Refrigeration Power Research Articles

A lower temperature difference of the elastocaloric effect by natural rubber

Owing to its high efficiency and specific refrigeration power, elastocaloric refrigeration is a promising technology that is potentially endowed with replacing the conventional steam compression refrigeration. Here, experimental results on the elastocaloric cooling process of natural rubber are presented, achieving a maximum temperature drop during unloading of the natural rubber of 41.30 K with a temperature difference of 68 K between hot and cold ends at an ambient temperature of 253.13 K. Moreover, analytical equations are provided for the temperature variation of cooling and heating natural convection as a function of Fo and Bi numbers, which are fitted to the experimental data and can be used to provide predictions for future elastocaloric refrigeration equipment. Thus, the study unravels the potential of natural rubber as a promising elastocaloric material and its key properties for refrigeration technology.

Study of the operating characteristics of a pump-driven thermosyphon loop with gas–liquid separation

Pump-driven thermosyphon loop (PDTL) is a highly efficient cooling method for air-conditioning systems in data centers. Typically, the refrigerant in gas–liquid two-phase state leads to significant pressure drop in pipes following evaporator, which results in more energy consumption for data centers cooling. This study proposes a novel PDTL with gas–liquid separation (PDTLGLS), aiming to separate the gas–liquid phase refrigerant into liquid phase and gas phase, to reduce pressure drop following evaporator and improve the PDTL performance using a gas–liquid separator. Driven by the pressure difference between the gas–liquid separator and the reservoir, the gas-phase refrigerant is condensed into liquid-phase refrigerant back to the reservoir and the liquid-phase refrigerant returns to a reservoir directly without heat exchanging. This paper firstly conducted a theoretical analysis of PDTLGLS. Then the experiments were conducted using R134a to investigate the influence of refrigerant flow rate and heating power on the performance of PDTLGLS. Furthermore, transient characteristics of the PDTLGLS were experimentally analyzed by varying the heating power. The experimental results show that the PDTLGLS achieves 36.8%-53.3% less heat dissipation temperature difference (from evaporator to condenser) and 28.3%–33.3% higher EER than traditional PDTL, and lower dryness could enlarge the PDTLGLS advantages. Furthermore, both analysis results and experimental results show that the PDTLGLS can adjust to diverse refrigerant mass flow and heating power via the self-regulation of the liquid height in the gas–liquid separator, which implies that the PDTLGLS is an effective way to enhance the traditional PDTL performance and could sustain stable operation across a broad spectrum of operating conditions.

Re-Imagining the Cooling Systems for Markets in Developing Countries: A Conceptual Analysis of a Footstep Powered Cooler

Preserving perishable food items like fruits and vegetables in local markets of developing countries is a significant challenge due to the lack of affordable and sustainable cooling solutions, resulting in high food loss, economic burden, and environmental waste. This paper presents a conceptual analysis of a footstep-powered cooler (FPC) system that harnesses the energy generated from footstep movement to power refrigeration systems. The study developed a Minimal Viable Product (MVP) consisting of a piezoelectric plate connected to a voltage doubler circuit to measure the energy generated per step. Results showed that a single footstep on a 0.15 x 0.15 m tile with four piezoelectric plates connected in series generated 0.8 J of energy. However, when extrapolated to the scale of a market, the energy generated from footsteps fell significantly short of the energy requirements for refrigeration. The study suggests optimizing tile placement, exploring other piezoelectric materials, and improving energy extraction efficiency through circuit modifications as potential strategies to enhance energy output to meet the required energy demands. While footstep-generated energy alone may not be sufficient, it represents a promising and sustainable approach to preserving perishable food in local markets, reducing food loss, and improving overall efficiency in the food supply chain.

A novel control strategy for active battery thermal management systems based on dynamic programming and a genetic algorithm

An appropriate active battery thermal management system (ABTMS) control strategy should be able to extend battery life, improve battery capacity consistency and reduce system energy consumption; however, these three purposes are mutually conflicting. To address this conflict, this paper proposes representing the control of the ABTMS as a dynamic multiobjective control problem, with the battery state of health (SOH), battery SOH difference and system energy consumption as the optimization objectives and the airflow rate and refrigeration power as the control variables. Weight coefficients are proposed to couple the multiple objectives. Next, a combined control strategy comprising dynamic programming and a genetic algorithm is developed to obtain the optimal weight coefficient set and calculate the optimal path of the ABTMS that minimizes the total cost of the multiple objectives. Experimental results indicate that the combined strategy effectively balances the three optimization objectives to comprehensively optimize performance. Compared with the performance of a rule-based multiparameter control strategy, the proposed combined control strategy decreases the battery capacity attenuation rate by 3.7%, saves system energy consumption by 22.4%, and improves battery capacity consistency by 23.3%. These findings provide a basis for more efficient and intelligent control strategies for ABMTSs.

