ON THE QUESTION OF TECHNOLOGICAL PROGRESS IN THE ENERGY SECTOR

S. V. Polozhii

(Presented by the scientific seminar of the Department of TPP)

The development of the energy sector over the last 15–20 years and forecasting for the next 10–15 years are characterized by a weak conception of the actual results of technological progress and of the realistically achievable effect from the introduction and assimilation of new technology.

The transition to unit thermal power plants with the traditional cycle at steam parameters of 300–350 ata, 600–650°C fifteen years ago in the USA proved unjustified in terms of techno-economic and operating indicators, reliability of operation, and the advisability of using such units in power systems. The transition to such units turned out to be an erroneous decision. In the subsequent period, the US energy sector shifted to the construction of genuinely efficient large-capacity units with steam parameters low relative to the preceding units—160–240 ata, 540–540°C. These units were successfully mastered in a short time, the design indicators were successfully achieved, and over the last decade the energy sector was completely transferred to such steam parameters, with a continuous increase in unit capacity up to 800–1200 MW in recent years. The development of the energy sector in other countries of the world followed the same path. At this level of initial parameters and thermal efficiency, the development of large unit thermal power plants in the world energy sector became conserved. Thus, in practice, the limit of increasing the thermal economy of power units—of further technological progress in steam-turbine thermal power plants with the traditional cycle—was reached in the first field. During this period of energy development, there was a complete collapse of forecasts and notions regarding the high possibilities of technological progress in raising the initial parameters and thermal economy of unit thermal power plants.

The complete unexpectedness of the negative results and low capabilities of unit thermal power plants, and the erroneousness of the initial technical decisions, proved to be a characteristic feature of the development of the energy sector with the traditional cycle in the second field over the past decade and a half. The transition to 300 MW supercritical-pressure units also turned out to be unforeseen in terms of the difficulties and time required to master such units in the domestic energy sector. After 6–7 years of operation of such supercritical-pressure units, a decision was made and a broad program of research, design, engineering, and industrial measures was outlined to improve the reliability and economy of K-300-240 supercritical-pressure units in our country [1].

In contemporary scientific and technical literature, no explanation is found and the fundamental causes are not disclosed for the unsatisfactory development of unit power engineering, for the adoption of erroneous decisions and forecasts, for the failure to foresee the low real possibilities of increasing the thermal efficiency of power plants by means of modern generating units, and for the economic inexpediency and operational unsuitability of introducing such new technology. Nor are the actual causes explained for the stagnation and decline in the thermal efficiency of U.S. power systems over the last 7–8 years, which have completely switched to the technically most advanced, highly economical, and reliable large units, instead of the planned fuel savings at U.S. power plants from the introduction of such units.

The development of world power engineering over the last decade and a half to two decades, as studies by the TPI show [2–4], has proceeded in accordance with the objective properties and laws of the traditional cycle used in power engineering, with its actual real possibilities for ensuring technical progress in steam-turbine thermal power plants, and fully reflects the degradation of the traditional cycle of the second region at the present stage of development of unit power engineering.

The development of power engineering in the pre-unit period was based on the use of the traditional cycle of the first region. A feature of the development of power engineering in this period is the unambiguous dependence of technical progress in power engineering on the value of the thermal efficiency of the cycle of the first region. The transition to higher steam parameters and the increase in the thermal efficiency of the cycle completely determined technical progress in power engineering: fuel savings at thermal power plants and in power systems, a reduction in the cost of producing electric power and an increase in the overall efficiency of power engineering, a reduction in initial and current investments in power engineering, and a more intensive increase in capacity and in the production of electric power. This long period in the development of power engineering was wholly determined by the task of saving fuel at thermal power plants by increasing the thermal efficiency of the traditional cycle of the first region. At the same time, all other aspects of technical progress in power engineering were solved automatically. The unit capacity and duty of power equipment increased; initial and current capital investments for the construction and operation of thermal power plants with higher steam parameters decreased; the cost of producing electric power decreased. Operating conditions improved, the efficiency of the operation of thermal power plants and power systems increased, and the reliability and maneuverability of power-system operation rose. An objective law of development of the traditional cycle of the first region was in effect. For decades, the all-embracing role and significance of thermal efficiency and the reduction of specific fuel consumption for technical progress in power engineering, and the leading role of thermodynamics in the development of power engineering, were confirmed. At the same time, within this period the transition to a higher level of parameters did not require changing the cycle itself or the technological scheme of the thermal power plant, the development of essentially new power equipment, or the manufacture of special steels; there were no substantial changes in the thermodynamic, heat-engineering, and thermophysical properties of water and steam, in the conditions of generation of the working fluid, or in its operation in the steam turbine.

