CN110530660A - A kind of slot type photo-thermal power station loop performance detection system and its detection method - Google Patents

Abstract

The invention provides a circuit performance detection system of a trough-type photothermal power station, which is connected to a single test circuit through a pipeline, and the single test circuit is isolated from other circuits. The detection systems are installed in the box (14) and are movable, including : HTF system (1); control system (2); and sensor system (3); control system (2) sends a control signal to the HTF system (1) through the control wiring to control the HTF system (1) to complete the detection system and The cycle of HTF in a single test loop; the measuring device of the sensor system (3) is set on the pipeline in the system, used to measure the flow rate and inlet and outlet temperature of a single test loop (16), and analyze the performance of a single loop of a trough-type photothermal power station , while monitoring each device in the detection system. The corresponding circuit performance detection method is also disclosed, including: adding new HTF into the expansion tank; preheating the circuit; injecting HTF into the circuit; focusing and tracking and testing; cooling the circuit; emptying the HTF.

Description

A loop performance detection system and detection method of a trough-type photothermal power station

technical field

The invention relates to a technology for detecting the performance of solar thermal power generation, and in particular to a performance detection for a loop of a trough-type photothermal power station.

Background technique

Concentrated Solar Power (CSP for short) is a concentrated solar thermal power generation technology, which relies on various concentrating mirrors to gather the direct radiation (DNI) of the sun, and heats the fluid working fluid (heat transfer fluid, under It is called "HTF") to collect heat, and then generate high-temperature steam through heat exchange, which drives the steam turbine to generate electricity. The current mainstream technical route of CSP is divided according to the way of solar energy collection, mainly divided into four types: tower type, trough type, Fresnel type and dish type. Technology is the most. Trough solar thermal power generation arranges many trough parabolic concentrators in series and parallel, collects heat through fluid working medium to reach a higher temperature, and then generates steam through further heat exchange to drive a turbogenerator unit to generate electricity. Trough solar thermal power generation is mainly composed of four parts: concentrating heat collection device (or "mirror field"), heat exchange system, heat storage device and steam turbine power generation device. The schematic diagram of the system is shown in Figure 1.

Although the trough technology has been developed for many years, the technology maturity is relatively high, and commercialization has basically been realized, but there are still deficiencies in the performance testing methods and methods of the power station. At present, the mirror field performance test of the trough solar thermal power station is certified by the performance of the components However, there is no corresponding performance testing method and testing method for the smallest independent unit that composes the trough mirror field—a single loop, let alone a general single-loop performance testing standard. At present, the construction method of domestic solar thermal power plants is mainly based on the combination of island subcontracting and power plant general contracting, which is different from the single power plant general contracting mode abroad. , it is necessary to conduct a separate and complete performance inspection and acceptance of the single circuit of the trough mirror field, so as to determine the performance indicators before and after the handover, so as to achieve a clear division of rights and responsibilities, and prevent subsequent legal disputes and potential technical risks. Since international CSP projects are mainly based on the general contracting model of power plants, the performance testing steps of a single circuit are often ignored or other alternative parameters (such as the annual power generation of the entire power plant) are used as performance substitute indicators, so there is currently a lack of professional testing. Therefore, it will seriously affect the objective evaluation of the performance of the trough mirror field, and may lead to a long commissioning cycle of the power station, difficulties in performance testing and acceptance, subcontractors and general contractors shuffling responsibilities and a series of related interest disputes and other issues .

At present, there are some small-scale test benches and testing equipment for trough circuits, but they are all fixed rather than mobile. If testing is required, the photothermal components to be tested must be disassembled and transported to the location of the test bench and testing equipment. Inspection, and the inspection work usually takes several days to several weeks, coupled with intermediate transportation, the entire inspection cycle will take a long time. In addition, since only some photothermal components are submitted for inspection, it is often impossible to accurately and completely measure the operation indicators of each circuit in the actual power station. Therefore, this detection method is insufficient for the circuit performance detection of trough power stations .

In a word, there is following shortcoming in prior art:

1. There is no reliable method to detect the overall photothermal conversion efficiency of a single trough circuit installed on the project site during the project construction;

2. After the completion of the project, the entire site can be debugged, but there is no means to test the performance of each specific subsystem;

3. When a circuit fails, there is a lack of means to evacuate and inject heat transfer fluid after system isolation of a single circuit;

4. The heat collection field occupies a large area, and the fixed equipment cannot flexibly measure the performance of the collector circuit at any position in the heat collection field;

5. In terms of system performance acceptance, due to the unclear boundaries of contract terms, mutual buck-passing and time delays seriously slowed down the construction time.

Contents of the invention

In order to overcome the defects existing in the prior art, the present invention provides a loop performance detection system for a trough-type photothermal power station, which is used to test the thermal performance of each trough loop. The whole system is equipped with corresponding equipment and pipelines, and also considers The portability and the container that houses the equipment pipelines allow for convenient and flexible inspection features.

The object of the present invention is to provide a loop performance detection system of a trough-type photothermal power station, the detection system is connected to a single test loop (16) through a pipeline, and the single test loop (16) is isolated from other loops, and the detection system is installed Inside the box (14), and being removable, includes:

HTF system(1);

control system (2); and

sensor system (3);

Wherein the control system (2) sends a control signal to the HTF system (1) through the control wiring to control the HTF system (1) to complete the detection of HTF in the detection system and in the single test loop (16). cycle;

The measuring device of the sensor system (3) is arranged on the pipeline in the system, and is used to measure the flow rate and the inlet and outlet temperature of a single test loop (16), and is used to analyze the performance of a single loop of the trough-type photothermal power station, and at the same time Monitor each device in the detection system, so that the detection system can run safely and reliably.

Preferably, also include: compressed air or inert gas system (4), described compressed air or inert gas system (4) is connected to expansion tank (7), cooling system (6) and detection system pipeline, is used for sealing HTF system (1), maintain the pressure of the connected expansion tank (7), cooling system (6), loop preheating system, circulating pump (5), piping system (15) and single test loop (16) and supply pressure to the single test loop ( 16) Inject or empty HTF.

Preferably, the compressed air or inert gas system (4) includes one or more gas cylinders, each of which is equipped with a separate valve, and the gas cylinders are placed vertically upward on the performance detection system, and placed In the box (14) or outside the box (14) close to the box (14), each gas cylinder is also provided with a separate pressure regulator, and is equipped with a check valve.

