10 can be reduced or even eliminated, and the abnormal vibration of the condensate pipeline and the displacement of the pipe support can be eliminated;

[0029] 2. The flash phenomenon occurring on the condensate inlet branch pipeline from the flash tank 6 to the ORC condensate generator set 10 can be reduced or even eliminated, and the abnormal vibration of the condensate pipeline and the inaccurate flow meter measurement can be eliminated;

[0030] 3. The flash phenomenon occurring on the condensate inlet branch pipeline from the flash tank 6 to the bypass cooler 4 can be reduced or even eliminated, and the abnormal vibration of the condensate pipeline, condensate regulating valve and bypass cooler 4 can be reduced or eliminated;

[0031] 4. The inaccurate measurement of the condensate inlet flowmeter of the ORC condensate generator set 10 due to the flash phenomenon can be eliminated, ensuring that the operating load of the ORC unit can be adjusted normally; the inaccurate measurement of the condensate inlet flowmeter entering the bypass cooler 4 due to the flash phenomenon can also be eliminated, and the operating load of the bypass cooler 4 can be adjusted according to the working conditions to ensure the stable operation of the condensate system;

[0032] 5. After the condensate flow rate entering the ORC unit increases, the amount of condensate remaining entering the bypass cooler 4 decreases, the amount of circulating water used to cool the condensate decreases, and energy consumption is reduced.

[0033] After the process adjustment, the condensate flow entering the ORC condensate generator set 10 increases, the remaining condensate entering the bypass cooler 4 will be reduced accordingly, and the amount of circulating water used to cool the condensate will be reduced accordingly, thereby reducing the consumption of cooling circulating water.

[0034] A further improvement is that the second regulating valve group 2 is controlled in linkage with each of the ORC condensate generator sets 10, and when the ORC condensate generator set 10 stops, the second regulating valve group 2 is fully opened.

[0035] During use, the ORC condensate generator set 10 may fail and trip. When the ORC condensate generator set 10 trips during operation, the feed port can no longer feed. At this time, the first regulating valve group 1 will automatically shut down according to the flow rate, but the steam condensate is still kept in the output state, which will cause the internal pipeline pressure to increase. Therefore, in order to avoid the flow problem, the second regulating valve group 2 is linked with each ORC condensate generator set 10. When the ORC condensate generator set 10 trips, the excess steam condensate can be condensed and discharged through the bypass cooler 4 in time, thereby solving the problem that the steam condensate cannot be discharged in time after the ORC condensate generator set 10 suddenly has a problem, causing the pressure change in the conveying pipeline and causing production accidents. The operating conditions of the ORC condensate generator set 10 can be improved. After the operating conditions of the ORC unit are optimized, the temperature of the condensate at the outlet of the preheater after the unit can reach the design value. After the operating load is increased, the power generation of the unit can be increased accordingly, achieving the purpose of energy saving and efficiency improvement. At the same time, after the load of the ORC unit is increased, the normal operation of the subsequent condensate recovery process can be guaranteed.

[0036] As a further improvement, the first regulating valve group 1 and the second regulating valve group 2 both include a main control valve 12 and a bypass control valve 11, and both sides of the main control valve 12 are connected in series through gate valves.

[0037] When flow control is performed through the first regulating valve group 1 and the second regulating valve group 2, the main control valve 12 is generally in operation and the bypass control valve 11 is in a closed state. When a problem occurs in the main control valve 12, it is automatically closed and automatically switched to the bypass control valve 11 to open the flow. The main control valve 12 can be cut off and repaired through the gate valves at both ends to avoid the situation where a single valve control cannot perform flow regulation normally due to damage.

[0038] A further improvement is that a reflux bypass 8 is provided between the liquid pipe manifold at the discharge end of each ORC condensate generator set 10 and the liquid inlet pipe of the bypass cooler 4, and a reflux valve 5 is provided on the reflux bypass 8. Part of the high-temperature steam condensate discharged from the ORC condensate generator set 10 flows into the bypass cooler 4 for secondary cooling after switching through the reflux bypass 8. The cooled condensate is then mixed with the condensate on the liquid inlet pipe of the high-pressure desalted water heat exchanger 3 and then enters the high-pressure desalted water heat exchanger 3.

