CURRENT STATE AND PROSPECTS OF SCIENTIFIC RESEARCH ON THE PROBLEM OF ADIABATIC VAPORIZATION

S. V. Polozhii

(Presented by Prof. I. N. Butakov, Doctor of Technical Sciences)

At the Tomsk Polytechnic Institute, the problem of using adiabatic vaporization in power engineering is being developed [1—7], and experimental and theoretical studies of adiabatic vaporization have been carried out [8—14]. This direction in the development of science is of great practical importance in various branches of industry. The latter circumstance requires an analysis of the state and further development of scientific research in this field.

Adiabatic vaporization, without the supply of heat during the process of change of aggregate state, has the following features: 1—the formation of the kinetic energy of the flow in the process of vaporization; 2—atomization of the liquid phase, dispersion of the flow; 3—enormous rates of steam generation and flow dispersion.

These specific properties of adiabatic vaporization make it possible, as studies show, to use this process effectively for practical purposes, and above all in power engineering: in steam-turbine condensing power stations and thermal power plants, in steam-gas and nuclear power installations, and in magnetohydrodynamic installations for utilization of plasma heat. The considerable kinetic energy and high rate of the process are the reason for the application of adiabatic vaporization in rockets of various purposes. This process is convenient for jet devices. Flow dispersion with vaporization in this process is used for drying viscous solutions. The same properties have been proposed for use in atomizing viscous fuels in internal-combustion engines. For the same reason, adiabatic vaporization can be used for the jet propulsion of high-speed vessels on hydrofoils. Along with this, it is necessary to solve a number of questions connected with the manifestation of adiabatic phase transformations in technology: the outflow of heated water, the use of the heat of continuous blowdown at thermal power stations, and the expansion of wet steam in steam turbines. There are a number of other fields in which work is being conducted on the use of the properties of adiabatic vaporization: desalination of seawater for industrial purposes, in the food industry, etc. This, in particular, explains the great interest in the materials of TPI on the study of adiabatic vaporization. Thus, for example, in 1963—64 the research materials of TPI on adiabatic vaporization were requested by such diverse scientific-research organizations as

of our country, such as the Institute of Thermal Power Engineering of the Academy of Sciences of the Ukrainian SSR, the Institute of Technical Thermophysics of the Academy of Sciences of the Ukrainian SSR, the Azerbaijan Institute of Oil and Chemistry, the problem laboratory for the use of seawater in industry, Kharkov Polytechnic Institute, the Kiev Institute of Food Industry, and others.

This review of the practical use of adiabatic vaporization at present and in the future points to the need for broad development of scientific research in this new field, corresponding to the formulation of this problem as an independent scientific direction.

Researchers first encountered the phenomenon of adiabatic vaporization when determining flow rate during the discharge of heated water. Despite the long history and considerable number of studies in this field, this question has in fact not been solved up to the present time [9, 10]. This is explained by the fact that, in both theoretical and experimental studies, attention was not devoted to the study of the process of adiabatic vaporization itself. These researchers attempted to solve this problem by analogy with the discharge of a single-phase liquid. In such experimental investigations the task of studying the physical essence of the process, its specific features and regularities, was extremely limited. The experiments were set up in a highly simplified manner and were not based on a correct theoretical hypothesis. The researchers were left unaware of changes in the parameters of the process, the energy and velocity of the outflowing stream, the place of nucleation of the vapor phase and the structure of the flow, the amount of vapor formed and the factors affecting these processes, etc. Researchers of this question had no conception of this phenomenon as adiabatic vaporization. All this compelled them to proceed by way of assumptions having nothing in common with the actual essence of the process [9, 10].

A similar situation is observed in studies connected with adiabatic condensation, which occurs during the expansion of wet steam in steam turbines [11—13]. The unsatisfactory state of scientific research on moisture losses in steam turbines is now known, despite the exceptional importance of the question, the great scope of the investigations, and their long history. Here, too, no one dealt with the study of the physical essence of adiabatic condensation, the specific conditions under which this process proceeds, or its kinetics under the complex conditions of steam expansion in the flow passage of a turbine; even the term “adiabatic condensation” did not exist, just as the term “adiabatic vaporization” did not. Therefore, in theoretical and experimental studies of moisture losses in steam turbines, the phenomena of adiabatic condensation were not studied. As a result, the methodology of such investigations was not based on elucidating the physical essence of the process and did not provide for identifying the actual factors and causes of losses due to the two-phase state in experimental turbines.

