A method for testing and correcting temperature deviation of heat receiver under non-ideal working condition

Abstract

The application discloses a heat receiver thermal efficiency test and temperature deviation correction method under non-ideal working conditions and belongs to the technical field of solar thermal power generation. The application introduces DNI deviation correction in the mirror field grouping method so as to relax the test time window or allow cross-day test under the premise of ensuring test accuracy. First, the thermal power test under the half-mirror field heliostat is performed to determine the highest operating temperature actually reached under the minimum safe flow as the reference temperature T A ; then the thermal power test under the full-mirror field heliostat is performed, the measured DNI and thermal power are substituted into the calculation, and the heat receiver efficiency under the reference temperature T A is obtained. If the reference temperature T A cannot reach the design value, the test-based temperature correction method does not require a heat loss physical model, is simple to operate and easy to implement in engineering.

Description

Technical Field

[0001] This invention relates to the field of solar thermal power generation technology, specifically to a method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations. Background Technology

[0002] A tower-type concentrated solar power (CSP) system consists of a heliostat field, a receiver, a thermal storage system, and power generation units. The receiver converts solar energy into heat, absorbing and transferring the solar radiation reflected and focused by the heliostat field to an internal heat transfer medium (usually molten salt). This heat transfer medium is then heated to its design temperature and stored in a thermosalt tank to drive a steam turbine generator set for power generation. The thermal efficiency of the receiver directly determines the proportion of solar energy collected by the heliostat field that is actually converted into usable heat energy, affecting the overall power plant's power generation efficiency and return on investment.

[0003] The thermal efficiency of a receiver is defined as the ratio of the output heat power of the working fluid through the receiver to the total solar radiation power projected onto the receiver's light-collecting opening, i.e.: (1) In the construction and daily operation and maintenance of commercial concentrated solar power (CSP) plants, the performance testing of the receiver is a crucial step in the project's final acceptance and a routine but important inspection during daily operation and maintenance. It is primarily used to confirm whether the receiver's thermal efficiency under actual operating conditions is close to the design value stipulated in the equipment supply contract.

[0004] Currently, the main basis for testing the thermal efficiency performance of receivers in my country is the national recommended standard GB / T 41307-2022, "Test Methods for Receivers of Tower Solar Thermal Power Plants." This standard specifies the mirror field grouping method as one of the efficiency testing methods. The core idea of ​​the mirror field grouping method is to decouple the receiver efficiency by changing the number of heliostats in operation, avoiding the difficulty in accurately obtaining the total incident energy of the receiver through direct measurement. The specific operating steps are as follows: The first step is to determine the setpoint for the receiver outlet temperature based on standard operating conditions and complete the grouping of heliostats. The second step, under stable meteorological conditions, is to initially operate only half-field heliostats (referred to as operating condition A). After the receiver reaches thermal equilibrium, the receiver's output power is measured and recorded. P out,A The third step, with DNI and weather conditions remaining stable, is to quickly switch to full-field heliostat operation (referred to as operating condition B), and measure the output power of the receiver again. P out,B The fourth step is to calculate the receiver efficiency based on the two power measurements. The formula for calculating the receiver thermal efficiency under operating condition B is as follows: (2) in, αThis represents the absorption ratio of the heat absorber.

