Condensation Model Research Articles

Performance analysis of two condenser models used for solar energy-assisted water distillation

Performance analysis of two condenser models used for solar energy-assisted water distillation

Top–Bottom Condensation Model: Symmetries and Spectrum of the Induced 2HDM

Here, we use the Schwinger–DeWitt approach to address the four-fermion composite Higgs effective model proposed by Miransky, Tanabashi and Yamawaki (MTY). The surprising benefit of such an approach is that it is possible to ascribe to a SM-type Higgs a quark–antiquark structure of predominantly a b¯b nature with a small t¯t admixture, which in turn yields a Higgs mass compatible with the observed value of 125 GeV. We discuss this result in a detailed and pedagogical way, as it goes against the common belief that this model and akin composite descriptions should predict a Higgs mass-of-order of twice the top quark mass, contrary to empirical evidence. A further aspect of this approach is that it highlights the link of the SU(2)L×U(1)R symmetric four-fermion MTY model interactions of the heavy quark family to a specific two-Higgs-doublet model (2HDM), and the necessity to go beyond the one Higgs doublet to obtain the empirical Higgs mass within composite models. By appropriately fixing the symmetry-defining interaction parameters, we show that the resulting CP-preserving spectrum harbors the following collective states at the electroweak scale ΛEW=246 GeV: a light scalar to which the standard Higgs is associated; a heavier neutral state preconized as the Nambu partner of the standard Higgs within the Nambu sum rule; the expected triplet of Goldstone bosons associated with the longitudinal polarizations of the electroweak massive bosons; and a neutral pseudoscalar state that in the limit of a global U(1)A symmetry would be a Goldstone mode. The anomalous breaking of this axial symmetry is a subleading effect in a large Nc counting scheme, and we discuss how it modifies the leading-order Nambu sum rule result and its relevance for the qualitative description of the spectrum.

Numerical Study of a Cooling System Using Phase Change of a Refrigerant in a Thermosyphon

With the increasing trend toward the miniaturization of electronic devices, the issue of heat dissipation becomes essential. The use of phase changes in a two-phase closed thermosyphon (TPCT) enables a significant reduction in the heat generated even at high temperatures. In this paper, we propose a modification of the evaporation–condensation model implemented in ANSYS Fluent. The modification was to manipulate the value of the mass transfer time relaxation parameter for evaporation and condensation. The developed model in the form of a UDF script allowed the introduction of additional source equations, and the obtained solution is compared with the results available in the literature. The variable value of the mass transfer time relaxation parameter during condensation rc depending on the density of the liquid and vapour phase was taken into account in the calculations. However, compared to previous numerical studies, more accurate modelling of the phase change phenomenon of the medium in the thermosyphon was possible by adopting a mass transfer time relaxation parameter during evaporation re = 1. The assumption of ten-fold higher values resulted in overestimated temperature values in all sections of the thermosyphon. Hence, the coefficient re should be selected individually depending on the case under study. A too large value may cause difficulties in obtaining the convergence of solutions, which, in the case of numerical grids with many elements (especially three-dimensional), significantly increases the computation time.

The relationship of CH, CB, and CR chondrites: Constraints from trace elements and Fe-Ni isotope systematics in metal

