Материал: Russian Journal of Building Construction and Architecture
Issue № 1 (41), 2019 |
ISSN 2542-0526 |
absorber the fire regenerator regenerated 10 m3/h of diethylene diglycol. This led to a high consumption of gas fuel. For the sake of optimization it was suggested that the consumption of diethylene diglycol was reduced and thus that of gas fuel for the fire regenerator.
7. Аnalytical comparison of the operating modes. For analytical comparison of the operating modes of a volume of gas fuel for a large and small consumption of diethylene diglycol let us calculate the consumption of gas fuel. The initial data for calculating the consumption of fuel gas for the fire regenerator for the consumption of DEG10 = 10 m3/h and the amount of fuel gas necessary to regenerate 2 m3/h of DEG, DEG2 are given in Table 3.
|
|
|
|
|
|
Таble 3 |
Initial calculation data |
|
|
|
|
||
|
|
|
|
|
|
|
Value |
Designation |
|
Size |
Values |
|
Value |
|
for DEG10 |
|
of DEG2 |
|||
|
|
|
|
|
||
|
|
|
|
|
|
|
Initial consumption of the heated DEG |
GDEG1 |
|
m3/h |
10 |
|
2 |
Теmperature of the surrounding air |
tн. в. |
|
0С |
|
−20 |
|
Coefficient of the air consumption |
αт |
|
–– |
|
1.02 |
|
for the burner |
|
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Heat capacity of saturated diethylene diglycol |
СSDEG |
|
kJ / kg×К |
|
2.85 |
|
|
|
|
|
|
|
|
Теmperature of SDEG at the vapour outlet |
t/ |
|
°С |
|
135 |
|
|
|
|
|
|
|
|
Теmperature of the diethylene diglycol solu- |
t// |
|
°С |
|
163 |
|
tion at the outlet of the vapour |
|
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Теmperature of the escaping gases |
tух |
|
°С |
|
420 |
|
|
|
|
|
|
|
|
Let us calculate the heat productivity of the vapour, kWatt:
QП GДЭГ СДЭГ t// – t/ GB СB , |
(1) |
where GDEG is the consumption of the heated DEG; СSDEG is the heat capacity of the SDEG; t// is the temperature of the diethylene diglycol solution at the outlet of the vapour; t/ is the temperature of the SDEG at the inlet of the vapour; GВ is the consumption of the escaping gases; СВ is the heat capacity of the escaping gases.
In order to calculate the heat of fuel combustion a number of parameters has to be determined [16]. The volume of the air that is theoretically needed for complete combustion of 1 m3 of fuel gas:
тл |
CO |
тл |
) 1.5H2S |
тл |
тл |
|
m |
тл |
тл |
, |
(2) |
|
V0 0.0476 0.5 (H2 |
|
|
2CH4 |
n |
4 |
Cn Hm |
O2 |
|||||
|
|
|
|
|
|
|
|
|
|
|
|
|
where H2, CO, H2S, CH4 are volumetric proportions of fuel gas.
25
1 m3 of
(3) The volume of carbon dioxide that is theoretically necessary for complete combustion of 1 m3 of gas fuel:
(4)
Then the volume of dry smoke gases in the combustion products during complete fuel combustion is given by the formula:
|
VСГ |
VN |
2 |
VCO |
т 1 V0 . |
|
(5) |
|||
|
|
|
2 |
|
|
|
|
|
|
|
The volume of water vapour is respectively: |
|
|
|
|
|
|
|
|||
|
тл |
|
|
тл |
|
m |
тл |
0.0161 тV0 |
, |
(6) |
VН2О 0.01 H2 |
2CH4 |
2 |
Cn Hm |
|||||||
|
|
|
|
|
|
|
|
|
|
|
where αm is the coefficient of air consumption in the burner. |
|
|
|
|||||||
Therefore the total volume of smoke gases is given by the formula: |
|
|
||||||||
|
|
VГ Vсг |
VH2O . |
|
|
(7) |
||||
For calculating the amount of heat released during the fuel combustion we calculate the lowest heat of fuel combustion using the formula:
|
Qнр 0.01 СiтлQнр , |
|
(8) |
|||||
|
|
|
|
|
|
i |
|
|
where Стл |
is the specific heat capacity of the fuel; |
|
Q р |
is the specific heat of the fuel com- |
||||
i |
|
|
|
|
н |
|
|
|
|
|
|
|
|
i |
|
|
|
bustion. |
|
|
|