The operating conditions of new thermal power plants did not change for the worse either in terms of commissioning time, or in operating modes and reliability. For these reasons, forecasting in power engineering was limited to the values of the thermal efficiency of new thermal power plants. There was no need to use the method of reduced total costs in techno-economic justifications, nor was there a need to develop such a method, just as there was no need for a third stage of forecasting according to the conditions of commissioning and operation.

new thermal power stations. During this period, the exceptional role of the thermodynamic efficiency of the cycle in the progress of power engineering, and the need for an all-round increase in the thermal efficiency of the cycle for the development of power engineering, becomes established in the consciousness of power engineers. The chief shortcoming and contradiction of the traditional cycle of the first region is its unsuitability for concentrating the unit capacities of thermal power-station units and the low absolute economy of thermal power stations with the traditional cycle of the first region, its incompatibility with the tasks and requirements of the present stage of development of power engineering, and with the enormous rates and scales of development of thermal power stations and of electric-power production, without which technical progress in all branches of industry in the developed countries of the world is impossible. This is the degradation of the traditional cycle of the first region, which occurred one and a half to two decades ago, its inability to ensure further progress in power engineering and to raise the technical level of development of steam-turbine thermal power stations of low capacity. This is the reason for the transition of power engineering also to the use of the traditional cycle of the second region in world power engineering.

The United States headed this new direction in the development of power engineering and began to implement it with the introduction of powerful power units at very high supercritical steam parameters of 300–350 ata, 600–650°C. However, the transition to such steam parameters in unit thermal power stations was based on a thermodynamic concept: the desire to realize the maximum value of the thermal efficiency with the intention of subsequently moving to still higher initial steam parameters and complex heat schemes up to 400–500 ata, 700–750°C. This initial stage in the development of unit thermal power stations with the traditional cycle of the second region in the United States was not preceded by theoretical investigations of the properties and regularities of this cycle. There was not even any idea of organizing research in this respect. In the transition to the construction of powerful unit thermal power stations with the traditional cycle of the second region, the peculiarities and regularities of the traditional cycle of this region were not clarified. In view of this, the fundamental differences and principal features of the development of unit thermal power stations and of technical progress with the traditional cycle of the second region remained unexplained. The thermodynamic concept proved unsuitable for the development of technical progress in power engineering with unit thermal power stations of supercritical and super-supercritical pressure. From a positive leading factor in the development of power engineering with the traditional cycle of the first region, it becomes a negative one in the second region. A considerable increase in the thermal efficiency leads to the technical-economic inexpediency of such installations with the traditional cycle of the second region, to the impossibility of technically implementing and mastering such thermal electric stations, and to enormous losses in power engineering in the development and introduction of such thermal power stations. Instead of a reduction in the reduced total costs of producing electric energy from increasing the thermal efficiency of the cycle of the first region, there is an increase in these costs as the thermal efficiency of installations with the traditional cycle of the second region is raised. Material costs and the cost of producing electric energy increase from raising the thermal efficiency in such installations. The high mobility and load-following capability of power stations of the thermodynamic cycle of the first region are accompanied by the loss of these most important properties of thermal power stations with an increase in $\eta_t$ of the traditional cycle of the second region. Instead of preserving the favorable physical, thermodynamic, and heat-engineering properties of water and water vapor when $\eta_t$ is increased in installations with a cycle of the first region, there is a sharp deterioration of these properties with increasing thermal efficiency in installations with the traditional cycle of the second region.

Along with this, fundamental changes occur in the thermodynamic cycle, and in the heat and technological scheme, from \(\eta_t\) in installations of the second region. Intermediate superheating of steam is introduced, the scheme of regenerative heating of feedwater becomes more complicated, chemicalization of installations is introduced, as well as upgrading of condensate and feedwater to remove soluble salts and metals, and chemical treatment of power equipment throughout the entire technological scheme. The problem arose of creating high-quality metal and power equipment, and it becomes the more complex the higher the thermodynamic efficiency of installations with a cycle of the second region. The good compatibility of the operation of thermal power plants with the conditions and requirements of power systems—thermal power plants with a thermodynamic cycle of the first region—was replaced by the complete incompatibility of the operation of units in power systems in the variable part of load curves. The absence of the problem of covering peak load in power systems with thermal power plants with the traditional cycle of the first region became the main problem of operating power systems with unit-type thermal power plants with a cycle of the second region, and one all the more complex and difficult to solve as the thermal efficiency of such units increased. The absence of the problem of reliability of power-system operation in the past became the main problem of operating power systems with installations having the traditional cycle of the second region. Forecasting and determining technological progress by thermal efficiency led to erroneous decisions in power engineering with unit-type thermal power plants and advanced, as decisive factors, the techno-economic justification in terms of the stated total costs and operating conditions in the variable part of power-system load curves, the mastering and reliability of thermal power plants in power systems.

