Three-mode compound water chilling unit and control method thereof

Abstract

The invention provides a three-mode compound water chilling unit. The three-mode compound water chilling unit comprises a compressor, a one-way valve, a condenser, a drying filter, a throttling device, an evaporator, a gas bypass branch and a liquid bypass branch serially connected in sequence to form a refrigerant loop, wherein the horizontal height of the condenser is higher than the horizontal height of the evaporator; a gas control valve is arranged on the gas bypass branch, and is connected to an intake port of the compressor and an outlet of the one-way valve in parallel; and a liquid control valve is arranged on the liquid bypass branch, and is connected to an inlet of the drying filter and an outlet of the throttling device in parallel. The three-mode compound water chilling unit and a control method thereof, provided by the invention, skillfully blend a gas-phase driven power heat pipe into a gravity heat pipe and steam compression compound technology to build a continuously adjustable three-mode compound water chilling unit; and the unit can fully use a natural cold source, is excellent in energy saving effect, high in reliability, low in initial cost and small in floor area, and has excellent application prospect in such aspects as cooling of large machine rooms.

Description

technical field [0001] The invention belongs to the field of air-conditioning equipment, and in particular relates to a three-mode compound chiller and a control method thereof. Background technique [0002] With the advancement of my country's urbanization and informatization, the types and quantities of building spaces with year-round cooling demand are increasing rapidly, including data room, mobile base station and other high heat density spaces, large public building inner areas, craft workshops , production plants and other special industrial spaces. These building spaces not only need to be cooled in summer, but also need to be supplied with cooling capacity due to their load characteristics or functional requirements in the transition season or even winter. At present, most of these building spaces are cooled by the traditional vapor compression method, and the annual cooling energy consumption is generally high. [0003] In recent years, in order to reduce the ener...

AI Technical Summary

Problems solved by technology

[0006] 2. Frequent start and stop of the unit

[0007] 3. The problem of lubricating oil

However, when the heat pipe is running, the presence of oil will hinder the heat transfer and increase the flow resistance, thereby inhibiting the heat transfer performance of the heat pipe. In addition, the operation of the heat pipe may change the distribution of lubricating oil, which will bring potential danger to the next safe start of the compressor

On the other hand, in order to ensure that the resistance of the heat pipe is small, it also brings many difficulties to the oil return design of the compressor. Refrigerant flow rate cannot guarantee smooth oil return; in flooded units, it is necessary to design a complex oil return system, and it is difficult to install an oil separator

[0008] The Chinese patent with application number CN00200740.1 proposes the idea of ​​pressurizing the gas phase or liquid phase of the heat pipe to form a mechanically driven power heat pipe "heat ring". This power heat pipe can solve the lack of height difference of the traditional gravity heat pipe , instability and other issues, but it only solves the heat transfer problem in the case of positive temperature difference, and cannot solve the heat transfer problem in the case of no temperature difference or negative temperature difference

In addition, because this technology has high requirements for the supercharging device, such as continuous adjustment of small pressure ratio (<1.5), oil-free operation, good sealing, etc., no substantive implementation plan has been proposed, and no corresponding control method has been proposed.

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