Preferably, a gas cylinder heat insulation and heat preservation cabinet is arranged inside the box (14), and a first electric heater (10-1) is arranged outside the gas cylinder heat insulation and heat preservation cabinet to heat the gas cylinder heat insulation and heat preservation cabinet, Thereby guaranteeing that the surface temperature of the gas cylinder reaches the minimum requirement, there is a horizontal beam above the box (14), on which a pulley is arranged, and a manual chain hoist is installed on the pulley to lift the gas cylinder from the ground to the performance testing on the system.

Preferably, the HTF system (1) includes a circulation pump (5), an expansion tank (7), a cooling system (6) and a second electric heater (10-2) connected by pipelines; wherein:

The circulation pump (5) is used to drive the loop performance detection system of the trough-type photothermal power station and the circulation of HTF in the single test loop (16), and the circulation pump (5) provides the required flow and pressure difference in real time;

The expansion tank (7) is used to store the HTF used for testing and absorb volume expansion when the HTF is heated and expanded. The expansion tank (7) is installed horizontally and is connected with the compressed air or inert gas system (4) to maintain the pressure of the system scope;

The cooling system (6) is an air cooler or a water cooler, which is used to dissipate the heat collected by a single test circuit (16), and adjust the heat dissipation by adjusting the fan speed of the air cooler or the cold water flow of the water cooler The purpose is to make the outlet temperature meet the set requirements;

The second electric heater (10-2) is arranged on the pipeline of the HTF system (1), the second electric heater (10-2) is in the form of a thermal resistance, and the resistance value of the thermal resistance is Related to the HTF characteristics and pipeline heat dissipation characteristics, the second electric heater (10-2) is used to maintain the temperature of the HTF in an appropriate range, and the second electric heater (10-2) contains instruments to ensure that it is in the corresponding correct operation within the operating range shown in the data sheet, the meter includes a temperature probe as a safety element, and the second electric heater (10-2) also includes a heating group with a control board that allows receiving from The signal of the temperature probe, the temperature probe is used to measure the temperature of the measurement point in the HTF system (1), and the temperature probe controls the start and stop of the thermal resistance under normal operation.

Preferably, the sensor system (3) includes a temperature sensor, a flow meter, a pressure sensor and a liquid level gauge, and the temperature sensor includes at least two, which are respectively arranged at the inlet and outlet of the single test circuit (16) for measuring single test circuit (16) inlet and outlet temperature; the flow meter is arranged at the outlet of the control valve downstream of the circulating pump, and the control system controls the circulation in the HTF system and the single test circuit (16) by adjusting the circulating pump and the control valve The flow of HTF, control the detection speed and ensure that the detection process is consistent with the actual working process of the trough solar power generation system, according to the inlet and outlet temperature of a single test loop (16) and the HTF flow in the loop, calculate the thermal power of the loop The most important pressure sensor is arranged in the expansion tank and the inlet and outlet of the single test circuit (16), respectively measuring the pressure in the expansion tank and the pressure value of the single test circuit (16), for judging and monitoring Whether the system and the single test loop (16) are running normally, other positions of the detection system should also be provided with pressure measuring points if necessary, to ensure the overall safety of the system; the liquid level gauge is arranged on the expansion tank to measure the liquid level of HTF in the expansion tank, When the liquid level is higher than 85% of the total height of the expansion tank (7), the system alarm prompts to discharge HTF, and when the liquid level is lower than the minimum allowable liquid level of the expansion tank (7), the system alarm prompts to replenish HTF in time.

Preferably, it also includes: a dissipative separation system (8), the dissipative separation system (8) includes a dissipative separation tank, which stores a certain amount of water inside, and can be separated from the expansion tank (7) pressure relief valve interface pipe The HTF contained in the discharged tail gas and the degradation products produced by high temperature cracking, when the dissipation separation system (8) is in working condition, its contents are water, HTF and the degradation products, and the dissipation separation tank is directly connected to the external The environment is connected.

Preferably, an HTF injection pump (9) is also included for injecting HTF into the performance detection system, and the HTF injection pump (9) has the characteristic of using HTF as a medium and being capable of continuous operation.

Preferably, the pipeline system (15) is used for the internal connection of the performance detection system and the connection between the performance detection system and a single test circuit (16). The pipeline system (15) can be divided into the following according to its function and the medium passing through it: Four subsystems:

The HTF pipeline subsystem is used to connect the HTF system (1) with other parts of the detection system;

The dissipation separation pipeline subsystem is used to connect the dissipation separation tank (8) with other parts of the detection system;

The expansion tank piping subsystem is used to connect the expansion tank (7) to other parts of the detection system, and the expansion tank piping subsystem is sealed to the expansion tank (7);

The gas pipeline subsystem is used to connect the compressed air or inert gas system (4) with other parts of the detection system;

Preferably, it also includes a single test circuit preheating system made up of a preheating fan (12) and a third electric heater (10-3), which is used to preheat the empty pipeline of a single test circuit (16), thereby avoiding Before the single test circuit (16) is injected with HTF, because the temperature of the pipeline is too low to cause HTF to solidify, the preheating system of the single test circuit makes the air heated by the third electric heater (10-3) through the preheating fan (12) Or the inert gas can be preheated through the loop pipeline.

Preferably, it also includes a cyclone separation device (11) arranged in a single test circuit (16), the cyclone separation device (11) is set so that the air or inert gas heated by the thermal resistance driven by the preheating fan (12) passes through the circuit In the process of the pipeline, the HTF droplets present in the circuit move with the air flow, and the filter and separator arranged in the cyclone separation device (11) are used to remove it before it reaches the preheating fan (12), and the collected HTF After being collected by the separator, the HTF is transported to the dissipation separation system (8) or a separate storage container through an automatic valve.

Preferably, the loop performance detection system is equipped with an anemometer, which is installed on the top of the test system or at a certain height near it, and the wind speed is measured and transmitted to the control system (2), so as to avoid damage to a single test loop by a sudden strong wind during the test ( 16) on the collector.