[0039] When multiple ORC condensate generator sets 10 are started at the same time, no high-temperature steam condensate will flow into the feed pipe of the bypass cooler 4. At this time, although the high-temperature steam condensate flowing out of the flash tank 6 is cooled by the ORC condensate generator set 10, the temperature of the condensate flowing out is still high. When the condensate with too high temperature enters the high-pressure desalted water heat exchanger 3, the subsequent condensate temperature will be high. After entering the desalted water station condensate treatment system, the resin will be decomposed. Therefore, a condensate pipe is added between the liquid pipe main pipe at the discharge end of each ORC condensate generator set 10 and the liquid inlet pipe of the bypass cooler 4. A reflux bypass 8 with a reflux valve 5 is provided, so that a part of the high-temperature steam condensate can be transported from the reflux bypass 8 to the bypass cooler 4 for rapid cooling after the reflux valve 5 is opened, and then the low-temperature condensate flows into the feed pipe of the high-pressure desalted water heat exchanger 3 for mixing and cooling, and finally flows into the high-pressure desalted water heat exchanger 3, thereby avoiding the situation where the entering condensate temperature is too high, so that when the condensate enters the high-pressure desalted water heat exchanger 3, the subsequent condensate temperature will not be high, thereby avoiding the phenomenon of resin decomposition after entering the desalted water station condensate treatment system.

[0040] The comparison of the condensate discharge system of the entire ORC condensate generator set 10 before and after the improvement is as follows:

[0041] 1. Before the process adjustment, the condensate in the flash tank 6 is sent to the ORC condensate generator set 10 and the bypass cooler 4 after passing through the outlet liquid level regulating valve 7. When the liquid level and external supply flow of the flash tank 6 are adjusted, flash evaporation and steam entrainment in the condensate often occur in the condensate main pipe, resulting in large pipeline vibration and displacement of the pipe support.

[0042] After the process adjustment, the original liquid level regulating valve 7 of the flash tank 6 is fully opened, and the valve is no longer used to control the liquid level and external supply flow. Therefore, the pressure drop caused by the change in the opening of the liquid level regulating valve 7 will no longer appear on the condensate main pipe from the flash tank 6 to the ORC condensate generator set 10, and the flash evaporation and steam entrainment in the condensate pipeline after the original liquid level regulating valve 7 can be eliminated, and subsequent pipeline vibration and pipe support displacement basically no longer occur.

[0043] 2. Before the process adjustment, the condensate regulating valve of the ORC condensate generator set 10 is installed on the condensate inlet pipeline of the ORC unit. The load adjustment of the ORC unit needs to be controlled by the opening of the condensate inlet regulating valve. When the condensate inlet regulating valve is not fully opened, flash evaporation and steam entrainment in the condensate will occur in the pipeline after the regulating valve, resulting in large pipeline vibration and the falling off of the sliding pipe support.

[0044] After the process flow is adjusted, the original regulating valve entering the ORC condensate generator set 10 is changed to a manual valve 9, and is kept in a fully open state during operation. A second regulating valve group 2 is installed on the discharge pipe of the ORC condensate generator set 10, which can eliminate the flash evaporation and pipeline vibration originally occurring in the condensate inlet pipeline and evaporator of the ORC condensate generator set 10;

[0045] 3. Before the process adjustment, the condensate in the flash tank 6 passes through the condensate regulating valve before entering the bypass cooler 4. When adjusting the condensate inlet flow rate of the bypass cooler 4, the condensate regulating valve, connecting pipelines and the bypass cooler 4 often vibrate violently due to the flash evaporation of the condensate after the inlet regulating valve and the phenomenon of steam entrained in the condensate, which brings huge hidden dangers to the safe operation of the regulating valve and the bypass cooler 4.

[0046] After the process flow is adjusted, the original regulating valve entering the bypass cooler 4 is cancelled and kept in full open state during operation, and the original outlet manual valve 9 is replaced by the second regulating valve group 2. After the adjustment, the flash evaporation phenomenon occurring after the original regulating valve at the inlet of the bypass cooler 4 condensate can be eliminated, and the abnormal vibration phenomenon of the regulating valve body, the condensate inlet pipeline of the bypass cooler 4 and the inside of the bypass cooler 4 can be basically eliminated.

[0047] 4. Before the process adjustment, the condensate inlet flowmeter from the flash tank 6 level regulating valve 7 to the ORC condensate generator set 10 and the condensate inlet flowmeter entering the bypass cooler 4 were both orifice flowmeters. Because the pipeline where the condensate flowmeter of the ORC condensate generator set 10 is located often flashes, steam is entrained in the condensate pipeline, resulting in inaccurate flowmeter measurement and long-term over-range status (displaying 240m 3 / h), the data cannot be monitored normally, and the ORC condensate generator set 10 cannot be adjusted according to the flow rate. Similarly, the condensate flow meter at the inlet of the bypass cooler 4 fluctuates too much for a long time due to the flash evaporation problem in the pipeline, and the operating load of the bypass cooler 4 cannot be adjusted according to the flow rate.

[0048] After the process adjustment, the original liquid level regulating valve 7 at the outlet of the flash tank 6 is fully opened, and the condensate inlet regulation from the flash tank 6 to the ORC condensate generator set 10 is changed to the manual valve 9 being fully opened. The flashing phenomenon on the condensate main pipe and the branch pipeline entering the ORC condensate generator set 10 has been eliminated, the flow meter monitoring data can be displayed normally, and the sum of the unit inlet condensate flow rate and the bypass cooler 4 inlet condensate flow rate is basically consistent with the condensate inlet flow meter reading of the high-pressure desalted water heat exchanger 3.