[0005] Based on the controlled variable method, to accurately measure the receiver thermal efficiency under condition B, the following core requirements must be met: First, the molten salt outlet temperature of the receiver under both conditions A and B should be adjusted to the design value and kept stable; second, the DNI (Digital Nucleus Intake) should remain basically stable during the testing period under both conditions; and third, losses such as cosine loss and reflection loss should remain stable. Therefore, relevant standards require the following testing requirements: the test time should preferably be between 11:20 and 12:40 local true solar time. This is because, under clear weather conditions, the DNI value is relatively high and basically stable during this test window, and the cosine loss is low and remains stable. Two prominent problems with existing methods in engineering applications are as follows: Question 1: The outlet temperature sometimes fails to reach the design value. This is one of the problems encountered in the actual testing of the mirror field grouping method, mainly in the half-mirror field heliostat operation condition (condition A). When only 50% of the heliostats are in operation, due to equipment defects or operational limitations, the incident solar radiation energy received by the receiver is about half of that under the design condition. To ensure that the outlet temperature still reaches the design value, the molten salt flow rate needs to be reduced to a certain low value. However, in actual engineering, each absorber tube in the receiver has a strict minimum safe flow rate limit. The minimum safe flow rate limit is to ensure that the molten salt in the absorber tube can provide sufficient convective cooling capacity under any operating condition, preventing the tube wall from overheating or even burning due to excessively high local heat flux density. The minimum safe flow rate is usually determined by factors such as the absorber tube material, tube diameter, wall thickness, design heat flux density distribution, and the maximum allowable temperature of the tube wall. When condition A requires the flow rate to be reduced to the required low value, this value may already be below the minimum safe flow rate limit, so operators cannot continue to reduce the flow rate to achieve the target outlet temperature. Meanwhile, the inlet molten salt temperature of the receiver is usually determined by the upstream cold salt storage tank, and is constrained by the overall thermal storage system and steam generation system, so it cannot be arbitrarily adjusted independently during production operation. The combination of these two physical constraints means that when 50% of the mirror field is operational, the molten salt outlet temperature may be lower than the design value, with deviations reaching 20℃ to 60℃. The standard clearly requires the molten salt outlet temperature to reach the design value, but does not provide a correction method when physical constraints prevent the temperature from meeting the standard.

[0006] Furthermore, in certain situations (such as when solar radiation conditions are poor), even under full-field heliostat operation, the exit temperature may not reach the design value, which existing methods also cannot handle.

[0007] Question 2: The test window of the mirror field grouping method is relatively short, and the direct normal irradiance (DNI) of the sun varies greatly outside the window. The standard GB / T 41307-2022, "Test Method for Absorbers of Tower Solar Thermal Power Plants," stipulates that the test time should be between 11:20 and 12:40 local true solar time. This requirement is extremely stringent in actual open-air testing. First, solar radiation is dominated by natural weather conditions and is inherently uncontrollable. Even in clear weather observed by the naked eye, thin clouds at high altitudes, changes in aerosol concentration, and dust can cause short-term fluctuations in DNI. A thin cirrus cloud that cannot be detected by the naked eye can cause a 3% to 5% decrease in DNI. Second, switching from operating condition A to operating condition B requires switching thousands of heliostats in group B to sun-tracking mode one by one, adjusting their attitude to aim at the absorber, waiting for stable energy projection, and then waiting for the tube wall temperature field to re-establish thermal equilibrium. The entire process may take 15 to 30 minutes. During this period, the solar altitude angle itself is also constantly changing, causing changes in cosine efficiency. Even without cloud cover, the natural changes in the sun's position are enough to introduce a systematic deviation in incident energy between the two operating conditions. Therefore, the assumptions that the test should be conducted between 11:20 and 12:40 local true solar time and that the DNI should remain consistent under operating conditions A and B are difficult to strictly meet in practice. If the test conditions cannot be met, the test data will be deemed invalid, and the test must wait for the next meteorological window. In actual engineering projects, it is not uncommon for the commissioning or testing cycle to be extended to several weeks or even months due to the scarcity of meteorological windows.