Preferably, the loop test system of the trough-type photothermal power station is used in conjunction with a weather station (13), and the weather station (13) at least includes: an anemometer, a temperature and humidity meter, and a solar irradiance meter. The weather station (13) consists of The loop test system is integrated or provided independently by the site, and the weather station (13) is used to record the environmental parameters required for the operation of the test system, and the environmental parameters are used to determine the thermal performance of a single test loop (16); The circuit is safe, and the control system of the weather station (13) collects the data information of each sensor in real time, and performs data information processing.

The purpose of the present invention is also to provide a loop performance detection method based on the loop performance detection system of the above-mentioned trough-type photothermal power station, including steps:

Step 1, HTF addition: add new HTF to the expansion tank;

Step 2: loop preheating: use compressed air or inert gas system (4), preheating fan (12) and third electric heater (10-3) to preheat a single test loop (16) to increase the temperature of the loop to be tested , so as to prevent the HTF from solidifying or damage the circuit components due to excessive thermal stress on a single test circuit (16) due to an excessive temperature difference;

Step 3: Inject HTF into the circuit: Inject HTF into the connected pipeline (including flexible hose) and the circuit to ensure that HTF is not solidified, thermal stress is avoided, and air or inert gas bubbles remain in the circuit;

Step 4, focus tracking and testing: the collector continuously tracks the sun to focus, heats the HTF to a specified temperature, and records the output data of a single test loop (16) at each time, and then compares it with the DNI data at the corresponding time and perform calculations;

Step 5: loop cooling: before the single test loop (16) and the detection system are emptied of the HTF, the temperature of the HTF is cooled down rapidly through the cooling system;

Step 6: Empty the HTF: Empty the HTF in the single test loop (16), the flexible hose and the connecting pipe to complete the test of one loop.

Preferably, between said step 3 and step 4, also include:

Ordinary protection: Turn the collector to a safe position, circulate the HTF in the circuit and start the anti-condensation protection;

Preferably, said step 1 specifically includes:

Step 11, set the initial conditions before adding HTF: connect one end of a flexible hose to the inlet of the HTF injection pump, and immerse the other end in the HTF barrel;

Step 12, start the self-priming HTF injection pump manually until the HTF in the HTF barrel is pumped or the expansion tank reaches the maximum allowable HTF injection volume;

Step 13, remove the moisture in the HTF, and the HTF is ready for use.

Preferably, said step 2 specifically includes:

Step 21, setting the initial conditions for preheating of a single test loop (16): before starting the preheating mode, connecting the single test loop (16) to the detection system through a pipeline containing a flexible hose;

Step 22, the control system (2) activates the preheating blower (12) and the third electric heater (10-3), so that the temperature reaches a set value, and exits from step 2;

Preferably, said step 3 specifically includes:

Step 31, making preparations for injecting HTF into the connected flexible hose and loop, including: connecting a flexible hose to the highest point exhaust port of a single detection loop, and connecting it to the HTF barrel;

Step 32, after the preparations are in place, open the highest point exhaust port valve of the single detection circuit, the control system (2) of the detection system starts to control the injection of air or inert gas into the expansion tank (7), and pushes the HTF slowly from a low position to a high position Fill the collector loop;

Step 33, after the HTF flows out through the highest point exhaust port of the single detection circuit and enters the HTF barrel, close the highest point exhaust port valve.

Preferably, said step 6 specifically includes:

Step 61, connect the cylinder outside the highest point exhaust port valve of the circuit, release the air or inert gas pressure to push the HTF back from the circuit to the detection system, wherein the detection system and the inlet and outlet valves of the single test circuit (16) are set to The inlet and outlet of the circuit are simultaneously opened and connected to the expansion tank, so that HTF enters the expansion tank (7), while air or inert gas finally enters the dissipative separation system (8);

Step 62, after emptying the HTF as much as possible, close the inlet and outlet valves of the detection system and the inlet and outlet valves of the loop, and then open the HTF outlet valve of the single test loop (16) to release the remaining HTF into the mobile medium collection tank;

Step 63, close the HTF discharge port valve and the highest point discharge port valve of the circuit, and disconnect the connection of the gas cylinder.

Preferably, the detection method further includes enabling the detection system to automatically enter an emergency protection mode and control the heat collector to turn to a safe position when the detection system is in defocus follow-up or encounters strong wind during the test step.

Beneficial effects of the present invention: the circuit performance detection system realizes multiple functions such as online debugging, online detection, mobile detection and other acceptance and operation and maintenance stages of the single circuit performance of the trough collector; through standard container type and modular structure design Form, taking into account the advantages of easy movement and large-scale production; the subsystems are independent of each other, and work together through the control system according to different test conditions, realizing the possibility of synchronously carrying out the overall construction of the trough-type solar thermal power station and the commissioning and acceptance of a single circuit; The flexible form of mobile detection can be used to quickly empty the heat transfer medium in a single circuit, greatly shortening the debugging cycle, improving the debugging efficiency, and reducing the testing cost; a complete sample data is formed for subsequent multi-island joint debugging and overall joint debugging of the power station When used in time, the uncertainty of the performance parameters of a single loop is reduced, and the joint debugging efficiency is improved.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are described below in detail with accompanying drawings.

Description of drawings

Fig. 1 is a structural diagram of a trough solar thermal power generation system according to the prior art.

Fig. 2 shows the structural principle of the circuit performance detection system of the trough-type photothermal power station according to the embodiment of the present invention.

Fig. 3 is a three-dimensional structure diagram of a circuit performance detection system of a trough-type photothermal power station according to an embodiment of the present invention.

Fig. 4 is a front view of a circuit performance detection system of a trough-type photothermal power station according to an embodiment of the present invention.

Fig. 5 shows the H-Q curve diagram of the circulation pump of the circuit performance detection system of the trough solar-thermal power station according to the embodiment of the present invention.