The degradation of the traditional cycle of the second region in world power engineering at the initial and present stages of its development is characterized by enormous difficulties in mastering and by unsatisfactory operation of power units, power systems, and power engineering as a whole in the developed countries of the world, for the following reasons:

1. The existence of a many-year loss-making period of operation of unit-type thermal power plants with the traditional cycle of the second region. For many years it has not been possible to achieve the design performance indicators of such units either in economy, or in reliability, or in the number of hours of utilization of installed capacity.

2. Large underproduction of electric energy during the period of mastering supercritical-pressure and super-supercritical-pressure units. The forced production, for this reason, of electric energy at old, uneconomical thermal power plants, and an increase in the specific fuel consumption in power systems during this period of mastering the units.

3. Enormous additional capital investments and expenditures of material resources during the many-year period of unreliable and emergency operation of unit-type thermal power plants.

4. Large losses in power engineering connected with the operation of units not yet mastered, with the development of new, more advanced units, and with their mastering and introduction.

5. A deterioration in the effectiveness of power-system operation as condensing units are developed and well mastered, associated with the incompatibility of unit-type base-load thermal power plants with the conditions of variable operation of power systems (the emergence of the problem of peak capacity, the construction of uneconomical peak power stations, the low effectiveness of the operation of supercritical-pressure and super-supercritical-pressure units in the variable regime of power systems [7]), leading to an increase in the specific fuel consumption in power systems and in the stated calculated costs of producing electric energy in the country as a whole.

The degradation of the traditional cycle of the second region in future power systems, with well-mastered unit-type thermal power plants and their mass introduction, will be

will manifest itself through a further aggravation of the main contradiction of condensing block thermal power plants: the incompatibility of the operation of base-load block units with the conditions and requirements of the development of the power industry of the future, with flattened load curves and the construction of base-load nuclear power plants. The transfer of block thermal power plants into the variable part of electric-power-system load curves (a small number of hours of utilization of the installed capacity of block thermal power plants, construction of peak-load thermal power plants) will lead to a sharp increase in the specific fuel consumption and in the estimated costs of producing electric power in the future electric power systems of the developed countries of the world. The expected number of hours of utilization of the installed capacity of 300 MW condensing blocks in the European part of our country in 1985 will amount to only 1000–1200 hours per year instead of the 7000 hours for which they are being designed at present. The 800 MW coal-fired blocks that are still only being developed in our country will, in 1985, operate with utilization of installed capacity on the order of 5000 hours per year [5]. This degradation of the traditional cycle of the second domain will be expressed in the future as a continuous deterioration in the thermal economy of the power industry of the countries of the world: in a continuous increase in the specific fuel consumption and in the corresponding estimated costs of producing electric power, instead of their reduction, as is currently planned for the development of future power systems—both through the generation of electric power by modern base-load expensive blocks in variable operation with very low economy, and through the construction of special uneconomical maneuvering peak-load and semi-peak thermal power plants of various types and special steam-turbine blocks for variable operation of high capacity and low economy (Fig. 1. Scheme of degradation of the traditional cycle in the power industry of the USA).

Fig. 1. Dynamics of the increase in specific fuel consumption in connection with the degradation of the traditional cycle of the second domain in the power industry of the USA.
A — Record level of minimum fuel consumption in the power industry of the USA. A—B—C — Beginning of the degradation of the traditional cycle of domain II. Increase in specific fuel consumption in the country, reduction of the efficiency of using block thermal power plants with improvement in the reliability and economy of operation of blocks in the base-load mode. C—D — Further degradation of the traditional cycle of domain II in future power systems. D, D′, D″ — Possible situations in the development of the power industry of the future USA according to TPI forecasts in connection with the degradation of the traditional cycle. D — Maximum development of nuclear power plants; considerable capacity of maneuvering thermal power plants of low thermal economy; large share of operation of block thermal power plants in the variable part of the load curves of electric power systems; low or normal capacity reserve in power systems. D″ — Low share of nuclear power plants in power systems; low share of peak-load maneuvering thermal power plants in electric power systems; large capacity reserves; less significant flattening of electric-power-system load curves. A′—E—F—K — Forecast specific fuel consumption in the power industry of the USA from the transition of the power industry to powerful high-economy base-load blocks in future electric power systems of the USA, without allowance for the inevitable degradation of the traditional cycle of domain II. A—B—C — Actual economy of the power industry of the USA from the transition to powerful supercritical-pressure and condensing blocks and their good assimilation, caused by the degradation of the traditional cycle of domain II. BB′ — Increase in actual fuel consumption in the USA in 1967; CC′ — the same in 1969 in comparison with 1963. BE, CF — The same relative to the level forecast from the introduction of block thermal power plants in the USA.