[0008] Currently, there is a lack of systematic solutions in the industry for the two non-ideal factors mentioned above. Regarding temperature deviation, a few studies have proposed correction methods based on physical models of heat loss, which require pre-calibration of radiation and convection heat loss coefficients. The calibration process relies on incident power data that is difficult to obtain accurately and involves nonlinear fitting, making it impractical in engineering settings. For the problem of short test windows in the mirror field grouping method and significant DNI variations outside the window, some engineering practices have mitigated the impact by shortening the switching time, but this cannot fundamentally eliminate the problem. Existing technologies have not yet provided a unified testing and correction scheme that can simultaneously address exit temperature deviation (including situations where even 100% of the mirror field fails to reach the design temperature) and DNI fluctuations. Summary of the Invention

[0009] To address the aforementioned issues, this invention provides a method for testing the thermal efficiency of receivers under non-ideal operating conditions and correcting temperature deviations. It introduces a correction for DNI deviation in the mirror field grouping method, allowing for a wider testing time window or enabling cross-day testing while maintaining testing accuracy. This solves the problems of short testing windows, significant DNI variations outside the window, and the inability to reach the design value of the molten salt outlet temperature under half-field heliostat conditions and potentially under full-field heliostat conditions. This method does not rely on complex heat loss physical model calibration, is simple to operate, has a transparent correction path, and can handle situations where the design temperature cannot be directly reached.

[0010] To achieve the above objectives, the present invention provides a method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting for temperature deviations, comprising the following steps: Perform thermal power tests under half-field heliostat conditions to determine the reference temperature T under these conditions. A ; Perform a thermal power test under full-field heliostat operating conditions to obtain the reference temperature T. A The heat output power P of the heat absorber below out,B and the corresponding normal direct irradiance DNI B ; According to the reference temperature T A The heat output power P of the heat absorber below out,B The corresponding normal direct irradiance DNIB, the receiver output heat power Pout,A under the half-field heliostat condition, and the corresponding normal direct irradiance DNI. A Calculate the reference temperature T A The thermal efficiency η of the heat absorber below B ; If the reference temperature T A If the temperature is lower than the molten salt outlet design temperature, a molten salt outlet temperature correction is performed to obtain the absorber thermal efficiency at the design temperature.

[0011] Furthermore, the thermal power test performed under the half-field heliostat operating condition is used to determine the reference temperature T under the half-field heliostat operating condition. A The steps include: A thermal power test was performed on the heliostat under the operating conditions of a half-field mirror, and the highest outlet temperature that the receiver could actually reach when operating at a preset minimum safe flow rate was used as the reference temperature T. A .

[0012] Furthermore, the heat output power of the heat absorber is calculated using the following formula: P out = ×c p ×(T out T in ) in, cp is the molten salt mass flow rate, cp is the average specific heat capacity of the molten salt, and T is the molten salt mass flow rate. in T represents the inlet temperature of the receiver. out This is the outlet temperature of the absorber.

[0013] Furthermore, the receiver thermal efficiency under operating condition B or B for:

[0014] In the formula, k =0.5 and P loss,B - P loss,A =0, if the DNI is inconsistent between the half-field heliostat operating condition and the full-field heliostat operating condition. k for: .

[0015] Furthermore, the process of correcting the molten salt outlet temperature includes: If the design temperature can be reached under the full-field heliostat operating conditions, a thermal power test at the design temperature will be performed to obtain the receiver output thermal power at the design temperature. The thermal efficiency of the receiver at the design temperature is calculated according to the following formula. :

[0016] The output power of the receiver under operating condition B, Thermal efficiency of the receiver under operating condition B.

[0017] Furthermore, if the design temperature cannot be reached under the full-field heliostat operating conditions, thermal power tests are performed at multiple different outlet temperatures to establish the correspondence between the molten salt outlet temperature and the receiver thermal power ratio. The receiver thermal efficiency at the design temperature is then extrapolated, where the receiver thermal power ratio is... ,in The heat output power of the absorber at the i-th outlet temperature.

[0018] Furthermore, the molten salt flow rate in the half-field heliostat operation is not lower than the minimum safe flow rate of the receiver, and the molten salt outlet temperature in the full-field heliostat operation is adjusted to the reference temperature T. A .

[0019] Furthermore, when performing multiple thermal power tests at different outlet temperatures under the full-field heliostat operating conditions, the molten salt outlet temperature is controlled by adjusting the molten salt flow rate, which is not lower than the minimum safe flow rate and not higher than the design maximum flow rate.