As a result of this state of theoretical and experimental research in this field, the true value of moisture losses in operating steam turbines is presently unknown. All this could be established only on the basis of investigations of these phenomena as adiabatic phase transformations, which showed that in experimental single-stage turbines, in tests involving the transition from superheated to wet steam, there are no conditions for the occurrence of moisture losses. In this case the nucleation and development of the liquid phase in the nozzles of single-stage turbines occurs throughout the entire volume and has a microca-

integral character, with a velocity-uniform flow structure, incapable of causing losses from steam wetness. These theoretical conclusions were not in agreement with the experimental data of investigators of wetness losses, in which a proportional dependence of the magnitude of the losses on the moisture content in the steam was established [11, 12]. The discrepancy of such experimental data on wetness losses with our theoretical conclusions, based on the study of adiabatic phase transformations, cast doubt on the correctness of the contemporary methodology of experimental and theoretical studies of wetness losses and became the reason for a special investigation of this question [11—13]. The real cause of the drop in efficiency in experimental turbines during the transition from superheated to wet steam is the change in the physical and thermodynamic properties of the flow and the off-design operating conditions of a single-stage turbine on wet steam, which were not taken into account in such experimental and theoretical studies.

Such a critique of contemporary studies of wetness losses in steam turbines did not receive objections from investigators in this field (MEI, LPI, BITM, KhPI). These investigators did not address the substance of this important problem [12, 13].

The kinetic energy of adiabatic vaporization is realized with high efficiency in expanding (power-producing) evaporative elements (EE). In the theoretical case, the magnitude of the kinetic energy of the flow corresponds to the heat drop \(\kappa g\) of the saturated liquid under an isoentropic pressure drop and depends on the difference and the interval of the pressure drop [8—10, 14]. According to experimental data, the efficiency of the real process of converting the heat drop into the kinetic energy of the flow during adiabatic vaporization, even at low initial pressures, is close to the efficiency of steam outflow from expanding nozzles [15, 16]. At the same time, the degree of perfection of this process increases as the pressure interval increases. For example, according to our experiments, the energy efficiency of expanding EEs when the pressure of heated water at about one atmosphere is discharged into a vacuum is 0.60—0.70. According to Frenzel’s experimental data [15], at excess pressure the efficiency of expanding EEs is 0.86—0.89. According to LPI experiments [16], when the pressure of saturated water is reduced from 30—40 bar to 1 bar, the efficiency is 0.92—0.93. On the basis of these experimental studies, LPI arrived at the conclusion that there is a high degree of conversion of enthalpy into kinetic energy. This conclusion is fully consistent with our theoretical and experimental studies of this question [8, 9].

For a given interval and magnitude of the pressure drop, the efficiency of obtaining kinetic energy is determined entirely by the geometrical parameters and the type of evaporative elements. Cylindrical, conoidal, and diaphragm EEs, in terms of the degree of perfection of the process, belong to non-power-producing EEs, in which the vaporization process proceeds without a substantial increase in the kinetic energy of the flow [10, 14]. For example, when pressure is discharged at a temperature of 95°C into a vacuum, the outflow velocity from an expanding EE is 187 m/sec, from a cylindrical one 28 m/sec, and from a conoidal one 32 m/sec, with one and the same outflow velocity from these nozzles of cold water of the order of 10 m/sec.

At present, in foreign countries (Italy, the USA, the FRG, etc.) intensive work is being carried out on the use of the energy of adiabatic vaporization to create reactive thrust in rockets (water rockets) [17]. In Italy a patent has been obtained for an invention in which

a formulation has been developed for a special liquid which, upon reacting with water in the rocket’s boiler-tank, raises the temperature of the water to 300°C in 0.3 sec. The velocity of the outflowing stream reaches 470 m/sec, which creates considerable thrust. Such rockets are being developed as accelerators (boosters) for aircraft takeoff or for launching heavy rockets, and also as meteorological rockets for servicing aviation and for communications over short distances.

