CN117989520A - Calculation method and system for energy control of excess steam of auxiliary boiler of ship - Google Patents

Abstract

The calculation method for the excess steam energy control of the auxiliary boiler of the ship comprises the following steps of: step one, installing a vortex shedding flowmeter at an outlet pipeline of a steam valve of a boiler, and installing a signal isolator and a signal collector on the boiler; step two, firstly starting the boiler, monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector, and starting to calculate excessive steam discharge when the steam flow is larger than a preset value Qstm; and step three, when the boiler is in an excessive state, the excessive steam valve is opened, the steam is in a discharging state, and early warning and boiler load adjustment or excessive setting are carried out at the same time. The invention adopts a mode of combining the flowmeter with the opening signal, has the advantages that the flow is converted through the K opening signal for small flow, the measurable flow is controlled, the flowmeter is used for measuring, and the calculation result is more accurate and more fits the actual value.

Description

Calculation method and system for energy control of excess steam of auxiliary boiler of ship

Technical Field

The invention relates to an improvement of a ship auxiliary boiler technology, belongs to the field of ship boilers, and particularly relates to a calculation method and a system for controlling excessive steam energy of a ship auxiliary boiler.

Background

The auxiliary boiler is a boiler for supplying auxiliary machinery, equipment and household miscellaneous steam on a diesel engine ship, when the steam quantity generated by the boiler is larger than the steam quantity required by equipment consumption under certain working conditions, an excessive steam valve is arranged on a steam pipeline to protect the boiler from overpressure, when the steam pressure of the boiler is higher than the set value of the excessive steam valve, the excessive steam valve is automatically opened to release the excessive steam, the pressure of the boiler is ensured not to exceed the set pressure, in the actual operation of the ship, the excessive steam valve of the auxiliary boiler is often opened for various reasons, and the steam directly enters a condenser to be condensed, so that energy waste is caused. At present, boiler load or excessive steam setting depends on the experience of a shipman, and energy waste caused by excessive steam discharge is not enough.

The Chinese patent application with the application number of CN202111154864.5 and the application date of 2021, 9 and 29 discloses a steam flow monitoring method and a device, which are applied to a power plant comprising a steam supply pipeline, wherein the steam supply pipeline is provided with a thermal resistor and a vortex shedding flowmeter, and the method comprises the following steps: acquiring a steam drum temperature value in a user sub-cylinder and a steam instantaneous flow value in the steam supply pipeline in real time, and transmitting the acquired steam drum temperature value and the acquired instantaneous flow value to the flow integrating instrument; determining the steam utilization state of a user according to the steam drum temperature value; determining a steam flow used by the user based on the instantaneous flow value and the user steam state; wherein, the thermal resistor is used for detecting the steam drum temperature. Thus, the steam flow used by the user is metered when the lower limit of the measurable quantity of the vortex shedding flowmeter is ensured, but the problem that excessive steam discharge cannot be controlled is not solved by the technology.

The disclosure of this background section is only intended to increase the understanding of the general background of the present patent application and should not be taken as an admission or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

Disclosure of Invention

The invention aims to solve the problem that excessive steam discharge cannot be controlled in the prior art, and provides a calculation method and a system for controlling excessive steam energy of a ship auxiliary boiler, wherein the excessive steam discharge can be controlled.

In order to achieve the above object, the technical solution of the present invention is: the calculation method for the excess steam energy control of the auxiliary boiler of the ship comprises the following steps of:

Step one, installing a vortex shedding flowmeter at an outlet pipeline of a steam valve of a boiler, and installing a signal isolator and a signal collector on the boiler;

step two, firstly starting the boiler, monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector, and starting to calculate excessive steam discharge when the steam flow is larger than a preset value Qstm;

and step three, when the boiler is in an excessive state, the excessive steam valve is opened, the steam is in a discharging state, and early warning and boiler load adjustment or excessive setting are carried out at the same time.

The calculation method for the excess steam energy control of the auxiliary boiler of the ship further comprises the following steps: and calculating excessive steam discharge in the time at each preset time interval to obtain fuel waste caused by corresponding steam discharge, accumulating fuel waste caused by all steam discharge, and obtaining statistics results of the excessive steam discharge and the fuel waste of the boiler operation after the operation of the boiler is finished.

