Energy Efficiency Evaluation System for Renewable Energy Building Application Projects

1Energy Efficiency Evaluation System for Renewable Energy Building Application ProjectsOverview

According to the requirements of "Green Building Energy Efficiency Testing" and "GBT 50801-2013 Renewable Energy Building Application Engineering Evaluation Standards", energy efficiency evaluation must be conducted on building application projects that install solar water heating systems and solar photovoltaic systems. Only after passing the acceptance and energy efficiency testing can they be officially delivered for use and apply for energy-saving financial subsidies.

In response to the requirements of various relevant building inspection units, our company has developed a renewable energy solar hot water system and solar photovoltaic system energy efficiency evaluation testing instrument evaluation system that meets the requirements of China's building inspection departments, based on domestic and foreign energy efficiency evaluation standards. This energy efficiency evaluation system meets the testing requirements of large-scale solar water heating systems and solar photovoltaic systems on site. It adopts intelligent control technology, with high detection accuracy and work efficiency. When connected to computer testing software, it can generate energy efficiency evaluation reports for solar water heating systems, ensuring the design indicators and construction quality acceptance standards of solar water heating projects. It is the * testing tool for building quality inspection departments, manufacturers, and research units of Taiyuan University.

2、 Product testing based on standards

1. Performance Evaluation Specification for Solar Hot Water Systems GB/T 20095-2006;

2. GBT 50801-2013 Evaluation Standards for Renewable Energy Building Application Engineering

3. GB/T50364-2005 Technical Specification for Application of Solar Hot Water Systems in Civil Buildings

4. GB/T50604-2005 Evaluation Standard for Solar Hot Water Systems in Civil Buildings

5. GB/T18713-2002 Technical Specification for Design, Installation and Engineering Acceptance of Solar Hot Water Systems

6. Design drawings and design scheme documents;

7. Project application form;

8. Relevant equipment technical data and other documents

3、 Product Technical Features

1. By using an ultrasonic flowmeter, both static and dynamic testing methods can be employed, without the need to shut down the hot water system in use. This not only meets the detection requirements of actual working conditions, but also solves the problem of wiring difficulties caused by long-distance testing between the on-site heat collection end and the customer's water end. Convenient and convenient, reducing the labor intensity of on-site testing personnel.

2. It can accurately measure the heat output of the auxiliary heat source;

3. Adopting intelligent control technology, high detection accuracy and high work efficiency

4. Configure an outdoor rainproof and sun proof portable tester host. During testing, hang the tester host on the testing site or place it on the ground, install relevant outdoor sensors on the tester host, and measure directly on site. Convenient and convenient, improving work efficiency.

5. Configure 2 AC/DC power meters with non-destructive testing and high safety factor. The current uses AC/DC universal current clamps, which can measure the battery side and inverter side without damaging the cable;

6. Special software and hardware design ensures that the heat generation of the collection system starts from zero every day for several consecutive days, without the need for testing personnel to go to the site every day to record the efficiency of the collection system and then manually calculate it;

7. The analysis software can use wireless GPRS communication method, which is not limited by distance. It can collect real-time actual data from one or multiple testing sites remotely or in the office, and can monitor and diagnose the testing equipment at the testing site. Solved the problem of testers regularly going to the site to input data and check the operation status of equipment, making it convenient and reducing the labor intensity of on-site testers.

8. FSP10 Total Radiation Sensor: It has the accuracy and stability of Kipp&Zonen CMP21 second-class standard total radiation meter. The data obtained through outdoor selection of sunny, cloudy, and short-term cloudy and * measurements are very close to the data of CMP21, and the performance difference between the two is very small

4、 Evaluation projects (solar thermal utilization system and solar photovoltaic power system)

1. Heat generated by the collection system

2. Total energy consumption of the system

3. Heat loss coefficient of hot water storage tank

4. Efficiency of the heat collection system

5. Solar energy guarantee rate

6. Conventional energy substitution quantity (ton of standard coal)

7. Project cost-effectiveness ratio

8. Carbon dioxide emission reduction

9. Reduction of sulfur dioxide emissions

10. Dust emission reduction

11. Water supply temperature

12. Testing the photoelectric conversion efficiency of photovoltaic power systems in solar building applications

13. COP coefficient of heat pump (optional)

5Energy Efficiency Evaluation System for Renewable Energy Building Application Projectstest conditions

（1） Solar photovoltaic power system

1. Weather requirements for testing: The average temperature of the environment is 8 ℃ ≤ t ≤ 39 ℃, and the average flow velocity of the ambient air is not more than 4m/s. When the solar cell array is placed directly south, the start and end time of the test is from 1 hour before local solar noon to 1 hour after solar noon, for a total of 2 hours. During the testing period, the solar irradiance should not be less than 700w/m2.

2 System requirements: The photovoltaic power supply system for solar building applications should be installed and debugged according to the original design requirements, and run normally for at least 3 days before conducting photoelectric conversion efficiency testing. For an independent solar power generation system, the power meter is connected to the input end of the battery; For grid connected solar energy systems, the power meter should be connected to the output terminal of the inverter.