Due to similarities in chemical composition and common Cr, Ti, N and O isotope trends, the metal-rich CR, CH and CB chondrites, often referred to as CR clan chondrites, are thought to be related to each other. This study aims to shed light on this relationship by the investigation of Fe and Ni isotope and trace element compositions of metal grains from CR and CH chondrites, in order to compare the results with previously reported data from CB chondrite metal. In situ trace element and Fe and Ni isotope analyses were conducted by femtosecond-laser ablation-(multicollector-)inductively coupled plasma-mass spectrometry (fs-LA-(MC-)ICP-MS). Furthermore, bulk CB metal and silicate separates were analyzed by solution MC-ICP-MS.Chemical compositions of metal grains in metal-rich chondrites are depleted in moderately volatile siderophile elements relative to the solar values with the exception of Pd. Such element abundance patterns are consistent with models of incomplete condensation from a gas with solar composition. Both, zoned and unzoned metal grains from CH and CB chondrites display very similar Fe and Ni isotopes compositions, indicating they likely formed within the same event, during non-equilibrium fractional condensation from an impact-induced vapor plume. This scenario is also supported by non-equilibrium Fe isotope signatures between bulk CB metal and silicate. Zoned metal grains likely formed in the fast-cooling outer shell region of the plume and are dominated by kinetic fractionation, resulting in isotopically light cores, while unzoned metal grains condensed under nearly equilibrium conditions, likely in the slow-cooling interior of the plume. Variability in Fe and Ni isotope compositions among different unzoned grains may be explained by (1) a kinetic component during their condensation and/or (2) evaporation and condensation-driven reservoir effects in the plume, which resulted in light and heavy isotope signatures, respectively. Textural differences between CH and CBb are most pronounced in the mean grain size, which may be attributed to grain-size sorting. Such a process could also explain the lack of zoned metals in CBa chondrites, as zoned metal grains in CBb and CH chondrites are by more than a magnitude smaller than the mean metal grain size of CBa chondrites. In CR chondrites, metal within chondrules likely formed by fractional condensation from a solar type gas followed by subsequent melting leading to equilibration with chondrule silicates. Larger isolated metal grains from the matrix are less processed, and apparently escaped silicate equilibration. Those metal grains are indistinguishable from unzoned grains in CH and CB chondrites in trace elements and Fe and Ni isotopic compositions albeit with a slightly narrower compositional range. Based on these findings we conclude that metal precursors in CR chondrites are strongly related to unzoned metal in CH, and CB chondrites and possibly share a common origin. This metal component would be smallest in CR chondrites, larger in CH and dominant in CB chondrites which is also consistent with age constraints and isotopic anomalies observed in CR clan chondrites.

Modeling of annular and intermittent flow condensation in micro- and mini- channels with experimental validation

Mechanistic models for predicting condensation heat transfer in the annular and intermittent flow regimes are presented and compared with data for different working fluids (R134a and R245fa) over a range of mass fluxes, saturation temperatures (30 ≤ Tsat ≤ 50 °C), saturation-to-wall temperature differences (1.5 < ΔT < 2.5 K), and channel geometries. The annular flow model is based on a laminar assumption and is applicable to arbitrarily shaped micro- or minichannels. Model predictions are validated using experiments focusing on low mass fluxes (G ≤ 100 kg m−2 s−1), for which there are few analytical models or experimental data. The intermittent model developed here is also validated based on similar experiments. The annular model is found to be applicable for G ≤ 100 kg m−2 s−1, Reδ < 61 (square), and Reδ < 125 (circular), while the intermittent model is applicable for G ≤ 150 kg m−2 s−1 and 78 < Reδ < 365.

Atomic-scale structure and non-stoichiometry of meteoritic hibonite: A transmission electron microscope study

Abstract Hibonite (CaAl12O19) is a common refractory mineral in Ca-Al-rich inclusions (CAIs) in primitive meteorites. Transmission electron microscope (TEM) studies have identified enigmatic planar defects in different occurrences of hibonite in the Allende meteorite that give rise to strong streaking along c* in electron diffraction patterns. Atomic resolution high-angle annular dark-field (HAADF) imaging and energy-dispersive X-ray (EDX) analyses were used to determine the nature and origin of these planar features. HAADF images of hibonite grains reveal lamellar intergrowths of common 1.6 nm spacing, and less commonly 2.0 and 2.5 nm spacings, interspersed in stoichiometric hibonite showing 1.1 nm (002) spacing. Stoichiometric hibonite consists of alternating Ca-containing (“R”) and spinel-structured (“S”) blocks stacked in a sequence RS. In contrast, the 1.6 nm layers result from a doubled S block such that the stacking sequence is RSS, while in the widest defect observed, the stacking sequence is RSSSS. These intergrowths are epitaxial and have coherent, low-strain boundaries with the host hibonite Meteoritic hibonite shows common Ti and Mg substitution for Al in its structure. Atomic-resolution EDX maps of hibonite grains in the Allende CAI confirm the preferred site occupancy of Mg on tetragonal M3 sites in S blocks and of Ti on trigonal bipyramidal M2 and octahedral M4 sites in R blocks. Mg is highly concentrated, but Ti is absent in the planar defects where wider S blocks show Al-rich compositions compared to stoichiometric MgAl2O4 spinel. Therefore, Mg likely played the major role in the formation and metastability of planar defects in hibonite. Electron energy loss spectroscopy data from the Ti L2,3 edge show the presence of mixed Ti oxidation states with ~15–20% of Ti as Ti3+ in hibonite, suggesting a direct substitution of Ti3+ ↔ Al3+ in hibonite. The remaining ~80–85% of Ti is present as Ti4+ and corresponding EDX analyses are consistent with the well-known coupled substitution 2Al3+ ↔ Ti4+ + Mg2+ being the major mechanism for Ti and Mg substitution in hibonite. The formation of planar defects in hibonite occurred during high-temperature nebular condensation or melting/crystallization processes. The occurrence of non-stoichiometric hibonite in the Allende CAI deviates from the mineral formation sequence predicted from equilibrium condensation models. Overall, our atomic resolution TEM observations signify non-equilibrium, kinetic-controlled crystal growth during the high-temperature formation of refractory solids in the early solar nebula.