[0020] Furthermore, the relationship between the molten salt outlet temperature and the absorber heat power ratio is fitted as a first-order polynomial or a second-order polynomial.

[0021] The above-mentioned method for testing the thermal efficiency of receivers under non-ideal operating conditions and correcting temperature deviations is applied to the testing of the thermal efficiency of receivers under non-ideal operating conditions and the correction of temperature deviations.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The solution described in this invention can flexibly cope with various non-ideal temperature conditions. First, the reference temperature under the half-field heliostat condition is determined through a half-field heliostat test. Then, the absorber thermal efficiency at the reference temperature is measured under the full-field heliostat condition. If the molten salt outlet temperature can reach the design temperature under the full-field heliostat condition, it is directly corrected. If not, it is corrected by extrapolation at multiple temperature points. This solves the problem that the standard method cannot be tested when the outlet temperature does not reach the design value (including under the full-field heliostat condition).

[0023] Introducing DNI bias correction into the mirror field grouping method allows for a wider testing time window or allows for cross-day testing while ensuring testing accuracy. It does not rely on complex physical models of heat loss. The correction process is based solely on measured power, temperature, flow rate, DNI, and area. It extrapolates the ratio of specific power, making it simple to operate and easy to implement in engineering. Each calculation step is clearly defined, the extrapolation process is supported by data, and the results are verifiable, making it suitable for performance evaluation tests with high reliability requirements. Attached Figure Description

[0024] Figure 1 This is an overall flowchart of the method of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The first step is to conduct a thermal power test under half-field heliostat conditions (50% of the field of view) to determine the highest operating temperature that can actually be achieved when the half-field heliostat is put into operation, and use this temperature as the reference temperature. T A Thermal power tests and DNI tests were performed under two conditions, Condition A and Condition B, for the heliostat with a half-field field. Condition A was used for the heliostat with a full-field field, and Condition B was used for the heliostat with a full-field field. The thermal power of the heliostat under Condition A (half-field field) can be measured. P out,A and DNI A And the thermal power under the full-field heliostat operating condition (condition B). P out,B and DNI B .

[0027] According to the energy conservation equation, the energy under operating conditions A and B satisfies the following equation: (3) In the formula, P in,A , P out,A and P loss,A These are, respectively, the total solar radiation power projected onto the receiver's light-collecting port under operating condition A, the receiver's output power, and the energy loss, in MW; P in,B , P out,B and P loss,B These are the total solar radiation power projected onto the receiver's light-collecting port under operating condition B, the receiver's output power, and the energy loss. α It is the absorptivity of the surface of the light-collecting port of the heat absorber.

[0028] According to equation (3), the thermal efficiency of the receiver under operating condition B is... or B Represented as: (4) (5) According to the national standard GB / T 41307-2022 "Test Method for Absorbers of Tower Solar Thermal Power Plants", when using the mirror field grouping method, the formula for calculating the thermal efficiency of the absorber under operating condition B is shown in equation (2), which can be considered as follows: k =0.5 and P loss,B - P loss,A =0. If the DNI is inconsistent under the half-field heliostat operating condition (condition A) and the full-field heliostat operating condition (condition B), k Pick: (6) The second step, if the reference temperature T A If the design value is not reached, a correction of the molten salt outlet temperature is performed. Under full-field heliostat operation, due to the relatively abundant incident energy, large flow rate adjustment range, and short adjustment time, receiver thermal power tests at different molten salt outlet temperatures can be conducted. If the design temperature can be directly reached, a design temperature test (condition C) can be performed to obtain the thermal power at the design molten salt outlet temperature. P out,C If the incident energy can be kept constant under operating conditions B and C, then the thermal efficiency of the receiver under operating condition C can be expressed as (the ratio of efficiencies equals the ratio of specific power): (7) If the design temperature still cannot be reached, perform multiple thermal power tests at different outlet temperatures to establish the molten salt outlet temperature - absorber thermal power ratio. The relationship is used to extrapolate the absorber thermal efficiency at the design temperature. P out,Ci This indicates the heat output of the absorber at different molten salt outlet temperatures.