Wherein the reference signs represent respectively:

1-HTF system; 2-control system; 3-sensor system; 4-compressed air or inert gas system; 5-circulation pump; 6-cooling system; 7-expansion tank; 8-dissipative separation system; 9-HTF injection Pump; 10-1-first electric heater; 10-2-second electric heater; 10-3-third electric heater; 11-cyclone separation device; 12-preheating fan; 13-weather station; 14 -box; 15-piping system; 16-single test circuit

Detailed ways

See Figure 2 for the structural block diagram of the loop performance testing system of the trough-type photothermal power station, which is used to test the thermal performance of each loop. The entire system is equipped with corresponding equipment and pipelines, and the mobility and containers for the equipment and pipelines are also considered. , and obtained convenient and flexible detection characteristics. As shown in Figures 3 and 4, this embodiment provides a loop performance testing system for a trough-type photothermal power station. The testing system is connected to a single test loop (16) through a connecting pipe including a hose, and the testing systems are all installed in the box body 14. Inside, the box body 14 can be installed on a standard container frame car or a flatbed car, and can be dragged by the tractor head to move arbitrarily. The detection system includes:

HTF (heat transfer fluid) subsystem 1;

control system 2; and

sensor system 3;

Wherein the control system 2 sends a control signal to the HTF system 1 through the control wiring, so as to control the HTF system 1 to complete the cycle of HTF in the detection system and in the single test loop 16;

The sensor system 3 is respectively arranged at the expansion tank and the single test loop 16, and is used to collect data to analyze the performance of the single loop of the trough-type photothermal power station.

This embodiment also includes: a nitrogen system 4, the nitrogen system 4 includes a plurality of nitrogen cylinders, and multiple systems in the circuit performance detection system of the trough-type photothermal power station need to use nitrogen, such as the expansion tank 7, the cooling system 6, the circuit Heat system, circulation pump 5 and pipeline system 15 are used to seal the HTF system 1, maintain the pressure of the connected expansion tank 7, cooling system 6, loop preheating system, circulation pump, detection system pipeline and single test loop 16, and supply pressure to the single test loop 16. The test loop 16 is filled or emptied of HTF. Each nitrogen cylinder is equipped with a separate valve. The nitrogen cylinder is placed vertically upwards on the performance testing system and placed in the casing 14 . Considering the existence of extremely low temperature, the box body 14 is insulated and the first electric heater 10-1 is added to ensure that the surface temperature of the nitrogen cylinder reaches the minimum requirement. A manual chain hoist will be installed near the box body 14 to lift the nitrogen cylinder from the ground to the detection system. This hoist will be mounted on pulleys on a horizontal beam above the inspection system. Each cylinder also has an individual pressure regulator and is equipped with a check valve. It is estimated that the total gas consumption for testing a circuit is about 2000L, 200bar.

The main body of the HTF system 1 includes: a circulation pump 5; an expansion tank 7; and a cooling system 6, and a second electric heater 10-2 is also provided in this embodiment; wherein: the circulation pump 5 is used to drive the circuit performance of the trough-type photothermal power station For the circulation of HTF in the detection system and the single test circuit 16, the circulation pump 5 is set to provide the required flow and pressure difference in real time. According to the actual operating conditions of the project, this embodiment selects a commercially available heat transfer oil centrifugal pump, and the HQ curve of the centrifugal pump 5 in this embodiment is shown in Figure 5 . The expansion tank 7 is used for storing the HTF used for testing and absorbing excess expansion when the HTF is heated and expanded. The expansion tank in this embodiment is one 2m ³ , and the expansion tank 7 is installed horizontally, and after installation, it is connected to the compressed nitrogen system 4 to maintain the system pressure (4-13 bar). In this embodiment, the expansion tank 7 uses the same Therminol VP-1 heat transfer oil as in the single test circuit 16 as the HTF fluid. Of course, other common fluid forms that can be selected by those skilled in the art, or fluid forms selected according to the specific operating characteristics and requirements of the solar thermal power plant can also be selected, all within the protection scope of the present application. The operating temperature of the expansion tank 7 is 30-400°C. Manholes, HTF oil injection ports, N2 ports, emptying ports, backup ports, pressure indication ports, pressure sensing ports, temperature sensing ports, pressure relief valve ports and hydraulic ports are provided. Position indication/sensing interface, all interfaces are connected by flanges.

In this embodiment, the cooling system 6 adopts an air cooler, which is mainly used to dissipate the heat collected by the heat collector of the single test loop 16 . The purpose of adjusting the heat dissipation is achieved by adjusting the fan speed so that the outlet temperature meets the set requirements. Of course, in order to save the cost of the whole system, the cooling system 6 can also use water-cooling equipment, through the cooling water circulation cooling, by adjusting the cooling water flow to achieve the purpose of adjusting the heat dissipation so that the outlet temperature can meet the set requirements, only the volume of the performance testing system and Larger footprint.

The following formula shows the characteristics of the HTF corresponding to the air cooler adopted in the cooling system 6 at different temperatures:

Density (kg/m3)＝-0.9078*T(℃)+0.0004*T^2(℃)-2.3671*10^-6*T^3(℃)+1083.25

Heat capacity (kJ/kg*K)＝0.0024*T(℃)+5.9591*10^-6*T^2(℃)-2.9881*10^-8*T^3(℃)+4.4172*10^- 11*T^4(℃)+1.4982

Thermal conductivity (W/m*K)＝-8.1948*10^-5*T(℃)-1.9226*10^-7*T^2(℃)+2.5034*10^-11*T^3(℃ )-7.2974*10^-15*T^4(℃)+0.1377

kinematic viscosity

Enthalpy (kJ/kg)＝1.5113*T(℃)+1.2941*10^-3*T^2(℃)+1.2370*10^-7*T^3(℃)-0.6267

In this embodiment, one air cooler is to be selected for the performance testing system, the design ambient temperature is 0°C-45°C, the inlet temperature is 393°C and the outlet temperature is 293°C during operation. The number of built-in fans is 3.

The sensor system 3 includes a plurality of temperature sensors, pressure sensors, liquid level gauges and flow meters. The key temperature sensors include two, which are respectively arranged at the inlet and outlet of a single test loop 16 for measuring the temperature of the inlet and outlet of a single test loop 16. According to the inlet temperature Whether it is 0-450 degrees Celsius, whether the outlet temperature is 200-600 degrees Celsius to judge the performance of the solar thermal power generation system, the pressure sensor is installed in the expansion tank and the inlet and outlet of the single test circuit 16, respectively to measure the pressure in the expansion tank and the single test circuit The pressure value of 16 is used as an indicator of whether the expansion tank is working normally and the performance of the trough solar thermal power generation system; the liquid level gauge is set on the inner wall of the expansion tank to measure the liquid level of HTF in the expansion tank. When the liquid level is higher than the total height of the expansion tank 7 85%, the system alarm prompts oil discharge. When the liquid level is lower than the minimum liquid level requirement of the expansion tank 7, the system alarm prompts to replenish HTF in time; The pump and the control valve control the flow of HTF circulating in the HTF system and the single test loop 16, control the detection speed and ensure that the detection process is highly consistent with the actual working process of the trough solar power generation system. According to the inlet temperature of a single test loop 16 and the HTF flow in the loop, the light-to-heat conversion efficiency of the loop is calculated, and the calculation method of the light-to-heat conversion efficiency includes:

Among them, η——collector efficiency, ——Heat transfer oil flow rate, T _out ——loop outlet temperature, T _in ——loop inlet temperature, DNI——solar irradiance, A——loop mirror area.