Experimental research on double-hole steam condensation effects and models under different diameters and pitch to diameter ratios conditions

The multi-hole steam Direct Contact Condensation (DCC) is of high efficiency in mass and heat transfer, which has been widely used in the engineering application, especially the advanced nuclear reactor power plant passive safety system. Most of the researches concerned on the single-hole steam DCC characteristics, whereas the multi-hole steam DCC heat transfer effects are influenced by a variety of mutual factors, and the micro mechanisms and models of which are still not very clear yet. In the present work, the double-hole steam condensation effects and models under different spraying diameters and pitch to diameter ratios (P/de) conditions are investigated based on the scaled IRWST & ADS experimental facility. The key parameters including the steam plumes, temperature distributions, penetration length, and heat transfer coefficients, etc. are analyzed. The experimental results show that both the P/de and de can impact the overall condensation behavior and the corresponding penetration length with variation range from -40% to 60% compared to the single-hole condensation cases, further influencing the double-hole steam DCC heat transfer effects. The revised double-hole steam condensation analytical models are proposed to depict the key condensation characteristics. Based on theoretical model and experimental results, the HTC calculation methods are developed to quantitatively estimate the double-hole condensation effects in the range of approximate 0.4-2.8MW/m2°C, which is in similar magnitude with the single-hole theoretical model. However, in overall, the double-hole HTC values are lower than the single-hole cases under the specific mutual influences between the adjacent plumes including overlapping, coalescences, and possible deflection with angles. The present theoretical and experimental work provide important references for the engineering multi-hole spargers design and modification.

Fault diagnosis method based on multi‐source information fusion for weak interturn short circuit in synchronous condensers

The interturn short circuit fault in rotor windings is a common fault in a synchronous condenser. Aiming at the early faults that are difficult to detect, the theory of multi-source information fusion is applied herein for the identification of short circuit faults in the rotor windings of a synchronous condenser. Firstly, a field-circuit-network coupling model of a synchronous condenser for high-voltage direct current (HVDC) transmission was constructed using SIMULINK/ANSYS. The air gap magnetic flux density of the interturn short circuit regulator with a rotor winding was obtained, via co-simulation, before and after the commutation failure in the HVDC inverter. Further, three-dimensional models of the stator and rotor of the synchronous condenser were established using ANSYS/Workbench; the stator and rotor vibration responses of the synchronous condenser were monitored before and after the system commutation failure. Secondly, three types of evidence bodies were obtained based on the Dempster–Shafer evidence theory. The results show that the confidence level of the evidence body of each faulted component of the synchronous condenser increases, and the accuracy of fault recognition also increases upon system commutation failure. Finally, a three-pair-pole synchronous motor (MJF-30-6) was used to simulate the rated and overexcited operations of the synchronous condenser for experimental verification of the feasibility of the proposed method. This method provides a reference for the identification of weak interturn short circuit faults in synchronous condensers.

Modeling of self-excited oscillation of non-equilibrium condensation in transonic moist air flow

