The Experts below are selected from a list of 450 Experts worldwide ranked by ideXlab platform

Chunlu Zhang - One of the best experts on this subject based on the ideXlab platform.

  • dynamic simulation of air to water dual mode heat pump with screw compressor
    Applied Thermal Engineering, 2003
    Co-Authors: Long Fu, Guoliang Ding, Chunlu Zhang
    Abstract:

    Abstract A dynamic model of air-to-water dual-mode heat pump with screw compressor is presented here. The high-pressure and low-pressure segments are divided into three control volumes, including the refrigerant inside tube, the tube wall and the fluid outside tube that is water or air. Time dependent ordinary differential equations are obtained from the mass and energy balances for each control volume. As the compressor, thermostatic expansion Valve (TEV) body, and Reversing Valve have very small thermal inertias, steady-state models are applied for the compression, throttling, and leakage processes. The relationship between the temperature of the saturated liquid–vapor mixture in TEV’s bulb and the temperature of the refrigerant vapor at the evaporator exit is described with a time dependent ordinary differential equation. System simulation is finally carried out with ‘predictor–corrector’ and ‘adaptive integration step’ methods. Simulated results are in good agreement with the measured data, which lead to conclusion that the model can be used as a tool for the product development.

  • dynamic simulation of air to water dual mode heat pump with screw compressor
    Applied Thermal Engineering, 2003
    Co-Authors: Long Fu, Guoliang Ding, Chunlu Zhang
    Abstract:

    Abstract A dynamic model of air-to-water dual-mode heat pump with screw compressor is presented here. The high-pressure and low-pressure segments are divided into three control volumes, including the refrigerant inside tube, the tube wall and the fluid outside tube that is water or air. Time dependent ordinary differential equations are obtained from the mass and energy balances for each control volume. As the compressor, thermostatic expansion Valve (TEV) body, and Reversing Valve have very small thermal inertias, steady-state models are applied for the compression, throttling, and leakage processes. The relationship between the temperature of the saturated liquid–vapor mixture in TEV’s bulb and the temperature of the refrigerant vapor at the evaporator exit is described with a time dependent ordinary differential equation. System simulation is finally carried out with ‘predictor–corrector’ and ‘adaptive integration step’ methods. Simulated results are in good agreement with the measured data, which lead to conclusion that the model can be used as a tool for the product development.

Long Fu - One of the best experts on this subject based on the ideXlab platform.

  • dynamic simulation of air to water dual mode heat pump with screw compressor
    Applied Thermal Engineering, 2003
    Co-Authors: Long Fu, Guoliang Ding, Chunlu Zhang
    Abstract:

    Abstract A dynamic model of air-to-water dual-mode heat pump with screw compressor is presented here. The high-pressure and low-pressure segments are divided into three control volumes, including the refrigerant inside tube, the tube wall and the fluid outside tube that is water or air. Time dependent ordinary differential equations are obtained from the mass and energy balances for each control volume. As the compressor, thermostatic expansion Valve (TEV) body, and Reversing Valve have very small thermal inertias, steady-state models are applied for the compression, throttling, and leakage processes. The relationship between the temperature of the saturated liquid–vapor mixture in TEV’s bulb and the temperature of the refrigerant vapor at the evaporator exit is described with a time dependent ordinary differential equation. System simulation is finally carried out with ‘predictor–corrector’ and ‘adaptive integration step’ methods. Simulated results are in good agreement with the measured data, which lead to conclusion that the model can be used as a tool for the product development.

  • dynamic simulation of air to water dual mode heat pump with screw compressor
    Applied Thermal Engineering, 2003
    Co-Authors: Long Fu, Guoliang Ding, Chunlu Zhang
    Abstract:

    Abstract A dynamic model of air-to-water dual-mode heat pump with screw compressor is presented here. The high-pressure and low-pressure segments are divided into three control volumes, including the refrigerant inside tube, the tube wall and the fluid outside tube that is water or air. Time dependent ordinary differential equations are obtained from the mass and energy balances for each control volume. As the compressor, thermostatic expansion Valve (TEV) body, and Reversing Valve have very small thermal inertias, steady-state models are applied for the compression, throttling, and leakage processes. The relationship between the temperature of the saturated liquid–vapor mixture in TEV’s bulb and the temperature of the refrigerant vapor at the evaporator exit is described with a time dependent ordinary differential equation. System simulation is finally carried out with ‘predictor–corrector’ and ‘adaptive integration step’ methods. Simulated results are in good agreement with the measured data, which lead to conclusion that the model can be used as a tool for the product development.

