阅读说明：本技术 一种低碳排放型油气田压缩机及其控制方法 (Low-carbon emission type oil-gas field compressor and control method thereof ) 是由 陈奕阳 刘浩宇 周昱霖 郭芊汝 秦晋 陈志军 于 2021-09-23 设计创作，主要内容包括：本发明公开一种低碳排放型油气田压缩机及其控制方法,用以解决现有技术中油气田用压缩机不仅造成排放污染,且余热能源无法有效利用的问题。包括：压缩机系统包括发动机和压缩机,发动机为压缩机供能,至少一套压缩机系统中发动机排出的高温烟气通过换热器将余热能量送入余热发电系统,余热发电系统包括有机朗肯循环ORC系统以及汽轮机发电系统,系统转换开关用于切换ORC系统和汽轮机发电系统；发动机、压缩机、换热器以及余热发电系统皆通过PLC控制系统进行控制。有益效果为减少油气田的碳排放,充分利用高温废气的能量,进行余热发电。(The invention discloses a low-carbon emission type oil-gas field compressor and a control method thereof, which are used for solving the problems that the compressor for the oil-gas field in the prior art causes emission pollution and waste heat energy sources cannot be effectively utilized. The method comprises the following steps: the compressor system comprises an engine and a compressor, the engine supplies energy to the compressor, high-temperature flue gas exhausted by the engine in at least one set of compressor system sends waste heat energy to the waste heat power generation system through the heat exchanger, the waste heat power generation system comprises an Organic Rankine Cycle (ORC) system and a steam turbine power generation system, and a system change-over switch is used for switching the ORC system and the steam turbine power generation system; the engine, the compressor, the heat exchanger and the waste heat power generation system are all controlled by the PLC control system. The waste heat power generation device has the advantages that carbon emission of an oil-gas field is reduced, and energy of high-temperature waste gas is fully utilized to carry out waste heat power generation.)

1. A low carbon emission type oil and gas field compressor is characterized by comprising: at least one set of compressor system, heat exchanger, waste heat power generation system and PLC control system; the compressor system comprises an engine and a compressor, the engine supplies energy to the compressor, high-temperature flue gas exhausted by the engine in at least one set of compressor system sends waste heat energy to the waste heat power generation system through the heat exchanger, the waste heat power generation system comprises a system change-over switch, an Organic Rankine Cycle (ORC) system and a steam turbine power generation system, and the system change-over switch is used for switching the ORC system and the steam turbine power generation system; the engine, the compressor, the heat exchanger and the waste heat power generation system are all controlled by the PLC control system.

2. The low carbon emission field compressor of claim 1 wherein the power output of the cogeneration system is coupled to the compressor for use.

3. The low carbon emission field compressor as defined in claim 1, wherein the engine comprises: one or more of a gas turbine, a four-stroke engine, and a two-stroke engine.

4. The low carbon emission field compressor as defined in claim 1, wherein the compressor comprises: one or more of a reciprocating compressor, a centrifugal compressor, and a screw compressor.

5. The low carbon emission field compressor of claim 1 wherein the engine and compressor are skid-mounted individually, the ORC system is skid-mounted individually, the turbine power generation system is skid-mounted individually, and the ORC system is unitized with standard container size.

6. A method of controlling a low carbon emission field compressor as claimed in claim 1, wherein the method comprises:

if the waste heat of the engine of the compressor is applied to the condition that the output power of the waste heat power generation system is larger than or equal to a first power setting threshold value, switching to a steam turbine power generation system; if the output power of the waste heat power generation system is smaller than a first power setting threshold value, switching to an ORC system; wherein the first power setting threshold is 1000 kW;

the PLC control system monitors the air inlet pressure value and the air outlet pressure value of the compressor and ensures that the air inlet pressure value and the air outlet pressure value are in a normal range;

meanwhile, the PLC control system monitors the output voltage, the output current and the frequency of a generator in the waste heat power generation system; and when the output voltage and the frequency are ensured to be the commercial power standard, the smoke gas inflow of the residual heat power generation system is increased so as to increase the power generation power.

