CN115342867B - Compressed air flow measuring and calculating method based on heat-humidity balance - Google Patents
Compressed air flow measuring and calculating method based on heat-humidity balance Download PDFInfo
- Publication number
- CN115342867B CN115342867B CN202210881482.0A CN202210881482A CN115342867B CN 115342867 B CN115342867 B CN 115342867B CN 202210881482 A CN202210881482 A CN 202210881482A CN 115342867 B CN115342867 B CN 115342867B
- Authority
- CN
- China
- Prior art keywords
- compressed air
- outlet
- cooler
- heat
- inlet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims description 25
- 239000003570 air Substances 0.000 claims abstract description 208
- 238000004364 calculation method Methods 0.000 claims abstract description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 21
- 239000012080 ambient air Substances 0.000 claims abstract description 14
- 238000000691 measurement method Methods 0.000 claims abstract description 11
- 229920006395 saturated elastomer Polymers 0.000 claims abstract description 6
- 239000002826 coolant Substances 0.000 claims description 39
- 238000005259 measurement Methods 0.000 claims description 20
- 230000000704 physical effect Effects 0.000 claims description 9
- 238000004458 analytical method Methods 0.000 claims description 7
- 238000004891 communication Methods 0.000 claims description 5
- 238000009834 vaporization Methods 0.000 claims description 3
- 230000008016 vaporization Effects 0.000 claims description 3
- 238000004146 energy storage Methods 0.000 description 5
- 230000007613 environmental effect Effects 0.000 description 5
- 238000011282 treatment Methods 0.000 description 5
- 239000012530 fluid Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000007791 dehumidification Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/20—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
- G01F1/32—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
Abstract
A compressed air flow measurement method based on heat-humidity balance, comprising: step S1: calculating the water vapor partial pressure of the compressed air inlet and outlet; step S2: calculating the saturated moisture content of the compressed air inlet and outlet; step S3: calculating the moisture content of the ambient air; step S4: comparing the air moisture content; step S5: judging the actual moisture content of a compressed air inlet and a compressed air outlet of the cooler; step S6: performing enthalpy calculation of an inlet and an outlet of compressed air; step S7: calculating the heat exchange amount; step S8: a compressed air flow calculation is performed. The measuring precision is high and the applicability is good.
Description
Technical Field
The invention relates to the technical field of fluid measurement, in particular to a compressed air flow measuring and calculating method based on heat-humidity balance.
Background
The pressurized air with reduced volume and increased pressure by the work of the air compressor is called compressed air. Compressed air is an important power source and is widely used in various industries such as automobiles, chemical engineering, energy utilization and the like. The energy consumption of the compressed air system accounts for 15% -30% of the total power consumption of enterprises according to statistics, and is an important component of the traditional industrial energy.
Under the background of carbon neutralization age, the energy storage technology can realize peak clipping, valley filling and smooth output, reduces the influence of the fluctuation and intermittence of renewable energy sources on the electric energy quality of a power grid, and has important strategic significance for future energy conversion in China. The compressed air energy storage (Compressed Air Energy Storage, CAES for short) technology has the characteristics of large scale, strong flexibility and the like, and is considered to have great development potential and application prospect.
In the preparation, treatment and storage and transportation processes of compressed air, the flow metering of the compressed air is closely related to the energy consumption, the dehumidification effect, the cost settlement and other aspects of system operation, and the accurate measurement is very critical. However, at present, the use of compressed air has the following general problems: the flow of the compressed air is difficult to measure or the measurement precision is not high, or the measured value cannot be checked, the leakage of the compressed air lacks an effective supervision method, and the use of the compressed air is in a state without consciousness of cost and restriction. This problem occurs directly in connection with compressed air flow measurement methods and apparatus.