The first step also comprises the step of installing a pressure sensor, a vortex shedding flowmeter and a mass flowmeter on a steam conveying main pipe of the boiler.

The signal isolator is used for collecting and converting an excessive steam valve opening feedback electric signal into an opening signal on the basis that the original excessive steam valve opening control function is not affected;

the signal collector acquires a boiler operation state signal sent by a boiler control system through a Modbus protocol;

the vortex shedding flowmeter is used for measuring the flow of steam generated by the operation of the boiler;

The mass flowmeter is used for collecting the fuel consumption of the boiler during operation;

the excess steam bleed calculation formula is as follows:

Q_du＝Q_stm×h_sat,st1

Wherein Q _du is the heat taken away by excessive steam, kJ/h; q _stm -excess steam discharge flow, kg/h;

h _sat,st1 -saturated steam enthalpy, kJ/kg; the pressure before the discharge valve is the header steam pressure P1.

The starting calculation of the excess steam bleed is specifically:

S1, calculating the boiler operation state through Boiler1 Runing and Boiler2 Runing, wherein Boiler1 Runing =1 or Boiler2 Runing =2, and determining that the boiler is operated;

S2, under the running state, monitoring Q _{Excess of} and the converted flow valve opening K, and calculating Q _{Excess of real}:

if Q _{Excess of} and K are equal to 0, Q _{Excess of real} =0;

If Q _{Excess of} ＞0,Q _{Excess of real}＝Q _{Excess of} ;

If Q _{Excess of} =0, K is greater than 0, Q _{Excess of real} =f (K);

wherein the function f (K) is a second-order least squares fitting function;

When S3 and Q _{Excess of real} are larger than 0, calculating excessive steam release heat Q _du through h _sat,st and Q _{Excess of real};

Wherein Q _du＝Q _{Excess of real}×h_sat,st represents heat waste per unit time;

When S4 and Q _{Excess of real} are larger than 0, calculating excessive steam fuel flow B _{Excess of} through Q _{Steam generation} , B and Q _{Excess of real},

Wherein B _{Excess of} ＝B/Q _{Steam generation} ×Q _{Excess of real} represents fuel waste per unit time;

S5, in one operation period, calculating total heat waste W and total fuel waste M, wherein W is the sampling period, and W is the total heat waste W and the total fuel waste M, and W is the total heat waste W.

The conventional flow Q is monitored through the flowmeter, the measuring range is 2.14-21.43t/h, the opening K of the flow valve is monitored, when the flow is smaller than 2.14t/h, the flowmeter cannot acquire flow data, and the flow data is converted through the opening K.

The method comprises the steps of obtaining an excessive steam valve opening electric signal, wherein the electric signal is recorded as I, and the converted opening signal is recorded as K;

The conversion formula of the opening degree K of the flow valve is as follows:

K＝(I-4)/16*100。

The method for calculating the consumed fuel oil comprises the following steps:

b₂＝b₁×Q_stm

Wherein the boiler fuel consumption B (kg/h) during the duty cycle is collected, the steam flow during this time is Qfw (kg/h), the fuel required for the steam flow is b1=b/Qfw, and the excess steam flow is known as Q _stm.

The calculation system comprises a flow module, an analog input module, a calculation module, an early warning module and a statistics module;

The flow module is used for monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector;

The analog quantity input module is used for acquiring the acquired electric signals of the opening degree of the excessive steam valve;

the calculation module is used for calculating the excessive steam flow;

the early warning module is used for opening the excessive steam valve when the steam valve is in an excessive state, carrying out early warning when the steam valve is in a discharging state, and simultaneously carrying out early warning and adjusting the load of the boiler or excessive setting;

The statistics module is used for counting the statistics results of excessive steam discharge and fuel waste of the boiler operation.

Compared with the prior art, the invention has the beneficial effects that:

1. The invention relates to a calculation method and a system for controlling excess steam energy of a ship auxiliary boiler, wherein a vortex shedding flowmeter is arranged at an outlet pipeline of a steam valve of the boiler, and a signal isolator and a signal collector are arranged on the boiler; when the steam flow is larger than a preset value Qstm, the excessive steam discharge is calculated, and the measuring position is at the valve body and the outlet of the excessive steam valve of the boiler, and the measuring method adopts a mode of combining the flow meter and the opening signal. Therefore, the steam flow can be controlled, the calculation result is more accurate, and the actual value is more attached.

