There are a number of Sharp emulators. I am not aware of any that emulate a specific type of computer because anything that can be loaded on the MZ80K will run on the MZ700. Accordingly, I have listed 3 MZ700 emulators, two free and one shareware:
MZxEmu (http://www.sharpmz.org/mfranzenemu.htm ) - I have not used this one but it seems to run fine and comes with a massive amount of downloaded software, mainly games.
Sharp MZ821 Emulator (http://www.sharpmz.org/medekemu.htm ) - This one I use a lot and have downloaded loads of computer languages and other utilities to run on it. Free and excellent.
MZ80Emu (http://mz-800.xf.cz/emu_reg.htm ) - This one is shareware but of an unusual type. Everything works but only for 180 seconds. I also do not find it the easiest to use. I have always used the freeware one above.
PC-1500a Emulator (http://pocket.free.fr/html/soft/emul_pc-1500a_e.html ) - All in French but easy to work out what is going on. I have tried some BASIC and machine code programs on it and all have worked as they should.