Atmospheric air is a popular working fluid in gas power plants and turbomachinery which always contains water vapor. The vapor condensation occurs in transonic flow when the temperature drops below dew point during the accelerating expansion and affects the performance of equipment and safety. The unsteady condensation model based on nucleation and droplet growth model, and the Shear Stress Transport (SST) viscous turbulence model for moist air condensing in transonic flows was proposed. The prediction accuracy of steady and unsteady condensing flows was validated by experimental data and theory. The unsteady frequency and fluctuation intensity of pressures for symmetric and asymmetric condensing oscillation modes were discussed. A new formula (f0 = 1.992Φ01.539ws0.3853) of dimensional frequency related with inlet relative humidity and saturated vapor mass fraction was obtained. Then, periodic mass flux, pressure loss and droplet mass generation rate distributions at different carrier gas pressure were analyzed. The pressure loss coefficient represents the energy loss. As the carrier gas pressure increases, the mass flow rate increases, but the energy of condensation-induced shock decreases. Combined with the analysis of the distribution of liquid mass fraction, it is also found that Mach number and pressure fluctuation are induced by condensation wave due to heat release. Finally, the velocity phase diagrams and heat addition of per unit volume at different oscillation modes were assessed. It reveals the maximum heat addition amounts of per unit volume for three symmetric modes are 1.28 × 103, 1.48 × 103 and 1.54 × 103 MW m−3 along the increase of humidity.

Improvement of Condensation Model With the Presence of Non-Condensable Gas for Thermal-Hydraulic Analysis in Containment

Steam condensation plays a key role in prediction of the pressure behavior and hydrogen distribution in the containment during a hypothetical loss-of-coolant accident or a severe accident in a light water nuclear reactor. The objective of this study is to evaluate and improve the condensation model in GASFLOW code. Reynolds analogy coupled with wall function and Chilton-Colburn empirical analogy is used to model heat and mass transfer in GASFLOW, which has requirements for dimensional distance of the first cell near the wall and some deficiencies in description of heat and mass transfer process in the stagnant zone. Based on the evaluation of original condensation, the results shows good agreement with COPAIN experiment cases where the mass fraction of air ranges from 76.7 to 86.4%. However, with the changes in geometry of the facility and the presence of helium, the original model has a large deviation in the prediction of pressure, temperature and gas distribution compared with MISTRA ISP47 (OECD International Standard Problem No. 47) experiment data. This work proposes a modified condensation model which uses McAdams correlation and Schlichting correlation with a weight factor to calculate natural, forced, or mixed convection heat transfer coefficient, and adopts Chilton-Colburn empirical analogy to model mass transfer. The modified model has no requirement for the dimensionless distance near the wall in heat and mass transfer calculation and improves the prediction performance of heat transfer in stagnant zone. The prediction result of the modified model shows good agreements with MISTRA ISP47 problem, and the error of it compared with COPAIN experiment data is within 25% which is the same as that predicted by the original model.

An Experimental Investigation of Water Vapor Condensation from Biofuel Flue Gas in a Model of Condenser, (1) Base Case: Local Heat Transfer without Water Injection

Waste heat recovery from flue gas based on water vapor condensation is an important issue as the waste heat recovery significantly increases the efficiency of the thermal power units. General principles for designing of this type of heat exchangers are known rather well; however, investigations of the local characteristics necessary for the optimization of those heat exchangers are very limited. Investigations of water vapor condensation from biofuel flue gas in the model of a vertical condensing heat exchanger were performed without and with water injection into a calorimetric tube. During the base-case investigations, no water was injected into the calorimetric tube. The results showed that the humidity and the temperature of inlet flue gas have a significant effect on the local and average heat transfer. For some regimes, the initial part of the condensing heat exchanger was not effective in terms of heat transfer because there the flue gas was cooled by convection until its temperature reached the dew point temperature. The results also showed that, at higher Reynolds numbers, there was an increase in the length of the convection prevailing region. After that region, a sudden increase was observed in heat transfer due to water vapor condensation.

Development of a numerical model of surgical smoke during laparoscopy

An accurate understanding of laparoscopic surgical smoke behaviour is essential to enhance the healthcare of patient and operating room staff and to achieve better optical clarity for the surgeon. This work develops a numerical model of surgical smoke behaviour during laparoscopy. A computational fluid dynamics model was created for a rectangular chamber geometry. A “large eddy simulation” (LES) technique was used to solve transport equations, electrosurgery was modelled using a heat-flux boundary condition, and condensation and evaporation models were employed.An experimental study was undertaken to provide the unknown parameters such as surgical smoke generation rate, water evaporation rate, and heat flux at the electrosurgery site in the numerical simulation. The experimental apparatus was composed of a rectangular chamber with two ports; one used for monopolar electrosurgery, and the other for inlet flow. Condensed water on the chamber inner surface, evacuated water vapour and particulate matter, as well as temperature and relative humidity at different locations within the model, were measured.The experiments showed that surgical smoke generated during laparoscopy is composed of 65% water vapour, 11% particulate matter, and 24% volatile matter by mass. It was measured that particulate matter and water vapour were generated at a rate of 1.9 (±0.3) mg/s and 11.7 (±0.6) mg/s (mean ± SD, n = 8), respectively. The numerical model predicted that approximately 31% - 35% of the generated smoke was evacuated from the outlet port as a relatively high speed flow and the remainder was accumulated close to the upper surface due to buoyancy. The CFD model can be used as a predictive tool to investigate the exposure of operating room staff to surgical smoke, particulate matter deposition on the peritoneum surface and tissue desiccation during electrosurgical procedures.