|
|
|
|
|
Along with that the physical heat introduced with the fuel is |
|
|
||||||
|
QТЛ |
сCH4 |
tтл , |
|
(9) |
|||
where сCH4 |
is the specific heat capacity of methane; tтл is the temperature of the fuel gas |
|||||||
(15 °С). |
|
|
|
|
|
|
|
|
The physical heat introduced with the air is |
|
|
|
|
|
|
|
|
|
Qв.вн. тV0iв , |
|
|
(10) |
||||
where iв is the enthalpy of the atmospheric air. |
|
|
|
|
|
|
||
Therefore the available amount of heat of the fuel combustion is |
|
|||||||
|
Qр Qр Q |
|
Q |
. |
(11) |
|||
|
р |
н |
тл |
|
в.вн. |
|
|
|
26
Issue № 1 (41), 2019 |
ISSN 2542-0526 |
The adiabatic temperature of the fuel combustion determined using the method of sequential approximations:
tа |
|
|
|
|
|
|
Qpp |
|
. |
(12) |
|
VN |
CN |
2 |
VCO |
CCO |
VH |
OCH |
O VH CN |
m 1 V0Cв |
|||
2 |
|
2 |
2 |
2 |
2 |
2 |
2 |
|
|
||
The enthalpy of smoke gases at the outlet of the vapour is given by the formula:
iух VN |
JN |
2 |
VCO |
JCO |
VH |
O JH |
O т 1 V0Jв , |
(13) |
2 |
|
2 |
2 |
2 |
2 |
|
|
where JN2 ,JCO2 ,JH2O ,Jв are specific enthalpies of the elements included in the escaping gas
and air necessary for complete combustion of 1 m3 of fuel gas respectively. The thermal coefficient of the efficiency of the vapour is
|
|
iух |
|
|
|
, |
1 |
|
|
|
|
||
|
|
|||||
|
|
р |
|
|
||
|
|
Qр |
|
|
|
|
where is the coefficient of the efficiency of the vapour.
The heat capacity of the smoke gas in the temperature range (tа−tух) is
ср Qрр iух .
tа tух
The consumption of fuel gas considering the above formulas and calculations is
B Qп ср ух VГ
Qр
The results of the calculations are summarized in Table 4.
Results of the comparative calculation
(14)
(15)
(16)
Таble 4
Value |
Designation |
Size |
Values |
|
Value |
|
for DEG10 |
for DEG2 |
|||||
|
|
|
||||
|
|
|
|
|
|
|
Effective heat productivity of the vapour |
QП |
kWatt |
937.96 |
|
335.56 |
|
Тheoretical volume of the air necessary |
V0 |
m3/m3 |
|
9.52 |
||
for complete combustion of 1 m3 of fuel gas |
|
|||||
|
|
|
|
|
||
Volume of nitrogen theoretically necessary |
VN 2 |
m3/m3 |
|
7.52 |
||
for complete combustion of 1 m3 of fuel gas |
|
|||||
|
|
|
|
|
||
Volume of carbon dioxide theoretically necessary |
VCO2 |
m3/m3 |
|
1 |
||
for complete combustion of 1 m3 of fuel gas |
|
|||||
|
|
|
|
|
||
Volume of dry smoke gas in the combustion |
VСГ |
m3/m3 |
|
8.71 |
||
products of fuel |
|
|||||
|
|
|
|
|
||
|
|
|
|
|
|
|
27
Russian Journal of Building Construction and Architecture
|
|
|
|
End of Table 4 |
||
|
|
|
|
|
|
|
Value |
Designation |
Size |
Values |
|
Value |
|
for DEG10 |
for DEG2 |
|
||||
|
|
|
|
|||
|
|
|
|
|
|
|
Volume of water vapour |
VН2О |
m3/m3 |
|
1.15 |
|
|
Total volume of smoke gases |
V |
m3/m3 |
|
9.86 |
|
|
|
Г |
|
|
|
|
|
|
|
|
|
|
|
|
Lowest heat of fuel gas combustion |
Qнр |
MJ/m3 |
|
39.82 |
|
|
|
|
|
|
|
|
|
Physical heat introduced with fuel gas |
QТЛ |
MJ/m3 |
|
0.033 |
|
|
Physical heat introduced with the air |
Qв.вн. |
MJ/m3 |
|
−0.25 |
|
|
Available heat of fuel combustion |
Qрр |
MJ/m3 |
|
39.6 |
|
|
|
|
|
|
|
|
|
Аdiabatic temperature of fuel combustion |
tа |
°С/m3 |
|
1950 |
|
|
|
|
|
|
|
|
|
Enthalpy of smoke gases at the outlet of the vapour |
iух |
kJ/m3 |
|
8994 |
|
|
Тhermal coefficient of the efficiency of the vapour |
|
|
|
0.734 |
|
|
|
|
|
|
|
|
|
Тhermal capacity of smoke gases |
ср |
kJ/m3×К |
|
20 |
|
|
Fuel gas consumption |
В |
m3 |
0.0402 |
|
0.0183 |
|
Therefore for regenerating 10 m3/h of DEG 144ю72 m3/h of fuel gas is required and for regenerating 2 m3/h of DEG 65ю88 m3/h of fuel gas is required.