[0029] Detailed steps for testing and revising the plan: Step S1: Perform a thermal power test under half-field heliostat operating conditions to determine the reference temperature under half-field heliostat operating conditions. T A ; According to the national standard GB / T 41307-2022 "Test Method for Absorbers of Tower Solar Thermal Power Plants", the heliostat field is divided into two groups, A and B. Initially, only the heliostats in group A (half-field) will be put into operation. The molten salt flow rate is set not lower than the minimum safe flow rate of the absorber. The heliostat pointing strategy remains consistent with all subsequent operating conditions.

[0030] Under these conditions, the receiver is operated until thermal equilibrium is reached, and the following parameters are collected simultaneously: Direct Normal Irradiance (DNI). A molten salt mass flow rate A Heat absorber inlet temperature T in,A and import pressure p in,A Heat absorber outlet temperature T out,A and export pressure p out,A .

[0031] Calculate the receiver output power under operating condition A. P out,A The average specific heat capacity of the molten salt is taken between the inlet and outlet temperatures and pressures. . P out,A Calculate using the following formula: (8) The outlet temperature obtained under this operating condition T out,A That is, the reference temperature T A If the flow rate is set to the minimum safe flow rate, then it represents the highest operating temperature that can actually be achieved under the condition of a half-field heliostat. T A Below the design temperature of the molten salt outlet.

[0032] Step S2: Perform the full-field heliostat reference condition test; After step S1, switch to simultaneous operation of both Group A and Group B as soon as possible. During the switchover, the heliostat pointing strategy remains unchanged, and the molten salt outlet temperature is adjusted by regulating the molten salt flow rate.T A .

[0033] Under these conditions, the receiver is operated until thermal equilibrium is reached, and all parameters identical to those in step S1 are collected. The normal direct irradiance (DNI) is recorded. B molten salt mass flow rate B Heat absorber inlet temperature T in,B and import pressure p in,B Heat absorber outlet temperature T out,B and export pressure p out,B Calculate the receiver output power under full-field heliostat operating conditions. P out,B .

[0034] Step S3: Calculate the reference temperature T A The thermal efficiency of the heat absorber is as follows or B ; Step S4: If the reference temperature T A Below the molten salt outlet design temperature, a full-field heliostat thermal power test was performed to obtain the molten salt outlet temperature - absorber thermal power ratio. P out,Ci / P out,B The relationship between the molten salt outlet temperature and the absorber heat power ratio can be fitted as a first-order polynomial or a second-order polynomial.

[0035] With the full-field heliostat in operation, the molten salt inlet temperature remains constant, and the heliostat pointing strategy remains the same. Since the incident energy is relatively abundant at this point, the flow rate can be adjusted within a safe range. Although the incident DNI (Discharge Noise Level) is also required to remain essentially constant, different molten salt outlet temperatures are easily obtained due to the shorter time required for temperature adjustment. T Ci thermal power P out,Ci This step is performed in two scenarios.

[0036] Scenario 1: The heliostat can reach the design temperature under full-field operating conditions. If adjusting the molten salt flow rate (not lower than the minimum safe flow rate, not higher than the design maximum flow rate) allows the molten salt temperature at the receiver outlet to reach the design temperature and remain stable, then perform a thermal power test at the design temperature. Let this operating condition be condition C, and record the following parameters: Normal direct irradiance (DNI). C molten salt mass flow rate C Heat absorber inlet temperature T in,C and import pressure p in,C Heat absorber outlet temperature T out,C and export pressure p out,C Calculate the receiver output power under operating condition C. P out,C The thermal efficiency of the receiver under operating condition C can be expressed as equation (7).

