| The heat-pump unit system running under variational conditions is now a popular aspect of heat-pump researches. As the actual conditions heat-pump systems running under are non-standard, the theoretical and traditional investigations are inadequate to describe properly the actual situation of system parameters. Besides, the heat-pump systems consume quite a lot electric power as a whole, thus, in order to optimize the operation and to save the cost of widely used heat-pump systems, it is high time we investigated under variational conditions. That is what this paper mainly deals with.The heat-pump air-conditioners are actually a compact form of the heat-pump unit systems. Therefore, the similarity of the two kinds of systems is an advantage that we could take to futher the investigations. Combined the reasearches of variational running conditions with the heat-pump air-conditioner testing platform (established according to the national criterion) is a beneficial aspect of extending the researches of heat-pump systems.The paper mainly deals with:1) Establishment of the mathematical models of major units in a heat-pump unit system, on the basis of the distributing parameter methods. Some kinds of simplifications are introduced while at the same time the overall modeling precision is within the allowed ranges.2) Investigations of variational running conditions; actual examples also presented.3) Investigations of a heat-pump testing platform, Combined with the heat-pump unit systems, the investigations are in the aspect of variational operation; introduction and analyses of a new testing method. |