7. The low carbon emission type oil and gas field compressor of claim 1, wherein the PLC control system monitors the intake pressure value and the exhaust pressure value of the compressor, and ensures that the intake pressure value and the exhaust pressure value are in a normal range, comprising:

if the air inlet pressure value is lower than a first low-pressure set threshold value or higher than a first high-pressure set threshold value, emergency shutdown is carried out through the safety interlocking protection system ESD; if the air inlet pressure is higher than the first low pressure set threshold and lower than the normal range, the opening degree of an air inlet valve of the compressor is increased to supplement the air inlet pressure; if the air inlet pressure is higher than the normal range and lower than the first high pressure setting threshold, the opening of an air inlet valve of the compressor is reduced, and the air inlet pressure is reduced;

if the exhaust pressure is lower than a second low-pressure set threshold or higher than a second high-pressure set threshold, emergency shutdown is carried out through ESD; if the exhaust pressure is higher than a second low pressure set threshold and lower than a normal range, increasing the rotation speed of the engine; if the exhaust pressure is above the normal range and below a second high pressure set threshold, the engine speed is reduced.

The technical field is as follows:

the invention relates to the technical field of oil and gas production of oil and gas fields, in particular to a low-carbon-emission oil and gas field compressor and a control method thereof.

Background art:

with the emission of carbon dioxide in various countries, greenhouse gases are increased dramatically, and threat life systems. Under the background, greenhouse gases are reduced in countries in the world in a global agreement mode, and the countries put forward targets of carbon peak reaching and carbon neutralization, namely that the countries promise that the emission of carbon dioxide is not increased before 2030, and for 2060, the emitted carbon dioxide is completely offset by adopting various modes of tree planting, energy conservation, emission reduction and the like.

When oil gas field exploitation and natural gas are carried, need carry out the pressure boost to natural gas or oil field associated gas, the prior art mainly adopts reciprocating type or centrifugal compressor to carry out the pressure boost, and the compressor drive is motor or gas engine, and corresponding power ratio is bigger, generally at 300KW-5000 KW. For an electric drive engine, the purchased consumed electric energy correspondingly and indirectly increases carbon emission; the gas engine burns fuels such as natural gas and the like, and directly increases carbon emission. For oil and gas field exploitation and natural gas transportation, due to factors such as environmental limitation, a gas engine is generally adopted as a power source of a compressor, the application quantity is large, huge pressure is caused on energy conservation and emission reduction of enterprises, and contradiction exists between the gas engine and the national development strategy direction.

The invention content is as follows:

the invention provides a low-carbon emission type oil-gas field compressor and a control method thereof, which are used for solving the problems that the compressor for the oil-gas field in the prior art causes emission pollution and waste heat energy sources cannot be effectively utilized.

The invention provides a low-carbon emission type oil-gas field compressor, which comprises: at least one set of compressor system, heat exchanger, waste heat power generation system and PLC control system; the compressor system comprises an engine and a compressor, the engine supplies energy to the compressor, high-temperature flue gas exhausted by the engine in at least one set of compressor system sends waste heat energy to the waste heat power generation system through the heat exchanger, the waste heat power generation system comprises an Organic Rankine Cycle (ORC) system and a steam turbine power generation system, and a system change-over switch is used for switching the ORC system and the steam turbine power generation system; the engine, the compressor, the heat exchanger and the waste heat power generation system are all controlled by the PLC control system.

Preferably, the power output part of the waste heat power generation system is connected to the compressor for use.

Preferably, the engine includes: one or more of a gas turbine, a four-stroke engine, and a two-stroke engine.

Preferably, the compressor includes: one or more of a reciprocating compressor, a centrifugal compressor, and a screw compressor.

Preferably, the engine and compressor are pryed separately, the ORC system is pryed separately, the turbine power generation system is pryed separately, and the ORC system is unitized with standard container sizes.

A control method of a low-carbon emission type oil and gas field compressor is characterized by comprising the following steps:

if the waste heat of the engine of the compressor is applied to the condition that the output power of the waste heat power generation system is larger than or equal to a first power setting threshold value, switching to a steam turbine power generation system; if the output power of the waste heat power generation system is smaller than a first power setting threshold value, switching to an ORC system; wherein the first power setting threshold is 1000 kW;

the PLC control system monitors the air inlet pressure value and the air outlet pressure value of the compressor and ensures that the air inlet pressure value and the air outlet pressure value are in a normal range;

meanwhile, the PLC control system monitors the output voltage, the output current and the frequency of a generator in the waste heat power generation system; and when the output voltage and the frequency are ensured to be the commercial power standard, the smoke gas inflow of the residual heat power generation system is increased so as to increase the power generation power.