In the current industry of compressed air flow measurement, the orifice plate flowmeter can influence the measurement precision due to accumulated water in front of the orifice plate and the measurement precision due to easy accumulated water of a pressure guiding pipe of the differential pressure flowmeter due to the existence of water-carrying condition of compressed air, so that the vortex street flowmeter is dominant. The vortex shedding flowmeter is a meter in which a non-streamline type vortex generator is arranged in fluid, and the fluid alternately separates and releases two strings of vortex which are regularly staggered on two sides of the generator. When the flow cross section is fixed, the flow velocity is proportional to the volumetric flow. Therefore, the flow can be measured by measuring the oscillation frequency. The vortex street type flowmeter has the advantages of no movable parts, wide measuring range and small pressure loss. Vortex shedding meters also have many limitations in engineering practice, which also results in vortex shedding meters that measure compressed air flow with less than expected accuracy, including:
1. the external vibration can cause the vortex shedding flowmeter to generate measurement errors and even not work normally. The high flow velocity impact of the channel fluid can cause the cantilever of the vortex street generator to generate additional vibration, so that the measurement accuracy is reduced, and the influence of the large pipe diameter is more obvious. If the compressed air flow is to be measured in the vicinity of the air compressor, the vibration generated will have a great influence on the measurement result.
2. The straight pipe section has high requirements. The vortex shedding flowmeter generally requires to ensure straight pipe sections of 5-20D (different manufacturers require different) after the front 10-40D, so as to ensure that compressed air uniformly passes through the vortex shedding flowmeter, and if an upstream pipeline of the flowmeter is provided with an elbow or an expansion or contraction pipe, the requirement on the length of the straight pipe sections is higher. In engineering practice, there are often cases where the space is limited and the requirement of the straight pipe section cannot be met, so that the measurement accuracy is also greatly affected.
It can be seen that in engineering practice, the problems of inaccurate measurement may exist in the conventional vortex street, orifice plate and differential pressure type flowmeter. If the compressed air flow measuring and calculating method and the device with high precision and strong applicability can be provided, the monitoring and the control of the industrial production and the compressed air energy storage process can be enhanced, the improvement of the energy efficiency of the system is facilitated, and the requirements of carbon neutralization time background are met.
Disclosure of Invention
In view of the above, the present invention provides a compressed air flow measurement method based on heat-humidity balance, which has high measurement accuracy and better applicability, so as to solve the above problems.
A compressed air flow measurement method based on heat-humidity balance, comprising:
step S1: calculating the water vapor partial pressure of the compressed air inlet and outlet;
step S2: calculating the saturated moisture content of the compressed air inlet and outlet;
step S3: calculating the moisture content of the ambient air;
step S4: comparing the air moisture content;
step S5: judging the actual moisture content of a compressed air inlet and a compressed air outlet of the cooler;
step S6: performing enthalpy calculation of an inlet and an outlet of compressed air;
step S7: calculating the heat exchange amount;
step S8: a compressed air flow calculation is performed.
Further, in the step S1, the calculation of the water vapor partial pressure of the compressed air inlet and outlet is based on the calculation of the hyland-wexler equation:
wherein p is q,b The water vapor partial pressure of the air inlet and outlet of the cooler is compressed; p is the inlet and outlet pressure of compressed air of the cooler; calculated cooler compressed air inlet and outletThe wet contents are respectively denoted as d 1q And d 2q 。
Further, in the step S3, the ambient air moisture content calculation queries the air moisture content d available in the enthalpy-humidity map according to the instant ambient temperature and the relative humidity 0 。
Further, in the step S4, the moisture content d of the compressed air inlet and outlet of the cooler is compared respectively 1 、d 2 Moisture content d with air 0 。
Further, in the step S5, when d 1q ≤d 0 When d 1 ＝d 1q The method comprises the steps of carrying out a first treatment on the surface of the When d 1q ＞d 0 When d 1 ＝d 0 The method comprises the steps of carrying out a first treatment on the surface of the When d 2q ≤d 0 When d 2 ＝d 2q The method comprises the steps of carrying out a first treatment on the surface of the When d 2q ＞d 0 When d 2 ＝d 0 。
Further, in the step S6, the method for calculating the enthalpy value of the compressed air inlet and outlet includes:
h＝c a T+d(λ+c s T)
wherein c a The specific heat is fixed for the compressed air, and is selected according to an air physical property table; t is the temperature of a compressed air inlet and outlet of the cooler; d is the actual moisture content of the compressed air inlet and outlet of the cooler; lambda is the vaporization latent heat of the steam and is selected from a steam physical property table according to the pressure; c s The specific heat of the water vapor is determined, and the specific heat is selected from a water vapor physical property table according to the pressure; the enthalpy values of the inlet and outlet of the compressed air of the cooler are respectively h calculated by a formula 1 And h 2 。
Further, in the step S7, the heat exchange amount calculation formula is:
Q L ＝c L m L (T L2 -T L1 )；
wherein Q is L Heat exchange for the cooler; c L Constant pressure specific heat for the cooling medium; m is m L Is the flow of the cooling medium; t (T) L2 、T L1 The cooling medium outlet and inlet temperatures, respectively.