At TPI, as already mentioned, considerable work has been carried out on the use of adiabatic vaporization in steam-turbine installations. Here it has also been proposed to apply adiabatic vaporization to the ejectors of steam turbines, using for this purpose the blowdown water of boiler units. Replacing steam ejectors by ejectors using the blowdown water of boiler units eliminates, at thermal power stations, the consumption of live or extraction steam for creating vacuum in the condensers of steam turbines and, by an equivalent amount, increases electric-power output and reduces fuel consumption. The use of adiabatic vaporization in steam-turbine installations makes it possible to overcome the principal shortcomings of the modern steam-power cycle [1].

As a result of the contradictions and shortcomings of the modern steam-power cycle, industrial condensing power stations and combined heat-and-power plants, as well as other types of steam-power installations of small capacity, are at a low technical level of development and have no prospects for improving thermal efficiency. This is explained by the fact that, with the modern method of steam generation, an increase in the thermal efficiency of steam-turbine installations is impossible while maintaining the low steam pressure favorable for the effective operation of steam turbines of moderate capacity. In order to keep the relative internal efficiency of steam turbines at a sufficiently high level while increasing the initial steam pressure to superhigh and supercritical values, it is necessary simultaneously to increase the capacity of the steam turbines to hundreds of thousands of kilowatts.

In steam-turbine installations of enormous capacity, which permit an increase in pressure to supercritical values under the condition of preserving turbine efficiency, the possibilities for introducing superhigh steam superheat temperatures, necessary for achieving high thermal economy of such powerful thermal power stations, sharply deteriorate. As a result, steam-turbine installations of superhigh pressures and enormous capacity, in terms of initial temperatures, lag sharply behind gas-turbine installations. The superhigh and supercritical steam pressures required in powerful steam-turbine installations only to increase the thermal efficiency of the cycle are, in all other respects, negative.

Such pressures lead to enormous expenditures of metal, especially costly high-alloy steels, to a sharp increase in the cost of power equipment, to the complication of heat-flow diagrams, to the use of repeated steam reheating and a complex system of steam pipelines, increase the requirements for the quality of water and steam, reduce operating reliability, and so on. The use of such pressures required the organization of major research and the expenditure of material resources on the creation and mastery of supercritical steam pressures. The introduction of supercritical steam pressures at superhigh temperatures in large-capacity unit installations, as foreign practice has shown, has not justified itself. In essence, these colossal efforts and expenditures proved to be a huge industrial experiment, on the basis of which it was practically established that it is inexpedient to increase thermal economy at the expense of supercritical pressures and superhigh temperatures requiring the use of austenitic steels. The fuel saving actually achieved

In such installations, as a result of the use of supercritical pressures with double intermediate superheating to 600–650°C, after three to four years of operation in the United States the efficiency in most cases was far from reaching the calculated value, while the cost of the equipment of such stations was exceptionally high [18, 19]. As a result, in the development of power engineering in capitalist countries there arose a tendency to move away from extremely high steam-superheat temperatures, and the initial temperature in unit thermal power plants under construction and design was reduced from 650–600°C to 540–520°C. The great difficulties encountered in mastering even lower steam parameters in the USSR are well known: 130 bar, 565,565°C and 240 bar, 565,565°C. A comparison of the technical and economic indices of modern state district power stations with superhigh steam parameters with those of thermal power plants of the preceding period—of small capacity and lower parameters, uneconomical and with high specific capital costs—leads to a positive assessment of the development of power engineering along the path of introducing superhigh steam parameters. Owing to the exceptionally high concentration of electric-power production in large unit state district power stations, along with an increase in thermal efficiency, a reduction is achieved in the specific costs of construction and operation of such installations. But if one compares modern high-capacity state district power stations of supercritical pressures with proposed installations of the same capacity and thermal efficiency but with low steam pressures, the regressive significance of developing and introducing modern state district power stations would become obvious.