2. According to the calculation method and the system for the energy control of the excessive steam of the auxiliary boiler of the ship, disclosed by the invention, the energy and the fuel oil wasted by excessive steam discharge are calculated through monitoring, so that a user is reminded of paying attention to the reasonable use of the steam of the boiler during use, the waste is reduced, and the energy is saved. Therefore, the invention can provide early warning and save energy.

3. According to the calculation method and the calculation system for the excess steam energy control of the auxiliary boiler of the ship, the whole flow is detected once every thirty minutes, the frequency is better, the change display is more timely, and the statistical accuracy is further improved. Therefore, the invention has faster statistical frequency and higher accuracy.

Drawings

FIG. 1 is a schematic representation of a flow-opening curve of the present invention.

Fig. 2 is a schematic diagram of steam pressure-excess steam bleed in the present invention.

Fig. 3 is a block diagram of the structure of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings and detailed description.

Referring to fig. 1 to 3, a method for calculating excess steam energy control of a ship auxiliary boiler includes the steps of:

Step one, installing a vortex shedding flowmeter at an outlet pipeline of a steam valve of a boiler, and installing a signal isolator and a signal collector on the boiler;

step two, firstly starting the boiler, monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector, and starting to calculate excessive steam discharge when the steam flow is larger than a preset value Qstm;

and step three, when the boiler is in an excessive state, the excessive steam valve is opened, the steam is in a discharging state, and early warning and boiler load adjustment or excessive setting are carried out at the same time.

The calculation method for the excess steam energy control of the auxiliary boiler of the ship further comprises the following steps: and calculating excessive steam discharge in the time at each preset time interval to obtain fuel waste caused by corresponding steam discharge, accumulating fuel waste caused by all steam discharge, and obtaining statistics results of the excessive steam discharge and the fuel waste of the boiler operation after the operation of the boiler is finished.

The first step also comprises the step of installing a pressure sensor, a vortex shedding flowmeter and a mass flowmeter on a steam conveying main pipe of the boiler.

The signal isolator is used for collecting and converting an excessive steam valve opening feedback electric signal into an opening signal on the basis that the original excessive steam valve opening control function is not affected;

the signal collector acquires a boiler operation state signal sent by a boiler control system through a Modbus protocol;

the vortex shedding flowmeter is used for measuring the flow of steam generated by the operation of the boiler;

The mass flowmeter is used for collecting the fuel consumption of the boiler during operation;

the excess steam bleed calculation formula is as follows:

Q_dx＝Q_stm×h_sat,st1

Wherein Q _du is the heat taken away by excessive steam, kJ/h; q _stm -excess steam discharge flow, kg/h;

h _sat,st1 -saturated steam enthalpy, kJ/kg; the pressure before the discharge valve is the header steam pressure P1.

The starting calculation of the excess steam bleed is specifically:

S1, calculating the boiler operation state through Boiler1 Runing and Boiler2 Runing, wherein Boiler1 Runing =1 or Boiler2 Runing =2, and determining that the boiler is operated;

S2, under the running state, monitoring Q _{Excess of} and the converted flow valve opening K, and calculating Q _{Excess of real}:

if Q _{Excess of} and K are equal to 0, Q _{Excess of real} =0;

If Q _{Excess of} ＞0,Q _{Excess of real}＝Q _{Excess of} ;

If Q _{Excess of} =0, K is greater than 0, Q _{Excess of real} =f (K);

wherein the function f (K) is a second-order least squares fitting function;

When S3 and Q _{Excess of real} are larger than 0, calculating excessive steam release heat Q _du through h _sat,st and Q _{Excess of real};

Wherein Q _du＝Q _{Excess of real}×h_sat,st represents heat waste per unit time;

When S4 and Q _{Excess of real} are larger than 0, calculating excessive steam fuel flow B _{Excess of} through Q _{Steam generation} , B and Q _{Excess of real},

Wherein B _{Excess of} ＝B/Q _{Steam generation} ×Q _{Excess of real} represents fuel waste per unit time;

S5, in one operation period, calculating total heat waste W and total fuel waste M, wherein W is the sampling period, and W is the total heat waste W and the total fuel waste M, and W is the total heat waste W.

The conventional flow Q is monitored through the flowmeter, the measuring range is 2.14-21.43t/h, the opening K of the flow valve is monitored, when the flow is smaller than 2.14t/h, the flowmeter cannot acquire flow data, and the flow data is converted through the opening K.