Further, in the step S8, the compressed air flow is calculated by energy balance:
Q L ＝60ρ N V N (h 2 -h 1 )；
wherein ρ is N Is the standard density of air at 0 ℃; v (V) N Is the standard volumetric flow of compressed air at 0 ℃.
The invention also provides a compressed air flow measuring and calculating device based on heat-humidity balance, which comprises the following components: the system comprises an air compressor, a compressed air cooler connected with the output end of the air compressor, a compressed air inlet thermometer arranged at the front end of the compressed air cooler, a compressed air inlet pressure gauge, a compressed air outlet thermometer arranged at the rear end of the compressed air cooler, an ambient temperature and humidity meter for measuring ambient air, a cooling medium inlet thermometer arranged at the medium input end of the compressed air cooler, a cooling medium flow meter arranged at the medium output end of the compressed air cooler, a data acquisition module connected with the compressed air inlet thermometer, the compressed air inlet pressure gauge, the compressed air outlet pressure gauge, the ambient temperature and humidity meter, the cooling medium inlet thermometer, the cooling medium flow meter and the cooling medium outlet thermometer, a calculation analysis module communicated with the data acquisition module, and a local display unit and a data communication unit communicated with the calculation analysis module.
Compared with the prior art, the compressed air flow measuring and calculating method based on heat and humidity balance comprises the following steps:
step S1: calculating the water vapor partial pressure of the compressed air inlet and outlet;
step S2: calculating the saturated moisture content of the compressed air inlet and outlet;
step S3: calculating the moisture content of the ambient air;
step S4: comparing the air moisture content;
step S5: judging the actual moisture content of a compressed air inlet and a compressed air outlet of the cooler;
step S6: performing enthalpy calculation of an inlet and an outlet of compressed air;
step S7: calculating the heat exchange amount;
step S8: a compressed air flow calculation is performed. The measuring precision is high and the applicability is good.
Drawings
Embodiments of the invention are described below with reference to the accompanying drawings, in which:
FIG. 1 is a block diagram of a compressed air flow measurement device based on heat and humidity balance according to the present invention.
Fig. 2 is a flow chart of a compressed air flow measurement method based on heat-humidity balance.
Detailed Description
Specific embodiments of the present invention will be described in further detail below based on the drawings. It should be understood that the description herein of the embodiments of the invention is not intended to limit the scope of the invention.
