Method for testing output power of resistor heating organic heat carrier boiler by using water as working medium

Abstract

The invention relates to a method for testing the output power of a resistance heating organic heat carrier boiler by using water as a working medium, in particular to a method for measuring the power of the organic heat carrier boiler, which can be used for conveniently measuring the thermal power of the resistance heating organic heat carrier boiler and has the characteristics of simplicity in measurement, relatively low test uncertainty and the like. According to the technical scheme, temperature and pressure measuring devices are installed on inlet and outlet pipelines of the resistance heating organic heat carrier boiler and used for testing the temperature and pressure of a working medium; 2) installing a flowmeter on a water inlet pipeline or a water outlet pipeline of the resistance heating organic heat carrier boiler; (3) water is injected into the resistance heating organic heat carrier boiler, a water source is connected, and it is guaranteed that enough cold water enters the boiler during boiler operation; 4) after starting to operate the boiler and keeping the operation stable, recording the volume flow VFW of water, the inlet water temperature tFW, En, the inlet water pressure PFW, En, the outlet water temperature tFW, Lv and the outlet water pressure PFW, Lv; and 5) calculating the output power Q of the resistance heating organic heat carrier boiler.

Description

Technical Field

[0001] The invention relates to a method for measuring the power of an organic heat carrier boiler, in particular to a method for testing the output power of a resistance-heated organic heat carrier boiler using water as a working medium. Background Art

[0002] At present, the "Special Equipment Catalogue" stipulates that organic heat carrier boilers with a rated power greater than or equal to 0.1MW are special equipment. The rated power of the boiler is a major parameter of the boiler.

[0003] At present, the rated power of organic heat carrier boilers adopts GB / T10180-2017 "Industrial Boiler Thermal Performance Test Procedure". GB / T10180-2017 stipulates that the thermal power of the boiler is obtained by measuring the inlet and outlet flow of the boiler and the specific heat and temperature of the inlet and outlet working fluids. According to the provisions of GB / T10180, to obtain the thermal power of the boiler under the test conditions, it is necessary to measure the mass flow rate (or volume flow rate and corresponding density) of the boiler working fluid, the temperature of the inlet and outlet of the boiler, the specific heat of the working fluid at that temperature and other data. For organic heat carrier boilers, since the working fluid organic heat carrier is a mixture, its thermophysical properties are different; in addition, there is a lack of corresponding standard methods for high-temperature density measurement and organic heat carrier specific heat capacity measurement. It is difficult to carry out the thermal power measurement of organic heat carrier boilers according to the current standards, which has restricted the evaluation of the thermal power indicators of organic heat carrier boilers. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the above-mentioned background technology and provide a method for testing the output power of a resistance-heated organic heat carrier boiler using water as a working medium. The method can conveniently measure the thermal power of a resistance-heated organic heat carrier boiler and has the characteristics of simple measurement and relatively small test uncertainty.

[0005] The technical solution provided by the present invention is:

[0006] A method for testing the output power of a resistance-heated organic heat carrier boiler using water as a working medium comprises the following steps in sequence:

[0007] 1) Install temperature and pressure measuring devices on the inlet and outlet pipes of the resistance-heated organic heat carrier boiler to test the temperature and pressure of the working fluid;

[0008] 2) Install a flow meter on the water inlet or outlet pipe of the resistance-heated organic heat carrier boiler;

[0009] 3) Inject water into the resistance-heated organic heat carrier boiler and connect it to a water source to ensure that sufficient cold water enters the boiler when the boiler is running;

[0010] 4) After the boiler starts running and keeps running stably, record the water flow rate (volume flow rate) V FW, inlet water temperature t FW,En , inlet water pressure P FW,En , outlet water temperature t FW,Lv , outlet water pressure P FW,Lv ;

[0011] 5) Calculate the output power Q of the resistance-heated organic heat carrier boiler according to the following formula:

[0012] Q=M FW ×(H Lv -H En ) / 3600 / 1000×A

[0013] Where: A is the heat dissipation loss correction coefficient, which corrects the inconsistent heat dissipation caused by working fluid substitution;

[0014] A is generally taken as 0.99, and the output power Q is in MW;

[0015] Density of influent water ρ En , enthalpy of water H En , using the measured inlet water temperature t FW,En , water inlet pressure P FW,En , and then consult the water and water vapor property table or related formula to get it;

[0016] Density of outlet water ρ Lv , Enthalpy of water H Lv , using the measured water outlet temperature t FW,En , water outlet pressure P FW,En , and then consult the table of properties of water and water vapor or related formulas to obtain it.