（2） Solar thermal utilization system

1. The key equipment used in the application of solar thermal systems in solar buildings, such as solar collectors and solar water heaters, should have corresponding full performance qualified testing reports and meet the requirements of relevant product standards;

2. The system should be installed and debugged according to the original design requirements, and run normally for at least 3 days before testing can be carried out;

3. All demonstration projects must reserve testing positions and conditions for relevant instruments according to the testing requirements, and their water consumption, water temperature, and other parameters must be tested under the design requirements;

During the testing period of the solar hot water system, the average ambient temperature is 8 ℃ ≤ ta ≤ 39 ℃;

5. The average flow rate of ambient air shall not exceed 4m/s;

At least 4 days of test results should have a distribution of solar irradiance in the following four segments: J1<8MJ/㎡· day; 8MJ/㎡· day ≤ J2 ＜ 12MJ/㎡· day; 12MJ/㎡· day ≤ J3 ＜ 16MJ/㎡· day; 16MJ/㎡ · day ≤ J4.

6、 Testing equipment, instruments, and their indicator parameters

7、 Testing method

（1） Solar photovoltaic power system

Before the experiment begins, all external auxiliary power sources should be cut off, and the solar radiation meter, electric power meter/temperature recorder, and anemometer should be installed and debugged, and the area of the solar cell array should be measured;

At the beginning of the experiment, the total radiation meter reading of solar radiation and the data of each instrument should be recorded simultaneously;

After the start of the experiment, the data of each instrument should be recorded every ten minutes;

4. Calculate the solar radiation amount H per unit area of solar panels during the experiment. For solar cell arrays located on different lighting planes, the solar radiation amount per unit area of solar panels on different lighting planes during the experiment should be calculated separately.

3. Data analysis

Calculate the power generation Q (MJ/(㎡)) per unit area of solar panels during system testing using equation (1):

T - Test time, unit: h;

W - reading of the electric power meter during the experiment, unit: kW;

Ac - solar panel area, unit: ㎡

Application of solar energy in buildings, photovoltaic power system, photovoltaic conversion efficiencyCalculate using equation (2):

When the solar panels are not on the same lighting surface, equation (3) can be used to calculate the photovoltaic power conversion efficiency of the solar building application photovoltaic power system：

T - Test time, unit: h;

W - reading of the electric power meter during the experiment, unit: kW;

Aci - Area of solar panels in different directions, unit: ㎡

Hi - Solar irradiance per unit area of solar panels with different orientations, unit: MJ/(㎡)

4. Engineering evaluation and solar thermal utilization system

（2） Solar thermal utilization system

1. Heat generated by the heat collection system

(1) Heat generated by a solar energy collection system: The useful energy provided by the solar collectors in a solar energy collection system, measured in MJ per day throughout the day.

(2) Testing time: The testing starts and ends when the required amount of solar radiation is reached.

(3) Required testing parameters: inlet temperature of the heat collection system, outlet temperature of the heat collection system, flow rate of the heat collection system, ambient temperature, ambient air flow rate, testing time.

(4) Data organization: When using a heat meter to test the above parameters, the heat output of the solar collection systemIt can be directly measured with a heat meter. When the above parameters are measured separately, the sampling time interval for the inlet and outlet temperature and flow rate of the collector shall not be less than 1 minute, and the recording time interval shall not be greater than 10 minutes. Heat generated by solar energy collection systemCalculated based on recorded temperature, flow rate, and other data.

2. Conventional heat source energy consumption of the system

(1) Energy consumption of conventional heat sources in the system: The energy consumption of conventional heat sources by auxiliary heat sources in the system (actual operating conditions: the heat that the system should provide to the user minus the heat from the heat collection system).

(2) Testing time: The testing starts and ends when the required amount of solar radiation is reached.

(3) Required testing parameters: auxiliary heat source heating capacity, ambient temperature, ambient air flow rate, testing time.

(4) Data analysis: When using electricity as an auxiliary heat source, measure the power consumption of the auxiliary heat source during the testing time.

When using other heat sources as auxiliary energy sources, the measurement method for the energy consumption of conventional heat sources in the system can be calculated using the following formula and method:

(1) Conventional heat source energy consumption of the system= QT-QC

in the formula

Q fz - energy consumption of conventional heat sources in the system, MJ；

Q T - The total energy that the system should provide to the user, MJ；

Q C - heat generated by the heat collection system, MJ。

(2) The total heat Q T that the system should provide to the user consists of the following three parts:

① The actual daily heat consumption of hot water provided by the system to users, Q G

② When the actual water supply does not meet the requirement of 60 ℃, additional heat Q A needs to be added

③ To meet the design requirements, the system should also provide heat Q S

So, the system should provide the total amount of heat to the user

3. Heat loss coefficient of hot water storage tank

(1) Thermal loss coefficient of hot water storage tank: a parameter indicating the insulation performance of the hot water storage tank, unit: W/K.