Effect of layer-by-layer assembled carbon nanotube coatings on dropwise condensation heat transfer associated with non-condensable gas effect

The purpose of this study is to investigate the effect of layer-by-layer (LbL) assembled carbon nanotube (CNT) coatings on dropwise condensation heat transfer under steam–air mixture conditions. To promote dropwise condensation, an additional hydrophobic coating was added to the LbL-assembled CNT coatings, which resulted in a 16% enhanced condensation heat transfer coefficient (HTC) compared to that of the bare surface under saturated steam conditions. Despite the existence of the nanostructures on the CNT-layered surface, the larger droplet size was observed from the high-speed images than that of the bare surface due to flooding condensation phenomenon. Considering that the HTC was enhanced without smaller droplet size, it is evident that this enhancement was mainly attributed to the reduced constriction resistance driven by the high thermal conductivity of the CNT layers. A new HTC model for dropwise condensation incorporating constriction resistance was developed to better predict the measured condensation HTC. Although the enhancement of the condensation HTC on the LbL-assembled CNT coatings was diminished with the air mass fraction, this work reports a new perspective to enhance the dropwise condensation heat transfer performance by controlling the constriction resistance using a highly thermally conductive coating.

Implementation of a new empirical model of steam condensation for the passive containment cooling system into MARS-KS code: Application to containment transient analysis

For the Korean design of the PCCS (passive containment cooling system) in an innovative PWR, the overall thermal resistance around a condenser tube is dominated by the heat transfer coefficient of steam condensation on the exterior surface. It has been reported, however, that the calculated heat transfer coefficients by thermal-hydraulic system codes were much lower than measured data in separate effect tests. In this study, a new empirical model of steam condensation in the presence of a noncondensable gas was implemented into the MARS-KS 1.4 code to replace the conventional Colburn-Hougen model. The selected correlation had been developed from condensation test data obtained at the JERICHO (JNU Experimental Rig for Investigation of Condensation Heat transfer On tube) facility, and considered the effect of the Grashof number for naturally circulating gas mixture and the curvature of the condenser tube. The modified MARS-KS code was applied to simulate the transient response of the containment equipped with the PCCS to the large-break loss-of-coolant accident. The heat removal performances of the PCCS and corresponding evolution of the containment pressure were compared to those calculated via the original model. Various thermal-hydraulic parameters associated with the natural circulation operation through the heat transport circuit were also investigated.

Two-fluid model of rf current condensation in magnetic islands

The stabilization of tearing modes with rf waves is subject to a nonlinear effect, termed rf current condensation, that has the potential to greatly enhance and localize current driven within magnetic islands. Here we extend previous investigations of this effect with a two fluid model that captures the balance of diffusive and thermal equilibration processes within the island. We show that the effective power and resulting strength of the condensation effect can be greatly enhanced by avoiding collisional heat loss to the ions. The relative impact of collisions on the overall power balance within the island depends on the ratio of the characteristic diffusion timescale and the electron–ion equilibration time, rather than the latter alone. Although relative heat loss to ions increases with island size, the heating efficiency does as well. In particular, we show that the latter safely dominates for large deposition profiles, as is typically the case for lower hybrid current drive. This supports the possibility of passive stabilization of neoclassical tearing modes without the precise aiming of the rf waves required for electron cyclotron current drive stabilization.