[0017] The resistance-heated organic heat carrier boiler is a newly produced resistance-heated organic heat carrier boiler that has not been injected with organic heat carrier, or a resistance-heated organic heat carrier boiler that has been completely exhausted of the internal organic heat carrier.

[0018] The water flow meter is installed in the inlet pipe or in the outlet pipe;

[0019] If the water flow meter is installed in the inlet pipe, the water mass flow rate M FW =V FW ×ρ En ;

[0020] If a water flow meter is installed in the outlet pipe, the water mass flow rate M FW =V FW ×ρ Lv .

[0021] The calculation units in the formula are as follows:

[0022] The volume flow rate of water is in m 3 / h, the density of water is kg / m 3 , the unit of enthalpy of water is kJ / kg.

[0023] The beneficial effects of the present invention are as follows: the provided method for testing the output power of a resistance-heated organic heat carrier boiler using water as the working fluid can conveniently measure the thermal power of the boiler, has the characteristics of accurate measurement data, simple measurement, and relatively small test uncertainty, and can effectively provide a thermal power test for a resistance-heated boiler when the thermophysical properties of the working fluid are unknown. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of measurement points in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings; however, the present invention is not limited to the following embodiments.

[0026] The method provided by the present invention uses water as a working medium to test the output power of a resistance-heated organic heat carrier boiler, comprising measuring the flow rate, temperature and pressure of water, and calculating the output power of the organic heat carrier boiler.

[0027] The calculation of the output power of the organic heat carrier boiler refers to running the organic heat carrier in place of water, measuring the flow rate, temperature and pressure of the water, and calculating the output power of the organic heat carrier boiler.

[0028] The data to be measured include: working fluid flow rate per unit time (in kg / h or m 3 / h), water inlet temperature (in °C), water inlet pressure (in MPa), water outlet temperature (in °C), water outlet pressure (in MPa); look up the table or use the formula to determine the water density (in kg / m 3 ), the enthalpy of water (in kJ / kg).

[0029] There is no need to measure the flow rate, density, specific heat capacity, pressure, temperature, power input power and other parameters of the boiler's organic heat carrier.

[0030] Example 1

[0031] Figure 1 The model shown is a newly produced LDR0.35 electric heating organic heat carrier boiler produced by a boiler manufacturing unit. The boiler design rated power is 0.35MW. The density and specific heat of the organic heat carrier in the boiler operation state are unknown, and the boiler thermal power is required to be tested.

[0032] Since the density and specific heat data of organic heat carrier are unknown, the thermal power of organic heat carrier boiler cannot be tested according to the current GB / T10180. Therefore, according to the present invention, water is injected into the new boiler, a flow meter is installed (installed on the water inlet pipe or the water outlet pipe, and in this embodiment, it is installed on the water inlet pipe), connected to the water source, and then the boiler is operated. Then measure Figure 1 The water flow rate, inlet water temperature and pressure, outlet water temperature and pressure are shown, and the thermal power output of the organic heat carrier boiler is calculated.

[0033] 1. At the boiler water inlet pipe, measure the water inlet flow rate V FW =15m 3 / h; inlet water temperature t FW,En =20.0℃, water inlet pressure P FW,En =0.3MPa.

[0034] 2. Measure the outlet water temperature t at the boiler outlet pipe. FW,Lv =40.0℃, water outlet pressure P FW,Lv =0.2MPa.