The test system is equipped with a dissipative separation system 8, which includes a dissipative separation tank, which stores a certain amount of water inside and can separate the HTF contained in the tail gas discharged from the expansion tank 7 pressure relief valve interface pipe, dissipating When the separation system 8 is in working condition, its contents are water, HTF and its degradation products. In this embodiment, a 0.5m ³ dissipative separation tank is used. Unlike the expansion tank, the dissipative separation tank is directly connected to the external environment and does not require too high working pressure, so the operating pressure, internal design pressure and external design pressure are all selected as atmospheric pressure. The fluid in the dissipative separation tank is water, Therminol VP-1 and its degradation products, and the operating temperature range is 0-85°C. Similar to the design method of the expansion tank, the dissipative separation tank retains the manhole, the expansion tank interface, the atmospheric interface, the emptying interface, the water injection interface, the liquid level indicating interface, the liquid level sensing interface, the temperature indicating interface, the temperature sensing interface and Spare interface, each interface adopts the way of flange connection.

The performance detection system injects HTF into the performance detection system through the heat medium injection pump 9, which has the characteristics of using HTF as the medium and can run continuously. The heat medium injection pump 9 in this embodiment adopts a centrifugal oil injection pump that runs continuously. And adopt the self-priming exhaust pressure method, the intake pressure needs to be greater than 3bar, and the operating temperature is higher than 80°C.

The performance testing system realizes the internal connection of the performance testing system and the connection between the performance testing system and a single test circuit 16 through a complex pipeline system. The pipeline system can be divided into the following four subsystems according to its function and the medium passing through it:

The HTF pipeline subsystem is used to connect the HTF system 1 with other parts of the detection system;

The dissipation separation pipeline subsystem is used to connect the dissipation separation tank 8 with other parts of the detection system;

The expansion tank piping subsystem is used to connect the expansion tank 7 with other parts of the detection system. The connection between the expansion tank piping subsystem and the expansion tank 7 ensures tightness. It is preferably welded. If flanged connection is selected, it must be in accordance with ANSI Class 300 flanges, stainless steel and graphite spiral gaskets are required. These flange materials must be suitable for strong welding with tank materials to ensure welding operations when necessary;

The nitrogen pipeline subsystem is used to connect the nitrogen system 4 with other parts of the detection system;

The system installs the electric second heater 10-2 in the expansion tank 7 in a plug-in manner. In this embodiment, the second electric heater 10-2 is in the form of a thermal resistor, and the resistance value of the thermal resistor is related to the HTF characteristic. The reason why the second electric heater 10-2 is set is that under low or zero solar radiation intensity, the temperature of the heat transfer oil will continue to decrease due to atmospheric heat dissipation or other factors until the temperature at a certain point in the system reaches the condensation temperature of HTF ( 12°C). It is necessary to resolutely avoid the occurrence of solidification of the heat transfer oil, so the second electric heater 10-2 is used in the system to avoid the risk of solidification, and the second electric heater 10-2 sets HTF, which is the temperature of the heat transfer oil in this embodiment remain at a fixed value.

The first, second and third electric heaters 10-1, 10-2, 10-3 shall contain the necessary instrumentation to ensure that they operate correctly within the operating range shown in the corresponding data sheets, and the instrumentation includes temperature probes as a safety The elements, first, second and third electric heaters 10-1, 10-2, 10-3 also comprise a heating group with a control board allowing to receive signals from temperature probes for measuring the expansion tank 7 and/or the temperature of 16 measurement points in a single test loop, the temperature probe controls the start and stop of the thermal resistance under normal operation. In this embodiment, the temperature probe is selected from a thermocouple, and is equipped with a 4-20mA signal output. Of course, it can also be Other temperature sensor forms commonly used in the prior art are selected, such as thermistors, platinum resistors, and the like. The first, second and third electric heaters 10-1, 10-2, 10-3 are generally arranged horizontally, and are set by wrapping or inserting electric heating rods, with a power of 20kW and a voltage of 400V.

The system sets up a single test circuit preheating system to preheat the empty pipeline of the single test circuit 16, so as to avoid the HTF solidification caused by the low ambient temperature (the ambient temperature is, for example, 12 degrees Celsius) before the single test circuit 16 is filled with oil. The test loop preheating system uses the preheating blower 12 to make the nitrogen heated by the thermal resistance pass through the loop pipeline.

It also includes a cyclone separation device 11 arranged in a single test circuit 16. The cyclone separation device 11 is set so that when the nitrogen gas heated by the thermal resistance driven by the preheating fan 12 passes through the circuit pipeline, the HTF droplets present in the circuit flow with the air flow. Movement, using the filter and separator set in the cyclone separation device 11 to remove it before it reaches the preheating fan 12, the collected HTF is collected through the separator and then sent to the dissipation separation system 8 through an automatic valve or in a separate storage container.

The outside of the thermal resistance is provided with a sheath material formed of stainless steel or carbon steel with anti-corrosion function. The preheating fan 12 adopts a squirrel-cage type, 400Vac three-phase, 50hz, and the winding adopts a three-point star connection. The preheating motor 12 will be self-cooled by the fan connected to the shaft and the airflow flowing to the casing fins. The impeller and housing of the preheating fan 12 are single-stage, and its inlet and outlet can be guided to one side of the flange so as to be connected to the pipeline. The impeller is dynamically balanced when leaving the factory to avoid excessive vibration.

An anemometer is added at the top of the loop performance testing system to avoid sudden strong winds from damaging the heat collector on the single test loop 16 in the test.