The method comprises the steps of obtaining an excessive steam valve opening electric signal, wherein the electric signal is recorded as I, and the converted opening signal is recorded as K;

The conversion formula of the opening degree K of the flow valve is as follows:

K＝(I-4)/16*100。

The method for calculating the consumed fuel oil comprises the following steps:

b₂＝b₁×Q_stm

Wherein the boiler fuel consumption B (kg/h) during the duty cycle is collected, the steam flow during this time is Qfw (kg/h), the fuel required for the steam flow is b1=b/Qfw, and the excess steam flow is known as Q _stm.

The calculation system comprises a flow module, an analog input module, a calculation module, an early warning module and a statistics module;

The flow module is used for monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector;

The analog quantity input module is used for acquiring the acquired electric signals of the opening degree of the excessive steam valve;

the calculation module is used for calculating the excessive steam flow;

the early warning module is used for opening the excessive steam valve when the steam valve is in an excessive state, carrying out early warning when the steam valve is in a discharging state, and simultaneously carrying out early warning and adjusting the load of the boiler or excessive setting;

The statistics module is used for counting the statistics results of excessive steam discharge and fuel waste of the boiler operation.

The computing system also includes a resistance module.

The principle of the invention is explained as follows: the energy loss of the excessive steam flow in one working period of the boiler is monitored, the excessive steam energy waste is prompted, and the excessive steam fuel waste condition in one working period is analyzed.

Example 1:

The calculation method for the excess steam energy control of the auxiliary boiler of the ship comprises the following steps of:

Step one, installing a vortex shedding flowmeter at an outlet pipeline of a steam valve of a boiler, and installing a signal isolator and a signal collector on the boiler;

Step two, starting the boiler, monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector, and starting to calculate excessive steam discharge when the steam flow is larger than a preset value Qstm;

Step three, when the steam valve is in an excessive state, the excessive steam valve is opened, the steam is in a discharging state, and early warning is carried out and the load of the boiler or excessive setting is adjusted;

And step four, calculating excessive steam discharge once every 30 minutes to obtain fuel waste caused by corresponding steam discharge, accumulating fuel waste caused by all steam discharge, and obtaining statistics results of the excessive steam discharge and the fuel waste of the boiler operation after the operation of the boiler is finished.

Example 2:

example 2 is substantially the same as example 1 except that:

the excess steam bleed calculation formula is as follows:

Q_du＝Q_stm×h_sat,st1

Wherein Q _du is the heat taken away by excessive steam, kJ/h; q _stm -excess steam discharge flow, kg/h;

h _sat,st1 -saturated steam enthalpy, kJ/kg; the pressure before the discharge valve is the header steam pressure P1.

The starting calculation of the excess steam bleed is specifically:

S1, calculating the boiler operation state through Boiler1 Runing and Boiler2 Runing, wherein Boiler1 Runing =1 or Boiler2 Runing =2, and determining that the boiler is operated;

S2, under the running state, monitoring Q _{Excess of} and the converted flow valve opening K, and calculating Q _{Excess of real}:

if Q _{Excess of} and K are equal to 0, Q _{Excess of real} =0;

If Q _{Excess of} ＞0,Q _{Excess of real}＝Q _{Excess of} ;

If Q _{Excess of} =0, K is greater than 0, Q _{Excess of real} =f (K);

wherein the function f (K) is a second-order least squares fitting function;

When S3 and Q _{Excess of real} are larger than 0, calculating excessive steam release heat Q _du through h _sat,st and Q _{Excess of real};

Wherein Q _du＝Q _{Excess of real}×h_sat,st represents heat waste per unit time;

When S4 and Q _{Excess of real} are larger than 0, calculating excessive steam fuel flow B _{Excess of} through Q _{Steam generation} , B and Q _{Excess of real},

Wherein B _{Excess of} ＝B/Q _{Steam generation} ×Q _{Excess of real} represents fuel waste per unit time;

S5, in one operation period, calculating total heat waste W and total fuel waste M, wherein W is the sampling period, and W is the total heat waste W and the total fuel waste M, and W is the total heat waste W.