[0035] 3. The calculation process is as follows:

[0036] By the inlet water temperature t FW,En =20.0℃, water inlet pressure P FW,En =0.3MPa, check the water-steam property table or use the IAPWS-IF97 formula to get: the enthalpy of water inlet H En =84.29 kJ / kg, the density of the incoming water ρ En =998.34kg / m 3 ; Water mass flow rate M FW =V FW ×ρ En =15×998.34=14975.1kg / h;

[0037] The outlet water temperature t FW,Lv =40.0℃, water outlet pressure P FW,Lv =0.2MPa, check the water-steam property table or use the IAPWS-IF97 formula to get the enthalpy of water H Lv =167.80kJ / k;

[0038] Therefore: The output power of the resistance-heated organic heat carrier boiler is:

[0039] Q=M FW ×(H Lv -H En ) / 3600 / 1000×A=14975.1×(167.80-84.29) / 3600 / 1000

[0040] ×0.99=0.3439MW.

[0041] Among them: A is 0.99.

[0042] The working principle of the present invention is: the output power of the resistance-heated organic heat carrier boiler is determined by the resistance heating element and the power supply. Under the same conditions of the resistance heating element and the power supply, the effective boiler output heat power can be measured by using water with stable physical properties. Generally, the output temperature of the organic heat carrier boiler is high, and the heat dissipation loss of the boiler is greater than when measured with water; for conventional insulation, the heat dissipation loss of the electric heating hot water boiler is generally 1%, and the heat dissipation loss of the electric heating organic heat carrier boiler is generally 2%, so the heat dissipation correction coefficient A is taken as 0.99.

Claims

1. A method for testing the output power of a resistance-heated organic heat carrier boiler using water as a working medium, comprising the following steps in sequence: 1) Install temperature and pressure measuring devices on the inlet and outlet pipes of the resistance-heated organic heat carrier boiler to test the working fluid temperature and pressure; 2) Install a flow meter on the water inlet or outlet pipe of the resistance-heated organic heat carrier boiler; 3) Inject water into the resistance-heated organic heat carrier boiler and connect it to a water source to ensure that sufficient cold water enters the boiler when the boiler is running; 4) After the boiler starts running and keeps running stably, record the water volume flow rate V FW , inlet water temperature t FW,En , inlet water pressure P FW,En , outlet water temperature t FW,Lv , outlet water pressure P FW,Lv ; 5) Calculate the output power Q of the resistance-heated organic heat carrier boiler according to the following formula: Q=M FW ×(H Lv -H En ) / 3600 / 1000×A Where: A is the heat dissipation loss correction coefficient, which corrects the inconsistent heat dissipation caused by working fluid substitution; A is generally taken as 0.99, and the output power Q is in MW; Density of influent water ρ En , enthalpy of water H En , using the measured inlet water temperature t FW,En , water inlet pressure P FW,En , and then consult the water and water vapor property table or related formula to get it; Density of outlet water ρ Lv , Enthalpy of water H Lv , using the measured water outlet temperature t FW,En , water outlet pressure P FW,En , and then consult the table of properties of water and water vapor or related formulas to obtain it.

2. The method for testing the output power of a resistance-heated organic heat carrier boiler using water as a working medium according to claim 1, characterized in that: The resistance-heated organic heat carrier boiler is a newly produced resistance-heated organic heat carrier boiler that has not been injected with organic heat carrier, or a resistance-heated organic heat carrier boiler that has been completely exhausted of the internal organic heat carrier.

3. The method for testing the output power of a resistance-heated organic heat carrier boiler using water as a working medium according to claim 2, characterized in that: The water flow meter is installed in the inlet pipe or in the outlet pipe; If the water flow meter is installed in the inlet pipe, the water mass flow rate M FW =V FW ×ρ En ; If a water flow meter is installed in the outlet pipe, the water mass flow rate M FW =V FW ×ρ Lv .

4. The method for testing the output power of a resistance-heated organic heat carrier boiler using water as a working medium according to claim 3 is characterized in that: The calculation units in the formula are as follows: The volume flow rate of water is in m 3 / h, the density of water is kg / m 3 , the unit of enthalpy of water is kJ / kg.

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