8. Technical and economic calculation. In order to determine the costs for regenerating glycol it is necessary to calculate what time (hours per year during a season) the fire regenerator operates, h/year:
rобщ zот.пер. 24 4344,
where zот.пер is the number of days of the heating season.
Then the total fuel gas consumption for regeneration of 2 m3/h of DEG during a heating season is, m3/year:
В2год В2 rобщ 286183,
where В2 is the consumption of fuel gas per second that is necessary for the regeneration of 2 m2/h of DEG; rобщ is the number of hours of the heating season.
Let us calculate the consumption of the fuel gas supplied into a flame tube for regenerating 2 m3/h of DEG, thousand rub/year:
ИТ2 Вгод2 ЦТ 396.8,
where Вгод2 is the total fuel gas consumption for regenerating 2 m3/h of DEG; ЦТ is the cost of the fuel gas (1.386 thousand rub/1000 m3).
28
Issue № 1 (41), 2019 |
ISSN 2542-0526 |
The total fuel gas consumption for regenerating 10 m3/h of DEG for the heating season is, m3/year:
Вгод10 В10 3600 rобщ 628664,
where В10 is the consumption of fuel gas necessary for regenerating 10 m3/h of DEG.
The costs of the fuel gas supplied into the flame tube for the combustion for regenerating 2 m3/h of DEG is, thousand rub/year:
ИТ10 Вгод10 ЦТ 871.643,
where Вгод10 is the total consumption of the fuel gas for regenerating 10 m3/h of DEG. Therefore the saved regeneration costs are, thousand rub/year:
И ИТ10 ИТ2 474.843.
Conclusions
1.An analytical analysis of the operation of the fire glycol regenerator for different operation modes (during loading of all the absorbers and of one absorber). The calculations of the economic efficiency showed that the reduction in the consumption of diethylene diglycol for regeneration allows around 470.000 rubles per collection season to be saved.
2.This operation mode can be achieved in two ways: by installing a by-pass line at the inlet pump and frequency controller at the inlet pump. The use of the first option would allow one to reduce the consumption of diethylene diglycol required for regeneration and the use of the second one, apart from reducing the consumption of diethylene diglycol, would provide a longer life cycle of the pump and trouble-free life.
References
1.Al'kin V. A., Iskhakov A. Ya., Kan V. E. Opredelenie optimal'nogo ob"ema zakachki gaza po skvazhinam pri ekspluatatsii gazokhranilishch (na primere Uvyazovskogo PKhG) [Determination of the optimal volume of injection gas wells in the operation of storage facilities (for example Vazovskogo UGS)]. Geologiya, geofizika i razrabotka neftyanykh i gazovykh mestorozhdenii, 2012, no. 2, pp. 58—61.
2.Shipovalov A. N., Zemenkov Yu. D., Toropov S. Yu., e. a. Aspekty tekhnologicheskoi nadezhnosti i ekonomicheskoi effektivnosti ekspluatatsii podzemnykh khranilishch prirodnogo gaza Zapadnoi Sibiri [Aspects of technological reliability and economic efficiency of operation of underground natural gas storage facilities in Western Siberia]. Tyumen, Neftegazovyi universitet, 2012. 364 p.
3.Berezhnaya, E. V., Berezhnoi V. I. Matematicheskie metody modelirovaniya ekonomicheskikh sistem [Mathematical methods of economic systems modeling]. Moscow, Finansy i statistika Publ., 2001. 268 p.
4.Buzinov, S. N., Tolkushin G. F. Metody optimizatsii tekhnologicheskikh parametrov PKhG [Methods of optimization of technological parameters of UGS]. Transport i khranenie gaza, 1979, no. 8, pp. 21—28.
29