CN-121981472-A - Crude oil heating energy optimization method based on photovoltaic network electric combination

CN121981472ACN 121981472 ACN121981472 ACN 121981472ACN-121981472-A

Abstract

The invention relates to an energy consumption optimization method based on photovoltaic network combined crude oil heating, which is realized by a crude oil heating system based on the photovoltaic network combined, and comprises an energy supply subsystem and an energy consumption subsystem, wherein the energy supply subsystem consists of a photovoltaic power generation unit, an energy storage unit and a power grid energy supplementing unit, the energy consumption subsystem consists of a heat pump load unit and an energy consumption unit of a crude oil storage tank, the heat pump operation parameters in the energy consumption subsystem are optimized firstly, the photovoltaic-energy storage-power grid cooperative proportion of the energy supply subsystem is optimized, the efficient low-consumption operation of crude oil heating is realized through two-stage progressive optimization, and a mathematical model between the heating effect of a storage tank and the heat pump operation parameters is constructed when the heat pump operation parameters are optimized, so that the heat pump operation parameter combination with the optimal heating effect is obtained. According to the invention, by using the two-stage progressive logic with optimized energy subsystem parameters and optimized energy subsystem proportion, the high-efficiency and low-consumption operation of crude oil heating is realized.

Inventors

SUN WEI
LIU YUDUO
WANG WENCHAO
Zhang Chengliu
SHAO QI
WANG ZHIHUA

Assignees

东北石油大学

Dates

Publication Date: 20260505
Application Date: 20260125

Claims (9)