The loop test system of the trough-type photothermal power station needs to be used in conjunction with the weather station 13. The weather station 13 is integrated with the loop test system of the trough-type photothermal power station or provided independently on site. The weather station 13 is used to record the environmental parameters required for the operation of the test system. The parameters mainly have two purposes: 1) determining the thermal performance of a single test loop 16; 2) loop safety under high irradiance and high wind speed. The control system of the weather station 13 collects the data information of each sensor in real time, and performs necessary processing. The weather station has enough memory to temporarily store the processed data for at least 48h with a time stamp.

Weather station 13 composition comprises in the present embodiment:

a) Anemometer

Cup Anemometer

Measuring range: 0.4m/s to 50m/s

Measurement initial threshold <0.5m/s

High linearity over operating range

Accuracy ±0.5m/s

b) Thermometer

Weather stations shall include temperature monitoring and temperature sensors shall:

·Low power consumption

· Easy on-site calibration

·Temperature measurement range: -40°C to 50°C

·Temperature measurement accuracy: ±0.2℃

·Temperature measuring element Pt 100

The sensor should be equipped with a protective cover to prevent solar radiation and precipitation

C) Solar pyranometer

·ISO9060 Standard: Level 1

·Detector Type: Thermopile

·Long-term stability <1%/year

Range: 0-2000W/m2

Spectral range (50% point): 285~2800nm

Field of view: 180°

· No power required

· Double glazed dome

·IP65

The specific method of using the circuit performance detection system of the trough-type photothermal power station for detection, including steps:

Step 1, HTF addition: add new HTF to the expansion tank, including:

Step 11, set the initial conditions before adding HTF: connect one end of a flexible hose to the inlet of the HTF injection pump, and immerse the other end in the HTF barrel;

Step 12, start the self-priming HTF injection pump manually until the HTF in the HTF barrel is pumped or the expansion tank reaches the maximum allowable HTF injection volume;

Step 13, remove the moisture in the HTF, and now the HTF is ready for use;

Step 2: Loop preheating: use nitrogen system 4, preheating blower 12 and third electric heater 10-3 to preheat single test loop 16 to increase the temperature of the loop to be tested. Too large will cause excessive thermal stress to a single test circuit 16 and damage the circuit components; specifically include:

Step 21, setting the initial conditions for preheating of the single test loop 16: before starting the preheating mode, connecting the single test loop 16 to the detection system through a pipeline containing a flexible hose;

Step 22, the control system 2 activates the preheating fan 12 and the third electric heater 10-3 to make the temperature reach the set value, and exit from step 2;

Step 3: Loop filling: Inject HTF into the connected piping with flexible hoses and into the loop to ensure that HTF does not freeze, thermal stress, and nitrogen bubbles remain in the loop; this includes:

Step 31, making preparations for injecting HTF into the connected flexible hose and loop, including: connecting a flexible hose to the highest point exhaust port of a single detection loop, and connecting it to the HTF barrel;

Step 32, after the preparation work is in place, open the highest point exhaust port valve of the single detection circuit, the control system 2 of the detection system starts to control the injection of nitrogen into the expansion tank 7, and pushes the HTF to slowly fill the collector circuit from the low position to the high position;

Step 33, after the HTF flows out through the highest point exhaust port of the single detection circuit and enters the HTF barrel, close the highest point exhaust port valve;

Step 4, focus tracking and testing: the collector continuously tracks the sun to focus, heats the HTF to a specified temperature, and records the output data of a single test loop 16 at each time, and then compares it with the DNI data at the corresponding time and performs a synchronous comparison. calculate;

Step 5: Loop cooling: Before performing the operation of emptying the HTF for the single test loop 16 and the detection system, the temperature of the HTF is rapidly cooled down through the cooling system;

Step 6: Drain the HTF: Drain the HTF in the single test loop 16, the flexible hose and the connecting pipe to complete the test of a loop, including:

Step 61, connect the nitrogen cylinder outside the exhaust port valve at the highest point of the loop, release the nitrogen pressure to push the HTF back from the loop to the detection system, wherein the inlet and outlet valves of the detection system and the single test loop 16 are set to open the loop inlet and outlet at the same time And connected to the expansion tank, so that the HTF enters the expansion tank 7, and the nitrogen finally enters the dissipative separation system 8;

Step 62, after emptying the HTF as much as possible, close the inlet and outlet valves of the detection system and the inlet and outlet valves of the loop, and then open the HTF oil outlet valve of the single test loop 16 to release the remaining HTF into the mobile medium collection tank;

Step 63, close the HTF oil discharge port valve and the highest point exhaust port valve of the circuit, and disconnect the connection of the gas cylinder.

In this embodiment, an ordinary protection step is added between step 3 and step 4, that is, the heat collector is turned to a safe position, the HTF in the loop is circulated and anti-condensation protection is started;

In this embodiment, the detection method further includes enabling the detection system to automatically enter an emergency protection mode and control the heat collector to turn to a safe position when the detection process is in defocus follow-up or encounters strong wind during the test step.

In this embodiment, the detection method further includes: the performance detection system is in the normal protection mode of step 4, and the heat collector is controlled to enter a position convenient for cleaning to enter the cleaning mode. Strong winds during the cleaning process will also prohibit the collector The heater rotates to ensure the safety of cleaning, including: when the wind speed is not high, the detection equipment controls the collector to enter the cleaning position, and starts the anti-condensation protection (the heat transfer oil is in a circulating state, the electric heater and electric heat tracing depend on the specific situation) open or close), the collector remains in the cleaning position, and any rotation operation of the collector is prohibited in the cleaning mode. In case of communication failure, strong wind or other emergency situations, the operator must manually end the cleaning mode after confirming that the cleaning personnel have left the cleaning area.

The single-loop detection system of this embodiment realizes multiple functions of heat collection loop debugging, performance testing, energy absorption improvement, and operation and maintenance, and realizes a modular structure design form, and the subsystems are independent of each other. Working together, the construction and commissioning of the trough-type photothermal power station are realized simultaneously, and the single-circuit rapid oil discharge shortens the commissioning cycle. The electric field is completely delivered to the joint debugging database, which reduces the volatility of the loop performance parameters and improves the joint debugging efficiency. The mobile detection is more flexible and reduces the detection cost.

While the invention has been described with reference to certain illustrative embodiments, it is not to be limited by these embodiments but only by the appended claims. Those skilled in the art should understand that changes and modifications can be made to the embodiments of the present invention without departing from the protection scope and spirit of the present invention.