Preferably, the PLC control system monitors the air intake pressure value and the air exhaust pressure value of the compressor, and ensures that the air intake pressure value and the air exhaust pressure value are in a normal range, and the method comprises the following steps:

if the air inlet pressure value is lower than a first low-pressure set threshold value or higher than a first high-pressure set threshold value, emergency shutdown is carried out through the safety interlocking protection system ESD; if the air inlet pressure is higher than the first low pressure set threshold and lower than the normal range, the opening degree of an air inlet valve of the compressor is increased to supplement the air inlet pressure; if the air inlet pressure is higher than the normal range and lower than the first high pressure setting threshold, the opening of an air inlet valve of the compressor is reduced, and the air inlet pressure is reduced;

if the exhaust pressure is lower than a second low-pressure set threshold or higher than a second high-pressure set threshold, emergency shutdown is carried out through ESD; if the exhaust pressure is higher than a second low pressure set threshold and lower than a normal range, increasing the rotation speed of the engine; if the exhaust pressure is above the normal range and below a second high pressure set threshold, the engine speed is reduced.

The beneficial effects include: the low-carbon emission type oil-gas field compressor in the embodiment of the invention can reduce carbon emission of the oil-gas field during exploitation, storage and transportation, fully utilizes energy contained in high-temperature waste gas generated by an engine of the natural gas compressor, further performs waste heat power generation, saves energy and is beneficial to environmental protection; meanwhile, the waste heat power generation system is integrally integrated into the compressor, on one hand, the waste heat power generation system is uniformly and centrally controlled by the PLC, the waste heat power generation system can be well matched with the compressor in operation, and on the other hand, the power utilization of the natural gas compressor for power generation of the waste heat power generation system and the output of partial power are adjusted.

Description of the drawings:

FIG. 1 is a schematic structural diagram of a low carbon emission type oil and gas field compressor in accordance with a preferred embodiment.

FIG. 2 is a schematic diagram of the ORC cycle of a preferred embodiment.

The specific implementation mode is as follows:

in order to provide a low-carbon emission type oil and gas field compressor and a control method thereof, which are used for solving the problems that the smoke energy emission of the compressor influences the environment and the heat waste is large in the prior art, the following description is made on the preferred embodiment of the invention by combining the attached drawings of the specification.

Referring to fig. 1 to 2, a low-carbon emission type oil and gas field compressor 3 according to an embodiment of the present invention includes: the system comprises at least one set of compressor 3 system, a heat exchanger 1, a waste heat power generation system and a PLC control system 4; the compressor 3 system comprises an engine 2 and a compressor 3, the engine 2 supplies energy to the compressor 3, high-temperature flue gas exhausted by the engine 2 in at least one set of compressor 3 system sends waste heat energy to the waste heat power generation system through the heat exchanger 1, the waste heat power generation system comprises a system change-over switch 5, an Organic Rankine Cycle (ORC) system 6 and a steam turbine power generation system 7, and the system change-over switch 5 is used for switching the ORC system 6 and the steam turbine power generation system 7; the engine 2, the compressor 3, the heat exchanger 1 and the waste heat power generation system are all controlled by a PLC control system 4.

Specifically, in the production of oil and gas fields, the power driving end of the compressor 3, i.e. the gas engine 2, uses the fuel such as natural gas, and a large amount of natural gas energy is discharged into the atmosphere in a thermal manner, the utilization rate of the fuel such as natural gas is greatly reduced due to the thermal discharge, the fuel such as natural gas consumed under unit power is synchronously increased, so that under the same power, the carbon emission is synchronously increased, the utilization rate of natural gas is relatively low, even though the engine 2 in the most advanced prior art has the highest efficiency of less than 40%, the rest is discharged in the manners of heat radiation and high-temperature flue gas, generally, the effective utilization energy accounts for 33% of the total energy, the mechanical friction loss is about 5%, the low-temperature heat radiation accounts for 27%, and the high-temperature flue gas accounts for 35%.

High temperature exhaust emissions are common for diesel, natural gas, or biomass powered engines 2. Almost all the energy contained in the waste gas generated in the fuel combustion process can be fully utilized by the low-carbon emission type compressor 3 in the invention to carry out waste heat power generation by fully utilizing the energy contained in the high-temperature waste gas generated by the engine 2 of the natural gas compressor 3, so that the energy is saved, the emission is reduced, the electric energy can be transmitted to the natural gas compressor 3 for use, and the redundant part is output to the outside.