1. The crude oil heating energy optimizing method based on the photovoltaic network is characterized by being realized by a crude oil heating system based on the photovoltaic network, and comprises an energy supply subsystem and an energy utilization subsystem, wherein the energy supply subsystem consists of a photovoltaic power generation unit, an energy storage unit and a power grid energy supplementing unit; the energy utilization subsystem consists of a heat pump load unit and an energy utilization unit of a crude oil storage tank, wherein the heat pump operation parameters in the energy utilization subsystem are optimized firstly, then the photovoltaic-energy storage-power grid cooperative proportioning of the energy utilization subsystem is optimized, and the high-efficiency low-consumption operation of crude oil heating is realized through two-stage progressive optimization; When the heat pump operation parameters are optimized, a mathematical model between the heating effect of the storage tank and the heat pump operation parameters is constructed, and a heat pump operation parameter combination with the optimal heating effect is obtained; ; Wherein g' is a calculated value of the temperature rising rate of the crude oil in the storage tank, omega 0、 ω 1 、ω 2 、 ω 3 、ω 4、 ω 5 is a regression coefficient of the built model, T out is the hot water temperature of the water outlet end of the heat pump, and V out is the hot water flow of the water outlet end of the heat pump.
2. The photovoltaic-network-based combined crude oil heating energy optimization method as claimed in claim 1, which is characterized by comprising the following steps: The method comprises the steps of collecting key operation data of an energy utilization subsystem, arranging temperature sensing probes at different heights of a crude oil storage tank guide post, collecting crude oil temperatures at different liquid levels in real time, taking an average value measured by all probes as the integral temperature of crude oil in a storage tank, respectively arranging a temperature sensor and a turbine flowmeter at a water outlet end and a water return end of a heat pump, acquiring the water outlet temperature, the water return temperature and the instantaneous flow of a water supply and return pipeline in real time, simultaneously, accessing a power meter at an input end of the heat pump, and monitoring the effective power of the heat pump in real time; Forming an operation parameter orthogonal experiment table according to the hot water temperature and the hot water flow of the crude oil storage tank, taking the heating rate of the crude oil as a storage tank heating effect evaluation index, constructing a mathematical model between the storage tank heating effect and the heat pump operation parameter by adopting a multi-element nonlinear regression mathematical method, and iteratively solving the model by an interior point method to obtain a heat pump operation parameter combination with the optimal heating effect, thereby completing primary optimization of an energy utilization subsystem; measuring and calculating the real-time effective power of a full link from photovoltaic power generation to a heat pump terminal, arranging a metering device at the equipment end of an energy supply subsystem according to energy supply logic of photovoltaic main supply, energy storage and energy supplement and power grid bottom covering, installing power meters at the total input end of a power main distribution cabinet, the input end of an energy storage converter, the output end of a grid-connected cabinet and the input end of a heat pump host, and counting the change of the effective power of the full link and each link; According to the established dynamic energy balance equation, photovoltaic priority direct energy, energy storage discharge adjustment energy, electric network bottom covering energy compensation = heat pump real-time energy consumption + energy storage charge energy consumption, solving optimal proportioning relation of photovoltaic direct supply, energy storage discharge capacity and electric network electric compensation capacity in different time periods, and finally forming an actual photovoltaic-energy storage-electric network collaborative energy supply proportioning scheme, so as to realize secondary optimization of an energy supply subsystem of the crude oil heating system; optimal proportioning relation between photovoltaic direct supply capacity, energy storage discharge capacity and electric network electricity supplementing capacity in different time periods: ; In the formula, Representing the optimal photovoltaic direct supply at the ith moment; representing the optimal energy storage and discharge quantity at the ith moment; And (5) representing the optimal power grid electricity supplementing quantity at the ith moment.
3. The method for optimizing crude oil heating energy based on photovoltaic network combined combination according to claim 2, wherein the mathematical model between the heating effect of the storage tank and the operation parameters of the heat pump is calculated to obtain the optimal flow of the heat pump Temperature of water outlet end Combining synchronous recording of instantaneous temperature of reflux cold water after heat exchange by crude oil storage tank coil And the instantaneous flow rate of the return cold water in the end pipeline And then calculating to obtain the heat pump heating quantity Q heat : ; On the basis, calculating the heat pump energy efficiency ratio COP, and judging whether the heat pump COP is in a high-efficiency interval or not, wherein the COP is more than or equal to 3.5: ; wherein COP represents the heat pump energy efficiency ratio, P heat represents the heat pump effective power per unit time, C w represents the specific heat capacity of water, Ρ w represents the density of the water, And j represents a heat loss coefficient of 0.2.
4. The photovoltaic-network-based combined crude oil heating energy optimization method according to claim 3 is characterized by comprising the following steps: (1) The optimization objective function N tot (i) and constraint conditions are constructed as follows: ; N tot (i) represents the running cost of the crude oil heating system at the moment i, N grid (i) represents the electricity price at the moment i of the area, delta i represents the continuous running time of the heat pump, delta i=1h, and p grid (i) represents the power supply power of the power grid at the moment i; (2) Establishing dynamic energy balance constraint conditions: adopting photovoltaic priority direct supply, energy storage regulation and power grid bottom logic, constructing an energy balance equation in a time-sharing manner, and covering a scene of all days: daytime, photovoltaic surplus: Charging and storing residual electricity; daytime, the photovoltaic is insufficient: Energy storage and power grid energy supplement; at night, no photovoltaic: The energy storage is discharged preferentially, and the energy is supplemented by the power grid after the power is deficient; (3) Establishing SOC equation constraint conditions: ; wherein M bat represents the energy storage rated capacity, SOC (i) represents the energy storage charge state at the moment i, the energy storage initial charge state SOC (0) is 0.5, and SOC (i-1) represents the energy storage charge state at the moment i-1; (4) Upper and lower limit constraints for each power variable: photovoltaic output constraint: ; Energy storage SOC constraints: ; Energy storage power constraint: , , Energy storage power constraint: , , and (3) supplementing electricity constraint for a power grid: ; Wherein P stc represents the upper limit of the output power of the photovoltaic unit, P ch,max represents the maximum charging power of the stored energy, P dis,maxt represents the maximum discharging power of the stored energy, P grid,max represents the upper limit of the distribution capacity of the station, P ch (i) represents the charging power of the energy storage device at the moment i, P dis (i) represents the discharging power of the energy storage device at the moment i, and P stc (i) represents the upper limit of the output power of the photovoltaic unit at the moment i; Converting the nonlinear constraint problem in the objective function into a quadratic programming sub-problem to solve by adopting sequence quadratic programming, and finally outputting the optimal time intervals on the basis of given initialization iteration points and parameters P pv (i) 0 、P ch (i) 0 、P dis (i) 0 、P grid (i) 0 、soc(i) 0 、、、 Cost of required operation Obtaining the optimal proportioning relation between the photovoltaic direct supply quantity, the energy storage discharge quantity and the power grid electricity supplementing quantity in different time periods.
5. The method for optimizing heating energy of crude oil based on electric coupling of photovoltaic networks according to claim 4, wherein the photovoltaic power generation unit comprises a photovoltaic array, a photovoltaic inverter and an alternating current combiner box, the photovoltaic array receives solar energy to generate direct current, the direct current is converted into alternating current with the same frequency and the same voltage as a power grid through the photovoltaic inverter, the output end of the photovoltaic inverter is divided into two paths, one path is connected to a power main distribution cabinet through the alternating current combiner box, power is supplied to the heat pump load unit directly preferentially, and the other path is connected to an energy storage converter of the energy storage unit for charging surplus electric energy into energy storage facilities.
6. The method for optimizing heating energy consumption of crude oil based on electric coupling of photovoltaic networks according to claim 5, wherein the energy storage unit comprises an energy storage facility and an energy storage converter, the energy storage facility is used for storing surplus photovoltaic electric energy, the input end of the energy storage facility is connected with the output end of the power main distribution cabinet through the energy storage converter and receives photovoltaic charging, meanwhile, when the photovoltaic output is insufficient, the output end converts direct current into alternating current through the energy storage converter and then is connected into the power main distribution cabinet, the energy storage facility discharges and supplements energy to the heat pump load unit, and the energy storage converter is simultaneously responsible for voltage and current adjustment in the charging and discharging processes, so that the overcharge and overdischarge of the energy storage facility are avoided.
7. The method for optimizing crude oil heating energy based on photovoltaic network electric combination of claim 6, wherein the power grid of the power grid energy supplementing unit is connected into the power main power distribution cabinet through the grid-connected cabinet and used as a bottom-covered energy supplementing device, and when the sum of photovoltaic direct supply and energy storage and discharge still cannot meet the heat pump energy consumption, the power grid energy supplementing unit supplements electric energy to the power main power distribution cabinet through the grid-connected cabinet.
8. The method for optimizing crude oil heating energy based on photovoltaic network electric combination is characterized in that an input end of the heat pump load unit is connected with an output end of a power main distribution cabinet, electric energy from photovoltaic, energy storage or power grid is received and distributed, a transformer is arranged between the main distribution cabinet and the heat pump load and is responsible for stably distributing mixed electric energy of direct supply, energy storage discharge and power grid energy supplementing of the collected photovoltaic to the heat pump unit, the heat pump unit converts the electric energy into heat energy, and a stable heat source is provided for the energy utilization unit of the storage tank through a hot water circulation pipeline.
9. The method for optimizing crude oil heating energy based on the photovoltaic network combined combination of claim 8, wherein the input end of the crude oil storage tank energy utilization unit is connected with the hot water output end of the heat pump load unit, the heat energy transferred by the heat pump is received through the heat exchange coil in the storage tank, the crude oil is heated, the cold water after heat exchange is returned to the heat pump unit through the water return pipeline, the heat energy circulation is completed, and the temperature requirement in the crude oil storage or transportation process is ensured.