Energy and Exergy Analysis of an Innovative Power/Refrigeration Cycle: Kalina Cycle and Ejector Refrigeration Cycle

This study presents a thermodynamic analysis of a new combined power/refrigeration combined cycle. The combined cycle is comprised of two innovative cycles: Kalina cycle (KNC) and ejector refrigeration cycle (ERC) for power and refrigeration production, respectively. Recovery of heat process is involved in the design of the cycle to rise the energetic and exergetic efficiencies: emitted heat by the KNC is absorbed by the ERC in order to generate cooling. Effects of variation in KNC operational conditions which have direct effects on turbine power production capacity (temperature and pressure of the working fluid flow at the turbine inlet) on performance evaluation parameters of the system (energy efficiency, exergy efficiency, energetic and exergetic content of produced refrigeration and net power) are investigated. A detailed discussion of the results is also reported. Energetic and exergetic efficiency results are substantially dominated by generated power, i.e., KNC parameters which impose direct effect on turbine power production performance is of superior importance to rise the energy and exergy efficiencies.

The design of YBCO binary current leads and its electromagnetic-thermal coupling analysis based on PEEC and finite volume method

A superconducting magnet system is developed for the application of high-frequency gyrotrons at Wuhan National High Magnetic Field Center, China. The operating cost for the magnet is dominated by refrigeration power. To reduce the heat load for cryogenic systems, a pair of YBCO binary current leads is designed by consideration of the industrial concentration of type II high-temperature superconducting YBCO material. In this paper, a simulation model is proposed to perform the electromagnetic-thermal coupling analysis of these YBCO binary leads under different operating conditions by combining a partial element equivalent circuit method and finite volume method. The simulation code can improve computational efficiency and enable high-accuracy coupling between the electromagnetic field and heat transfer process. In the steady state, the heat leakage at the 4.2 K cold end of the YBCO binary leads depends mainly on the geometric parameters of the YBCO tape, especially the cross-sectional area of the copper layer in the YBCO tape. The cooling mode and liquid helium level also have a significant impact on the heat leakage level. The optimal outer diameter of the normal copper section is identified, and the optimum value is largely influenced by the effective cooling power imposed on the cold end of the normal copper section. In the transient state, simulations for the charging process and the loss of cooling accident are performed, along with a detailed analysis of the electromagnetic-thermal response features of the leads under these conditions. The results indicate that the YBCO binary current leads possess high thermal stability and an ample time margin for the magnet system to be demagnetized.

Comparative thermodynamic analysis of China Spallation Neutron Source second phase (CSNSII) SRF system cooling Scheme

The China Spallation Neutron Source second phase (CSNS-II) accelerator upgrades consist of three major components: linac energy upgrade from 80 MeV to 300 MeV, injection system upgrade, and new magnetic alloy dual harmonic cavities. There are ten double spoke cavities cryomodules and eight elliptical cavities cryomodules in total. A comparative thermodynamic analysis of the superconducting radio frequency (SRF) systems can be of great importance to select a reliable, cost-effective and easy-maintenance cooling schemes. This is particularly critical for SRF systems that require long-term operation. A comparative thermodynamic analysis of both types of cooling schemes for SRF systems, referred to as Scheme 1 (a cryogenic distribution system with distributed heat exchangers) and Scheme 2 (a cryogenic distribution system with central heat exchangers), was presented in this paperThe length and size of process transfer lines, as well as the heat loads subjected to their components, of cryogenic distribution systems were introduced. In addition, the unsteady state cooldown process for the CSNS-II SRF cryomodules was investigated. The analysis results that included temperature and pressure profiles along the linac distance, as well as distributions of JT expansion effectiveness, mass flow rate, and cryomodule exegetic efficiency. Furthermore, the exergy analysis and refrigeration power are investigated using a neural network optimized by a novel sparrow search algorithm genetic algorithm (SSA-GA). Results show that, Scheme 1 is more advantageous than Scheme 2 because it can save maintenance time. From 300 K to 4.5 K, the total cooldown time of SRF cryomodules is approximately 28 h. The maximum ΔP is around 1.1 bara, which can be considered in the acceptable range. The prediction of ηex is stable at the 7th epoch after being optimized by SSA-GA, and the MSE is 1 × 10-5. And the error between the predicted and true values of the BP neural network after SSA optimization is very small (less than 0.1%), approaching zero, indicating that the BP optimized by SSA achieves good prediction. This paper's work can serve as a solid foundation for the construction and operation of the CSNS-II.