The low-carbon emission type compressor 3 in the embodiment of the invention comprises at least one set of compressor 3 system, a heat exchanger 1, a waste heat power generation system and a PLC control system 4, wherein high-temperature flue gas of an engine 2 in the compressor 3 system is subjected to energy exchange output with an ORC system 6 or a steam turbine power generation system 7 through the heat exchanger 1; the PLC control system 4 integrally controls the operation parameters of the engine 2, the operation parameters of the compressor 3 and various operation parameters of the ORC or the gas turbine for operation and power generation. When a plurality of compressor 3 systems are installed on one oil and gas field site, a set of waste heat power generation system is also adopted for centralized utilization, the utilization efficiency is improved, and the investment cost is also reduced.

When the output power of the waste heat power generation system of the accounting compressor 3 is lower than 1000kW, the ORC system 6 is preferably adopted, and when the output power of the waste heat power generation system of the accounting compressor 3 is higher than 1000kW, the steam turbine power generation system 7 is preferably adopted for power generation.

The power output part of the waste heat power generation system is connected to the compressor 3 for use, and if surplus exists, electric energy is output to the outside.

The engine 2 includes: one or more of a gas turbine, a four-stroke engine 2, and a two-stroke engine 2. The compressor 3 includes: one or more of a reciprocating compressor 3, a centrifugal compressor 3, and a screw compressor 3.

Engine 2 and compressor 3 are the sled alone, and ORC system 6 is the sled alone, and steam turbine power generation system 7 is the sled alone, and ORC system 6 is the unit with standard container size, the road transport of being convenient for. The waste heat power generation system is connected with a high-temperature flue gas emission pipeline of the engine 2 through the heat exchanger 1. The compressor 3 system, the power generation system and the PLC are integrated into a whole.

When the ORC system 6 is used for generating power, high-temperature flue gas of the engine 2 exchanges heat with water in the heat exchanger 1 at about 450 ℃ to generate medium-low pressure water or steam at 100-200 ℃, and then carries out secondary heat exchange with an organic heat medium in the ORC system 6 through the medium-low pressure water or steam to generate steam with certain pressure and temperature, and the steam enters a turbine machine to do work to drive a generator to generate power; the medium and low pressure water or steam is cooled and then recycled. The organic heat medium in the ORC system 6 is low boiling point organic matter which has higher utilization efficiency for the heat source with the cross-bottom temperature.

When the steam turbine power generation system 7 is used for generating power, the high-temperature flue gas of the engine 2 directly heats softened water to form superheated steam, the superheated steam enters the steam turbine to expand and do work, so that the blades rotate to drive the generator to generate power, and the steam after the work is cooled and recycled.

The control method of the low carbon emission type oil and gas field compressor 3 according to the present invention will be described in detail.

The control method of the low-carbon emission type oil-gas field compressor 3 comprises the following steps:

if the output power of the waste heat power generation system is greater than or equal to the first power setting threshold value, switching to a steam turbine power generation system 7; if the output power of the waste heat power generation system is smaller than a first power setting threshold value, switching to an ORC system 6; wherein the first power setting threshold is 1000 kW;

the PLC control system 4 monitors the air inlet pressure value and the air outlet pressure value of the compressor 3, and ensures that the air inlet pressure value and the air outlet pressure value are in a normal range;

meanwhile, the PLC control system 4 monitors the output voltage, the output current and the frequency of a generator in the waste heat power generation system; and when the output voltage and the frequency are ensured to be the commercial power standard, the smoke gas inflow of the residual heat power generation system is increased so as to increase the power generation power.

Specifically, the waste heat power generation system is selected according to the waste heat accounting utilization power of the station compressor 3, the waste heat utilization power is calculated through the waste heat energy of the station compressor 3, when the waste heat utilization power is larger than 1000KW, the steam turbine power generation system 7 is preferably designed, and if the waste heat accounting utilization power is smaller than 1000KW according to the station compressor 3, the ORC system 6 is preferably designed. The choice of waste heat power generation system, whether the turbine is used for generating power or the ORC system 6, is 1000kW for the first power setting threshold, which is selected firstly based on the power of the compressor 3 itself used in a field station and the waste heat energy of the engine 2, and secondly based on the power generation efficiency of the turbine power generation system 7 and the ORC system 6 and under which waste heat energy the maximum effect can be exerted. The residual heat energy of the engine 2 calculates the total energy of the used natural gas according to the power of the engine 2, then calculates the residual heat energy of the engine 2 according to the approximate proportion of the residual heat energy, and finally can roughly calculate the final generating efficiency by taking the efficiency of the residual heat of the engine 2 in the power generation into consideration.