Guoliang Ding - One of the best experts on this subject based on the ideXlab platform.

  • dynamic simulation of air to water dual mode heat pump with screw compressor
    Applied Thermal Engineering, 2003
    Co-Authors: Long Fu, Guoliang Ding, Chunlu Zhang
    Abstract:

    Abstract A dynamic model of air-to-water dual-mode heat pump with screw compressor is presented here. The high-pressure and low-pressure segments are divided into three control volumes, including the refrigerant inside tube, the tube wall and the fluid outside tube that is water or air. Time dependent ordinary differential equations are obtained from the mass and energy balances for each control volume. As the compressor, thermostatic expansion Valve (TEV) body, and Reversing Valve have very small thermal inertias, steady-state models are applied for the compression, throttling, and leakage processes. The relationship between the temperature of the saturated liquid–vapor mixture in TEV’s bulb and the temperature of the refrigerant vapor at the evaporator exit is described with a time dependent ordinary differential equation. System simulation is finally carried out with ‘predictor–corrector’ and ‘adaptive integration step’ methods. Simulated results are in good agreement with the measured data, which lead to conclusion that the model can be used as a tool for the product development.

  • dynamic simulation of air to water dual mode heat pump with screw compressor
    Applied Thermal Engineering, 2003
    Co-Authors: Long Fu, Guoliang Ding, Chunlu Zhang
    Abstract:

    Abstract A dynamic model of air-to-water dual-mode heat pump with screw compressor is presented here. The high-pressure and low-pressure segments are divided into three control volumes, including the refrigerant inside tube, the tube wall and the fluid outside tube that is water or air. Time dependent ordinary differential equations are obtained from the mass and energy balances for each control volume. As the compressor, thermostatic expansion Valve (TEV) body, and Reversing Valve have very small thermal inertias, steady-state models are applied for the compression, throttling, and leakage processes. The relationship between the temperature of the saturated liquid–vapor mixture in TEV’s bulb and the temperature of the refrigerant vapor at the evaporator exit is described with a time dependent ordinary differential equation. System simulation is finally carried out with ‘predictor–corrector’ and ‘adaptive integration step’ methods. Simulated results are in good agreement with the measured data, which lead to conclusion that the model can be used as a tool for the product development.

Cao Xia - One of the best experts on this subject based on the ideXlab platform.

  • A New Experimental Unit of Testing Capacity for Heat Pump Four-Way Reversing Valve
    Journal of Shanghai Jiaotong University, 2002
    Co-Authors: Cao Xia
    Abstract:

    Exactly testing the capacity of a four way Reversing Valve is the basis of matching it with a heat pump. However, there has been no standard which describes the method of testing in either ARI or ASHRAE. A reasonable way of testing the capacity of revesing Valve was proposed based on the analysis of testing method of solenoid Valve, the research results of the capacity characteristic of heat pump four way Reversing Valve, and the analysis of Chinese national standard draft. The heat pump working states that should be kept stable during the test process were defined. Using the method, a new automatically controlling and high precision experimental unit to measure the capacity curve and the nominal capacity of four way Reversing Valve was established. The results can be applied to the system matching, and therefore, the energy saving can be realized. The accomplishment of the test unit also lays a theoretical and practical foundation to form the standard of heat pump air conditioner four way Reversing Valve.

  • Study and Application of the Dynamic Characteristic for Heat Pump Reversing Valve
    Journal of Shanghai Jiaotong University, 2001
    Co-Authors: Cao Xia
    Abstract:

    This paper set up a dynamic model of the slide and a thermodynamic model of the refrigerant gas sources that drive it to reverse. The computational program was developed based on the above models. Applying the programs to proceed the simulations for the dynamic behavior of the two typical parameters' Reversing Valves, it drew some significant conclusions. The laser Doppler interference system was used to measure the velocity and acceleration of the slide in the Reversing Valve in an N 2 system and it proves that the normal Reversing will always be achieved under the fixed suitable pressure sources. Another refrigerant test unit was also employed for acquiring the pressures of the gas sources that drive the slide to move. The data of the tests verify the exactness of the models.