The use of adiabatic steam generation in steam-turbine installations leads to an optimal type of thermal power plant that eliminates the principal shortcomings and contradictions of modern steam-turbine thermal power plants of both small and large capacity. This determines the exceptional urgency of the problem of using adiabatic steam generation in steam-power installations, and the need for comprehensive development of scientific research to solve this problem. To this end, theoretical and experimental studies on this problem, as well as calculation, design, and construction work, have been conducted for a long time at the CPI; some of the results have already been published [1–14]. Design and calculation studies established the technical and economic indicators of thermal power plants with adiabatic steam generation: efficiency, specific consumption of heat and fuel, steam, metal, and so forth. Variants were considered both for the construction of new thermal power plants with adiabatic steam generation, with different steam parameters, unit and aggregate capacities, types and purposes, and for the expansion and modernization of existing condensing power stations and combined heat-and-power plants. The design of steam-gas and nuclear power plants was also carried out. New turbogenerators with evaporator-generators were designed and developed, as were units based on existing production series of superhigh-pressure turbines—intermediate- and low-pressure cylinders—and low-pressure district-heating turbines. Water-heating boilers of various capacities and steam-superheat temperatures and other equipment for such thermal power plants were developed.

In [1, 2, 4, 5] some data are published from theoretical studies and design developments of steam-power installations with adiabatic steam generation. In industrial thermal power plants, the introduction of adiabatic steam generation will make it possible to increase their thermal efficiency by 30–100% and at the same time sharply reduce the metal consumption and cost of the power equipment of such thermal power plants, as well as increase the capacity of industrial thermal power plants by 30–80%. In this case, the introduction of adiabatic steam generation will be carried out on the basis of inexpensive, well-

of mastered low-pressure turbine equipment, and the construction of water-tube boilers made of carbon steel.

In large-scale power engineering, with heat economy equivalent to that of modern unit-type thermal power stations operating with supercritical steam parameters, the introduction of adiabatic steam generation makes it possible to reduce the cost of boiler units by one and a half to two times, sharply reduce metal consumption—especially of alloy steels—the cost and metal consumption of steam turbines, of the regenerative feedwater-heating system, and of steam pipelines; to increase the production capacities of the power industry, the pace of power-plant construction, etc.

In studies of adiabatic steam generation and of the operating conditions of IG turbines (evaporator-generators), it has been possible to identify the basic regularities and properties of the process of steam and energy generation in evaporating elements and of the flow’s operation on the turbine wheel, which have proved to be such as to ensure efficient and reliable operation of evaporator-generator turbines.

The principal role in ensuring efficient and reliable operation of IG turbines belongs to the evaporating elements, in which the conversion of heat drop into kinetic energy occurs with high efficiency. The magnitude of the heat drop and the outflow velocity of the stream in the evaporating elements determine the single-stage active principle of operation of evaporator-generator turbines (at optimal ratios \(U/C\), 3000 rpm, normal disk diameters, and other favorable conditions), without which reliable and efficient operation of such turbines is impossible. The molecular-dispersed structure of the flow obtained in the evaporating elements, in turn, eliminates the possibility of erosion of the working blades and moisture losses in such single-stage IG turbines. The amount of steam formed in the evaporating elements, the volumetric flow rates of low-pressure steam, and the physical and thermodynamic properties of the steam are also favorable for its use on the working blades of the turbine wheel. These conclusions regarding the role of the evaporating elements in ensuring reliable and efficient operation of IG turbines have been confirmed experimentally [3, 6, 15, 16, 20]. In steam-turbine installations with adiabatic steam generation, the choice of a low pressure in the evaporator-generator has proved successful; it ensures reliable and efficient operation of IG turbines, a high value of the relative internal efficiency of steam turbines even of small capacity, and the thermal efficiency of the cycle even at low steam-superheat temperatures; it improves the operating conditions and efficiency of the boiler units of such installations. Low steam pressure, combined with the high heat economy of steam-power plants with adiabatic steam generation, leads to a positive techno-economic effect, to a sharp reduction in the consumption of metal and funds, in initial and current investments; it simplifies the thermal schemes of thermal power stations, the main and auxiliary equipment, reduces the requirements for water and steam, etc.

The erosion-free and efficient operation of a two-phase flow on the working blades of evaporator-generator turbines is at present substantiated only theoretically, on the basis of experimental studies of adiabatic steam generation, of evaporating elements, and of the operation of models of laboratory vacuum IG turbines.