(2) Test time: Select one day, and the test starts and ends at 8 pm. At the beginning, the temperature of the hot water storage tank should not be lower than 40 ℃ and the temperature difference between the tank and the environment should not be less than 20 ℃. The test ends at 6 am the next day, for a total of 10 hours;

(3) Required test parameters: water temperature in the hot water storage tank at the beginning, water temperature in the hot water storage tank at the end, water capacity of the hot water storage tank, ambient temperature near the hot water storage tank, and test time.

(4) Data analysis

The heat loss coefficient of the hot water storage tank is calculated using equation (1):

Where:

--Heat loss coefficient of hot water storage tank, W/K;

--The density of water, kg/m3，

--The specific heat capacity of water, J/（kg·K）；

--The capacity of the hot water storage tank, m3;

--Cooling time, s；

--At the beginning, the water temperature in the hot water storage tank is ℃;

--At the end, the water temperature in the hot water storage tank is ℃;

--The average ambient temperature during the cooling period.

4. Efficiency of heat collection system

(1) Efficiency of the solar collection system: The ratio of the useful heat generated by the solar collection system during the testing period to the daily solar radiation energy projected onto the solar collector during the same testing period.

(2) Testing time: The testing starts and ends when the required amount of solar radiation is reached.

(3) Required testing parameters: solar collector daylighting area, solar irradiance, inlet temperature of the collection system, outlet temperature of the collection system, flow rate of the collection system, ambient temperature, ambient air flow rate, testing time.

(4) Data analysis

Calculate the efficiency of the heat collection system using equation (2):

Where:

——Efficiency of the heat collection system,%;

——The heat generated by the solar energy collection system, MJ;

——Solar collector daylighting area, ㎡;

——The solar irradiance on the daylighting surface of the solar collector, MJ/㎡;

5. Solar energy guarantee rate

(1) Solar energy guarantee rate: the ratio of the energy provided by the solar energy in the system to the total energy required by the system.

(2) Test time: The start and end time of the test reaches the required amount of solar radiation for the test;

(3) Required testing parameters: solar collector daylighting area, solar irradiance, inlet temperature of the collection system, outlet temperature of the collection system, flow rate of the collection system, ambient temperature, ambient air flow rate, heating capacity of the auxiliary heat source, and testing time.

(4) Data analysis

The solar energy guarantee rate of the system is calculated using equation (3):

Where:

F - System solar energy guarantee rate;

——The heat generated by the solar energy collection system, MJ;

——The total energy required by the system; MJ。

The total energy required by the systemCalculate using equation (4):

——Heating capacity of auxiliary heat source; MJ。

8、 Engineering evaluation

The basis for engineering evaluation is the project's "Application Report". The solar energy guarantee rate and the amount of conventional energy substitution are assessment indicators. If any of them fails to meet the requirements in the "Application Report", the project is judged as unqualified and cannot pass the evaluation.

• Solar energy guarantee rate

Method 1: Short term testing

The solar energy guarantee rate of the project shall be evaluated and shall not be lower than the solar energy guarantee rate proposed in the project's "Application Report".

The calculation of the annual solar energy guarantee rate is as follows:

1) The number of days with local daily solar radiation less than 8MJ/㎡ is x1 days; The number of days where the local daily solar radiation is less than 12MJ/㎡ and greater than or equal to 8MJ/㎡ is x2 days; The number of days where the local daily solar radiation is less than 16MJ/㎡ and greater than or equal to 12MJ/㎡ is x3 days; The number of days where the local daily solar radiation is greater than or equal to 16MJ/㎡ is x4 days;

2) After testing, the solar energy guarantee rate when the local daily solar radiation is less than 8MJ/㎡ isThe solar energy guarantee rate for local solar irradiance less than 12MJ/㎡ and greater than or equal to 8MJ/㎡ isThe solar energy guarantee rate for local solar irradiance less than 16MJ/㎡ and greater than or equal to 12MJ/㎡ isThe solar energy guarantee rate for local daily solar irradiance greater than or equal to 16MJ/㎡ is；

The annual solar energy guarantee rateFor:

Method 2: * Monitoring

The actual measured total solar radiation during a one-year cycle is J, which is the total energy required for a solar water heating system during a one-year cycleThe annual solar energy guarantee ratefor

2. Conventional energy substitution quantity (ton of standard coal)

The evaluation of the conventional energy substitution amount (ton of standard coal) for the project shall not be lower than the conventional energy substitution amount (ton of standard coal) proposed in the project's "Application Report".

Method 1: Short term testing

The calculation of the annual substitution of conventional energy is as follows:

After testing, the heat gain of the local solar radiation less than 8MJ/㎡ is Q1; the heat gain of the local solar radiation less than 8MJ/㎡ and greater than or equal to 12MJ/㎡ is Q2; the heat gain of the local solar radiation less than 16MJ/㎡ and greater than or equal to 12MJ/㎡ is Q3; the heat gain of the local solar radiation greater than or equal to 16MJ/㎡ is Q4;

Annual substitution of conventional energy(ton of standard coal) is

Method 2: * Monitoring

The actual measured total heat gain of the solar energy collection system within one year is QJ for the whole year; Annual substitution of conventional energy(Ton of standard coal) is:

Table 4-1 Evaluation Content of XX Demonstration Projects

9、 Standard configuration