Claims (20)

1. A trough-type photothermal power station circuit performance detection system, characterized in that: the detection system is connected to a single test circuit (16) through a pipeline, and the single test circuit (16) is isolated from other circuits, and the detection system is installed Inside the box (14), and being removable, includes: HTF system(1); control system (2); and sensor system (3); Wherein the control system (2) sends a control signal to the HTF system (1) through the control wiring to control the HTF system (1) to complete the detection of HTF in the detection system and in the single test loop (16). cycle; The measuring device of the sensor system (3) is arranged on the pipeline in the system, and is used to measure the flow rate and the inlet and outlet temperature of a single test loop (16), and is used to analyze the performance of a single loop of the trough-type photothermal power station, and at the same time Monitor each device in the detection system, so that the detection system can run safely and reliably. 2. The circuit performance detection system of a trough-type photothermal power station according to claim 1, further comprising: a compressed air or inert gas system (4), and the compressed air or inert gas system (4) is connected to Expansion tank (7), cooling system (6), loop preheating system and detection system piping, used to seal the HTF system (1), maintain the connected expansion tank (7), cooling system (6), loop preheating system, Circulation pump (5), pipeline system (15) and pressure of single test loop (16) and inject or empty HTF to single test loop (16). 3. The circuit performance detection system of a trough-type photothermal power station according to claim 2, characterized in that: the compressed air or inert gas system (4) includes one or more gas cylinders, each of the gas cylinders Equipped with a separate valve, the gas cylinder is placed vertically upward on the performance testing system, and placed in the box (14) or outside the box (14) near the box (14), each gas cylinder There is also a separate pressure regulator and is equipped with a check valve. 4. The circuit performance detection system of a trough-type photothermal power station according to claim 3, characterized in that: a gas cylinder heat insulation and heat preservation cabinet is arranged in the box body (14), and the heat insulation and heat preservation of the gas cylinder The first electric heater (10-1) is arranged outside the cabinet to heat the gas cylinder heat insulation cabinet, thereby ensuring that the surface temperature of the gas cylinder reaches the minimum requirement. There is a horizontal beam above the box (14), and the horizontal beam is set The pulley is equipped with a manual chain hoist to lift the gas cylinder from the ground to the performance testing system. 5. The circuit performance detection system of a trough-type photothermal power plant according to claim 1, characterized in that: the HTF system (1) includes a circulating pump (5), an expansion tank (7), Cooling system (6) and second electric heater (10-2); Wherein: The circulation pump (5) is used to drive the loop performance detection system of the trough-type photothermal power station and the circulation of HTF in the single test loop (16), and the circulation pump (5) provides the required flow and pressure difference in real time; The expansion tank (7) is used to store the HTF used for testing and absorb volume expansion when the HTF is heated and expanded. The expansion tank (7) is installed horizontally and is connected with the compressed air or inert gas system (4) to maintain the pressure of the system scope; The cooling system (6) is an air cooler or a water cooler, which is used to dissipate the heat collected by a single test circuit (16), and adjust the heat dissipation by adjusting the fan speed of the air cooler or the cold water flow of the water cooler The purpose is to make the outlet temperature meet the set requirements; The second electric heater (10-2) is arranged on the pipeline (1) of the HTF system, the second electric heater (10-2) is in the form of a thermal resistance, and the resistance value of the thermal resistance is Related to the HTF characteristics and pipeline heat dissipation characteristics, the second electric heater (10-2) is used to maintain the temperature of the HTF in an appropriate range, and the second electric heater (10-2) contains instruments to ensure that it is in the corresponding correct operation within the operating range shown in the data sheet, the meter includes a temperature probe as a safety element, and the second electric heater (10-2) also includes a heating group with a control board that allows receiving from The signal of the temperature probe, the temperature probe is used to measure the temperature of the measurement point in the HTF system (1), and the temperature probe controls the start and stop of the thermal resistance under normal operation. 6. The circuit performance detection system of a trough-type photothermal power station according to claim 1, characterized in that: the sensor system (3) includes a temperature sensor, a flow meter, a pressure sensor and a liquid level gauge, and the temperature sensor Including at least two, respectively arranged at the inlet and outlet of the single test circuit (16), for measuring the temperature of the inlet and outlet of the single test circuit (16); the flowmeter is arranged at the outlet of the control valve arranged downstream of the circulating pump, The control system controls the flow of HTF circulating in the HTF system and the single test circuit (16) by adjusting the circulation pump and the control valve, controls the detection speed and ensures that the detection process is consistent with the actual working process of the trough solar power generation system, according to the single test The temperature of the inlet and outlet of the circuit (16) and the HTF flow in the circuit are calculated to obtain the thermal power of the circuit; part of the pressure sensor is arranged in the expansion tank and at the inlet and outlet of the single test circuit (16), respectively measuring The pressure in the expansion tank and the pressure value of a single test circuit (16) are used to judge whether the monitoring system and the single test circuit (16) are operating normally; the liquid level gauge is arranged on the expansion tank to measure the liquid level of HTF in the expansion tank. When the liquid level is higher than 85% of the total height of the expansion tank (7), the system alarm prompts to discharge HTF; when the liquid level is lower than the minimum allowable liquid level of the expansion tank (7), the system alarm prompts to replenish HTF in time. 7. A trough-type photothermal power plant circuit performance detection system according to claim 1, characterized in that it also includes: a dissipation separation system (8), and the dissipation separation system (8) includes a dissipation separation tank, It stores a certain amount of water inside, which can separate the HTF contained in the tail gas discharged from the expansion tank (7) pressure relief valve interface pipe and the degradation products produced by high temperature cracking. When the dissipation separation system (8) is in working condition , the contents of which are water, HTF and the degradation product, and the dissipation separation tank is directly communicated with the external environment. 8. The loop performance detection system of a trough-type photothermal power station according to claim 1, characterized in that it also includes an HTF injection pump (9) for injecting HTF into the performance detection system, and the HTF injection The pump (9) has the characteristic of using HTF as the medium and being able to run continuously. 