The direct cause of gathering pipe network failure was the failure of the pipeline and accessories equipments according to a lot of field investigation .The fault tree was established as the top event of gathering pipeline failure on the basis of the comprehensive analysis of gathering pipeline network failure factors. Considering about the 44 basic events, the descending method was used to analyze the gathering pipeline network failure fault tree, and obtained all 52 minimum cut sets in the system. And the quantitative analysis of the fault tree was carried on. The qualitative analysis was carried on the gathering pipe network and the weakest link was found out in gathering pipe network, which could maintenance the old pipeline network and provide theoretical guidance for the design of the new pipeline network.

Steam injection boiler is one of the main power and energy consumption equipments in oil thermal production. Generally, the high temperature saturated water enthalpy which is separated by the steam separator is used through the heat exchanger. However the water treatment system of the steam injection boiler is so simple and the separated saturated water is rich in calcium，magnesium and other ions which are easy to foul pipe surface and affects the heat transfer efficiency of the heat exchange equipment. Comparing with the case of no using the equipment, the screw expander which is of a selfcleaning ability recycled the waste heat of the saturated water, which can improve the thermal efficiency by 10.2% and save about 4.56×107 kW·h amount to 18 422.4 t of standard coal in the service period. The effect is significant.

n order to more accurately determine the crude oil batching transportation temperature fluctuation, the soil temperature field around pipeline insulation surface drift was studied. For variation characteristics of soil temperature field around underground pipeline in the process of batching transportation of cold and hot crude oil, the non steady heat transfer model was established, and soil temperature field in different period of batching cycles and moments was numerically simulated and analyzed by using CFD software in the process of crude oil batching transportation. The results show that the drift on the thermal insulation surface of soil temperature field has certain regularity, and adiabatic surface with crude oil batching transportation time shows periodic drift, drift period and period of batching cycles of cold and hot oil transportation were the same; drift cycle of thermal insulation surface of soil temperature field and the scope are related to cold and hot cycle on the batch transportation of oil.

The power plant boiler high temperature slag is typically the use of recycled water for cooling the slag, and recycled water slag wasted heat into the cooling tower and the atmosphere. Not only the heat of the slag has not been fully utilized, but also the boiler thermal efficiency and recycled water evaporation were caused by the waste of water resources to a certain extent, and by thermal pollution on the environment. It is very important that Boiler high temperature slag wasted heat recovery for energy conservation, and improved the overall boiler thermal efficiency. The design of the works of three waste heat recovery scheme, the effect of energy saving and economic benefits of each program optimization calculation resulted in cold slag recycling power plant boiler and high temperature slag wasting heat for heating boiler feed water, the cold residue machine released hot water into the low temperature heater between 7# and 8#, there are very significant results and thus reduce the turbine extraction, reduce the turbine power heat rate, and improve the efficiency of the entire power plant power generation. Its findings can be generalized to other power plant boilers and lowtemperature waste heat recycling.