A theoretical study of the motion of a two-phase flow at the outlet from the evaporating elements and in the curvilinear channels of the working wheel made it possible to establish the critical size of liquid droplets, exceeding which leads to a change in the trajectories and velocities of the liquid particles, as compared with the steam particles, and to the occurrence of

losses from moisture and erosion of the rotor blades. This critical droplet size for the operating conditions of GT turbines proved to be hundreds of times larger than the maximum sizes of liquid droplets in the flow of evaporator-generator turbines. These theoretical conclusions have a high degree of reliability, ensured by the general state of scientific research on the motion of a two-phase flow in the flow path of gas turbines, by experimental investigations, and by the operating experience of solid-fuel gas turbines [21, 22], according to which ash particles of several microns have, in the turbine flow path, the velocities and trajectories of the gas flow, ruling out loss and erosion due to the two-phase state of the flow. This is also confirmed by our studies of actual losses in experimental single-disk steam turbines during the transition from superheated to wet steam [11, 12], and by experimental studies of flow dispersion during adiabatic steam formation. Theoretical and experimental studies of the motion of wet steam itself in recent years [23] and of the condensed phase in interblade channels [22] confirm our conclusions concerning the influence of the critical size—the dispersion of a two-phase flow—on the loss and erosion due to the two-phase state of the flow.

As a result of this complex of theoretical and experimental investigations, calculation and design work carried out at TPI, it proved possible to bring to a successful close the first stage of work on substantiating the progressive significance of the use of adiabatic steam formation in thermal power engineering and to raise the question of further development and introduction of adiabatic steam formation into steam-turbine installations. To this end, TPI concluded a contract research project with one of the power systems of Siberia on the use of adiabatic steam formation at a thermal power plant; it was also proposed to the State Committee for Power Engineering and Electrification of the USSR that a contract project be concluded on the development and introduction of adiabatic steam formation in steam-turbine installations.

The development of scientific research on the problem of using adiabatic steam formation in steam-turbine installations proceeded with great difficulties; completion of the work was delayed for many years, and it proved impossible to set up experimental investigations of GT turbines in the range and under the conditions of their use in power engineering. TPI’s attempts to organize the further development and introduction of adiabatic steam formation in steam-turbine installations by carrying out contract work on this problem with the State Committee for Power Engineering and Electrification of the USSR in 1965 proved fruitless.

These difficulties were caused by the negative position of a number of leading scientists and scientific-research organizations in Moscow concerned with the development of modern power engineering and with the development and introduction of superhigh and supercritical steam parameters. This negative position of a group of scientists was determined by both objective and subjective factors and proved difficult to overcome.

The objective factors include the novelty of these investigations and the existence of experimental and theoretical studies of the outflow of heated liquid, in which adiabatic steam formation appears, and of erosion and losses from moisture in steam turbines, in which adiabatic condensation appears. In both areas, scientific investigations were carried out without studying adiabatic phase transformations, without a correct conception of the physical essence of these processes and of their specific features and regularities—

adiabatic vaporization and adiabatic condensation [8–14], and for this reason were not only unable to solve these problems at the proper level, but also misoriented the scientific community as to the true nature of adiabatic phase transformations. Such studies of the outflow of heated water, which have already been mentioned, led to erroneous conclusions and notions about the low kinetic energy of the flow, the low degree of perfection, and the great metastability of the process in the evaporating elements of IG turbines, and about the impossibility of implementation and the unsuitability of adiabatic vaporization for steam-turbine installations (TsKTI, ENIN).

An even more serious obstacle is posed by theoretical and experimental studies of moisture losses in experimental steam turbines, on the basis of which losses in operating turbines are estimated. Here, too, it was necessary to reveal the erroneousness of the methodology of such studies, and the unsuitability of such experimental and theoretical data for a correct assessment of moisture losses in steam turbines [11, 12], and all the more so in IG turbines.