Referring to fig. 1, the compressed air flow measuring and calculating device based on heat and humidity balance provided by the invention comprises an air compressor 100, a compressed air cooler 6 connected with the output end of the air compressor 100, a compressed air inlet thermometer 7 and a compressed air inlet thermometer 8 arranged at the front end of the compressed air cooler 6, a compressed air outlet thermometer 4 and a compressed air outlet thermometer 5 arranged at the rear end of the compressed air cooler 6, an ambient temperature and humidity meter 9 for measuring ambient air, a cooling medium inlet thermometer 10 and a cooling medium flowmeter 11 arranged at the medium input end of the compressed air cooler 6, a cooling medium outlet thermometer 12 arranged at the medium output end of the compressed air cooler 6, a data acquisition module 1 connected with the compressed air inlet thermometer 7, the compressed air inlet thermometer 8, the compressed air outlet thermometer 4, the compressed air outlet thermometer 5, the ambient temperature and humidity meter 9, the cooling medium inlet thermometer 10, the cooling medium flowmeter 11 and the cooling medium outlet thermometer 12, a calculation and analysis module 2 in communication with the data acquisition module 1, and a local display unit 31 in communication with the calculation and analysis module 2.
The cooling medium is water, so that the measurement of the cooling medium flow meter 11 is more accurate.
The compressed air outlet pressure gauge 4 is used for measuring the compressed air outlet pressure and transmitting the compressed air outlet pressure to the data acquisition module 1.
The compressed air outlet thermometer 5 is used for measuring the temperature of the compressed air outlet and transmitting the temperature to the data acquisition module 1.
The compressed air cooler 6 can utilize the original cooler or the newly-arranged cooler in the compressed air system to cool and exchange heat with the compressed air. In order to reduce the volume flow and facilitate the dehumidification of the compressed air, the compressed air is generally provided after the pressure is increased.
The compressed air inlet thermometer 7 is used for measuring the inlet temperature of the cold measurement medium and transmitting the cold measurement medium to the data acquisition module 1.
The compressed air inlet pressure gauge 8 is used for measuring the compressed air inlet pressure and transmitting the compressed air inlet pressure to the data acquisition module 1.
The environmental hygrothermograph 9 is used for measuring the environmental temperature and the environmental relative humidity and transmitting the environmental temperature and the environmental relative humidity to the data acquisition module 1.
The cooling medium inlet thermometer 10 is used for measuring the cooling medium inlet temperature and transmitting the cooling medium inlet temperature to the data acquisition module 1.
The cooling medium flowmeter 11 is used for measuring the flow of the cooling medium and transmitting the flow to the data acquisition module 1. The cooling medium flow meter 11 is preferably a vortex shedding flow meter.
The cooling medium outlet thermometer 12 is used for measuring the cooling medium outlet temperature and transmitting the cooling medium outlet temperature to the data acquisition module 1.
The driving end C of the air compressor 100 is connected with a power supply, and the ambient hygrothermograph 9 is arranged at an ambient air inlet end A1 of the air compressor 100.
The rear end of the air cooler 6 serves as a compressed air outlet end A2.
The medium input B1 of the compressed air cooler 6 is used for supplying the cooling medium, the medium output B2 is used for discharging the cooling medium, and the cooling medium can be recycled through the circulation unit.
Referring to fig. 2, the compressed air flow measurement method based on heat-humidity balance provided by the invention comprises the following steps:
step S1: calculating the water vapor partial pressure of the compressed air inlet and outlet;
the temperature of the compressed air is generally in the range of 0-200 ℃, and the water vapor partial pressure p of the air inlet and outlet of the cooler is generally equal to the temperature of the compressed air q,b Can be calculated based on the hyland-wexler equation:
wherein c 1 ～c 6 C is a fixed coefficient 1 ＝-5800.2206；c 2 ＝1.3914993；c 3 ＝-0.04860239；c 4 ＝0.41764768×10 -4 ；c 5 ＝-0.14452093×10 -7 ；c 6 ＝6.5459673。
Step S2: calculating the saturated moisture content of the compressed air inlet and outlet;
the moisture content of the compressed air inlet and outlet of the cooler can be calculated according to a moisture content formula:
wherein,
p q,b the water vapor partial pressure of the compressed air inlet and outlet of the cooler is unit kPa;
p is the inlet and outlet pressure of the compressed air of the cooler, and the unit is kPa.