The degradation of the traditional cycle of the second region will also occur because of nonoptimal decisions in the development of unit-based power engineering at the present stage and, in particular, because of the overstatement of the initial steam parameters and \(\eta_t\) of units already implemented and being designed for the next 10–15 years (240 ata, 540°C), especially that part which will above all be forced to operate in a variable regime. The present parameters and thermal economy of high-capacity units are excessive for future power systems in terms of the use of installed capacity and the requirements of variable-regime operation of large units. An enormous number of such regime-incapable units in present-day power engineering may cause significant damage to future power systems, complicate operation and the reliability of their work. It will be necessary to develop special measures in the form of creating a large power reserve, using a significant capacity of maneuverable thermal power plants of low economy, including units of increased regime capability with low thermal economy.

In this respect, the present parameters of units and \(\eta_t\) have reached, for the traditional cycle of the second region, the very highest expedient level in the development of unit-based power engineering, and further development of the traditional cycle, in all probability, will proceed along the path of reducing these already achieved steam parameters in accordance with the conditions of variable-regime operation of unit-based thermal power plants in future power systems. Therefore, forecasting present-day parameters of unit-based power engineering for future power systems will prove nonoptimal, significantly overstated, just as occurred in the development of unit-based thermal power plants in the past, when in the 1950s the USA began introducing inexpedient units at 300–350 ata, 600–650°C and was then forced to proceed to the introduction of units at 240 ata, 540°C.

The degradation of the traditional cycle of the second region will also be expressed in the uncontrollability of the development of future power systems owing to erroneous decisions and forecasting of unit-based thermal power plants at the present stage, the emergence of situations and actual results of technical progress not foreseen at present, the worsening of the operation of future power systems, and especially in the reduction of thermal economy in comparison with the level achieved at the present stage in the USA and of the effectiveness of capital investments in existing and planned units. This unsatisfactory picture of the development of the traditional cycle of the second region, its inability to ensure technical progress in the power engineering of the future, is an objective regularity, a consequence of the properties and contradictions of the traditional cycle, which is already beginning to manifest itself in US power engineering. In US power engineering over the past 7–8 years, for these reasons, there has been a continuous increase in the specific fuel consumption, especially substantial in comparison with the consumption forecast for those years, and a decrease in the effectiveness of capital investments in unit-based thermal power plants over those years (Fig. 1). This is the essence of the degradation of the traditional cycle as a law of development of world power engineering.

Objective and regular, on the other hand, is the discovery of adiabatic phase formation, the emergence and development of the idea of transferring power engineering to adiabatic phase formation as the only presently known possibility for technical progress in modern and especially future power engineering, as an effective means of overcoming the degradation of the traditional cycle of the second region [2, 3, 4, 6].

References

1. Increasing the reliability and economy of power units at SKD. Teploenergetika, 1970, No. 5.

2. S. V. Polozhii. Fundamentals of scientific forecasting in power engineering. Forecasting of steam-turbine units with adiabatic phase separation. TPI Information Bulletin No. 3 on the problem of converting thermal power plants to AF, 1969. State registration No. 70002202, microfilm, Moscow, 1970.

3. S. V. Polozhii. Adiabatic phase separation. TPI Information Bulletin on the problem of converting thermal power plants to AF. Tomsk, 1969. State registration No. 70002200, microfilm, Moscow, 1970.

4. S. V. Polozhii. Review of TPI studies on steam-turbine units with adiabatic phase separation. Questions of converting thermal power plants to adiabatic phase separation. TPI Information Bulletin on the problem of converting thermal power plants to AF. Tomsk, 1970. State registration No. 70013070, microfilm, Moscow, 1970.

5. G. B. Levental, L. S. Popyrin. Optimization of thermal power installations. Moscow, Energiya, 1970.

6. S. V. Polozhii. Once again on the question of applying adiabatic phase separation in steam-turbine units. Izvestiya TPI, vol. 205, 1972.

7. P. S. Neporozhnii. Problems and prospects of scientific and technological progress in thermal power engineering. Teploenergetika, 1973, No. 1.