Price competition model in decentralized and centralized supply chains with demand disruption

Purpose: The paper studies the price competition of a supply chain with one supplier and two competing retailers under occasional demand disruption. Design/methodology/approach: The supply chain is either decentralized or centralized. The demand disruption for two retailers occurs with different probability. We analyze the effect of occurrence probability of demand disruption on the optimal prices of the supplier and two retailers. Findings: We find that the profits of supplier, retailers and supply chain are decreasing with the occurrence probability of demand disruption. Originality/value: It is helpful for supply chain members to adjust the original contracts to demand disruption.Peer Reviewe

Theoretical and Experimental Research on The Optimal Displacement Ratio of Rotary Two-Stage Inverter Compressor With Vapor Injection

Displacement ratio is one of the most important parameters of designing rotary two-stage inverter compressor with vapor injection, which decides the COP (Coefficient of Performance) of the compressor. The optimal displacement ratio can bring about the highest COP. The mathematical model of the optimal displacement ratio of rotary two-stage inverter compressor with vapor injection has been developed and verified with the test data. It can be seen from theoretical and experimental research that the optimal displacement ratio of compressors in different working conditions can be obtained accurately by the mathematical model introduced in this paper

Research on Two-stage Rotary Compressor with Refrigerant Injection for Cold Climate Heat Pump

As an promising heating application of environmental conservation and energy conservation, air-source heat pump systems has been spreading. However, conventional heat pump systems have problems remaining, such as inadequate heating capacity and reduced performance under low environmental temperature condition. To solve these problems, we developed a two-stage rotary compressor for household R32 air-source heat pump system. We analyzed the thermodynamic characteristics of two-stage rotary compressor with refrigerant injection used in heat pump system with economizer. It is found that the two-stage rotary compressor can enhance heating capacity and performance of R32 heat pump under cold climate markedly

Study on the Performance of CO2 Two-stage Rotary Compressor in Freezing and Cold Storage Conditions

This paper describes a new type CO2 two-stage rotary compressor for cold storage and freezing of food. A two-stage compression form with an upper cylinder (first-stage) and a lower cylinder (second-stage), unique oil road structures and technical parameters have been used in the rotary compressor to increase the performance. The results indicating that the optimized CO2 two-stage rotary compressor has a significant performance advantage, which the coefficient of performance (COP) increases by 4.4% ~ 6.7%

Numerical Analysis and Optimization for Hydrodynamic Lubrication in Journal Bearings of Rotary Compressor

Based on the average Reynolds’ equation of hydrodynamic lubrication, the axis locus and the minimum oil film thickness of the journal bearings under the dynamic load were numerically solved in this paper, and the movement and bearing characteristics of the compressor bearings at different rotation speeds were analyzed to evaluate the influence of the friction loss of the journal bearings on the performance of the rotary compressor. The simulation results indicated that the minimum oil film thickness of the sub bearing is smaller than the critical oil film thickness at low rotation speed (n ≤ 1800 rpm), therefore, the friction power increases significantly with the decrease of rotation speed. The effects of width-diameter ratio, clearance and viscosity of lubricating oil on the improvement of minimum oil film thickness were further analyzed. By optimizing the width-diameter ratio of the bearing, the load carrying capacity of the oil film is improved, and the friction power of sub bearing reduces by more than 80%. The experimental results showed that the performance of rotary compressor can be improved by more than 1% at low rotation speed

Development of Large-And-Small Volume-Switching Rotary Compressor for Residential Multi-Connected Air-Conditioner

Residential Multi-Connected Air-Conditioner(RMAC) are widely used in urban residential in China, but they have low energy efficiency problems in daily use. They are mainly due to the air-conditioning habits of Chinese residents in part space and part time , Which makes RMAC most of the time only 1-2 indoor units are turned on, and 60% of the operating time is at a low load rate of less than 30%. During low load operation, the compressor\u27s efficiency drops sharply, and there is also the problem of frequent start and stop when the minimum output is too large. In order to solve this problem, a large-and-small volume switching compressor suitable for RMAC is developed. The compressor can choose single-cylinder small-volume operation or twin-cylinder large-volume operation according to the change of system load. The new compressor technology for RMAC improves the energy efficiency by 124% under 10% load, and avoids the problem of frequent start-stops at low loads, making RMAC more energy efficient and more comfortable