The calculated moisture content of the compressed air inlet and outlet of the cooler is respectively recorded as d 1q And d 2q In kg/kg.
Step S3: calculating the moisture content of the ambient air;
the compressed air is obtained by mechanically pressurizing the ambient air, and the moisture content of the compressed air inlet and the compressed air outlet is not higher than the moisture content of the ambient air, so that the moisture content of the ambient air needs to be calculated and checked. Query based on instant ambient temperature and relative humidityMoisture content d of air obtainable from enthalpy-humidity diagram 0 。
Step S4: comparing the moisture content of air, i.e. comparing the moisture content d of compressed air in and out of the cooler 1 、d 2 Moisture content d with air 0 ；
Step S5: judging the actual moisture content of a compressed air inlet and a compressed air outlet of the cooler;
the actual moisture content of the compressed air inlet and outlet of the cooler is d 1 And d 2 Unit kg/kg, then:
when d 1q ≤d 0 When d 1 ＝d 1q ；
When d 1q ＞d 0 When d 1 ＝d 0 ；
When d 2q ≤d 0 When d 2 ＝d 2q ；
When d 2q ＞d 0 When d 2 ＝d 0 。
Step S6: performing enthalpy calculation of an inlet and an outlet of compressed air;
the method for calculating the enthalpy value of the inlet and outlet of the compressed air of the cooler comprises the following steps:
h＝c a T+d(λ+c s T)
wherein c a The specific heat is fixed for the compressed air, and the unit kJ/(kg.K) can be selected according to an air physical property table;
t is the temperature of a compressed air inlet and outlet of the cooler and is a unit K;
d is the actual moisture content of a compressed air inlet and a compressed air outlet of the cooler, and the unit is kg/kg;
lambda is the vaporization latent heat of the water vapor, the unit kJ/kg can be selected from a water vapor physical property table according to the pressure;
c s the specific heat per unit kJ/(kg.K) is determined by the steam physical property table according to the pressure.
The enthalpy values of the inlet and outlet of the compressed air of the cooler can be calculated according to the formula to be h 1 And h 2 Unit kJ/kg.
Step S7: calculating the heat exchange amount;
the heat exchange amount of the cooler is calculated as follows:
Q L ＝c L m L (T L2 -T L1 )
wherein Q is L The heat exchange amount of the cooler is kW;
c L constant pressure specific heat of the cooling medium, unit kJ/(kg.K);
m L the unit kg/s is the flow rate of the cooling medium;
T L2 、T L1 the cooling medium outlet and inlet temperatures, in K, respectively.
Step S8: a compressed air flow calculation is performed.
The compressed air flow can be obtained through energy balance measurement, and the specific method comprises the following steps:
Q L ＝60ρ N V N (h 2 -h 1 )
wherein,
ρ N is the standard density of air at 0 ℃, unit kg/Nm 3 ；
V N For a standard volumetric flow of compressed air at 0 ℃, unit Nm 3 And/min. The mass flow or the volume flow can be calculated as required.
The data of the calculated compressed air flow rate may be displayed locally by the local display unit 31 or remotely by the data communication unit 32.
Compared with the prior art, the method and the device for indirectly measuring and calculating the compressed air flow by utilizing the heat-humidity balance have the advantages that the requirements of water accumulation, vibration and straight pipe sections can be overcome, the measurement and calculation of the compressed air flow is realized, the method and the device have good engineering applicability, an effective supervision method is provided for the compressed air industrial application, the compressed air energy storage and other systems, and the method and the device are beneficial to improving the gas consumption awareness; secondly, accurate measurement and calculation of the compressed air flow is also beneficial to diagnosis and analysis of the running condition of the compressed air system; and thirdly, the compressed air flow is indirectly calculated by utilizing the heat-humidity balance, and a data checking method is provided for vortex street and other types of flow meters, so that the preparation, treatment and storage and transportation processes of the compressed air are operated in a better state, and the energy efficiency of a system is improved and the carbon emission index is reduced. The invention also provides a compressed air flow measuring and calculating device based on heat-humidity balance.