The dynamic performance of a compact LN2 depressurization cryocooling system

Liquid nitrogen (LN2) has been widely used as a cooling medium. A compact LN2 depressurization cryocooling system can be used as a portable cooling unit to satisfy flexible cooling requirements. A prototype of this cryocooling system which was mainly composed of a LN2 tank, a LN2 pump, a heat exchanger and a vacuum pump was built and tested. In the test, the lowest cooling temperature could reach below 65 K, and the average temperature of 0.95 m3 LN2 dropped from 73.5 K to 68.1 K after 6814 s of running. The average refrigeration power reached 1326 W at 65 K. Meanwhile, the system operation process was simulated through theoretical analysis and modeling. Simulation results were nearly consistent with experimental results and the dynamic operating characteristics were well captured. For the experimental apparatus, the LN2 supplement and shutdown of the liquid-ring pump affect the system cooling performance, and modeling results show that the cooling efficiency decreases with the LN2 volume flow rate V̇LN2 increasing whenV̇LN2 > 0.9 m3/h.

Full-scale utilization of geothermal energy: A high-efficiency CO2 hybrid cogeneration system with low-temperature waste heat

The utilization of geothermal energy is becoming increasingly important in the current transition towards sustainable energy sources. Among the various methods of utilizing geothermal energy, the use of hybrid geothermal power plants that exploit CO2 fluid for preheating in electricity generation has been identified as an attractive approach. Additionally, the shallow ground source heat pump (SGSHP) has been proven to be superior in previous experimental studies. However, the full-scale utilization of geothermal energy, through generating electricity from geothermal power plants and applying waste heat with SGSHPs for auxiliary heating, needs further exploration. This study proposes a novel CO2 hybrid geothermal system that incorporates a GSHP heating system. The hybrid geothermal system uses CO2 as the underground working fluid, and the electricity and waste heat are used to assist the GSHP for heating, ventilation, and air conditioning. The proposed system can produce 11.41 MW of electricity, 80 °C of hot water, and 34.76 MW of cold energy by driving 50 MW of the geothermal heat. Through a comprehensive analysis of the economy, energy, exergy, and environment, the results demonstrate that the maximum exergy damage of the refrigeration power cycle is 37999.33 kW, which has the highest exergy losses. The exergy loss of the steam turbine heat power conversion in the geothermal power generation process is the highest, but this loss can be effectively reduced through heat integration. The optimal cooling temperature of the coupled system should be set at 8 °C, and it has a good investment prospect. In summary, the CO2 hybrid geothermal system can realize effective cogeneration and fully utilize geothermal energy. Therefore, it has great potential to contribute to the transition towards a sustainable energy future.

Thermal performance analysis and experimental verification of lithium-ion batteries for electric vehicle applications through optimized inclined mini-channels

Power units (i.e., batteries) of electric vehicles (EVs) generate heat while being charged or discharged, which deteriorates their performance and reliability over time. This paper investigates a comprehensive spectrum of geometric and thermo-fluidic parameters of a liquid coolant flowing through mini-channels. These are embedded in the surface of an EV battery to curtail overheating. Design parameters such as aspect ratio and angular orientation of the mini-channels were varied randomly to investigate several geometric configurations that are scarcely intuitive. The coolant mass flow rate and the fluid inlet temperature were also varied through a large dataset of randomly distributed values. A real-time EV driving cycle was implemented alongside an experimentally validated model to evaluate the battery operation, which evidenced the complex dependence of the battery’s thermal state with different levels of cooling retrofitting. The study also analyzed the parasitic power consumption arising from the pumping and cooling energy demands to drive the coolant system to achieve an optimally designed retrofit for a reliable battery performance. It was found that the mini-channel parameters considerably affect the thermal performance of the battery. However, the optimized case was found to have a minimum temperature difference in the battery and a minimum power requirement. The case with a fluid inlet velocity of 0.13 m/s, a fluid inlet temperature of 312.9 K, an aspect ratio of 1.7, and an inclination angle of 4.9° was found to be the most suitable, leading to a refrigeration power requirement of 0.85 W only. The battery temperature after the end of the driving cycle was maintained at 313 K.