The conventional flow Q is monitored through the flowmeter, the measuring range is 2.14-21.43t/h, the opening K of the flow valve is monitored, when the flow is smaller than 2.14t/h, the flowmeter cannot acquire flow data, and the flow data is converted through the opening K;

The flowmeter collects flow, which is marked as Q _{Acquisition of} , and when Q _{Acquisition of} is smaller than a small flow limit value Q _min, the small flow limit value Q _min is used as actual flow; when Q _{Acquisition of} is larger than the large flow rate limit value Q _max, 2×q _{Acquisition of} is used as the actual flow rate, and when Q _min＜Q _{Acquisition of} ＜Q_max, Q _{Acquisition of} is used as the line flow rate.

The method comprises the steps of obtaining an excessive steam valve opening electric signal, wherein the electric signal is recorded as I, and the converted opening signal is recorded as K;

The conversion formula of the opening degree K of the flow valve is as follows:

K＝(I-4)/16*100。

The method for calculating the consumed fuel oil comprises the following steps:

b₂＝b₁×Q_stm

Wherein the boiler fuel consumption B (kg/h) during the duty cycle is collected, the steam flow during this time is Qfw (kg/h), the fuel required for the steam flow is b1=b/Qfw, and the excess steam flow is known as Q _stm.

The fitting curves of the opening and the flow are as follows, different valve head designs can influence the curve condition of the valve, and for the control valve, the Q-K (flow-opening) curve is designed as a percentage curve as shown in figure 1, namely, the ratio between the maximum flow percentage Q/Qmax% and the opening K/Kmax% is equal to the opening K/Kmax%, namely, Q and K2 form a linear relation;

the second-order least square fitting is selected to calculate the Q-K relation, and the formula is as follows: yi=α+Φxxi+ζxxi.

Example 3:

Example 3 is substantially the same as example 1 except that:

the calculation system comprises a flow module, an analog input module, a calculation module, an early warning module and a statistics module;

The flow module is used for monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector;

The analog quantity input module is used for acquiring the acquired electric signals of the opening degree of the excessive steam valve;

the calculation module is used for calculating the excessive steam flow;

the early warning module is used for opening the excessive steam valve when the steam valve is in an excessive state, carrying out early warning when the steam valve is in a discharging state, and simultaneously carrying out early warning and adjusting the load of the boiler or excessive setting;

The statistics module is used for counting the statistics results of excessive steam discharge and fuel waste of the boiler operation.

The calculation system also comprises a resistance module, when the boiler calculation system does not have a data interface for providing an operation state signal, the pressure of the boiler steam main pipe can be measured through a pressure sensor arranged on the boiler steam conveying main pipe, and the operation of the boiler can be judged through the rising of the steam pressure; the resistance sensor can be arranged on the relay contact for starting control of the two boilers, and the boiler operation can be judged through the reduction of the resistance value.

The above description is merely of preferred embodiments of the present invention, and the scope of the present invention is not limited to the above embodiments, but all equivalent modifications or variations according to the present disclosure will be within the scope of the claims.

Claims (10)

1. A calculation method for controlling excess steam energy of a ship auxiliary boiler is characterized by comprising the following steps of: the calculation method for the energy control of the excess steam of the auxiliary boiler of the ship comprises the following steps:

Step one, installing a vortex shedding flowmeter at an outlet pipeline of a steam valve of a boiler, and installing a signal isolator and a signal collector on the boiler;

step two, firstly starting the boiler, monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector, and starting to calculate excessive steam discharge when the steam flow is larger than a preset value Qstm;

and step three, when the boiler is in an excessive state, the excessive steam valve is opened, the steam is in a discharging state, and early warning and boiler load adjustment or excessive setting are carried out at the same time.

2. The method for calculating excess steam energy control of a marine auxiliary boiler according to claim 1, wherein: the calculation method for the excess steam energy control of the auxiliary boiler of the ship further comprises the following steps: and calculating excessive steam discharge in the time at each preset time interval to obtain fuel waste caused by corresponding steam discharge, accumulating fuel waste caused by all steam discharge, and obtaining statistics results of the excessive steam discharge and the fuel waste of the boiler operation after the operation of the boiler is finished.

3. The method for calculating excess steam energy control of a marine auxiliary boiler according to claim 1, wherein: the first step also comprises the step of installing a pressure sensor, a vortex shedding flowmeter and a mass flowmeter on a steam conveying main pipe of the boiler.