[0037] Scenario 2: The design temperature cannot be reached under full-field heliostat operating conditions. If the molten salt outlet temperature still cannot reach the design temperature under full-field heliostat conditions (e.g., due to persistently low DNI or equipment defects), then at least three sets of thermal power tests with different outlet temperatures must be performed under full-field heliostat conditions to obtain at least three sets of molten salt outlet temperature - absorber thermal power ratios. P out,Ci / P out,B The data points are extrapolated to obtain the receiver thermal efficiency at the design temperature.

[0038] Step S6: Output the final result.

[0039] Example: Performance test of the receiver of a 100MW tower molten salt solar thermal power plant A commercial tower-type concentrated solar power (CSP) plant is designed to generate 100MW of electricity. The receiver is an externally mounted cylindrical molten salt receiver with a designed outlet temperature of 565.0℃, a designed molten salt flow rate of 700.0 kg / s, and a designed inlet temperature of 290.0℃. The working fluid is solar salt (60% NaNO3 + 40% KNO3). The heliostat field consists of 20,000 heliostats, each with a single-mirror reflecting area of ​​30m². 2 The total reflective area is 600,000 m². The mirror field is divided into two groups, A and B, according to the mirror field grouping method in the national standard GB / T41307-2022 "Test Method for Absorbers of Tower Solar Thermal Power Plants". The minimum safe flow rate of the absorber tube is 360.0 kg / s (60% of the design flow rate). The temperature of the cold salt tank is maintained at 290.0 ± 5℃ and cannot be adjusted during the test. Absorption ratio... α * The design value is taken as 0.96. The average specific heat capacity of molten salt in the range of 290℃ to 565℃ is approximately 1516.5 J / (kg·℃). The thermal efficiency of the receiver at an outlet temperature of 565℃ was tested as follows: Step S1: Conduct a thermal power test under half-field heliostat conditions to determine the reference temperature under half-field heliostat conditions. Only 50% of the mirror field was operational, with the flow rate set at 310.0 kg / s (minimum safe flow rate), inlet temperature not adjusted, and the pointing strategy using a standard multi-target point uniform distribution. Data was recorded after 15 minutes of stable operation: Direct Normal Irradiance (DNI). A =910.0W / m 2 ; Absorber inlet molten salt temperature T in,A =290.0℃; Absorber outlet temperature T out,A =540.0℃; taking the average specific heat capacity of molten salt between 290.0 and 540.0℃ as 1514.4 J / (kg·℃), calculate the output power of the absorber: P out,A =310.0×1514.4×(540.0 290.0) = 117.37MW The outlet temperature under this operating condition is 540.0℃, which is the reference temperature, 25.0℃ lower than the design temperature of 565℃.

[0040] Step S2: Thermal power test under full-field heliostat operating conditions (reference temperature 540℃) Switch to full-field operation, do not adjust the inlet temperature, and adjust the outlet temperature to 540℃. After 15 minutes of stable operation, record the following data: flow rate = 642.0 kg / s, normal direct irradiance (DNI). B =880W / m²; Absorber inlet molten salt temperature T in,A =290.0℃; Absorber outlet temperature T out,A =540.0℃; taking the average specific heat capacity of molten salt between 290.0 and 540.0℃ as 1514.4 J / (kg·℃), calculate the output power of the absorber: P out,B =642.0×1514.4×(540.0 290.0) = 243.06MW Step S3: Calculate the efficiency at the reference temperature of 540℃ or B : or B =(1 0.5×910.0 / 880.0)×0.96×243.06 / (243.06 117.37) = 89.7% Step S4: Thermal power test under full-field heliostat operating conditions (able to reach the design temperature) Switch to full mirror field operation, maintain flow rate at 580.0 kg / s, inlet temperature unchanged, outlet temperature adjusted to 565℃. After 15 minutes of stable operation, record the following data: Solar Direct Normal Irradiance (DNI). B =875W / m² (ignoring variations); molten salt temperature at the absorber inlet T in,A =290.0℃; Absorber outlet temperature T out,A =565.0℃; taking the average specific heat capacity of molten salt between 290.0 and 565.0℃ as 1516.5 J / (kg·℃), calculate the output power of the absorber: P out,C =580.0×1516.5×(565.0 290.0) = 241.88MW Calculate the corrected efficiency: or C =89.7% × 241.88 / 243.06 = 89.2% Step S5: Output the result.