Process design and optimization of single mixed-refrigerant processes with the application of deep reinforcement learning

Deep reinforcement learning approach is considered for the design and optimization of SMR (Single Mixed Refrigerant) cycles with which the refrigeration power is minimized. Deep Q-Network (DQN) agent is programmed with Python®, which is interacted with a process simulator UniSim Design®, as an environment, through the delivery of decision with MATLAB®. The optimization goal is achieved by designing a reward function such that specific power requirement is minimized, subject to the constraint of minimum temperature difference for the heat transfer. The case study focuses on the design of the SMR cycle for the liquefaction of lean and rich natural gas feeds. GA (Generic Algorithm) optimization framework is also constructed and applied for the case study. Almost the same or similar computational performance between the DQN and the GA methods is observed for finding optimal solutions. For the case study, the specific power required for the liquefaction process is reduced by 15.7% and 13.4% through DQN optimization for the cases of lean and rich feeds, respectively, compared to base cases. The case study clearly demonstrates the applicability of the reinforcement learning which can effectively deal with the optimization problem having complex interactions and high nonlinearities.

Development of an artificial neural network for the prediction of the thermodynamic property enthalpy in the NH3-H2O mixture

There are many different methodologies for calculating the enthalpy thermodynamic property in the ammonia-water mixture, which is mainly used in the analysis of absorption refrigeration systems and power, so its prediction becomes essential not only for theoretical evaluations, also for the design of industrial equipment. In this work an alternative methodology, an artificial neural network (ARN) is approached. Two neural networks were designed: ARN A and ARN B. ARN A has three main input variables: Pressure (P), Temperature (T) and Ammonia Concentration in the mixture (x), to obtain the output variable: enthalpy. ARN B has as a particular case that the variable Temperature (T) is replaced by the phase in which the mixture is found (q); both networks were compared with experimental data reported in open literature and with the EESTM software. The two networks are capable of predicting the enthalpy of the Ammonia-Water mixture, ARN A with an acceptable prediction range between 100 kPa and 11,000 kPa, and ARN B from 5,000 kPa to 10,000 kPa.

Influence of drive chamber discharging process on non-linear displacer dynamics and thermodynamic processes of a fluidic-driven Gifford-McMahon cryocooler

Abstract Continuous effort is made on Gifford-McMahon cryocoolers (GMC) to amplify its refrigeration power, so they can be used to cool the cryopumps, high Tc magnets and development of efficient small-scale hydrogen liquefiers, etc. The fluidic-driven GMC is considered to be more reliable and prominent candidate than the mechanically-driven GMC due to its structural simplicity and reliability. Nonetheless, cooling mechanism of the fluidic-driven GMC is complicated, as the displacer motion inside the displacer cylinder is simultaneously controlled by the pressure difference between drive chamber and compression/expansion chamber. Different paths of displacer can be traced inside the displacer cylinder for different drive-chamber discharging process, hence, pressure–volume power of compression and expansion chambers, and refrigeration power changes. A theoretical study is conducted in present paper to visualize the influence of drive-chamber discharging process on the thermodynamic characteristics of fluidic-driven GMC for the first time. Thermodynamic cycles are drawn at the expansion chamber of the fluidic-driven GMC for different values of drive-chamber discharging process for two types of valve timing arrangements. Energy and work loss behaviors in different components of the GMC are also analysed. Adequate experimental investigations have also been carried out on a fluidic-driven displacer type GMC to verify the simulation results.

Design and cooling performance analysis of the temperature-controlled pile (TCP) in permafrost regions

To accelerate the refreezing time of cast-in-place piles in permafrost regions and improve their long-term stability, this paper proposes a novel TCP based on solar refrigeration. The TCP consists of a solar power system (SPS), a vapor compression refrigeration system (VCRS), and a pile. Then, the cooling effect of the TCP was carried out by the model test and the numerical simulation. The model test results show that both the evaporating temperature and the condensing temperature are positively correlated with the ambient temperature, but the coefficient of performance (COP) is negatively correlated with the ambient temperature. The numerical simulation results show the TCP can significantly shorten the refreezing time. The higher the mean annual ground temperature (MAGT), the more significant the acceleration effect. With the increase in the TCP working time, the pile wall permafrost temperature tends to be stable, and the cooling radius increases continuously. The TCP can restrain the degradation rate of the permafrost table, which can be further reduced by increasing the refrigeration power and the refrigeration tube space. The freezing force between the frozen soil and the pile is enhanced due to the cooling effect of the TCP. The TCP bearing capacity is >1.5 times that of a traditional pile (TP). The effect of improving the bearing capacity of the pile can be achieved by increasing the refrigeration power and refrigeration tube space. The conclusions summarized in this paper can provide references for the design and construction of piles in permafrost regions.