The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions or improvements within the spirit of the present invention are intended to be covered by the claims of the present invention.
Claims (7)
1. A compressed air flow measuring and calculating method based on heat-humidity balance is characterized by comprising the following steps of: the compressed air flow measuring and calculating device based on heat-humidity balance is used for measuring and calculating, and the compressed air flow measuring and calculating device based on heat-humidity balance comprises: the system comprises an air compressor, a compressed air cooler connected with the output end of the air compressor, a compressed air inlet thermometer and a compressed air inlet pressure gauge which are arranged at the front end of the compressed air cooler, a compressed air outlet thermometer and a compressed air outlet thermometer which are arranged at the rear end of the compressed air cooler, an ambient temperature and humidity meter for measuring ambient air, a cooling medium inlet thermometer and a cooling medium flowmeter which are arranged at the medium input end of the compressed air cooler, a cooling medium outlet thermometer arranged at the medium output end of the compressed air cooler, a data acquisition module connected with the compressed air inlet thermometer, the compressed air outlet thermometer, the ambient temperature and humidity meter, the cooling medium inlet thermometer and the cooling medium flowmeter, a calculation analysis module communicated with the data acquisition module, and a local display unit and a data communication unit communicated with the calculation analysis module; compressed air flow measuring and calculating method based on heat-humidity balance
Comprising the following steps:
step S1: calculating the water vapor partial pressure of the compressed air inlet and outlet;
step S2: calculating the saturated moisture content of the compressed air inlet and outlet;
step S3: calculating the moisture content of the ambient air;
step S4: comparing the air moisture content;
step S5: judging the actual moisture content of a compressed air inlet and a compressed air outlet of the cooler;
step S6: performing enthalpy calculation of an inlet and an outlet of compressed air;
step S7: calculating the heat exchange amount;
step S8: performing compressed air flow calculation;
in the step S1, the calculation of the water vapor partial pressure of the compressed air inlet and outlet is based on the calculation of the hyland-wexler equation:
wherein T is the temperature of a compressed air inlet and outlet of the cooler; c 1 ～c 6 C is a fixed coefficient 1 ＝-5800.2206；c 2 ＝1.3914993；c 3 ＝-0.04860239；c 4 ＝0.41764768×10 -4 ；c 5 ＝-0.14452093×10 -7 ；c 6 ＝6.5459673；
In the step S8, the compressed air flow is obtained through energy balance measurement:
Q L ＝60ρ N V N (h 2 -h 1 )；
wherein h is 1 Compressing an air inlet enthalpy value for a chiller; h is a 2 Compressing an air outlet enthalpy value for the chiller; ρ N Is the standard density of air at 0 ℃; v (V) N Is the standard volumetric flow of compressed air at 0 ℃.
