Nature protection technologies

7.2. Application of expander-generating apparatuses in process of using the technological pressure drop at natural gas conveying

Part 7. ENERGY SAVING

7.2. Application of expander-generating apparatuses in process of using the technological pressure drop at natural gas conveying

Agababov V.S., Koryagin А.V.; MPEI(TU)

 Recently in the U.S., countries of the Western Europe and South-East Asia expander-generating apparatuses (EGAs) gained a wide application. They are installations which allow generating electricity and in some cases also generating heat and cold, using the technological pressure drop at natural gas conveying. Today there are more than 200 installations with the unit capacity from 250 to 7000 kW. The first operational experience of such apparatus is gained in our country at the installation, which includes two apparatuses EGA-5000 of the total capacity of 10 MW (two apparatuses by 5 MW each) and which successfully operates during 10 years at CHPP-21 of the JSC “Mosenergo". The installation with a nominal capacity of 11,5 MW is commissioned at Sredne-Uralskaya SDPP. Several apparatuses operate at power plants of the Republic of Belarus, including Lukomlskaya SDPP

Part 7. ENERGY SAVING

7.2. Application of expander-generating apparatuses in process of using the technological pressure drop at natural gas conveying

7.2.1. Physical bases and estimation of EGA operational efficiency

Agababov V.S., Koryagin А.V.; MPEI(TU)

As it is known, the underground layer of natural gas is of a high pressure. A high pressure of the layer is partially used for transportation of natural gas through the main pipelines at considerable distances to the consumption site. In case of gas combustion in the industry or in a life, its pressure should be considerably lowered in comparison with the pressure in the main pipelines. This decrease usually occurs due to throttling.

Part 7. ENERGY SAVING

7.2. Application of expander-generating apparatuses in process of using the technological pressure drop at natural gas conveying

7.2.2. The analysis of influence of different parameters on operation of expander and estimation of EGA capacity

Agababov V.S., Koryagin А.V.; MPEI(TU)

 To analyze the influence of different process parameters on expander operation, to calculate its specific work, the formula [1] can be used:

formula7.9.eng

where k —an adiabatic indicator; R — a gas constant, kJ/(kmole×K); рin and рout — gas pressure at the expander inlet and outlet, accordingly, MPa; Z — a factor, considering “the reality” of gas.

Part 7. ENERGY SAVING

7.2. Application of expander-generating apparatuses in process of using the technological pressure drop at natural gas conveying

7.2.3. Inclusion of EGA in heat flow diagrams of power plants

Agababov V.S., Koryagin А.V.; MPEI(TU)

 Let’s consider several general flow diagrams of EGA application at power plants. We’ll consider the cases when gas is heated only before the expander and EGA is included in the heat flow diagram of TPP.

Part 7. ENERGY SAVING

7.2. Application of expander-generating apparatuses in process of using the technological pressure drop at natural gas conveying

7.2.4. Application of the thermal pump for heating gas before the expander

Agababov V.S., Koryagin А.V.; MPEI(TU)

 A flow diagram of the installation, including EGA and the thermal pump, is shown further. We’d like to underline that the proposed flow diagram enables the installation to operate in the autonomous mode at the only presence of a low-potential source of heat. The installation operates as follows.

Part 7. ENERGY SAVING

7.2. Application of expander-generator sets, using technological pressure drop of the transported natural gas

References to § 7.2

Agababov V.S., Koryagin A.V.; MPEI (TU) 

  1. Vukalovich M.P. Engineering thermodynamics / M.P. Vukalovich, I.I. Novikov. M.: Energiya. 1968.
  2. Agababov V.S. Change of CPP capacity by including the expander-generator set in its thermal diagram / V.S. Agababov, E.K. Arakelyan, A.V. Koryagin // Izv. vuzov. Problems of power engineering. 2000. No. 1—2. p. 32—39.
  3. Agababov V.S. Determination of CPP capacity change by including the expander-generator set in its thermal diagram // Herald of MPEI. 2000. No. 2. p. 83—86.
  4. Agababov V.S. Determination of fuel saving at condensing power plant by including the expander-generator set in its thermal diagram // Izv. vuzov. Problems of power engineering. 1999. No. 12. p. 3—8.