[0049] 5. Before the process adjustment, the operating load of the ORC condensate generator set 10 could not reach the design value (maximum gross power generation of about 1500kW) due to various factors such as the temperature drop caused by the flash evaporation of the steam condensate.

[0050] After the process adjustment, the condensate inlet temperature of a single ORC condensate generator set 10 can reach the design temperature and pressure values ​​(158°C, 0.5MPa), meeting the needs of full-load operation. After the operating conditions are improved, the power generation can reach the design value (gross power generation 1908kW).

[0051] 6. Before the process adjustment, the ORC condensate generator set 10 could not operate at full load, resulting in a large amount of condensate entering the bypass cooler 4 and a large amount of cooling circulating water, resulting in a waste of cooling circulating water.

[0052] After the process adjustment, the condensate flow entering the ORC condensate generator set 10 increases, the remaining condensate entering the bypass cooler 4 will be reduced accordingly, and the amount of circulating water used to cool the condensate will be reduced accordingly, thereby reducing the consumption of cooling circulating water.

[0053] The above-mentioned implementation modes are only preferred implementation modes of the present application and cannot be used to limit the scope of protection of the present application. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present application shall fall within the scope of protection required by the present application.

Claims

1. A condensate conveying system for an ORC condensate generator set for avoiding flashing in equipment and pipelines, comprising a flash tank (6), a plurality of ORC condensate generator sets (10), a bypass cooler (4) and a high-pressure desalted water heat exchanger (3) connected by a pipeline, gate valves, flow meters and thermometers are installed in different areas of the connecting pipeline, a liquid level regulating valve (7) is provided at the outlet of the flash tank (6), a plurality of ORC condensate generator sets (10) and the bypass cooler (4) are arranged in parallel between the liquid level regulating valve (7) and the high-pressure desalted water heat exchanger (3), and steam condensate flowing out of the outlet of the flash tank (6) enters the ORC condensate generator set (10) and / or the bypass cooler (4) for cooling before entering the high-pressure desalted water heat exchanger (3), characterized in that: A manual valve (9) is provided on the feed pipe of the ORC condensate generator set (10), and a first regulating valve group (1) is provided at the discharge end of the ORC condensate generator set (10) in linkage with the flow meter at the feed end. The manual valve (9) at the feed end of the ORC condensate generator set (10) in a working state is in a fully open state. The steam condensate flowing out of the flash tank (6) preferentially enters the corresponding ORC condensate generator set (10) through the manual valve (9) for waste heat power generation. The excess steam condensate enters the bypass cooler (4) for cooling, and then enters the high-pressure desalted water heat exchanger (3) together with the condensate discharged from the ORC condensate generator set (10). The total amount of steam condensate in the ORC condensate generator set (10) is regulated in linkage with the operating load of the unit through the first regulating valve group (1) at the outlet end.

2. According to claim 1, a condensate conveying system for an ORC condensate generator set that avoids flash evaporation in equipment and pipelines is characterized by: A second regulating valve group (2) linked to the first regulating valve group (1) is provided on the outlet pipe of the bypass cooler (4); the liquid level in the flash tank (6) is stably controlled by the second regulating valve group (2); and at the same time, the flow rate of the steam condensate entering the bypass cooler (4) is automatically controlled by the second regulating valve group (2).

3. The condensate delivery system of an ORC condensate generator set for avoiding flash evaporation in equipment and pipelines according to claim 2, characterized in that: The second regulating valve group (2) is controlled in linkage with each of the ORC condensate generator sets (10); when the ORC condensate generator set (10) stops, the second regulating valve group (2) is fully opened.

4. The condensate delivery system of an ORC condensate generator set for avoiding flash evaporation in equipment and pipelines according to claim 2, characterized in that: The first regulating valve group (1) and the second regulating valve group (2) both comprise a main control valve (12) and a bypass control valve (11), and both sides of the main control valve (12) are connected in series via gate valves.

5. A condensate delivery system for an ORC condensate generator set that avoids flashing in equipment and pipelines according to any one of claims 1 to 4, characterized in that: A reflux bypass (8) is provided between the liquid pipe manifold at the discharge end of each of the ORC condensate generator sets (10) and the liquid inlet pipe of the bypass cooler (4), and a reflux valve (5) is provided on the reflux bypass (8). Part of the high-temperature steam condensate discharged from the ORC condensate generator set (10) flows into the bypass cooler (4) for secondary cooling after being switched through the reflux bypass (8). The cooled condensate is then mixed with the condensate on the liquid inlet pipe of the high-pressure desalted water heat exchanger (3) and then enters the high-pressure desalted water heat exchanger (3).

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