2. The heat and humidity balance based compressed air flow measurement method of claim 1, wherein: in the step S2, the compressed air inlet and outlet saturated moisture content calculation is performed according to a moisture content formula:
wherein p is q,b The water vapor partial pressure of the air inlet and outlet of the cooler is compressed; p is the inlet and outlet pressure of compressed air of the cooler; the calculated moisture content of the compressed air inlet and outlet of the cooler is respectively recorded as d 1q And d 2q 。
3. The heat and humidity balance based compressed air flow measurement method of claim 2, wherein: in the step S3, the ambient air moisture content calculation queries the air moisture content d available in the psychrometric chart according to the instant ambient temperature and the relative humidity 0 。
4. A method for measuring and calculating compressed air flow based on heat and humidity balance according to claim 3, wherein: in the step S4, the moisture content d of the compressed air inlet and outlet of the cooler is respectively compared 1 、d 2 Moisture content d with air 0 。
5. The heat and humidity balance based compressed air flow measurement method of claim 4, wherein: in the step S5 of the above-mentioned process,
when d 1q ≤d 0 When d 1 ＝d 1q ；
When d 1q ＞d 0 When d 1 ＝d 0 ；
When d 2q ≤d 0 When d 2 ＝d 2q ；
When d 2q ＞d 0 When d 2 ＝d 0 。
6. The heat and humidity balance based compressed air flow measurement method of claim 1, wherein: in the step S6, the method for calculating the enthalpy value of the compressed air inlet and outlet includes:
h＝c a T+d(λ+c s T)；
wherein c a The specific heat is fixed for the compressed air, and is selected according to an air physical property table; t is the temperature of a compressed air inlet and outlet of the cooler; d is the actual moisture content of the compressed air inlet and outlet of the cooler; lambda is the vaporization latent heat of the steam and is selected from a steam physical property table according to the pressure; c s The specific heat of the water vapor is determined, and the specific heat is selected from a water vapor physical property table according to the pressure; the enthalpy values of the inlet and outlet of the compressed air of the cooler are respectively h calculated by a formula 1 And h 2 。
7. The heat and humidity balance based compressed air flow measurement method of claim 1, wherein: in the step S7, the heat exchange amount calculation formula is:
Q L ＝c L m L (T L2 -T L1 )；
wherein Q is L Heat exchange for the cooler; c L Constant pressure specific heat for the cooling medium; m is m L Is the flow of the cooling medium; t (T) L2 、T L1 The cooling medium outlet and inlet temperatures, respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210881482.0A CN115342867B (en) | 2022-07-26 | 2022-07-26 | Compressed air flow measuring and calculating method based on heat-humidity balance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210881482.0A CN115342867B (en) | 2022-07-26 | 2022-07-26 | Compressed air flow measuring and calculating method based on heat-humidity balance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115342867A CN115342867A (en) | 2022-11-15 |
| CN115342867B true CN115342867B (en) | 2023-11-17 |
Family
ID=83949542
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210881482.0A Active CN115342867B (en) | 2022-07-26 | 2022-07-26 | Compressed air flow measuring and calculating method based on heat-humidity balance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115342867B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701216A (en) * | 2002-09-19 | 2005-11-23 | 萨塞克斯大学 | Detection and measurement of two-phase flow |
| JP2008020113A (en) * | 2006-07-12 | 2008-01-31 | Hitachi Industrial Equipment Systems Co Ltd | Compressed air supply device |
| CN104034377A (en) * | 2014-06-17 | 2014-09-10 | 西安交通大学 | Air compressor flow measurement device and calibration system and method thereof |
| CN104776884A (en) * | 2015-04-17 | 2015-07-15 | 中国科学院工程热物理研究所 | Method for obtaining outlet state parameters of plate-fin type aftercooler |
| CN110245323A (en) * | 2019-05-15 | 2019-09-17 | 上海电科电机科技有限公司 | The calculation method of air compressor system operational efficiency |
| JP6835373B1 (en) * | 2020-03-27 | 2021-02-24 | 株式会社フクハラ | Drain amount measurement system generated in compressed pneumatic circuit |
| CN112660409A (en) * | 2020-12-17 | 2021-04-16 | 威海广泰空港设备股份有限公司 | Enthalpy difference control method of airplane ground air conditioning system |