Secondly PLC control system 4 mainly monitors the operating mode of compressor 3, guarantees the safe operation of compressor 3, and this system is not only in order to utilize the waste heat maximize, and the while is mainly on waste heat utilization's basis, will guarantee the normal operating of compressor 3, and the main parameter that compressor 3 needs the monitoring is inlet pressure and discharge pressure, guarantees that inlet pressure value and discharge pressure value are in normal range, includes:

if the air inlet pressure value is lower than a first low-pressure set threshold value or higher than a first high-pressure set threshold value, emergency shutdown is carried out through the safety interlocking protection system ESD; if the air inlet pressure is higher than the first low pressure set threshold and lower than the normal range, the opening degree of an air inlet valve of the compressor 3 is increased to supplement the air inlet pressure; if the air inlet pressure is higher than the normal range and lower than the first high pressure setting threshold, the opening degree of an air inlet valve of the compressor 3 is reduced, and the air inlet pressure is reduced; that is, when the intake pressure is slightly lower or higher than the normal range, the intake pressure can be controlled by adjusting the opening of the intake valve of the compressor 3, but when the intake pressure is lower or higher, the compressor 3 is damaged by continuing to operate, and therefore, the ESD system is used for emergency shutdown.

If the exhaust pressure is lower than a second low-pressure set threshold or higher than a second high-pressure set threshold, emergency shutdown is carried out through ESD; if the exhaust pressure is higher than the second low pressure setting threshold and lower than the normal range, the rotation speed of the engine 2 is increased; if the exhaust pressure is higher than the normal range and lower than the second high pressure setting threshold, the engine 2 is reduced in rotation speed. Similarly, the compressor 3 is shut down at very low or very high discharge pressures, which are controlled by adjusting the speed of the transmitter if only slightly below or above the normal range value.

The PLC control system 4 monitors the output voltage, the output current and the frequency of a generator in the waste heat power generation system; when the output voltage and the frequency are ensured to be the mains supply standard, namely the output voltage is controlled to be 220V and the frequency is controlled to be 50Hz, the smoke gas inflow of the waste heat power generation system is increased, and the current is increased so as to increase the power generation power. Through the fluctuation of the transient voltage detected by the PLC, the flue gas flow is effectively controlled, the fluctuation rate of the transient voltage is ensured to be lower than 0.25%, the transient frequency adjustment rate is lower than 5%, and the distortion degree of the voltage waveform is lower than 3%.

The power consumption of the compressor 3 is also controlled through the PLC control system 4, the waste heat power generation system is adopted to supply power under the condition that the waste heat power generation electric quantity is enough, and if the power consumption of the compressor 3 is not enough, the power consumption is automatically switched to an external grid-connected power system.

The PLC control system 4 simultaneously controls the rotating speed of the engine 2, automatically adjusts the air-fuel ratio, the combustion advance angle, the high-temperature flue gas flow switch, the ORC system 6 and the load of the steam turbine power generation system 7. The PLC control system 4 monitors various parameters of the compressor 3 such as an air inlet pressure value, an exhaust pressure value, an air inlet temperature, an exhaust temperature, bearings and bearing bushes and ensures that the various parameters of the air inlet pressure value, the exhaust pressure value and the like are in a normal range.

The low-carbon emission type compressor 3 in the embodiment of the invention has the following working states: when the compressor 3 operates independently, a waste heat power generation system is not used, the compressor 3 can efficiently perform the whole natural gas compression process under the driving of the engine 2, and the flue gas flow regulating valve of the engine 2 of the compressor 3 is closed through the PLC; in the low-carbon emission mode, the engine 2 drives the compressor 3 to compress natural gas, the high-temperature waste gas of the engine 2 opens the flue gas flow regulating valve through the PLC control system 4, the high-temperature flue gas heats the organic heating medium or water through the water circulation heat exchanger 1, the heated medium drives the ORC system 6 or the steam turbine power generation system 7 to generate power, and the generated power is output externally.