  • 3D flow analysis in the Reversing Valve of a heat pump
    2000
    Co-Authors: Cao Xia, Chen Jiangping, Chen Zhi-jiu
    Abstract:

    Numerical results are presented and discussed for the 3D flow in paths of the four-way- Reversing-Valve. The body-fitted coordinate is used to discrete the computational region. The finite volume method is utilized to solve the pressure-linked equation. The analysis results have been used in the design and the improvement of the Reversing Valve in Zhejiang Sanhua Group Corporation.

  • Study on the dynamic charateristic of the Reversing system of the heat pump
    2000
    Co-Authors: Cao Xia, Chen Zhijiu
    Abstract:

    This paper presents the dynamic model of the slide and the thermodynamic model of the refrigerant gas sources whose pressure difference drive the slide to reverse. The models are setup basing on the detailed analysis of the Reversing process of the heat pump Reversing system. The dynamic characteristics are obtained for the two typical parameters' Reversing Valves such as velocity, acceleration, displacements etc. The data acquisition system is used for measuring the pressures in the two chambers of the Reversing Valve installed in a heat pump. The results of the tests show the soundness of the simulation ones. The conclusion is that the key parameter of the Reversing Valve decides the qualification of the Reversing process according to the simulation results. The above research results have been applied in the Sanhua Group Corporation.

Luo Jingjing - One of the best experts on this subject based on the ideXlab platform.

  • boiling regeneration type heat source tower heat pump system
    2013
    Co-Authors: Wang Li, Luo Jingjing
    Abstract:

    The utility model discloses a boiling regeneration type heat source tower heat pump system. A heat source tower is respectively connected with a regulating Valve I and a regulating Valve II. The regulating Valve I, a solution heat exchanger, a throttle Valve I and a boiling type regenerator are sequentially connected with a solution pump, and the solution pump is further connected with the solution heat exchanger. The regulating Valve II is connected with a cooling water pump, and the cooling water pump is respectively connected with an outdoor change-over Valve set and the solution heat exchanger. The boiling type regenerator is connected with an external low-grade heat source. The outdoor change-over Valve set is respectively connected with the solution heat exchanger, the heat source tower and an outdoor heat exchanger, and the outdoor heat exchanger is connected with a four-way Reversing Valve. The four-way Reversing Valve is respectively connected with a compressor and a port of an indoor heat exchanger. The port of the indoor heat exchanger is respectively connected with a throttle Valve II and an indoor change-over Valve set. The throttle Valve II is respectively connected with a check Valve I and a check Valve II. The check Valve II is connected with a condenser. The condenser is connected with the check Valve I and the outdoor heat exchanger. A by-pass Valve is respectively connected with the check Valve II and the condenser.

  • boiling regeneration type heat pump system for heat source tower
    2013
    Co-Authors: Wang Li, Luo Jingjing
    Abstract:

    The invention discloses a boiling regeneration type heat pump system for a heat source tower. The heat source tower is respectively connected with an adjusting Valve I and an adjusting Valve II; the adjusting Valve I, a solution heat exchanger, a throttling Valve I, a boiling type regenerator and a solution pump are sequentially connected; the solution pump is further connected with the solution heat exchanger; the adjusting Valve II is connected with a cooling water pump; the cooling water pump is respectively connected with an outdoor change-over Valve group and the solution heat exchanger; the boiling type regenerator is connected with an external low-level heat source; the outdoor change-over Valve group is respectively connected with the solution heat exchanger, the hot source tower and the outdoor heat exchanger; the outdoor heat exchanger is connected with a four-way Reversing Valve; the four-way Reversing Valve is respectively connected with a compressor and a port of an indoor heat exchanger; the port of the indoor heat exchanger is respectively connected with a throttling Valve II and an indoor Reversing Valve group; the throttling Valve II is respectively connected with a one-way Valve I and a one-way Valve II; the one-way Valve II is connected with a condenser; the condenser is connected with the one-way Valve I and the outdoor heat exchanger; and a bypass Valve is respectively connected with the one-way Valve II and the condenser.