9. A trough-type photothermal power plant loop performance testing system according to claim 2, characterized in that: the pipeline system (15) is used for the internal connection of the performance testing system and the performance testing system and a single test loop (16) The connection between the pipeline system (15) can be divided into the following four subsystems according to its function and the medium passing through it: The HTF pipeline subsystem is used to connect the HTF system (1) with other parts of the detection system; The dissipation separation pipeline subsystem is used to connect the dissipation separation tank (8) with other parts of the detection system; The expansion tank piping subsystem is used to connect the expansion tank (7) to other parts of the detection system, and the expansion tank piping subsystem is sealed to the expansion tank (7); The gas pipeline subsystem is used to connect the compressed air or inert gas system (4) with other parts of the detection system. 10. A loop performance testing system for a trough-type photothermal power plant according to claim 7, characterized in that it also includes a single test loop preheating system consisting of a preheating fan (12) and a third electric heater (10-3). The heating system is used to preheat the empty pipeline of the single test loop (16), so as to avoid HTF solidification due to the low temperature of the pipeline before the HTF injection of the single test loop (16), and the single test loop preheats the system The air or inert gas heated by the third electric heater (10-3) passes through the loop pipeline to achieve the purpose of preheating through the preheating blower (12). 11. The circuit performance detection system of a trough-type photothermal power station according to claim 10, characterized in that it also includes a cyclone separation device (11) arranged in a single test circuit (16), and the cyclone separation device (11) is arranged ) makes the air or inert gas heated by the thermal resistance driven by the preheating fan (12) pass through the loop pipeline, the HTF droplets present in the loop move with the air flow, and the filter set in the cyclone separation device (11) is used to The separator and the separator are removed before it reaches the preheating fan (12), and the collected HTF is collected by the separator and then sent to the dissipation separation system (8) or a separate storage container through an automatic valve. 12. A loop performance testing system for a trough-type photothermal power plant according to claim 1, characterized in that the loop performance testing system is equipped with an anemometer, which is installed on the top of the testing system or at a certain height near it to measure the wind speed and transmit into the control system (2), avoiding sudden strong winds during the test from damaging the heat collector on the single test loop (16). 13. The circuit performance detection system of a trough-type photothermal power station according to claim 1, characterized in that the circuit test system of the trough-type photothermal power station is used in conjunction with a weather station (13), and the weather station (13) is at least Including: anemometer, temperature and humidity meter and solar irradiance meter, the weather station (13) is integrated by the loop test system or provided independently by the site, the weather station (13) is used to record the environmental parameters required for the operation of the test system, said The environmental parameters are used to determine the thermal performance of a single test circuit (16); and to ensure the safety of the circuit under high irradiance and high wind speed, the control system of the weather station (13) collects the data information of each sensor in real time and performs data information processing. 14. A loop performance detection method using the loop performance detection system of a trough-type photothermal power station according to any one of claims 1-13, characterized in that it comprises the steps of: Step 1, HTF addition: add new HTF to the expansion tank; Step 2: loop preheating: use compressed air or inert gas system (4), preheating fan (12) and third electric heater (10-3) to preheat a single test loop (16) to increase the temperature of the loop to be tested , so as to prevent the HTF from solidifying or damage the circuit components due to excessive thermal stress on a single test circuit (16) due to an excessive temperature difference; Step 3: Injection of HTF into the circuit: Inject HTF into the connecting pipes and circuits with flexible hoses, ensuring to avoid HTF solidification, thermal stress and residual air or inert gas bubbles in the circuit; Step 4, focus tracking and testing: the collector continuously tracks the sun to focus, heats the HTF to a specified temperature, and records the output data of a single test loop (16) at each time, and then compares it with the DNI data at the corresponding time and perform calculations; Step 5: loop cooling: before the single test loop (16) and the detection system are emptied of the HTF, the temperature of the HTF is cooled down rapidly through the cooling system; Step 6: Empty the HTF: Empty the HTF in the single test loop (16), the flexible hose and the connecting pipe to complete the test of one loop. 15. The method according to claim 14, characterized in that between said step 3 and step 4, further comprising: Normal protection: turn the collector to a safe position, circulate the HTF in the circuit and activate the anti-condensation protection. 16. The method according to claim 14, characterized in that said step 1 specifically comprises: Step 11, set the initial conditions before adding HTF: connect one end of a flexible hose to the inlet of the HTF injection pump, and immerse the other end in the HTF barrel; Step 12, start the self-priming HTF injection pump manually until the HTF in the HTF barrel is pumped or the expansion tank reaches the maximum allowable HTF injection volume; Step 13, remove the moisture in the HTF, and the HTF is ready for use. 17. The method according to claim 14, characterized in that said step 2 specifically comprises: Step 21, setting the initial conditions for preheating of a single test loop (16): before starting the preheating mode, connecting the single test loop (16) to the detection system through a pipeline containing a flexible hose; Step 22, the control system (2) activates the preheating fan (12) and the third electric heater (10-3) to make the temperature reach the set value, and exit from step 2. 18. The method according to claim 14, characterized in that said step 3 specifically comprises: Step 31, making preparations for injecting HTF into the connected flexible hose and loop, including: connecting a flexible hose to the highest point exhaust port of a single detection loop, and connecting it to the HTF barrel; Step 32, after the preparations are in place, open the highest point exhaust port valve of the single detection circuit, the control system (2) of the detection system starts to control the injection of air or inert gas into the expansion tank (7), and pushes the HTF slowly from a low position to a high position Fill the collector loop; Step 33, after the HTF flows out through the highest point exhaust port of the single detection circuit and enters the HTF barrel, close the highest point exhaust port valve. 19. The method according to claim 14, characterized in that said step 6 specifically comprises: Step 61, connect the cylinder outside the highest point exhaust port valve of the circuit, release the air or inert gas pressure to push the HTF back from the circuit to the detection system, wherein the detection system and the inlet and outlet valves of the single test circuit (16) are set to The inlet and outlet of the circuit are simultaneously opened and connected to the expansion tank, so that HTF enters the expansion tank (7), while air or inert gas finally enters the dissipative separation system (8); Step 62, after emptying the HTF as much as possible, close the inlet and outlet valves of the detection system and the inlet and outlet valves of the loop, and then open the HTF outlet valve of the single test loop (16) to release the remaining HTF into the mobile medium collection tank; Step 63, close the HTF discharge port valve and the highest point discharge port valve of the circuit, and disconnect the connection of the gas cylinder. 20. The method according to claim 14, characterized in that the detection method also includes making the detection system automatically enter the emergency protection mode when the detection process is in defocus follow or encounters strong wind during the test step, and controls the heat collector to rotate to a safe location.