4. A method of computing excess steam energy control for a marine auxiliary boiler as claimed in claim 3, wherein: the signal isolator is used for collecting and converting an excessive steam valve opening feedback electric signal into an opening signal on the basis that the original excessive steam valve opening control function is not affected;

the signal collector acquires a boiler operation state signal sent by a boiler control system through a Modbus protocol;

the vortex shedding flowmeter is used for measuring the flow of steam generated by the operation of the boiler;

the mass flowmeter is used for collecting the fuel consumption of the boiler during operation.

5. The method for calculating excess steam energy control of a marine auxiliary boiler according to claim 1, wherein: the excess steam bleed calculation formula is as follows:

Q_du＝Q_stm×h_sat,st1

Wherein Q _du is the heat taken away by excessive steam, kJ/h; q _stm -excess steam discharge flow, kg/h;

h _sat,st1 -saturated steam enthalpy, kJ/kg; the pressure before the discharge valve is the header steam pressure P1.

6. The method for calculating excess steam energy control of a marine auxiliary boiler according to claim 5, wherein: the starting calculation of the excess steam bleed is specifically:

s1, calculating the boiler operation state through Boiler1 Runing and Boiler2 Runing, wherein Boiler1 Runing =1 or Boiler2 Runing =2, and determining that the boiler is operated;

S2, under the running state, monitoring Q _{Excess of} and the converted flow valve opening K, and calculating Q _{Excess of real}:

if Q _{Excess of} and K are equal to 0, Q _{Excess of real} =0;

If Q _{Excess of} ＞0,Q _{Excess of real}＝Q _{Excess of} ;

If Q _{Excess of} =0, K is greater than 0, Q _{Excess of real} =f (K);

wherein the function f (K) is a second-order least squares fitting function;

When S3 and Q _{Excess of real} are larger than 0, calculating excessive steam release heat Q _du through h _sat,st and Q _{Excess of real};

wherein Q _du＝Q _{Excess of real}×h_sat,st represents heat waste per unit time;

When S4 and Q _{Excess of real} are larger than 0, calculating excessive steam fuel flow B _{Excess of} through Q _{Steam generation} , B and Q _{Excess of real},

Wherein B _{Excess of} ＝B/Q _{Steam generation} ×Q _{Excess of real} represents fuel waste per unit time;

And S5, calculating total heat waste W and total fuel waste M in one operation period, wherein W=ΣQ _du×Δt,M＝ΣB _{Excess of} ×Δt, and Δt is a sampling period.

7. The method for calculating excess steam energy control of a marine auxiliary boiler according to claim 6, wherein: the conventional flow Q is monitored through the flowmeter, the measuring range is 2.14-21.43 t/h, the opening K of the flow valve is monitored, when the flow is smaller than 2.14t/h, the flowmeter cannot acquire flow data, and the flow data is converted through the opening K.

8. The method for calculating excess steam energy control of a marine auxiliary boiler according to claim 7, wherein: the method comprises the steps of obtaining an excessive steam valve opening electric signal, wherein the electric signal is recorded as I, and the converted opening signal is recorded as K;

The conversion formula of the opening degree K of the flow valve is as follows:

K＝(I-4)/16*100。

9. the method for calculating excess steam energy control of a marine auxiliary boiler according to claim 1, wherein: the method for calculating the consumed fuel oil comprises the following steps:

b₂＝b₁×Q_stm

Wherein the boiler fuel consumption B (kg/h) during the duty cycle is collected, the steam flow during this time is Qfw (kg/h), the fuel required for the steam flow is b1=b/Qfw, and the excess steam flow is known as Q _stm.

10. A computing system for marine vessel auxiliary boiler excess steam energy management as defined in claim 1, wherein: the computing system comprises a flow module, an analog input module, a computing module, an early warning module and a statistics module;

The flow module is used for monitoring the excessive steam flow of the boiler through the vortex shedding flowmeter, the signal isolator and the signal collector;

The analog quantity input module is used for acquiring the acquired electric signals of the opening degree of the excessive steam valve;

the calculation module is used for calculating the excessive steam flow;

the early warning module is used for opening the excessive steam valve when the steam valve is in an excessive state, carrying out early warning when the steam valve is in a discharging state, and simultaneously carrying out early warning and adjusting the load of the boiler or excessive setting;

The statistics module is used for counting the statistics results of excessive steam discharge and fuel waste of the boiler operation.