Research on thermal comfort of commercial vehicle and economy of localized air conditioning system with thermoelectric coolers

In commercial vehicles, the power consumption of the traditional air conditioning system used to cool an entire cab is high. In most cases, there is only one driver in vehicle, so adjusting the local thermal environment around the driver can reduce much energy waste. In this paper, a localized air conditioning system based on thermoelectric cooling (TEC) devices was constructed, and its performance characteristic were studied to find the optimal operating conditions in practice. The relationship between the refrigeration power and the operating current of the device was studied. A bench test was carried out to evaluate the performance of the device and the accuracy of the simulation. This paper selected a commercial vehicle cab for the application of the TEC system. The thermal comfort of human body in cab and the economy of local air conditioning system was analyzed by the method of computational fluid dynamics. The driver’s thermal comfort was analyzed based on equivalent temperature and thermal comfort deviation. The results show that when the cooling power is 3000 W, the overall thermal comfort deviation of human body under local thermoelectric refrigeration is 7.94% higher than that under traditional refrigeration. When the duty ratio of the centrifugal fan governor is about 40%–60%, the semiconductor cooling device has excellent refrigeration performance and low energy consumption, which can not only ensure the thermal comfort of the driver but also reduce the energy consumption of the air conditioner.

Comprehensive evaluation of nano refrigerants: A review

Refrigeration plays a significant role in today's modern lifestyle. It has a wide range of applications in both the domestic and commercial sectors. Most of these systems work on the principle of a vapour compression refrigeration system, which operates on a work-based cycle. Natural refrigerants such as CFCs, HCFCs, HFCs, HCs, and their blends have all been used in various ways over the years. Some of these refrigerants are found to be a major threat to the environment, destroying the ozone layer and increasing global warming potential. Since that discovery, researchers have been working to produce new refrigerants that address the aforementioned environmental issues together while increasing the performance of existing systems. The use of nanofluids in refrigeration systems is one of these recent breakthroughs in refrigeration systems. Nanoparticles, which can only be measured on a nanoscale, are used to develop a nanofluid. Nano refrigerants are a colloidal suspension of nanoparticles in the base refrigerant and they gradually evolved as one of the promising efficient heat transfer fluids in various thermal engineering applications because of their improved thermophysical properties. This paper primarily focuses to examine and understand the effect of nanoparticles (such as TiO2, Al2O3, CuO, SiO2, ZnO, ZrO2, ZnO/SiO2, diamond, etc.), when integrated with regular refrigerants, on the performance of refrigeration systems using various parameters viz. pressures drop during suction and discharge, refrigeration effect, power consumption, and COP.

Continuous measurement boosted adiabatic quantum thermal machines

We present a unified approach to study continuous measurement-based quantum thermal machines in static as well as adiabatically driven systems. We investigate both steady-state and transient dynamics for the time-independent case. In the adiabatically driven case, we show how measurement-based thermodynamic quantities can be attributed geometric characteristics. We also provide the appropriate definition for heat transfer and dissipation owing to continuous measurement in the presence and absence of adiabatic driving. We illustrate the aforementioned ideas and study the phenomenon of refrigeration in two different paradigmatic examples: a coupled quantum dot and a coupled qubit system, both undergoing continuous measurement and slow driving. In the time-independent case, we show that quantum coherence can improve the cooling power of measurement-based quantum refrigerators. Exclusively for the case of coupled qubits, we consider linear as well as nonlinear system-bath couplings. We observe that nonlinear coupling produces cooling effects in certain regimes where otherwise heating is expected. In the adiabatically driven case, we observe that quantum measurement can provide significant boost to the power of adiabatic quantum refrigerators. We also observe that the obtained boost can be larger than the sum of power due to individual effects. The measurement-based refrigerators can have similar or better coefficient of performance in the driven case compared to the static one in the regime where heat extraction is maximum. Our results have potential significance for future application in devices ranging from measurement-based quantum thermal machines to refrigeration in quantum processing networks.

