A Study on Strengthening Standards for Fire Prevention of Anti-freeze Electric Heating Cable

As per the fire statistics survey of 2019, 56.5% (152 cases) of the entire fire accidents (269 cases) caused by heating cables were due to electrical factors. Therefore, in the present work, the electrical factors responsible for heating cable fire have been analyzed, and fire prevention measures have been demonstrated through related reproduction experiments. According to heating cable fire statistics, the fire in anti-freezing appliances (heating cables), except for fires caused by electric cable arcing and other unknown factors, can be classified into four types based on installation configurations. These configurations have been classified and tested according to the Technical Regulations for Electrical and Telecommunications Products and Components (K 10013). The results of a comparative experiment on anti-freezing appliances (heating cable) revealed that the configuration “a type of water pipe with a heating cable wrapped around the water pipe and insulation on the outside” showed the highest temperature among the four installation arrangements. Additionally, the maximum difference between the test temperature (K 10013) and the actual temperature was 40 ℃.

Design features of a high-vacuum steam jet pump and some results of its tests

This paper presents an original design of a high-vacuum steam jet pump in which a heater made of a heating cable is immersed in a working fluid located in a stainless steel boiler. At the same time, the boiler itself is vacuum isolated from the pump housing. There is also a heater made of a heating cable in a stainless steel shell, made in the form of a spiral and immersed in a working fluid. Such an arrangement of the heater is possible only when a liquid with a homogeneous chemical composition and a low saturated vapor pressure is used as a working fluid in high-vacuum pumps.

Leakage detection of water pipelines based on active thermometry and FBG based quasi-distributed fiber optic temperature sensing

Water pipelines are the efficient and reliable way for water transportation. Leakage of pipelines can lead to tremendous waste of water resources and large economic loss. In this paper, a novel leakage detection method was proposed based on active thermometry and fiber Bragg grating (FBG) based quasi-distributed fiber optic temperature sensing. In this method, the thermal sensing cable was fabricated by coupling heating cable with quasi-distributed temperature sensors. The heat was introduced by the heating cable and the temperature response was measured by the quasi-distributed fiber optic temperature sensor concurrently. The leakage can be detected and located by identifying the local low values in the temperature profile along the pipelines. The feasibility of the proposed method was validated by finite element simulation and experimental investigation. Good agreement between simulation and experimental study was achieved. The results confirmed the effectiveness of the proposed method for leakage detection.

Cointegration for structural damage detection under environmental variabilities: An experimental study

An intricacy in vibration-based structural damage detection (VSDD) relates to environmental variabilities imposing limitations to the damage detectability. One method that has been put forth to resolve the issue is cointegration. Here, non-stationary vibration features are linearly combined into stationary residuals, which are then employed as damage indices under the assumption that the non-stationarity is governed by environmental variabilities. In the present paper, the feasibility of using cointegration to mitigate environmental variabilities while retaining sensitivity to damage is examined through an experimental study with a steel beam. A temperature-based environmental variability is introduced to the beam by use of a heating cable, while damage is emulated by adding local mass perturbations. The vibration response of the beam in different environmental and structural states is captured and utilized as features in a cointegration-based damage detection scheme. The performance of the scheme is assessed and compared to that of a scheme not accounting for the variability on the basis of the false positive ratio (FPR), the true positive ratio (TPR), and the area under the receiver operating characteristic curve (AUC). The results show that cointegration effectively mitigates the temperature variability and allows for an improved damage detectability compared to that of the scheme without a mitigation strategy

Hygrothermal Analysis of Masonry Wall with Reed Boards as Interior Insulation System