Description

Crude oil heating energy optimization method based on photovoltaic network electric combination Technical Field The invention relates to the technical field of oil and gas storage and transportation, in particular to a crude oil heating system based on photovoltaic network electric combination and an energy consumption optimization method. Background With the increasing demand for crude oil reserves, large floating roof tanks have become the preferred oil storage facilities for petroleum reserve bases due to their technical and economic advantages. The tank storage of waxy crude oil is easy to gel in a low-temperature environment, so that safety accidents such as a chuck and the like are caused, and domestic related oilfield enterprises need to heat the crude oil storage tank to ensure safe and stable operation of the storage tank. The heat energy consumption for crude oil storage per year accounts for more than 80% of the total energy consumption, if only traditional heating facilities such as a heating furnace and the like are used as main energy sources for the heating process of the storage tank, the energy consumption of the heating equipment is overhigh, the carbon emission is increased, and the environment-friendly development requirement is contrary, so that clean energy substitution has become a necessary trend in the industry. The solar energy is used as a high-quality clean energy source, the photoelectric technology can efficiently convert light energy into electric energy, and the electric energy is preferentially supplied to a heat pump, so that high-temperature heat energy is provided for industrial production such as crude oil heating, and the clean substitution of the traditional energy source is realized. The current oil field enterprises mainly use a photovoltaic power generation and grid power energy supply system, the system passively depends on photovoltaic natural output and grid fixed energy supplementing, photovoltaic energy supply fluctuation is difficult to adapt, and the grid dependence is high. In the past, a static proportioning method is mainly adopted for energy supply matching research of a crude oil heating system. According to the method, based on historical data or a theoretical formula, the average output of the photovoltaic and the total energy consumption of the system are estimated, the fixed energy supply proportion of the photovoltaic and the power grid is further determined, the proportion cannot follow the real-time change of solar radiation intensity and ambient temperature in operation, dynamic fluctuation of the energy consumption of the heat pump is adjusted in real time, and the proportion is manually reset only after serious problems occur. However, in the actual running process, solar radiation and ambient temperature are always in a real-time fluctuation state, so that the actual output force of the photovoltaic array is in nonlinear dynamic fluctuation, and the actual output force deviates from an average stable value estimated by historical data. The traditional static proportioning method can not timely regulate and control the dynamic change, when the photovoltaic output is higher than a preset estimated value, the redundant electric energy is difficult to be timely adapted and consumed by a system to cause renewable energy waste, and conversely, when the photovoltaic output is lower than the preset estimated value, the power grid energy supplementing is still supplied according to a fixed proportion, so that the real-time energy consumption requirement of a heat pump can not be met, the crude oil heating rate is directly reduced, the temperature of a storage tank is fluctuated, the crude oil gelation risk is caused, and if the power grid energy supplementing is temporarily added for compensating an energy supplying gap, the whole operation cost of the system is increased. Disclosure of Invention The invention aims to provide an energy optimizing method for crude oil heating based on photovoltaic network electric coupling, which is used for solving the problem that the crude oil heating system of the existing large storage tank cannot be scientifically and accurately optimized reasonably. The technical scheme includes that the crude oil heating energy optimizing method based on the photovoltaic network electric combination is realized by a crude oil heating system based on the photovoltaic network electric combination, the crude oil heating system based on the photovoltaic network electric combination comprises an energy supply subsystem and an energy utilization subsystem, the energy supply subsystem consists of a photovoltaic power generation unit, an energy storage unit and a power grid energy supplementing unit, the energy utilization subsystem consists of a heat pump load unit and an energy utilization unit of a crude oil storage tank, heat pump operation parameters in the energy utilization subsystem are optimized firstly, then the photovoltaic-e