The lack of awareness of the scientific and technical community about the phenomena of adiabatic vaporization, its basic properties and regularities is another objective factor. This factor was one of the reasons for the uncritical transfer of moisture losses in steam turbines to IG turbines, for a mechanical approach to this question, without analysis of the conditions, the physical essence of the process, and the operating principle of the turbines. By thus identifying the conditions and operation of steam turbines with IG turbines, such scholars deny the possibility of creating efficient and reliable turbines for evaporator-generators and of solving the problem of using adiabatic vaporization in steam-turbine installations (TsKTI, ENIN, MEI). In the review by MEI, for example, the denial of the efficient and reliable operation of IG turbines is built on an analogy with the operation of feed pumps and marine propellers. Only the absence of an adequate understanding of adiabatic vaporization and the operating conditions of IG turbines can explain the appearance of such a review. The denial of the economic advantages of steam-turbine installations with adiabatic vaporization—reduction in metal consumption, in the cost of power equipment, etc.—is made by such scholars on the basis of assumptions.

As an example of such unscientific, unsubstantiated denials of the problem of using adiabatic vaporization in steam-turbine installations, one may cite the ENIN conclusion on the proposal of TPI concerning the development and introduction of adiabatic vaporization into thermal power engineering.

Against the factual materials of theoretical and experimental studies, and against design and engineering developments of power equipment and thermal power plants with adiabatic vaporization, the authors of the ENIN conclusion (Doctor of Technical Sciences G. E. Kholodovskii and engineer I. I. Abdrashitov) oppose personal doubts and unsubstantiated assertions, such as: “The operation of the main element of the IG raises doubts”... “Hydraulic shocks, erosion, and wear of the blades, with all the consequences arising therefrom, are inevitable”..., “the reduction of metal consumption in the IG installation raises doubts.” Such arguments cannot serve as scientific proof capable of refuting the research materials in this new field. Moreover, the authors of the conclusion allow a gross distortion of the research materials of article [1] in order to substantiate the inapplicability of adiabatic vaporization in high-power steam-turbine installations. In [1] a comparison is given of the thermal efficiencies of theoretical cycles

with IG and Rankine cycles for different steam parameters and, in particular, the value of the thermal efficiency of the Rankine cycle at 180 bar, 550/535°C and of the IG cycle at 80 bar, 550°C, whose values are equal. In order to refute this equality of the thermal efficiencies, the authors of the conclusion carried out a peculiar verification of these data. Into the calculations of the theoretical Rankine cycles 180, 550/535° and IG 80, 550°C they introduced the relative internal efficiencies of the IG and steam turbines in an arbitrary interpretation. For the IG turbines they assumed an efficiency equal to 0.7, and for the steam turbines of the IG and Rankine cycles—0.9, considering also the efficiency of the super-high-pressure cylinder to be equal to 0.9, which in practice can never occur; while for low-power turbines the internal relative efficiency at super-high pressure (a super-high-pressure cylinder) may even have a negative value. With such an arbitrary and, moreover, incorrect substitution of turbine efficiencies in the calculation of theoretical cycles, in which losses in power equipment are not taken into account, the authors of the conclusion distorted the calculated data in [1], obtaining the thermal efficiency of the Rankine cycle at 180 bar, 550/535°C as 3% higher than the efficiency of the IG cycle at 80 bar, 550°C; they declared the calculations in [1] to be erroneous and came to the conclusion that adiabatic vaporization is inapplicable in thermal power plants. On the basis of such a conclusion, the ENIN State Committee for Power Engineering and Electrification of the USSR refused to conclude an economic contract for the development and introduction of adiabatic vaporization in steam-turbine installations.

The discovery of adiabatic vaporization, its objective essence, is in contradiction with modern scientific investigations of processes associated with adiabatic phase formation. The use of adiabatic vaporization in steam-turbine installations comes into conflict with the present state and development of thermal power engineering, reveals the shortcomings of existing steam-turbine installations, and requires their elimination.