A Unified Model of Solar Prominence Formation

Abstract Several mechanisms have been proposed to account for the formation of solar prominences or filaments, among which direct injection and evaporation–condensation models are the two most popular ones. In the direct injection model, cold plasma is ejected from the chromosphere into the corona along magnetic field lines; in the evaporation–condensation model, the cold chromospheric plasma is heated to over a million degrees and is evaporated into the corona, where the accumulated plasma finally reaches thermal instability or nonequilibrium so as to condensate to cold prominences. In this paper, we try to unify the two mechanisms: The essence of filament formation is the localized heating in the chromosphere. If the heating happens in the lower chromosphere, the enhanced gas pressure pushes the cold plasma in the upper chromosphere to move up to the corona, such a process is manifested as the direct injection model. If the heating happens in the upper chromosphere, the local plasma is heated to 1–2 million degrees, and is evaporated into the corona. Later, the plasma condensates to form a prominence. Such a process is manifested as the evaporation–condensation model. With radiative hydrodynamic simulations we confirmed that the two widely accepted formation mechanisms of solar prominences can really be unified in such a single framework. A particular case is also found where both injection and evaporation–condensation processes occur together.

Analysis of condensation and secondary flows at three-way junctions using optical visualization techniques and computational fluid dynamics

Three-way junctions are employed in almost all piping systems, whenever two streams need to be merged into one duct. In some applications, the mixing between streams plays an important role for determining the performance of downstream elements. The situation is particularly interesting for low pressure Exhaust Gas Recirculation (EGR) junctions featured in piston engines, where warm humid exhaust gases meet cold fresh air, since the mixing of both streams can produce water condensation. This condensation deteriorates the integrity and performance of the adjacent compressor wheel. This work explores the aforementioned flow configuration in a three-way junction by means of a novel gas test bench that allows the characterization of the transversal section at the junction outlet, and 3D Computer Fluid Dynamics (CFD) simulations embedded with a previously-developed condensation model. Two optical techniques are employed: laser particle image velocimetry, which is used to characterize the cross-section secondary flows, and planar laser-induced visualization, which is employed for the first time to obtain the condensation pattern. The experimental measurements are conducted at two different working points and for two different three-way junction designs, being in agreement with 3D CFD simulations. Particularly, the overall luminosity captured in the experiments presents the same trends than the numerical condensed mass fraction. This innovative validation proves that a CFD model employing a psychrometric-based condensation submodel can be used as a tool to quantify the condensation produced in a three-way junction. The proposed tools are shown to be helpful for the development of advanced LP-EGR systems to reduce NOX,CO2 and particulate matter emissions during engine warm-ups.

Heat transfer coefficient and cross-sectional flow structure in condensation of steam in an inclined tube at a low mass flux

Condensation of steam at a low mass flux inside an inclined tube was experimentally investigated to aid the optimal design of air-cooled passive heat exchangers for advanced LWRs. While varying downward inclination angle from 0 to 90°, the heat transfer coefficient monotonically improved by more than 15% while previous studies that have used refrigerants have reported that the optimal angle is between 15 and 30°. To interpret the conflicting trends observed, the cross-sectional structures of the condensing flow were visualized. Stratified flow was the only type of flow noted; there was no transition to the annular flow typically observed during two-phase flow of refrigerants in a vertical tube. The observed variation in the condensation heat transfer of steam at low mass flux, with respect to the extent of downward inclination, was well predicted by a mechanistic condensation model for stratified flow that incorporates the cross-sectional stratification angles of condensates.

Design of LQR Excitation Controller of Synchronous Condenser in HVDC System

As a kind of reactive power compensation equipment,a synchronous condenser is widely used in High Voltage Direct Current(HVDC) transmission system due to its small influence on the regulation ability and high strong excitation ability. In this paper,the practical state space model of the synchronous condenser is established and the parameters of the model are calculated. The linear quadratic regulator ( LQR) Controller for excitation system is designed and the controllability and stability are analyzed. In order to verify the voltage support ability and dynamic response performance of LQR excitation controller,the simulation is carried out in MATLAB/SIMULINK. The simulation results show that the grid voltage fluctuation can be quickly quelled and the strong excitation function of synchronous condenser is quickly exerted.

Perturbation of charge density waves in 1T−TiSe2

In this study, using low-temperature scanning tunneling microscopy (STM), we focus on understanding the native defects in pristine \textit{1T}-TiSe$_2$ at the atomic scale. We probe how they perturb the charge density waves (CDWs) and lead to local domain formation. These defects influence the correlation length of CDWs. We establish a connection between suppression of CDWs, Ti intercalation, and show how this supports the exciton condensation model of CDW formation in \textit{1T}-TiSe$_2$.