When the masonry walls of buildings under heritage protection need to be restored and thermally improved, the only option is to use an interior insulation system. This is also the riskiest method of insulating walls in cold climates. Capillary active interior insulation systems have been proven to be the most reliable, minimizing the risk of mold growth and decay caused by condensation. They have also been proven to be less risky in wind-driven rain. The building studied is situated in a heritage-conservation area in downtown Tartu, Estonia, and therefore cannot be insulated from the exterior. This paper compares the hygrothermal performance of four different interior insulation systems with and without a heating cable and vapor barrier. In the first case, Isover Vario KM Duplex UV was placed between reed panels. In the second case, reed panels were used without the vapor barrier. Data loggers were applied between the reed panels and the original wall and inside the room to measure temperature and relative humidity in one-hour intervals. Exterior temperature and relative humidity values were taken from the Estonian University of Life Sciences Institute of Technology weather service station. In addition to the measurements taken in the case study building, calculations were made using heat-air-moisture (HAM) Delphin software to simulate the situation. The use of a smart vapor retarder (Isover Vario KM Duplex UV) with reed panels in the interior insulation system reduced the relative humidity level inside the wall. The vapor retarder improved the drying-potential compared to the interior insulation system without the vapor barrier.

An experimental bench for studying the processes of freezing-thawing of soil in the laboratory

In the article, the authors consider the problem of building buildings and structures on permafrost soils, provides a brief overview of ways to preserve the frozen state of base soils. The analysis of scientific works devoted to the thermal interaction of an engineering structure with permafrost soils is given. Conducting full-scale experiments in the conditions of the spread of permafrost soils is a laborious and expensive undertaking, therefore, as part of the research, an experimental stand was developed that allows one to study the processes of freezing and thawing soils in laboratory conditions. The experimental stand is a soil tray with rigid walls and a bottom with overall dimensions in the plan of 1000x1000 mm and a height of 1000 mm. The open system was modeled by placing perforated pipes at the bottom of the tray with a heating cable installed inside the pipes, maintaining a positive water temperature. To ensure one-sided and plane-parallel freezing, the side surfaces and the bottom of the tray were glued with a heater. To fix the temperature of the soil in the experimental bench and the air temperature in the freezer, the TEREM 4-1 measuring complex with DTS 1-1 soil temperature sensors is used. To fix the movements of the soil base in the experimental bench, ICH-50 dial indicators with a division price of 0.01 mm on a telescopic magnetic stand are used. To study the processes of freezing thawing of soils, the authors propose a series of experimental studies on water-saturated loams in laboratory conditions. A description is given of an experimental bench with a model of a thermostabilizer for studying the processes of freezing-thawing of base soils in laboratory conditions, and a methodology for conducting experimental studies is described.

CHIPOFIL: A pilot study assessing the feasibility of HIPEC without extracorporeal circuit

BackgroundHeated intraperitoneal chemotherapy (HIPEC) is currently performed using an external circuit including a heating device and a pump. Available devices have several drawbacks in terms of costs, technique (flow surges due to blocked tubes) and staff safety, hindering a wider use. In a previous preclinical study conducted in animals, we placed a heating wire within the abdomen to achieve and maintain hyperthermia. Our results showed this technique is safe and effective. The present pilot study was conceived as the first use of such a device in humans, aiming to confirm its safety and efficacy.MethodsThis was a pilot study designed to include 13 patients undergoing HIPEC. Two sets of the prototype were placed within the abdominal cavity, one in the supramesocolic and one in the inframesocolic space. The target temperature was 42–43 °C during 30–90 min according to the protocol defined for each patient. The time to set up, heat and dismantle was measured. All complications were recorded during the first postoperative year and evaluated by an independent committee.ResultsNine women and four men were included. The median time to set on the device was 25 min. The target temperature was obtained in a median of 14 min and maintained uniform and homogeneously distributed within the abdomen for the scheduled duration. A permanent stirring of the viscera was performed. No thermal injury or device-related complications were observed. There were two anastomotic leaks (only one requiring reoperation), two hemoperitoneum requiring reoperation, one evisceration and one gastroparesia.ConclusionsA heating cable within the peritoneal cavity can achieve safe, simple, fast and efficient HIPEC.