Environment-friendly ultrahigh-temperature heat pump mixed working medium and application thereof

Abstract

The invention belongs to the technical field of refrigerants, and particularly relates to an ultrahigh-temperature energy-saving environment-friendly heat pump working medium and application thereof. The mixed working medium is a binary mixed working medium consisting of two components, namely cyclobutane and cyclopentane; and the mixed working medium comprises the following components in percentage by mass: 15 to 90 percent of cyclobutane and 10 to 85 percent of cyclopentane. The binary mixed working medium is obtained by controlling the detailed components forming the working medium, the mass ratio of all the components and the like, especially can be used for preparing a heating temperature of 170 DEG C or above, can be used as an ultra-high-temperature (170 DEG C or above) heat pump working medium, and can be used as a heat pump working medium with the ultra-high-temperature (170 DEG C or above) heat pump working medium. And the device can be applied to the field of high-temperature heat pumps to directly replace coal-fired boilers combusting fossil energy so as to greatly reduce the emission of carbon dioxide, so that the device has more excellent environmental protection performance.

Description

Technical Field

[0001] This invention belongs to the field of refrigerant technology, specifically relating to an environmentally friendly ultra-high temperature heat pump working fluid and its application. Background Technology

[0002] Against the backdrop of profound optimization and accelerated progress in the global energy structure, promoting the decarbonization of heating processes has become an inevitable trend. Industrial heating accounts for more than 20% of global energy consumption. Traditional heating technologies mainly rely on fossil fuels, but their high carbon emissions and low energy efficiency are no longer adequate to meet the urgent needs of energy transition. High-temperature heat pumps, as active heat recovery devices, can use external energy to raise low-grade industrial waste heat to higher temperatures to meet the heating needs of the same or other processes, thereby improving energy efficiency while achieving low-carbon heating. The advantage of high-temperature heat pumps lies in their use of only electricity as input, significantly reducing greenhouse gas emissions, especially when the electricity required for operation is generated from renewable energy sources, and their large-scale, flexible heating potential. Therefore, high-temperature heat pumps can achieve decarbonization of the heating process. High-temperature heat pumps are expected to replace industrial boilers by improving energy efficiency and reducing the use of fossil fuels, fundamentally changing thermal management methods.

[0003] A key aspect of the development of high-temperature heat pumps is the selection of the working fluid. Currently, research on working fluids for heat pumps with heating temperatures below 140℃ is relatively mature, but research on working fluids with heating temperatures above 150℃, especially above 170℃, is less common. High-temperature drying, dyeing, and various chemical processes require large amounts of steam above 170℃; therefore, research on high-temperature heat pump working fluids with heating temperatures above 170℃ is crucial for heat pumps to replace industrial boilers. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, the present invention aims to provide an environmentally friendly ultra-high temperature heat pump working fluid. This fluid, obtained by controlling the detailed components and mass proportions of each component, is a binary mixed working fluid capable of producing heating temperatures of 170°C and above, making it suitable for high-temperature (170°C and above) heat pump applications. Heat pumps using this binary mixed working fluid can replace coal-fired boilers burning fossil fuels, significantly reducing carbon dioxide emissions. Furthermore, compared to coal-fired boilers burning fossil fuels, the heat pump itself has an efficiency greater than 1, thus exhibiting energy-saving characteristics.

[0005] To achieve the above objectives, according to one aspect of the present invention, an environmentally friendly ultra-high temperature heat pump working fluid is provided, which is a binary working fluid composed of two components: cyclobutane and cyclopentane; and the mass percentage concentration of each component in the working fluid is as follows: the mass percentage of cyclobutane is 15% to 90%, and the mass percentage of cyclopentane is 10% to 85%.

[0006] As a further preferred embodiment of the present invention, the mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane mass percentage is 15% to 51%, and cyclopentane mass percentage is 49% to 85%.

[0007] As a further preferred embodiment of the present invention, the mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane mass percentage is 32% to 90%, and cyclopentane mass percentage is 10% to 68%.

[0008] As a further preferred embodiment of the present invention, the mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane mass percentage is 63% to 90%, and cyclopentane mass percentage is 10% to 37%.

[0009] As a further preferred embodiment of the present invention, the mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane is 32% by mass and cyclopentane is 68% by mass.

[0010] As a further preferred embodiment of the present invention, the mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane is 63% by mass and cyclopentane is 37% by mass.

[0011] According to another aspect of the present invention, the present invention provides the application of the above-mentioned environmentally friendly ultra-high temperature heat pump mixed working fluid as a heat pump working fluid.

[0012] As a further preferred embodiment of the present invention, the heating temperature of the heat pump working fluid can reach 170°C or higher.

[0013] According to another aspect of the present invention, the present invention provides a heat pump whose working fluid is the above-mentioned environmentally friendly ultra-high temperature heat pump mixed working fluid.

[0014] As a further preferred embodiment of the present invention, the heat pump is capable of producing steam at a temperature of 170°C or higher.

[0015] In summary, compared with the prior art, the technical solutions conceived in this invention have the following advantages due to the use of a specific ratio of cyclobutane and cyclopentane to construct a cyclobutane / cyclopentane binary mixed working medium (wherein the mass percentage of the cyclobutane component in the mixed working medium is 15% to 90%, and the mass percentage of the cyclopentane component in the mixed working medium is 10% to 85%): 1. The heating temperature can reach 170℃ and above, which can replace coal-fired boilers that burn fossil fuels. The specific heating temperature of the cyclobutane / cyclopentane binary mixture system is affected by the combined proportion of each component. This invention controls the mass proportion of the cyclobutane component in the overall system to 15% to 90%, and the mass proportion of the cyclopentane component in the overall system to 10% to 85%, so that the specific heating temperature of the overall binary mixture system can reach 170℃ and above, and can reach up to 210℃.

[0016] 2. Wide operating temperature range: the entire heat pump system remains under positive pressure even at evaporation temperatures as low as 14°C. This not only allows for full utilization of natural air energy but also prevents outside air from leaking into the system in the event of a leak.

[0017] 3. The sliding temperature is less than 11℃, which is consistent with the superheat of general refrigeration heat pump systems. Therefore, there are no special requirements for the superheat of the system.

[0018] 4. Under the conditions of evaporation temperature of 20℃ and condensation temperature of 170℃, the coefficient of performance is greater than or equal to 1.55; and the pressure ratio is controlled below 30, a two-stage compression heat pump can be realized.

[0019] 5. With an evaporation temperature of 30℃ and a condensation temperature of 180℃, the coefficient of performance (COP) is greater than or equal to 1.43; and the pressure ratio is controlled at 25-26, a two-stage compression heat pump can be achieved.

[0020] 6. With an evaporation temperature of 40℃ and a condensation temperature of 200℃, the coefficient of performance (COP) is greater than or equal to 1.38; and the pressure ratio is controlled between 26 and 28, a two-stage compression heat pump can be achieved.

[0021] 7. Under the conditions of evaporation temperature of 50℃ and condensation temperature of 210℃, the coefficient of performance is greater than or equal to 1.68; and the pressure ratio is controlled below 26, a two-stage compression heat pump can be realized.

[0022] 8. With an ODP value of zero and a GWP value below 20 which is negligible, it has significant environmental advantages.

[0023] In summary, this invention utilizes a specific ratio of cyclobutane and cyclopentane to construct a cyclobutane / cyclopentane binary working fluid, achieving a heating temperature of 170°C and above. Both ODP and GWP values ​​are negligible, making it particularly suitable for use in high-temperature heat pumps to directly replace coal-fired boilers burning fossil fuels, significantly reducing carbon dioxide emissions and thus exhibiting superior environmental performance. Of course, the binary working fluid in this invention is also applicable to heating temperatures below 170°C. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0025] In specific implementations of this invention, the components cyclobutane and cyclopentane are both commonly used working fluids in the fields of refrigeration and cryogenic technology. In the mixed working fluid obtained based on this invention, the sum of the mass percentage concentrations of each component is 100%, wherein the mass percentage of cyclobutane is 15%–90%, and the mass percentage of cyclopentane is 10%–85%.

[0026] Example 1 Two working media, cyclobutane and cyclopentane, are taken and, in the liquid phase, 15% by mass of cyclobutane and 85% by mass of cyclopentane are thoroughly physically mixed to obtain a non-azeotropic working media.

[0027] Example 2 Two working media, cyclobutane and cyclopentane, were taken and thoroughly physically mixed in the liquid phase. A non-azeotropic mixture was obtained.

[0028] Example 3 Two working media, cyclobutane and cyclopentane, were taken and thoroughly physically mixed in the liquid phase. A non-azeotropic mixture was obtained.

[0029] Example 4 Two working media, cyclobutane and cyclopentane, were taken and, in the liquid phase, 51% by mass of cyclobutane and 49% by mass of cyclopentane were thoroughly physically mixed to obtain a non-azeotropic working media.

[0030] Example 5 Two working media, cyclobutane and cyclopentane, were taken and thoroughly physically mixed in the liquid phase. A non-azeotropic mixture was obtained.

[0031] Example 6 Two working media, cyclobutane and cyclopentane, are taken and fully physically mixed in the liquid phase. A non-azeotropic mixture is obtained.

[0032] Example 7 Two working media, cyclobutane and cyclopentane, were taken and thoroughly physically mixed in the liquid phase. A non-azeotropic mixture was obtained.

[0033] Example 8 Two working media, cyclobutane and cyclopentane, are taken and, in the liquid phase, 90% by mass of cyclobutane and 10% by mass of cyclopentane are thoroughly physically mixed to obtain a non-azeotropic working media.

[0034] The basic physical properties of the two components, cyclobutane and cyclopentane, used in the above embodiments are shown in Table 1: Table 1: Physical properties of cyclobutane and cyclopentane

[0035] Regarding the mixed working fluids obtained in each embodiment: The calculation conditions for Example 1 are as follows: evaporation temperature is 50°C, condensation temperature is 210°C, subcooling is 5°C, and superheat is 10°C.

[0036] The calculation conditions for Examples 2-4 are as follows: evaporation temperature is 40℃, condensation temperature is 200℃, subcooling is 5℃, and superheat is 10℃.

[0037] The calculation conditions for Examples 5-7 are as follows: evaporation temperature is 30℃, condensation temperature is 180℃, subcooling is 5℃, and superheat is 10℃.

[0038] The calculation conditions for Example 8 are as follows: evaporation temperature is 20°C, condensation temperature is 170°C, subcooling is 5°C, and superheat is 10°C.

[0039] The calculations were performed using a two-stage compression, one-stage throttling, and incomplete cooling cycle.

[0040] The compression process during theoretical cyclic calculations is isentropic compression.

[0041] The theoretical cycle calculations mainly focus on comparing key parameters such as pressure ratio, calorific value per unit volume, coefficient of performance, boiling point (bubble point) temperature, dew point temperature, glide temperature, and critical temperature. The results of the comparison are shown in Table 2. Table 2: Theoretical Cycle Calculation Parameters for High-Temperature Heat Pump Operation

[0042] Note: 1. The pressure ratio is the ratio of condensation pressure to evaporation pressure; the evaporation pressure is the saturated liquid pressure at the evaporation temperature, and the condensation pressure is the saturated liquid pressure at the condensation temperature. 2. When the mass percentage of cyclobutane is less than 15%, the dew point temperature of the mixture is higher than 45°C, making it difficult to directly utilize low-grade heat sources below 50°C; when the mass percentage of cyclobutane is higher than 90%, the critical temperature of the mixture is lower than 190°C, making it difficult to produce heat above 170°C.

[0043] The results show that: 1. The critical temperature of all embodiments is above 190°C, reaching a maximum of 229°C, so the heating temperature can reach above 170°C; 2. It has a wide operating temperature range. Even when the evaporation temperature is as low as about 14°C, the entire heat pump system is still under positive pressure, thus preventing outside air from entering the system in the event of a leak. 3. The glide temperature is less than 11℃, which is consistent with the superheat of a general refrigeration heat pump system. Therefore, there are no special requirements for the superheat of the system. 4. With an ODP value of zero and a GWP value of only around 20, which is negligible, it has significant environmental advantages.

[0044] It is evident that the high-temperature heat pump of this invention, using fossil fuels as its working fluid, can directly replace coal-fired boilers.

[0045] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An environmentally friendly ultra-high temperature heat pump working fluid, characterized in that, The mixed working fluid is a binary mixed working fluid composed of two components: cyclobutane and cyclopentane; and the mass percentage concentration of each component in the mixed working fluid is as follows: the mass percentage of cyclobutane is 15% to 90%, and the mass percentage of cyclopentane is 10% to 85%.

2. The environmentally friendly ultra-high temperature heat pump working fluid according to claim 1, characterized in that, The mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane is 15%–51% by mass, and cyclopentane is 49%–85% by mass.

3. The environmentally friendly ultra-high temperature heat pump working fluid according to claim 1, characterized in that, The mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane is 32%–90% by mass, and cyclopentane is 10%–68% by mass.

4. The environmentally friendly ultra-high temperature heat pump working fluid according to claim 1, characterized in that, The mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane is 63%–90% by mass, and cyclopentane is 10%–37% by mass.

5. The environmentally friendly ultra-high temperature heat pump working fluid according to claim 1, characterized in that, The mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane is 32% by mass, and cyclopentane is 68% by mass.

6. The environmentally friendly ultra-high temperature heat pump working fluid according to claim 1, characterized in that, The mass percentage concentrations of each component in the mixed working fluid are as follows: cyclobutane is 63% by mass, and cyclopentane is 37% by mass.

7. The application of the environmentally friendly ultra-high temperature heat pump mixed working fluid according to any one of claims 1-6 as a heat pump working fluid.

8. The application according to claim 7, characterized in that, The heating temperature of the heat pump working fluid can reach 170°C or higher.

9. A heat pump, characterized in that, The working fluid of the heat pump is the environmentally friendly ultra-high temperature heat pump mixed working fluid as described in any one of claims 1-6.

10. The heat pump according to claim 9, characterized in that, This heat pump can produce steam at temperatures of 170°C and above.

Images