[0041] This invention is applicable to the following non-ideal operating conditions: when all tests cannot be completed within the test window of the mirror field grouping method, and when the DNI changes significantly outside the window; and when the outlet temperature of the heliostat under half-field conditions cannot reach the design value due to the minimum safe flow limit of molten salt, or even under full-field conditions, the outlet temperature may not reach the design value.

[0042] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting for temperature deviation, characterized in that, Includes the following steps: Perform thermal power tests under half-field heliostat conditions to determine the reference temperature T under half-field heliostat conditions. A ; Obtain the reference temperature T A The heat output power P of the heat absorber below out,B and the corresponding normal direct irradiance DNI B ; According to the reference temperature T A The heat output power P of the heat absorber below out,B The corresponding normal direct irradiance DNIB, the receiver output heat power Pout,A under the half-field heliostat condition, and the corresponding normal direct irradiance DNI. A Calculate the reference temperature T A The thermal efficiency η of the heat absorber below B ; If the reference temperature T A If the temperature is lower than the molten salt outlet design temperature, a molten salt outlet temperature correction is performed to obtain the absorber thermal efficiency at the design temperature.

2. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 1, characterized in that, The thermal power test was performed under the half-field heliostat operating condition to determine the reference temperature T under the half-field heliostat operating condition. A The steps include: The reference temperature T is the highest outlet temperature that the receiver can actually achieve when operating at a preset minimum safe flow rate. A .

3. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 1, characterized in that, The heat output power of the heat absorber is calculated using the following formula: P out = ×c p ×(T out T in ) in, cp is the molten salt mass flow rate, cp is the average specific heat capacity of the molten salt, and T is the molten salt mass flow rate. in T represents the inlet temperature of the receiver. out This is the outlet temperature of the absorber.

4. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 1, characterized in that, Heat receiver thermal efficiency under operating condition B η B for: In the formula, k =0.5 and P loss,B - P loss,A =0, if the DNI is inconsistent between the half-field heliostat operating condition and the full-field heliostat operating condition. k for: 。 5. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 1, characterized in that, The process of correcting the molten salt outlet temperature includes: If the design temperature can be reached under the full-field heliostat operating conditions, a thermal power test at the design temperature will be performed to obtain the receiver output thermal power at the design temperature. The thermal efficiency of the receiver at the design temperature is calculated according to the following formula. : The output power of the receiver under operating condition B, Thermal efficiency of the receiver under operating condition B.

6. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 5, characterized in that, If the design temperature cannot be reached under the full-field heliostat operating conditions, then multiple thermal power tests at different outlet temperatures are performed to establish the correspondence between the molten salt outlet temperature and the receiver thermal power ratio, and the receiver thermal efficiency at the design temperature is extrapolated. The receiver thermal power ratio is: ,in The heat output power of the absorber at the i-th outlet temperature.

7. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 6, characterized in that, The relationship between the molten salt outlet temperature and the absorber heat power ratio is fitted as a first-order polynomial or a second-order polynomial.

8. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 1, characterized in that, The molten salt flow rate in the half-field heliostat operation is not lower than the minimum safe flow rate of the receiver, and the molten salt outlet temperature in the full-field heliostat operation is adjusted to the reference temperature T. A .

9. The method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations according to claim 1, characterized in that, When performing multiple thermal power tests at different outlet temperatures under the full-field heliostat operating conditions, the molten salt outlet temperature is controlled by adjusting the molten salt flow rate, which is not lower than the minimum safe flow rate and not higher than the design maximum flow rate.

10. The application of the method for testing the thermal efficiency of a receiver under non-ideal operating conditions and correcting temperature deviations as described in any one of claims 1-9, characterized in that, Used for receiver thermal efficiency testing and temperature deviation correction under non-ideal operating conditions.

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