Deconstruction and reconstruction of heat driven absorption refrigeration and absorption power cycle with 3-D methods

Advanced absorption cycles, such as the generator-absorber heat exchange (GAX) absorption refrigeration cycle and Honigmann power cycle, are not easy to be intuitively expressed in traditional T-s or P-h diagram, due to their complex heat and mass coupling relationship. With 3-dimensions (3D) methods, additional information can be intuitively expressed which can motivate researchers to propose creative and novel advanced absorption cycles with complex internal heat and mass coupling. In this study, a classic high-performance branched GAX (b-GAX) was graphicly analyzed by introducing 3D methods. The b-GAX cycle was deconstructed in 3D space and reconstructed by projecting the cycle to traditional P-T and P-X plates. Implicit parameters like intermediate concentration and deflation ratio were exhibited intuitively. The performance of the system has a better linear correlation with these new parameters than operation parameters. The Honigmann progress was also graphicly expressed with the 3D methods. By extracting implicit parameters, the new method is expected to play a role in helping to understand complex thermodynamic cycles and propose advanced high-performance cycles.

Thermal performance of a simplified parallel power and refrigeration combined cycle with refrigeration as the main task

• Simplified parallel power/refrigeration combined Kalina cycle was studied. • Obtaining larger refrigeration energy is the main purpose of the new combined cycle. • There is no desorption process of basic solution in the simplified cycle. • Simplified cycle was evaluated by efficiencies based on energy quality and quantity. • Simplified cycle can maintain high performance with much larger refrigeration capacity. A simplified parallel power and refrigeration combined cycle based on the Kalina cycle (SPPRA-KC) using ammonia-water as working fluid is proposed and studied, in which refrigeration is taken as the main task and the refrigerant plays a leading role in improving the concentration of work solution. The turbine exhaust vapor is utilized to heat the work solution fed to the refrigeration sub-cycle, resulting in more refrigeration energy produced. Parameter analysis was conducted under temperatures of heat source/cooling water of 400 °C/30 °C from the perspective of energy quantity and quality. To obtain larger refrigeration capacity and power recovery efficiency, the dew point temperature of work solution and bubble point temperature difference in the boiler shall be as higher as possible and properly increased, respectively, which will cause more irreversible losses in the cycle, resulting in lower effective exergy efficiency. When optimizing the cycles with work concentration of 0.5 based on the effective exergy efficiency, the power recovery efficiency of the SPPRA-KC is 34.8% much higher than that of the related original cycle (PPRA-KC) due to much larger refrigeration capacity, and the effective exergy efficiency of the SPPRA-KC is 1.67% and 12.4% relatively higher than those of the PPRA-KC and the Kalina cycle, respectively. Besides, the main exergy destruction of the SPPRA-KC occurs in the boiler, absorbers, exhaust heat source and turbine.

Parametric study and optimization of the cryo-magnetic system for EU DEMO at the pre-conceptual design phase

The pre-conceptual design phase of the EU DEMO magnet system relies on mechanical, electromagnetic and thermal-hydraulic analyses of different conductor designs for the Toroidal Field (TF) coils, the Poloidal Field (PF) coils and the Central Solenoid (CS) magnet. The cryo-magnetic system includes the superconducting magnets cooled by forced flow of supercritical helium at about 4.5 K, the cryo-distribution lines and valve boxes, and the cryogenic system with several cold boxes. The present analysis focuses on the cooling requirement of the TF coils with three winding pack options for the cable in conduit conductors based on 2015 DEMO baseline, featuring pancake or layer winding approaches. This analysis methodology would be further developed with the latest conductor designs and more complete heat load assumptions for the future conductor design studies and the specification of the cooling requirements. Parametric studies on the cold source temperature and on the supercritical helium mass flow rate have been performed on the three conductor designs in order to identify for each one the impact of the cooling conditions onto the temperature margin with respect to the current sharing temperature. In this study, the heat load contribution have been limited to the estimation of the neutron heating and some joint resistance heat loads when available. In addition, Simcryogenics, a dynamic modelling tool developed by CEA, is used to model supercritical helium loops for cooling different conductor designs. An algorithm has been developed to optimize both the cold source temperature and the supercritical helium mass flow, in order to minimize refrigeration power for each conductor design. Optimization studies are analyzed and compared in order to estimate for each TF winding pack design, the impact on refrigeration power. The interest of such quick cross-check analyses is to identify design improvements for the conductors and the cryo-distribution, keeping acceptable temperature margins and minimizing the refrigeration power.