The decision of the meeting at ENIN on this problem on November 21, 1965, was directed against such a possibility, against scientific research and the introduction of adiabatic vaporization into the power engineering of our country, by way of non-recognition of the factual materials of investigations of TPI, unfounded denials, abstract conclusions, and even erroneous assertions. This explains why the negative decision of the meeting at ENIN was not supported by the thermal-power engineers of TPI. This decision of the meeting at ENIN is also inconsistent with the numerous conclusions and resolutions of scientific-technical conferences and meetings of TPI, scientific sessions of higher educational institutions of Western Siberia, scientific seminars of thermal-power engineers of higher educational institutions and industry of Tomsk, the All-Union meeting on the construction of large unit condensing power stations in Siberia (Kemerovo), the Scientific-Technical Council of the Ministry of Higher and Secondary Specialized Education of the RSFSR, the Council of the Thermal-Power Faculty of TPI, special discussions, opinions of individual scientists, and reviews of published works on this problem. Opponents of these investigations, as well as authors and researchers who were criticized in the published works on the problem under consideration, did not appear in print with their objections, did not express their negative attitude toward the results of investigations at TPI, and did not take part in the press in discussions and debates on the questions under consideration.

The meeting at ENIN in fact recognized the high value of the thermal economy of STU with AV, in absolute magnitude 32–34%. This value of the STU with AV exceeds the thermal economy by 30–100%

... the capacity of industrial TPPs in our country, whose efficiency lies within the range of 15–25%.

The introduction of STUs with AV into industrial TPPs will make it possible to increase their thermal economy by 30–100%, to reduce severalfold the specific consumption of metal and the cost of power equipment for industrial TPPs, and to increase their capacity by one and a half to two times. If one takes into account that industrial TPPs currently consume more than 33% of the fuel burned at the country’s power stations, generate about 20% of all electric power, and account for 12% of all TPPs in installed capacity, while CHPPs account for 40%, then one can imagine the enormous importance that solving this problem acquires for the national economy. The introduction of adiabatic vaporization into industrial thermal power engineering will be tantamount to a technical revolution in this branch of power engineering.

It is also necessary to note the unworthy methods used by opponents of this problem in polemics concerning the essence of this work. For example, the Central Boiler-Turbine Institute extends the calculated data on an increase in the efficiency of industrial TPPs by 30–100% upon introduction of STUs with AV to powerful thermal power stations with super-high steam pressure, and ascribes such absurd data to the author of the work. The Central Boiler-Turbine Institute had already earlier committed a gross error in its assessment of STUs with AV, denying the possibility of effective operation of the evaporative elements of hydraulic turbines on the basis of experimental data on the discharge of heated water from orifices and cylindrical nozzles available in the literature, in which the conversion of heat drop into kinetic energy of the flow cannot be effected. The untenability of such a conclusion by the Central Boiler-Turbine Institute is now well known from the experimental data of other authors [15, 16], which have already been discussed.

This brief review of the current state of research on adiabatic vaporization and its practical use, of the scientific content of critical remarks and reviews concerning this problem, and of the unsatisfactory formulation of experimental and theoretical studies of moisture losses in steam turbines, as well as of the outflow of heated liquids, shows the need for further development and proper organization of scientific research in this field, for coordination of these investigations, and for the holding of scientific and technical meetings and conferences on the problem of adiabatic vaporization as a whole.

An important task in further scientific research on this problem is the creation of a fundamental theory of adiabatic phase transformations, the disclosure of the molecular nature of the basic law of adiabatic vaporization [13]. On the basis of such a theory it would seem possible to solve more effectively the problems of the practical use of adiabatic vaporization in various branches of technology.

An important result of the investigations of the Department of Thermal Power Installations of TPI is the discovery of adiabatic vaporization as an objectively existing process of nature, knowledge of whose properties and regularities is of great importance for practice.

In nature there is a considerable number of places where adiabatic vaporization proceeds visibly, and almost everywhere there is the possibility of obtaining this process. The question concerns those enormous reserves of heated underground waters in nature which have already been explored, and those which await discovery. In Siberia, oceans of such highly compressed heated underground waters have been discovered. These are the natural reservoirs, the “water-heating boilers”—sources of adiabatic vaporization in nature.

In places where the earth’s strata are naturally ruptured, adiabatic vaporization proceeds visibly in the form of geysers—the outflow of underground heated water with the formation of steam, kinetic energy, and a dispersed stream. This process has been occurring in nature for millions of years, and only at the present time has it been discovered as adiabatic vaporization; its features and properties have been investigated, its regularities studied, and paths have been outlined for the broad use of adiabatic vaporization in power engineering and other branches of technology.

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