CH714328A2 - Compression heat pump system with steam extraction for heat recovery. - Google Patents

Abstract

This invention relates to a compression heat pump system with steam extraction for heat recovery. Part of the refrigerant flow is removed from the compressor at an intermediate pressure (1) while the remaining flow is compressed to the final pressure difference. Thus, in heat recovery applications, this system makes it possible, among other things, to produce heat, cold and / or electricity.

Description

Description

Object [0001] The invention relates to a compression heating and / or refrigeration system with steam extraction at an intermediate pressure, which makes it possible to increase the heat or cold production capacity of the installation and, thus, , increase its effectiveness.

Description of the invention

State of the art [0002] In machines of the heat pump type it is known, in practice, to increase the efficiency, to proceed to the injection of steam, at an intermediate pressure, at the compressor. As for steam extraction, it is frequently used in power generation systems, with the same objective of increasing the efficiency of the system. It is commonly referred to as steam cycle withdrawal for medium to large power plants or the Organic Rankine Cycle (ORC) for small power installations. Until now, the only case of using steam extraction in a heating and / or refrigeration system is listed in an absorption refrigeration system in which the compressor is used to boost the performance of the system. This use was the subject of a patent of invention: Malewski et al., US Patent No. 4,505,133; Although this invention has since fallen into the public domain, it has been absorbed by refrigeration systems.

Disadvantages [0003] Despite the use of a booster, the fact remains that the coefficient of performance (COP) of the absorption systems is relatively low (compared to that of a compression machine). Its performance is interesting only for large thermal powers, its use is limited to large installations. Moreover, in its design, this system, described in the patent cited above, can be used only for refrigeration.

Technical Problems and Solutions [0004] This present invention, based on two well-known thermal cycles namely the vapor compression cycle and the Organic Rankine Cycle (ORC), is intended to make tri-generation of energy. That is, depending on the application, to produce hot (for heating) cold (for refrigeration) and / or electricity. This objective is achieved, as claimed in claim 1, by withdrawing a portion of the compressor vapor flow (in the compression cycle) at an intermediate pressure for use in the ORC cycle.

Advantages [0005] In addition to making tri-generation of energy, this system makes it possible to have a better efficiency and / or a thermal capacity. Indeed, because the vapor withdrawn is compressed from the low pressure to an intermediate pressure, the amount of electricity consumed by the compressor is less. In addition, if we consider that a small part of the total flow of steam is extracted from the compressor and passes through the generator, it results in a lower demand for thermal power at the latter.

Detailed explanation

Enumeration of Figures [0006] The invention will be explained in more detail with the aid of an exemplary embodiment represented by the drawings below:

In fig. 1 is shown the configuration with an expansion valve.

Fig. 2 shows a configuration where this expansion valve is replaced by a turbine.

Fig. 3 corresponds to the replacement of the exhaust compressor by two separate compressors. Embodiment of the Invention [0007] The working fluid used is an organic fluid of the family of refrigerants. Through the compressor, one part of the working fluid is compressed to an intermediate pressure (P) 1 while the other part is compressed to the high pressure (P ·,) 2. At the pressure P, , the steam is condensed by passing through a heat exchanger used as a low temperature condenser (LT condenser). So, the steam turns into liquid 3 which is

Claims (6)

claims 1. An energy conversion system operating according to the vapor compression cycle in which the following operations are carried out: extraction after the first stage of the compressor of at least a portion of the flow of the refrigerant vapor at an intermediate pressure favorable to its condensation and compression of the remaining vapor flow d2 - at the second stage of the compressor - to the final pressure thereby reducing the energy required by the compressor, injection of this flow d! refrigerant extracted from the compressor in a heat exchanger to turn it into a liquid; pumping this liquid to sufficient pressure for the purpose of using it for heat recovery. An energy conversion system according to claim 1, wherein the first stage of the compressor and the second stage of the compressor are represented by two or more completely separate compressors. 3. An energy conversion system according to claim 1, wherein said pumped liquid of flow di is then evaporated in a heat exchanger used as a generator. 4. An energy conversion system according to claims 1 and 3, wherein, at the output of the generator, the steam is expanded through an expansion valve and then mixed with the flow vapor d2 from the second stage of the compressor. The mixture thus obtained is condensed in a heat exchanger, then expanded through an expansion valve and then evaporated in another heat exchanger to finally be sucked by the compressor. 5. An energy conversion system according to claim 4, wherein an exchanger is used which acts as a regenerator to preheat the flow liquid di, between the pump and the generator, with the flow mixture d. + d2 coming out of the heat exchanger in which it is condensed. 6. An energy conversion system according to claims 4 and 5, wherein the steam flow relief valve d! is replaced by a turbo-generator which, in passing, will produce electricity.