| CN114091276A (en) * | 2021-11-25 | 2022-02-25 | 安徽省特种设备检测院 | On-line calculation method for boiler thermal efficiency of household garbage incineration boiler |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6917886B2 (en) * | 2000-11-06 | 2005-07-12 | Adam Cohen | Microflow based differential pressure sensor |
| US8583384B2 (en) * | 2009-10-05 | 2013-11-12 | Robert J. Mowris | Method for calculating target temperature split, target superheat, target enthalpy, and energy efficiency ratio improvements for air conditioners and heat pumps in cooling mode |
-
2022
- 2022-07-26 CN CN202210881482.0A patent/CN115342867B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1701216A (en) * | 2002-09-19 | 2005-11-23 | 萨塞克斯大学 | Detection and measurement of two-phase flow |
| JP2008020113A (en) * | 2006-07-12 | 2008-01-31 | Hitachi Industrial Equipment Systems Co Ltd | Compressed air supply device |
| CN104034377A (en) * | 2014-06-17 | 2014-09-10 | 西安交通大学 | Air compressor flow measurement device and calibration system and method thereof |
| CN104776884A (en) * | 2015-04-17 | 2015-07-15 | 中国科学院工程热物理研究所 | Method for obtaining outlet state parameters of plate-fin type aftercooler |
| CN110245323A (en) * | 2019-05-15 | 2019-09-17 | 上海电科电机科技有限公司 | The calculation method of air compressor system operational efficiency |
| JP6835373B1 (en) * | 2020-03-27 | 2021-02-24 | 株式会社フクハラ | Drain amount measurement system generated in compressed pneumatic circuit |
| CN112660409A (en) * | 2020-12-17 | 2021-04-16 | 威海广泰空港设备股份有限公司 | Enthalpy difference control method of airplane ground air conditioning system |
| CN114091276A (en) * | 2021-11-25 | 2022-02-25 | 安徽省特种设备检测院 | On-line calculation method for boiler thermal efficiency of household garbage incineration boiler |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115342867A (en) | 2022-11-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20160138951A1 (en) | Method and measuring apparatus for determining specific quantities for gas quality | |
| CN202092924U (en) | Measuring device of water content of gas | |
| CN107014240B (en) | A kind of cooling tower cooling efficiency monitoring method and system | |
| CN104407008A (en) | Test system for evaluating local condensing heat transfer performance of mixed steam | |
| CN102338568A (en) | Online monitoring system and method for performance of condenser in power plant based on cleanness coefficient index | |
| CN2784902Y (en) | Meter for on-line monitoring air leakage of steam turbine vacuum system | |
| CN106123243A (en) | Air-conditioning device refrigeration capacity test method based on multidimensional curve fitting algorithm | |
| CN106595755A (en) | Large-scale petrochemical device air cooler energy efficiency evaluation on-line monitoring system and method | |
| CN102353403B (en) | Methods for measuring chilled water flow and cooling medium flow of central air-conditioning host machine | |
| CN104615857A (en) | Method for determining heat loads of condenser of condensing steam turbine | |
| CN115342867B (en) | Compressed air flow measuring and calculating method based on heat-humidity balance | |
| CN103267539B (en) | Method for measuring upper terminal difference and lower terminal difference of horizontal-type three-section feed water heater | |
| CN206710109U (en) | A kind of Properties of Air-conditioning Unit online detection instrument | |
| CN111933974A (en) | Method for testing dew point temperature of humidifying reaction gas of fuel cell | |
| CN203981332U (en) | A kind of automotive air-conditioning system pressure test device | |
| CN115064737B (en) | Method for monitoring hydrogen use accumulation amount of fuel cell | |
| CN202693298U (en) | Performance detection test stand of airplane environment control accessory | |
| CN111929065B (en) | Method for measuring thermal economy of driving steam turbine | |
| CN110926643A (en) | Condensate supercooling degree on-line monitoring device and method for condensing steam turbine unit | |
| CN110332911A (en) | Using the measurement method of steam condenser vacuum measurement heat exchanging pipe fouling thickness | |
| CN112547294B (en) | Method for acquiring inlet air volume of medium-speed coal mill under thermal state | |
| CN114061691A (en) | Method and system for measuring gas consumption of aerospace gas supply system | |
| CN101832545B (en) | Method for measuring temperatures of out-flowing water and discharged water of heater of turbine steam cooler | |
| CN210741871U (en) | Cooler simulation test platform | |
| CN108680260B (en) | System for measuring and analyzing performance of compressed air energy storage system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |