The growth and application of water ring heat pump VRV products abroad

Abstract: Introduce a new type of air-conditioning method that has emerged in foreign countries in the past ten years. This article introduces the development and application of VRV water ring heat pump products abroad, related encouragement policies, and the prospect of domestic promotion. And according to the requirements of the comprehensive part-load performance coefficient of the equipment in the “Design Standards for Energy Efficiency of Public Buildings” in Beijing in 2005, the energy-saving performance of the equipment is discussed.
1. Overview of the application of
　　water ring heat pump VRV Water ring heat pump VRV (water-cooled VRV) is a branch of the VRV series. Water loop + built-in board replacement), forming a kind of water pipe that does not enter the room, but only in the non-dedicated machine room of the shaft and the main machine; the main machine is located in the indoor non-dedicated equipment room, which is smaller in size and weight and can be stacked; in use A new type of air-conditioning method combining centralization and decentralization.
　　It can be combined with a variety of energy forms, and applied to various new, renovation or addition projects that have existing cold and heat sources, or exist in internal and external areas, or require cold and heat at the same time. The scale of the building ranges from a few hundred square meters to hundreds of thousands of square meters.
　　The host uses R410A refrigerant, and there are two types of heat pump and heat recovery. Among them, the concept of heat recovery has been applied in air-cooled VRV. With this model, it is possible to simultaneously provide cooling and heating in the same refrigerant system.
1.1. Overview
　　of development abroad　　 At the end of the 1980s and the beginning of the 1990s, the Japanese economy was in a period of rapid development. In terms of economic scale, Japan’s per capita GDP in the early 1990s was 29,524 U.S. dollars, ranking first in the world, surpassing the United States by 20%. Various social constructions have developed rapidly. It was also from this period that the Japanese government began to “implement a sustainable development strategy”, “taking the development of a circular economy and the establishment of a circular society as an important way and way to achieve a sustainable development strategy.”
　　Water loop heat pump VRV is based on this background, responding to the needs of a large number of renovation/new projects, recycling, and sustainable development.
　　After more than ten years of development, water ring heat pump VRV has achieved rapid development in developed countries such as Japan and Europe, and has now developed to the second generation of products. At the end of 2005, the product successively won the 2005 Japan Energy Conservation Award-Energy Conservation Chairman Award (Note 1) and the encouragement application of European government tax incentive policies (Note 2).
1.2 Prospects for domestic promotion
1.2.1 Sustainable development of energy and environment
　　Since the beginning of the new century, with the beginning of building a well-off society in an all-round way, China’s economic scale has continued to expand, and China has become the second largest after the United States. In the world market, industrialization and urbanization have accelerated in an all-round way. The contradiction between resource supply and demand and environmental problems have also become increasingly exacerbated. At the same time of economic development, China is also the world’s second largest energy consumer and second largest CO2 emitter (The Necessity of Energy Conservation for Central Air Conditioning in China) by the Cooling, Heating and Air Conditioning Network. In 2004, large-scale power cuts in various cities in China have severely affected the country’s economic development and the lives of ordinary people. High energy consumption per unit of GDP and high environmental costs have become the primary factors restricting the healthy and sustainable development of our country.
　　The Fifth Plenary Session of the 16th Central Committee of the Communist Party of China proposed that by the end of the 11th Five-Year Plan (2010), energy consumption per unit of GDP will be reduced by 20% compared to the end of the Tenth Five-Year Plan. In the future, the National Bureau of Statistics and the National Development and Reform Commission will also include energy consumption per unit of GDP as an important evaluation content for the economic growth evaluation indicators of various localities.
　　Experts pointed out that although China’s energy consumption is astonishing, there is still a lot of room for energy conservation. With the development of the global economy to the emerging information industry and the continuous improvement of people’s requirements for comfort in life, more and more energy is consumed in non-traditional industries.
　　In the commercial and service industries, central air-conditioning is the main energy-consuming equipment. According to statistics from Chongqing and Shanghai, the electricity consumption of central air-conditioning accounts for 23% and 31.1% of the city’s total electricity consumption respectively. In addition, the central air conditioner of civil, public and commercial buildings in China generally has the problem of high energy consumption. Generally, the energy consumption of central air conditioners accounts for about 50% of the total energy consumption of the entire building, and it may be as high as 60% for shopping malls and complex buildings. . (The Necessity of Energy Conservation for Central Air Conditioning in China by the Cooling and Heating Air Conditioning Network)
　　Based on the above background, both energy conservation and new energy development, renewable energy utilization and the application of environmental protection technologies are of great significance to the sustainable development of our country in economic development.
　　Therefore, due to its own characteristics, water ring heat pump VRV has a very broad market development space for promotion and application in China.
1.2.2 Application of VRV
　　water ring heat pump The design and use of VRV water ring heat pump mainly have three major parts: energy selection, cooling water pipeline and VRV-W. The optimized combination of the three can make the initial investment and operating cost of the entire system economical and reasonable.
　　Since the normal working water temperature of water ring heat pump VRV is between 15-45°C, there are three types of energy it can use.
　　In fact, water ring heat pump VRV can use a variety of energy forms, as long as it can meet the requirements. The temperature of the incoming water should be between 15-45°C. In addition, this type of air conditioning system can also be used in combination with conventional ice storage and water tank heat storage, and can use the peak-to-valley difference
　　in the design of cooling water piping to a certain extent. You can refer to the design of conventional water systems. The pressure of the VRV host of the water ring heat pump can reach 1.96MPa.
　　The design of VRV-W can refer to the selection design of air-cooled VRV.
　　There are several points to note: First, the design of the water pipeline, the reasonable choice of the shaft location, can make the host as close to the use space as possible, and reduce the tube length loss of the refrigerant pipeline; Second, because the water ring heat pump VRV host has a built-in plate heat exchanger The size is small, and it is more sensitive to dirty blocking and corrosion, so a closed loop system must be adopted, that is, a closed cooling water tower or an open cooling water tower + plate replacement.
2. Introduction to the application of water ring heat pump VRV in foreign countries
2.1 Newly-built project ”
　　Iidabashi No.1 Building”
　　The project is located in Osaka, Japan, with a construction area of ​​50,000 square meters. The purpose of the project is office building + residential building. It will be put into use in 2000. The whole system uses 346 VRV water ring heat pumps (3,086HP), and 412 indoor units (duct type). The fresh air adopts 277 total heat exchangers. The system meets the needs of users for high-end positioning of buildings and roof space as parking lots and gardens.
Iidabashi Daiichi Building won the Building Architects Association Award.
　　The JAL City Hotel
　　project is located in Tokyo, Japan, with a construction area of ​​5,400 square meters. It is used as a hotel and was put into use in 1997. The whole system uses 33 VRV water ring heat pumps and 1 closed cooling tower (175 tons). The adoption of this system solves the user’s problem of limited space on the roof and surrounding space, and meets the user’s needs for saving useful space and centralized management.
　　Most JAL city hotels in Japan use a water loop heat pump VRV system.
　　The Hilton Hotel
　　project is located in Manchester, England. It is used as a hotel and was completed at the end of 2006. The entire building uses 29 heat recovery water loop heat pump VRVs in the 290 rooms in the guest rooms. The adoption of this system meets the local requirements for the limitation of CO2 emission efficiency.

2.2 remodeling projects
　　of new large building
　　project is located in Osaka, Japan, construction area of 80,000 square meters, single construction area of over 8,000 square meters, for the purposes of shops, transformation completion time of 2004. The whole system uses 139 VRV water ring heat pumps, 700 indoor units, and 2 closed cooling towers (330*2 tons). Before the renovation, after years of use of the entire building, the original air-conditioning system could no longer meet the existing load requirements, but the main equipment such as the refrigeration unit, water circulation pipes, etc. have not reached the end of their service life; due to different room orientations, different locations, heating and cooling requirements Seriously unbalanced. The system meets the needs of users to use the original cold and heat sources, supplement the insufficient load of the system, use in zones, centralize management, and charge by households. The ultimate goal is that the entire building cannot be closed during the renovation process.
　　CLOTH HALL COURT
　　The project is located in Leeds University, UK, with a building area of ​​3,000 square meters, which is used as a college. The whole system uses 12 VRV water ring heat pumps and 65 indoor units. The building is a well-known cultural relic building in the area. It is a second-class preservation object. Its appearance cannot be changed in any way, and its internal space is very limited. The adoption of the system solves the restrictions brought by these specific situations, while ensuring a shorter construction period and lower operating costs for users.
3 Energy-saving analysis of water loop heat pump VRV
　　1) Refrigeration conditions: As there is no relevant standard in China for reference, it is only based on the Beijing Municipal Construction (Heat pump) The provisions of the unit, make a simple analysis of it. The following table reflects the COP and comprehensive partial load performance coefficient of water ring heat pump VRV and a certain American brand centrifuge:
　　IPLV=2.3%×A+41.5% ×B+46.1% ×C+10.1% ×D
A—100% Coefficient of performance under load (W/W) Cooling water inlet temperature 30℃
B—75% Coefficient of performance under load (W/W) Cooling water inlet temperature 26℃
C—50% Coefficient of performance under load (W/W) cooling Water inlet temperature 23℃
D-25% load performance coefficient (W/W) Cooling water inlet temperature 19℃
　　It can be seen from the above that the comprehensive partial load performance coefficient of water ring heat pump VRV is much higher than the “standard” for centrifugal Machine (5.1) requirements. Generally, the problem of efficiency attenuation in winter heating caused by air-cooled VRV due to low outdoor temperature (required to be greater than COP1.8) is also completely absent for water loop heat pump VRV.
　　If the IPLV is used as its operating economic index to analyze, and the power consumption under each load rate is substituted into the corresponding positions of A, B, C, D, the power consumption can be reflected to a certain extent.
　　2) Heating condition: The above analysis is the cooling condition. During heating operation in winter, there are many situations in its energy saving due to the different energy configuration and utilization methods:
　　Consider whether there are internal and external partitions:
　　1. There are inner and outer zones: By transferring the residual heat from the inner zone to the outer zone, the heat source can be saved;
　　2．No internal and external partitions: the system bears the heat load of the entire building.
　　Consider according to the form of energy used:
　　1. Conventional energy:
　　If a boiler is used, it can be used in conjunction with a hot water storage tank. Because the water temperature required by the water ring heat pump VRV is not high, the low-cost electricity of the trough can be achieved, saving operating costs, and the selection of the boiler can also be reduced accordingly.
　　If the municipal heating network is adopted, and most areas still use the price per square meter at present, the advantages will be difficult to reflect
　　2. Low-grade energy and renewable/new energy
　　comprehensively use these energy sources, whether it is cooling or heating, its energy consumption is far higher than conventional energy. And because these energy sources are very cheap when they are available, a lot of operating costs can also be saved.
　　What needs attention is the environmental impact when certain types of energy are used.
　　To sum up, as countries around the world are paying more and more attention to energy conservation, environmental protection and sustainability along with the development, as a new air-conditioning method, water loop heat pump VRV will become a new and very important one in the future air-conditioning method. Kind of choice